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Sample records for boron 10 target

  1. Enrichment of boron 10

    International Nuclear Information System (INIS)

    Coutinho, C.M.M.; Rodrigues Filho, J.S.R.; Umeda, K.; Echternacht, M.V.

    1990-01-01

    A isotopic separation pilot plant with five ion exchange columns interconnected in series were designed and built in the IEN. The columns are charged with a strong anionic resin in its alkaline form. The boric acid solution is introduced in the separation columns until it reaches a absorbing zone length which is sufficient to obtain the desired boron-10 isotopic concentration. The boric acid absorbing zone movement is provided by the injection of a diluted hydrochloric acid solution, which replace the boric acid throughout the columns. The absorbing zone equilibrium length is proportional to its total length. The enriched boron-10 and the depleted boron are located in the final boundary and in the initial position of the absorbing zones, respectively. (author)

  2. Boron-10 ABUNCL Active Testing

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Siciliano, Edward R.

    2013-07-09

    The Department of Energy Office of Nuclear Safeguards and Security (NA-241) is supporting the project Coincidence Counting With Boron-Based Alternative Neutron Detection Technology at Pacific Northwest National Laboratory (PNNL) for the development of a 3He proportional counter alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a system based upon 10B-lined proportional tubes in a configuration typical for 3He-based coincidence counter applications. This report provides results from testing of the active mode of the General Electric Reuter-Stokes Alternative Boron-Based Uranium Neutron Coincidence Collar (ABUNCL) at Los Alamos National Laboratory using sources and fuel pins.

  3. Meeting the challenge of homogenous boron targeting of heterogeneous tumors for effective boron neutron capture therapy (BNCT)

    International Nuclear Information System (INIS)

    Heber, Elisa M.; Trivillin, Veronica A.; Itoiz, Maria E.; Rebagliati, J. Raul; Batistoni, Daniel; Kreimann, Erica L.; Schwint, Amanda E.; Nigg, David W.; Gonzalez, Beatriz N.

    2006-01-01

    BNCT is a tumor cell targeted radiation therapy. Inadequately boron targeted tumor populations jeopardize tumor control. Meeting the to date unresolved challenge of homogeneous targeting of heterogeneous tumors with effective boron carriers would contribute to therapeutic efficacy. The aim of the present study was to evaluate the degree of variation in boron content delivered by boronophenylalanine (BPA), GB-10 (Na 2 10 B 10 H 10 ) and the combined administration of (BPA+GB-10) in different portions of tumor, precancerous tissue around tumor and normal pouch tissue in the hamster cheek pouch oral cancer model. Boron content was evaluated by ICP-AES. The degree of homogeneity in boron targeting was assessed in terms of the coefficient of variation ([S.D./Mean]x100) of boron values. Statistical analysis of the results was performed by one-way ANOVA and the least significant difference test. GB-10 and GB-10 plus BPA achieved respectively a statistically significant 1.8-fold and 3.3-fold increase in targeting homogeneity over BPA. The combined boron compound administration protocol contributes to homogeneous targeting of heterogeneous tumors and would increase therapeutic efficacy of BNCT by exposing all tumor populations to neutron capture reactions in boron. (author)

  4. Real-time boronization in PBX-M using erosion of solid boronized targets

    International Nuclear Information System (INIS)

    Kugel, H.W.; Timberlake, J.; Bell, R.

    1994-01-01

    Thirty one real-time boronizations were applied to PBX-M using the plasma ablation of solid target probes. More than 17 g of boron was deposited in PBX-M using this technique. The probes were positioned at the edge plasma to optimize ablation and minimize spallation. Auger depth profile analysis of poloidal and toroidal deposition sample coupon arrays indicate that boron was transported by the plasma around the torus and deep into the divertors. During discharges with continuous real-time boronization, low-Z and high-Z impurities decreased rapidly as plasma surfaces were covered during the first 20--30 discharges. After boronization, a short-term improvement in plasma conditions persisted prior to significant boron erosion from plasma surfaces, and a longer term, but less significant, improvement persisted as boron farther from the edge continued gettering. Real-time solid target boronization has been found to be very effective for accelerating conditioning to new regimes and maintaining high performance plasma conditions

  5. Boron-10 ABUNCL Prototype Initial Testing

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Siciliano, Edward R.

    2012-12-01

    The Department of Energy Office of Nuclear Safeguards and Security (NA-241) is supporting the project Coincidence Counting With Boron-Based Alternative Neutron Detection Technology at Pacific Northwest National Laboratory (PNNL) for the development of a 3He proportional counter alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a system based upon 10B-lined proportional tubes in a configuration typical for 3He-based coincidence counter applications. This report provides results of initial testing of an Alternative Boron-Based Uranium Neutron Coincidence Collar (ABUNCL) design built by General Electric Reuter-Stokes. Several configurations of the ABUNCL models, which use 10B-lined proportional counters in place of 3He proportional counters for the neutron detection elements, were previously reported. The ABUNCL tested is of a different design than previously modeled. Initial experimental testing of the as-delivered passive ABUNCL was performed, and modeling will be conducted. Testing of the system reconfigured for active testing will be performed in the near future, followed by testing with nuclear fuel.

  6. Boron containing magnetic nanoparticles for neutron capture therapy--an innovative approach for specifically targeting tumors.

    Science.gov (United States)

    Tietze, Rainer; Unterweger, Harald; Dürr, Stephan; Lyer, Stefan; Canella, Lea; Kudejova, Petra; Wagner, Franz M; Petry, Winfried; Taccardi, Nicola; Alexiou, Christoph

    2015-12-01

    The selective delivery of (10)B into the tumor tissue remains to be further improved for successful and reliable Boron Neutron Capture Therapy applications. Magnetic Drug Targeting using intraarterially administered superparamagnetic nanoparticles and external magnetic fields already exhibited convincing results in terms of highly efficient and selective drug deposition. Using the same technique for the targeted (10)B delivery is a promising new approach. Here, systematic irradiation experiments of phantom cubes containing different concentrations of boron and nanoparticles as well as varying three-dimensional arrangements have been performed. Copyright © 2015. Published by Elsevier Ltd.

  7. Electrophoretic deposition of boron-10 in neutron detectors electrodes

    International Nuclear Information System (INIS)

    Oliveira Sampa, M.H. de; Vinhas, L.A.; Vieira, J.M.

    1990-01-01

    Process of boron-10 electrophoresis on large area of aluminum substrates was developed with the aim of using them in the construction of neutron detectors. After definition and optimization of the boron electrophoresis parameters, depositions of boron-10 on aluminum cylinders were performed and used as electrodes in gamma compensated and non-compensated ionization chambers and in proportional detectors. These prototypes were designed and builded at IPEN-CNEN-SP, and submited for characterization tests at IEA-R1 reactor, and they fulfil the technical specifications of the project. (author) [pt

  8. Analytical techniques for boron and boron 10 analysis in a solid experimental tumor EO.771

    International Nuclear Information System (INIS)

    Porschen, W.; Marx, J.; Feinendegen, L.E.

    1987-01-01

    If a tumor can be preferentially loaded with a suitable boron-10 compound and irradiated with thermal neutrons, malignant cells can be selectively destroyed via the α-particle + Li 7-nucleus from the reaction 10 B(n,α) 7 Li. Neutron capture therapy with two boron-10 amino acid analogs of low toxicity has been tested in recent years: (a) trimethylamine carboxyborane, (A3) and (b) amine-carboxyborane, (A7). Now the boron-10 glycineamide analog (A8), amineboryl carboxamide has been synthsized; it contains 13.81% boron (90% Boron 10+10% Boron 11) and shows a very low toxicity in mice. The effects of this compund were tested on the syngeneic solid adenocarcinoma EO 771 on the right hind leg of male C57 BL/6J mice under standard conditions, by measuring tumor volume growth delay and cell cycle changes using flow cytometry. Boron distribution between tumor and muscle was analyzed by emission spectroscopy with inductively coupled plasma (ICP) following injection of a suspension of peanut oil emulsion. In addition, boron-10 concentration in the tumor were analyzed with prompt γ-activation analysis and neutron capture radiography (Kodak-Pathe LR115) at the MRR reactor in Brookhaven after i.p. injection of 0.4 mg/g A8. Application of A8 alone (0.4 mg/g i.p.) or thermal neutron irradiation of the tumor EO. 771 produced a tumor growth delay of 1-2 days for tumor volume doubling. Application of the boron 10 glycine-amide analog A8 i.p. plus 5x10 12 n/cm 2 resulted in a growth delay of 3-6 days. In contrast intratumoral application of A8 plus 4x10 12 n/cm 2 neutrons gave a growth delay of 7-14 days; the fraction of (G2+M) cells rose from 35% (neutrons alone) to 52%, as evaluated from flow cytometry. (orig.)

  9. Folate receptor-mediated boron-10 containing carbon nanoparticles as potential delivery vehicles for boron neutron capture therapy of nonfunctional pituitary adenomas.

    Science.gov (United States)

    Dai, Congxin; Cai, Feng; Hwang, Kuo Chu; Zhou, Yongmao; Zhang, Zizhu; Liu, Xiaohai; Ma, Sihai; Yang, Yakun; Yao, Yong; Feng, Ming; Bao, Xinjie; Li, Guilin; Wei, Junji; Jiao, Yonghui; Wei, Zhenqing; Ma, Wenbin; Wang, Renzhi

    2013-02-01

    Invasive nonfunctional pituitary adenomas (NFPAs) are difficult to completely resect and often develop tumor recurrence after initial surgery. Currently, no medications are clinically effective in the control of NFPA. Although radiation therapy and radiosurgery are useful to prevent tumor regrowth, they are frequently withheld because of severe complications. Boron neutron capture therapy (BNCT) is a binary radiotherapy that selectively and maximally damages tumor cells without harming the surrounding normal tissue. Folate receptor (FR)-targeted boron-10 containing carbon nanoparticles is a novel boron delivery agent that can be selectively taken up by FR-expressing cells via FR-mediated endocytosis. In this study, FR-targeted boron-10 containing carbon nanoparticles were selectively taken up by NFPAs cells expressing FR but not other types of non-FR expressing pituitary adenomas. After incubation with boron-10 containing carbon nanoparticles and following irradiation with thermal neutrons, the cell viability of NFPAs was significantly decreased, while apoptotic cells were simultaneously increased. However, cells administered the same dose of FR-targeted boron-10 containing carbon nanoparticles without neutron irradiation or received the same neutron irradiation alone did not show significant decrease in cell viability or increase in apoptotic cells. The expression of Bcl-2 was down-regulated and the expression of Bax was up-regulated in NFPAs after treatment with FR-mediated BNCT. In conclusion, FR-targeted boron-10 containing carbon nanoparticles may be an ideal delivery system of boron to NFPAs cells for BNCT. Furthermore, our study also provides a novel insight into therapeutic strategies for invasive NFPA refractory to conventional therapy, while exploring these new applications of BNCT for tumors, especially benign tumors.

  10. Boron-Proton Nuclear-Fusion Enhancement Induced in Boron-Doped Silicon Targets by Low-Contrast Pulsed Laser

    Directory of Open Access Journals (Sweden)

    A. Picciotto

    2014-08-01

    Full Text Available We show that a spatially well-defined layer of boron dopants in a hydrogen-enriched silicon target allows the production of a high yield of alpha particles of around 10^{9} per steradian using a nanosecond, low-contrast laser pulse with a nominal intensity of approximately 3×10^{16}  W cm^{−2}. This result can be ascribed to the nature of the long laser-pulse interaction with the target and with the expanding plasma, as well as to the optimal target geometry and composition. The possibility of an impact on future applications such as nuclear fusion without production of neutron-induced radioactivity and compact ion accelerators is anticipated.

  11. Colorimetric determination of Boron-10 in macromolecular delivery agents

    Energy Technology Data Exchange (ETDEWEB)

    Camillo, Maria A.P.; Moura, Eduardo [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Centro de Biologia Molecular]. E-mail: mcamillo@ipen.br; Queiroz, Alvaro A.A.A.de [Universidade Federal de Itajuba, MG (Brazil). Inst. de Ciencias Exatas. Dept. de Fisica e Quimica]. E-mail: alencar@unifei.edu.br

    2005-07-01

    A polyglycerol with dendritic structure (PGLD) was synthesized by the ring opening polymerization of deprotonated glycidol using a polyglycerol as core functionality in a step-growth process denominated divergent synthesis. After PGLD reaction with {sup 10}B-enriched boric acid there was a marked increase in the bulk viscosity of the PGLD dendrimer evidencing the polyester formation. Gel permeation chromatography (GPC) analysis was used to characterize the molecular weight and the polydispersivity of the synthesized PGLD dendrimer. A dendritic polyglycerol structure with M{sub n} value of 16.7 kDa and a narrow polydispersivity (M{sub w}/M{sub n} = 1.05) was obtained in this work. {sup 1}H-NMR and {sup 13}C-NMR measurements were employed to assess the degree of branching (DB) in PGLD. The DB of 0.85 indicates the tendency of a dentritic structure for the PGLD synthesized in this work. The boron-10 concentration was dependent of the PGLD generation. A selective reagent, curcumine, was studied for spectrophotometric determination of boron in polyglycerol dendrimers. Boron reacts with curcumine to form a complex, which has a maximum absorption peak at 552 nm. Under the optimal conditions, Beer's law was obeyed over the range 0{approx}20 {mu}g of boron in 25 mL of solution. The biological assays indicate the PGLD-B with boron-10 concentration of 25 mg{sup 10}B/gPGLD as the most promising macromolecule enriched with boron-10 for the BNCT therapy. (author)

  12. Boron carbide as a target for the SPES project

    International Nuclear Information System (INIS)

    Corradetti, S.; Carturan, S.; Biasetto, L.; Andrighetto, A.; Colombo, P.

    2013-01-01

    Within the framework of the research on targets for the SPES project (Selective Production of Exotic Species), porous boron carbide (B 4 C) based materials were produced from the carbothermal reduction of boric acid and two different carbon sources, i.e. citric acid and phenolic resin. Samples composition and microstructural morphology were studied by means of X-ray diffraction spectrometry (XRD) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM–EDS). The amount of total porosity was obtained from the comparison between the theoretical density and the measured bulk density. To better characterize the material microstructure, nitrogen physisorption measurements were performed in order to obtain data about the type of generated porosity and the specific surface area of the samples. Analysis performed on the samples show that after the final thermal treatment they are composed of boron carbide and residual free carbon, whose quantity is related to the processes involved in the two synthesis. Remarkable differences in the overall weight loss have been noticed for the two different reactions, resulting in different densities and pore size distributions, but in both cases similar values of specific surface area (SSA) were obtained.

  13. Boron-10 ABUNCL Prototype Models And Initial Active Testing

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Siciliano, Edward R.

    2013-04-23

    The Department of Energy Office of Nuclear Safeguards and Security (NA-241) is supporting the project Coincidence Counting With Boron-Based Alternative Neutron Detection Technology at Pacific Northwest National Laboratory (PNNL) for the development of a 3He proportional counter alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a system based upon 10B-lined proportional tubes in a configuration typical for 3He-based coincidence counter applications. This report provides results from MCNPX model simulations and initial testing of the active mode variation of the Alternative Boron-Based Uranium Neutron Coincidence Collar (ABUNCL) design built by General Electric Reuter-Stokes. Initial experimental testing of the as-delivered passive ABUNCL was previously reported.

  14. Boron/aluminum skins for the DC-10 aft pylon

    Science.gov (United States)

    Elliott, S. Y.

    1977-01-01

    Three boron/aluminum aft pylon 'boat tail' skins were designed, fabricated, and installed on three DC-10 aircraft for a five-year flight service demonstration test. Inspection and tests of the skins will establish the ability of the composite to withstand long-time flight service exposures to high temperatures, sonic fatigue, and flutter. The results of a preliminary testing program yielded room and elevated temperature data on the tension, compression, in-plane shear, interlaminar shear, bolt bearing, and tension fatigue properties of the oriented eleven-ply boron/aluminum laminates, and this information, together with a stress analysis, was used to obtain Federal Aviation Administration approval. Present state-of-the-art technology was used in the fabrication of the skins, and these were installed on the existing titanium substructure with the same number and size mechanical fasteners as are used for the present titanium skins.

  15. Boron containing magnetic nanoparticles for neutron capture therapy – an innovative approach for specifically targeting tumors

    International Nuclear Information System (INIS)

    Tietze, Rainer; Unterweger, Harald; Dürr, Stephan; Lyer, Stefan; Canella, Lea; Kudejova, Petra; Wagner, Franz M.; Petry, Winfried; Taccardi, Nicola; Alexiou, Christoph

    2015-01-01

    The selective delivery of 10 B into the tumor tissue remains to be further improved for successful and reliable Boron Neutron Capture Therapy applications. Magnetic Drug Targeting using intraarterially administered superparamagnetic nanoparticles and external magnetic fields already exhibited convincing results in terms of highly efficient and selective drug deposition. Using the same technique for the targeted 10 B delivery is a promising new approach. Here, systematic irradiation experiments of phantom cubes containing different concentrations of boron and nanoparticles as well as varying three-dimensional arrangements have been performed. - Highlights: • Magnetic Drug Targeting is a possible approach to substantially improve BNCT. • SPIONs did not influence the radiation dose deposition. • Superior dose deposition in gel phantoms reflecting Magnetic Drug Targeting set up.

  16. Double helix boron-10 powder thermal neutron detector

    Science.gov (United States)

    Wang, Zhehui; Morris, Christopher L.; Bacon, Jeffrey D.

    2015-06-02

    A double-helix Boron-10 powder detector having intrinsic thermal neutron detection efficiency comparable to 36'' long, 2-in diameter, 2-bar Helium-3 detectors, and which can be used to replace such detectors for use in portal monitoring, is described. An embodiment of the detector includes a metallic plate coated with Boron-10 powder for generating alpha and Lithium-7 particles responsive to neutrons impinging thereon supported by insulators affixed to at least two opposing edges; a grounded first wire wound in a helical manner around two opposing insulators; and a second wire having a smaller diameter than that of the first wire, wound in a helical manner around the same insulators and spaced apart from the first wire, the second wire being positively biased. A gas, disposed within a gas-tight container enclosing the plate, insulators and wires, and capable of stopping alpha and Lithium-7 particles and generating electrons produces a signal on the second wire which is detected and subsequently related to the number of neutrons impinging on the plate.

  17. 1H and 10B NMR and MRI investigation of boron- and gadolinium–boron compounds in boron neutron capture therapy

    International Nuclear Information System (INIS)

    Bonora, M.; Corti, M.; Borsa, F.; Bortolussi, S.; Protti, N.; Santoro, D.; Stella, S.; Altieri, S.; Zonta, C.; Clerici, A.M.; Cansolino, L.; Ferrari, C.; Dionigi, P.; Porta, A.; Zanoni, G.; Vidari, G.

    2011-01-01

    10 B molecular compounds suitable for Boron Neutron Capture Therapy (BNCT) are tagged with a Gd(III) paramagnetic ion. The newly synthesized molecule, Gd-BPA, is investigated as contrast agent in Magnetic Resonance Imaging (MRI) with the final aim of mapping the boron distribution in tissues. Preliminary Nuclear Magnetic Resonance (NMR) measurements, which include 1 H and 10 B relaxometry in animal tissues, proton relaxivity of the paramagnetic Gd-BPA molecule in water and its absorption in tumoral living cells, are reported.

  18. 1H and 10B NMR and MRI investigation of boron- and gadolinium-boron compounds in boron neutron capture therapy.

    Science.gov (United States)

    Bonora, M; Corti, M; Borsa, F; Bortolussi, S; Protti, N; Santoro, D; Stella, S; Altieri, S; Zonta, C; Clerici, A M; Cansolino, L; Ferrari, C; Dionigi, P; Porta, A; Zanoni, G; Vidari, G

    2011-12-01

    (10)B molecular compounds suitable for Boron Neutron Capture Therapy (BNCT) are tagged with a Gd(III) paramagnetic ion. The newly synthesized molecule, Gd-BPA, is investigated as contrast agent in Magnetic Resonance Imaging (MRI) with the final aim of mapping the boron distribution in tissues. Preliminary Nuclear Magnetic Resonance (NMR) measurements, which include (1)H and (10)B relaxometry in animal tissues, proton relaxivity of the paramagnetic Gd-BPA molecule in water and its absorption in tumoral living cells, are reported. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Evidence for multiple polytypes of semiconducting boron carbide (C2B10) from electronic structure

    International Nuclear Information System (INIS)

    Lunca-Popa, Petru; Brand, J I; Balaz, Snjezana; Rosa, Luis G; Boag, N M; Bai Mengjun; Robertson, B W; Dowben, P A

    2005-01-01

    Boron carbides fabricated via plasma enhanced chemical vapour deposition from different isomeric source compounds with the same C 2 B 10 H 12 closo-icosahedral structure result in materials with very different direct (optical) band gaps. This provides compelling evidence for the existence of multiple polytypes of C 2 B 10 boron carbide and is consistent with electron diffraction results

  20. Boron Stress Responsive MicroRNAs and Their Targets in Barley

    Science.gov (United States)

    Ozhuner, Esma; Eldem, Vahap; Ipek, Arif; Okay, Sezer; Sakcali, Serdal; Zhang, Baohong; Boke, Hatice; Unver, Turgay

    2013-01-01

    Boron stress is an environmental factor affecting plant development and production. Recently, microRNAs (miRNAs) have been found to be involved in several plant processes such as growth regulation and stress responses. In this study, miRNAs associated with boron stress were identified and characterized in barley. miRNA profiles were also comparatively analyzed between root and leave samples. A total of 31 known and 3 new miRNAs were identified in barley; 25 of them were found to respond to boron treatment. Several miRNAs were expressed in a tissue specific manner; for example, miR156d, miR171a, miR397, and miR444a were only detected in leaves. Additionally, a total of 934 barley transcripts were found to be specifically targeted and degraded by miRNAs. In silico analysis of miRNA target genes demonstrated that many miRNA targets are conserved transcription factors such as Squamosa promoter-binding protein, Auxin response factor (ARF), and the MYB transcription factor family. A majority of these targets were responsible for plant growth and response to environmental changes. We also propose that some of the miRNAs in barley such as miRNA408 might play critical roles against boron exposure. In conclusion, barley may use several pathways and cellular processes targeted by miRNAs to cope with boron stress. PMID:23555702

  1. High lateral resolution, quantitative SIMS analysis of boron-10 in rat brain tissue

    International Nuclear Information System (INIS)

    Oyedepo, A.C.; Heard, P.J.; Allen, G.C.; Brooke, S.L.; Patel, H.

    2000-01-01

    A SIMS (Secondary Ion Mass Spectroscopy) instrument providing high-resolution imaging has been used to examine the relative amounts of boron-10 ( 10 B) taken up in tumour and normal areas of rat brain tissue. It was possible to identify regions of low and high 10 B concentrations. The information is useful to the advancement of BNCT (Boron Neutron Capture Therapy) clinical trials. (author)

  2. Design, development and characterization of multi-functionalized gold nanoparticles for biodetection and targeted boron delivery in BNCT applications.

    NARCIS (Netherlands)

    Mandal, S.; Bakeine, G.J.; Krol, S.; Ferrari, C.; Clerici, A.M.; Zonta, C.; Cansolino, L.; Ballarini, F.; Bortolussi, S.; Stella, S.; Protti, N.; Bruschi, P.; Altieri, S.

    2011-01-01

    The aim of this study is to optimize targeted boron delivery to cancer cells and its tracking down to the cellular level. To this end, we describe the design and synthesis of novel nanovectors that double as targeted boron delivery agents and fluorescent imaging probes. Gold nanoparticles were

  3. Total boron assessment in soil samples from dry Mediterranean region using the thick target-particle induced gamma-ray emission technique

    Energy Technology Data Exchange (ETDEWEB)

    Nsouli, B. [IBA Laboratory, Lebanese Atomic Energy Commission, National Council for Scientific Research, P.O. Box 11, 8281 Beirut (Lebanon)]. E-mail: bnsouli@cnrs.edu.lb; Darwish, T. [National Center for Remote Sensing, National Council for Scientific Research, P.O. Box 11, 8281 Beirut (Lebanon); Zahraman, K. [IBA Laboratory, Lebanese Atomic Energy Commission, National Council for Scientific Research, P.O. Box 11, 8281 Beirut (Lebanon); Bejjani, A. [IBA Laboratory, Lebanese Atomic Energy Commission, National Council for Scientific Research, P.O. Box 11, 8281 Beirut (Lebanon); Roumie, M. [IBA Laboratory, Lebanese Atomic Energy Commission, National Council for Scientific Research, P.O. Box 11, 8281 Beirut (Lebanon); Thomas, J.P. [Institut de Physique Nucleaire de Lyon, Universite Claude Bernard Lyon 1, 43 Bd. 11 novembre 1918, 69622 Villeurbanne Cedex (France)

    2006-08-15

    Among other trace elements, boron assessment in soils is important for assessing land quality in accordance with international criteria for landuse planning. In this paper the total boron concentrations, for more than 100 soil samples from one of the most important agricultural region in Lebanon (i.e. Akkar plain in the North), have been measured by the TT-PIGE technique using a proton beam. The specific boron gamma ray at 429 keV produced via the {sup 10}B(p, {alpha}{gamma}){sup 7}Be nuclear reaction was used. Results are presented and discussed in relation to the lithological classes of the studied area. Furthermore, the method validation, for boron quantification in thick target soil samples using the TT-PIGE technique, employing external standards and using the so-called E {sub 1/2} analytical approach, is highlighted and discussed.

  4. Introduction to Neutron Coincidence Counter Design Based on Boron-10

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Siciliano, Edward R.

    2012-01-22

    The Department of Energy Office of Nonproliferation Policy (NA-241) is supporting the project 'Coincidence Counting With Boron-Based Alternative Neutron Detection Technology' at Pacific Northwest National Laboratory (PNNL) for development of an alternative neutron coincidence counter. The goal of this project is ultimately to design, build and demonstrate a boron-lined proportional tube based alternative system in the configuration of a coincidence counter. This report, providing background information for this project, is the deliverable under Task 1 of the project.

  5. High-power liquid-lithium target prototype for accelerator-based boron neutron capture therapy.

    Science.gov (United States)

    Halfon, S; Paul, M; Arenshtam, A; Berkovits, D; Bisyakoev, M; Eliyahu, I; Feinberg, G; Hazenshprung, N; Kijel, D; Nagler, A; Silverman, I

    2011-12-01

    A prototype of a compact Liquid-Lithium Target (LiLiT), which will possibly constitute an accelerator-based intense neutron source for Boron Neutron Capture Therapy (BNCT) in hospitals, was built. The LiLiT setup is presently being commissioned at Soreq Nuclear Research Center (SNRC). The liquid-lithium target will produce neutrons through the (7)Li(p,n)(7)Be reaction and it will overcome the major problem of removing the thermal power generated using a high-intensity proton beam (>10 kW), necessary for sufficient neutron flux. In off-line circulation tests, the liquid-lithium loop generated a stable lithium jet at high velocity, on a concave supporting wall; the concept will first be tested using a high-power electron beam impinging on the lithium jet. High intensity proton beam irradiation (1.91-2.5 MeV, 2-4 mA) will take place at Soreq Applied Research Accelerator Facility (SARAF) superconducting linear accelerator currently in construction at SNRC. Radiological risks due to the (7)Be produced in the reaction were studied and will be handled through a proper design, including a cold trap and appropriate shielding. A moderator/reflector assembly is planned according to a Monte Carlo simulation, to create a neutron spectrum and intensity maximally effective to the treatment and to reduce prompt gamma radiation dose risks. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. {sup 10}B uptake by cells for boron neutron capture synovectomy

    Energy Technology Data Exchange (ETDEWEB)

    Binello, E.; Yanch, J.C. [MIT, Department of Nuclear Engineering, Cambridge, MA (United States); Shortkroff, S. [Brigham and Women' s Hospital, Department of Orthopedic Surgery, Boston, MA (United States)

    2000-10-01

    Boron Neutron Capture Synovectomy (BNCS) proposes to use the {sup 10}B(n,{alpha}){sup 7}Li reaction to ablate inflamed synovium (a tissue lining articular joints) in patients with Rheumatoid Arthritis. Boron uptake is an important parameter for treatment design. In this study, a simple method was developed to determine K{sub 2}B{sub 12}H{sub 12} (KBH) uptake in vitro by non-adhering monocytic cells (representative of synovial cells in inflamed joints). Uptake was quantified as a function of incubation time and boron concentration, as well as following washout: no significant difference was found between incubation times tested; average uptake ranged from 55 to 60% of {sup 10}B incubation concentrations varying from 1000 to 5000 ppm: approximately 15% of the {sup 10}B concentration was measured upon re-incubation in boron-free medium. These results agree well with those obtained ex vivo using human arthritic synovium, a significant finding in light of the difficulty typically associated with obtaining such tissue. The full characterization of {sup 10}B uptake for BNCS (with KBH) is discussed. (author)

  7. Equilibrium charge state distributions for boron and carbon ions emerging from carbon and aluminum targets

    International Nuclear Information System (INIS)

    Schmitt, Chris; LaVerne, Jay A.; Robertson, Daniel; Bowers, Matthew; Lu Wenting; Collon, Philippe

    2010-01-01

    Equilibrium charge state distributions of boron and carbon ions through carbon and aluminum targets were measured with an energy range of 3-6 MeV. Comparisons of the data with relevant semi-empirical models for the equilibrium mean charge states and for the charge state distribution widths could provide valuable insight on the underlying mechanisms for a fast ion to lose or capture electrons. In-depth examinations of the experimental results in combination with semi-empirical models suggest that equilibrium charge state distributions are well represented by Gaussian distributions.

  8. In vitro induction of chromosomal aberrations in human lymphocytes, with and without boron 10, by radiations concerned in boron neutron capture therapy.

    Science.gov (United States)

    Lloyd, D C; Edwards, A A; Prosser, J S; Finnon, P; Moquet, J E

    1988-12-01

    A beam consisting of mainly 24 keV neutrons has been constructed for radiobiological studies to evaluate the potential of these particles for treating deep tumours by the boron capture reaction. The induction of chromosomal aberrations in human lymphocytes in vitro was examined and a linear dose effect with a relative biological effectiveness similar to fission neutrons was obtained. For samples placed at depths in a plastic phantom the aberration yields declined with depth at a rate matching the fall in the sum of dose due to proton recoils and neutron capture in nitrogen 14. The presence of boron 10 at 30 micrograms ml-1 did not affect the aberration yield. By using the mixed sample method, the probability of interphase death or mitotic delay in cells crossed by an alpha particle or lithium-7 ion produced in the boron capture reaction was shown to be close to 1.0. Thus these cells are prevented from coming to mitosis in culture. The implications for boron capture therapy are that this filtered beam has a "high LET" effect which could lead to poor normal tissue sparing. However there may be a significant therapeutic advantage due to a high probability of killing tumour cells that have incorporated boron 10.

  9. Use of inductively coupled plasma-mass spectrometry in boron-10 stable isotope experiments with plants, rats, and humans.

    Science.gov (United States)

    Vanderpool, R A; Hoff, D; Johnson, P E

    1994-11-01

    The commercial availability of inductively coupled plasma-mass spectrometry technology (ICP-MS) has presented the opportunity to measure the boron concentrations and isotope ratios in a large number of samples with minimal sample preparation. A typical analytical sequence for fecal samples consists of 25 acid blanks, 1 digestion blank, 5 calibration solutions, 4 standard reference material solutions, 10 samples, and 4 natural abundance bias standards. Boron detection limits (3 x 1 sigma) for acid blanks are 0.11 ppb for 10B, and 0.40 ppb for 11B. Isotope ratios were measured in fecal samples with 20 to 50 ppb boron with sample had a 1.0 ppb boron memory after a 6-min washout. Boron isotope ratios in geological materials are highly variable; apparently this variability is reflected in plants of a fixed natural abundance value for boron requires that a natural abundance ratio be determined for each sample or related data set. The natural abundance variability also prevents quantitation and calculation of isotope dilution by instrument-supplied software. To measure boron transport in animal systems, 20 micrograms of 10B were fed to a fasted rat. During the 3 days after a 10B oral dose, 95% of the 10B was recovered from the urine and 4% from the feces. Urinary isotope ratios, 11B/10B, changed from a natural abundance of 4.1140 to an enriched value of 0.95077, a 77% change.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Folate-conjugated boron nitride nanospheres for targeted delivery of anticancer drug

    Directory of Open Access Journals (Sweden)

    Feng S

    2016-09-01

    Full Text Available Shini Feng,1 Huijie Zhang,1 Ting Yan,1 Dandi Huang,1 Chunyi Zhi,2 Hideki Nakanishi,1 Xiao-Dong Gao1 1Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, People’s Republic of China; 2Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, People’s Republic of China Abstract: With its unique physical and chemical properties and structural similarity to carbon, boron nitride (BN has attracted considerable attention and found many applications. Biomedical applications of BN have recently started to emerge, raising great hopes in drug and gene delivery. Here, we developed a targeted anticancer drug delivery system based on folate-conjugated BN nanospheres (BNNS with receptor-mediated targeting. Folic acid (FA was successfully grafted onto BNNS via esterification reaction. In vitro cytotoxicity assay showed that BNNS-FA complexes were non-toxic to HeLa cells up to a concentration of 100 µg/mL. Then, doxorubicin hydrochloride (DOX, a commonly used anticancer drug, was loaded onto BNNS-FA complexes. BNNS-FA/DOX complexes were stable at pH 7.4 but effectively released DOX at pH 5.0, which exhibited a pH sensitive and sustained release pattern. BNNS-FA/DOX complexes could be recognized and specifically internalized by HeLa cells via FA receptor-mediated endocytosis. BNNS-FA/DOX complexes exhibited greater cytotoxicity to HeLa cells than free DOX and BNNS/DOX complexes due to the increased cellular uptake of DOX mediated by the FA receptor. Therefore, BNNS-FA complexes had strong potential for targeted cancer therapy. Keywords: boron nitride nanospheres, folic acid, doxorubicin, targeted delivery, cancer therapy

  11. Boronic acid-tethered amphiphilic hyaluronic acid derivative-based nanoassemblies for tumor targeting and penetration.

    Science.gov (United States)

    Jeong, Jae Young; Hong, Eun-Hye; Lee, Song Yi; Lee, Jae-Young; Song, Jae-Hyoung; Ko, Seung-Hak; Shim, Jae-Seong; Choe, Sunghwa; Kim, Dae-Duk; Ko, Hyun-Jeong; Cho, Hyun-Jong

    2017-04-15

    (3-Aminomethylphenyl)boronic acid (AMPB)-installed hyaluronic acid-ceramide (HACE)-based nanoparticles (NPs), including manassantin B (MB), were fabricated for tumor-targeted delivery. The amine group of AMPB was conjugated to the carboxylic acid group of hyaluronic acid (HA) via amide bond formation, and synthesis was confirmed by spectroscopic methods. HACE-AMPB/MB NPs with a 239-nm mean diameter, narrow size distribution, negative zeta potential, and >90% drug encapsulation efficiency were fabricated. Exposed AMPB in the outer surface of HACE-AMPB NPs (in the aqueous environment) may react with sialic acid of cancer cells. The improved cellular accumulation efficiency, in vitro antitumor efficacy, and tumor penetration efficiency of HACE-AMPB/MB NPs, compared with HACE/MB NPs, in MDA-MB-231 cells (CD44 receptor-positive human breast adenocarcinoma cells) may be based on the CD44 receptor-mediated endocytosis and phenylboronic acid-sialic acid interaction. Enhanced in vivo tumor targetability, infiltration efficiency, and antitumor efficacies of HACE-AMPB NPs, compared with HACE NPs, were observed in a MDA-MB-231 tumor-xenografted mouse model. In addition to passive tumor targeting (based on an enhanced permeability and retention effect) and active tumor targeting (interaction between HA and CD44 receptor), the phenylboronic acid-sialic acid interaction can play important roles in augmented tumor targeting and penetration of HACE-AMPB NPs. STATEMENT OF SIGNIFICANCE: (3-Aminomethylphenyl)boronic acid (AMPB)-tethered hyaluronic acid-ceramide (HACE)-based nanoparticles (NPs), including manassantin B (MB), were fabricated and their tumor targeting and penetration efficiencies were assessed in MDA-MB-231 (CD44 receptor-positive human adenocarcinoma) tumor models. MB, which exhibited antitumor efficacies via the inhibition of angiogenesis and hypoxia inducible factor (HIF)-1, was entrapped in HACE-AMPB NPs in this study. Phenylboronic acid located in the outer surface

  12. Boron reclamation

    International Nuclear Information System (INIS)

    Smith, R.M.

    1980-07-01

    A process to recover high purity 10 B enriched crystalline boron powder from a polymeric matrix was developed on a laboratory basis and ultimately scaled up to production capacity. The process is based on controlled pyrolysis of boron-filled scrap followed by an acid leach and dry sieving operation to return the powder to the required purity and particle size specifications. Typically, the recovery rate of the crystalline powder is in excess of 98.5 percent, and some of the remaining boron is recovered in the form of boric acid. The minimum purity requirement of the recovered product is 98.6 percent total boron

  13. Catalytic growth of vertically aligned neutron sensitive {sup 10}Boron nitride nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Pervaiz, E-mail: pervaizahmad@siswa.um.edu.my, E-mail: Pervaiz-pas@yahoo.com; Khandaker, Mayeen Uddin, E-mail: mu-khandaker@yahoo.com, E-mail: mu-khandaker@um.edu.my; Amin, Yusoff Mohd [University of Malaya, Department of Physics, Faculty of Science (Malaysia); Khan, Ghulamullah [University of Malaya, Department of Mechanical Engineering (Malaysia); Ramay, Shahid M. [King Saud University, Department of Physics and Astronomy, College of Science (Saudi Arabia); Mahmood, Asif [King Saud University, Department of Chemical Engineering, College of Engineering (Saudi Arabia); Amin, Muhammad [University of the Punjab, Department of Physics (Pakistan); Muhammad, Nawshad [Interdisciplinary Research Centre in Biomedical Materials (IRCBM) COMSATS Institute of Information Technology (Pakistan)

    2016-01-15

    {sup 10}Boron nitride nanotubes ({sup 10}BNNTs) are a potential neutron sensing element in a solid-state neutron detector. The aligned {sup 10}BNNT can be used for its potential application without any further purification. Argon-supported thermal CVD is used to achieve vertically aligned {sup 10}BNNT with the help of nucleation sites produced in a thin layer of magnesium–iron alloy deposited at the top of Si substrate. FESEM shows vertically aligned {sup 10}BNNTs with ball-like catalytic tips at top. EDX reveals magnesium (Mg) contents in the tips that refer to catalytic growth of {sup 10}BNNT. HR-TEM shows tubular morphology of the synthesized {sup 10}BNNT with lattice fringes on its outer part having an interlayer spacing of ∼0.34 nm. XPS shows B 1 s and N 1 s peaks at 190.5 and 398 eV that correspond to hexagonal {sup 10}Boron nitride ({sup 10}h-BN) nature of the synthesized {sup 10}BNNT, whereas the Mg kll auger peaks at ∼301 and ∼311 eV represents Mg contents in the sample. Raman spectrum has a peak at 1390 (cm{sup −1}) that corresponds to E{sub 2g} mode of vibration in {sup 10}h-BN.

  14. Targeted and non-targeted boron complex formation followed by electrospray Fourier transform ion cyclotron mass spectrometry: a novel approach for identifying boron esters with natural organic matter.

    Science.gov (United States)

    Gaspar, Andras; Lucio, Marianna; Harir, Mourad; Schmitt-Kopplin, Philippe

    2011-01-01

    The formation of boron esters was investigated in peat-soluble humified materials with a detailed molecular-level description of boron-organic interactions. Thousands of individually baseline separated signals were obtained from the analysis of natural organic matter of peat samples, using Fourier transform ion cyclotron resonance mass spectrometry. This technique offers unsurpassed isotope-specific mass resolution that can lead to precise molecular formula assignments by means of mathematical data analysis and visualisation techniques, such as mass defect (Kendrick) or elemental ratio (van Krevelen) plots. The analysis of potential boron binding structures within the sample of natural organic matter was described based on prior results. Herein, we describe an algorithm that can be used to effectively distinguish and filter complexes through data obtained from boron-enriched systems with highly intricate mass spectra, such as natural organic matter.

  15. 100-nm thick single-phase wurtzite BAlN films with boron contents over 10%

    KAUST Repository

    Li, Xiaohang

    2017-01-11

    Growing thicker BAlN films while maintaining single-phase wurtzite structure and boron content over 10% has been challenging. In this study, we report on the growth of 100 nm-thick single-phase wurtzite BAlN films with boron contents up to 14.4% by MOCVD. Flow-modulated epitaxy was employed to increase diffusion length of group-III atoms and reduce parasitic reactions between the metalorganics and NH3. A large growth efficiency of ∼2000 μm mol−1 was achieved as a result. Small B/III ratios up to 17% in conjunction with high temperatures up to 1010 °C were utilized to prevent formation of the cubic phase and maintain wurtzite structure.

  16. Use of inductively coupled plasma-mass spectrometry in boron-10 stable isotope experiments with plants, rats, and humans.

    Science.gov (United States)

    Vanderpool, R A; Hoff, D; Johnson, P E

    1994-01-01

    The commercial availability of inductively coupled plasma-mass spectrometry technology (ICP-MS) has presented the opportunity to measure the boron concentrations and isotope ratios in a large number of samples with minimal sample preparation. A typical analytical sequence for fecal samples consists of 25 acid blanks, 1 digestion blank, 5 calibration solutions, 4 standard reference material solutions, 10 samples, and 4 natural abundance bias standards. Boron detection limits (3 x 1 sigma) for acid blanks are 0.11 ppb for 10B, and 0.40 ppb for 11B. Isotope ratios were measured in fecal samples with 20 to 50 ppb boron with boron biological sample had a 1.0 ppb boron memory after a 6-min washout. Boron isotope ratios in geological materials are highly variable; apparently this variability is reflected in plants of a fixed natural abundance value for boron requires that a natural abundance ratio be determined for each sample or related data set. The natural abundance variability also prevents quantitation and calculation of isotope dilution by instrument-supplied software. To measure boron transport in animal systems, 20 micrograms of 10B were fed to a fasted rat. During the 3 days after a 10B oral dose, 95% of the 10B was recovered from the urine and 4% from the feces. Urinary isotope ratios, 11B/10B, changed from a natural abundance of 4.1140 to an enriched value of 0.95077, a 77% change.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7889873

  17. Analysis of oxygen concentration in boron target and study of CPAA

    International Nuclear Information System (INIS)

    Liu Guangzhi; Tang Guoyou; Chen Jinxiang; Wu Jun; Zhang Guohui; Zhang Yong

    1999-09-01

    Using Charged Particle Activation Analysis (CPAA), the concentration of oxygen in a thin boron target was determined, and the method of analyzing the thin unknown sample in comparison with the thick standard was studied. 3 He particles were accelerated to 8.0 MeV energy by 4.5 MV Van de Graaff accelerator to irradiate the isotope 16 O in samples and the artificial radioisotope 18 F was created by the reaction 16 O( 3 He, p) 18 F. The β + radioactivity of 18 F was measured by the high resolution gamma-ray spectroscopy. By comparing the radioactivity of the sample and the standard, the concentration of isotope 16 O was determined

  18. Medicinal electronomics bricolage design of hypoxia-targeting antineoplastic drugs and invention of boron tracedrugs as innovative future-architectural drugs.

    Science.gov (United States)

    Hori, Hitoshi; Uto, Yoshihiro; Nakata, Eiji

    2010-09-01

    We describe herein for the first time our medicinal electronomics bricolage design of hypoxia-targeting antineoplastic drugs and boron tracedrugs as newly emerging drug classes. A new area of antineoplastic drugs and treatments has recently focused on neoplastic cells of the tumor environment/microenvironment involving accessory cells. This tumor hypoxic environment is now considered as a major factor that influences not only the response to antineoplastic therapies but also the potential for malignant progression and metastasis. We review our medicinal electronomics bricolage design of hypoxia-targeting drugs, antiangiogenic hypoxic cell radiosensitizers, sugar-hybrid hypoxic cell radiosensitizers, and hypoxia-targeting 10B delivery agents, in which we design drug candidates based on their electronic structures obtained by molecular orbital calculations, not based solely on pharmacophore development. These drugs include an antiangiogenic hypoxic cell radiosensitizer TX-2036, a sugar-hybrid hypoxic cell radiosensitizer TX-2244, new hypoxia-targeting indoleamine 2,3-dioxygenase (IDO) inhibitors, and a hypoxia-targeting BNCT agent, BSH (sodium borocaptate-10B)-hypoxic cytotoxin tirapazamine (TPZ) hybrid drug TX-2100. We then discuss the concept of boron tracedrugs as a new drug class having broad potential in many areas.

  19. Intracellular targeting of mercaptoundecahydrododecaborate (BSH) to malignant glioma by transferrin-PEG liposomes for boron neutron capture therapy (BNCT)

    International Nuclear Information System (INIS)

    Doi, Atsushi; Miyatake, Shin-ichi; Iida, Kyouko

    2006-01-01

    Malignant glioma is one of the most difficult tumor to control with usual therapies. In our institute, we select boron neutron capture therapy (BNCT) as an adjuvant radiation therapy after surgical resection. This therapy requires the selective delivery of high concentration of 10 B to malignant tumor tissue. In this study, we focused on a tumor-targeting 10 B delivery system (BDS) for BNCT that uses transferrin-conjugated polyethylene-glycol liposome encapsulating BSH (TF-PEG liposome-BSH) and compared 10 B uptake of the tumor among BSH, PEG liposome-BSH and TF-PEG liposome-BSH. In vitro, we analyzed 10 B concentration of the cultured human U87Δ glioma cells incubated in medium containing 20 μg 10 B/ml derived from each BDS by inductively coupled plasma atomic emission spectrometry (ICP-AES). In vivo, human U87Δ glioma-bearing nude mice were administered with each BDS (35mg 10 B/kg) intravenously. We analyzed 10 B concentration of tumor, normal brain and blood by ICP-AES. The TF-PEG liposome-BSH showed higher absolute concentration more than the other BDS. Moreover, TF-PEG liposome-BSH decreased 10 B concentration in blood and normal tissue while it maintained high 10 B concentration in tumor tissue for a couple of days. This showed the TF-PEG liposome-BSH caused the selective delivery of high concentration of 10 B to malignant tumor tissue. The TF-PEG liposome-BSH is more potent BDS for BNCT to obtain absolute high 10 B concentration and good contrast between tumor and normal tissue than BSH and PEG liposome-BSH. (author)

  20. B sub 4 C solid target boronization of the MST reversed-field pinch

    Energy Technology Data Exchange (ETDEWEB)

    Den Hartog, D.J.; Cekic, M.; Fiksel, G.; Hokin, S.A.; Kendrick, R.D.; Prager, S.C.; Stoneking, M.R.

    1992-10-01

    A solid rod of hot-pressed boron carbide is being used as the source of boron during boronization of MST. The most striking result of this procedure is the reduction in oxygen contamination of the plasma (O III radiation, characteristic of oxygen at the edge, falls by about a factor of 3 after boronization.). The radiated power fraction drops to about half its initial value. Particle reflux from the wall is also lowered, making density control simpler. The rod (12.7 mm diameter) is inserted into the edge plasma of normal high-power RFP discharges. B{sub 4}C is ablated from the surface of the rod and deposited in a thin film (a-B/C:H) on the walls and limiters. The energy flux carried by superthermal'' (not runaway'') electrons at the edge of MST appears to enhance the efficient, non-destructive ablation of the boron carbide rod.

  1. B{sub 4}C solid target boronization of the MST reversed-field pinch

    Energy Technology Data Exchange (ETDEWEB)

    Den Hartog, D.J.; Cekic, M.; Fiksel, G.; Hokin, S.A.; Kendrick, R.D.; Prager, S.C.; Stoneking, M.R.

    1992-10-01

    A solid rod of hot-pressed boron carbide is being used as the source of boron during boronization of MST. The most striking result of this procedure is the reduction in oxygen contamination of the plasma (O III radiation, characteristic of oxygen at the edge, falls by about a factor of 3 after boronization.). The radiated power fraction drops to about half its initial value. Particle reflux from the wall is also lowered, making density control simpler. The rod (12.7 mm diameter) is inserted into the edge plasma of normal high-power RFP discharges. B{sub 4}C is ablated from the surface of the rod and deposited in a thin film (a-B/C:H) on the walls and limiters. The energy flux carried by ``superthermal`` (not ``runaway``) electrons at the edge of MST appears to enhance the efficient, non-destructive ablation of the boron carbide rod.

  2. A simple and rapid method for measurement of 10B-para-boronophenylalanine in the blood for boron neutron capture therapy using fluorescence spectrophotometry

    International Nuclear Information System (INIS)

    Kashino, Genro; Fukutani, Satoshi; Suzuki, Minoru

    2009-01-01

    10 B deriving from 10 B-para-boronophenylalanine (BPA) and 10 B-borocaptate sodium (BSH) have been detected in blood samples of patients undergoing boron neutron capture therapy (BNCT) using prompt gamma ray spectrometer or Inductively Coupled Plasma (ICP) method, respectively. However, the concentration of each compound cannot be ascertained because boron atoms in both molecules are the target in these assays. Here, we propose a simple and rapid method to measure only BPA by detecting fluorescence based on the characteristics of phenylalanine. 10 B concentrations of blood samples from human or mice were estimated by the fluorescence intensities at 275 nm of a BPA excited by light of wavelength 257 nm using a fluorescence spectrophotometer. The relationship between fluorescence to increased BPA concentration showed a positive linear correlation. Moreover, we established an adequate condition for BPA measurement in blood samples containing BPA, and the estimated 10 B concentrations of blood samples derived from BPA treated mice were similar between the values obtained by our method and those by ICP method. This new assay will be useful to estimate BPA concentration in blood samples obtained from patients undergoing BNCT especially in a combination use of BSH and BPA. (author)

  3. Transferrin-loaded nido-carborane liposomes. Synthesis and intracellular targeting to solid tumors for boron neutron capture therapy

    International Nuclear Information System (INIS)

    Nakamura, Hiroyuki; Miyajima, Yusuke; Kuwata, Yasuhiro; Maruyama, Kazuo; Masunaga, Shinichiro; Ono, Koji

    2006-01-01

    The boron ion cluster lipids, as a double-tailed boron lipid synthesized from heptadecanol, formed stable liposomes at 25% molar ratio toward DSPC with cholesterol. Transferrin was able to be introduced on the surface of boron liposomes (Tf-PEG-CL liposomes) by the coupling of transferrin to the PEG-CO 2 H moieties of PEG-CL liposomes. The biodistribution of Tf-PEG-CL liposomes showed that Tf-PEG-CL liposomes accumulated in tumor tissues and stayed there for a sufficiently long time to increase tumor:blood concentration ratio. A 10 B concentration of 22 ppm in tumor tissues was achieved by the injection of Tf-PEG-CL liposome at 7.2 mg/kg body weight 10 B in tumor-bearing mice. After neutron irradiation, the average survival rate of mice not treated with Tf-PEG-CL liposomes was 21 days, whereas that of the treated mice was 31 days. Longer survival rates were observed in the mice treated with Tf-PEG-CL liposomes; one of them even survived for 52 days after BNCT. (author)

  4. Demonstration of a high-intensity neutron source based on a liquid-lithium target for Accelerator based Boron Neutron Capture Therapy.

    Science.gov (United States)

    Halfon, S; Arenshtam, A; Kijel, D; Paul, M; Weissman, L; Berkovits, D; Eliyahu, I; Feinberg, G; Kreisel, A; Mardor, I; Shimel, G; Shor, A; Silverman, I; Tessler, M

    2015-12-01

    A free surface liquid-lithium jet target is operating routinely at Soreq Applied Research Accelerator Facility (SARAF), bombarded with a ~1.91 MeV, ~1.2 mA continuous-wave narrow proton beam. The experiments demonstrate the liquid lithium target (LiLiT) capability to constitute an intense source of epithermal neutrons, for Accelerator based Boron Neutron Capture Therapy (BNCT). The target dissipates extremely high ion beam power densities (>3 kW/cm(2), >0.5 MW/cm(3)) for long periods of time, while maintaining stable conditions and localized residual activity. LiLiT generates ~3×10(10) n/s, which is more than one order of magnitude larger than conventional (7)Li(p,n)-based near threshold neutron sources. A shield and moderator assembly for BNCT, with LiLiT irradiated with protons at 1.91 MeV, was designed based on Monte Carlo (MCNP) simulations of BNCT-doses produced in a phantom. According to these simulations it was found that a ~15 mA near threshold proton current will apply the therapeutic doses in ~1h treatment duration. According to our present results, such high current beams can be dissipated in a liquid-lithium target, hence the target design is readily applicable for accelerator-based BNCT. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. 10

    Science.gov (United States)

    Sunitha, Y; Kumar, Sanjiv

    2017-10-01

    The 10 B/ 11 B isotopic ratio and the atomic composition of boron carbide, an important non-metallic ceramic, have been determined non-destructively by the particle induced γ-ray emission (PIGE) and elastic backscattering spectrometry (EBS) techniques with proton beams. The analysis has been performed on powder as well as sintered ceramics containing boron in natural or 10 B enriched composition. The PIGE technique, performed at a 4.0-4.2MeV proton energy, utilizes the 10 B(p,αγ) 7 Be, 10 B(p,p'γ) 10 B and 11 B(p, p'γ) 11 B nuclear reactions for (a) the isotopic analysis of boron and (b) the determination of total boron, and the 13 C(p,p'γ) 13 C nuclear reaction for the determination of carbon. The irradiation conditions were optimized by determining the thick targets yields of prompt γ-rays, characteristic of these reactions, in the 3.0-4.2MeV proton energy range. The quantitative analysis was performed by comparison with standards taking into account the attenuation of γ-rays in the specimens. The uncertainty in the determination of the 10 B/ 11 B isotopic ratio and the B/C atomic ratio is about 2% and about 5% respectively. The analysis by EBS, on the other hand, involves the 10 B(p,p) 10 B, 11 B(p,p) 11 B and 12 C(p,p) 12 C elastic scatterings at the 2.0MeV proton energy. This method too yields satisfactory results. Between the two, PIGE is the method of choice for bulk analysis while EBS is useful in discerning compositional variations in surface regions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Study of a neutron producing target via the 7Li(p,n)7Be reaction near its energy threshold for BNCT (boron neutron capture therapy)

    International Nuclear Information System (INIS)

    Burlon, Alejandro; Kreiner, Andres J.; Debray, Mario E.; Stoliar, Pablo; Kesque, Jose M.; Naab, Fabian; Ozafran, Mabel J.; Schuff, Juan; Vazquez, Monica; Caraballo, Maria E.; Valda, Alejandro; Somacal, Hector; Davidson, Miguel; Davidson, Jorge

    2000-01-01

    In the framework of Accelerator Based BNCT (AB-BNCT) the 7 Li(p,n) 7 Be reaction near its energy threshold is one of the most promising. In this work a thick LiF target irradiated with a proton beam was studied as a neutron source. The 1.88-2.0 MeV proton beam was produced by the tandem accelerator TANDAR at CNEA's facilities in Buenos Aires. A water-filled phantom, containing a boron sample was irradiated with the resulting neutron beam. The boron neutron capture reaction produces a 0.478 MeV gamma ray in 94 % of the cases. The neutron yield was monitored by detecting this gamma ray using a germanium detector with an 'anti-Compton' shield. Moreover, the thermal neutron flux was evaluated at different depths inside the phantom using bare and Cd-covered gold foils. A maximum neutron thermal flux of 1.4 x 10 8 1/(cm 2 -s-mA) was obtained at 4.2 cm from the phantom surface. (author)

  7. Preparation of new boron compounds with potential for application in 10B NCT: Derivatives of monocarbon carboranes

    International Nuclear Information System (INIS)

    Morris, J.H.; Khan, S.A.; Mair, F.; Peters, G.

    1992-01-01

    In order to extend the range and versatility of boron clusters appropriate to NCT the authors have studied routes to derivatives of the anions 1-carba-closo-dodecahydrododecaborate-1, [CB 11 H 12 ] - , (1), and its synthetic precursor, 7-carba-nido-tridecahydroundecaborate-1, [CB 10 H 13 ] - , (2). Substitution chemistry of closo-[CB 11 H 12 ] - and its derivatives had been examined previously primarily with respect to substituents at the C-atom. The different isomeric sites of boron substitution, which have been much less studied, offer potential scope for subtle modification of properties of the substituted species. They have sought to prepare thiol substituted derivatives analogous to the widely studied species [B 12 H 11 SH] 2- . The preliminary experiments to introduce the thiol substituent by routes analogous to those for the preparation of [B 12 H 11 SH] 2- or 1- and 2-[B 10 H 9 SH] 2- were unsuccessful. Therefore they considered routes involving prior substitution of either the precursor nido-[CB 10 H 13 ] - and its derivatives, or the monoboron species used for boron insertion

  8. LITHIUM-BERYLLIUM-BORON ISOTOPIC COMPOSITIONS IN METEORITIC HIBONITE: IMPLICATIONS FOR ORIGIN OF 10Be AND EARLY SOLAR SYSTEM IRRADIATION

    International Nuclear Information System (INIS)

    Liu, Ming-Chang; Nittler, Larry R.; Alexander, Conel M. O'D.; Lee, Typhoon

    2010-01-01

    NanoSIMS isotopic measurements of Li, Be, and B in individual hibonite grains extracted from the Murchison meteorite revealed that 10 B excesses correlate with the 9 Be/ 11 B ratios in 26 Al-free PLAty hibonite Crystals. From these data, an initial 10 Be/ 9 Be = (5.5 ± 1.6) x 10 -4 (2σ) and 10 B/ 11 B = 0.2508 ± 0.0015 can be inferred. On the other hand, chondritic boron isotopic compositions were found in 26 Al-bearing Spinel-HIBonite spherules, most likely due to contamination with normal boron. No 7 Li excesses due to 7 Be decay were observed. When combined with previously reported data, the new data yield the best defined 10 Be/ 9 Be = (5.3 ± 1.0) x 10 -4 (2σ) and 10 B/ 11 B = 0.2513 ± 0.0012 for PLACs. A comparison of this value and the best constrained 10 Be/ 9 Be = (8.8 ± 0.6) x 10 -4 in CV Ca-Al-rich inclusions supports a heterogeneous distribution of 10 Be and its protosolar irradiation origin. We consider two possible irradiation scenarios that could potentially lead to the observed Li-Be-B isotopic compositions in PLACs. Although in situ irradiation of solids with hibonite chemistry seems to provide the simplest explanation, more high quality data will be needed for quantitatively constraining the irradiation history.

  9. Boron compartmentation in roots of sunflower plants of different boron status: A study using the stable isotopes 10B and 11B adopting two independent approaches

    International Nuclear Information System (INIS)

    Pfeffer, H.; Dannel, F.; Roemheld, V.

    2001-01-01

    The intracellular compartmentation of boron (B) in roots of sunflower plants precultured with 100 μM B (high B) or 1 μM B (low B) was studied using two independent approaches. In the first approach, short-term efflux studies using the stable isotopes 11 B and 10 B were carried out. In roots of high B plants, the calculated concentrations of B (nmol g FW -1 ) were 52.6 in the cell wall, 7.5 in the vacuole, 27.1 in the cytosol and 48.0 in the free space. In roots of low B plants, the concentrations of B (nmol g FW -1 ) were 43.4 in the cell wall, 2.8 in the vacuole, 17.9 in the cytosol and almost zero in the free space. Although the B supply differed by a factor 100, the B concentrations in the cytosol and the vacuole of low B plants were 66 and 37% of the respective concentrations in high B plants. This suggests an additional role for B in plant metabolism, besides its function in the cell wall. In the second approach, root B pools (cell sap and water-insoluble residue) were determined for comparison, and found to be in good agreement with the results from the efflux study. (au)

  10. Monitoring of blood-10B concentration for boron neutron capture therapy using prompt gamma-ray analysis

    International Nuclear Information System (INIS)

    Raaijmakers, C.P.J.; Konijnenberg, M.W.; Dewit, L.; Mijnheer, B.J.; Haritz, D.; Huiskamp, R.; Philipp, K.; Siefert, A.; Stecher-Rasmussen, F.

    1995-01-01

    The aim of the present study was to monitor the blood- 10 B concentration of laboratory dogs receiving boron neutron capture therapy, in order to obtain optimal agreement between prescribed and actual dose. A prompt gamma-ray analysis system was developed for this purpose at the High Flux Reactor in Petten. The technique was compared with inductively coupled plasma-atomic emission spectrometry and showed good agreement. A substantial variation in 10 B clearance pattern after administration of borocaptate sodium was found between the different dogs. Consequently, the irradiation commencement was adjusted to the individually determined boron elimination curve. Mean blood- 10 B concentratios during irradiation of 25.8±2.2 μg/g (1 SD, n=18) and 49.3±5.3 μg/g (1 SD, n=17) were obtained for intended concentrations of 25 μg/g and 50 μg/g, respectively. These variations are a factor of two smaller than irradiations performed at a uniform post-infusion irradiation starting time. Such a careful bolld- 10 B monitoring procedure is a prerequisite for accurately obtaining such steep dose-response curves as observed during the dog study. (orig.)

  11. Selective boron accumulation in human ocular melanoma by 10B1-para-boronophenylalanine administration for neutron capture therapy

    International Nuclear Information System (INIS)

    Wadabayashi, Nobutoshi; Ichihashi, Masamitsu; Honda, Chihiro; Mishima, Yutaka.

    1994-01-01

    Malignant melanoma occurs not only in the skin but also in ocular tissues. Ocular melanoma located superficially as in conjunctiva can be treated successfully by BNCT. In the present study, we investigated 10 B dynamics in ocular melanoma and the surrounding normal tissues, to evaluate the possibility of applying BNCT to ocular melanoma. In three ocular melanoma patients, 10 B concentration in melanoma after administration of 10 B-BPA by oral or drip infusion ranged from 10.4 to 21.5 ppm. The boron concentrations in lens and vitreous body were lower than blood level, whereas higher than blood in sclera and palpebral skin. These results suggest that we can treat such a superficial melanoma lesions as conjunctival melanoma by BNCT using 10 B 1 -BPA. (author)

  12. Advances in analytical techniques for neutron capture therapy: thin layer chromatography matrix and track etch thin layer chromatography methods for boron-10 analysis

    International Nuclear Information System (INIS)

    Schremmer, J.M.; Noonan, D.J.

    1987-01-01

    A new track etch autoradiographic technique for quantitating boron-10 containing compounds used for neutron capture therapy is described. Instead of applying solutions of Cs2B12H11SH and its oxidation products directly to solid-state nuclear track detectors, diethylaminoethyl cellulose thin layer chromatography (TLC) plates are utilized as sample matrices. The plates are juxtaposed with Lexan polycarbonate detectors and irradiated in a beam of thermal neutrons. The detectors are then chemically etched, and the resultant tracks counted with an optoelectronic image analyzer. Sensitivity to boron-10 in solution reaches the 1 pg/microliter level, or 1 ppb. In heparinized blood samples, 100 pg boron-10/microliter are detected. This TLC matrix method has the advantage that sample plates can be reanalyzed under different reactor conditions to optimize detector response to the boron-10 carrier material. Track etch/TLC allows quantitation of the purity of boron neutron capture therapy compounds by utilizing the above method with TLC plates developed in solvent systems that resolve Cs2B12H11SH and its oxidative analogs. Detectors irradiated in juxtaposition to the thin layer chromatograms are chemically etched, and the tracks are counted in the sample lane from the origin of the plate to the solvent front. A graphic depiction of the number of tracks per field yields a quantitative analysis of compound purity

  13. Pilot clinical study of boron neutron capture therapy for recurrent hepatic cancer involving the intra-arterial injection of a (10)BSH-containing WOW emulsion.

    Science.gov (United States)

    Yanagie, Hironobu; Higashi, Syushi; Seguchi, Koji; Ikushima, Ichiro; Fujihara, Mituteru; Nonaka, Yasumasa; Oyama, Kazuyuki; Maruyama, Syoji; Hatae, Ryo; Suzuki, Minoru; Masunaga, Shin-ichiro; Kinashi, Tomoko; Sakurai, Yoshinori; Tanaka, Hiroki; Kondo, Natsuko; Narabayashi, Masaru; Kajiyama, Tetsuya; Maruhashi, Akira; Ono, Koji; Nakajima, Jun; Ono, Minoru; Takahashi, Hiroyuki; Eriguchi, Masazumi

    2014-06-01

    A 63-year-old man with multiple HCC in his left liver lobe was enrolled as the first patient in a pilot study of boron neutron capture therapy (BNCT) involving the selective intra-arterial infusion of a (10)BSH-containing water-in-oil-in-water emulsion ((10)BSH-WOW). The size of the tumorous region remained stable during the 3 months after the BNCT. No adverse effects of the BNCT were observed. The present results show that (10)BSH-WOW can be used as novel intra-arterial boron carriers during BNCT for HCC. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Structural characterization of electrodeposited boron

    Indian Academy of Sciences (India)

    mental phase contrast images and the diffraction pattern. Figure 3. (a) Bright field image of electrodeposited boron spec- imen showing a crystallite of size ∼10 × 5 nm; (b) phase contrast image of electrodeposited boron specimen showing a resolved la- ttice and (c) power spectrum of electrodeposited boron specimen.

  15. 10 CFR 39.55 - Tritium neutron generator target sources.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Tritium neutron generator target sources. 39.55 Section 39... Equipment § 39.55 Tritium neutron generator target sources. (a) Use of a tritium neutron generator target....77. (b) Use of a tritium neutron generator target source, containing quantities exceeding 1,110 GBg...

  16. Inverse-Frontal Chromatography studies on enrichment of Boron-10 using quaternery 4-vinylpyridine-divinylbenzene resin

    International Nuclear Information System (INIS)

    Bejawada, Venki; Mohapatra, C.; Rao, A.S.; Prasad, K.L.; Murthy, P.K.; Rao, A.K.; Singh, H.P.; Vithal, G.K.; Kumar, Sangita D.

    2014-01-01

    In order to enrich 10 B, band migration of boric acid-mannitol with hydrochloric acid solution was performed by inverse frontal chromatography on a porous, 25% crosslinked, 38% quaternized 4-vinylpyridine-divinylbenzene resin (py-resin). The work was initiated to replace the existing strong base anion exchange resin type-II (SBA-II) which is used in Boron Enrichment Plant (BEP) of heavy water plant Manuguru. Before its application in BEP, it is mandatory to evaluate py-resin for its performance. The studies showed that maximum of 40% 10 B enrichment observed after 13 m band movement and there was no further improvement, hence profile sampling carried out after 28 m. (author)

  17. A method to build an analytic model of the 10B(n,alpha)7Li reaction rate space distribution for boron neutron capture therapy (BNCT).

    Science.gov (United States)

    Morand, Josselin; Moss, Raymond; Hachem, Sabet; Sauerwein, Wolfgang

    2009-07-01

    This work provides the basis of a methodology to build a deterministic model for the spatial distribution of the (10)B(n,alpha)(7)Li reaction rate in boron neutron capture therapy (BNCT), as a function of space variables, boron concentration and beam incidence angle in homogeneous isotropic environments but also in different heterogeneous environments. Building the analytic function in a simple homogeneous environment with numerical methods leads to a mathematical formulation of the (10)B(n,alpha)(7)Li reactions rate.

  18. Dosimetric comparative analysis between 10 MV Megavoltage unidirectional beam and boron neutron capture therapy for brain tumors treatment

    International Nuclear Information System (INIS)

    Brandao, Samia F.; Campos, Tarcisio P.R.

    2011-01-01

    This paper present a comparative dosimetric analysis between boron neutron capture therapy and 10 MV megavoltage employed in brain tumor treatments, limited to a unidirectional beam. A computational phantom of a human head was developed to be used in computational simulations of the two protocols, conducted in MCNP5 code. This phantom represents several head's structures, mainly, the central nervous system and a tumor that represents a Glioblastoma Multiform - one of the most malignant and aggressive brain tumors. Absorbed and biological weighted dose rates and neutron fluency in the computational phantom were evaluated from the MCNP5 code. The biologically weighted dose rate to 10 MV megavoltage beam presented no specificity in deposited dose in tumor. The average total biologically weighted dose rate in tumor was 9.93E-04 RBE.Gy.h -1 /Mp.s -1 while in healthy tissue it was 8.67E-04 RBE.Gy.h -1 /Mp.s - 1. On the BNCT simulations the boron concentration was particularly relevant since the largest dose deposition happened in borate tissues. The average total biologically weighted dose rate in tumor was 3.66E-02 RBE.Gy.h -1 /Mp.s -1 while in healthy tissue it was 1.39E-03 RBE.Gy.h -1 /Mp.s -1 . In comparison to the 10 MV megavoltage beam, BNCT showed clearly a largest dose deposition in the tumor, on average, 37 times larger than in the megavoltage beam, while in healthy tissue that average was only 1,6 time larger in BNCT. (author)

  19. Determination of boron by ICP-AES in normal and malignant cells incubated 'in vitro' with fructose 10BPA

    International Nuclear Information System (INIS)

    Garavaglia, Ricardo N.; Farias, Silvia S.; Rodriguez, Ruben E.; Servant, Roberto E.; Liberman, Sara; Pisarev, Mario A.; Batistoni, Daniel A.

    1999-01-01

    This paper describes the development and optimization of methodology for total boron concentration in cell cultures coming from fixation and accumulation of this element by normal and malignant cells. On account of sample mass and low volume resulting from dilution, generally about 1 mL, a procedure for automatic injection of micro volumes was designed, developed and optimized. Iron interference was carefully studied. Linear calibration curves were obtained for 50 to 2500 ng B/mL range. Determination limits were 10 and 20 ng B/mL for B 249.772 nm and 249.677 nm, respectively. Repeatability, expressed as relative standard deviation was better than 5% for a 100 ng B/mL. Recovery of analyte added to real samples ranged between 95 and 103%. The method was applied to studies on F-98 cells (rat glioma) and normal glia in BNCT project frame. (author)

  20. Quantitative subcellular secondary ion mass spectrometry (SIMS) imaging of boron-10 and boron-11 isotopes in the same cell delivered by two combined BNCT drugs: in vitro studies on human glioblastoma T98G cells.

    Science.gov (United States)

    Chandra, Subhash; Lorey II, Daniel R; Smith, Duane R

    2002-06-01

    Ion microscopy was used for subcellular quantitative imaging of the isotopes 10B and 11B in the same cell to evaluate boron delivery using a mixture of two neutron capture therapy drugs, p-boronophenylalanine-fructose (BPA-F) and sodium borocaptate (BSH). The application of 10B-labeled BPA-F and 11B-labeled BSH allowed independent imaging of both 10B and 11B in the same cell using a CAMECA IMS-3f ion microscope. Mixed-drug treatments were compared to single-drug exposures given under identical conditions. 10BPA-F delivered 10B heterogeneously to T98G human glioblastoma cells, with a significantly reduced concentration in an organelle-rich perinuclear region. The intracellular distribution of 11B from 11BSH contrasted with that of the 10B from 10BPA-F, with 11B distributed nearly homogeneously throughout cells. The subcellular distributions of 10B and 11B were sustained in mixed-drug treatments and resembled their localizations after the single-drug treatments. In both single- and mixed-drug treatments, cellular levels of 10B from 10BPA-F nearly doubled between 1 h and 6 h, with a 3:1 intracellular to nutrient medium partitioning, while cellular levels of 11BSH remained essentially unchanged. The net effect of the combined treatment with 10BPA-F and 11BSH was an additive delivery of boron to cells. This study introduces a novel approach for checking potential synergistic, antagonistic or simple additive delivery of two mixed boronated compounds in cellular/subcellular compartments.

  1. In vivo prompt gamma neutron activation analysis for the screening of boron-10 distribution in a rabbit knee: a simulation study

    Science.gov (United States)

    Zhu, X.; Clackdoyle, R.; Shortkroff, S.; Yanch, J.

    2008-05-01

    Boron neutron capture synovectomy (BNCS) is under development as a potential treatment modality for rheumatoid arthritis (RA). RA is characterized by the inflammation of the synovium (the membrane lining articular joints), which leads to pain and a restricted range of motion. BNCS is a two-part procedure involving the injection of a boronated compound directly into the diseased joint followed by irradiation with a low-energy neutron beam. The neutron capture reactions taking place in the synovium deliver a local, high-linear energy transfer (LET) dose aimed at destroying the inflamed synovial membrane. For successful treatment via BNCS, a boron-labeled compound exhibiting both high synovial uptake and long retention time is necessary. Currently, the in vivo uptake behavior of potentially useful boronated compounds is evaluated in the knee joints of rabbits in which arthritis has been induced. This strategy involves the sacrifice and dissection of a large number of animals. An in vivo 10B screening approach is therefore under investigation with the goal of significantly reducing the number of animals needed for compound evaluation via dissection studies. The 'in vivo prompt gamma neutron activation analysis' (IVPGNAA) approach uses a narrow neutron beam to irradiate the knee from several angular positions following the intra-articular injection of a boronated compound whose uptake characteristics are unknown. A high-purity germanium detector collects the 478 keV gamma photons produced by the 10B capture reactions. The 10B distribution in the knee is then reconstructed by solving a system of simultaneous equations using a weighted least squares algorithm. To study the practical feasibility of IVPGNAA, simulation data were generated with the Monte Carlo N-particle transport code. The boron-containing region of a rabbit knee was partitioned into 8 compartments, and the 10B prompt gamma signals were tallied from 16 angular positions. Results demonstrate that for this

  2. In vivo prompt gamma neutron activation analysis for the screening of boron-10 distribution in a rabbit knee: a simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, X; Yanch, J [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA (United States); Clackdoyle, R [Laboratoire Hubert Curien, Mixed Research Unit (UMR) 5516, CNRS and Universite Jean Monnet, Saint Etienne (France); Shortkroff, S [Department of Orthopedic Surgery, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA (United States)

    2008-05-21

    Boron neutron capture synovectomy (BNCS) is under development as a potential treatment modality for rheumatoid arthritis (RA). RA is characterized by the inflammation of the synovium (the membrane lining articular joints), which leads to pain and a restricted range of motion. BNCS is a two-part procedure involving the injection of a boronated compound directly into the diseased joint followed by irradiation with a low-energy neutron beam. The neutron capture reactions taking place in the synovium deliver a local, high-linear energy transfer (LET) dose aimed at destroying the inflamed synovial membrane. For successful treatment via BNCS, a boron-labeled compound exhibiting both high synovial uptake and long retention time is necessary. Currently, the in vivo uptake behavior of potentially useful boronated compounds is evaluated in the knee joints of rabbits in which arthritis has been induced. This strategy involves the sacrifice and dissection of a large number of animals. An in vivo {sup 10}B screening approach is therefore under investigation with the goal of significantly reducing the number of animals needed for compound evaluation via dissection studies. The 'in vivo prompt gamma neutron activation analysis' (IVPGNAA) approach uses a narrow neutron beam to irradiate the knee from several angular positions following the intra-articular injection of a boronated compound whose uptake characteristics are unknown. A high-purity germanium detector collects the 478 keV gamma photons produced by the {sup 10}B capture reactions. The {sup 10}B distribution in the knee is then reconstructed by solving a system of simultaneous equations using a weighted least squares algorithm. To study the practical feasibility of IVPGNAA, simulation data were generated with the Monte Carlo N-particle transport code. The boron-containing region of a rabbit knee was partitioned into 8 compartments, and the {sup 10}B prompt gamma signals were tallied from 16 angular positions

  3. High power accelerator-based boron neutron capture with a liquid lithium target and new applications to treatment of infectious diseases

    Energy Technology Data Exchange (ETDEWEB)

    Halfon, S. [Soreq NRC, Yavne 81800 (Israel); Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel)], E-mail: halfon@phys.huji.ac.il; Paul, M. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Steinberg, D. [Biofilm Laboratory, Institute of Dental Sciences, Faculty of Dentistry, Hebrew University-Hadassah (Israel); Nagler, A.; Arenshtam, A.; Kijel, D. [Soreq NRC, Yavne 81800 (Israel); Polacheck, I. [Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Center (Israel); Srebnik, M. [Department of Medicinal Chemistry and Natural Products, School of Pharmacy, Hebrew University, Jerusalem 91120 (Israel)

    2009-07-15

    A new conceptual design for an accelerator-based boron neutron capture therapy (ABNCT) facility based on the high-current low-energy proton beam driven by the linear accelerator at SARAF (Soreq Applied Research Accelerator Facility) incident on a windowless forced-flow liquid-lithium target, is described. The liquid-lithium target, currently in construction at Soreq NRC, will produce a neutron field suitable for the BNCT treatment of deep-seated tumor tissues, through the reaction {sup 7}Li(p,n){sup 7}Be. The liquid-lithium target is designed to overcome the major problem of solid lithium targets, namely to sustain and dissipate the power deposited by the high-intensity proton beam. Together with diseases conventionally targeted by BNCT, we propose to study the application of our setup to a novel approach in treatment of diseases associated with bacterial infections and biofilms, e.g. inflammations on implants and prosthetic devices, cystic fibrosis, infectious kidney stones. Feasibility experiments evaluating the boron neutron capture effectiveness on bacteria annihilation are taking place at the Soreq nuclear reactor.

  4. High power accelerator-based boron neutron capture with a liquid lithium target and new applications to treatment of infectious diseases

    International Nuclear Information System (INIS)

    Halfon, S.; Paul, M.; Steinberg, D.; Nagler, A.; Arenshtam, A.; Kijel, D.; Polacheck, I.; Srebnik, M.

    2009-01-01

    A new conceptual design for an accelerator-based boron neutron capture therapy (ABNCT) facility based on the high-current low-energy proton beam driven by the linear accelerator at SARAF (Soreq Applied Research Accelerator Facility) incident on a windowless forced-flow liquid-lithium target, is described. The liquid-lithium target, currently in construction at Soreq NRC, will produce a neutron field suitable for the BNCT treatment of deep-seated tumor tissues, through the reaction 7 Li(p,n) 7 Be. The liquid-lithium target is designed to overcome the major problem of solid lithium targets, namely to sustain and dissipate the power deposited by the high-intensity proton beam. Together with diseases conventionally targeted by BNCT, we propose to study the application of our setup to a novel approach in treatment of diseases associated with bacterial infections and biofilms, e.g. inflammations on implants and prosthetic devices, cystic fibrosis, infectious kidney stones. Feasibility experiments evaluating the boron neutron capture effectiveness on bacteria annihilation are taking place at the Soreq nuclear reactor.

  5. Folate Functionalized Boron Nitride Nanotubes and their Selective Uptake by Glioblastoma Multiforme Cells: Implications for their Use as Boron Carriers in Clinical Boron Neutron Capture Therapy.

    Science.gov (United States)

    Ciofani, Gianni; Raffa, Vittoria; Menciassi, Arianna; Cuschieri, Alfred

    2008-11-25

    Boron neutron capture therapy (BNCT) is increasingly being used in the treatment of several aggressive cancers, including cerebral glioblastoma multiforme. The main requirement for this therapy is selective targeting of tumor cells by sufficient quantities of (10)B atoms required for their capture/irradiation with low-energy thermal neutrons. The low content of boron targeting species in glioblastoma multiforme accounts for the difficulty in selective targeting of this very malignant cerebral tumor by this radiation modality. In the present study, we have used for the first time boron nitride nanotubes as carriers of boron atoms to overcome this problem and enhance the selective targeting and ablative efficacy of BNCT for these tumors. Following their dispersion in aqueous solution by noncovalent coating with biocompatible poly-l-lysine solutions, boron nitride nanotubes were functionalized with a fluorescent probe (quantum dots) to enable their tracking and with folic acid as selective tumor targeting ligand. Initial in vitro studies have confirmed substantive and selective uptake of these nanovectors by glioblastoma multiforme cells, an observation which confirms their potential clinical application for BNCT therapy for these malignant cerebral tumors.

  6. Folate Functionalized Boron Nitride Nanotubes and their Selective Uptake by Glioblastoma Multiforme Cells: Implications for their Use as Boron Carriers in Clinical Boron Neutron Capture Therapy

    Directory of Open Access Journals (Sweden)

    Ciofani Gianni

    2008-01-01

    Full Text Available Abstract Boron neutron capture therapy (BNCT is increasingly being used in the treatment of several aggressive cancers, including cerebral glioblastoma multiforme. The main requirement for this therapy is selective targeting of tumor cells by sufficient quantities of10B atoms required for their capture/irradiation with low-energy thermal neutrons. The low content of boron targeting species in glioblastoma multiforme accounts for the difficulty in selective targeting of this very malignant cerebral tumor by this radiation modality. In the present study, we have used for the first time boron nitride nanotubes as carriers of boron atoms to overcome this problem and enhance the selective targeting and ablative efficacy of BNCT for these tumors. Following their dispersion in aqueous solution by noncovalent coating with biocompatible poly-l-lysine solutions, boron nitride nanotubes were functionalized with a fluorescent probe (quantum dots to enable their tracking and with folic acid as selective tumor targeting ligand. Initial in vitro studies have confirmed substantive and selective uptake of these nanovectors by glioblastoma multiforme cells, an observation which confirms their potential clinical application for BNCT therapy for these malignant cerebral tumors.

  7. Effect of 10B isotope and vacancy defects on the phonon modes of two-dimensional hexagonal boron nitride

    Science.gov (United States)

    Sherajul Islam, Md.; Anindya, Khalid N.; Bhuiyan, Ashraful G.; Tanaka, Satoru; Makino, Takayuki; Hashimoto, Akihiro

    2018-02-01

    We report the details of the effects of the 10B isotope and those of B and N vacancies combined with the isotope on the phonon modes of two-dimensional hexagonal boron nitride (h-BN). The phonon density of states and localization problems are solved using the forced vibrational method, which is suitable for an intricate and disordered system. We observe an upward shift of Raman-active E2g-mode optical phonons (32 cm‑1) for a 100% 10B isotope, which matches well with the experiment and simple harmonic oscillator model. However, a downward shift of E2g-mode phonons is observed for B or N vacancies and the combination of the isotope and vacancy-type disordered BN. Strong localized eigenmodes are found for all types of defects, and a typical localization length is on the order of ∼7 nm for naturally occurring BN samples. These results are very important for understanding the heat dissipation and electron transport properties of BN-based nanoelectronics.

  8. Manufacturing of thin films of boron for the measurement of the {sup 10}B(n, {alpha}){sup 7} Li reaction used in BNCT

    Energy Technology Data Exchange (ETDEWEB)

    Smilgys, Barbara; Oliveira, Sandro Guedes de; Hadler Neto, Julio Cesar; Vellame, Igor Alencar [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin; Soares, Cleber Jose; Salim, Leonardo Alfredo [Universidade Estadual Paulista (UNESP), Rio Claro, SP (Brazil). Inst. de Geociencias e Ciencias Exatas; Coelho, Paulo Rogerio Pinto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Engenharia Nuclear

    2011-07-01

    Full text: The Boron Neutron Capture Therapy (BNCT) is considered to be a possible treatment for different types of aggressive cancers located in areas of difficult access or which already have metastasis. The working principle of this therapy is the selective delivery of a greater amount of boron to the tumor cells than to the healthy ones, followed by the neutron irradiation that will induce the emission of {alpha} particles through the {sup 10}B(n, {alpha}){sup 7} Li reaction used in BNCT reaction. The high energy deposition of the product particles causes the death of the cells and this therapy becomes much effective if the healthy tissue is less exposed to this radiation. The objective of this work is to develop a method for measuring the rate of this reaction by using thin films of boron. We have manufactured thin films with different concentrations of boron deposited on mica and the thin films were exposed to different irradiation time intervals at the reactor IEA-R1 located at IPEN, Sao Paulo. Here we show our first results on the density and uniformity of the thin films, where the detection of the particles is made using plastic track detectors (CR-39) which have their structures damaged by the passage of ions. (author)

  9. Isotopic Enrichment of Boron in the Sputtering of Boron Nitride with Xenon Ions

    Science.gov (United States)

    Ray, P. K.; Shutthanandan, V.

    1998-01-01

    An experimental study is described to measure the isotopic enrichment of boron. Xenon ions from 100 eV to 1.5 keV were used to sputter a boron nitride target. An ion gun was used to generate the ion beam. The ion current density at the target surface was approximately 30 microA/sq cm. Xenon ions impinged on the target surface at 50 deg angle to the surface normal. Since boron nitride is an insulator, a flood electron gun was used in our experiments to neutralize the positive charge buildup on the target surface. The sputtered secondary ions of boron were detected by a quadrupole mass spectrometer. The spectrometer entrance aperture was located perpendicular to the ion beam direction and 10 mm away from the target surface. The secondary ion flux was observed to be enriched in the heavy isotopes at lower ion energies. The proportion of heavy isotopes in the sputtered secondary ion flux was found to decrease with increasing primary ion energy from 100 to 350 eV. Beyond 350 eV, light isotopes were sputtered preferentially. The light isotope enrichment factor was observed to reach an asymptotic value of 1.27 at 1.5 keV. This trend is similar to that of the isotopic enrichment observed earlier when copper was sputtered with xenon ions in the same energy range.

  10. Effects of boron addition on a-Si90Ge10:H films obtained by low frequency plasma enhanced chemical vapour deposition

    International Nuclear Information System (INIS)

    Perez, Arllene M; Renero, Francisco J; Zuniga, Carlos; Torres, Alfonso; Santiago, Cesar

    2005-01-01

    Optical, structural and electric properties of (a-(Si 90 Ge 10 ) 1-y B y :H) thin film alloys, deposited by low frequency plasma enhanced chemical vapour deposition, are presented. The chemical bonding structure has been studied by IR spectroscopy, while the composition was investigated by Raman spectroscopy. A discussion about boron doping effects, in the composition and bonding of samples, is presented. Transport of carriers has been studied by measurement of the conductivity dependence on temperature, which increases from 10 -3 to 10 1 Ω -1 cm -1 when the boron content varies from 0 to 50%. Similarly, the activation energy is between 0.62 and 0.19 eV when the doping increases from 0 to 83%. The optical properties have been determined from the film's optical transmission, using Swanepoel's method. It is shown that the optical gap varies from 1.3 to 0.99 eV

  11. The enhancement of thermal-neutron induced cell death by 10-boron dextran

    International Nuclear Information System (INIS)

    Ujeno, Y.; Akaboshi, M.; Maki, H.; Kawai, K.; Kanda, K.; Kobayashi, T.; Ono, K.; Kitaoka, Y.; Abraham, R.; Gabel, D.

    1989-01-01

    The new membranophilic compound, 10-B dextran, is active not only in reducing the surviving fraction of mammalian cells through the mechanism of high RBE values, but also in enhancing the radiosensitivity of the cells. (orig./MG)

  12. Pilot clinical study of boron neutron capture therapy for recurrent hepatic cancer involving the intra-arterial injection of a 10BSH-containing WOW emulsion

    International Nuclear Information System (INIS)

    Yanagie, Hironobu; Higashi, Syushi; Seguchi, Koji; Ikushima, Ichiro; Fujihara, Mituteru; Nonaka, Yasumasa; Oyama, Kazuyuki; Maruyama, Syoji; Hatae, Ryo; Suzuki, Minoru; Masunaga, Shin-ichiro; Kinashi, Tomoko; Sakurai, Yoshinori; Tanaka, Hiroki; Kondo, Natsuko; Narabayashi, Masaru; Kajiyama, Tetsuya; Maruhashi, Akira; Ono, Koji; Nakajima, Jun

    2014-01-01

    A 63-year-old man with multiple HCC in his left liver lobe was enrolled as the first patient in a pilot study of boron neutron capture therapy (BNCT) involving the selective intra-arterial infusion of a 10 BSH-containing water-in-oil-in-water emulsion ( 10 BSH-WOW). The size of the tumorous region remained stable during the 3 months after the BNCT. No adverse effects of the BNCT were observed. The present results show that 10 BSH-WOW can be used as novel intra-arterial boron carriers during BNCT for HCC. - Highlights: • We started the pilot clinical study of BNCT to recurrence hepatic cancer. • The tumor size was remained stable during 3 months after BNCT(SD). • No adverse effect as a result of BNCT was observed during follow-up period. • 10 B-containing WOW emulsion can be applied as a novel intra-arterial boron carrier for BNCT for HCC

  13. Boron-11 MRI and MRS of intact animals infused with a boron neutron capture agent

    International Nuclear Information System (INIS)

    Kabalka, G.W.; Davis, M.; Bendel, P.

    1988-01-01

    Boron neutron capture therapy (BNCT) depends on the delivery of boron-containing drugs to a targeted lesion. Currently, the verification and quantification of in vivo boron content is a difficult problem. Boron-11 spectroscopy was utilized to confirm the presence of a dimeric sulfhydryl dodecaborane BNCT agent contained in an intact animal. Spectroscopy experiments revealed that the decay time of transverse magnetization of the boron-11 spins was less than 1 ms which precluded the use of a 2DFT imaging protocol. A back-projection protocol was developed and utilized to generate the first boron-11 image of a BNCT agent in the liver of an intact Fisher 344 rat

  14. A 10-fold improvement in the precision of boron isotopic analysis by negative thermal ionization mass spectrometry.

    Science.gov (United States)

    Shen, Jason Jiun-San; You, Chen-Feng

    2003-05-01

    Boron isotopes are potentially very important to cosmochemistry, geochemistry, and paleoceanography. However, the application has been hampered by the large sample required for positive thermal ionization mass spectrometry (PTIMS), and high mass fractionation for negative-TIMS (NTIMS). Running as BO(2)(-), NTIMS is very sensitive and requires only nanogram sized samples, but it has rather poor precision (approximately 0.7-2.0 per thousand) as a result of the larger mass fractionation associated with the relatively light ion. In contrast, running as the much heavier molecule of Cs(2)BO(2)(+), PTIMS usually achieves better precision around 0.1-0.4 per thousand. Moreover, there is a consistent 10 per thousand offset in the (11)B/(10)B ratio for NIST SRM 951 standard boric acid between the NTIMS and the certified value, but the cause of this offset is unclear. In this paper, we have adapted a technique we developed earlier to measure the (138)La/(139)La using LaO(+) (1) to improve the NTIMS technique for BO(2). We were able to correct for instrumental fractionation by measuring BO(2)(-) species not only at masses of 42 and 43, but also at 45, which enabled us to normalize (45)BO(2)/(43)BO(2) to an empirical (18)O/(16)O value. We found that both I(45)/I(42) = ((11)B(16)O(18)O/(10)B(16)O(16)O) and (I(43)/I(42))(C) = ((11)B(16)O(16)O/(10)B(16)O(16)O) vary linearly with (I(45)/I(43))(C) x 0.5 = ((11)B(16)O(18)O/(11)B(16)O(16)O) x 0.5 = (18)O/(16)O. In addition, different activators and different chemical forms of B yield different slopes for the fractionation lines. After normalizing (11)B(16)O(18)O/(11)B(16)O(16)O x 0.5 to a fixed (18)O/(16)O value, we obtained a mean (11)B/(10)B value of NIST SRM 951 that matches the NIST certified value at 4.0430 +/- 0.0015 (+/-0.36 per thousand, n = 11). As a result, our technique can achieve precision and accuracy comparable to that of PTIMS with only 1 per thousand of the sample required. This new NTIMS technique for B isotopes is

  15. Study of ceramic mixed boron element as a neutron shielding

    International Nuclear Information System (INIS)

    Ismail Mustapha; Mohd Reusmaazran Yusof; Md Fakarudin Ab Rahman; Nor Paiza Mohamad Hasan; Samihah Mustaffha; Yusof Abdullah; Mohamad Rabaie Shari; Airwan Affandi Mahmood; Nurliyana Abdullah; Hearie Hassan

    2012-01-01

    Shielding upon radiation should not be underestimated as it can causes hazard to health. Precautions on the released of radioactive materials should be well concerned and considered. Therefore, the combination of ceramic and boron make them very useful for shielding purpose in areas of low and intermediate neutron. A six grades of ceramic tile have been produced namely IMN05 - 5 % boron, IMN06 - 6 % boron, IMN07 - 7 % boron, IMN08 - 8 % boron, IMN09 - 9 % boron, IMN10 - 10 % boron from mixing, press and sintered process. Boron is a material that capable of absorbing and capturing neutron, so that neutron and gamma test were conducted to analyze the effectiveness of boron material in combination with ceramic as shielding. From the finding, percent reduction number of count per minute shows the ceramic tiles are capable to capture neutron. Apart from all the percentage of boron used, 10 % is the most effective shields since the percent reduction indicating greater neutron captured increased. (author)

  16. Micrometric rods grown by nanosecond pulsed laser deposition of boron carbide

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Quintas, Ignacio; Oujja, Mohamed; Sanz, Mikel; Benitez-Cañete, Antonio [Instituto de Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain); Chater, Richard J. [Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Cañamares, Maria Vega [Instituto de Estructura de la Materia, CSIC, Serrano 119, 28006 Madrid (Spain); Marco, José F. [Instituto de Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain); Castillejo, Marta, E-mail: marta.castllejo@iqfr.csic.es [Instituto de Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain)

    2015-02-15

    Highlights: • Micrometric rods obtained by ns pulsed laser deposition of boron carbide at 1064 and 266 nm. • At 1064 nm microrods display crystalline polyhedral shape with sharp edges and flat sides. • Microrods consist of a mixture of boron, boron oxide, boron carbide and aliphatic hydrocarbons. - Abstract: Micrometric size rods have been fabricated via pulsed laser deposition in vacuum from boron carbide targets using nanosecond pulses of 1064 and 266 nm and room temperature Si (1 0 0) substrates. Morphological, structural and chemical characterization of the microrods was made by applying scanning electron microscopy, focussed ion beam microscopy coupled to secondary ion mass spectrometry, X-ray diffraction, X-ray photoelectron spectroscopy and micro-Raman spectroscopy. Ablation at 1064 nm favours the formation of microrods with high aspect ratio, sharp edges and pyramidal tips, typically 10 μm long with a cross section of around 2 μm × 2 μm. Differently, at 266 nm the microrods are of smaller size and present a more globular aspect. The analyses of the microrods provide information about their crystalline nature and composition, based on a mixture which includes boron, boron oxide and boron carbide, and allows discussion of the wavelength dependent growth mechanisms involved.

  17. Synthesis of o-carboranylmethyl ethers of steroids as potential target substrates for boron neutron capture therapy

    International Nuclear Information System (INIS)

    Schneiderova, L.; Gruener, B.; Strouf, O.; Kimlova, I.

    1992-01-01

    o-carboranylmethyl ethers of steroids were synthesized by insertion of steroidal 2-propynyloxy derivatives into 6,9-bis(acetonitrile)decarborane. This reaction provided compounds with an estrane and androstane skeleton, potentially useful in boron neutron capture therapy of hormone-sensitive forms of cancer: 17β-o-carboranylmethyl ether of estradiol IXb (yield 14%) and 3β- and 17β-carboranylmethyl ethers of androstenediol Vb and VIIb (yield 12% and 13%, respectively). Jones oxidation gave the carboranyl derivative of androsten-17-one VIb in 75% yield. As shown by a study of insertion of 3β-(2-propynyloxy)cholest-5-ene (IVa), the low yields of the insertion reaction cannot be increased by change in the reaction conditions. The relative binding affinity of compound IXb to the estrogen receptor from rat uterine and human breast tumor cytosol was 3.0 and 0.29%, respectively, of that of estradiol. (author) 2 figs., 2 tabs., 20 refs

  18. Photo-induced site-specific nitridation of plasma-deposited B 10C 2H x films: A new pathway toward post-deposition doping of semiconducting boron carbides

    Science.gov (United States)

    Behera, Swayambhu; Wilks, Justin; Dowben, Peter A.; Driver, M. Sky; Caruso, A. N.; Kelber, Jeffry A.

    2010-10-01

    We show that dopant impurities can be introduced in a controlled, site-specific manner into pre-deposited semiconducting boron carbide films. B―N bond formation has been characterized by X-ray photoelectron spectroscopy for semiconducting B 10C 2H x films exposed to vacuum ultraviolet photons in the presence of NH 3. Core level photoemission data indicate that B―NH 2 bonds are formed at B sites bonded to other boron atoms (B―B), and not at boron atoms adjacent to carbon atoms (B―C) or at carbon atom sites. Nitridation obeys diffusion-limited kinetics. These results indicate that dopant species can be introduced in a controlled, site-specific manner into pre-deposited boron carbide films, as opposed to currently required dopant incorporation during the deposition process.

  19. Application of 10BSH entrapped transferrin-PEG-liposome to boron neutron-capture therapy (BNCT) for solid tumor

    International Nuclear Information System (INIS)

    Maruyama, K.; Ishida, O.; Iwatsuru, M.; Yanagie, H.; Eriguchi, M.; Kobayashi, H.

    2000-01-01

    The successful treatment of cancer by BNCT requires the selective concentration of 10 B within malignant tumor cells. Intracellular targeting ability and cytotoxic effects of 10 B entrapped TF-PEG-liposomes, in which TF is covalently linked to the distal terminal of PEG chains on the external surface of PEG-liposomes, were examined in Colon 26 tumor-bearing mice. TF-PEG-liposomes readily bound to tumor cells in vivo, and were internalized by receptor-mediated endocytosis. 10 B-PEG-liposomes and 10 B-TF-PEG-liposomes showed prolonged residence time in the circulation and low RES uptake in tumor-bearing mice, resulting in enhanced extravasation of the liposomes into the solid tumor tissue and reached high level of 10 B content in tumor. After thermal neutron irradiation of mice injected with 10 B-PEG-liposomes or 10 B-TF-PEG-liposome, tumor growth was suppressed relative to controls. These results suggest that intravenous injection of 10 B TF-PEG-liposome can increase the intracellular retention of 10 B atoms, which were introduced by receptor mediated endocytosis after binding, causing tumor growth suppression in vivo upon thermal neutron irradiation. (author)

  20. Experimental Studies of Boronophenylalanine ({sup 10}BPA) Biodistribution for the Individual Application of Boron Neutron Capture Therapy (BNCT) for Malignant Melanoma Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Carpano, Marina; Perona, Marina; Rodriguez, Carla [Department of Radiobiology, National Atomic Energy Commission, San Martín (Argentina); Nievas, Susana; Olivera, Maria; Santa Cruz, Gustavo A. [Department of Boron Neutron Capture Therapy, National Atomic Energy Commission, San Martín (Argentina); Brandizzi, Daniel; Cabrini, Romulo [Department of Radiobiology, National Atomic Energy Commission, San Martín (Argentina); School of Dentistry, University of Buenos Aires, Buenos Aires (Argentina); Pisarev, Mario [Department of Radiobiology, National Atomic Energy Commission, San Martín (Argentina); National Research Council of Argentina, Buenos Aires (Argentina); Department of Human Biochemistry, School of Medicine, University of Buenos Aires, Buenos Aires (Argentina); Juvenal, Guillermo Juan [Department of Radiobiology, National Atomic Energy Commission, San Martín (Argentina); National Research Council of Argentina, Buenos Aires (Argentina); Dagrosa, Maria Alejandra, E-mail: dagrosa@cnea.gov.ar [Department of Radiobiology, National Atomic Energy Commission, San Martín (Argentina); National Research Council of Argentina, Buenos Aires (Argentina)

    2015-10-01

    Purpose: Patients with the same histopathologic diagnosis of cutaneous melanoma treated with identical protocols of boron neutron capture therapy (BNCT) have shown different clinical outcomes. The objective of the present studies was to evaluate the biodistribution of boronophenilalanina ({sup 10}BPA) for the potential application of BNCT for the treatment of melanoma on an individual basis. Methods and Materials: The boronophenilalanine (BPA) uptake was evaluated in 3 human melanoma cell lines: MEL-J, A375, and M8. NIH nude mice were implanted with 4 10{sup 6} MEL-J cells, and biodistribution studies of BPA (350 mg/kg intraperitoneally) were performed. Static infrared imaging using a specially modified infrared camera adapted to measure the body infrared radiance of small animals was used. Proliferation marker, Ki-67, and endothelial marker, CD31, were analyzed in tumor samples. Results: The in vitro studies demonstrated different patterns of BPA uptake for each analyzed cell line (P<.001 for MEL-J and A375 vs M8 cells). The in vivo studies showed a maximum average boron concentration of 25.9 ± 2.6 μg/g in tumor, with individual values ranging between 11.7 and 52.0 μg/g of {sup 10}B 2 hours after the injection of BPA. Tumor temperature always decreased as the tumors increased in size, with values ranging between 37°C and 23°C. A significant correlation between tumor temperature and tumor-to-blood boron concentration ratio was found (R{sup 2} = 0.7, rational function fit). The immunohistochemical studies revealed, in tumors with extensive areas of viability, a high number of positive cells for Ki-67, blood vessels of large diameter evidenced by the marker CD31, and a direct logistic correlation between proliferative status and boron concentration difference between tumor and blood (R{sup 2} = 0.81, logistic function fit). Conclusion: We propose that these methods could be suitable for designing new screening protocols applied before melanoma BNCT

  1. Studies on Separation Process and Production Technology of Boron Isotope

    OpenAIRE

    LI Jian-ping

    2014-01-01

    The boron isotopes separation test was performed by chemical exchange reaction in the benzene ether -three boron fluoride system, which resulted to the boron isotopic enrichment of -10 in the liquid phase, the boron isotopic enrichment of -11 in the gas phase. After then, boron isotope separation trial production has been finished. In this process, the exchange column and complex tower normal operating parameters and the complex tower technology have been obtained, the problems of material di...

  2. Crystalline boron nitride aerogels

    Energy Technology Data Exchange (ETDEWEB)

    Zettl, Alexander K.; Rousseas, Michael; Goldstein, Anna P.; Mickelson, William; Worsley, Marcus A.; Woo, Leta

    2017-12-12

    This disclosure provides methods and materials related to boron nitride aerogels. For example, one aspect relates to a method for making an aerogel comprising boron nitride, comprising: (a) providing boron oxide and an aerogel comprising carbon; (b) heating the boron oxide to melt the boron oxide and heating the aerogel; (c) mixing a nitrogen-containing gas with boron oxide vapor from molten boron oxide; and (d) converting at least a portion of the carbon to boron nitride to obtain the aerogel comprising boron nitride. Another aspect relates to a method for making an aerogel comprising boron nitride, comprising heating boron oxide and an aerogel comprising carbon under flow of a nitrogen-containing gas, wherein boron oxide vapor and the nitrogen-containing gas convert at least a portion of the carbon to boron nitride to obtain the aerogel comprising boron nitride.

  3. Boron analyses in the reactor coolant system of French PWR by acid-base titration ([B]) and ICP-MS (10B atomic %): key to NPP safety

    International Nuclear Information System (INIS)

    Jouvet, Fabien; Roux, Sylvie; Carabasse, Stephanie; Felgines, Didier

    2012-09-01

    Boron is widely used by Nuclear Power Plants and especially by EDF Pressurized Water Reactors to ensure the control of the neutron rate in the reactor coolant system and, by this way, the fission reaction. The Boron analysis is thus a major factor of safety which enables operators to guarantee the permanent control of the reactor. Two kinds of analyses carried out by EDF on the Boron species, recently upgraded regarding new method validation standards and developed to enhance the measurement quality by reducing uncertainties, will be discussed in this topic: Acid-Base titration of Boron and Boron isotopic composition by Inductively Coupled Plasma Mass Spectrometer - ICP MS. (authors)

  4. Biodistribution of Boron compounds in an experimental model of liver metastases for Boron Neutron Capture (BNCT) Studies

    International Nuclear Information System (INIS)

    Garabalino, Marcela A.; Monti Hughes, Andrea; Molinari, Ana J.; Heber, Elisa M.; Pozzi, Emiliano C.C.; Itoiz, Maria E.; Trivillin, Veronica A.; Schwint, Amanda E.; Nievas, Susana; Aromando, Romina F.

    2009-01-01

    Boron Neutron Capture Therapy (BNCT) is a binary treatment modality that involves the selective accumulation of 10 B carriers in tumors followed by irradiation with thermal or epithermal neutrons. The high linear energy transfer alpha particles and recoiling 7 Li nuclei emitted during the capture of a thermal neutron by a 10 B nucleus have a short range and a high biological effectiveness. Thus, BNCT would potentially target neoplastic tissue selectively. In previous studies we demonstrated the therapeutic efficacy of different BNCT protocols in an experimental model of oral cancer. More recently we performed experimental studies in normal rat liver that evidenced the feasibility of treating liver metastases employing a novel BNCT protocol proposed by JEC based on ex-situ treatment and partial liver auto-transplant. The aim of the present study was to perform biodistribution studies with different boron compounds and different administration protocols to determine the protocols that would be therapeutically useful in 'in vivo' BNCT studies at the RA-3 Nuclear Reactor in an experimental model of liver metastases in rats. Materials and Methods. A total of 70 BDIX rats (Charles River Lab., MA, USA) were inoculated in the liver with syngeneic colon cancer cells DH/DK12/TRb (ECACC, UK) to induce the development of subcapsular metastatic nodules. 15 days post-inoculation the animals were used for biodistribution studies. A total of 11 protocols were evaluated employing the boron compounds boronophenylalanine (BPA) and GB-10 (Na 2 10 B 1 -0H 10 ), alone or combined employing different doses and administration routes. Tumor, normal tissue and blood samples were processed for boron measurement by ICP-OES. Results. Several protocols proved potentially useful for BNCT studies in terms of absolute boron concentration in tumor and preferential uptake of boron by tumor tissue, i.e. BPA 15.5 mg 10 B/kg iv + GB-10 50 mg 10 B/kg iv; BPA 46.5 mg 10 B/kg ip; BPA 46.5 mg 10 B/kg ip

  5. Study of the boron levels in serum after implantation of different ratios nano-hexagonal boron nitride–hydroxy apatite in rat femurs

    Energy Technology Data Exchange (ETDEWEB)

    Atila, Alptug, E-mail: alptugatila@yahoo.com [Department of Analytical Chemistry, Faculty of Pharmacy, Ataturk University, Erzurum 25240 (Turkey); Halici, Zekai; Cadirci, Elif [Department of Pharmacology, Faculty of Medicine, Ataturk University, Erzurum 25240 (Turkey); Karakus, Emre [Department of Pharmacology and Toxicology, School of Veterinary Medicine, Ataturk University, Erzurum 25240 (Turkey); Palabiyik, Saziye Sezin [Department of Pharmaceutical Toxicology, Faculty of Pharmacy, Ataturk University, Erzurum 25240 (Turkey); Ay, Nuran [Department of Material Science and Engineering, Faculty of Engineering, Anadolu University, Eskisehir 26555 (Turkey); Bakan, Feray [Sabancı University Nanotechnology Research and Application Center (SUNUM), Istanbul 34956 (Turkey); Yilmaz, Sahin [Department of Genetics and Bioengineering, Faculty of Engineering and Architecture, Yeditepe University, Istanbul 34755 (Turkey)

    2016-01-01

    ABSTRACT: Boron and its derivatives are effective in bone recovery and osteointegration. However, increasing the boron levels in body liquids may cause toxicity. The aim of our study is to investigate serum boron levels using ICP-MS after implantation of different ratios of nano-hBN–HA composites in rat femurs. All rats were (n = 126) divided into five experimental groups (n = 24) and one healthy group (6 rats); healthy (Group1), femoral defect + %100HA (Group2), femoral defect + %2.5hBN + %97.5HA (Group3), femoral defect + %5hBN + %95HA (Group4), femoral defect + %10hBN + %90 HA (Group5), femoral defect + %100hBN (Group6). The femoral defect was created in the distal femur (3 mm drill-bit). Each implant group was divided into four different groups (n = 24) also 6 rats sacrificed for each groups in one week intervals during four weeks. In our results; at 1, 2, 3, and 4 weeks after implantation near bone tissue, serum levels of boron were evaluated using ICP-MS. We demonstrated that neither short-term nor long-term implantation of hBN–HA composite resulted in statistically increased serum boron levels in experimental groups compared to healthy group. In conclusion, this study investigated the implant material produced form hBN–HA for the first time. Our data suggest that hBN is a new promising target for biomaterial and implant bioengineers. - Highlights: • Nano-hBN–HA composites are new targets for biomaterial and implant bioengineers. • Serum boron levels were researched after implantation of nano-hBN–HA composites. • Implantation of hBN–HA composite did not result in increased serum boron levels. • The use of boron in composite form with HA did not change the stability of the implant.

  6. MRO CRISM TARGETED EMPIRICAL RECORD V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This volume contains the CRISM Targeted Empirical Record (TER) archive, a collection of multiband image cubes derived from targeted (gimbaled) observations of Mars'...

  7. Micrometric rods grown by nanosecond pulsed laser deposition of boron carbide

    Science.gov (United States)

    Lopez-Quintas, Ignacio; Oujja, Mohamed; Sanz, Mikel; Benitez-Cañete, Antonio; Chater, Richard J.; Cañamares, Maria Vega; Marco, José F.; Castillejo, Marta

    2015-02-01

    Micrometric size rods have been fabricated via pulsed laser deposition in vacuum from boron carbide targets using nanosecond pulses of 1064 and 266 nm and room temperature Si (1 0 0) substrates. Morphological, structural and chemical characterization of the microrods was made by applying scanning electron microscopy, focussed ion beam microscopy coupled to secondary ion mass spectrometry, X-ray diffraction, X-ray photoelectron spectroscopy and micro-Raman spectroscopy. Ablation at 1064 nm favours the formation of microrods with high aspect ratio, sharp edges and pyramidal tips, typically 10 μm long with a cross section of around 2 μm × 2 μm. Differently, at 266 nm the microrods are of smaller size and present a more globular aspect. The analyses of the microrods provide information about their crystalline nature and composition, based on a mixture which includes boron, boron oxide and boron carbide, and allows discussion of the wavelength dependent growth mechanisms involved.

  8. Efficient Boron Nitride Nanotube Formation via Combined Laser-Gas Flow Levitation

    Science.gov (United States)

    Whitney, R. Roy (Inventor); Jordan, Kevin (Inventor); Smith, Michael W. (Inventor)

    2014-01-01

    A process for producing boron nitride nanotubes and/or boron-carbon-nitrogen nanotubes of the general formula B(sub x)C(sub y)N(sub z) The process utilizes a combination of laser light and nitrogen gas flow to support a boron ball target during heating of the boron ball target and production of a boron vapor plume which reacts with nitrogen or nitrogen and carbon to produce boron nitride nanotubes and/or boron-carbon-nitrogen nanotubes of the general formula B(sub x)C(sub y)N(sub z).

  9. Efficient Boron-Carbon-Nitrogen Nanotube Formation Via Combined Laser-Gas Flow Levitation

    Science.gov (United States)

    Whitney, R. Roy (Inventor); Jordan, Kevin (Inventor); Smith, Michael W. (Inventor)

    2015-01-01

    A process for producing boron nitride nanotubes and/or boron-carbon-nitrogen nanotubes of the general formula BxCyNz. The process utilizes a combination of laser light and nitrogen gas flow to support a boron ball target during heating of the boron ball target and production of a boron vapor plume which reacts with nitrogen or nitrogen and carbon to produce boron nitride nanotubes and/or boron-carbon-nitrogen nanotubes of the general formula BxCyNz.

  10. Boron atom reactions

    International Nuclear Information System (INIS)

    Estes, R.; Tabacco, M.B.; Digiuseppe, T.G.; Davidovits, P.

    1982-01-01

    The reaction rates of atomic boron with various epoxides have been measured in a flow tube apparatus. The bimolecular rate constants, in units of cm 3 molecule -1 s -1 , are: 1,2-epoxypropane (8.6 x 10 -11 ), 1,2-epoxybutane (8.8 x 10 -11 ), 1,2,3,4-diepoxybutane (5.5 x 10 -11 ), 1-chloro-2,3-epoxypropane (5.7 x 10 -11 ), and 1,2-epoxy-3,3,3-trichloropropane (1.5 x 10 -11 ). (orig.)

  11. An Assessment of the Potential Use of BNNTs for Boron Neutron Capture Therapy.

    Science.gov (United States)

    Ferreira, Tiago H; Miranda, Marcelo C; Rocha, Zildete; Leal, Alexandre S; Gomes, Dawidson A; Sousa, Edesia M B

    2017-04-12

    Currently, nanostructured compounds have been standing out for their optical, mechanical, and chemical features and for the possibilities of manipulation and regulation of complex biological processes. One of these compounds is boron nitride nanotubes (BNNTs), which are a nanostructured material analog to carbon nanotubes, but formed of nitrogen and boron atoms. BNNTs present high thermal stability along with high chemical inertia. Among biological applications, its biocompatibility, cellular uptake, and functionalization potential can be highlighted, in addition to its eased utilization due to its nanometric size and tumor cell internalization. When it comes to new forms of therapy, we can draw attention to boron neutron capture therapy (BNCT), an experimental radiotherapy characterized by a boron-10 isotope carrier inside the target and a thermal neutron beam focused on it. The activation of the boron-10 atom by a neutron generates a lithium atom, a gamma ray, and an alpha particle, which can be used to destroy tumor tissues. The aim of this work was to use BNNTs as a boron-10 carrier for BNCT and to demonstrate its potential. The nanomaterial was characterized through XRD, FTIR, and SEM. The WST-8 assay was performed to confirm the cell viability of BNNTs. The cells treated with BNNTs were irradiated with the neutron beam of a Triga reactor, and the apoptosis caused by the activation of the BNNTs was measured with a calcein AM/propidium iodide test. The results demonstrate that this nanomaterial is a promising candidate for cancer therapy through BNCT.

  12. Boron neutron capture synovectomy (BNCS) as a potential therapy for rheumatoid arthritis: boron biodistribution study in a model of antigen-induced arthritis in rabbits.

    Science.gov (United States)

    Trivillin, Verónica A; Abramson, David B; Bumaguin, Gaston E; Bruno, Leandro J; Garabalino, Marcela A; Monti Hughes, Andrea; Heber, Elisa M; Feldman, Sara; Schwint, Amanda E

    2014-11-01

    Boron neutron capture synovectomy (BNCS) is explored for the treatment of rheumatoid arthritis (RA). The aim of the present study was to perform boron biodistribution studies in a model of antigen-induced arthritis (AIA) in female New Zealand rabbits, with the boron carriers boronophenylalanine (BPA) and sodium decahydrodecaborate (GB-10) to assess the potential feasibility of BNCS for RA. Rabbits in chronic phase of AIA were used for biodistribution studies employing the following protocols: intra-articular (ia) (a) BPA-f 0.14 M (0.7 mg (10)B), (b) GB-10 (5 mg (10)B), (c) GB-10 (50 mg (10)B) and intravenous (iv), (d) BPA-f 0.14 M (15.5 mg (10)B/kg), (e) GB-10 (50 mg (10)B/kg), and (f) BPA-f (15.5 mg (10)B/kg) + GB-10 (50 mg (10)B/kg). At different post-administration times (13-85 min for ia and 3 h for iv), samples of blood, pathological synovium (target tissue), cartilage, tendon, muscle, and skin were taken for boron measurement by inductively coupled plasma mass spectrometry. The intra-articular administration protocols at boron concentrations (>20 ppm) in the pathological synovium. Dosimetric estimations suggest that BNCS would be able to achieve a therapeutically useful dose in pathological synovium without exceeding the radiotolerance of normal tissues in the treatment volume, employing boron carriers approved for use in humans. Radiobiological in vivo studies will be necessary to determine the actual therapeutic efficacy of BNCS to treat RA in an experimental model.

  13. Considerations for boron neutron capture therapy studies

    International Nuclear Information System (INIS)

    Faria Gaspar, P. de.

    1994-01-01

    Radiotherapy is indispensable as a mean to eradicate deeply or infiltrating tumor tissue that can not be removed surgically. Therefore, it is not selective and may also kill the surrounding health tissue. The principle of BNCT (Boron Neutron Capture Therapy) consist in targeting a tumor selectively with a boron-10 compound. This nuclide has a large capture cross section for thermal neutrons and the nuclear reaction and the delivered energy in locus will selective the tumor. Since its initial proposal in 1963 BNCT has made much progress, however it is not used in a routine treatment. In this work it was approached some complex procedures, as the obtention of selective boron compounds, the adequate set up of neutron beams, the biodistribution, the in vivo and in vitro studies, and also human patients treatments. This work provide fundamentals about BNCT to professional of different areas of knowledge since it comprises multidisciplinary study. It includes appendixes for the ones not related to the field for a better comprehension of the many aspects involved. It is also presented a glossary containing technical and basic aspects involved. It is also presented a glossary containing technical and basic terms referred in the work. (author). 174 refs, 1 fig, 12 apps

  14. Boron-containing thioureas for neutron capture therapy

    International Nuclear Information System (INIS)

    Ketz, H.

    1993-01-01

    Melanin is produced in large amounts in malignant melanotic melanomas. Because thiourea compounds are covalently incorporated into melanin during its biosynthesis, the preparation of boronated thiourea-derivatives is of particular interest for the BNCT (Boron Neutron Capture Therapy). Accumulation of boron in tumors by means of boronated thiourea-derivatives may therefore provide levels of 10 B which are useful for BNCT. In BNCT the tumor containing the boron compound is irradiated with epithermal neutrons to generate He- and Li-nuclei from the 10 B which can then destroy the tumor cells. Because of the short ranges of these particles (approximately one cell diameter) the damage will be almost exclusively confined to the tumor leaving normal tissue unharmed. High accumulation of 2-mercapto-1-methylimidazole (methimazole) in melanotic melanomas has been described in the literature. Boronated derivatives of methimazole were therefore synthesized. Boron was in the form of a boronic acid, a nido-carbonate and a mercaptoundeca hydro-closo-dodecaborate (BSH). The synthesis of the boron cluster derivatives of methimazole (nido-carborate- and BSH-derivatives) with 9 resp. 12 boron atoms in the molecule were expected to achieve higher concentrations of boron in the tumor than in the case of the boronic acid compound with its single boron atom. (orig.) [de

  15. The effect of boron deficiency on gene expression and boron compartmentalization in sugarbeet

    Science.gov (United States)

    NIP5, BOR1, NIP6, and WRKY6 genes were investigated for their role in boron deficiency in sugar beet, each with a proposed role in boron use in model plant species. All genes showed evidence of polymorphism in fragment size and gene expression in the target genomic DNA and cDNA libraries, with no co...

  16. Boron nitride composites

    Science.gov (United States)

    Kuntz, Joshua D.; Ellsworth, German F.; Swenson, Fritz J.; Allen, Patrick G.

    2017-02-21

    According to one embodiment, a composite product includes: a matrix material including hexagonal boron nitride and one or more borate binders; and a plurality of cubic boron nitride particles dispersed in the matrix material. According to another embodiment, a composite product includes: a matrix material including hexagonal boron nitride and amorphous boron nitride; and a plurality of cubic boron nitride particles dispersed in the matrix material.

  17. Boron Nitride Nanotubes

    Science.gov (United States)

    Smith, Michael W. (Inventor); Jordan, Kevin (Inventor); Park, Cheol (Inventor)

    2012-01-01

    Boron nitride nanotubes are prepared by a process which includes: (a) creating a source of boron vapor; (b) mixing the boron vapor with nitrogen gas so that a mixture of boron vapor and nitrogen gas is present at a nucleation site, which is a surface, the nitrogen gas being provided at a pressure elevated above atmospheric, e.g., from greater than about 2 atmospheres up to about 250 atmospheres; and (c) harvesting boron nitride nanotubes, which are formed at the nucleation site.

  18. In-beam test of the Boron-10 Multi-Grid neutron detector at the IN6 time-of-flight spectrometer at the ILL

    Science.gov (United States)

    Birch, J.; Buffet, J.-C.; Clergeau, J.-F.; Correa, J.; van Esch, P.; Ferraton, M.; Guerard, B.; Halbwachs, J.; Hall-Wilton, R.; Hultman, L.; Höglund, C.; Khaplanov, A.; Koza, M.; Piscitelli, F.; Zbiri, M.

    2014-07-01

    A neutron detector concept based on solid layers of boron carbide enriched in 10B has been in development for the last few years as an alternative for 3He by collaboration between the ILL, ESS and Linköping University. This Multi-Grid detector uses layers of aluminum substrates coated with 10B4C on both sides that are traversed by the incoming neutrons. Detection is achieved using a gas counter readout principle. By segmenting the substrate and using multiple anode wires, the detector is made inherently position sensitive. This development is aimed primarily at neutron scattering instruments with large detector areas, such as time-of-flight chopper spectrometers. The most recent prototype has been built to be interchangeable with the 3He detectors of IN6 at ILL. The 10B detector has an active area of 32 x 48cm2. It was installed at the IN6 instrument and operated for several weeks, collecting data in parallel with the regularly scheduled experiments, thus providing the first side-by-side comparison with the conventional 3He detectors. Results include an efficiency comparison, assessment of the in-detector scattering contribution, sensitivity to gamma-rays and the signal-to-noise ratio in time-of-flight spectra. The good expected performance has been confirmed with the exception of an unexpected background count rate. This has been identified as natural alpha activity in aluminum. New convertor substrates are under study to eliminate this source of background.

  19. TARGET - TASK ANALYSIS REPORT GENERATION TOOL, VERSION 1.0

    Science.gov (United States)

    Ortiz, C. J.

    1994-01-01

    The Task Analysis Report Generation Tool, TARGET, is a graphical interface tool used to capture procedural knowledge and translate that knowledge into a hierarchical report. TARGET is based on VISTA, a knowledge acquisition tool developed by the Naval Systems Training Center. TARGET assists a programmer and/or task expert organize and understand the steps involved in accomplishing a task. The user can label individual steps in the task through a dialogue-box and get immediate graphical feedback for analysis. TARGET users can decompose tasks into basic action kernels or minimal steps to provide a clear picture of all basic actions needed to accomplish a job. This method allows the user to go back and critically examine the overall flow and makeup of the process. The user can switch between graphics (box flow diagrams) and text (task hierarchy) versions to more easily study the process being documented. As the practice of decomposition continues, tasks and their subtasks can be continually modified to more accurately reflect the user's procedures and rationale. This program is designed to help a programmer document an expert's task thus allowing the programmer to build an expert system which can help others perform the task. Flexibility is a key element of the system design and of the knowledge acquisition session. If the expert is not able to find time to work on the knowledge acquisition process with the program developer, the developer and subject matter expert may work in iterative sessions. TARGET is easy to use and is tailored to accommodate users ranging from the novice to the experienced expert systems builder. TARGET is written in C-language for IBM PC series and compatible computers running MS-DOS and Microsoft Windows version 3.0 or 3.1. No source code is supplied. The executable also requires 2Mb of RAM, a Microsoft compatible mouse, a VGA display and an 80286, 386 or 486 processor machine. The standard distribution medium for TARGET is one 5.25 inch 360K

  20. Boron isotopic enrichment by displacement chromatography

    International Nuclear Information System (INIS)

    Mohapatra, K.K.; Bose, Arun

    2014-01-01

    10 B enriched boron is used in applications requiring high volumetric neutron absorption (absorption cross section- 3837 barn for thermal and 1 barn for 1 MeV fast neutron). It is used in fast breeder reactor (as control rod material), in neutron counter, in Boron Neutron Capture Therapy etc. Owing to very small separation factor, boron isotopic enrichment is a complex process requiring large number of separation stages. Heavy Water Board has ventured in industrial scale production of 10 B enriched boron using Exchange Distillation Process as well as Ion Displacement Chromatography Process. Ion Displacement Chromatography process is used in Boron Enrichment Plant at HWP, Manuguru. It is based on isotopic exchange between borate ions (B(OH) 4 - ) on anion exchange resin and boric acid passing through resin. The isotopic exchange takes place due to difference in zero point energy of 10 B and 11 B

  1. Boron removal from geothermal waters by electrocoagulation.

    Science.gov (United States)

    Yilmaz, A Erdem; Boncukcuoğlu, Recep; Kocakerim, M Muhtar; Yilmaz, M Tolga; Paluluoğlu, Cihan

    2008-05-01

    Most of the geothermal waters in Turkey contain extremely high concentration of boron when they are used for irrigation. The use of geothermal waters for irrigation can results in excess amount deposition of boron in soil. On the other hand, a minimal boron concentration is required for irrigational waters. In this study, electrocoagulation (EC) was selected as a treatment process for the removal of boron from thermal waters obtained from Ilica-Erzurum in Turkey. Current density (CD), pH of solution and temperature of solution were selected as operational parameters. The results showed that boron removal efficiency increased from pH 4.0 to 8.0 and decreased at pH 10.0. Although boron removal efficiency was highest at pH 8.0, energy consumption was very high at this pH value compared to other pH intervals. Boron removal efficiency reached to 95% with increasing current density from 1.5 to 6.0 mA/cm(2), but energy consumption was also increased in this interval. At higher temperatures of solution, such as 313 and 333 K, boron removal efficiency increased. At optimum conditions, boron removal efficiency in geothermal water reached up to 95%.

  2. Application of drug delivery system for boron neutron capture therapy. Basic research toward clinical application

    International Nuclear Information System (INIS)

    Yanagie, Hironobu; Takahashi, Hiroyuki

    2010-01-01

    Tumour cell destruction in boron neutron-capture therapy (BNCT) is due to the nuclear reaction between 10 B and thermal neutrons ( 10 B+ 1 n → 7 Li+ 4 He (α) +2.31 MeV (93.7%)/2.79 MeV (6.3%)). The resulting lithium ions and αparticles are high linear energy transfer (LET) particles which give high biological effect. Their short range in tissue (5-9 μm) restricts radiation damage to those cells in which boron atoms are located at the time of neutron irradiation. BNCT has been applied clinically for the treatment of malignant brain tumors, malignant melanoma, head and neck cancer and hepatoma etc, recently. Sodium borocaptate (Na 2 10 B 12 H 11 SH; BSH) and borono-phenylalanine ( 10 BPA) are currently being used in clinical treatments. To achieve the selective delivery of boron atoms to cancer cells, drug delivery system (DDS) becomes an attractive intelligent technology as targeting and controlled release of drugs. We have firstly reported that 10 B atoms delivered by immunoliposomes are cytotoxic to human pancreatic carcinoma cells (AsPC-1) after thermal neutron irradiation in vitro. The intra-tumoural injection of boronated immunoliposomes can increase the retention of 10 B atoms in tumour cells, causing suppression of tumour growth in vivo following thermal neutron irradiation. We prepared polyethylene-glycol binding liposomes (PEG-liposomes) as an effective 10 B carrier to obviate phagocytosis by reticuloendotherial systems. We had prepared 10 BSH entrapped Water-in-Oil-in-Water (WOW) emulsion. The 10 B concentration in VX-2 tumour after intra-arterial injection of 10 BSH entrapped WOW emulsion was superior to the groups of 10 BSH entrapped conventional Lipiodol mix emulsion. 10 Boron entrapped WOW emulsion is one of the most useful for intra-arterial boron delivery carrier on BNCT to hepatocellular carcinoma. (author)

  3. Application of 10B entrapped PEG-liposome to boron neutron-capture therapy for pancreatic cancer model in vivo

    International Nuclear Information System (INIS)

    Yanagie, H.; Eriguchi, M.; Maruyama, K.; Takizawa, T.; Ishida, O.; Ogura, K.; Matsumoto, T.; Sakurai, Y.; Kobayashi, T.; Ono, K.; Rant, J.; Skvarc, J.; Ilic, R.; Shinohara, A.; Chiba, M.; Kobayashi, H.

    1999-01-01

    The cytotoxic effects for tumor were evaluated with intravenous injection 10 B PEG-liposome (Stealth liposome) on human pancreatic carcinoma wenografts in nude mice with thermal neutron irradiation. After thermal neutron irradiation of mice injected with 10 B bare-liposome or 10 B PEG liposome, AsPC-1 tumour growth was suppressed relative to controls. Injection of 10 B PEG-liposome caused the greatest tumour suppression with thermal neutron irradiation in vivo. These results suggest that intravenous injection of 10 B PEG-liposome can increase the retention of 10 B atoms by tumor cells, causing tumor growth suppression in vivo upon thermal neutron irradiation.(author)

  4. Hot flow behavior of boron microalloyed steels

    International Nuclear Information System (INIS)

    Lopez-Chipres, E.; Mejia, I.; Maldonado, C.; Bedolla-Jacuinde, A.; El-Wahabi, M.; Cabrera, J.M.

    2008-01-01

    This research work studies the effect of boron contents on the hot flow behavior of boron microalloyed steels. For this purpose, uniaxial hot-compression tests were carried out in a low carbon steel microalloyed with four different amounts of boron over a wide range of temperatures (950, 1000, 1050 and 1100 deg. C) and constant true strain rates (10 -3 , 10 -2 and 10 -1 s -1 ). Experimental results revealed that both peak stress and peak strain tend to decrease as boron content increases, which indicates that boron additions have a solid solution softening effect. Likewise, the flow curves show a delaying effect on the kinetics of dynamic recrystallization (DRX) when increasing boron content. Deformed microstructures show a finer austenitic grain size in the steel with higher boron content (grain refinement effect). Results are discussed in terms of boron segregation towards austenitic grain boundaries during plastic deformation, which increases the movement of dislocations, enhances the grain boundary cohesion and modificates the grain boundary structure

  5. Preliminary study on 2-dimensional distributions of 10B reaction rate in a water phantom with boron-doped CR-39 for 7Li(p, n)7Be neutrons by 1.95 MeV protons

    International Nuclear Information System (INIS)

    Hasegawa, Y.; Tanaka, K.; Tsuruta, T.

    2000-01-01

    In an Accelerator-based neutron irradiation field using 7 Li(p, n) 7 Be neutrons by 1.95 MeV protons, the distributions of 10 B reaction rates and thermal neutron fluence in a water phantom were measured using Boron-doped CR-39 and Au activation analysis, respectively. Comparing the results of the measurements, we discussed the validity of the evaluation method of 10 B reaction rate using thermal neutron fluence. (author)

  6. Boron analysis and boron imaging in biological materials for Boron Neutron Capture Therapy (BNCT).

    Science.gov (United States)

    Wittig, Andrea; Michel, Jean; Moss, Raymond L; Stecher-Rasmussen, Finn; Arlinghaus, Heinrich F; Bendel, Peter; Mauri, Pier Luigi; Altieri, Saverio; Hilger, Ralf; Salvadori, Piero A; Menichetti, Luca; Zamenhof, Robert; Sauerwein, Wolfgang A G

    2008-10-01

    Boron Neutron Capture Therapy (BNCT) is based on the ability of the stable isotope 10B to capture neutrons, which leads to a nuclear reaction producing an alpha- and a 7Li-particle, both having a high biological effectiveness and a very short range in tissue, being limited to approximately one cell diameter. This opens the possibility for a highly selective cancer therapy. BNCT strongly depends on the selective uptake of 10B in tumor cells and on its distribution inside the cells. The chemical properties of boron and the need to discriminate different isotopes make the investigation of the concentration and distribution of 10B a challenging task. The most advanced techniques to measure and image boron are described, both invasive and non-invasive. The most promising approach for further investigation will be the complementary use of the different techniques to obtain the information that is mandatory for the future of this innovative treatment modality.

  7. Methods of forming boron nitride

    Science.gov (United States)

    Trowbridge, Tammy L; Wertsching, Alan K; Pinhero, Patrick J; Crandall, David L

    2015-03-03

    A method of forming a boron nitride. The method comprises contacting a metal article with a monomeric boron-nitrogen compound and converting the monomeric boron-nitrogen compound to a boron nitride. The boron nitride is formed on the same or a different metal article. The monomeric boron-nitrogen compound is borazine, cycloborazane, trimethylcycloborazane, polyborazylene, B-vinylborazine, poly(B-vinylborazine), or combinations thereof. The monomeric boron-nitrogen compound is polymerized to form the boron nitride by exposure to a temperature greater than approximately 100.degree. C. The boron nitride is amorphous boron nitride, hexagonal boron nitride, rhombohedral boron nitride, turbostratic boron nitride, wurzite boron nitride, combinations thereof, or boron nitride and carbon. A method of conditioning a ballistic weapon and a metal article coated with the monomeric boron-nitrogen compound are also disclosed.

  8. Application of drug delivery system to boron neutron capture therapy for cancer.

    Science.gov (United States)

    Yanagië, Hironobu; Ogata, Aya; Sugiyama, Hirotaka; Eriguchi, Masazumi; Takamoto, Shinichi; Takahashi, Hiroyuki

    2008-04-01

    Tumor cell destruction in boron neutron capture therapy (BNCT) is due to the nuclear reaction between (10)B and thermal neutrons ((10)B + (1)n --> (7)Li + (4)He (alpha) + 2.31 MeV (93.7 %)/2.79 MeV (6.3 %)). The resulting lithium ions and alphaparticles are high linear energy transfer (LET) particles which give a high biological effect. Their short range in tissue (5 - 9 mum) restricts radiation damage to those cells in which boron atoms are located at the time of neutron irradiation. BNCT has been applied clinically for the treatment of malignant brain tumors, malignant melanoma, head and neck cancer and hepatoma. Sodium mercaptoundecahydro-dodecaborate (Na(2)(10)B(12)H(11)SH: BSH) and borono-phenylalanine ((10)BPA) are currently being used in clinical treatments. These low molecule compounds are easily cleared from cancer cells and blood, so high accumulation and selective delivery of boron compounds into tumor tissues and cancer cells are most important to achieve effective BNCT and to avoid damage to adjacent healthy cells. In order to achieve the selective delivery of boron atoms to cancer cells, a drug delivery system (DDS) is an attractive intelligent technology for targeting and controlled release of drugs. We performed literature searches related to boron delivery systems in vitro and in vivo. We describe several DDS technologies for boron delivery to cancer tissues and cancer cells from the past to current status. We are convinced that it will be possible to use liposomes, monoclonal antibodies and WOW emulsions as boron delivery systems for BNCT clinically in accordance with the preparation of good commercial product (GCP) grade materials.

  9. Proceedings of workshop on 'Boron Chemistry and Boron Neutron Capture Therapy'

    International Nuclear Information System (INIS)

    Kitaoka, Y.

    1991-07-01

    This volume contains the proceedings of the 3rd Workshop on 'the Boron Chemistry and Boron Neutron Capture Therapy' held on February 12, in 1991. In this workshop, our attention was focused on the chemical nature of boron compounds and the boron neutron capture therapy (BNCT). First, clinical experiences of BNCT in KURRI in 1990 and 1991 were reported (Chap. 3). The feasibility of the gadolinium neutron capture therapy for brain tumors was discussed (Chap. 4). In the chemical field, a rapid spectrophotometric determination of trace amounts of borons in biological samples is described (Chap. 5). The chemical behaviours of p-boronophenylalanine and its analogs in aqueous solutions were investigated by a paper electrophoresis and infrared spectroscopy (Chap. 6). On the molecular design and synthesis of new boron carriers for BNCT, several new synthetic methods for B-10 containing nucleoside derivatives were shown (Chap. 7). (author)

  10. Boron-enhanced diffusion of boron from ultralow-energy boron implantation

    International Nuclear Information System (INIS)

    Agarwal, A.; Eaglesham, D.J.; Gossmann, H.J.; Pelaz, L.; Herner, S.B.; Jacobson, D.C.

    1998-01-01

    The authors have investigated the diffusion enhancement mechanism of BED (boron enhanced diffusion), wherein the boron diffusivity is enhanced three to four times over the equilibrium diffusivity at 1,050 C in the proximity of a silicon layer containing a high boron concentration. It is shown that BED is associated with the formation of a fine-grain polycrystalline silicon boride phase within an initially amorphous Si layer having a high B concentration. For 0.5 keV B + , the threshold implantation dose which leads to BED lies between 3 x 10 14 and of 1 x 10 15 /cm -2 . Formation of the shallowest possible junctions by 0.5 keV B + requires that the implant dose be kept lower than this threshold

  11. Evaluation of the reduction of boron-10 in the control rods in the BWR of the Laguna Verde Central, through steady state calculations

    International Nuclear Information System (INIS)

    Montes T, J.L.; Perusquia, R.; Hernandez, J.L.; Ramirez S, J.R.

    2003-01-01

    One of the more important aspects related with the safety and economy in the operation of a nuclear power reactor, it is without a doubt the control of the reactivity. During the normal operation of a reactor of boiling water (BWR-Boiling Water Reactor), the control of the reactivity in the nucleus it is strongly determined by the efficiency of the control rods. In the case of the Laguna Verde Nuclear power station (CNLV) the nucleus of the reactors has 109 control rods grouped in 4 sets. The CNLV at the moment uses the CCC method (Control Cell Core) in the design of the cycle. With this method only the A2 group is used for the control of the reactivity at full power. With the purpose of quantifying the effect of the decrease of the burnable poison (B 4 C) of the control rods and in particular to the effect due to the postulated lost of 10% of Boron 10, it was carried out a series of calculations of the nucleus in stationary state by means of the system of HELIOS/CM-PRESTO codes. In this work the main derived results of these 3D simulations(three dimensions) of the reactors of the CNLV are presented. It was analyzed the one behavior of the infinite neutron multiplication factor (K infinite ), at fuel assemble cell level used in an equilibrium cycle for the CNLV. It was also analyzed the effect in the shutdown margin (ShutDown Margin- SDM) in cold condition CZP (Cold Zero Power). Its are also included those results of the ARI cases (All Rods In) and SRO (Strong Rod Out). From the cases in condition HFP (Hot Full Power) the behavior of the effective multiplication factor (K eff ) is presented. (Author)

  12. Proceedings of workshop on 'boron science and boron neutron capture therapy'

    Energy Technology Data Exchange (ETDEWEB)

    Kitaoka, Y. [ed.

    1998-12-01

    This volume contains the abstracts and programs of the 8th (1996), 9th (1997) and 10th (1998) of the workshop on 'the Boron Science and Boron Neutron Capture Therapy' and the recent progress reports especially subscribed. The 11 of the presented papers are indexed individually. (J.P.N.)

  13. New Pathways and Metrics for Enhanced, Reversible Hydrogen Storage in Boron-Doped Carbon Nanospaces

    Energy Technology Data Exchange (ETDEWEB)

    Pfeifer, Peter [University of Missouri; Wexler, Carlos [University of Missouri; Hawthorne, M. Frederick [University of Missouri; Lee, Mark W. [University of Missouri; Jalistegi, Satish S. [University of Missouri

    2014-08-14

    This project, since its start in 2007—entitled “Networks of boron-doped carbon nanopores for low-pressure reversible hydrogen storage” (2007-10) and “New pathways and metrics for enhanced, reversible hydrogen storage in boron-doped carbon nanospaces” (2010-13)—is in support of the DOE's National Hydrogen Storage Project, as part of the DOE Hydrogen and Fuel Cells Program’s comprehensive efforts to enable the widespread commercialization of hydrogen and fuel cell technologies in diverse sectors of the economy. Hydrogen storage is widely recognized as a critical enabling technology for the successful commercialization and market acceptance of hydrogen powered vehicles. Storing sufficient hydrogen on board a wide range of vehicle platforms, at energy densities comparable to gasoline, without compromising passenger or cargo space, remains an outstanding technical challenge. Of the main three thrust areas in 2007—metal hydrides, chemical hydrogen storage, and sorption-based hydrogen storage—sorption-based storage, i.e., storage of molecular hydrogen by adsorption on high-surface-area materials (carbons, metal-organic frameworks, and other porous organic networks), has emerged as the most promising path toward achieving the 2017 DOE storage targets of 0.055 kg H2/kg system (“5.5 wt%”) and 0.040 kg H2/liter system. The objective of the project is to develop high-surface-area carbon materials that are boron-doped by incorporation of boron into the carbon lattice at the outset, i.e., during the synthesis of the material. The rationale for boron-doping is the prediction that boron atoms in carbon will raise the binding energy of hydro- gen from 4-5 kJ/mol on the undoped surface to 10-14 kJ/mol on a doped surface, and accordingly the hydro- gen storage capacity of the material. The mechanism for the increase in binding energy is electron donation from H2 to electron-deficient B atoms, in the form of sp2 boron-carbon bonds. Our team is proud to have

  14. Boron nitride converted carbon fiber

    Science.gov (United States)

    Rousseas, Michael; Mickelson, William; Zettl, Alexander K.

    2016-04-05

    This disclosure provides systems, methods, and apparatus related to boron nitride converted carbon fiber. In one aspect, a method may include the operations of providing boron oxide and carbon fiber, heating the boron oxide to melt the boron oxide and heating the carbon fiber, mixing a nitrogen-containing gas with boron oxide vapor from molten boron oxide, and converting at least a portion of the carbon fiber to boron nitride.

  15. Apparatus for the production of boron nitride nanotubes

    Science.gov (United States)

    Smith, Michael W; Jordan, Kevin

    2014-06-17

    An apparatus for the large scale production of boron nitride nanotubes comprising; a pressure chamber containing; a continuously fed boron containing target; a source of thermal energy preferably a focused laser beam; a cooled condenser; a source of pressurized nitrogen gas; and a mechanism for extracting boron nitride nanotubes that are condensed on or in the area of the cooled condenser from the pressure chamber.

  16. A simple ratiometric fluorescent sensor for fructose based on complexation of 10-hydroxybenzo[h]quinoline with boronic acid

    Science.gov (United States)

    Li, Huihui; Yang, Cailing; Zhu, Xinyue; Zhang, Haixia

    2017-06-01

    A simple ratiometric fluorescent sensor for fructose was presented. It consisted of 10-hydroxybenzo[h]quinoline (HBQ) which showed emission at 572 nm and 3-pyridylboronic acid (PDBA) whose complex with HBQ gave emission at 500 nm. The reaction of fructose with PDBA inhibited the complexation of HBQ with PDBA, resulting in the change of dual-emission intensity ratio. The sensor well quantified fructose in the range of 0.015-2.5 mM with detection limit of 0.005 mM. Besides, this sensor exhibited excellent selectivity and was successfully applied to fructose detection in food. This work provides a simple ratiometric sensing platform for sensitive and selective detection of fructose.

  17. Radiological analysis of plutonium glass batches with natural/enriched boron

    International Nuclear Information System (INIS)

    Rainisch, R.

    2000-01-01

    The disposition of surplus plutonium inventories by the US Department of Energy (DOE) includes the immobilization of certain plutonium materials in a borosilicate glass matrix, also referred to as vitrification. This paper addresses source terms of plutonium masses immobilized in a borosilicate glass matrix where the glass components include both natural boron and enriched boron. The calculated source terms pertain to neutron and gamma source strength (particles per second), and source spectrum changes. The calculated source terms corresponding to natural boron and enriched boron are compared to determine the benefits (decrease in radiation source terms) for to the use of enriched boron. The analysis of plutonium glass source terms shows that a large component of the neutron source terms is due to (a, n) reactions. The Americium-241 and plutonium present in the glass emit alpha particles (a). These alpha particles interact with low-Z nuclides like B-11, B-10, and O-17 in the glass to produce neutrons. The low-Z nuclides are referred to as target particles. The reference glass contains 9.4 wt percent B 2 O 3 . Boron-11 was found to strongly support the (a, n) reactions in the glass matrix. B-11 has a natural abundance of over 80 percent. The (a, n) reaction rates for B-10 are lower than for B-11 and the analysis shows that the plutonium glass neutron source terms can be reduced by artificially enriching natural boron with B-10. The natural abundance of B-10 is 19.9 percent. Boron enriched to 96-wt percent B-10 or above can be obtained commercially. Since lower source terms imply lower dose rates to radiation workers handling the plutonium glass materials, it is important to know the achievable decrease in source terms as a result of boron enrichment. Plutonium materials are normally handled in glove boxes with shielded glass windows and the work entails both extremity and whole-body exposures. Lowering the source terms of the plutonium batches will make the handling

  18. Determination of boron concentration in biopsy-sized tissue samples

    International Nuclear Information System (INIS)

    Hou, Yougjin; Fong, Katrina; Edwards, Benjamin; Autry-Conwell, Susan; Boggan, James

    2000-01-01

    Inductively coupled plasma mass spectrometry (ICP-MS) is the most sensitive analytical method for boron determination. However, because boron is volatile and ubiquitous in nature, low-concentration boron sample measurement remains a challenge. In this study, an improved ICP-MS method was developed for quantitation of tissue samples with low (less than 10 ppb) and high (100 ppb) boron concentrations. The addition of an ammonia-mannitol solution converts volatile boric acid to the non-volatile ammonium borate in the spray chamber and with the formation of a boron-mannitol complex, the boron memory effect and background are greatly reduced. This results in measurements that are more accurate, repeatable, and efficient. This improved analysis method has facilitated rapid and reliable tissue biodistribution analyses of newly developed boronated compounds for potential use in neutron capture therapy. (author)

  19. Density separation of boron particles. Final report

    International Nuclear Information System (INIS)

    Smith, R.M.

    1980-04-01

    A density distribution much broader than expected was observed in lots of natural boron powder supplied by two different sources. The material in both lots was found to have a rhombohedral crystal structure, and the only other parameters which seemed to account for such a distribution were impurities within the crystal structure and varying isotopic ratios. A separation technique was established to isolate boron particles in narrow densty ranges. The isolated fractions were subsequently analyzed for B 10 and total boron content in an effort to determine whether selective isotopic enrichment and nonhomogeneous impurity distribution were the causes for the broad density distribution of the boron powders. It was found that although the B 10 content remained nearly constant around 18%, the total boron content varied from 37.5 to 98.7%. One of the lots also was found to contain an apparently high level of alpha rhombohedral boron which broadened the density distribution considerably. During this work, a capability for removing boron particles containing gross amounts of impurities and, thereby, improving the overall purity of the remaining material was developed. In addition, the separation technique used in this study apparently isolated particles with alpha and beta rhombohedral crystal structures, although the only supporting evidence is density data

  20. Spectromicroscopy in Boron Neutron Capture Therapy Research

    Science.gov (United States)

    Gilbert, Benjamin; Redondo, Jose; Andres, Roger; Suda, Takashi; Neumann, Michael; Steen, Steffi; Gabel, Detlef; Mercanti, Delio; Ciotti, Teresa; Perfetti, Paolo; Margaritondo, Giorgio; de Stasio, Gelsomina

    1998-03-01

    The MEPHISTO synchrotron imaging spectromicroscope can analyse ashed cells or tissue sections to reveal the microdistribution of trace elements. MEPHISTO performs core level x-ray absorption spectroscopy with synchrotron radiation, and uses an electron optics system to provide magnified photoelectron images. An application of the MEPHISTO spectromicroscope is in boron neutron capture therapy (BNCT). BNCT is a binary cancer therapy that will selectively destroy cancer cells provided that compounds containing a boron isotope are selectively accumulated in tumor tissue. Important factors for the success of BNCT include the ability to target every cancer cell, and the distribution of boron inside the cell. To investigate the boron distribution in tissue, sections of human glioblastoma containing a BNCT compound, and stained with nickel against a protein found in the nuclei of proliferating (cancer) cells, were studied with MEPHISTO.

  1. Boron nanoparticles inhibit turnour growth by boron neutron capture therapy in the murine B16-OVA model

    DEFF Research Database (Denmark)

    Petersen, Mikkel Steen; Petersen, Charlotte Christie; Agger, Ralf

    2008-01-01

    Background: Boron neutron capture therapy usually relies on soluble, rather than particulate, boron compounds. This study evaluated the use of a novel boron nanoparticle for boron neutron capture therapy. Materials and Methods: Two hundred and fifty thousand B16-OVA tumour cells, pre......-incubated with boron nanoparticles for 12 hours, were injected subcutaneously into C57BL16J mice. The tumour sites were exposed to different doses of neutron radiation one, four, or eight days after tumour cell inoculation. Results: When the tumour site was irradiated with thermal neutrons one day after injection......, tumour growth was delayed and the treated mice survived longer than untreated controls (median survival time 20 days (N=8) compared with 10 days (N=7) for untreated mice). Conclusion: Boron nanoparticles significantly delay the growth of an aggressive B16-OVA tumour in vivo by boron neutron capture...

  2. Utilization of Boron (10B derived from fertilizer by sugar cane Aproveitamento do Boro (10B proveniente do fertilizante pela cana-de-açúcar

    Directory of Open Access Journals (Sweden)

    Henrique Coutinho Junqueira Franco

    2009-12-01

    Full Text Available The response to B in agricultural systems of sugar cane is still an unexplored issue; B application has however recently been widely publicized and used with a certain degree of frequency. The use of 10B-labeled fertilizers may further contribute to clarify this practice. With the objective of evaluating sugar cane use of B (10B derived from fertilizer (boric acid, an experiment was conducted under field conditions in the 2005/2006 growing season. The experiment consisted of the installation of microplots (2 x 1.5 m where 4 kg ha-1 B (boric acid with 85.95 % in 10B atoms dissolved in water was applied 90 days after planting (May 2005. The solution was applied to the soil on both sides of the plant row at a distance of 20 cm. After harvest (June 2006 the B content and 10B abundance in % atoms in all parts of the sugar cane plants (stalks, dry leaves, tips and roots were determined. Results showed that the total B accumulated was 471 g ha-1 in the entire plant (35 % in the stalks, 22 % in the dry leaves, 9 % in the tips and 34 % in the roots. The sugar cane plants used on average 14 % of the total accumulated B in the above-ground part (44 g ha-1 and 11 % in the roots (19 g ha-1, totaling 13 % in the entire plant (63 g ha-1. The recovery of 10B-fertilizer by sugar cane plants was low, around 2 % of the total applied amount.No agrossistema da cana-de-açúcar a resposta à aplicação de B é ainda uma questão não esclarecida, porém é um procedimento que vem sendo utilizado com certa frequência. O uso de fertilizantes marcados com 10B pode auxiliar no entendimento dessa prática. Com o objetivo de avaliar o aproveitamento do B (10B proveniente do fertilizante (ácido bórico pela cana-de-açúcar, realizou-se um experimento em campo, na safra de 2005/2006, que consistiu na instalação de microparcelas (2 m de comprimento por 1,5 de largura, que, após 90 dias do plantio (maio de 2005, receberam 4 kg ha-1 de B (ácido bórico com 85,95 % em

  3. B-decachloro-o-carborane derivatives as suitable boron carriers for the preparation of water-soluble boron-conjugated macromolecules

    International Nuclear Information System (INIS)

    Gabel, D.; Walczyna, R.; Wellmann, F.; Riesenberg, H.; Hocke, I.

    1982-01-01

    The preparation of boron-containing macromolecules, especially immunoglobulins, for boron neutron capture therapy, has so far been rather unsuccessful, because of the increased water insolubility of heavily substituted proteins. By using polar boron compounds, some of the difficulties previously encountered in the preparation of boron-conjugated immunoglobulins might be overcome. To this end, the authors have investigated the use of B-decachloro-o-carborane (B 10 Cl 10 C 2 H 2 ) for the preparation of water-soluble macromolecules

  4. Biological evaluation of boronated unnatural amino acids as new boron carriers

    Energy Technology Data Exchange (ETDEWEB)

    Kabalka, G.W. [Departments of Radiology and Chemistry, University of Tennessee, Knoxville, TN (United States)], E-mail: kabalka@utk.edu; Yao, M.-L.; Marepally, S.R. [Departments of Radiology and Chemistry, University of Tennessee, Knoxville, TN (United States); Chandra, S. [Cornell SIMS Laboratory, Department of Earth and Atmospheric Sciences, Snee Hall, Cornell University, Ithaca, NY (United States)

    2009-07-15

    There is a pressing need for new and more efficient boron delivery agents to tumor cells for use in boron neutron capture therapy (BNCT). A class of boronated unnatural cyclic amino acids has demonstrated a remarkable selectivity toward tumors in animal and cell culture models, far superior to currently used agents in clinical BNCT. One of these amino acids, 1-amino-3-boronocyclopentanecarboxylic acid (ABCPC), has shown a tumor to blood ratio of 8 and a tumor to normal brain ratio of nearly 21 in a melanoma bearing mouse model. This work represents further biological characterization of this compound for tumor targeting in an EMT6 murine mammary carcinoma mouse model and a T98G human glioblastoma cell line. Female BALB/c mice bearing EMT6 tumors were injected with the fructose complex form of racemic mixtures of cis and trans isomers of ABCPC in identical concentrations. Boron concentrations were measured in the tumor, blood, brain, skin, and liver tissues at 1, 3, and 5 h post-injection. These observations revealed a remarkable difference in racemic mixtures of cis and trans isomers in tumor targeting by boron. This implies that further separation of the L and D forms of this compound may enhance tumor targeting to an even higher degree than that provided by the racemic mixtures. Since the uptake measurements were made in homogenized tumor and normal tissues, little is known about the subcellular location of the boron arising from the various isomeric forms of the amino acid. To study subcellular delivery of boron from ABCPC in T98G human glioblastoma cells, we employed secondary ion mass spectrometry (SIMS) based technique of ion microscopy, which is capable of quantitatively imaging isotopic (elemental) gradients in cells and tissues at 500 nm spatial resolution. The T98G cells were exposed to the nutrient medium containing 100 ppm boron equivalent of a mixture of both L and D isomers of ABCPC in the form of a fructose complex for 1 h. Following this treatment

  5. Biological Evaluation of Boronated Unnatural Amino Acids as New Boron Carriers

    Science.gov (United States)

    Kabalka, G.W.; Yao, M.-L.; Marepally, S.R.; Chandra, S.

    2010-01-01

    There is a pressing need for new and more efficient boron delivery agents to tumor cells for use in boron neutron capture therapy (BNCT). A class of boronated unnatural cyclic amino acids has demonstrated a remarkable selectivity toward tumors in animal and cell culture models, far superior to currently used agents in clinical BNCT. One of these amino acids, 1-amino-3-boronocyclopentanecarboxylic acid (ABCPC), has shown a tumor to blood ratio of 8 and a tumor to normal brain ratio of nearly 21 in a melanoma bearing mouse model. This work represents further biological characterization of this compound for tumor targeting in an EMT6 murine mammary carcinoma mouse model and a T98G human glioblastoma cell line. Female BALB/c mice bearing EMT6 tumors were injected with the fructose complex form of racemic mixtures of cis- and trans isomers of ABCPC in identical concentrations. Boron concentrations were measured in the tumor, blood, brain, skin, and liver tissues at 1, 3, and 5 hr post injection. These observations revealed a remarkable difference in racemic mixtures of cis and trans isomers in tumor targeting by boron. This implies that further separation of the L and D forms of this compound may enhance tumor targeting to an even higher degree than that provided by the racemic mixtures. Since the uptake measurements were made in homogenized tumor and normal tissues, little is known about the subcellular location of the boron arising from the various isomeric forms of the amino acid. To study subcellular delivery of boron from ABCPC in T98G human glioblastoma cells, we employed secondary ion mass spectrometry (SIMS) based technique of ion microscopy, which is capable of quantitatively imaging isotopic (elemental) gradients in cells and tissues at 500 nm spatial resolution. The T98G cells were exposed to the nutrient medium containing 100 ppm boron equivalent of a mixture of both L and D isomers of ABCPC in the form of a fructose complex for 1 hr. Following this

  6. Boron exposure through drinking water during pregnancy and birth size.

    Science.gov (United States)

    Igra, Annachiara Malin; Harari, Florencia; Lu, Ying; Casimiro, Esperanza; Vahter, Marie

    2016-10-01

    Boron is a metalloid found at highly varying concentrations in soil and water. Experimental data indicate that boron is a developmental toxicant, but the few human toxicity data available concern mostly male reproduction. To evaluate potential effects of boron exposure through drinking water on pregnancy outcomes. In a mother-child cohort in northern Argentina (n=194), 1-3 samples of serum, whole blood and urine were collected per woman during pregnancy and analyzed for boron and other elements to which exposure occurred, using inductively coupled plasma mass spectrometry. Infant weight, length and head circumference were measured at birth. Drinking water boron ranged 377-10,929μg/L. The serum boron concentrations during pregnancy ranged 0.73-605μg/L (median 133μg/L) and correlated strongly with whole-blood and urinary boron, and, to a lesser extent, with water boron. In multivariable-adjusted linear spline regression analysis (non-linear association), we found that serum boron concentrations above 80μg/L were inversely associated with birth length (B-0.69cm, 95% CI -1.4; -0.024, p=0.043, per 100μg/L increase in serum boron). The impact of boron appeared stronger when we restricted the exposure to the third trimester, when the serum boron concentrations were the highest (0.73-447μg/L). An increase in serum boron of 100μg/L in the third trimester corresponded to 0.9cm shorter and 120g lighter newborns (p=0.001 and 0.021, respectively). Considering that elevated boron concentrations in drinking water are common in many areas of the world, although more screening is warranted, our novel findings warrant additional research on early-life exposure in other populations. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. New approaches to novel boronated porphyrins for neutron capture therapy

    International Nuclear Information System (INIS)

    Kahl, S.B.

    1986-01-01

    The use of boon compounds in the treatment of human cancer is based on the unique ability of nonradioactive 10 B nuclei to absorb thermal neutrons. The prompt nuclear reactions, which occur in neutron absorption, deliver a dose of nearly 2.8 MeV only in the vicinity of boron-containing cells, since the nuclear garments produced (alpha particles and recoil lithium atoms) travel only 10 to 15 μm. The practical, clinical use of this technique to date has been limited by the authors inability to target boron-containing compounds specifically to tumor cells in amounts sufficient for therapy and in a chemical form that has an acceptable level of toxicity. Porphyrins are one important and large class of compounds that are known to accumulate in practically all tumor systems yet examined. Such site-specific accumulation is not known to be based on any currently identifiable selective transport mechanism and yet is observed for both natural and synthetic porphyrins. Tetraphenylporphine sulfonate (TPPS) has been shown by Fairchild et al. to be an ideal model compound for assessing porphyrin uptake, and suitably boronated tetraphenyl porphine might be expected to behave similarly. This report describes the synthesis, properties, and preliminary biodistribution of such compounds

  8. Laser-induced photochemical enrichment of boron isotopes

    International Nuclear Information System (INIS)

    Freund, S.M.; Ritter, J.J.

    1976-01-01

    A boron trichloride starting material containing both boron-10 isotopes and boron-11 isotopes is selectively enriched in one or the other of these isotopes by a laser-induced photochemical method involving the reaction of laser-excited boron trichloride with either H 2 S or D 2 S. The method is carried out by subjecting a low pressure gaseous mixture of boron trichloride starting material and the sulfide to infrared radiation from a carbon dioxide TE laser. The wave length of the radiation is selected so as to selectively excite one or the other of boron-10 BCl 3 molecules or boron-11 BCl 3 molecules, thereby making them preferentially more reactive with the sulfide. The laser-induced reaction produces both a boron-containing solid phase reaction product and a gaseous phase containing mostly unreacted BCl 3 and small amounts of sulfhydroboranes. Pure boron trichloride selectively enriched in one of the isotopes is recovered as the primary product of the method from the gaseous phase by a multi-step recovery procedure. Pure boron trichloride enriched in the other isotope is recovered as a secondary product of the method by the subsequent chlorination of the solid phase reaction product followed by separation of BCl 3 from the mixture of gaseous products resulting from the chlorination

  9. Boron carbide coating deposition on tungsten substrates from atomic fluxes of boron and carbon

    Science.gov (United States)

    Sadovskiy, Y.; Begrambekov, L.; Ayrapetov, A.; Gretskaya, I.; Grunin, A.; Dyachenko, M.; Puntakov, N.

    2016-09-01

    A device used for both coating deposition and material testing is presented in the paper. By using lock chambers, sputtering targets are easily exchanged with sample holder thus allowing testing of deposited samples with high power density electron or ion beams. Boron carbide coatings were deposited on tungsten samples. Methods of increasing coating adhesion are described in the paper. 2 μm boron carbide coatings sustained 450 heating cycles from 100 to 900 C. Ion beam tests have shown satisfactory results.

  10. Quantitative boron detection by neutron transmission method

    International Nuclear Information System (INIS)

    Okka, M.; Genceli, M.; Eren, E.; Bayulken, A.

    2008-01-01

    //Quantitative boron detection is mainly performed by chemical methods like colorimetric titration. High neutron absorption cross section of natural boron makes attractive its detection by absorption measurements. This work is an extension of earlier investigations where neutron radiography technique was used for boron detection. In the present investigation, the neutron absorption rate of boron containing solutions is the way to measure quantitatively the boron content of the solutions. The investigation was carried out in Istanbul TRIGA Mark-II reactor. In the end of the experiments, it was observed that even |ppw| grade boron in aqueous solution can be easily detected. The use of this method is certainly very useful for boron utilizing industries like glass and steel industries.The major disadvantage of the method is the obligation to use always aqueous solutions to be able to detect homogeneously the boron content. Then, steel or glass samples have to be put first in an appropriate solution form. The irradiation of steel samples can give the distribution of boron by the help of a imaging and this suggested method will give its quantitative measurement. The superiority of this method are its quick response time and its accuracy. To test this accuracy, a supposed unknown , solution of boric acid is irradiated and then calculated by the help of the calibration curve. The measured value of boric acid was 0.89 mg and the calculated value was found to be 0.98 mg which gives an accuracy of 10 %. It was also seen that the method is more accurate for low concentration. (authors)

  11. Boron Isotope Compositions of Selected Fresh MORB Glasses From the Northern EPR (8-10° N): Implications for MORB Magma Contamination

    Science.gov (United States)

    Le Roux, P. J.; Shirey, S. B.; Hauri, E. H.; Perfit, M. R.

    2003-12-01

    . These MORB samples have 0.56 to 2.61 ppm B, and B isotope compositions that are surprisingly restricted ranging from δ 11B -5.50 to -8.96‰ . The low δ 11B values are close to the depleted upper mantle value (-10‰ ). The δ 11B data do not correlation with B concentrations, Mg#, Sr, Nd or Pb isotopes, or proxies for brine addition (e.g. Cl/Nb). The lowest δ 11B samples are also the most-incompatible element depleted (high B/Nb ratios). The δ 11B of the on-axis samples increases slightly with increased levels of magma degassing (i.e. lowest δ 11B values in samples extracted undegassed from depths closest to AMC top).Therefore, although the Cl data indicate significant addition of probably a saline brine component to both on- and off-axis MORB magmas, their δ 11B compositions were not significantly affected by this process and the observed variations in δ 11B may have a different origin. Possibly, the low B/Cl ratio of seawater ( ˜ 0.001) coupled with preferential partitioning of Cl relative to B into brines during supercritical phase separation (Berndt and Seyfried, 1990) of seawater in hydrothermal system, results in very saline brines with low boron concentrations. The coupled B-Cl data effectively eliminates simple magmatic assimilation of altered Cl-rich high-B isotope composition oceanic crust in this region.

  12. Boron precipitates in ion implanted silicon

    International Nuclear Information System (INIS)

    Wu, W.K.; Washburn, J.

    1975-03-01

    Long rod-like defects are observed in ion implanted silicon when boron is present either as a prior dopant addition or as the implanted species. Results of recent work indicates that these defects have the characteristics of narrow extrinsic dipoles or elongated dislocation loops and that there are two different types along each of the six (110) directions. An annealing kinetics method has been used to identify the nature of these defects formed during post-implantation annealing in boron ion (100 keV) implanted silicon irradiated at room temperature to a dose of 2 x 10 14 /cm 2 . It is concluded that at least two different kinds of rod-like defects exist in boron ion implanted silicon. From the activation energy for shrinkage, it is also concluded that one type (anti A) is composed largely of boron atoms. (U.S.)

  13. Isotopic effects on the phonon modes in boron carbide.

    Science.gov (United States)

    Werheit, H; Kuhlmann, U; Rotter, H W; Shalamberidze, S O

    2010-10-06

    The effect of isotopes ((10)B-(11)B; (12)C-(13)C) on the infrared- and Raman-active phonons of boron carbide has been investigated. For B isotopes, the contributions of the virtual crystal approximation, polarization vector and isotopical disorder are separated. Boron and carbon isotope effects are largely opposite to one another and indicate the share of the particular atoms in the atomic assemblies vibrating in specific phonon modes. Some infrared-active phonons behave as expected for monatomic boron crystals.

  14. Synthesis and characterization of boron fenbufen and its F-18 labeled homolog for boron neutron capture therapy of COX-2 overexpressed cholangiocarcinoma.

    Science.gov (United States)

    Yeh, Chun-Nan; Chang, Chi-Wei; Chung, Yi-Hsiu; Tien, Shi-Wei; Chen, Yong-Ren; Chen, Tsung-Wen; Huang, Ying-Cheng; Wang, Hsin-Ell; Chou, You-Cheng; Chen, Ming-Huang; Chiang, Kun-Chun; Huang, Wen-Sheng; Yu, Chung-Shan

    2017-09-30

    Boron neutron capture therapy (BNCT) is a binary therapy that employs neutron irradiation on the boron agents to release high-energy helium and alpha particles to kill cancer cells. An optimal response to BNCT depends critically on the time point of maximal 10 B accumulation and highest tumor to normal ratio (T/N) for performing the neutron irradiation. The aggressive cholangiocarcinoma (CCA) representing a liver cancer that overexpresses COX-2 enzyme is aimed to be targeted by COX-2 selective boron carrier, fenbufen boronopinacol (FBPin). Two main works were performed including: 1) chemical synthesis of FBPin as the boron carrier and 2) radiochemical labeling with F-18 to provide the radiofluoro congener, m-[ 18 F]fluorofenbufen ester boronopinacol (m-[ 18 F]FFBPin), to assess the binding affinity, cellular accumulation level and distribution profile in CCA rats. FBPin was prepared from bromofenbufen via 3 steps with 82% yield. The binding assay employed [ 18 F]FFBPin to compete FBPin for binding to COX-1 (IC 50 =0.91±0.68μM) and COX-2 (IC 50 =0.33±0.24μM). [ 18 F]FFBPin-derived 60-min dynamic PET scans predict the 10 B-accumulation of 0.8-1.2ppm in liver and 1.2-1.8ppm in tumor and tumor to normal ratio=1.38±0.12. BNCT was performed 40-55min post intravenous administration of FBPin (20-30mg) in the CCA rats. CCA rats treated with BNCT display more tumor reduction than that by NCT with respect of 2-[ 18 F]fluoro-2-deoxy glucose uptake in the tumor region of interest, 20.83±3.00% (n=12) vs. 12.83±3.79% (n=10), P=0.05. The visualizing agent [ 18 F]FFBPin resembles FBPin to generate the time-dependent boron concentration profile. Optimal neutron irradiation period is thus determinable for BNCT. A boron-substituted agent based on COX-2-binding features has been prepared. The moderate COX-2/COX-1 selectivity index of 2.78 allows a fair tumor selectivity index of 1.38 with a mild cardiovascular effect. The therapeutic effect from FBPin with BNCT warrants a proper

  15. Integrated Rig for the Production of Boron Nitride Nanotubes via the Pressurized Vapor-Condenser Method

    Science.gov (United States)

    Smith, Michael W. (Inventor); Jordan, Kevin C. (Inventor)

    2014-01-01

    An integrated production apparatus for production of boron nitride nanotubes via the pressure vapor-condenser method. The apparatus comprises: a pressurized reaction chamber containing a continuously fed boron containing target having a boron target tip, a source of pressurized nitrogen and a moving belt condenser apparatus; a hutch chamber proximate the pressurized reaction chamber containing a target feed system and a laser beam and optics.

  16. High-power electron beam tests of a liquid-lithium target and characterization study of (7)Li(p,n) near-threshold neutrons for accelerator-based boron neutron capture therapy.

    Science.gov (United States)

    Halfon, S; Paul, M; Arenshtam, A; Berkovits, D; Cohen, D; Eliyahu, I; Kijel, D; Mardor, I; Silverman, I

    2014-06-01

    A compact Liquid-Lithium Target (LiLiT) was built and tested with a high-power electron gun at Soreq Nuclear Research Center (SNRC). The target is intended to demonstrate liquid-lithium target capabilities to constitute an accelerator-based intense neutron source for Boron Neutron Capture Therapy (BNCT) in hospitals. The lithium target will produce neutrons through the (7)Li(p,n)(7)Be reaction and it will overcome the major problem of removing the thermal power >5kW generated by high-intensity proton beams, necessary for sufficient therapeutic neutron flux. In preliminary experiments liquid lithium was flown through the target loop and generated a stable jet on the concave supporting wall. Electron beam irradiation demonstrated that the liquid-lithium target can dissipate electron power densities of more than 4kW/cm(2) and volumetric power density around 2MW/cm(3) at a lithium flow of ~4m/s, while maintaining stable temperature and vacuum conditions. These power densities correspond to a narrow (σ=~2mm) 1.91MeV, 3mA proton beam. A high-intensity proton beam irradiation (1.91-2.5MeV, 2mA) is being commissioned at the SARAF (Soreq Applied Research Accelerator Facility) superconducting linear accelerator. In order to determine the conditions of LiLiT proton irradiation for BNCT and to tailor the neutron energy spectrum, a characterization of near threshold (~1.91MeV) (7)Li(p,n) neutrons is in progress based on Monte-Carlo (MCNP and Geant4) simulation and on low-intensity experiments with solid LiF targets. In-phantom dosimetry measurements are performed using special designed dosimeters based on CR-39 track detectors. © 2013 Elsevier Ltd. All rights reserved.

  17. Nothing Boring About Boron

    Science.gov (United States)

    Pizzorno, Lara

    2015-01-01

    The trace mineral boron is a micronutrient with diverse and vitally important roles in metabolism that render it necessary for plant, animal, and human health, and as recent research suggests, possibly for the evolution of life on Earth. As the current article shows, boron has been proven to be an important trace mineral because it (1) is essential for the growth and maintenance of bone; (2) greatly improves wound healing; (3) beneficially impacts the body’s use of estrogen, testosterone, and vitamin D; (4) boosts magnesium absorption; (5) reduces levels of inflammatory biomarkers, such as high-sensitivity C-reactive protein (hs-CRP) and tumor necrosis factor α (TNF-α); (6) raises levels of antioxidant enzymes, such as superoxide dismutase (SOD), catalase, and glutathione peroxidase; (7) protects against pesticide-induced oxidative stress and heavy-metal toxicity; (8) improves the brains electrical activity, cognitive performance, and short-term memory for elders; (9) influences the formation and activity of key biomolecules, such as S-adenosyl methionine (SAM-e) and nicotinamide adenine dinucleotide (NAD+); (10) has demonstrated preventive and therapeutic effects in a number of cancers, such as prostate, cervical, and lung cancers, and multiple and non-Hodgkin’s lymphoma; and (11) may help ameliorate the adverse effects of traditional chemotherapeutic agents. In none of the numerous studies conducted to date, however, do boron’s beneficial effects appear at intakes > 3 mg/d. No estimated average requirements (EARs) or dietary reference intakes (DRIs) have been set for boron—only an upper intake level (UL) of 20 mg/d for individuals aged ≥ 18 y. The absence of studies showing harm in conjunction with the substantial number of articles showing benefits support the consideration of boron supplementation of 3 mg/d for any individual who is consuming a diet lacking in fruits and vegetables or who is at risk for or has osteopenia; osteoporosis

  18. Development of a Boron Neutron Capture Enhanced Fast Neutron Therapy Beam

    Energy Technology Data Exchange (ETDEWEB)

    Sweezy, Jeremy Ed [Georgia Tech

    2002-01-01

    The combination of fast neutron therapy and boron neutron capture therapy is currently under investigation at several fast neutron therapy centers worldwide. This treatment method, termed boron neutron capture enhanced fast neutron therapy (BNCEFNT) utilizes a boron containing drug to selectively increase the dose to the target tumor. BNCEFNT may be useful in the treatment of some radioresistant brain tumors, such as glioblastoma multiforme. A neutron therapy beam for boron neutron capture enhanced fast neutron therapy has been developed for the existing Fermilab Neutron Therapy Facility. This beam produces a significant dose enhancement due to the the boron neutron capture reaction. The beam was developed by designing a filter and collimator system using the Monte Carlo radiation transport code, MCNPX. The MCNPX code was benchmarked against depth-dose measurements of the standard treatment beam. The new BNCEFNT beam is filtered with 18.3-cm of low carbon steel and is collimated with steel. Measurements of the dose enhancement of the new BNCEFNT beam were performed with paired tissue equivalent ion chambers. One of the ion chambers has boron incorporated in the wall of the chamber to measure the dose due to boron neutron capture. The measured boron dose enhancement of the BNCEFNT beam is (16.3 ± 2.6)% per 100-ppm 10B for a 20-cm diameter beam and (10.0 ± 1.6)% per 100-ppm 10B for a 10-cm diameter beam. The dose rate of the new beam is reduced to 4.4% of the dose rate of the standard treatment beam. xxi A conceptual design that overcomes the reduced dose rate is also presented. This design uses a tungsten collimator placed near the patient, with a 1.5-cm tungsten filter just upstream of the collimator. Using graphite moderation of neutrons around the patient a percent dose enhancement of 15% can be attained with good collimation, for field sizes as small as 5 × 5 cm2 , and without a reduction in dose rate.

  19. Boron neutron capture therapy of malignant brain tumors at the Brookhaven Medical Research Reactor

    International Nuclear Information System (INIS)

    Joel, D.D.; Coderre, J.A.; Chanana, A.D.

    1996-01-01

    Boron neutron capture therapy (BNCT) is a bimodal form of radiation therapy for cancer. The first component of this treatment is the preferential localization of the stable isotope 10 B in tumor cells by targeting with boronated compounds. The tumor and surrounding tissue is then irradiated with a neutron beam resulting in thermal neutron/ 10 B reactions ( 10 B(n,α) 7 Li) resulting in the production of localized high LET radiation from alpha and 7 Li particles. These products of the neutron capture reaction are very damaging to cells, but of short range so that the majority of the ionizing energy released is microscopically confined to the vicinity of the boron-containing compound. In principal it should be possible with BNCT to selectively destroy small nests or even single cancer cells located within normal tissue. It follows that the major improvements in this form of radiation therapy are going to come largely from the development of boron compounds with greater tumor selectivity, although there will certainly be advances made in neutron beam quality as well as the possible development of alternative sources of neutron beams, particularly accelerator-based epithermal neutron beams

  20. Boron neutron capture therapy of malignant brain tumors at the Brookhaven Medical Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Joel, D.D.; Coderre, J.A.; Chanana, A.D. [Brookhaven National Lab., Upton, NY (United States). Medical Dept.

    1996-12-31

    Boron neutron capture therapy (BNCT) is a bimodal form of radiation therapy for cancer. The first component of this treatment is the preferential localization of the stable isotope {sup 10}B in tumor cells by targeting with boronated compounds. The tumor and surrounding tissue is then irradiated with a neutron beam resulting in thermal neutron/{sup 10}B reactions ({sup 10}B(n,{alpha}){sup 7}Li) resulting in the production of localized high LET radiation from alpha and {sup 7}Li particles. These products of the neutron capture reaction are very damaging to cells, but of short range so that the majority of the ionizing energy released is microscopically confined to the vicinity of the boron-containing compound. In principal it should be possible with BNCT to selectively destroy small nests or even single cancer cells located within normal tissue. It follows that the major improvements in this form of radiation therapy are going to come largely from the development of boron compounds with greater tumor selectivity, although there will certainly be advances made in neutron beam quality as well as the possible development of alternative sources of neutron beams, particularly accelerator-based epithermal neutron beams.

  1. Discharge cleaning on TFTR after boronization

    International Nuclear Information System (INIS)

    Mueller, D.; Dylla, H.F.; LaMarche, P.H.; Bell, M.G.; Blanchard, W.; Bush, C.E.; Gentile, C.; Hawryluk, R.J.; HIll, K.W.; Janos, A.C.; Jobes, F.C; Owens, D.K.; Pearson, G.; Schivell, J.; Ulrickson, M.A.; Vannoy, C.; Wong, K.L.

    1991-05-01

    At the beginning of the 1990 TFTR experimental run, after replacement of POCO-AXF-5Q graphite tiles on the midplane of the bumper limiter by carbon fiber composite (CFC) tiles and prior to any Pulse Discharge Cleaning (PDC), boronization was performed. Boronization is the deposition of a layer of boron and carbon on the vacuum vessel inner surface by a glow discharge in a diborane, methane and helium mixture. The amount of discharge cleaning required after boronization was substantially reduced compared to that which was needed after previous openings when boronization was not done. Previously, after a major shutdown, about 10 5 low current (∼20 kA) Taylor Discharge Cleaning (TDC) pulses were required before high current (∼400 kA) aggressive Pulse Discharge Cleaning (PDC) pulses could be performed successfully. Aggressive PDC is used to heat the limiters from the vessel bakeout temperature of 150 degrees C to 250 degrees C for a period of several hours. Heating the limiters is important to increase the rate at which water is removed from the carbon limiter tiles. After boronization, the number of required TDC pulses was reduced to <5000. The number of aggressive PDC pulses required was approximately unchanged. 14 refs., 1 tab

  2. Large animal normal tissue tolerance with boron neutron capture

    International Nuclear Information System (INIS)

    Gavin, P.R.; Swartz, C.D.; Kraft, S.L.; Briebenow, M.L.; DeHaan, C.E.

    1994-01-01

    Normal tissue tolerance of boron neutron capture irradiation using borocaptate sodium (NA 2 B 12 H 11 SH) in an epithermal neutron beam was studied. Large retriever-type dogs were used and the irradiations were performed by single dose, 5 x 10 dorsal portal. Fourteen dogs were irradiated with the epithermal neutron beam alone and 35 dogs were irradiated following intravenous administration of borocaptate sodium. Total body irradiation effect could be seen from the decreased leukocytes and platelets following irradiation. Most values returned to normal within 40 days postirradiation. Severe dermal necrosis occurred in animals given 15 Gy epithermal neutrons alone and in animals irradiated to a total peak physical dose greater than 64 Gy in animals following borocaptate sodium infusion. Lethal brain necrosis was seen in animals receiving between 27 and 39 Gy. Lethal brain necrosis occurred at 22-36 weeks postirradiation. A total peak physical dose of approximately 27 Gy and blood-boron concentrations of 25-50 ppm resulted in abnormal magnetic resonance imaging results in 6 months postexamination. Seven of eight of these animals remained normal and the lesions were not detected at the 12-month postirradiation examination. The bimodal therapy presents a complex challenge in attempting to achieve dose response assays. The resultant total radiation dose is a composite of low and high LET components. The short track length of the boron fission fragments and the geometric effect of the vessels causes much of the intravascular dose to miss the presumed critical target of the endothelial cells. The results indicate a large dose-sparing effect from the boron capture reactions within the blood. 23 refs., 6 figs., 2 tabs

  3. Proceedings of workshop on 'boron chemistry and boron neutron capture therapy'

    International Nuclear Information System (INIS)

    Kitaoka, Yoshinori

    1992-09-01

    This volume contains the proceedings of the 4th Workshop on 'the Boron Chemistry and Boron Neutron Capture Therapy' held on February 24 in 1992. First, clinical experiences of BNCT in the Kyoto University Research Reactor in 1992 were briefly reported. Then, the killing effects of boron cluster-containing nucleic acid precursors on tumor cells were shown (Chap. 2). The various trials of the optical resolution of B-p-boronophenylalanine for neutron capture therapy were made (Chap. 3). The borate-dextran gel complexes were investigated by the nuclear magnetic resonance spectroscopy. The stability constants of borate complexes were listed, and are useful in the solution chemistry of boron compounds (Chap. 4). The interactions between boron compounds and biological materials were studied by the paper electrophoresis which had been developed by us (Chap. 5). Molecular design of boron-10 carriers and their organic synthesis were reported (Chap. 6). Carborane-containing aziridine boron carriers which were directed to the DNA alkylation were synthesized and their cancer cell killing efficacies were tested (Chap. 7). The solution chemistry of deuterium oxide which is a good neutron moderator was reported, relating to the BNCT (Chap. 8). (author)

  4. Strategies for oral delivery and mitochondrial targeting of CoQ10.

    Science.gov (United States)

    Zaki, Noha M

    2016-07-01

    Coenzyme Q10 (CoQ10), also known as ubiquinone or ubidecarenone, is a powerful, endogenously produced, intracellularly existing lipophilic antioxidant. It combats reactive oxygen species (ROS) known to be responsible for a variety of human pathological conditions. Its target site is the inner mitochondrial membrane (IMM) of each cell. In case of deficiency and/or aging, CoQ10 oral supplementation is warranted. However, CoQ10 has low oral bioavailability due to its lipophilic nature, large molecular weight, regional differences in its gastrointestinal permeability and involvement of multitransporters. Intracellular delivery and mitochondrial target ability issues pose additional hurdles. To maximize CoQ10 delivery to its biopharmaceutical target, numerous approaches have been undertaken. The review summaries the current research on CoQ10 bioavailability and highlights the headways to obtain a satisfactory intracellular and targeted mitochondrial delivery. Unresolved questions and research gaps were identified to bring this promising natural product to the forefront of therapeutic agents for treatment of different pathologies.

  5. Chemoradiotherapy of cancer using boronated monoclonal antibodies. Progress report, December 1, 1982-November 30, 1983

    International Nuclear Information System (INIS)

    Soloway, A.H.

    1984-01-01

    The feasibility was established of using antibodies for the delivery of 10 B. Problems faced included 1) preservation of antibody activity following boronation, 2) antigenic receptor site density of the target cells, and 3) delivery of a critical number of 10 B atoms per cell. The linkage of a heavily boronated polymeric species to antibody by means of a single functional group allow for the delivery of a large number 10 B atoms per antibody molecule without a significant reduction in affinity. Both the polyclonally derived anti-thymocyte globulin (ATG) and the monoclonal anti-colorectal carcinoma antibody (17-1A) recognize antigens that are expressed with a density of approximately 10 6 epitopes per cell. The major concept that we advance is that just as effective cancer chemotherapy is based on the use of a combination of drugs, similarly a combination of compounds could be employed to deliver the requisite amount of 10 B to tumor target cells. This could include compounds such as Na 2 B 12 H 11 Sh together with boronated antibodies directed against tumor associated antigens. (DT)

  6. A colorimetric determination of boron in biological sample for boron neutron capture therapy (BNCT)

    International Nuclear Information System (INIS)

    Camillo, M.A.P.; Tomac Junior, U.

    1990-01-01

    The boron neutron capture therapy (BNCT) has shown better prognosis in the treatment of glyemas and gluoblastomas grade III and IV than other therapies. During the treatment the levels of Na 2 10 B 12 H 11 SH must be known in several compartiments of the organism and with this purpose the method of colorimetric determination of boron using curcumine was established. This method is simple, reprodutible and adequate sensitivity for this control. (author) [pt

  7. A colorimetric determination of boron in biological sample for boron neutron capture therapy

    International Nuclear Information System (INIS)

    Camilo, M.A.P.; Tomac Junior, U.

    1989-01-01

    The boron neutron capture therapy (BNCT) has shown better prognosis in the treatment of gliomas and glioblastomas grade III and IV than other therapies. During the treatment of levels of Na 2 10 B 12 H 11 S H must be known in several compartments of the organism and with this purpose the method of colorimetric determination of boron using curcumin was established. This method is simples, reproducible and has adequate sensitivity for this control. (author). 7 refs, 3 figs, 1 tab

  8. Boron ion beam generation using a self-sputtering planar magnetron.

    Science.gov (United States)

    Vizir, Aleksey; Nikolaev, Aleksey; Oks, Efim; Savkin, Konstantin; Shandrikov, Maxim; Yushkov, Georgy

    2014-02-01

    A boron ion source based on planar magnetron discharge with solid boron target has been developed. To obtain a sufficient conductivity of the boron target for high current discharge ignition, the target was heated to the temperature more than 350 °C. To reach this temperature, thermally isolated target was heated by low-current high-voltage magnetron DC discharge. Applying a high-current pulse (100 μs range) provides a self-sputtering mode of the discharge, which generates the boron plasma. Boron ion beam with current more than 150 mA was extracted from the plasma by applying an accelerating voltage of 20 kV. The boron ion fraction in the beam reached 95%, averaged over the pulse length, and the rest ions were working gas (Kr(+)). It was shown that "keeping alive" DC discharge completely eliminates a time delay of pulsed discharge current onset, and reduces the pulsed discharge minimal working pressure.

  9. Rapid mass-spectrometric determination of boron isotopic distribution in boron carbide.

    Science.gov (United States)

    Rein, J E; Abernathey, R M

    1972-07-01

    Boron isotopic ratios are measured in boron carbide by thermionic ionization mass spectrometry with no prior chemical separation. A powder blend of boron carbide and sodium hydroxide is prepared, a small portion is transferred to a tantalum filament, the filament is heated to produce sodium borate, and the filament is transferred to the mass spectrometer where the(11)B/(10)B ratio is measured, using the Na(2)BO(2)(+) ion. Variables investigated for their effect on preferential volatilization of (10)B include the sodium hydroxide-boron carbide ratio and the temperature and duration of filament heating. A series of boron carbide pellets containing natural boron, of the type proposed for the control rods of the Fast Flux Test Facility reactor, were analysed with an apparently unbiased result of 4.0560 for the (11)B/(10)B ratio (standard deviation 0.0087). The pellets contained over 3% metal impurities typically found in this material. Time of analysis is 45 min per sample, with one analyst.

  10. Boron Drug Delivery via Encapsulated Magnetic Nanocomposites: A New Approach for BNCT in Cancer Treatment

    Directory of Open Access Journals (Sweden)

    Yinghuai Zhu

    2010-01-01

    Full Text Available Ortho-carborane cages have been successfully attached to modified magnetic nanoparticles via catalytic azide-alkyne cycloadditions between 1-R-2-butyl-Ortho-C2B10H10(R=Me,3;Ph,4 and propargyl group-enriched magnetic nanoparticles. A loading amount of 9.83 mmol boron atom/g starch-matrixed magnetic nanoparticles has been reached. The resulting nanocomposites have been found to be highly tumor-targeted vehicles under the influence of an external magnetic field (1.14T, yielding a high boron concentration of 51.4 μg/g tumor and ratios of around 10 : 1 tumor to normal tissues.

  11. Pulverization of boron element and proportions of boron carbide in boron

    International Nuclear Information System (INIS)

    Lang, F.M.; Finck, C.

    1956-01-01

    It is possible to reduce boron element into fine powder by means of a mortar and pestle made of sintered boron carbide, the ratio of boron carbide introduced being less than one per cent. Boron element at our disposal is made of sharp edged, dark brown, little grains of average size greater than 5 μ. Grain sizes smaller than 1μ are required for applying thin layers of such boron. (author) [fr

  12. Commissioning of accelerator based boron neutron capture therapy system

    International Nuclear Information System (INIS)

    Nakamura, S.; Wakita, A.; Okamoto, H.; Igaki, H.; Itami, J.; Ito, M.; Abe, Y.; Imahori, Y.

    2017-01-01

    Boron neutron capture therapy (BNCT) is a treatment method using a nuclear reaction of 10 B(n, α) 7 Li. BNCT can be deposited the energy to a tumor since the 10 B which has a higher cross-section to a neutron is high is concentrated on the tumor. It is different from conventional radiation therapies that BNCT expects higher treatment effect to radiation resistant tumors since the generated alpha and lithium particles have higher radiological biological effectiveness. In general, BNCT has been performed in research nuclear reactor. Thus, BNCT is not widely applied in a clinical use. According to recent development of accelerator-based boron neutron capture therapy system, the system has an adequate flux of neutrons. Therefore, National Cancer Canter Hospital, Tokyo, Japan is planning to install accelerator based BNCT system. Protons with 2.5 MeV are irradiated to a lithium target system to generate neutrons. As a result, thermal load of the target is 50 kW since current of the protons is 20.0 mA. Additionally, when the accelerator-based BNCT system is installed in a hospital, the facility size is disadvantage in term of neutron measurements. Therefore, the commissioning of the BNCT system is being performed carefully. In this article, we report about the commissioning. (author)

  13. Pulsed laser deposited KY3F10: Ho3+ thin films: Influence of target to substrate

    CSIR Research Space (South Africa)

    Debelo, NG

    2017-04-01

    Full Text Available The influence of target to substrate distance (dts) on the structural, morphological and photoluminescence (PL) properties of commercially obtained KY3F10 : Ho3+ phosphor thin films prepared by pulsed laser deposition is investigated for dts values...

  14. Boron Removal in Seawater Reverse Osmosis System

    KAUST Repository

    Rahmawati, Karina

    2011-07-01

    Reverse osmosis successfully proves to remove more than 99% of solute in seawater, providing fresh water supply with satisfied quality. Due to some operational constraints, however, some trace contaminants removal, such as boron, cannot be achieved in one pass system. The stringent criterion for boron from World Health Organization (WHO) and Saudi Arabia local standard (0.5 mg/l) is hardly fulfilled by single pass sea water reverse osmosis (SWRO) plants. Some design processes have been proposed to deal with boron removal, but they are not economically efficient due to high energy and chemical consumption. The objective of this study was to study boron removal by different reverse osmosis membranes in two pH conditions, with and without antiscalant addition. Thus, it was expected to observe the possibility of operating single pass system and necessity to operate two pass system using low energy membrane. Five membrane samples were obtained from two different manufacturers. Three types of feed water pH were used, pH 8, pH 10, and pH 10 with antiscalant addition. Experiment was conducted in parallel to compare membrane performance from two manufacturers. Filtration was run with fully recycle mode for three days. Sample of permeate and feed were taken every 12 hours, and analyzed for their boron and TDS concentration. Membrane samples were also tested for their surface charge. The results showed that boron rejection increases as the feed pH increases. This was caused by dissociation of boric acid to negatively charged borate ion and more negatively charged membrane surface at elevated pH which enhance boron rejection. This study found that single pass reverse osmosis system, with and without elevating the pH, may not be possible to be applied because of two reasons. First, permeate quality in term of boron, does not fulfill WHO and local Saudi Arabia regulations. Second, severe scaling occurs due to operation in alkaline condition, since Ca and Mg concentration are

  15. miRNA-135a promotes breast cancer cell migration and invasion by targeting HOXA10

    International Nuclear Information System (INIS)

    Chen, Yating; Zhang, Hongwei; Ma, Duan; Zhang, Jin; Wang, Huijun; Zhao, Jiayi; Xu, Cheng; Du, Yingying; Luo, Xin; Zheng, Fengyun; Liu, Rui

    2012-01-01

    miRNAs are a group of small RNA molecules regulating target genes by inducing mRNA degradation or translational repression. Aberrant expression of miRNAs correlates with various cancers. Although miR-135a has been implicated in several other cancers, its role in breast cancer is unknown. HOXA10 however, is associated with multiple cancer types and was recently shown to induce p53 expression in breast cancer cells and reduce their invasive ability. Because HOXA10 is a confirmed miR-135a target in more than one tissue, we examined miR-135a levels in relation to breast cancer phenotypes to determine if miR-135a plays role in this cancer type. Expression levels of miR-135a in tissues and cells were determined by poly (A)-RT PCR. The effect of miR-135a on proliferation was evaluated by CCK8 assay, cell migration and invasion were evaluated by transwell migration and invasion assays, and target protein expression was determined by western blotting. GFP and luciferase reporter plasmids were constructed to confirm the action of miR-135a on downstream target genes including HOXA10. Results are reported as means ± S.D. and differences were tested for significance using 2-sided Student's t-test. Here we report that miR-135a was highly expressed in metastatic breast tumors. We found that the expression of miR-135a was required for the migration and invasion of breast cancer cells, but not their proliferation. HOXA10, which encodes a transcription factor required for embryonic development and is a metastasis suppressor in breast cancer, was shown to be a direct target of miR-135a in breast cancer cells. Our analysis showed that miR-135a suppressed the expression of HOXA10 both at the mRNA and protein level, and its ability to promote cellular migration and invasion was partially reversed by overexpression of HOXA10. In summary, our results indicate that miR-135a is an onco-miRNA that can promote breast cancer cell migration and invasion. HOXA10 is a target gene for mi

  16. Study of the boron levels in serum after implantation of different ratios nano-hexagonal boron nitride-hydroxy apatite in rat femurs.

    Science.gov (United States)

    Atila, Alptug; Halici, Zekai; Cadirci, Elif; Karakus, Emre; Palabiyik, Saziye Sezin; Ay, Nuran; Bakan, Feray; Yilmaz, Sahin

    2016-01-01

    Boron and its derivatives are effective in bone recovery and osteointegration. However, increasing the boron levels in body liquids may cause toxicity. The aim of our study is to investigate serum boron levels using ICP-MS after implantation of different ratios of nano-hBN-HA composites in rat femurs. All rats were (n=126) divided into five experimental groups (n=24) and one healthy group (6 rats); healthy (Group1), femoral defect + %100 HA (Group2), femoral defect + %2.5 hBN + %97.5 HA (Group3), femoral defect + %5 hBN + %95 HA (Group4), femoral defect + %10 hBN + %90 HA (Group5), femoral defect + %100 hBN (Group6). The femoral defect was created in the distal femur (3mm drill-bit). Each implant group was divided into four different groups (n=24) also 6 rats sacrificed for each groups in one week intervals during four weeks. In our results; at 1, 2, 3, and 4 weeks after implantation near bone tissue, serum levels of boron were evaluated using ICP-MS. We demonstrated that neither short-term nor long-term implantation of hBN-HA composite resulted in statistically increased serum boron levels in experimental groups compared to healthy group. In conclusion, this study investigated the implant material produced form hBN-HA for the first time. Our data suggest that hBN is a new promising target for biomaterial and implant bioengineers. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Complexion of Boric Acid with 2-Deoxy-D-glucose (DG) as a novel boron carrier for BNCT

    OpenAIRE

    Akan, Zafer; Demiroglu, Hasan; Avcibasi, Ugur; Oto, Gokhan; Ozdemir, Hulya; Deniz, Sabahattin; Basak, Ali Sadi

    2014-01-01

    Objective: Boron neutron capture therapy (BNCT) is an intensive research area for cancer researchers. Especially the side effects and inabilities of conventional therapies in some cases, directs researchers to find out a new cancer therapy methods such as BNCT. One of three important problem of BNCT is targeting of boron to tumor tissue. Borono Phenyl Alanine (BPA) and Borono Sodium Borocaptate (BSH) are already using in clinical studies as boron carriers. New boron carriers are searching fo...

  18. Development of beryllium-based neutron target system with three-layer structure for accelerator-based neutron source for boron neutron capture therapy.

    Science.gov (United States)

    Kumada, Hiroaki; Kurihara, Toshikazu; Yoshioka, Masakazu; Kobayashi, Hitoshi; Matsumoto, Hiroshi; Sugano, Tomei; Sakurai, Hideyuki; Sakae, Takeji; Matsumura, Akira

    2015-12-01

    The iBNCT project team with University of Tsukuba is developing an accelerator-based neutron source. Regarding neutron target material, our project has applied beryllium. To deal with large heat load and blistering of the target system, we developed a three-layer structure for the target system that includes a blistering mitigation material between the beryllium used as the neutron generator and the copper heat sink. The three materials were bonded through diffusion bonding using a hot isostatic pressing method. Based on several verifications, our project chose palladium as the intermediate layer. A prototype of the neutron target system was produced. We will verify that sufficient neutrons for BNCT treatment are generated by the device in the near future. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Appraisal of SIMS applicability to boron studies in plants.

    Science.gov (United States)

    Dérue, Cedric; Gibouin, David; Verdus, Marie-Claire; Lefebvre, Fabrice; Demarty, Maurice; Ripoll, Camille; Thellier, Michel

    2002-07-15

    In the search for a new methodological approach applicable to the determination of the still poorly known primary role of boron in plant physiology, we have undertaken to appraise the potential of the SIMS method for the analytical imaging of the boron isotopes, (10)B and (11)B, at physiological concentrations in plants. With our own, CAMECA IMS4F SIMS ion analyser, and using O(2)(+) as primary ions for the detection of B(+) (plus (12)C(+) and (40)Ca(+)) secondary ions, we have been able to map quantitatively the two boron isotopes in control and boron-enriched plants, to evaluate boron concentrations at the level of individual cells and to determine boron isotopic ratios. This provides the opportunity to carry out the simultaneous labeling and imaging of boron, using enrichment with the stable isotopes, (10)B and (11)B. The method has also the potential for the simultaneous, quantitative detection of the boron isotopes and of the borate-binding sites in plant cells. Copyright 2002 Wiley-Liss, Inc.

  20. Boron Isotopes Enrichment via Continuous Annular Chromatography

    OpenAIRE

    Sağlam, Gonca

    2016-01-01

    ABSTRACT Boron has two stable isotopes namely 10B and 11B isotopes. The large cross section of 10B isotope for thermal neutrons is used for reactor control in nuclear fission reactors. The thermal neutrons absorption cross sections of pure 10B and 11B are 3837 and 0.005 barns respectively. In the literature, amongst others, batch elution chromatography techniques are reported for 10B isotope enrichment. This work focuses on continuous chromatographic 10B isotope separation system via continuo...

  1. Boron delivery with liposomes for boron neutron capture therapy (BNCT): biodistribution studies in an experimental model of oral cancer demonstrating therapeutic potential

    International Nuclear Information System (INIS)

    Nigg, David W.

    2012-01-01

    Boron neutron capture therapy (BNCT) combines selective accumulation of 10B carriers in tumor tissue with subsequent neutron irradiation. We previously demonstrated the therapeutic efficacy of BNCT in the hamster cheek pouch oral cancer model. Optimization of BNCT depends largely on improving boron targeting to tumor cells. Seeking to maximize the potential of BNCT for the treatment for head and neck cancer, the aim of the present study was to perform boron biodistribution studies in the oral cancer model employing two different liposome formulations that were previously tested for a different pathology, i.e., in experimental mammary carcinoma in BALB/c mice: (1) MAC: liposomes incorporating K(nido-7-CH3(CH2)15-7,8-C2B9H11) in the bilayer membrane and encapsulating a hypertonic buffer, administered intravenously at 6 mg B per kg body weight, and (2) MAC-TAC: liposomes incorporating K(nido-7-CH3(CH2)15-7,8-C2B9H11) in the bilayer membrane and encapsulating a concentrated aqueous solution of the hydrophilic species Na3 (ae-B20H17NH3), administered intravenously at 18 mg B per kg body weight. Samples of tumor, precancerous and normal pouch tissue, spleen, liver, kidney, and blood were taken at different times post-administration and processed to measure boron content by inductively coupled plasma mass spectrometry. No ostensible clinical toxic effects were observed with the selected formulations. Both MAC and MAC-TAC delivered boron selectively to tumor tissue. Absolute tumor values for MAC-TAC peaked to 66.6 ± 16.1 ppm at 48 h and to 43.9 ± 17.6 ppm at 54 h with very favorable ratios of tumor boron relative to precancerous and normal tissue, making these protocols particularly worthy of radiobiological assessment. Boron concentration values obtained would result in therapeutic BNCT doses in tumor without exceeding radiotolerance in precancerous/normal tissue at the thermal neutron facility at RA-3.

  2. Boron delivery with liposomes for boron neutron capture therapy (BNCT): biodistribution studies in an experimental model of oral cancer demonstrating therapeutic potential

    Energy Technology Data Exchange (ETDEWEB)

    David W. Nigg

    2012-05-01

    Boron neutron capture therapy (BNCT) combines selective accumulation of 10B carriers in tumor tissue with subsequent neutron irradiation. We previously demonstrated the therapeutic efficacy of BNCT in the hamster cheek pouch oral cancer model. Optimization of BNCT depends largely on improving boron targeting to tumor cells. Seeking to maximize the potential of BNCT for the treatment for head and neck cancer, the aim of the present study was to perform boron biodistribution studies in the oral cancer model employing two different liposome formulations that were previously tested for a different pathology, i.e., in experimental mammary carcinoma in BALB/c mice: (1) MAC: liposomes incorporating K[nido-7-CH3(CH2)15-7,8-C2B9H11] in the bilayer membrane and encapsulating a hypertonic buffer, administered intravenously at 6 mg B per kg body weight, and (2) MAC-TAC: liposomes incorporating K[nido-7-CH3(CH2)15-7,8-C2B9H11] in the bilayer membrane and encapsulating a concentrated aqueous solution of the hydrophilic species Na3 [ae-B20H17NH3], administered intravenously at 18 mg B per kg body weight. Samples of tumor, precancerous and normal pouch tissue, spleen, liver, kidney, and blood were taken at different times post-administration and processed to measure boron content by inductively coupled plasma mass spectrometry. No ostensible clinical toxic effects were observed with the selected formulations. Both MAC and MAC-TAC delivered boron selectively to tumor tissue. Absolute tumor values for MAC-TAC peaked to 66.6 {+-} 16.1 ppm at 48 h and to 43.9 {+-} 17.6 ppm at 54 h with very favorable ratios of tumor boron relative to precancerous and normal tissue, making these protocols particularly worthy of radiobiological assessment. Boron concentration values obtained would result in therapeutic BNCT doses in tumor without exceeding radiotolerance in precancerous/normal tissue at the thermal neutron facility at RA-3.

  3. Update on human health effects of boron.

    Science.gov (United States)

    Nielsen, Forrest H

    2014-10-01

    In vitro, animal, and human experiments have shown that boron is a bioactive element in nutritional amounts that beneficially affects bone growth and central nervous system function, alleviates arthritic symptoms, facilitates hormone action and is associated with a reduced risk for some types of cancer. The diverse effects of boron suggest that it influences the formation and/or activity of substances that are involved in numerous biochemical processes. Several findings suggest that this influence is through the formation of boroesters in biomolecules containing cis-hydroxyl groups. These biomolecules include those that contain ribose (e.g., S-adenosylmethionine, diadenosine phosphates, and nicotinamide adenine dinucleotide). In addition, boron may form boroester complexes with phosphoinositides, glycoproteins, and glycolipids that affect cell membrane integrity and function. Both animal and human data indicate that an intake of less than 1.0mg/day inhibits the health benefits of boron. Dietary surveys indicate such an intake is not rare. Thus, increasing boron intake by consuming a diet rich in fruits, vegetables, nuts and pulses should be recognized as a reasonable dietary recommendation to enhance health and well-being. Published by Elsevier GmbH.

  4. Boron removal by electrocoagulation and recovery.

    Science.gov (United States)

    Isa, Mohamed Hasnain; Ezechi, Ezerie Henry; Ahmed, Zubair; Magram, Saleh Faraj; Kutty, Shamsul Rahman Mohamed

    2014-03-15

    This work investigated the removal of boron from wastewater and its recovery by electrocoagulation and hydrothermal mineralization methods respectively. The experimental design was developed using Box-Behnken Model. An initial study was performed based on four preselected variables (pH, current density, concentration and time) using synthetic wastewater. Response surface methodology (RSM) was used to evaluate the effect of process variables and their interaction on boron removal. The optimum conditions were obtained as pH 6.3, current density 17.4 mA/cm(2), and time 89 min. At these applied optimum conditions, 99.7% boron removal from an initial concentration of 10.4 mg/L was achieved. The process was effectively optimized by RSM with a desirability value of 1.0. The results showed that boron removal efficiency enhanced with increase in current density and treatment time. Removal efficiency also increased when pH was increased from 4 to 7 and subsequently decreased at pH 10. Adsorption kinetics study revealed that the reaction followed pseudo second order kinetic model; evidenced by high correlation and goodness of fit. Thermodynamics study showed that mechanism of boron adsorption was chemisorption and the reaction was endothermic in nature. Furthermore, the adsorption process was spontaneous as indicated by negative values of the adsorption free energy. Treatment of real produced water using electrocoagulation resulted in 98% boron removal. The hydrothermal mineralization study showed that borate minerals (Inyoite, Takadaite and Nifontovite) can be recovered as recyclable precipitate from electrocoagulation flocs of produced water. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Accelerator-driven boron neutron capture therapy

    Science.gov (United States)

    Edgecock, Rob

    2014-05-01

    Boron Neutron Capture Therapy is a binary treatment for certain types of cancer. It works by loading the cancerous cells with a boron-10 carrying compound. This isotope has a large cross-section for thermal neutrons, the reaction producing a lithium nucleus and alpha particle that kill the cell in which they are produced. Recent studies of the boron carrier compound indicate that the uptake process works best in particularly aggressive cancers. Most studied is glioblastoma multiforme and a trial using a combination of BNCT and X-ray radiotherapy has shown an increase of nearly a factor of two in mean survival over the state of the art. However, the main technical problem with BNCT remains producing a sufficient flux of neutrons for a reasonable treatment duration in a hospital environment. This paper discusses this issue.

  6. The ternary system nickel-boron-silicon

    International Nuclear Information System (INIS)

    Lugscheider, E.; Reimann, H.; Knotek, O.

    1975-01-01

    The ternary system Nickel-Boron-Silicon was established at 850 0 C by means of X-ray diffraction, metallographic and micro-hardness examinations. The well known binary nickel borides and silicides resp. were confirmed. In the boron-silicon system two binary phases, SiBsub(4-x) with x approximately 0.7 and SiB 6 were found the latter in equilibrium with the β-rhombohedral boron. Confirming the two ternary silicon borides a greater homogeneity range was found for Ni 6 Si 2 B, the phase Nisub(4,6)Si 2 B published by Uraz and Rundqvist can better be described by the formula Nisub(4.29)Si 2 Bsub(1.43). In relation to further investigations we measured melting temperatures in ternary Ni-10 B-Si alloys by differential thermoanalysis. (author)

  7. Structure of Boron Carbide: Where's the Carbon?

    Science.gov (United States)

    Marx, David; Seidler, Gerald; Fister, Timothy; Nagle, Kenneth; Segre, Carlo

    2008-03-01

    Although the structure of the boron carbide series, B12-xCx with 0.06 x x-ray scattering (LERIX) spectrometer on the PNC-CAT beamline at the Advanced Photon Source at Argonne National Lab has enabled differentiation of the boron and carbon absorption edge data for the various crystallographic sites. The structure (R-3m) consists of twelve-atom icosahedra and three-atom chains. Boron carbide may have a maximum of three carbon atoms, which may be located on the two end of chain sites and in one of two inequivalent sites on the icosahedra. At least one carbon atom must be present in the structure for it to be stable. In this presentation, structural results from non-resonant x-ray scattering for seven samples, ranging from B4C to B10.1C will be presented.

  8. Achieving Boro Rice Production Targets in FY2009-10: Challenges and Actions Required

    OpenAIRE

    Uttam Deb; Nafisa Khaled; Subir Kanti Bairagi; Muhammad Al Amin; Mazbahul Golam Ahamad; Kaniz Tasnima

    2010-01-01

    The paper attempts to analyse the Boro production plan for FY2009-10, considering its special importance for Bangladesh in ensuring food security situation and keeping inflation in check. It reviews the policy measures and programmes taken so far in this regard. It also reports the implementation status of various projects for delivering inputs, namely seed, fertiliser, irrigation, credit and subsidy. Finally, the paper puts forward some suggestions for achieving the target set for production...

  9. Boronated liposome development and evaluation

    International Nuclear Information System (INIS)

    Hawthorne, M.F.

    1995-01-01

    The boronated liposome development and evaluation effort consists of two separate tasks. The first is the development of new boron compounds and the synthesis of known boron species with BNCT potential. These compounds are then encapsulated within liposomes for the second task, biodistribution testing in tumor-bearing mice, which examines the potential for the liposomes and their contents to concentrate boron in cancerous tissues

  10. Boronic acids facilitate rapid oxime condensations at neutral pH.

    Science.gov (United States)

    Schmidt, Pascal; Stress, Cedric; Gillingham, Dennis

    2015-06-01

    We report here the discovery and development of boron-assisted oxime formation as a powerful connective reaction for chemical biology. Oximes proximal to boronic acids form in neutral aqueous buffer with rate constants of more than 10 4 M -1 s -1 , the largest to date for any oxime condensation. Boron's dynamic coordination chemistry confers an adaptability that seems to aid a number of elementary steps in the oxime condensation. In addition to applications in bioconjugation, the emerging importance of boronic acids in chemical biology as carbohydrate receptors or peroxide probes, and the growing list of drugs and drug candidates containing boronic acids suggest many potential applications.

  11. The search for molecular effects in range corrections: boron determination by proton bombardment

    International Nuclear Information System (INIS)

    Olivier, C.; Peisach, M.

    1985-01-01

    Three different nuclear reactions viz. 10 B(p,αγ) 7 Be, 10 B(p,p,'γ) 10 B, and 11 B(p,p'γ) 11 B were used to analyse 21 pure boron compounds and mixtures of known composition by prompt gamma-ray spectrometry under proton bombardment. Elemental stopping powers were calculated from tables and used to compute the stopping power of the target matrices by Bragg's Law. Apparent discrepancies in the measured yield could point to deviations from Bragg's Law and hence to molecular effects. The maximum value for any molecular effect was found to be < 8,3%

  12. Compaction of amorphous iron–boron powder

    DEFF Research Database (Denmark)

    Hendriksen, Peter Vang; Mørup, Steen; Koch, Christian

    1993-01-01

    report on attempts to compact amorphous iron–boron particles prepared by chemical reduction of Fe(II) ions in aqueous solution by NaBH4 (Ref. 2). The particles prepared in this way are pyrophoric, but can be passivated. The small particle size (10–100 nm), characteristic of this preparation technique...

  13. Continued biological investigations of boron-rich oligomeric phosphate diesters (OPDs). Tumor-selective boron agents for BNCT

    International Nuclear Information System (INIS)

    Lee, Mark W.; Shelly, Kenneth; Kane, Robert R.; Hawthorne, M. Frederick

    2006-01-01

    Clinical success of Boron Neutron Capture Therapy will rely on the selective intracellular delivery of high concentrations of boron-10 to tumor tissue. In order for a boron agent to facilitate clinical success, the simultaneous needs of obtaining a high tumor dose, high tumor selectivity, and low systemic toxicity must be realized. Boron-rich oligomeric phosphate diesters (OPDs) are a class of highly water-soluble compounds containing up to 40% boron by weight. Previous work in our groups demonstrated that once placed in the cytoplasm of tumor cells, OPDs quickly accumulate within the cell nucleus. The objective of the current study was to determine the biodistribution of seven different free OPDs in BALB/c mice bearing EMT6 tumors. Fructose solutions containing between 1.4 and 6.4 micrograms of boron per gram of tissue were interveinously injected in mice seven to ten days after tumor implantation. At intervals during the study, animals were euthanized and samples of tumor, blood, liver, kidney, brain and skin were collected and analyzed for boron content using ICP-AES. Tumor boron concentrations of between 5 and 29 ppm were achieved and maintained over the 72-hour time course of each experiment. Several OPDs demonstrated high tumor selectivity with one oligomer exhibiting a tumor to blood ratio of 35:1. The apparent toxicity of each oligomer was assessed through animal behavior during the experiment and necropsy of each animal upon sacrifice. (author)

  14. Identification of direct regulatory targets of the transcription factor Sox10 based on function and conservation

    Directory of Open Access Journals (Sweden)

    Lee Sanghyuk

    2008-09-01

    Full Text Available Abstract Background Sox10, a member of the Sry-related HMG-Box gene family, is a critical transcription factor for several important cell lineages, most notably the neural crest stem cells and the derivative peripheral glial cells and melanocytes. Thus far, only a handful of direct target genes are known for this transcription factor limiting our understanding of the biological network it governs. Results We describe identification of multiple direct regulatory target genes of Sox10 through a procedure based on function and conservation. By combining RNA interference technique and DNA microarray technology, we have identified a set of genes that show significant down-regulation upon introduction of Sox10 specific siRNA into Schwannoma cells. Subsequent comparative genomics analyses led to potential binding sites for Sox10 protein conserved across several mammalian species within the genomic region proximal to these genes. Multiple sites belonging to 4 different genes (proteolipid protein, Sox10, extracellular superoxide dismutase, and pleiotrophin were shown to directly interact with Sox10 by chromatin immunoprecipitation assay. We further confirmed the direct regulation through the identified cis-element for one of the genes, extracellular superoxide dismutase, using electrophoretic mobility shift assay and reporter assay. Conclusion In sum, the process of combining differential expression profiling and comparative genomics successfully led to further defining the role of Sox10, a critical transcription factor for the development of peripheral glia. Our strategy utilizing relatively accessible techniques and tools should be applicable to studying the function of other transcription factors.

  15. In Vivo Boron Uptake Determination for Boron Neutron Capture Synovectomy

    Energy Technology Data Exchange (ETDEWEB)

    Binello, Emanuela; Shortkroff, Sonya; Yanch, Jacquelyn C.

    1999-06-06

    Boron neutron capture synovectomy (BNCS) has been proposed as a new application of the boron neutron capture reaction for the treatment of rheumatoid arthritis. In BNCS, a boron compound is injected into the joint space, where it is taken up by the synovium. The joint is then irradiated with neutrons of a desired energy range, inducing the boron neutron capture reaction in boron-loaded cells. Boron uptake by the synovium is an important parameter in the assessment of the potential of BNCS and in the determination of whether to proceed to animal irradiations for the testing of therapeutic efficacy. We present results from an investigation of boron uptake in vivo by the synovium.

  16. Preliminary evaluation of boron release and biological resistance of ...

    African Journals Online (AJOL)

    DOT) and a commercial water repellent compound. Leachates sampled from the leaching cycles for 10 days and extracts from treated wood specimens were analyzed for boron content. Treated wood specimens were exposed to wood degrading ...

  17. Mathematical modeling based evaluation and simulation of boron removal in bioelectrochemical systems

    Energy Technology Data Exchange (ETDEWEB)

    Ping, Qingyun [Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Abu-Reesh, Ibrahim M. [Department of Chemical Engineering, College of Engineering, Qatar University, P.O. Box 2713, Doha (Qatar); He, Zhen, E-mail: zhenhe@vt.edu [Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States)

    2016-11-01

    Boron removal is an arising issue in desalination plants due to boron's toxicity. As an emerging treatment concept, bioelectrochemical systems (BES) can achieve potentially cost-effective boron removal by taking advantage of cathodic-produced alkali. Prior studies have demonstrated successful removal of boron in microbial desalination cells (MDCs) and microbial fuel cells (MFCs), both of which are representative BES. Herein, mathematical models were developed to further evaluate boron removal by different BES and understand the key operating factors. The models delivered very good prediction of the boron concentration in the MDC integrated with Donnan Dialysis (DD) system with the lowest relative root-mean-square error (RMSE) of 0.00%; the predication of the MFC performance generated the highest RMSE of 18.55%. The model results of salt concentration, solution pH, and current generation were well fitted with experimental data for RMSE values mostly below 10%. The long term simulation of the MDC-DD system suggests that the accumulation of salt in the catholyte/stripping solution could have a positive impact on the removal of boron due to osmosis-driven convection. The current generation in the MDC may have little influence on the boron removal, while in the MFC the current-driven electromigration can contribute up to 40% of boron removal. Osmosis-induced convection transport of boron could be the major driving force for boron removal to a low level < 2 mg L{sup −} {sup 1}. The ratio between the anolyte and the catholyte flow rates should be kept > 22.2 in order to avoid boron accumulation in the anolyte effluent. - Highlights: • Mathematical models are developed to understand boron removal in BES. • Boron removal can be driven by electromigration induced by current generation. • Diffusion induced by a salt concentration gradient also contributes to boron removal. • Osmosis and current driven convection transport play diverse roles in different BES.

  18. Development of cancer therapy facility of HANARO and medical research in BNCT; development of the technique for boron concentration analysis

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hee Dong; Byun, Soo Hyun; Sun, Gwang Min; Kim, Suk Kwon; Kim, In Jung; Park, Chang Su [Seoul National University, Seoul (Korea)

    2002-03-01

    Objective and Necessity of the Project- Development of a boron concentration analysis facility used for BNCT. - Development of the technique for boron concentration analysis. Contents and Scopes of the Project - Construction of the boron concentration analysis facility based on PGAA. Estimation of the neutron beam characteristics. -Establishment of the technique for the boron concentration analysis. - Estimation of the reliability for the boron analysis. Results of the Project -Installation of the boron concentration analysis facility at Hanaro. - Neutron beam characteristics are the sample position (neutron flux : 7.9 x 10{sup 7} n/cm{sup 2}s, Cd-ratio : 266) Technique for the boron concentration analysis. - Boron detection sensitivity and limit (detection sensitivity : 2, 131 cps/mg-B, detection limit : 67 ng for 10,000 sec). 63 refs., 37 figs., 13 tabs. (Author)

  19. Development and validation of a method to determine the boron isotopic composition of crop plants.

    Science.gov (United States)

    Rosner, Martin; Pritzkow, Wolfgang; Vogl, Jochen; Voerkelius, Susanne

    2011-04-01

    We present a comprehensive chemical and mass spectrometric method to determine boron isotopic compositions of plant tissue. The method including dry ashing, a three-step ion chromatographic boron-matrix separation, and (11)B/(10)B isotope ratio determinations using the Cs(2)BO(2)(+) graphite technique has been validated using certified reference and quality control materials. The developed method is capable to determine δ(11)B values in plant tissue down to boron concentrations of 1 mg/kg with an expanded uncertainty of ≤1.7‰ (k = 2). The determined δ(11)B values reveal an enormous isotopic range of boron in plant tissues covering three-quarters of the natural terrestrial occurring variation in the boron isotopic composition. As the local environment and anthropogenic activity mainly control the boron intake of plants, the boron isotopic composition of plants can be used for food provenance studies.

  20. Potential of using boric acid as a boron drug for boron neutron capture therapy for osteosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, C.F.; Lin, S.Y. [Institute of Nuclear Engineering and Science, National Tsing Hua University, Taiwan (China); Peir, J.J. [Nuclear Science and Technology Development Center, National Tsing Hua University, Taiwan (China); Liao, J.W. [Graduate Institute of Veterinary Pathobiology, National Chung Hsing University, Taiwan (China); Lin, Y.C. [Department of Veterinary Medicine, National Chung Hsing University, Taiwan (China); Chou, F.I., E-mail: fichou@mx.nthu.edu.tw [Institute of Nuclear Engineering and Science, National Tsing Hua University, Taiwan (China)] [Nuclear Science and Technology Development Center, National Tsing Hua University, Taiwan (China)

    2011-12-15

    Osteosarcoma is a malignant tumor commonly found in human and animals. The ability of boric acid (BA) to accumulate in osteosarcoma due to the mechanism of the bone formation of cancer cells would make boron neutron capture therapy (BNCT) an alternative therapy for osteosarcoma. This study evaluated the feasibility of using BA as the boron drug for BNCT of bone cancer. The cytotoxicity of BA to L929 cells exceeded that of UMR-106 cells. With 25 {mu}g {sup 10}B/mL medium of BA treatment, the boron concentration in UMR-106 cells was higher than that in L929 cells. The biodistribution and pharmacokinetics of BA in Sprague-Dawley (SD) rats were studied by administrating 25 mg {sup 10}B/kg body weight to SD rats. Blood boron level decreased rapidly within one hour after BA injection. Boron concentration in the long bone was 4-6 time higher than that of blood. Results of this study suggest that BA may be a potential drug for BNCT for osteosarcoma.

  1. STELLAR BORON ABUNDANCES NEAR THE MAIN-SEQUENCE TURNOFF OF THE OPEN CLUSTER NGC 3293 AND IMPLICATIONS FOR THE EFFICIENCY OF ROTATIONALLY DRIVEN MIXING IN STELLAR ENVELOPES

    International Nuclear Information System (INIS)

    Proffitt, Charles R.; Lennon, Daniel J.; Langer, Norbert; Brott, Ines

    2016-01-01

    Spectra from the Hubble Space Telescope Cosmic Origins Spectrograph and the Space Telescope Imaging Spectrograph covering the B iii resonance line have been obtained for 10 early-B stars near the turnoff of the young Galactic open cluster NGC 3293. This is the first sample of boron abundance determinations in a single, clearly defined population of early-B stars that also covers a substantial range of projected rotational velocities. In most of these stars we detect partial depletion of boron at a level consistent with that expected for rotational mixing in single stars, but inconsistent with expectations for depletion from close binary evolution. However, our results do suggest that the efficiency of rotational mixing is at or slightly below the low end of the range predicted by the available theoretical calculations. The two most luminous targets observed have a very large boron depletion and may be the products of either binary interactions or post-main-sequence evolution.

  2. Process for microwave sintering boron carbide

    Science.gov (United States)

    Holcombe, C.E.; Morrow, M.S.

    1993-10-12

    A method of microwave sintering boron carbide comprises leaching boron carbide powder with an aqueous solution of nitric acid to form a leached boron carbide powder. The leached boron carbide powder is coated with a glassy carbon precursor to form a coated boron carbide powder. The coated boron carbide powder is consolidated in an enclosure of boron nitride particles coated with a layer of glassy carbon within a container for microwave heating to form an enclosed coated boron carbide powder. The enclosed coated boron carbide powder is sintered within the container for microwave heating with microwave energy.

  3. Bright prospects for boron

    NARCIS (Netherlands)

    Nanver, L.; Wassink, J.

    2012-01-01

    Professor Lis Nanver at Dimes has laid the foundation for a range of new photodetectors by creating a thin coating of boron on a silicon substrate. The sensors are used in ASML’s latest lithography machines and FEI’s most sensitive electron microscopes.

  4. Determination of boron in silicon related nuclear materials by spectrophotometry

    International Nuclear Information System (INIS)

    Ramanjaneyulu, P.S.; Sayi, Y.S.; Ramakumar, K.L.

    2007-01-01

    Boron is one of the important specifications in all-nuclear materials. The present paper describes in detail about the determination of boron in U-Al-Si and SILUMIN. The sample is treated with H 2 O 2 and 3 M HCl. Silicon will be left as precipitate. It was removed by centrifugation. Boron was selectively separated by solvent extraction with 10% 2-ethyl hexane 1,3-diol and was quantitatively determined by spectrophotometry using curcumin as complexing agent. Since standard reference materials are not available, standard addition method was employed to confirm the results. (author)

  5. Methods of producing continuous boron carbide fibers

    Science.gov (United States)

    Garnier, John E.; Griffith, George W.

    2015-12-01

    Methods of producing continuous boron carbide fibers. The method comprises reacting a continuous carbon fiber material and a boron oxide gas within a temperature range of from approximately 1400.degree. C. to approximately 2200.degree. C. Continuous boron carbide fibers, continuous fibers comprising boron carbide, and articles including at least a boron carbide coating are also disclosed.

  6. LBNE lattice & optics for proton extraction at MI-10 and transport to a target above grade

    Energy Technology Data Exchange (ETDEWEB)

    Johnstone, John A.; /Fermilab

    2011-09-01

    For the Long Baseline Neutrino Experiment (LBNE) at Fermilab 120 GeV/c protons will be transported from the Main Injector (MI) to an on-site production target. The lattice design and optics discussed here has the beam extracted vertically upwards from MI-10 and the keeps the majority of the line at an elevation above the glacial till/rock interface and terminates on a target at 10 ft above grade. The LBNE beamline discussed here is a modular optics design comprised of 3 distinct lattice configurations, including the specialized MI {yields} LBNE matching section and Final Focus. The remainder of the line is defined by six FODO cells, in which the length and phase advance are chosen specifically such that beam size does not exceed that of the MI while also making the most efficient use of space for achromatic insertions. Dispersion generated by variations in the beam trajectory are corrected locally and can not bleed out to corrupt the optics elsewhere in the line. Aperture studies indicate that the line should be able to transport the worst quality beam that the Main Injector might provide. New IDS dipole correctors located at every focusing center provide high-quality orbit control and further ensure that LBNE meets the stringent requirements for environmental protection.

  7. Composite boron nitride neutron detectors

    Science.gov (United States)

    Roth, M.; Mojaev, E.; Khakhan, O.; Fleider, A.; Dul`kin, E.; Schieber, M.

    2014-09-01

    Single phase polycrystalline hexagonal boron nitride (BN) or mixed with boron carbide (BxC) embedded in an insulating polymeric matrix acting as a binder and forming a composite material as well as pure submicron size polycrystalline BN has been tested as a thermal neutron converter in a multilayer thermal neutron detector design. Metal sheet electrodes were covered with 20-50 μm thick layers of composite materials and assembled in a multi-layer sandwich configuration. High voltage was applied to the metal electrodes to create an interspacing electric field. The spacing volume could be filled with air, nitrogen or argon. Thermal neutrons were captured in converter layers due to the presence of the 10B isotope. The resulting nuclear reaction produced α-particles and 7Li ions which ionized the gas in the spacing volume. Electron-ion pairs were collected by the field to create an electrical signal proportional to the intensity of the neutron source. The detection efficiency of the multilayer neutron detectors is found to increase with the number of active converter layers. Pixel structures of such neutron detectors necessary for imaging applications and incorporation of internal moderator materials for field measurements of fast neutron flux intensities are discussed as well.

  8. SU-D-304-07: Application of Proton Boron Fusion Reaction to Radiation Therapy

    International Nuclear Information System (INIS)

    Jung, J; Yoon, D; Shin, H; Kim, M; Suh, T

    2015-01-01

    Purpose: we present the introduction of a therapy method using the proton boron fusion reaction. The purpose of this study is to verify the theoretical validity of proton boron fusion therapy using Monte Carlo simulations. Methods: After boron is accumulated in the tumor region, the emitted from outside the body proton can react with the boron in the tumor region. An increase of the proton’s maximum dose level is caused by the boron and only the tumor cell is damaged more critically. In addition, a prompt gamma ray is emitted from the proton boron reaction point. Here we show that the effectiveness of the proton boron fusion therapy (PBFT) was verified using Monte Carlo simulations. Results: We found that a dramatic increase by more than half of the proton’s maximum dose level was induced by the boron in the tumor region. This increase occurred only when the proton’s maximum dose point was located within the boron uptake region (BUR). In addition, the 719 keV prompt gamma ray peak produced by the proton boron fusion reaction was positively detected. Conclusion: This therapy method features the advantages such as the application of Bragg-peak to the therapy, the accurate targeting of tumor, improved therapy effects, and the monitoring of the therapy region during treatment

  9. Synthesis and in-vivo detection of boronated compounds for use in BNCT. Final progress report, August 1, 1989--April 30, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Kabalka, G.W.

    1993-08-01

    Carboranes contain ten boron atoms in a three-dimensional space equivalent to a benzene ring; consequently, the carborane isomers can be utilized to prepare a variety of boron-rich agents for potential use in boron-neutron capture therapy. We developed synthetic methodology suitable for use with carboranes preparing amino acids and other physio-logically active compounds of potential use in BNCT. The methodology involves the conversion of simple carboranes into more complex, reactive organometallic reagents which can then be utilized to prepare agents which will target the nuclei of tumor cells. Specific examples include the projected syntheses of boron analogs of known intercolators such as Diazaquone (AZQ) which have been proven effectiveness in chemotherapy. We have also synthesized and carried out biodistribution studies of gadolinium labeled liposomes (GLL) which were developed in our laboratory. Gadolinium like boron-10, has an excellent neutron cross section and is considered to be of potential use in neutron capture therapy. GLL are constructed by adding gadolinium based amphiphiles.

  10. Effect of Boronization on Ohmic Plasmas in NSTX

    International Nuclear Information System (INIS)

    Skinner, C.H.; Kugel, H.; Maingi, R.; Wampler, W.R.; Blanchard, W.; Bell, M.; Bell, R.; LeBlanc, B.; Gates, D.; Kaye, S.; LaMarche, P.; Menard, J.; Mueller, D.; Na, H.K.; Nishino, N.; Paul, S.; Sabbagh, S.; Soukhanovskii, V.

    2001-01-01

    Boronization of the National Spherical Torus Experiment (NSTX) has enabled access to higher density, higher confinement plasmas. A glow discharge with 4 mTorr helium and 10% deuterated trimethyl boron deposited 1.7 g of boron on the plasma facing surfaces. Ion beam analysis of witness coupons showed a B+C areal density of 10 to the 18 (B+C) cm to the -2 corresponding to a film thickness of 100 nm. Subsequent ohmic discharges showed oxygen emission lines reduced by x15, carbon emission reduced by two and copper reduced to undetectable levels. After boronization, the plasma current flattop time increased by 70% enabling access to higher density, higher confinement plasmas

  11. High resolution imaging of boron carbide microstructures

    International Nuclear Information System (INIS)

    MacKinnon, I.D.R.; Aselage, T.; Van Deusen, S.B.

    1986-01-01

    Two samples of boron carbide have been examined using high resolution transmission electron microscopy (HRTEM). A hot-pressed B 13 C 2 sample shows a high density of variable width twins normal to (10*1). Subtle shifts or offsets of lattice fringes along the twin plane and normal to approx.(10*5) were also observed. A B 4 C powder showed little evidence of stacking disorder in crystalline regions

  12. Neutron sensitivity improvement in boron-lined proportional counters

    International Nuclear Information System (INIS)

    Dighe, P.M.; Prasad, K.R.; Kataria, S.K.

    2002-01-01

    Various techniques have been employed to improve the neutron sensitivity of boron-coated proportional counters developed indigenously. A boron-lined proportional counter (67 mm ID x 750 mm length) of 17 cps/nv thermal neutron sensitivity is developed by coating 92% enriched 10 B on the inner wall of the counter. This counter can be used for low thermal neutron flux (∼0.2 nv) at various applications such as neutron area monitoring, reactor start-up instrumentation, assay of fissile materials and detection of fuel failure. An improvement in sensitivity was also achieved by summing the output signals from four 10 B lined counters and two BF 3 proportional counters. The summation did not change the susceptibility of the device to gamma interference. In view of the scarcity of enriched 10 B isotope, indigenously available natural boron coated two prototype proportional counters are developed of 0.8 cps/nv and 1.1 cps/nv thermal neutron sensitivity. Efforts have been made to improve the sensitivity with boron coated 3-dimensional structures introduced into the sensitive volume. Tests in thermal neutron flux showed 50% improvement in the sensitivity due to the introduction of additional boron coated wires. Another counter with 51 boron-coated annular discs (23 mm OD X 10 mm ID X 1 mm thick) mounted perpendicular to the axis of the cathode showed 1.7 cps/nv neutron sensitivity, an improvement by a factor of 2.5. (author)

  13. Energetics of Boron Doping of Carbon Pores

    Science.gov (United States)

    Wexler, Carlos; St. John, Alexander; Connolly, Matthew

    2014-03-01

    Carbon-based materials show promise, given their light weight, large surface areas and low cost for storage of hydrogen and other gases, e.g., for energy applications. Alas, the interaction of H2 and carbon, 4-5kJ/mol, is insufficient for room-temperature operation. Boron doping of carbon materials could raise the binding energy of H2 to 12-15kJ/mol. The nature of the incorporation of boron into a carbon structure has not been studied so far. In this talk we will address the energetics of boron incorporation into a carbon matrix via adsorption and decomposition of decaborane by first principles calculations. These demonstrate: (a) A strong adsorption of decaborane to carbon (70-80kJ/mol) resulting in easy incorporation of decaborane, sufficient for up to 10-20% B:C at low decaborane vapour pressures. (b) Identification that boron acts as an electron acceptor when incorporated substitutionally into a graphene-like material, as expected due to its valence. (c) The electrostatic field near the molecule is responsible for ca. 2/3 of the enhancement of the H2-adsorbent interaction in aromatic compounds such as pyrene, coronene and ovalene. Supported by DOE DE-FG36-08GO18142, ACS-PRF 52696-ND5, and NSF 1069091.

  14. NEUTRON IRRADIATION EFFECTS ON SPARK PLASMA SINTERED BORON CARBIDE

    OpenAIRE

    Buyuk, Bulent; Cengiz, Meral; Tugrul, A. Beril

    2015-01-01

    In this study, spark plasma sintered boron carbide (B4C) was examined against neutrons. The specimens were irradiated by reactor neutrons (include both thermal and fast neutrons) up to fluence of 1.37x1021n m-2. Thermal and fast neutrons cause swelling by different interactions with boron (10B) atoms in the related materials. X-Ray diffraction (XRD) patterns and scanning electron microscopy (SEM) images were investigated for initial and irradiated samples. In addition, lattice parameters and ...

  15. Structures, stability, mechanical and electronic properties of α-boron and α*-boron

    OpenAIRE

    Chaoyu He; J. X. Zhong

    2013-01-01

    The structures, stability, mechanical and electronic properties of α-boron and a promising metastable boron phase (α*-boron) have been studied by first-principles calculations. α-boron and α*-boron consist of equivalent icosahedra B12 clusters in different connecting configurations of “3S-6D-3S” and “2S-6D-4S”, respectively. The total energy calculations show that α*-boron is less stable than α-boron but more favorable than the well-known β-boron and γ-boron at zero pressure. Both α-boron and...

  16. Comparison of boron and neon damage effects in boron ion-implanted resistors

    International Nuclear Information System (INIS)

    MacIver, B.A.

    1975-01-01

    Boron and neon damage implants were used in fabricating integrated-circuit resistors in silicon. Resistor properties were studied as functions of damaging ion species and dose. Sheet resistances in the 10 000 Ω/square range were obtained with low temperature and voltage sensitivities and d.c. isolation. (author)

  17. Boron Neutron Capture Therapy (BCNT) for the Treatment of Liver Metastases: Biodistribution Studies of Boron Compounds in an Experimental Model

    International Nuclear Information System (INIS)

    Garabalino, Marcela A.; Hughes, Andrea Monti; Molinari, Ana J.; Heber, Elisa M.; Pozzi, Emiliano C.C.; Itoiz, Maria E.; Trivillin, Veronica A.; Schwint, Amanda E.; Cardoso, Jorge E.; Colombo, Lucas L.; Nievas, Susana; Nigg, David W.; Aromando, Romina F.

    2011-01-01

    We previously demonstrated the therapeutic efficacy of different boron neutron capture therapy (BNCT) protocols in an experimental model of oral cancer. BNCT is based on the selective accumulation of 10B carriers in a tumor followed by neutron irradiation. Within the context of exploring the potential therapeutic efficacy of BNCT for the treatment of liver metastases, the aim of the present study was to perform boron biodistribution studies in an experimental model of liver metastases in rats. Different boron compounds and administration conditions were assayed to determine which administration protocols would potentially be therapeutically useful in in vivo BNCT studies at the RA-3 nuclear reactor. A total of 70 BDIX rats were inoculated in the liver with syngeneic colon cancer cells DHD/K12/TRb to induce the development of subcapsular tumor nodules. Fourteen days post-inoculation, the animals were used for biodistribution studies. We evaluated a total of 11 administration protocols for the boron compounds boronophenylalanine (BPA) and GB-10 (Na210B10H10), alone or combined at different dose levels and employing different administration routes. Tumor, normal tissue, and blood samples were processed for boron measurement by atomic emission spectroscopy. Six protocols proved potentially useful for BNCT studies in terms of absolute boron concentration in tumor and preferential uptake of boron by tumor tissue. Boron concentration values in tumor and normal tissues in the liver metastases model show it would be feasible to reach therapeutic BNCT doses in tumor without exceeding radiotolerance in normal tissue at the thermal neutron facility at RA-3.

  18. BORON-NITROGEN RELATIONSHIP IN WHEAT (Triticum aestivum L. GROWN WITH THE NUTRIENT SOLUTION

    Directory of Open Access Journals (Sweden)

    Mehmet ALPASLAN

    1996-03-01

    Full Text Available The effects of boron applied 0.01, 0.1, 1.0, and 10.0 µg B/ml levels as boric acid (H3 BO3, and nitrogen applied 25, 100, 200, and 400 µg N/ml as ammonium nitrate (NH4 NO3, respectively, on the amount of dry matter yield, and boron, nitrogen and nitrate contents of wheat (Triticum aestivum L. grown in perlite medium with Ruakura nutrient solution under greenhouse conditions were investigated. Dry matter yield and nitrate contents of wheat were decreased and boron content was increased with increasing boron application. Controversially, application of nitrogen increased dry matter yield, nitrogen and nitrate contents of wheat, while decreases in boron contents. Those effects of boron and nitrogen were found to be statistically significant (P

  19. Fivefold twinned boron carbide nanowires.

    Science.gov (United States)

    Fu, Xin; Jiang, Jun; Liu, Chao; Yuan, Jun

    2009-09-09

    Chemical composition and crystal structure of fivefold twinned boron carbide nanowires have been determined by electron energy-loss spectroscopy and electron diffraction. The fivefold cyclic twinning relationship is confirmed by systematic axial rotation electron diffraction. Detailed chemical analysis reveals a carbon-rich boron carbide phase. Such boron carbide nanowires are potentially interesting because of their intrinsic hardness and high temperature thermoelectric property. Together with other boron-rich compounds, they may form a set of multiply twinned nanowire systems where the misfit strain could be continuously tuned to influence their mechanical properties.

  20. Standard specification for boron-Based neutron absorbing material systems for use in nuclear spent fuel storage racks

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This specification defines criteria for boron-based neutron absorbing material systems used in racks in a pool environment for storage of nuclear light water reactor (LWR) spent-fuel assemblies or disassembled components to maintain sub-criticality in the storage rack system. 1.2 Boron-based neutron absorbing material systems normally consist of metallic boron or a chemical compound containing boron (for example, boron carbide, B4C) supported by a matrix of aluminum, steel, or other materials. 1.3 In a boron-based absorber, neutron absorption occurs primarily by the boron-10 isotope that is present in natural boron to the extent of 18.3 ± 0.2 % by weight (depending upon the geological origin of the boron). Boron, enriched in boron-10 could also be used. 1.4 The materials systems described herein shall be functional – that is always be capable to maintain a B10 areal density such that subcriticality Keff <0.95 or Keff <0.98 or Keff < 1.0 depending on the design specification for the service...

  1. Spectrographic determination of traces of boron in steels

    International Nuclear Information System (INIS)

    Alduan, F.A.; Roca, M.

    1976-01-01

    A spectrographic method has been developed to determine quantitatively boron in steels in the 0.5 to 250 ppm concentration range. The samples are dissolved in acids and transformed into oxides, avoiding boron losses by the addition of mannitol. For the fluoride evolution of boron in the dc arc the following compounds have been considered: CuF 2 , LiF, NaF, and SrF 2 . CuF 2 , at a concentration of 10%, provides the highest line-to-background intensity ratio. An arc current of 5 amperes eliminates the interference from iron spectrum on the most sensitive boron line - B 2497.7 A. Variations in chromium and nickel contents have no effect on the analytical results. (author)

  2. Boron isotopes as an artificial tracer.

    Science.gov (United States)

    Quast, Konrad W; Lansey, Kevin; Arnold, Robert; Bassett, Randy L; Rincon, Martha

    2006-01-01

    A field study was conducted using a combination of intrinsic and artificial tracers to estimate travel times and dilution during transport of infiltrate from a reclaimed water infiltration basin to nearby monitoring wells. A major study objective was to validate boric acid enriched in (10)B as an artificial tracer. Basin 10E at the Rio Hondo Spreading Grounds in Whittier, California, was the site of the test. The basin normally receives a mixture of treated municipal waste water, purchased State Project water, and local runoff from the San Gabriel River. Approximately 3.5 kg of (10)B-enriched boric acid was dispersed among 2.05 x 10(5) m(3) of basin water to initiate the experiment. The resultant median delta(11)B in the infiltration basin was -71 per thousand. Prior to tracer addition, the basin water had an intrinsic delta(11)B of +2 per thousand. Local monitoring wells that were used to assess travel times had delta(11)B values of +5 per thousand and +8 per thousand at the time of tracer addition. Analytic results supported an assumption that boron is conserved during ground water transport and that boron enriched in (10)B is a useful artificial tracer. Several intrinsic tracers were used to reinforce the boric acid tracer findings. These included stable isotopes of oxygen (delta(18)O) and hydrogen (deltaD), sulfate concentration, and the boron to chloride ratio. Xenon isotopes, (136)Xe and (124)Xe, also supported boron isotope results. Xenon isotopes were added to the recharge basin as dissolved gases by investigators from the Lawrence Livermore National Laboratory.

  3. Current status of boron neutron capture therapy of high grade gliomas and recurrent head and neck cancer

    Directory of Open Access Journals (Sweden)

    Barth Rolf F

    2012-08-01

    Full Text Available Abstract Boron neutron capture therapy (BNCT is a biochemically targeted radiotherapy based on the nuclear capture and fission reactions that occur when non-radioactive boron-10, which is a constituent of natural elemental boron, is irradiated with low energy thermal neutrons to yield high linear energy transfer alpha particles and recoiling lithium-7 nuclei. Clinical interest in BNCT has focused primarily on the treatment of high grade gliomas, recurrent cancers of the head and neck region and either primary or metastatic melanoma. Neutron sources for BNCT currently have been limited to specially modified nuclear reactors, which are or until the recent Japanese natural disaster, were available in Japan, United States, Finland and several other European countries, Argentina and Taiwan. Accelerators producing epithermal neutron beams also could be used for BNCT and these are being developed in several countries. It is anticipated that the first Japanese accelerator will be available for therapeutic use in 2013. The major hurdle for the design and synthesis of boron delivery agents has been the requirement for selective tumor targeting to achieve boron concentrations in the range of 20 μg/g. This would be sufficient to deliver therapeutic doses of radiation with minimal normal tissue toxicity. Two boron drugs have been used clinically, a dihydroxyboryl derivative of phenylalanine, referred to as boronophenylalanine or “BPA”, and sodium borocaptate or “BSH” (Na2B12H11SH. In this report we will provide an overview of other boron delivery agents that currently are under evaluation, neutron sources in use or under development for BNCT, clinical dosimetry, treatment planning, and finally a summary of previous and on-going clinical studies for high grade gliomas and recurrent tumors of the head and neck region. Promising results have been obtained with both groups of patients but these outcomes must be more rigorously evaluated in larger

  4. Multipurpose boron carbide-aluminum composite and its manufacture via the control of the microstructure

    International Nuclear Information System (INIS)

    Pyzik, A.J.; Aksay, I.A.

    1987-01-01

    A method of making a boron carbidealuminum composite is described comprising: heating a particulate boron carbide in the presence of free carbon to 1800 0 -2250 0 C wherein the resulting boron carbide exhibits a substantially reduced reaction rate with aluminum; and reacting the boron carbide with aluminum, wherein a boron carbide-aluminum composite is formed having a microstructure including principally boron carbide and aluminum metal homogeneously distributed throughout the composite. A method is described of making a boron carbide-aluminum composite of selected ceramic and metal content and microstructure, having high fracture toughness, fracture strength and Young's modulus, and low density. It consists of: dispersing a particulate boron carbide of less than 10 micrometers particle size in water at a pH selected to maximize electrostatic repelling forces on boron carbide particle surfaces; consolidating the boron carbide into a porous compact; sintering the compact, whereby an open porous structure is retained; infilterating the compact with aluminum; and heat treating the compact, whereby a voidless composite is formed having microstructure phases

  5. Determination of boron in nuclear materials at subppm levels by high pressure liquid chromatography (HPLC)

    International Nuclear Information System (INIS)

    Rao, Radhika M.; Aggarwal, S.K.

    2002-11-01

    Experiments were conducted for the determination of boron in U 3 O 8 powder, aluminium metal and milliQ water using dynamically modified Reversed Phase High Pressure Liquid Chromatography (RP-HPLC) and using two precolumn chromogenic agents viz. chromotropic acid and curcumin for complexing boron. The complex was separated from the excess of reagent and determined by HPLC. When present in subppm levels, chromotropic acid was used successfully only for determination boron in water samples. For determination of boron at subppm levels in uranium and aluminium samples, curcumin was used as the precolumn chromogenic agent. The boron curcumin complex (rosocyanin) was formed after extraction of boron with 2-ethyl-l, 3-hexane diol (EHD). The rosocyanin complex was then separated from excess curcumin by displacement chromatography. Linear calibration curves for boron amounts in the range of 0.02 μg to 0.5 μg were developed with correlation coefficients varying from 0.997 to 0.999 and were used for the determination of boron in aluminium and uranium samples. Precision of about 10% was achieved in samples containing less than 1 ppmw of boron. Detection limit of this method is 0.01 μg boron. (author)

  6. A novel 10B-enriched carboranyl-containing phthalocyanine as a radio- and photo-sensitising agent for boron neutron capture therapy and photodynamic therapy of tumours: in vitro and in vivo studies.

    Science.gov (United States)

    Friso, Elisabetta; Roncucci, Gabrio; Dei, Donata; Soncin, Marina; Fabris, Clara; Chiti, Giacomo; Colautti, Paolo; Esposito, Juan; De Nardo, Laura; Riccardo Rossi, Carlo; Nitti, Donato; Giuntini, Francesca; Borsetto, Lara; Jori, Giulio

    2006-01-01

    The synthesis of a Zn(ii)-phthalocyanine derivative bearing four 10B-enriched o-carboranyl units (10B-ZnB4Pc) and its natural isotopic abundance analogue (ZnB4Pc) in the peripheral positions of the tetraazaisoindole macrocycle is presented. The photophysical properties of ZnB4Pc, as tested against model biological systems, were found to be similar with those typical of other photodynamically active porphyrin-type photosensitisers, including a singlet oxygen quantum yield of 0.67. The carboranyl-carrying phthalocyanine was efficiently accumulated by B16F1 melanotic melanoma cells in vitro, appeared to be partitioned in at least some subcellular organelles and, upon red light irradiation, induced extensive cell mortality. Moreover, ZnB4Pc, once i.v.-injected to C57BL/6 mice bearing a subcutaneously transplanted pigmented melanoma, photosensitised an important tumour response, provided that the irradiation at 600-700 nm was performed 3 h after the phthalocyanine administration, when appreciable concentrations of ZnB4Pc were still present in the serum. Analogously, irradiation of the 10B-ZnB4Pc-loaded pigmented melanoma with thermal neutrons 24 h after injection led to a 4 day delay in tumour growth as compared with control untreated mice. These results open the possibility to use one chemical compound as both a photosensitising and a radiosensitising agent for the treatment of tumours by the combined application of photodynamic therapy and boron neutron capture therapy.

  7. From boron analogues of amino acids to boronated DNA: potential new pharmaceuticals and neutron capture agents

    International Nuclear Information System (INIS)

    Spielvogel, B.F.; Sood, Anup; Duke Univ., Durham, NC; Shaw, B.R.; Hall, I.H.

    1991-01-01

    Isoelectronic and isostructural boron analogues of the α-amino acids ranging from simple glycine analogues such as H 3 NBH 2 COOH and Me 2 NHBH 2 COOH to alanine analogues have been synthesised. A diverse variety of analogues, including precursors and derivatives (such as peptides) have potent pharmacological activity, including anticancer, antiinflammatory, analgesic, and hypolipidemic activity in animal model studies and in vitro cell cultures. Boronated nucleosides and (oligo)nucleotides, synthetic oligonucleotide analogues of ''antisense'' agents interact with a complementary nucleic acid sequence blocking the biological effect of the target sequence. Nucleosides boronated on the pyrimidine and purine bases have been prepared. It has been established that an entirely new class of nucleic acid derivatives is feasible in which one of the non-bridging oxygens in the internucleotide phosphodiester linkage can be replaced by an isoelectronic analogue, the borane group, (BH 3 ). The boronated oligonucleotides can be viewed as hybrids of the normal oxygen oligonucleotides and the methylphosphonate oligonucleotides. (author)

  8. MRO CRISM MAP-PROJECTED TARGETED REDUCED DATA RECORD V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This volume contains the CRISM Map-projected Targeted Reduced Data Record (MTRDR) archive, a collection of multiband image cubes derived from targeted (gimbaled)...

  9. Boronization study for application to large helical device

    Science.gov (United States)

    Noda, N.; Sagara, A.; Yamada, H.; Kubota, Y.; Inoue, N.; Akaishi, K.; Motojima, O.; Iwamoto, K.; Hashiba, M.; Fujita, I.; Hino, T.; Yamashina, T.; Okazaki, K.; Rice, J.; Yamage, M.; Toyoda, H.; Sugai, H.

    1995-04-01

    An experimental device named SUT ( SUrface modification Teststand) was constructed for a boronization study. An ultra high vacuum (UHV) condition, a changeable high temperature liner and in situ AES are three distinctive feature of the SUT device. Saturation density of oxygen atoms was as large as 1.2 × 10 17/cm 2 on a boronized surface, whereas 1.5 × 10 16/cm 2 on a bare stainless steel surface. It is found by AES analysis that the oxygen-contained layer was as thick as 50 nm from the top surface of the boron film. From such a large oxygen-saturation density, we expect that the oxygen-gettering ability of the boronized surface is likely to be maintained during one-day experiment of LHD. The oxygen-saturation behavior was quite similar between the boronized surfaces obtained with decaborane and diborane, which indicates that, as a working gas of the boronization, the decaborane works well compared with diborane, as far as oxygen gettering is concerned.

  10. Functionalization and cellular uptake of boron carbide nanoparticles. The first step toward T cell-guided boron neutron capture therapy.

    Science.gov (United States)

    Mortensen, M W; Björkdahl, O; Sørensen, P G; Hansen, T; Jensen, M R; Gundersen, H J G; Bjørnholm, T

    2006-01-01

    In this paper we present surface modification strategies of boron carbide nanoparticles, which allow for bioconjugation of the transacting transcriptional activator (TAT) peptide and fluorescent dyes. Coated nanoparticles can be translocated into murine EL4 thymoma cells and B16 F10 malignant melanoma cells in amounts as high as 0.3 wt. % and 1 wt. %, respectively. Neutron irradiation of a test system consisting of untreated B16 cells mixed with B16 cells loaded with boron carbide nanoparticles were found to inhibit the proliferative capacity of untreated cells, showing that cells loaded with boron-containing nanoparticles can hinder the growth of neighboring cells upon neutron irradiation. This could provide the first step toward a T cell-guided boron neutron capture therapy.

  11. Understanding Boron through Size-Selected Clusters: Structure, Chemical Bonding, and Fluxionality

    Energy Technology Data Exchange (ETDEWEB)

    Sergeeva, Alina P.; Popov, Ivan A.; Piazza, Zachary A.; Li, Wei-Li; Romanescu, Constantin; Wang, Lai S.; Boldyrev, Alexander I.

    2014-04-15

    Conspectus Boron is an interesting element with unusual polymorphism. While three-dimensional (3D) structural motifs are prevalent in bulk boron, atomic boron clusters are found to have planar or quasi-planar structures, stabilized by localized two-center–two-electron (2c–2e) σ bonds on the periphery and delocalized multicenter–two-electron (nc–2e) bonds in both σ and π frameworks. Electron delocalization is a result of boron’s electron deficiency and leads to fluxional behavior, which has been observed in B13+ and B19–. A unique capability of the in-plane rotation of the inner atoms against the periphery of the cluster in a chosen direction by employing circularly polarized infrared radiation has been suggested. Such fluxional behaviors in boron clusters are interesting and have been proposed as molecular Wankel motors. The concepts of aromaticity and antiaromaticity have been extended beyond organic chemistry to planar boron clusters. The validity of these concepts in understanding the electronic structures of boron clusters is evident in the striking similarities of the π-systems of planar boron clusters to those of polycyclic aromatic hydrocarbons, such as benzene, naphthalene, coronene, anthracene, or phenanthrene. Chemical bonding models developed for boron clusters not only allowed the rationalization of the stability of boron clusters but also lead to the design of novel metal-centered boron wheels with a record-setting planar coordination number of 10. The unprecedented highly coordinated borometallic molecular wheels provide insights into the interactions between transition metals and boron and expand the frontier of boron chemistry. Another interesting feature discovered through cluster studies is boron transmutation. Even though it is well-known that B–, formed by adding one electron to boron, is isoelectronic to carbon, cluster studies have considerably expanded the possibilities of new structures and new materials using the B

  12. Structural characterization of electrodeposited boron

    Indian Academy of Sciences (India)

    Raman spectroscopic examination was carried out to study the nature of bonding and the allotropic form of boron obtained after electrodeposition. The results obtained from transmission electron microscopy showed the presence of nanocrystallites embedded in an amorphous mass of boron. Raman microscopic studies ...

  13. Effects of supplemental boron on growth performance and meat quality in African ostrich chicks.

    Science.gov (United States)

    Wang, Wei; Xiao, Ke; Zheng, Xinting; Zhu, Daiyun; Yang, Zhi; Tang, Juan; Sun, Pengpeng; Wang, Jing; Peng, Kemei

    2014-11-19

    To investigate the effects of boron on growth performance and meat quality, 10-day-old Africa ostrich chicks were randomly divided into 6 groups with 6 replicates in each group. For 80 days, birds in the treatments were fed the same basal diet but given different concentrations of boron-supplemented water. The highest final BW (33.4 ± 0.30 kg), ADFI (376 ± 1.83 g), and ADG (224 ± 1.01 g) appeared in the group receiving 160 mg/L boron (group 4). 160 mg/L boron also decreased drip loss (2.20 ± 0.59), cooking loss (35.3 ± 1.14), and elevated pH value (6.13 ± 0.28) of meat (P boron improved ostrich growth performance and meat quality; however, high concentrations of boron decreased both performance and meat quality.

  14. Electrophoretic deposits of boron on duralumin plates used for measuring neutron flux

    International Nuclear Information System (INIS)

    Lang, F.M.; Magnier, P.; Finck, C.

    1956-01-01

    Preparation of boron thin film deposits of around 1 mg per cm 2 on duralumin plates with a diameter of 8 cm. The boron coated plates for ionization chambers were originally prepared at the CEA by pulverization of boron carbides on sodium silicates. This method is not controlling precisely enough the quantity of boron deposit. Thus, an electrophoretic method is considered for a better control of the quantity of boron deposit in the scope of using in the future boron 10 which is costly and rare. The method described by O. Flint is not satisfying enough and a similar electrophoretic process has been developed. Full description of the method is given as well as explanation of the use of dried methanol as solvent, tannin as electrolyte and magnesium chloride to avoid alumina formation. (M.P.)

  15. Effect of the powder particle size on the wear behavior of boronized AISI 304 stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Guenen, Ali [Mustafa Kemal Univ., Hatay (Turkey). Dept. of Metallurgy and Material Engineering; Kuecuek, Yilmaz; Oege, Mecit; Goek, M. Sabri [Bartin Univ. (Turkey). Dept. of Mechanical Engineering; Er, Yusuf [Firat Univ., Elazig (Turkey); Cay, V. Veli [Dicle Univ., Diyarbakir (Turkey). Civil Aviation Higher School

    2015-06-01

    In this study, the AISI 304 steel specimens were boronized with nanoboron of the size of 10 50 nm and commercial Ekabor 3 powders (<1400 μm) at 950 C to 1000 C for 2 h and 4 h. Boronized steel specimens were characterized via SEM, microhardness and XRD analyses. Abrasive wear behavior of the specimens, boronized at different temperatures and treatment durations, were examined. The fixed ball micro-abrasion tests were carried out using the abrasive slurry, prepared with different SiC powder particle sizes on the boronized specimens at different rotational speeds. The specimens boronized with nanoboron powders exhibited a higher hardness and abrasive wear resistance than the samples boronized with the Ekabor 3 powders.

  16. Optical properties of boron carbide near the boron K edge evaluated by soft-x-ray reflectometry from a Ru/B(4)C multilayer.

    Science.gov (United States)

    Ksenzov, Dmitriy; Panzner, Tobias; Schlemper, Christoph; Morawe, Christian; Pietsch, Ullrich

    2009-12-10

    Soft-x-ray Bragg reflection from two Ru/B(4)C multilayers with 10 and 63 periods was used for independent determination of both real and imaginary parts of the refractive index n = 1 - delta + ibeta close to the boron K edge (approximately 188 eV). Prior to soft x-ray measurements, the structural parameters of the multilayers were determined by x-ray reflectometry using hard x rays. For the 63-period sample, the optical properties based on the predictions made for elemental boron major deviations were found close to the K edge of boron for the 10-period sample explained by chemical bonding of boron to B(4)C and various boron oxides.

  17. Hydrolytic Stability of Boronate Ester-Linked Covalent Organic Frameworks

    KAUST Repository

    Li, Huifang

    2018-01-30

    The stability of covalent organic frameworks (COFs) is essential to their applications. However, the common boronate ester-linked COFs are susceptible to attack by nucleophiles (such as water molecules) at the electron-deficient boron sites. To provide an understanding of the hydrolytic stability of the representative boronate ester-linked COF-5 and of the associated hydrolysis mechanisms, density functional theory (DFT) calculations were performed to characterize the hydrolysis reactions of the molecule formed by the condensation of 1,4-phenylenebis(boronic acid) (PBBA) and 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP) monomers; two cases were considered, one dealing with the freestanding molecule and the other with the molecule interacting with COF layers. It was found that the boronate ester (B–O) bond dissociation, which requires one H2O molecule, has a relatively high energy barrier of 22.3 kcal mol−1. However, the presence of an additional H2O molecule significantly accelerates hydrolysis by reducing the energy barrier by a factor of 3. Importantly, the hydrolysis of boronate ester bonds situated in a COF environment follows reaction pathways that are different and have increased energy barriers. These results point to an enhanced hydrolytic stability of COF-5 crystals.

  18. Boron isotope fractionation in column chromatography with glucamine type fibers

    International Nuclear Information System (INIS)

    Sonoda, Akinari; Makita, Yoji; Hirotsu, Takahiro

    2008-01-01

    Glucamine type polymers have specific affinity toward boric acid and borate ion. Among them, Chelest Fiber GRY-L showed larger fractionation for boron isotopes than other polymers in our previous study. For this study, we used Chelest Fibers with different fiber lengths (1.0 mm, 0.5 mm, and 0.3 mm) as column packing materials to perform chromatographic separation of boron isotopes. The shorter fiber has larger packing density when packed into the column using a dry method. The 0.3-mm-long fiber has a larger backpressure than fibers of other lengths. Boron adsorption capacities were measured using the breakthrough operation. At this time, the 0.5-mm-long fiber showed the highest capacity. When we measured the isotope ratio profile for fibers of different length using column chromatography, 0.5-mm-long fibers displayed the highest boron isotope fractionation. The 0.5-mm-long fiber is promising as a packing material of column chromatography for boron isotope separation. We also changed operation methods. The lower eluent concentration and the slower flow rate are suitable for boron isotope separation. (author)

  19. A high boronate avidity monolithic capillary for the selective enrichment of trace glycoproteins.

    Science.gov (United States)

    Li, Daojin; Li, Yang; Li, Xinglin; Bie, Zijun; Pan, Xianghua; Zhang, Qian; Liu, Zhen

    2015-03-06

    Boronate affinity materials, as effective sample enrichment sorbents for glycoproteomic analysis, have attracted increasing attention in recent years. However, most of boronate affinity materials suffer from an apparent limitation, limited binding strength. As a result, extraction of glycoproteins of trace concentration is rather difficult or impossible. In this study, we present a high boronate avidity monolithic capillary. Branched polyethyleneimine (PEI) was used as a scaffold to amplify the number of boronic acid moieties. While 2,4-difluoro-3-formyl-phenylboronic acid (DFFPBA), which exhibited ultrahigh affinity toward cis-diol-containing compounds, was employed as an affinity ligand. Due to the PEI-assisted synergistic multivalent binding, the monolithic column exhibited high boronate avidity toward glycoproteins, with binding constants of 10(-6)-10(-7)M. Such binding strength was the highest among already reported boronic acid-functionalized materials that can be used for glycoproteomic analysis. Besides, the boronate avidity monolithic column exhibited one additional beneficial feature, lowered binding pH (≥6.5). These features greatly favored the selective enrichment of trace glycoproteins from real samples. The feasibility for practical applications was demonstrated with the selective enrichment of trace glycoproteins in human saliva. As compared with other boronate avidity/affinity materials, the boronate avidity monolithic capillary exhibited the best performance. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Functionalized boron nitride nanotubes

    Science.gov (United States)

    Sainsbury, Toby; Ikuno, Takashi; Zettl, Alexander K

    2014-04-22

    A plasma treatment has been used to modify the surface of BNNTs. In one example, the surface of the BNNT has been modified using ammonia plasma to include amine functional groups. Amine functionalization allows BNNTs to be soluble in chloroform, which had not been possible previously. Further functionalization of amine-functionalized BNNTs with thiol-terminated organic molecules has also been demonstrated. Gold nanoparticles have been self-assembled at the surface of both amine- and thiol-functionalized boron nitride Nanotubes (BNNTs) in solution. This approach constitutes a basis for the preparation of highly functionalized BNNTs and for their utilization as nanoscale templates for assembly and integration with other nanoscale materials.

  1. Boron Activated Neutron Thermometer

    Energy Technology Data Exchange (ETDEWEB)

    Lapsley, A. C. [Argonne National Lab. (ANL), Argonne, IL (United States). Instrument Research & Development

    1952-01-09

    The Brown Instrument Division of Minneapolis-Honeywell Regulator Co. have been making pilot models of boron coated neutron sensitive thermopiles, which show considerable promise of being effective indicators of slow neutron flux. Their loss in sensitivity in a year of operation in the maximum flux of CP-6 calculates to be less than 6 per cent. When used as rooftop indicators, the ratio of the signal of the two units would change by about 2 per cent in a year's time.

  2. Quantitative analysis of proton boron fusion therapy (PBFT) in various conditions

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Joo-Young; Yoon, Do-Kun; Suh, Tae Suk [College of Medicine, Catholic University of Korea, Seoul (Korea, Republic of)

    2015-05-15

    From the theoretical point of view, the PBFT has some strong advantages over currently existing radiotherapy methods. First, boron-based tumor targeting is required prior to performing the treatments such as boron-neutron capture therapy (BNCT). Tumor targeting should be performed before the BNCT by injecting the boronate compound. If boron is not taken up by the normal tissue, the normal tissue can be spared the irradiation by alpha particles. When boron uptake occurs in the target region, selective therapy is possible by neutron capture reaction of labeled boron particles in the target region. Likewise, when boron is distributed in the tumor region for the PBFT, the proposed method can represent a more critical discriminative therapy than either the BNCT or conventional particle therapy. In the conventional proton therapy, in order to deliver a dose to a tumor, the proton beam energy has to be adjusted along the tumor region (e.g., shape and depth). The proton therapy aims at delivering the maximal dose to the tumor by using protons only. In this study, the effectiveness of the PBFT with respect to several physical parameters was evaluated quantitatively by using Monte Carlo simulations. We confirmed that the PBFT can be used to perform critical discriminative therapy. Also, the results of our studies can be used for constructing the PFBT dose database that can be utilized in treatment planning systems (TPSs)

  3. Boron, calcium and magnesium in Kavaratti lagoon water, Lakshadweep Archipelago

    Digital Repository Service at National Institute of Oceanography (India)

    Nasnolkar, C.M.; Salkar, V.R.; Shirodkar, P.V.; Abidi, S.A.H.

    1228.8 to 1319.8 mg kg sup(-1) (av. 1280.19 mg kg sup(-1)) and the salinity varied from 35.01 to 35.10 x 10 sup(-3) (av. 35.04 x 10 sup(-3)). The ratios of boron, calcium and magnesium to chlorinity in the lagoon water showed wide variation and were...

  4. The long march towards an EU power target model (1.0)... and the journey towards a 2030 target model (2.0)

    OpenAIRE

    GLACHANT, Jean-Michel

    2016-01-01

    The European Union took more than 20 years to define a common market design for its internal electricity market: a European Power Target Model. And, a further 10 years to fully implement it. In the meantime, the reference generation set of that model has shifted from the Combined Cycle Gas Turbine (CCGT) burning gas to RES units transforming intermittent natural resources. Could the existing EU target model continue to work well for the short-term operation and long-term investment? If not, c...

  5. Angular distributions of four proton groups from the b10(d, p)b11 reaction

    NARCIS (Netherlands)

    Endt, P.M.; Paris, C.H.; Jongerius, H.M.; Valckx, F.P.G.

    Angular distributions have been measured of four proton groups from the B10(d, p)B11 reaction corresponding to transitions to the groundstate (group (0)) and the three lowest excited states of B11 (groups (1), (2) and (3)). A thin target of natural boron was bombarded with 310 keV deuterons and

  6. Mathematical modeling based evaluation and simulation of boron removal in bioelectrochemical systems.

    Science.gov (United States)

    Ping, Qingyun; Abu-Reesh, Ibrahim M; He, Zhen

    2016-11-01

    Boron removal is an arising issue in desalination plants due to boron's toxicity. As an emerging treatment concept, bioelectrochemical systems (BES) can achieve potentially cost-effective boron removal by taking advantage of cathodic-produced alkali. Prior studies have demonstrated successful removal of boron in microbial desalination cells (MDCs) and microbial fuel cells (MFCs), both of which are representative BES. Herein, mathematical models were developed to further evaluate boron removal by different BES and understand the key operating factors. The models delivered very good prediction of the boron concentration in the MDC integrated with Donnan Dialysis (DD) system with the lowest relative root-mean-square error (RMSE) of 0.00%; the predication of the MFC performance generated the highest RMSE of 18.55%. The model results of salt concentration, solution pH, and current generation were well fitted with experimental data for RMSE values mostly below 10%. The long term simulation of the MDC-DD system suggests that the accumulation of salt in the catholyte/stripping solution could have a positive impact on the removal of boron due to osmosis-driven convection. The current generation in the MDC may have little influence on the boron removal, while in the MFC the current-driven electromigration can contribute up to 40% of boron removal. Osmosis-induced convection transport of boron could be the major driving force for boron removal to a low level 22.2 in order to avoid boron accumulation in the anolyte effluent. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Rice and wheat yield improvement by the application of boron in salt affected soils

    International Nuclear Information System (INIS)

    Mehdi, S.M.; Sarfraz, M.; Hassan, N.M.; Hassan, W.

    2007-01-01

    In recent past studies on wheat, rice and fruit plant showed that fairly large percentage of soils and crops are deficient in boron. Several times a question rose to study the boron responses in a cropping system to see the residual effect of boron. With the objective in mind, a field experiment was conducted at two sites in saline sodic soils to see the rice and wheat crops response to boron. Boron was applied to rice at the rate of 0.25, 0.50, 1.0, 1.5, and 2.0 Kg ha/sub -1/ as sodium tetra borate. The results showed that both paddy and straw yields increased with the increasing rates of boron and highest yield was obtained from 2 Kg ha/sub -l/. After harvesting of rice crop wheat was sown in the same layout. The treatments were divided into two equal portions. Boron was applied to one portion at the same rates as to rice while remaining half remained as such to study the residual effect of B on wheat. The results showed that grain anti straw yields increased with increasing rates of boron. In case of untreated plots to see the residual effect grain and straw yield increased with increasing rates of boron applied to rice. It was concluded that B applied to rice did show residual effect to the following wheat crop. Therefore, there is no need to apply B to following crop when B is applied to the previous crop. (author)

  8. Pairwise cobalt doping of boron carbides with cobaltocene

    Science.gov (United States)

    Ignatov, A. Yu.; Losovyj, Ya. B.; Carlson, L.; LaGraffe, D.; Brand, J. I.; Dowben, P. A.

    2007-10-01

    We have performed Co K-edge x-ray absorption fine structure and x-ray absorption near edge structure measurements of Co-doped plasma enhanced chemical vapor phase deposition (PECVD) grown "C2B10Hx" semiconducting boron carbides, using cobaltocene. Cobalt does not dope PECVD grown boron carbides as a random fragment of the cobaltocene source gas. The Co atoms are fivefold boron coordinated (R=2.10±0.02Å) and are chemically bonded to the icosahedral cages of B10CHx or B9C2Hy. Pairwise Co doping occurs, with the cobalt atoms favoring sites some 5.28±0.02Å apart.

  9. Boron isotopes and groundwater pollution

    International Nuclear Information System (INIS)

    Vengosh, A.

    1999-01-01

    Boron can be used as a tracer in ground water because of its high solubility in aqueous solutions, natural abundance in all waters, and the lack of effects by evaporation, volatilisation, oxidation-reduction reactions. Since the boron concentrations in pristine ground waters are generally low and contaminant sources are usually enriched in boron, the δ 11 B of groundwater is highly sensitive to the impact of contamination. The large isotopic variations of the potential sources can be used to trace the origin of the contamination and to reconstruct mixing and flow paths

  10. Lattice dynamics of α boron and of boron carbide

    International Nuclear Information System (INIS)

    Vast, N.

    1999-01-01

    The atomic structure and the lattice dynamics of α boron and of B 4 C boron carbide have been studied by Density Functional Theory (D.F.T.) and Density Functional Perturbation Theory (D.F.P.T.). The bulk moduli of the unit-cell and of the icosahedron have been investigated, and the equation of state at zero temperature has been determined. In α boron, Raman diffusion and infrared absorption have been studied under pressure, and the theoretical and experimental Grueneisen coefficients have been compared. In boron carbide, inspection of the theoretical and experimental vibrational spectra has led to the determination of the atomic structure of B 4 C. Finally, the effects of isotopic disorder have been modeled by an exact method beyond the mean-field approximation, and the effects onto the Raman lines has been investigated. The method has been applied to isotopic alloys of diamond and germanium. (author)

  11. An accelerator-based epithermal photoneutron source for boron neutron capture therapy

    International Nuclear Information System (INIS)

    Mitchell, H.E.

    1996-04-01

    Boron neutron capture therapy is an experimental binary cancer radiotherapy modality in which a boronated pharmaceutical that preferentially accumulates in malignant tissue is first administered, followed by exposing the tissue in the treatment volume to a thermal neutron field. Current usable beams are reactor-based but a viable alternative is the production of an epithermal neutron beam from an accelerator. Current literature cites various proposed accelerator-based designs, most of which are based on proton beams with beryllium or lithium targets. This dissertation examines the efficacy of a novel approach to BNCT treatments that incorporates an electron linear accelerator in the production of a photoneutron source. This source may help to resolve some of the present concerns associated with accelerator sources, including that of target cooling. The photoneutron production process is discussed as a possible alternate source of neutrons for eventual BNCT treatments for cancer. A conceptual design to produce epithermal photoneutrons by high photons (due to bremsstrahlung) impinging on deuterium targets is presented along with computational and experimental neutron production data. A clinically acceptable filtered epithermal neutron flux on the order of 10 7 neutrons per second per milliampere of electron current is shown to be obtainable. Additionally, the neutron beam is modified and characterized for BNCT applications by employing two unique moderating materials (an Al/AlF 3 composite and a stacked Al/Teflon design) at various incident electron energies

  12. An accelerator-based epithermal photoneutron source for boron neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Hannah E. [Georgia Inst. of Technology, Atlanta, GA (United States)

    1996-04-01

    Boron neutron capture therapy is an experimental binary cancer radiotherapy modality in which a boronated pharmaceutical that preferentially accumulates in malignant tissue is first administered, followed by exposing the tissue in the treatment volume to a thermal neutron field. Current usable beams are reactor-based but a viable alternative is the production of an epithermal neutron beam from an accelerator. Current literature cites various proposed accelerator-based designs, most of which are based on proton beams with beryllium or lithium targets. This dissertation examines the efficacy of a novel approach to BNCT treatments that incorporates an electron linear accelerator in the production of a photoneutron source. This source may help to resolve some of the present concerns associated with accelerator sources, including that of target cooling. The photoneutron production process is discussed as a possible alternate source of neutrons for eventual BNCT treatments for cancer. A conceptual design to produce epithermal photoneutrons by high photons (due to bremsstrahlung) impinging on deuterium targets is presented along with computational and experimental neutron production data. A clinically acceptable filtered epithermal neutron flux on the order of 107 neutrons per second per milliampere of electron current is shown to be obtainable. Additionally, the neutron beam is modified and characterized for BNCT applications by employing two unique moderating materials (an Al/AlF3 composite and a stacked Al/Teflon design) at various incident electron energies.

  13. New Small LWR Core Designs using Particle Burnable Poisons for Low Boron Concentration

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Ho Seong; Hwang, Dae Hee; Hong, Ser Gi [Kyung Hee University, Yongin (Korea, Republic of)

    2015-05-15

    The soluble boron has two major important roles in commercial PWR operations : 1) the control of the long-term reactivity to maintain criticality under normal operation, and 2) the shutdown of the reactor under accidents. However, the removal of the soluble boron gives several advantages in SMRs (Small Modular Reactor). These advantages resulted from the elimination of soluble boron include the significant simplification of nuclear power plant through the removal of pipes, pumps, and purification systems. Also, the use of soluble boron mitigates corrosion problems on the primary coolant loop. Furthermore, the soluble boron-free operation can remove an inadvertent boron dilution accident (BDA) which can lead to a significant insertion of positive reactivity. From the viewpoint of core physics, the removal of soluble boron or reduction of soluble boron concentration makes the moderator temperature coefficient (MTC) more negative. From the core design studies using new fuel assemblies, it is shown that the cores have very low critical soluble boron concentrations less than 500ppm, low peaking factors within the design targets, strong negative MTCs over cycles, and large enough shutdown margins both at BOC and EOC. However, the present cores have relatively low average discharge burnups of ∼ 30MWD/kg leading to low fuel economy because the cores use lots of non-fuel burnable poison rods to achieve very low critical boron concentrations. So, in the future, we will perform the trade-off study between the fuel discharge burnup and the boron concentrations by changing fuel assembly design and the core loading pattern.

  14. Hydrogen detection by a boron sheet: A theoretical study .

    Science.gov (United States)

    Dominguez, F. Javier; Novotny, Michal; Krstic, Predrag S.

    A single boron sheet is now considered as a new nanomaterial with promising applications in electronics and as a sensor device. In this study we present quantum-classical molecular dynamic (QCMD) calculation of reflection, adsorption, and transmission processes of hydrogen impacting at energy in range 0.25 to 100 eV on a single boron sheet. Quantum-mechanical component of our QCMD approach is self-consistent charge tight binding density functional theory method (SCC-DFTB,). We consider the corrugated boron sheet as our target, created experimentally, and compare our results with those reported for graphene, showing noticeable differences. Research supported by CONACyT postdoctoral scholarship to FJD and the Fulbright Comission (Grant 15160939) to MN. Results were obtained using the LI-red cluster at IACS.

  15. A new and effective approach to boron removal by using novel boron-specific fungi isolated from boron mining wastewater.

    Science.gov (United States)

    Taştan, Burcu Ertit; Çakir, Dilara Nur; Dönmez, Gönül

    2016-01-01

    Boron-resistant fungi were isolated from the wastewater of a boron mine in Turkey. Boron removal efficiencies of Penicillium crustosum and Rhodotorula mucilaginosa were detected in different media compositions. Minimal Salt Medium (MSM) and two different waste media containing molasses (WM-1) or whey + molasses (WM-2) were tested to make this process cost effective when scaled up. Both isolates achieved high boron removal yields at the highest boron concentrations tested in MSM and WM-1. The maximum boron removal yield by P. crustosum was 45.68% at 33.95 mg l(-1) initial boron concentration in MSM, and was 38.97% at 42.76 mg l(-1) boron for R. mucilaginosa, which seemed to offer an economically feasible method of removing boron from the effluents.

  16. Density functional calculations of hydrogen adsorption on boron nanotubes and boron sheets

    Science.gov (United States)

    Cabria, I.; López, M. J.; Alonso, J. A.

    2006-02-01

    Hydrogen adsorption on the recently discovered boron nanotubes, BNTs, and on boron sheets is investigated by density functional calculations. Both molecular physisorption and dissociative atomic chemisorption are considered. The geometric and electronic structures of BNTs and boron sheets have been elucidated. These two novel boron structures present buckled surfaces with alternating up and down rows of B atoms, with a large buckling height of about 0.8 Å. The buckled structures are about 0.20 eV/atom more stable than the corresponding flat ones. However, the helicity of some BNTs does not allow for the formation of alternating up and down B rows in the surface and, therefore, these nanotubes have flat surfaces. The buckled and flat nanostructures have different geometric and bonding characteristics, but both are metallic. Molecular hydrogen physisorption energies are about 30-60 meV/molecule on boron sheets and nanotubes, actually lower than in graphene and in carbon nanotubes and far from the energies of 300-400 meV/molecule necessary for efficient hydrogen storage at room temperature and moderate pressures for onboard automotive applications. Chemisorption binding energies on BNTs are about 2.4-2.9 eV/H atom, similar to the ones obtained in CNTs. Finally, the energy barrier from molecular physisorption to dissociative chemisorption of hydrogen is about 1.0 eV /molecule. Therefore, the calculations predict physisorption as the leading adsorption mechanism of hydrogen at moderate temperatures and pressures. The expected hydrogen adsorption capacity of these novel B materials is even smaller than that of CNTs.

  17. Boron, phosphorus, and gallium determination in silicon crystals doped with gallium

    International Nuclear Information System (INIS)

    Shklyar, B.L.; Dankovskij, Yu.V.; Trubitsyn, Yu.V.

    1989-01-01

    When studying IR transmission spectra of silicon doped with gallium in the range of concentrations 1 x 10 14 - 5 x 10 16 cm -3 , the possibility to quantity at low (∼ 20 K) temperatures residual impurities of boron and phosphorus is ascertained. The lower determination limit of boron is 1 x 10 12 cm -3 for a sample of 10 nm thick. The level of the impurities in silicon crystals, grown by the Czochralski method and method of crucible-free zone melting, is measured. Values of boron and phosphorus concentrations prior to and after their alloying with gallium are compared

  18. Multidimensional potential of boron-containing molecules in ...

    Indian Academy of Sciences (India)

    Administrator

    10 all due to the acceptor effect of B. Boron is an excellent element for studying the spin distribution in paramagnetic species because both stable isotopes. 10 ..... and drug therapies. The reports of enhanced water solubility of CNTs through side-wall derivatisation with biologically important moieties. 76–93 caused.

  19. Irradiation Effects in Fortiweld Steel Containing Different Boron Isotopes

    International Nuclear Information System (INIS)

    Grounes, M.

    1967-07-01

    Tensile specimens and miniature impact specimens of the low alloyed pressure vessel steel Fortiweld have been irradiated at 265 deg C in R2 to two neutron doses, 6.5 x 10 18 n/cm 2 (> 1 MeV) and 4 x 10 19 n/cm 2 (thermal) and also 9.0 x 10 18 n/cm 2 (> 1 MeV) and 6 x 10 19 n/cm 2 (thermal). Material from three laboratory melts, in which the boron consisted of 10 B, 11 B and natural boron respectively, were investigated. The results both of tensile tests and impact tests with miniature impact specimens show that the 10 B-alloyed material was changed more and the 11 B-alloyed material was changed less than the material containing natural boron. At the higher neutron dose the increase in yield strength (0.2 % offset yield strength) was 11 kg/mm in the 10 B containing material compared to 5 kg/mm in the 11 B-containing material. The decrease in total elongation was 5 and 0 percentage units respectively. The transition temperature was increased 190 deg C at the higher neutron dose in the 10 B-alloyed material, 40 deg C in the 11 B-alloyed material and 80 deg C in the material containing natural boron

  20. Nano boron nitride flatland.

    Science.gov (United States)

    Pakdel, Amir; Bando, Yoshio; Golberg, Dmitri

    2014-02-07

    Recent years have witnessed many breakthroughs in research on two-dimensional (2D) nanomaterials, among which is hexagonal boron nitride (h-BN), a layered material with a regular network of BN hexagons. This review provides an insight into the marvellous nano BN flatland, beginning with a concise introduction to BN and its low-dimensional nanostructures, followed by an overview of the past and current state of research on 2D BN nanostructures. A comprehensive review of the structural characteristics and synthetic routes of BN monolayers, multilayers, nanomeshes, nanowaves, nanoflakes, nanosheets and nanoribbons is presented. In addition, electronic, optical, thermal, mechanical, magnetic, piezoelectric, catalytic, ecological, biological and wetting properties, applications and research perspectives for these novel 2D nanomaterials are discussed.

  1. Biocompatibility of functionalized boron phosphate (BPO4) nanoparticles for boron neutron capture therapy (BNCT) application.

    Science.gov (United States)

    Achilli, Cesare; Grandi, Stefania; Ciana, Annarita; Guidetti, Gianni F; Malara, Alessandro; Abbonante, Vittorio; Cansolino, Laura; Tomasi, Corrado; Balduini, Alessandra; Fagnoni, Maurizio; Merli, Daniele; Mustarelli, Piercarlo; Canobbio, Ilaria; Balduini, Cesare; Minetti, Giampaolo

    2014-04-01

    Boron neutron capture therapy (BNCT) is a radiotherapy treatment based on the accumulation in the tumor of a (10)B-containing drug and subsequent irradiation with low energy neutrons, which bring about the decay of (10)B to (7)Li and an α particle, causing the death of the neoplastic cell. The effectiveness of BNCT is limited by the low delivery and accumulation of the used boron-containing compounds. Here we report the development and the characterization of BPO4 nanoparticles (NPs) as a novel possible alternative drug for BNCT. An extensive analysis of BPO4 NP biocompatibility was performed using both mature blood cells (erythrocytes, neutrophils and platelets) and a model of hematopoietic progenitor cells. A time- and concentration-dependent cytotoxicity study was performed on neoplastic coloncarcinoma and osteosarcoma cell lines. BPO4 functionalization with folic acid, introduced to improve the uptake by tumor cells, appeared to effectively limit the unwanted effects of NPs on the analyzed blood components. Boron neutron capture therapy (BNCT) is a radiotherapy treatment modality based on the accumulation of a (10)B-containing drug and subsequent irradiation with low energy neutrons, inducing the decay of (10)B to (7)Li and an α particle, causing neoplastic cell death. This team of authors reports on a folic acid functionalized BPO4 nanoparticle with improved characteristics compared with conventional BNCT approaches, as demonstrated in tumor cell lines, and hopefully to be followed by translational human studies. © 2014.

  2. Synovectomy by neutron capture in boron

    International Nuclear Information System (INIS)

    Vega C, H.R.

    2002-01-01

    The rheumatoid arthritis is an illness which affect approximately at 3% of the World population. This illness is characterized by the inflammation of the joints which reduces the quality of life and the productivity of the patients. Since, it is an autoimmune illness, the inflammation is due to the overproduction of synovial liquid by the increase in the quantity of synoviocytes. The rheumatoid arthritis does not have a definitive recovery and the patients have three options of treatment: the use of drugs, the surgery and the radio synovectomy. The synovectomy by neutron capture in Boron is a novel proposal of treatment of the rheumatoid arthritis that consists in using a charged compound with Boron 10 that is preferently incorporated in the synoviocytes and to a less extent in the rest of surrounding tissues of the joint. Then, the joint is exposed to a thermal neutron field that induces the reaction (n, α) in the 10 B. the products of this reaction place their energy inside synoviocytes producing their reduction and therefore the reduction of the joint inflammation. Since it is a novel procedure, the synovectomy by neutron capture in boron has two problems: the source design and the design of the adequate drug. In this work it has been realized a Monte Carlo study with the purpose to design a moderating medium that with a 239 Pu Be source in its center, produces a thermal neutron field. With the produced neutron spectra, the neutrons spectra and neutron doses were calculated in different sites inside a model of knee joint. In Monte Carlo studies it is necessary to know the elemental composition of all the joint components, for the case of synovia and the synovial liquid this information does not exist in such way that it is supposed that its composition is equal than the water. In this work also it has been calculated the kerma factors by neutrons of synovia and the synovial liquid supposing that their elemental composition are similar to the blood tissue

  3. Iron solubility in highly boron-doped silicon

    International Nuclear Information System (INIS)

    McHugo, S.A.; McDonald, R.J.; Smith, A.R.; Hurley, D.L.; Weber, E.R.

    1998-01-01

    We have directly measured the solubility of iron in high and low boron-doped silicon using instrumental neutron activation analysis. Iron solubilities were measured at 800, 900, 1000, and 1100thinsp degree C in silicon doped with either 1.5x10 19 or 6.5x10 14 thinspboronthinspatoms/cm 3 . We have measured a greater iron solubility in high boron-doped silicon as compared to low boron-doped silicon, however, the degree of enhancement is lower than anticipated at temperatures >800thinsp degree C. The decreased enhancement is explained by a shift in the iron donor energy level towards the valence band at elevated temperatures. Based on this data, we have calculated the position of the iron donor level in the silicon band gap at elevated temperatures. We incorporate the iron energy level shift in calculations of iron solubility in silicon over a wide range of temperatures and boron-doping levels, providing a means to accurately predict iron segregation between high and low boron-doped silicon. copyright 1998 American Institute of Physics

  4. Metal interactions with boron clusters

    International Nuclear Information System (INIS)

    Grimes, R.N.

    1982-01-01

    This book presents information on the following topics: the structural and bonding features of metallaboranes and metallacarboranes; transition-metal derivatives of nido-boranes and some related species; interactions of metal groups with the octahydrotriborate (1-) anion, B 3 H 8 ; metallaboron cage compounds of the main group metals; closo-carborane-metal complexes containing metal-carbon and metal-boron omega-bonds; electrochemistry of metallaboron cage compounds; and boron clusters with transition metal-hydrogen bonds

  5. Boron diffusion in silicon devices

    Science.gov (United States)

    Rohatgi, Ajeet; Kim, Dong Seop; Nakayashiki, Kenta; Rounsaville, Brian

    2010-09-07

    Disclosed are various embodiments that include a process, an arrangement, and an apparatus for boron diffusion in a wafer. In one representative embodiment, a process is provided in which a boric oxide solution is applied to a surface of the wafer. Thereafter, the wafer is subjected to a fast heat ramp-up associated with a first heating cycle that results in a release of an amount of boron for diffusion into the wafer.

  6. Mg-doping experiment and electrical transport measurement of boron nanobelts

    International Nuclear Information System (INIS)

    Kirihara, K.; Hyodo, H.; Fujihisa, H.; Wang, Z.; Kawaguchi, K.; Shimizu, Y.; Sasaki, T.; Koshizaki, N.; Soga, K.; Kimura, K.

    2006-01-01

    We measured electrical conductance of single crystalline boron nanobelts having α-tetragonal crystalline structure. The doping experiment of Mg was carried out by vapor diffusion method. The pure boron nanobelt is a p-type semiconductor and its electrical conductivity was estimated to be on the order of 10 -3 (Ω cm) -1 at room temperature. The carrier mobility of pure boron nanobelt was measured to be on the order of 10 -3 (cm 2 Vs -1 ) at room temperature and has an activation energy of ∼0.19 eV. The Mg-doped boron nanobelts have the same α-tetragonal crystalline structure as the pristine nanobelts. After Mg vapor diffusion, the nanobelts were still semiconductor, while the electrical conductance increased by a factor of 100-500. Transition to metal or superconductor by doping was not observed. - Graphical abstract: SEM micrographs of boron nanobelt after Ni/Au electrode fabrication by electron beam lithography. Display Omitted

  7. Enhanced diffusion of oxygen depending on Fermi level position in heavily boron-doped silicon

    Energy Technology Data Exchange (ETDEWEB)

    Torigoe, Kazuhisa, E-mail: ktorigoe@sumcosi.com; Fujise, Jun; Ono, Toshiaki [Technology Division, Advanced Evaluation and Technology Development Department, SUMCO Corporation, 1-52 Kubara, Yamashiro-cho, Imari, Saga 849-4256 (Japan); Nakamura, Kozo [Department of Communication Engineering, Okayama Prefectural University, 111 Kuboki, Soja, Okayama 719-1197 (Japan)

    2014-11-21

    The enhanced diffusivity of oxygen in heavily boron doped silicon was obtained by analyzing oxygen out-diffusion profile changes found at the interface between a lightly boron-doped silicon epitaxial layer and a heavily boron-doped silicon substrate by secondary ion mass spectrometry. It was found that the diffusivity is proportional to the square root of boron concentration in the range of 10{sup 18 }cm{sup −3}–10{sup 19 }cm{sup −3} at temperatures from 750 °C to 950 °C. The model based on the diffusion of oxygen dimers in double positive charge state could explain the enhanced diffusion. We have concluded that oxygen diffusion enhanced in heavily boron-doped silicon is attributed to oxygen dimers ionized depending on Fermi level position.

  8. Subcellular boron and fluorine distributions with SIMS ion microscopy in BNCT and cancer research

    Energy Technology Data Exchange (ETDEWEB)

    Subhash Chandra

    2008-05-30

    The development of a secondary ion mass spectrometry (SIMS) based technique of Ion Microscopy in boron neutron capture therapy (BNCT) was the main goal of this project, so that one can study the subcellular location of boron-10 atoms and their partitioning between the normal and cancerous tissue. This information is fundamental for the screening of boronated drugs appropriate for neutron capture therapy of cancer. Our studies at Cornell concentrated mainly on studies of glioblastoma multiforme (GBM). The early years of the grant were dedicated to the development of cryogenic methods and correlative microscopic approaches so that a reliable subcellular analysis of boron-10 atoms can be made with SIMS. In later years SIMS was applied to animal models and human tissues of GBM for studying the efficacy of potential boronated agents in BNCT. Under this grant the SIMS program at Cornell attained a new level of excellence and collaborative SIMS studies were published with leading BNCT researchers in the U.S.

  9. Possible alternation of the blood-brain barrier by boron-neutron capture therapy

    International Nuclear Information System (INIS)

    Hatanaka, H.; Moritani, M.; Camillo, M.

    1991-01-01

    In the course of re-assessment of boron-neutron capture therapy (BNCT) for malignant brain tumors, fractionation of neutron irradiation has been proposed. The authors have used BNCT with a single fraction technique during the past 21 years and now decided to study some effects of fractionation. Twenty-two healthy mouse brains were irradiated with thermal neutrons after boron-10 injection (mercaptoundecahydrododecaborate). A second dose of boron-10 was administered and its uptake in the boron-neutron-capture-irradiated brains was determined. A tendency towards increased boron uptake in the moderately BNCT-treated brains was noticed, which may result in increased brain damage if fractionated neutron irradiation is used. (orig.)

  10. Microhardness of boron, titanium, and nitrogen implanted steel

    International Nuclear Information System (INIS)

    Sowa, M.; Szyszko, W.; Sielanko, J.; Glusiec, L.

    1989-01-01

    Mechanically polished steel (1H18N9T) and (15GTM) samples are implanted with boron, titanium, and nitrogen ions, with dose ranging from 10 16 to 10 17 ions/cm 2 . The implantation energy varied from 100 to 250 keV. Implanted samples are heat-treated at 400 to 800 0 C in vacuum. The microhardness of implanted samples is measured by using a Hanneman tester with loads ranging from 2 to 40 g. The influence of annealing temperature on microhardness of the implanted layers is determined. The diffusion of boron from the implanted layers is also investigated by using the secondary ion mass spectrometer. The diffusion coefficients of boron in steel are determined. (author)

  11. Vertex Reconstruction for the 10C(α, α)10C scattering reaction using the Prototype Active-Target Time-Projection Chamber

    Science.gov (United States)

    Ahn, T.; Lai, J.; Bardayan, D. W.; Brodeur, M.; Hall, M.; Hall, O.; Hu, J.; Kolata, J. J.; Long, J.; O'Malley, P.; Ayyad, Y.; Bazin, D.; Beceiro Novo, S.; Bradt, J.; Cortesi, M.; Carpenter, L.; Mittig, W.

    2017-09-01

    The investigation of the importance of α-cluster structure on the proton-rich side of stability in the light nucleus 14O has been investigated using a 10C(α, α)10C scattering reaction. The Prototype Active-Target Time-Projection Chamber was used to provide a He gas target and image charged-particle tracks. The key experimental observables that are needed are the vertex position, which determines the energy at which the reaction occurred. The precision of this vertex position gives the reaction energy uncertainty, which needs to be determined to a few mm. The performance of various algorithms for vertex reconstruction will be presented including their advantages and disadvantages. The impact of the energy resolution on particle identification and determining cross sections for the α-resonant scattering experiment will be presented. This work was supported by U.S. NSF Grant No. PHY 14-19765.

  12. Molecular medicine: Synthesis and in-vivo detection of agents for use in boron neutron capture therapy. Final report, May 1, 1993--April 30, 1996

    International Nuclear Information System (INIS)

    Kabalka, G.W.

    1997-08-01

    During the early stages of this project, the author developed the first whole-body boron MRI technique. They found that, for the first time, information concerning both the location and the quantity of boron present in living tissues could be obtained through the use of magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) respectively. However, it was also discovered that boron MRI was not without problems. Both naturally occurring isotopes of boron (boron-10 and boron-11) possess magnetic moments, making them amenable to MR detection. The author found that there are difficulties in obtaining boron MRI images which are a consequence of the inherently poor magnetic resonance characteristics of the boron nucleus. The magnetogyric ratios of both boron-10 and boron-11 are smaller than those of hydrogen, which makes boron much less sensitive to magnetic resonance detection. In addition, both isotopes of boron posses nuclear electric quadrupole moments which serve to shorten their magnetization relaxation times; this causes the MR signal to broaden and decay rapidly, often before the receiver coils can collect the MR information. The rapid rate of signal decay is enhanced in biological systems which leads to further signal loss and a decrease in the signal to noise ratio (SNR)

  13. Molecular medicine: Synthesis and in-vivo detection of agents for use in boron neutron capture therapy. Final report, May 1, 1993--April 30, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Kabalka, G.W.

    1997-08-01

    During the early stages of this project, the author developed the first whole-body boron MRI technique. They found that, for the first time, information concerning both the location and the quantity of boron present in living tissues could be obtained through the use of magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) respectively. However, it was also discovered that boron MRI was not without problems. Both naturally occurring isotopes of boron (boron-10 and boron-11) possess magnetic moments, making them amenable to MR detection. The author found that there are difficulties in obtaining boron MRI images which are a consequence of the inherently poor magnetic resonance characteristics of the boron nucleus. The magnetogyric ratios of both boron-10 and boron-11 are smaller than those of hydrogen, which makes boron much less sensitive to magnetic resonance detection. In addition, both isotopes of boron posses nuclear electric quadrupole moments which serve to shorten their magnetization relaxation times; this causes the MR signal to broaden and decay rapidly, often before the receiver coils can collect the MR information. The rapid rate of signal decay is enhanced in biological systems which leads to further signal loss and a decrease in the signal to noise ratio (SNR).

  14. Boron Fullerenes: A First-Principles Study

    Directory of Open Access Journals (Sweden)

    Gonzalez Szwacki Nevill

    2007-01-01

    Full Text Available AbstractA family of unusually stable boron cages was identified and examined using first-principles local-density functional method. The structure of the fullerenes is similar to that of the B12icosahedron and consists of six crossing double-rings. The energetically most stable fullerene is made up of 180 boron atoms. A connection between the fullerene family and its precursors, boron sheets, is made. We show that the most stable boron sheets are not necessarily precursors of very stable boron cages. Our finding is a step forward in the understanding of the structure of the recently produced boron nanotubes.

  15. The effect of the boron source composition ratio on the adsorption performance of hexagonal boron nitride without a template

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ning, E-mail: zhangning5832@163.com; Zhang, Tong; Kan, Hongmin; Wang, Xiaoyang; Long, Haibo; Cui, Xingyu

    2015-08-01

    An inexpensive boric acid (H{sub 3}BO{sub 3}) and borax (Na{sub 2}B{sub 4}O{sub 7}·10H{sub 2}O) mix was used as a source of boron with different composition ratios, and urea was used as a nitrogen source, in flowing ammonia atmosphere, for the preparation of hexagonal boron nitride (h-BN) with different micro-morphologies. Under a certain synthesis process, the effects of the molar ratio of borax and boric acid (or simply the boron source composition ratio for short) on the phase composition of the sample were studied; the work also explored the effect of boron source composition ratio on the micro-morphology, adsorption desorption isotherm and specific surface area of the h-BN powder. The main purpose of this work was to determine the optimum composition ratio of preparing spherical mesoporous h-BN and ensure that the micro-mechanism underpinning the formation of spherical mesoporous h-BN was understood. The results showed that at the optimum boron source composition ratio of 1:1, globular mesoporous spheres with a diameter of approximately 600–800 nm could be obtained with the highest pore volume and specific surface area (230.2 m{sup 2}/g). - Graphical abstract: Display Omitted - Highlights: • Spherical h-BN was synthesized by controlling the boron source composition ratio. • Without extra spherical template, solid Na{sub 2}O was equal to a spherical template. • At boron source composition ratio of 1:1, h-BN had best adsorption performance.

  16. Dietary Boron and Hormone Replacement Therapy as Risk Factors for Lung Cancer in Women

    Science.gov (United States)

    Mahabir, S.; Spitz, M. R.; Barrera, S. L.; Dong, Y. Q.; Eastham, C.; Forman, M. R.

    2012-01-01

    Hormone replacement therapy (HRT) may reduce lung cancer risk. Dietary boron may have actions similar to those of HRT; however, no previous study has reported the associations between dietary boron intake and lung cancer risk or the joint effects of boron intake and HRT use on lung cancer risk. The authors examined the associations between boron intake and the joint effects of boron intake and HRT on lung cancer risk in women. In an ongoing case-control study in Houston, Texas (July 1995 through April 2005, end date for this analysis), 763 women were diagnosed with lung cancer, and 838 were matched healthy controls with data on both diet and HRT. Multiple logistic regression analyses were conducted to assess the associations between dietary boron and HRT with lung cancer risk. After adjustment for potential confounders, the odds ratios for lung cancer with decreasing quartiles of dietary boron intake were 1.0, 1.39 (95% confidence interval (CI): 1.02, 1.90), 1.64 (95% CI: 1.20, 2.24), and 1.95 (95% CI: 1.42, 2.68) mg/day, respectively, for all women (ptrend boron intake who used HRT, the odds ratio for lung cancer for low dietary boron intake and no HRT use was 2.07 (95% CI: 1.53, 2.81). Boron intake was inversely associated with lung cancer in women, whereas women who consumed low boron and did not use HRT were at substantial increased odds. PMID:18343880

  17. Boron ion source based on planar magnetron discharge in self-sputtering mode.

    Science.gov (United States)

    Gushenets, V I; Hershcovitch, A; Kulevoy, T V; Oks, E M; Savkin, K P; Vizir, A V; Yushkov, G Yu

    2010-02-01

    An ion source based on a planar magnetron sputtering device with thermally isolated target has been designed and demonstrated. For a boron sputtering target, high target temperature is required because boron has low electrical conductivity at room temperature, increasing with temperature. The target is well-insulated thermally and can be heated by an initial low-current, high-voltage discharge mode. A discharge power of 16 W was adequate to attain the required surface temperature (400 degrees C), followed by transition of the discharge to a high-current, low-voltage mode for which the magnetron enters a self-sputtering operational mode. Beam analysis was performed with a time-of-flight system; the maximum boron ion fraction in the beam is greater than 99%, and the mean boron ion fraction, time-integrated over the whole pulse length, is about 95%. We have plans to make the ion source steady state and test with a bending magnet. This kind of boron ion source could be competitive to conventional boron ion sources that utilize compounds such as BF(3), and could be useful for semiconductor industry application.

  18. Targeting the chemokine receptor CXCR3 and its ligand CXCL10 in the central nervous system

    DEFF Research Database (Denmark)

    Sørensen, Torben Lykke

    2004-01-01

    focuses on the present data regarding CXCL10 (previously known as IP-10) and CXRC3 in multiple sclerosis, since consistent data has suggested that this chemokine/chemokine receptor pair has a pivotal role in leukocyte recruitment into the central nervous system (CNS) in multiple sclerosis....

  19. Interactions of 10.6 GeV/n gold nuclei with light and heavy target nuclei in nuclear emulsion

    International Nuclear Information System (INIS)

    Cherry, M.L.; Denes-Jones, P.

    1994-03-01

    We have investigated the particle production and fragmentation of nuclei participating in the interactions of 10.6 GeV/n gold nuclei in nuclear emulsions. A new criteria has been developed to distinguish between the interactions of these gold nuclei with the light (H, C, N, O) and heavy (Ag, Br) target nuclei in the emulsion. This has allowed separate analyzes of the multiplicity and pseudo-rapidity distributions of the singly charged particles emitted in Au-(H, C, N, O) and Au-(Ag, Br) interactions, as well as of the models of breakup of the projectile and target nuclei. The pseudo-rapidity distributions show strong forward asymmetries, particularly for the interactions with the light nuclei. Heavy target nuclei produce a more severe breakup of the projectile gold nucleus than do the lighter targets. A negative correlation between the number of fragments emitted from the target nuclei and the degree of centrality of the collisions has been observed, which can be attributed to the total destruction of the relatively light target nuclei by these very heavy projectile nuclei. (author). 14 refs, 11 figs, 1 tab

  20. Boron biodistribution study in colorectal liver metastases patients in Argentina.

    Science.gov (United States)

    Cardoso, J; Nievas, S; Pereira, M; Schwint, A; Trivillin, V; Pozzi, E; Heber, E; Monti Hughes, A; Sanchez, P; Bumaschny, E; Itoiz, M; Liberman, S

    2009-07-01

    Ex-situ BNCT for multifocal unresectable liver metastases employing whole or partial autograft techniques requires knowledge of boron concentrations in healthy liver and metastases following perfusion and immersion in Wisconsin solution (W), the procedure employed for organ preservation during ex-situ irradiation. Measurements of boron concentration in blood, liver and metastases following an intravenous infusion of BPA-F in five colorectal liver metastases patients scheduled for surgery were performed. Tissue samples were evaluated for boron content pre and post perfusion and immersion in W. Complementary histological studies were performed. The data showed a dose-dependent BPA uptake in liver, a boron concentration ratio liver/blood close to 1 and a wide spread in the metastases/liver concentration ratios in the range 0.8-3.6, partially attributable to histological variations between samples. Based on the boron concentrations and dose considerations (liver or =40 Gy-Eq) at the RA-3 thermal neutron facility (mean flux of about (6+/-1) x 10(9) n cm(-2)s(-1)), ex-situ treatment of liver metastases at RA-3 would be feasible.

  1. Microwave digestion techniques applied to determination of boron by ICP-AES in BNCT program

    International Nuclear Information System (INIS)

    Farias, Silvia S.; Di Santo, Norberto R.; Garavaglia, Ricardo N.; Pucci, Gladys N.; Batistoni, Daniel A.; Schwint, Amanda E.

    1999-01-01

    Recently, boron neutron capture therapy (BNCT) has merged as an interesting option for the treatment of some kind of tumors where established therapies show no success. A molecular boronated species, enriched in 10 B is administrated to the subject; it localizes in malignant tissues depending the kind of tumor and localization. Therefore, a very important fact in BNCT research is the detection of boron at trace or ultra trace levels precisely and accurately. This is extremely necessary as boronated species do localize in tumoral tissue and also localize in liver, kidney, spleen, skin, membranes. By this way, before testing a boronated species, it is mandatory to determine its biodistribution in a statistically meaning population, that is related with managing of a great number of samples. In the other hand, it is necessary to exactly predict when to begin the irradiation and to determine the magnitude of radiation to obtain the desired radiological dose for a specified mean boron concentration. This involves the determination of boron in whole blood, which is related with boron concentration in the tumor object of treatment. The methodology selected for the analysis of boron in whole blood and tissues must join certain characteristics: it must not be dependant of the chemical form of boron, it has to be fast and capable to determine boron accurately and precisely in a wide range of concentrations. The design and validation of experimental models involving animals in BNCT studies and the determination of boron in blood of animals and subjects upon treatment require reliable analytical procedures to determine boron quantitatively in those biologic materials. Inductively coupled plasma-atomic emission spectrometry (ICP-AES) using pneumatic nebulization is one of the most promising methods for boron analysis, but the sample must be liquid and have low solid concentration. In our case, biological tissues and blood, it is mandatory to mineralize and/or dilute samples

  2. Commercial Clinical Application of Boron Neutron Capture Therapy

    International Nuclear Information System (INIS)

    1999-01-01

    CRADA No. 95-CR-09 among the LITCO--now Bechtel BWXT Idaho, LLC; a private company, Neutron Therapies Limited Liability Company, NTL formerly Ionix Corporation; and Washington State University was established in 1996 to further the development of BNCT. NTL has established a laboratory for the synthesis, under US FDA approved current Good Manufacturing Practices (cGMP) guidelines, of key boron intermediates and final boron agents for BNCT. The company has focused initially on the development of the compound GB-10 (Na 2 B 10 H 10 ) as the first boron agent of interest. An Investigational New Drug (IND) application for GB-10 has been filed and approved by the FDA for a Phase I human biodistribution trial in patients with non-small cell lung cancer and glioblastoma multiforme at UW under the direction of Professor Keith Stelzer, Principal Investigator (PI). These trials are funded by NTL under a contract with the UW, Department of Radiation Oncology, and the initial phases are nearing completion. Initial results show that boron-10 concentrations on the order of 100 micrograms per gram (100 ppm) can be achieved and maintained in blood with no indication of toxicity

  3. Epigenetic modification of miR-10a regulates renal damage by targeting CREB1 in type 2 diabetes mellitus

    International Nuclear Information System (INIS)

    Shan, Qun; Zheng, Guihong; Zhu, Aihua; Cao, Li; Lu, Jun; Wu, Dongmei; Zhang, ZiFeng; Fan, Shaohua; Sun, Chunhui; Hu, Bin; Zheng, Yuanlin

    2016-01-01

    Emerging evidence has shown that microRNA-mediated gene expression modulation plays a crucial role in the pathogenesis of type 2 diabetes mellitus, but the novel miRNAs involved in type 2 diabetes and its functional regulatory mechanisms still need to be determined. In this study, we assessed the role of miR-10a in extracellular matrix accumulation in the kidney of diabetic mellitus induced by combining administration of chronic high fat diet (HFD) and low dosage of streptozotocin (STZ, 35 mg/kg). Here, we found that HFD/STZ administration decreased the level of microRNA (miR-10a) expression in ICR strain mice. Overexpression of miR-10a alleviated the increased ratio of urine albumin-to-creatinine (ACR) ratio of HFD/STZ mice. In contrast, knockdown of miR-10a increased the ratio of kidney ACR in naïve mice. Furthermore, cAMP response element binding protein 1 (CREB1) was validated as a target of miR-10a in vitro and in vivo. CREB1 and its downstream fibronectin (FN, extracellular matrix) were increased in HFD/STZ-treated mice, which was reversed by kidney miR-10a overexpression. The content of CREB1 and FN was increased by miR-10a knockdown in kidney of naïve mice. Furthermore, histone deacetylase 3 (HDAC3) was revealed to be increased in kidney of HFD/STZ mice, accompanied with the augmentation of ACR ratio and FN level. Knockdown of HDAC3 with siRNA significantly caused the increase of miR-10a, resulting in the decrease in CREB1 and FN expression in kidney of HFD/STZ mice. Contrarily, HDAC3 overexpression mediated by lentivirus decreased miR-10a content, and enhanced ACR value, CREB1 and FN formation in naïve mice. Collectively, these results elucidate that HDAC3/miR-10a/CREB1 serves as a new mechanism underlying kidney injury, providing potential therapeutic targets in type 2 diabetes. - Highlights: • Diabetes induces the decrease of miR-10a level in the kidney. • MiR-10a overexpression improves kidney damage of diabetes. • MiR-10a targeting CREB1/FN

  4. Structure and superconductivity of isotope-enriched boron-doped diamond.

    Science.gov (United States)

    Ekimov, Evgeny A; Sidorov, Vladimir A; Zoteev, Andrey V; Lebed, Julia B; Thompson, Joe D; Stishov, Sergey M

    2008-12-01

    Superconducting boron-doped diamond samples were synthesized with isotopes of 10 B, 11 B, 13 C and 12 C. We claim the presence of a carbon isotope effect on the superconducting transition temperature, which supports the 'diamond-carbon'-related nature of superconductivity and the importance of the electron-phonon interaction as the mechanism of superconductivity in diamond. Isotope substitution permits us to relate almost all bands in the Raman spectra of heavily boron-doped diamond to the vibrations of carbon atoms. The 500 cm -1 Raman band shifts with either carbon or boron isotope substitution and may be associated with vibrations of paired or clustered boron. The absence of a superconducting transition (down to 1.6 K) in diamonds synthesized in the Co-C-B system at 1900 K correlates with the small boron concentration deduced from lattice parameters.

  5. Preparation and characterization of Boron carbide nanoparticles for use as a novel agent in T cell-guided boron neutron capture therapy.

    Science.gov (United States)

    Mortensen, M W; Sørensen, P G; Björkdahl, O; Jensen, M R; Gundersen, H J G; Bjørnholm, T

    2006-03-01

    Boron carbide nanoparticles are proposed as a system for T cell-guided boron neutron capture therapy. Nanoparticles were produced by ball milling in various atmospheres of commercially available boron carbide. The physical and chemical properties of the particles were investigated using transmission electron microscopy, photon correlation spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, vibrational spectroscopy, gel electrophoresis and chemical assays and reveal profound changes in surface chemistry and structural characteristics. In vitro thermal neutron irradiation of B16 melanoma cells incubated with sub-100 nm nanoparticles (381.5 microg/g (10)B) induces complete cell death. The nanoparticles alone induce no toxicity.

  6. Fabrication of boron nitride planar field emitters

    Science.gov (United States)

    Yokota, Yuuko; Tagawa, Shigeru; Sugino, Takashi

    1999-05-01

    Boron nitride (BN) films are grown on sapphire substrates by plasma-assisted chemical vapor deposition (PACVD). BN films are doped with sulfur. Insertion of the GaN layer between the BN film and sapphire leads to a tight adhesion of the BN film. The electrical resistivity of the sulfur-doped BN film is reduced to 10 3 Ω cm. The cathode electrode is formed on the BN film and the anode electrode on the sapphire substrate by evaporating Ti and Au. An emission current of 1 μA is obtained at an electric field strength of 16 V/μm.

  7. For boron neutron capture therapy,synthesizing boron-polymer compounds and testing in laboratory conditions

    International Nuclear Information System (INIS)

    2011-01-01

    The aim of this project is to establish a focus point at Turkish Atomic Energy Authority (TAEA) in the field of Boron Neutron Capture Therapy which is a binary radiotherapy method for brain tumours. Moreover in the scope of the project, a new alternative of 1 0B-carrier compounds will be synthesized, the neutron source will be determined and the infrastructure to start the clinical trials of BNCT in our country will be established. BNCT is a binary radiotherapy method and the successful of this method is depend on the synthesized boron compounds which have the selective targeting property with tumour cells and neutron optimization. The water-soluble polymer based boron compounds having biochemical and physiological properties will be synthesized and cell culture experiment will be done. In addition, after the neutron source is set up in our country, the infrastructure studies will be started in order to start the clinical trials of BNCT. In this project, there are three different groups as boron compounds, neutron physics and medical group. Neutron physics group is starting the calculations of neutron beam parameters using in BNCT application. But, medical group has no active studies yet. Boron compounds group has been carried out two different experimental studies. In the first experimental study, functional groups have been bound to boron containing polymers to enhance the selectively targeting property and characterized by various analysis methods. Later, cell culture experiment will be done. The first study has been carried out with Hacettepe University. Up to present, completed studies are listed as: -Maleic anhydride oligomer was synthesized and then 2-aminoethyl diphenyl borate (2-AEPB) and monomethoxy poly(ethylene glycol) (PEG) was bound to this oligomer, respectively. Thus, [MAH] n -g 1 -2-AEPB-g 2 -PEG was synthesized. -2-AEPB compound were bound to poly(acrylic acid) polymer at different three mole ratio.Then, the selected Poli(Ac)-g 1 -2-AEPB polymer

  8. Electron transport in HBr adsorbed boron doped carbon nanotube

    Science.gov (United States)

    Srivastava, Reena; Shahzad Khan, Md.; Shrivastava, Sadhna; Srivastava, Anurag

    2017-01-01

    A 10,0 pristine as well as boron doped zigzag single walled carbon nanotube has been analyzed as possible HBr sensor using DFT based ab-initio approach. The variation in band structures, Mulliken charge, NBO charge, binding energy and conductance variation has been analyzed. The CNT observes a lowering of bandgap in presence of HBr molecule near its surface and reduces the metallicity of Boron doped CNT. The B-CNT shows semiconducting to metallic transition and on introducing the HBr molecule near the surface, changes its conductance drastically. Strong physisorption is observed for HBr over B-CNT surface as a consequence of electrostatic interaction.

  9. Neutron-gamma discrimination of boron loaded plastic scintillator

    International Nuclear Information System (INIS)

    Wang Dong; He Bin; Zhang Quanhu; Wu Chuangxin; Luo Zhonghui

    2010-01-01

    Boron loaded plastic scintillator could detect both fast neutrons thanks to hydrogen and thermal neutrons thanks to 10B. Both reactions have large cross sections, and results in high detection efficiency of incident neutrons. However, similar with other organic scintillators, boron loaded plastic scintillator is sensitive to gamma rays and neutrons. So gamma rays must be rejected from neutrons using their different behavior in the scintillator. In the present research zero crossing method was used to test neutron-gamma discrimination of BC454 boron loaded plastic scintillator. There are three Gaussian peaks in the time spectrum, they are corresponding to gamma rays, fast neutrons and flow neutrons respectively. Conclusion could be made that BC454 could clear discriminate slow neutrons and gamma, but the discrimination performance turns poor as the neutrons' energy becomes larger. (authors)

  10. miR-224 promotion of cell migration and invasion by targeting Homeobox D 10 gene in human hepatocellular carcinoma.

    Science.gov (United States)

    Li, Qiong; Ding, Chenchen; Chen, Chuan; Zhang, Zhimin; Xiao, He; Xie, Fei; Lei, Lin; Chen, Yuanyuan; Mao, Bijing; Jiang, Mei; Li, Jian; Wang, Dong; Wang, Ge

    2014-04-01

    MicroRNAs (miRNAs) are small noncoding RNA molecules that control target gene expression and are implicated in the regulation of diverse cellular pathways. In our previous research, we have demonstrated that miR-224 was overexpressed in liver cancer cells and tissues, which was an important factor in the regulation of cell migration and invasion. This study aimed to further explore the regulatory mechanism of miR-224 in the migration and invasion in liver cancer cells. A luciferase reporter assay was used to confirm that the HOXD10 gene was a direct target of miR-224. Quantitative reverse transcriptase-polymerase chain reaction, Western blotting, Transwell migration, and Matrigel invasion assays were performed to clarify the molecular mechanism of miR-224 in the regulation of cell migration and invasion in human hepatocellular carcinoma (HCC). (i) The expression of miR-224 was strongly upregulated in MHHC97H and MHCC97L cells, and its expression level was significantly associated with cell invasive potential. (ii) The HOXD10 gene was confirmed to be a direct target of miR-224. Compared with normal liver tissues and cells, HOXD10 had lower expression in HCC tissues and cells and inversely regulated HCC cell invasion. (iii) miR-224 promoted expression of the tumor invasion-associated proteins p-PAK4 and MMP-9 by directly targeting HOXD10. Our findings suggest a previously undescribed regulatory pathway in which the miR-224/HOXD10/p-PAK4/MMP-9 signaling pathway contributes to the regulation of cell migration and invasion and provides a new biotarget for HCC treatment. © 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

  11. Considerations for boron neutron capture therapy studies; Consideracoes sobre o estudo da BNCT (terapia de captura neutronica por boro)

    Energy Technology Data Exchange (ETDEWEB)

    Faria Gaspar, P. de

    1994-12-31

    Radiotherapy is indispensable as a mean to eradicate deeply or infiltrating tumor tissue that can not be removed surgically. Therefore, it is not selective and may also kill the surrounding health tissue. The principle of BNCT (Boron Neutron Capture Therapy) consist in targeting a tumor selectively with a boron-10 compound. This nuclide has a large capture cross section for thermal neutrons and the nuclear reaction and the delivered energy in locus will selective the tumor. Since its initial proposal in 1963 BNCT has made much progress, however it is not used in a routine treatment. In this work it was approached some complex procedures, as the obtention of selective boron compounds, the adequate set up of neutron beams, the biodistribution, the in vivo and in vitro studies, and also human patients treatments. This work provide fundamentals about BNCT to professional of different areas of knowledge since it comprises multidisciplinary study. It includes appendixes for the ones not related to the field for a better comprehension of the many aspects involved. It is also presented a glossary containing technical and basic aspects involved. It is also presented a glossary containing technical and basic terms referred in the work. (author). 174 refs, 1 fig, 12 apps.

  12. Future boronated molecules for neutron capture therapy

    International Nuclear Information System (INIS)

    Soloway, A.H.; Alam, F.; Barth, R.F.

    1986-01-01

    The ability of several boron compounds to localize in tumor cells is examined. A number of first and second generation compounds which were not synthesized specifically for localization are described. Among these are the boron hydrides and boranes. A third generation of boron compounds are designed for selective localization. These fall into two groups: relatively small organic compounds and boronated antibodies, both of which are discussed here

  13. Compression and Associated Properties of Boron Carbide

    Science.gov (United States)

    2008-12-01

    Klandadze, G.I., and Eristavi, A.M., 1999: IR- Active Phonons and Structure Elements of Isotope - Enriched Boron Carbide, J. Sol. State Chem. 154, 79- 86...COMPRESSION AND ASSOCIATED PROPERTIES OF BORON CARBIDE D. P. Dandekar*and J. A. Ciezak Army Research Laboratory, APG, MD 21005 M. Somayazulu...of the observed loss of shear strength in boron carbide under plane shock wave compression to amorphization in boron carbide under triaxial stress

  14. Lattice vibrations in α-boron

    International Nuclear Information System (INIS)

    Richter, W.

    1976-01-01

    α-rhombohedral boron is the simplest boron modification, with only 12 atoms per unit cell. The boron atoms are arranged in B 12 icosahedra, which are centered at the lattice points of a primitive rhombohedral lattice. The icosahedra are slightly deformed, as the five-fold symmetry of the ideal icosahedron is incompatible with any crystal structure. The lattice dynamics of α-boron are discussed in terms of the model developed by Weber and Thorpe. (Auth.)

  15. Synthesis of oligomeric boron-containing phospolyols

    International Nuclear Information System (INIS)

    Bondarenko, S.N.; Khokhlova, T.V.; Orlova, S.A.; Tuzhikov, O.I.

    2006-01-01

    Structure is investigated and reactivity of oligomeric boron-containing phospolyols is studied. Oligomeric boron-containing compound interacts with ethylene glycol, diethylene glycol, glycerol, 1,4-butandiol with formation of linear boron-containing phospolyols. Reactions proceed in noncatalytic conditions with stoichiometric quantities of reagents at 170-200 Deg C in inert gas media. Boron-containing phospolyols are viscous uncolored liquids, their physicochemical characteristics are represented [ru

  16. Antioxidant responses of lentil and barley plants to boron toxicity ...

    African Journals Online (AJOL)

    Administrator

    2Muammer Tepe; High Biochemist, Celal Bayar University Science and Arts Faculty, Turkey. Accepted 2 June, 2011. In this study, the effects of different nitrogen ... for 7-day growth cycle under the conditions of boron stress via different nitrogen sources (10 mM nitrogen in NH4 Cl, KNO3 and urea). As a result of the changes ...

  17. Functionalization and cellular uptake of boron carbide nanoparticles

    DEFF Research Database (Denmark)

    Mortensen, M. W.; Björkdahl, O.; Sørensen, P. G.

    2006-01-01

    In this paper we present surface modification strategies of boron carbide nanoparticles, which allow for bioconjugation of the transacting transcriptional activator (TAT) peptide and fluorescent dyes. Coated nanoparticles can be translocated into murine EL4 thymoma cells and B16 F10 malignant...

  18. A theranostic approach based on the use of a dual boron/Gd agent to improve the efficacy of Boron Neutron Capture Therapy in the lung cancer treatment.

    Science.gov (United States)

    Alberti, Diego; Protti, Nicoletta; Toppino, Antonio; Deagostino, Annamaria; Lanzardo, Stefania; Bortolussi, Silva; Altieri, Saverio; Voena, Claudia; Chiarle, Roberto; Geninatti Crich, Simonetta; Aime, Silvio

    2015-04-01

    This study aims at developing an innovative theranostic approach for lung tumor and metastases treatment, based on Boron Neutron Capture Therapy (BNCT). It relies on to the use of low density lipoproteins (LDL) as carriers able to maximize the selective uptake of boron atoms in tumor cells and, at the same time, to quantify the in vivo boron distribution by magnetic resonance imaging (MRI). Tumor cells uptake was initially assessed by ICP-MS and MRI on four types of tumor (TUBO, B16-F10, MCF-7, A549) and one healthy (N-MUG) cell lines. Lung metastases were generated by intravenous injection of a Her2+ breast cancer cell line (i.e. TUBO) in BALB/c mice and transgenic EML4-ALK mice were used as primary tumor model. After neutron irradiation, tumor growth was followed for 30-40 days by MRI. Tumor masses of boron treated mice increased markedly slowly than the control group. From the clinical editor: In this article, the authors described an improvement to existing boron neutron capture therapy. The dual MRI/BNCT agent, carried by LDLs, was able to maximize the selective uptake of boron in tumor cells, and, at the same time, quantify boron distribution in tumor and in other tissues using MRI. Subsequent in vitro and in vivo experiments showed tumor cell killing after neutron irradiation. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. BORON-NITROGEN RELATIONSHIP IN WHEAT (Triticum aestivum L.) GROWN WITH THE NUTRIENT SOLUTION

    OpenAIRE

    Mehmet ALPASLAN; Süleyman TABAN; Ali İNAL; A. Cihat KÜTÜK; İbrahim ERDAL

    1996-01-01

    The effects of boron applied 0.01, 0.1, 1.0, and 10.0 µg B/ml levels as boric acid (H3 BO3), and nitrogen applied 25, 100, 200, and 400 µg N/ml as ammonium nitrate (NH4 NO3), respectively, on the amount of dry matter yield, and boron, nitrogen and nitrate contents of wheat (Triticum aestivum L.) grown in perlite medium with Ruakura nutrient solution under greenhouse conditions were investigated. Dry matter yield and nitrate contents of wheat were decreased and boron content was increased with...

  20. Shock experiments in range of 10–45 GPa with small multidomain magnetite in porous targets

    Czech Academy of Sciences Publication Activity Database

    Kohout, Tomáš; Pesonen, L. J.; Deutsch, A.; Wünnemann, K.; Nowka, D.; Hornemann, U.; Heikinheimo, E.

    2012-01-01

    Roč. 47, č. 10 (2012), s. 1671-1680 ISSN 1086-9379 Institutional research plan: CEZ:AV0Z30130516 Keywords : shock * magnetite * magnetism * magnetic properties * density porosity Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 2.800, year: 2012

  1. Determination of boron in water solution by an indirect neutron activation technique from a 241Am/Be source

    International Nuclear Information System (INIS)

    Sales, H.B.

    1981-08-01

    Boron content in water solutions has been analysed by Indirect Activation Technique a twin 241 Am/Be neutron source with a source strength of 9x10 6 n/seg. The boron concentration was inferred from the measurement of the activity induced in a vanadium flux monitor. The vanadium rod was located inside the boron solution in a standart geometrical set up with respect to the neutron source. Boron concentrations in the range of 100 to 1000 ppm were determined with an overall accuracy of about 2% during a total analysis time of about 20 minutes. Eventhough the analysis is not selective for boron yet due the rapid, simple and precise nature, it is proposed for the analysis of boron in the primary coolant circuit of Nuclear Power Plants of PWR type. (Author) [pt

  2. Ground Target Modeling and Validation Conference (10th) Held in Houghton, Michigan, on 17-19 August 1999

    Science.gov (United States)

    1999-08-01

    Facet Files Combined Into a Single Vehicle File \\m «>IB .piu own am [.»- Figure 10. The converted vehicle facet file displayed in Xpatch’s...reflected from single plates: each has different area Am , orientation and surface reflectance chararcteristics. This reflectance is completely described...significant variation in overall scene luminance and contrast trasmittance . 3. Most of the vehicles were easy to detect. Only 3 of the 44 targets had

  3. Structures, stability, mechanical and electronic properties of a-boron and its twined brother a*-boron

    OpenAIRE

    He, Chaoyu; Zhong, Jianxin

    2013-01-01

    The structures, stability, mechanical and electronic properties of a-boron and its twined brother a*-boron have been studied by first-principles calculations. Both a-boron and a*-boron consist of equivalent icosahedra B12 clusters in different connecting configurations of "3S-6D-3S" and "2S-6D-4S", respectively. The total energy calculations show that a*-boron is less stable than a-boron but more favorable than beta-boron and Gamma-boron at zero pressure. Both a-boron and a*-boron are confirm...

  4. Scotoma analysis of 10–2 visual field testing with a red target in screening for hydroxychloroquine retinopathy

    Directory of Open Access Journals (Sweden)

    Browning DJ

    2015-08-01

    Full Text Available David J Browning, Chong LeeDepartment of Ophthalmology, Charlotte Eye, Ear, Nose and Throat Associates, Charlotte, NC, USAObjective: To quantify the variability of scotomas detected by 10–2 visual field (VF testing with a red target in patients taking hydroxychloroquine without and with retinopathy.Design: Retrospective review of clinical charts and VFs.Methods: Twenty-four patients taking hydroxychloroquine without retinopathy, and eight patients taking hydroxychloroquine with retinopathy were tested in this study. Retinopathy was defined by annular scotomas on 10–2 VF testing with corroborative spectral domain optical coherence tomographic outer retinal changes and multifocal electroretinographic changes leading to cessation of hydroxychloroquine or chloroquine. Location and depth of scotoma points on 10–2 VF testing were recorded and their fates followed in serial, reliable 10–2 VFs performed with a red target over time. The main outcome measures for this study were the number of scotoma points and locations, percentage of persistent scotoma points, size of scotomas, location of scotomas, and percentage of scotomas deepening. Results: A median of 3, interquartile range (IQR (2, 5, scotoma points per VF occurred in patients without retinopathy. A median of 86%, IQR (77, 100, of these resolved on the subsequent field. For patients with retinopathy, a median of 50%, IQR (46, 79, resolved, a difference compared to patients without retinopathy that was significant (P=0.0158. The median percentage of scotoma points in the zone from 2° to 8° from fixation in eyes with retinopathy was 72%, IQR (54, 100, compared to 49%, IQR (40, 54, in eyes without retinopathy (P=0.0069. The number of persistent scotoma locations at the last visit was higher in eyes with retinopathy: 3, IQR (1, 3, versus 0, IQR (0, 1, in patients without retinopathy, P=0.0156.Conclusion: Point scotomas are common and variable in 10–2 VF testing with a red target for

  5. Targeting PDE10A GAF Domain with Small Molecules: A Way for Allosteric Modulation with Anti-Inflammatory Effects.

    Science.gov (United States)

    García, Ana M; Brea, José; González-García, Alejandro; Pérez, Concepción; Cadavid, María Isabel; Loza, María Isabel; Martinez, Ana; Gil, Carmen

    2017-09-04

    Phosphodiesterase (PDE) enzymes regulate the levels of cyclic nucleotides, cAMP, and/or cGMP, being attractive therapeutic targets. In order to modulate PDE activity in a selective way, we focused our efforts on the search of allosteric modulators. Based on the crystal structure of the PDE10A GAF-B domain, a virtual screening study allowed the discovery of new hits that were also tested experimentally, showing inhibitory activities in the micromolar range. Moreover, these new PDE10A inhibitors were able to decrease the nitrite production in LPS-stimulated cells, thus demonstrating their potential as anti-inflammatory agents.

  6. Fixing tools of targets for radioisotope production in the RA10

    International Nuclear Information System (INIS)

    Peirone, M.; Coleff, A.; Chasseur, A.

    2012-01-01

    The RA-10 project is about the design and construction of a reactor for radioisotopes production and scientific research in the nuclear area. Most of the reactor design comes from INVAP SE, however some of the design job was performed in CNEA, i.e. the so called Outer Core Experimental Devices (DEEN) and their interfaces with the Reflector Tank were designed in CNEA and the documentation of the basic design was recently released (author)

  7. Synthesis and mechanical properties of boron suboxide thin films

    International Nuclear Information System (INIS)

    Music, Denis; Schneider, Jochen M.; Kugler, Veronika; Nakao, Setsuo; Jin, Ping; Oestblom, Mattias; Hultman, Lars; Helmersson, Ulf

    2002-01-01

    Boron suboxide thin films have been deposited on Si(100) and graphite substrates by reactive rf magnetron sputtering of a sintered B target in an Ar/O 2 atmosphere. X-ray photoelectron spectroscopy, elastic recoil detection analysis, Fourier transform infrared spectroscopy, x-ray diffraction, and transmission electron microscopy were applied to study the influence of the O 2 partial pressure on the film composition and microstructure. BO x thin films with x=[0.02-0.21] and a C impurity of approximately 0.3 at. % were formed by varying the O 2 partial pressure from 7.2x10 -7 to 3.3x10 -2 Pa. All films were amorphous and the films with x≥0.15 contained boric acid on the surface due to a probable chemical reaction with water in laboratory atmosphere. Mechanical properties were evaluated by nanoindentation. As x was increased from 0.02 to 0.21, the elastic modulus decreased from 272 to 109 GPa. The change in the elastic modulus was attributed to the O concentration variations

  8. Vitamin D Receptor Agonists Target CXCL10: New Therapeutic Tools for Resolution of Inflammation

    Directory of Open Access Journals (Sweden)

    Sabino Scolletta

    2013-01-01

    Full Text Available Understanding the many biological extraskeletal actions of vitamin D has increased in the past decades. Indeed, vitamin D and analogue molecules, besides the classical actions on bone metabolism, exert several beneficial effects on metabolic homeostasis, heart-cardiovascular, brain, and muscle physiological functions, throughout the interaction with the specific vitamin D receptor (VDR. In particular, VDR agonists powerfully control innate and adaptive immune system with favorable effects on human health. VDR ligands act as immunomodulators that are potent enough to retain anti-inflammatory effects, even though the mechanism underlying those effects is not yet fully elucidated. VDR agonists exert a significant suppression of inflammatory processes switching the immune response from T helper 1 (Th1 to T helper 2 (Th2 dominance and counteracting the self-enhancing inflammatory loop between immune and resident cells, especially by cytokine release impairment. Those molecules are able, indeed, to reduce the release of the interferon (IFN-induced 10 kDa protein IP-10/CXCL10, a powerful chemokine driving Th1-mediated inflammation. Based on their features, VDR ligands show the potentiality to be included in immunosuppressive regimens, aimed to control auto- and alloimmune Th1-driven overreactivity, occurring, for example, in autoimmune disease or graft rejection.

  9. Enzyme activity assay of glycoprotein enzymes based on a boronate affinity molecularly imprinted 96-well microplate.

    Science.gov (United States)

    Bi, Xiaodong; Liu, Zhen

    2014-12-16

    Enzyme activity assay is an important method in clinical diagnostics. However, conventional enzyme activity assay suffers from apparent interference from the sample matrix. Herein, we present a new format of enzyme activity assay that can effectively eliminate the effects of the sample matrix. The key is a 96-well microplate modified with molecularly imprinted polymer (MIP) prepared according to a newly proposed method called boronate affinity-based oriented surface imprinting. Alkaline phosphatase (ALP), a glycoprotein enzyme that has been routinely used as an indicator for several diseases in clinical tests, was taken as a representative target enzyme. The prepared MIP exhibited strong affinity toward the template enzyme (with a dissociation constant of 10(-10) M) as well as superb tolerance for interference. Thus, the enzyme molecules in a complicated sample matrix could be specifically captured and cleaned up for enzyme activity assay, which eliminated the interference from the sample matrix. On the other hand, because the boronate affinity MIP could well retain the enzymatic activity of glycoprotein enzymes, the enzyme captured by the MIP was directly used for activity assay. Thus, additional assay time and possible enzyme or activity loss due to an enzyme release step required by other methods were avoided. Assay of ALP in human serum was successfully demonstrated, suggesting a promising prospect of the proposed method in real-world applications.

  10. Proceedings of workshop on 'boron chemistry and boron neutron capture therapy'

    International Nuclear Information System (INIS)

    Kitaoka, Yoshinori

    1993-09-01

    This volume contains the proceedings of the 5th Workshop on 'the Boron Chemistry and Boron Neutron Capture Therapy' held on February 22 in 1993. The solubility of the boron carrier play an important role in the BNCT. New water-soluble p-boronophenylalanine derivatives are synthesized and their biological activities are investigated (Chap. 2 and 3). Some chemical problems on the BNCT were discussed, and the complex formation reaction of hydroxylboryl compounds were studied by the paper electrophoresis (Chap. 4). The results of the medical investigation on the BNCT using BSH compounds are shown in Chap. 5. Syntheses of o- and m-boronophenylalanine were done and their optical resolution was tried (Chap. 6). The complex formation reaction of p-boronophenylalanine (BPA) with L-DOPA and the oxidation reaction of the analogs are found in Chap. 7. The pka of BPA were determined by the isotachophoresis (Chap. 8). The chemical nature of dihydroxyboryl compounds were investigated by an infrared spectroscopy and electrophoresis (Chap. 9). New synthetic methods of BPA and p-boronophenylserine using ester of isocyanoacetic acid are described in Chap. 10. The induction of chromosomal aberations by neutron capture reaction are discussed from a point of the biological view. The a of the presented papers are indexed individually. (J.P.N.)

  11. Boron isotope separation by ion exchange chromatography using weakly basic anion exchange resin

    International Nuclear Information System (INIS)

    Sakuma, Yoichi; Aida, Masao; Okamoto, Makoto; Kakihana, Hidetake

    1980-01-01

    Isotopic plateau displacement chromatography, a useful method for isotope separation is presented. The boric acid band formed in a column of weakly basic anion exchange resin Diaion WA21 can be eluted with pure water. In order to obtain good accumulation of the isotope effect, a series of experiments with different migration length were carried out. The boron-10 enriched part of the boric acid absorbed band was always preceded by the isotopic plateau part, in which the atomic fraction of boron-10 was maintained at its original value. The atomic fraction of boron-10 at the end of the chromatogram increased with migration length, and in the case of 256-m migration, boron-10 was enriched from its original atomic fraction of 19.84 to 91.00%, the separation factor S being constant irrespective of migration length: S = 1.0100 +- 0.0005. (author)

  12. Genotypic effects on boron concentrations and response on boron fertilization in maize inbred lines

    Directory of Open Access Journals (Sweden)

    Andrić Luka

    2016-01-01

    Full Text Available Boron (B deficiency in maize can result in barren cobs attributed to silks being nonreceptive which is particularly important for the female parent in seed production. The objectives of this study were 1 to investigate genotypic differences among nine female inbred lines used in seed production for B concentration in ear-leaf and grain, as well as for grain yield and moisture in a three-year experiment (2006-2008 and 2 to determine response and relations among the traits when four of the female inbred lines are treated by foliar boron fertilization - three times in 10-days interval with 0.5% Solubor solution (17.5% B during one growing season (2008. The investigations were performed on Experimental field of Agricultural Institute Osijek, (soil type: eutrical cambisol. Highly significant differences among the nine female inbred lines were detected for B concentration in ear-leaf (from 14.7 to 46.7 mg B kg-1 and grain (from 1.20 to 2.06 mg B kg-1 as well as for grain yield (from 3.33 to 4.83 t ha-1 and grain moisture (from 14.7% to 26.6%. However, there were also significant effects of growing season and the genotype by environment interaction for all four traits. Positive and moderate correlations were found between the boron status in plant and grain yield. Although B concentrations were considerably increased by foliar boron fertilization (averages 41.7 and 125.3 mg B kg-1 in leaves, 1.79 and 2.80 mg B kg-1 in grain, for control and fertilization, respectively, in general grain yield differences among treatments were non-significant. (averages 5.21 and 5.15 t ha-1, respectively.

  13. Boron steel. I Part. Preparation

    International Nuclear Information System (INIS)

    Jaraiz Franco, E.; Esteban Hernandez, J. A.

    1960-01-01

    With the advent of the first nuclear reactors arise the need for control rods and shielding duties for some types of radiations. One of the materials used for this purpose has been the high boron steel. This paper describes the melting and casting procedures employed for the production, at laboratory scale, of steels with Boron content ranging from 1 to 4 per cent, as well as the metallographic and X-Ray techniques used for the identification of the present phases. The electrolytic technique employed for the isolation of the Fe 2 B phase and its subsequent X-Ray identification has proved to be satisfactory. (Author) 11 refs

  14. Thermal conductivity of boron carbides

    Science.gov (United States)

    Wood, C.; Emin, D.; Gray, P. E.

    1985-01-01

    Knowledge of the thermal conductivity of boron carbide is necessary to evaluate its potential for high-temperature thermoelectric energy conversion applications. Measurements have been conducted of the thermal diffusivity of hot-pressed boron carbide BxC samples as a function of composition (x in the range from 4 to 9), temperature (300-1700 K), and temperature cycling. These data, in concert with density and specific-heat data, yield the thermal conductivities of these materials. The results are discussed in terms of a structural model that has been previously advanced to explain the electronic transport data. Some novel mechanisms for thermal conduction are briefly discussed.

  15. New Icosahedral Boron Carbide Semiconductors

    Science.gov (United States)

    Echeverria Mora, Elena Maria

    Novel semiconductor boron carbide films and boron carbide films doped with aromatic compounds have been investigated and characterized. Most of these semiconductors were formed by plasma enhanced chemical vapor deposition. The aromatic compound additives used, in this thesis, were pyridine (Py), aniline, and diaminobenzene (DAB). As one of the key parameters for semiconducting device functionality is the metal contact and, therefore, the chemical interactions or band bending that may occur at the metal/semiconductor interface, X-ray photoemission spectroscopy has been used to investigate the interaction of gold (Au) with these novel boron carbide-based semiconductors. Both n- and p-type films have been tested and pure boron carbide devices are compared to those containing aromatic compounds. The results show that boron carbide seems to behave differently from other semiconductors, opening a way for new analysis and approaches in device's functionality. By studying the electrical and optical properties of these films, it has been found that samples containing the aromatic compound exhibit an improvement in the electron-hole separation and charge extraction, as well as a decrease in the band gap. The hole carrier lifetimes for each sample were extracted from the capacitance-voltage, C(V), and current-voltage, I(V), curves. Additionally, devices, with boron carbide with the addition of pyridine, exhibited better collection of neutron capture generated pulses at ZERO applied bias, compared to the pure boron carbide samples. This is consistent with the longer carrier lifetimes estimated for these films. The I-V curves, as a function of external magnetic field, of the pure boron carbide films and films containing DAB demonstrate that significant room temperature negative magneto-resistance (> 100% for pure samples, and > 50% for samples containing DAB) is possible in the resulting dielectric thin films. Inclusion of DAB is not essential for significant negative magneto

  16. Chemical separation of boron isotopes

    International Nuclear Information System (INIS)

    Palko, A.A.

    1978-06-01

    This is the final report of the research performed at ORNL on the chemical fractionation of boron isotopes between BF 3 gas and the liquid molecular addition compounds of BF 3 . Thirty compounds were studied, ten of them in detail. Graphs and equations are given for variation of isotopic equilibrium constant, vapor pressure, and BF 3 solubility as a function of temperature. Rate of isotopic exchange and melting points were determined. Several of the compounds are likely candidates for use in a gas-liquid countercurrent exchange system for large-scale separation of boron isotopes. 23 figs, 53 tables, 39 references

  17. Chemical separation of boron isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Palko, A.A.

    1978-06-01

    This is the final report of the research performed at ORNL on the chemical fractionation of boron isotopes between BF/sub 3/ gas and the liquid molecular addition compounds of BF/sub 3/. Thirty compounds were studied, ten of them in detail. Graphs and equations are given for variation of isotopic equilibrium constant, vapor pressure, and BF/sub 3/ solubility as a function of temperature. Rate of isotopic exchange and melting points were determined. Several of the compounds are likely candidates for use in a gas-liquid countercurrent exchange system for large-scale separation of boron isotopes. 23 figs, 53 tables, 39 references.

  18. Boron cycling in subduction zones

    OpenAIRE

    Palmer, Martin R.

    2017-01-01

    Subduction zones are geologically dramatic features, with much of the drama being driven by the movement of water. The “light and lively” nature of boron, coupled with its wide variations in isotopic composition shown by the different geo-players in this drama, make it an ideal tracer for the role and movement of water during subduction. The utility of boron ranges from monitoring how the fluids that are expelled from the accretionary prism influence seawater chemistry, to the subduction of c...

  19. Boronic acids facilitate rapid oxime condensations at neutral pH† †Dedicated to Andreas Pfaltz on the occasion of his retirement. ‡ ‡Electronic supplementary information (ESI) available: Detailed kinetic data, HPLC assays, and characterization data for all new compounds are provided. See DOI: 10.1039/c5sc00921a Click here for additional data file.

    Science.gov (United States)

    Schmidt, Pascal; Stress, Cedric

    2015-01-01

    We report here the discovery and development of boron-assisted oxime formation as a powerful connective reaction for chemical biology. Oximes proximal to boronic acids form in neutral aqueous buffer with rate constants of more than 104 M–1 s–1, the largest to date for any oxime condensation. Boron's dynamic coordination chemistry confers an adaptability that seems to aid a number of elementary steps in the oxime condensation. In addition to applications in bioconjugation, the emerging importance of boronic acids in chemical biology as carbohydrate receptors or peroxide probes, and the growing list of drugs and drug candidates containing boronic acids suggest many potential applications. PMID:29142692

  20. Alleviation of Boron Stress through Plant Derived Smoke Extracts in Sorghum bicolor

    Directory of Open Access Journals (Sweden)

    Pirzada Khan

    2014-08-01

    Full Text Available Boron is an essential micronutrient necessary for plant growth at optimum concentration. However, at high concentrations boron affects plant growth and is toxic to cells. Aqueous extract of plant-derived smoke has been used as a growth regulator for the last two decades to improve seed germination and seedling vigor. It has been established that plant-derived smoke possesses some compounds that act like plant growth hormones. The present research was the first comprehensive attempt to investigate the alleviation of boron stress with plant-derived smoke aqueous extract on Sorghum (Sorghum bicolor seed. Smoke extracts of five plants, i.e. Cymbopogon jwarancusa, Eucalyptus camaldulensis, Peganum harmala, Datura alba and Melia azedarach each with six dilutions (Concentrated, 1:100, 1:200, 1:300, 1:400 and 1:500 were used. While boron solutions at concentrations of 5, 10, 15, 20 and 25 ppm were used for stress. Among the dilutions of smoke, 1:500 of E. camaldulensis significantly increased germination percentage, root and shoot length, number of secondary roots and fresh weight of root and shoot while, boron stress reduced growth of Sorghum. It was observed that combined effect of boron solution and E. camaldulensis smoke extract overcome inhibition and significantly improved plant growth. Present research work investigated that the smoke solution has the potential to alleviate boron toxicity by reducing the uptake of boron by maintaining integrity of plant cell wall. The present investigation suggested that plant derived smoke has the potential to alleviate boron stress and can be used to overcome yield losses caused by boron stress to plants.

  1. Boron Nitride Nanoribbons from Exfoliation of Boron Nitride Nanotubes

    Science.gov (United States)

    Hung, Ching-Cheh; Hurst, Janet; Santiago, Diana

    2017-01-01

    Two types of boron nitride nanotubes (BNNTs) were exfoliated into boron nitride nanoribbons (BNNR), which were identified using transmission electron microscopy: (1) commercial BNNTs with thin tube walls and small diameters. Tube unzipping was indicated by a large decrease of the sample's surface area and volume for pores less than 2 nm in diameter. (2) BNNTs with large diameters and thick walls synthesized at NASA Glenn Research Center. Here, tube unraveling was indicated by a large increase in external surface area and pore volume. For both, the exfoliation process was similar to the previous reported method to exfoliate commercial hexagonal boron nitride (hBN): Mixtures of BNNT, FeCl3, and NaF (or KF) were sequentially treated in 250 to 350 C nitrogen for intercalation, 500 to 750 C air for exfoliation, and finally HCl for purification. Property changes of the nanosized boron nitride throughout this process were also similar to the previously observed changes of commercial hBN during the exfoliation process: Both crystal structure (x-ray diffraction data) and chemical properties (Fourier-transform infrared spectroscopy data) of the original reactant changed after intercalation and exfoliation, but most (not all) of these changes revert back to those of the reactant once the final, purified products are obtained.

  2. Synthesis of boron nitride from boron containing poly (vinyl alcohol ...

    Indian Academy of Sciences (India)

    A ceramic precursor, prepared by condensation reaction from poly(vinyl alcohol) (PVA) and boric acid (H3BO3) in 1:1, 2:1 and 4:1 molar ratios, was synthesized as low temperature synthesis route for boron nitride ceramic. Samples were pyrolyzed at 850°C in nitrogen atmosphere followed by characterization using Fourier ...

  3. Boron-Containing Compounds for Liposome-Mediated Tumor Localization and Application to Neutron Capture Therapy

    International Nuclear Information System (INIS)

    Hawthorne, M. Frederick

    2005-01-01

    Medical application of boron neutron capture therapy (BNCT) has been significantly hindered by the slow development of boron drug-targeting methodologies for the selective delivery of high boron concentration sto malignant cells. We have successfully sought to fill this need by creating liposomes suitable as in vivo boron delivery vehicles for BNCT. Delivery of therapeutic quantities of boron to tumors in murine models has been achieved with small unilamellar boron-rich liposomes. Subsequently, attempts have been made to improve delivery efficiency of liposomes encapsulating boron-containing water-soluble species into their hollow core by incorporating lipophilic boron compounds as addenda to the liposome bilayer, incorporating boron compounds as structural components of the bilayer (which however, poses the risk of sacrificing some stability), and combinations thereof. Regardless of the method, approximately 90% of the total liposome mass remains therapeutically inactive and comprised of the vehicle's construction materials, while less than 5% is boron for neutron targeting. Following this laboratory's intensive study, the observed tumor specificity of certain liposomes has been attributed to their diminutive size of these liposomes (30-150 nm), which enables these small vesicles to pass through the porous, immature vasculature of rapidly growing tumor tissue. We surmised that any amphiphilic nanoparticle of suitable size could possess some tumor selectivity. Consequently, the discovery of a very boron-rich nanoparticle delivery agent with biodistribution performance similar to unilamellar liposomes became one of our goals. Closomers, a new class of polyhedral borane derivatives, attracted us as an alternative BNCT drug-delivery system. We specifically envisioned dodeca (nido-carboranyl)-substituted closomers as possibly having a great potential role in BNCT drug delivery. They could function as extraordinarily boron-rich BNCT drugs since they are amphiphilic

  4. Boron-Containing Compounds for Liposome-Mediated Tumor Localization and Application to Neutron Capture Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Hawthorne, M. Frederick [Univ. of California, Los Angeles, CA (United States)

    2005-04-07

    Medical application of boron neutron capture therapy (BNCT) has been significantly hindered by the slow development of boron drug-targeting methodologies for the selective delivery of high boron concentration sto malignant cells. We have successfully sought to fill this need by creating liposomes suitable as in vivo boron delivery vehicles for BNCT. Delivery of therapeutic quantities of boron to tumors in murine models has been achieved with small unilamellar boron-rich liposomes. Subsequently, attempts have been made to improve delivery efficiency of liposomes encapsulating boron-containing water-soluble species into their hollow core by incorporating lipophilic boron compounds as addenda to the liposome bilayer, incorporating boron compounds as structural components of the bilayer (which however, poses the risk of sacrificing some stability), and combinations thereof. Regardless of the method, approximately 90% of the total liposome mass remains therapeutically inactive and comprised of the vehicle's construction materials, while less than 5% is boron for neutron targeting. Following this laboratory's intensive study, the observed tumor specificity of certain liposomes has been attributed to their diminutive size of these liposomes (30-150 nm), which enables these small vesicles to pass through the porous, immature vasculature of rapidly growing tumor tissue. We surmised that any amphiphilic nanoparticle of suitable size could possess some tumor selectivity. Consequently, the discovery of a very boron-rich nanoparticle delivery agent with biodistribution performance similar to unilamellar liposomes became one of our goals. Closomers, a new class of polyhedral borane derivatives, attracted us as an alternative BNCT drug-delivery system. We specifically envisioned dodeca (nido-carboranyl)-substituted closomers as possibly having a great potential role in BNCT drug delivery. They could function as extraordinarily boron-rich BNCT drugs since they are

  5. Determination of boron spectrophotometry in thorium sulfate

    International Nuclear Information System (INIS)

    Federgrun, L.; Abrao, A.

    1976-01-01

    A procedure for the determination of microquantities of boron in nuclear grade thorium sulfate is described. The method is based on the extraction of BF - 4 ion associated to monomethylthionine (MMT) in 1,2 - dichloroethane. The extraction of the colored BF - 4 -MMT complex does not allow the presence of sulfuric and phosphoric acids; other anions interfere seriously. This fact makes the dissolution of the thorium sulfate impracticable, since it is insoluble in both acids. On the other hand, the quantitative separation of thorium is mandatory, to avoid the precipitation of ThF 4 . To overcome this difficulty, the thorium sulfate is dissolved using a strong cationic ion exchanger, Th 4+ being totally retained into the resin. Boron is then analysed in the effluent. The procedure allows the determination of 0.2 to 10.0 microgramas of B, with a maximum error of 10%. Thorium sulfate samples with contents of 0.2 to 2.0μg B/gTh have being analysed [pt

  6. Analytical boron diffusivity model in silicon for thermal diffusion from boron silicate glass film

    Science.gov (United States)

    Kurachi, Ikuo; Yoshioka, Kentaro

    2015-09-01

    An analytical boron diffusivity model in silicon for thermal diffusion from a boron silicate glass (BSG) film has been proposed in terms of enhanced diffusion due to boron-silicon interstitial pair formation. The silicon interstitial generation is considered to be a result of the silicon kick-out mechanism by the diffused boron at the surface. The additional silicon interstitial generation in the bulk silicon is considered to be the dissociation of the diffused pairs. The former one causes the surface boron concentration dependent diffusion. The latter one causes the local boron concentration dependent diffusion. The calculated boron profiles based on the diffusivity model are confirmed to agree with the actual diffusion profiles measured by secondary ion mass spectroscopy (SIMS) for a wide range of the BSG boron concentration. This analytical diffusivity model is a helpful tool for p+ boron diffusion process optimization of n-type solar cell manufacturing.

  7. PM10 speciation and determination of air quality target levels. A case study in a highly industrialized area of Spain.

    Science.gov (United States)

    Minguillón, M C; Querol, X; Alastuey, A; Monfort, E; Mantilla, E; Sanz, M J; Sanz, F; Roig, A; Renau, A; Felis, C; Miró, J V; Artíñano, B

    2007-01-01

    The paper shows how PM speciation studies allow the evaluation of the strategies to be followed to diminish PM pollution in highly industrialized areas with a large number of potential pollution sources. Evolution of levels and speciation of PM10 in the ceramic producing area of Castelló (East Spain) was studied from April 2002 until December 2005. PM10 levels were measured at one rural (Borriana-rural), two suburban (Almassora and Onda) and three urban (Borriana-urban, L'Alcora and Vila-real) sites, all influenced by the ceramics industry. Average PM10 levels varied between 27 and 36 microg/m3 for the study period. Evaluation of 1996-2005 PM data from Onda shows a clear decrease of PM levels since the beginning of 2002. Summer peak levels and winter minima occurred at both rural and suburban sites, whereas urban sites had no clear seasonal trend, with high PM10 episodes being due variously to local, regional, and African dust intrusion events. PM10 chemical analysis at four of the sites showed the dominant constituent to be mineral matter, exceeding by 5-12 microg/m3 the usual ranges of annual mineral loadings in PM10 at comparable Spanish urban or regional background sites with no industrial influence. Given current PM10 loadings, we recommend a lowering target of 3-5 microg/m3 of the annual mean at the urban sites, which should be achievable given available emission abatement techniques.

  8. Boron removal from wastewater using adsorbents.

    Science.gov (United States)

    Kluczka, J; Trojanowska, J; Zolotajkin, M; Ciba, J; Turek, M; Dydo, P

    2007-01-01

    In the present study, boron adsorption on activated alumina and activated carbon impregnated with calcium chloride, tartaric acid and mannitol was investigated. The adsorbate in question was the wastewater from the chemical landfill in Tarnowskie Gory of 25-70 mg l(-1) boron content. The removal of boron from the above-described wastewater was examined in the static (batch) and dynamic (column) experiments. The static experiments were carried out to assess boron adsorption isotherms, based on which the most efficient adsorbent as well as the rough resin load was determined. On the basis of the dynamic experiment results, the boron adsorptive capacities of the examined resins were deduced. It was concluded that the use of the impregnants increased the ability of activated carbon to adsorb boron. Granulated activated carbon WG-12 impregnated with mannitol was found to be the most promising for the boron removal from wastewater of the Chemical Wastewater Plant in Tarnowskie Gory.

  9. Measurements of Increased Enthalpies of Adsorption for Boron-Doped Activated Carbons

    Science.gov (United States)

    Gillespie, Andrew; Beckner, Matthew; Chada, Nagaraju; Schaeperkoetter, Joseph; Singh, Anupam; Lee, Mark; Wexler, Carlos; Burress, Jacob; Pfeifer, Peter

    2013-03-01

    Boron-doping of activated carbons has been shown to increase the enthalpies of adsorption for hydrogen as compared to their respective undoped precursors (>10kJ/mol compared to ca. 5kJ/mol). This has brought significant interest to boron-doped carbons for their potential to improve hydrogen storage. Boron-doped activated carbons have been produced using a process involving the deposition of decaborane (B10H14) and high-temperature annealing resulting in boron contents up to 15%. In this talk, we will present a systematic study of the effect that boron content has on the samples' structure, hydrogen sorption, and surface chemistry. Measurements have shown a significant increase in the areal hydrogen excess adsorption and binding energy. Experimental enthalpies of adsorption will be presented for comparison to theoretical predictions. Additionally, samples have been characterized by thermal gravimetric analysis, gas chromatography-mass spectroscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. TGA and GC-MS results investigated the decomposition of the decaborane in the carbon. Boron-carbon bonds are shown in the FTIR and XPS spectra, indicating that boron has been incorporated into the carbon matrix. Work supported by DOE-EERE, Award No. DE-FG36-08GO18142

  10. Accelerator-based epithermal neutron sources for boron neutron capture therapy of brain tumors.

    Science.gov (United States)

    Blue, Thomas E; Yanch, Jacquelyn C

    2003-01-01

    This paper reviews the development of low-energy light ion accelerator-based neutron sources (ABNSs) for the treatment of brain tumors through an intact scalp and skull using boron neutron capture therapy (BNCT). A major advantage of an ABNS for BNCT over reactor-based neutron sources is the potential for siting within a hospital. Consequently, light-ion accelerators that are injectors to larger machines in high-energy physics facilities are not considered. An ABNS for BNCT is composed of: (1) the accelerator hardware for producing a high current charged particle beam, (2) an appropriate neutron-producing target and target heat removal system (HRS), and (3) a moderator/reflector assembly to render the flux energy spectrum of neutrons produced in the target suitable for patient irradiation. As a consequence of the efforts of researchers throughout the world, progress has been made on the design, manufacture, and testing of these three major components. Although an ABNS facility has not yet been built that has optimally assembled these three components, the feasibility of clinically useful ABNSs has been clearly established. Both electrostatic and radio frequency linear accelerators of reasonable cost (approximately 1.5 M dollars) appear to be capable of producing charged particle beams, with combinations of accelerated particle energy (a few MeV) and beam currents (approximately 10 mA) that are suitable for a hospital-based ABNS for BNCT. The specific accelerator performance requirements depend upon the charged particle reaction by which neutrons are produced in the target and the clinical requirements for neutron field quality and intensity. The accelerator performance requirements are more demanding for beryllium than for lithium as a target. However, beryllium targets are more easily cooled. The accelerator performance requirements are also more demanding for greater neutron field quality and intensity. Target HRSs that are based on submerged-jet impingement and

  11. Mapping boron in silicon solar cells using electron energy-loss spectroscopy

    DEFF Research Database (Denmark)

    by focused ion beam milling in order to map the boron distribution across a 200-nm-thick n-p amorphous silicon junction using energy-filtered TEM and EELS spectrum acquisition. EELS line scans are used to detect boron concentrations as low as 10^20cm-3. We also use monochromated EELS to measure changes......Amorphous silicon solar cells typically consist of stacked layers deposited on plastic or metallic substrates making sample preparation for transmission electron microscopy (TEM) difficult. The amorphous silicon layer - the active part of the solar cell - is sandwiched between 10-nm-thick n- and p......-doped layers. The typical boron concentration in the p-doped layer is ~10^21cm -3 and should not exceed 1017cm-3 in the neighbouring intrinsic (i) layer [1], where it acts as a charge recombination centre and decreases the internal electric field [2]. The detection of low boron concentrations with high spatial...

  12. Defect characteristics by boron cluster ion implantation

    International Nuclear Information System (INIS)

    Aoki, Takaaki; Matsuo, Jiro; Takaoka, Gikan; Toyoda, Noriaki; Yamada, Isao

    2003-01-01

    Cluster ion implantation using decaborane (B 10 H 14 ) has been proposed as a shallow implantation technique for LSI devices with gate lengths of several-tens nanometers. Experiments and computer simulations of low-energy boron monomers and decaborane clusters implantation were performed. Molecular dynamics simulations of B 10 cluster implantation have shown similar implant depth but different damage density and damage structure compared to monomer (B 1 ) ion implantation with the same energy-per-atom. For monomer implantation, point-defects such as vacancy-interstitial pairs are mainly formed. On the other hand, B 10 generates large numbers of defects within a highly-amorphised region at the impact location. This difference in damage structure produced during implantation is expected to cause different annihilation processes

  13. An improved procedure for separation/purification of boron from complex matrices and high-precision measurement of boron isotopes by positive thermal ionization and multicollector inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Wei, Hai-Zhen; Jiang, Shao-Yong; Hemming, N Gary; Yang, Jing-Hong; Yang, Tao; Wu, He-Pin; Yang, Tang-Li; Yan, Xiong; Pu, Wei

    2014-06-01

    In order to eliminate boron loss and potential isotopic fractionation during chemical pretreatment of natural samples with complex matrices, a three-column ion-exchange separation/purification procedure has been modified, which ensures more than 98% recovery of boron from each step for a wide range of sample matrices, and is applicable for boron isotope analysis by both TIMS and MC-ICP-MS. The PTIMS-Cs2BO2(+)-static double collection method was developed, ensuring simultaneous collection of (133)Cs2(11)B(16)O2(+)(m/z 309) and (133)Cs2(10)B(16)O2(+) (m/z 308) ions in adjacent H3-H4 Faraday cups with typical zoom optics parameters (Focus Quad: 15 V, Dispersion Quad: -85 V). The external reproducibilities of the measured (11)B/(10)B ratios of the NIST 951 boron standard solutions of 1000 ng, 100 ng and 10 ng of boron by PTIMS method are ±0.06‰, ±0.16‰ and ±0.25‰, respectively, which indicates excellent precision can be achieved for boron isotope measurement at nanogram level boron in natural samples. An on-peak zero blank correction procedure was employed to correct the residual boron signals effect in MC-ICP-MS, which gives consistent δ(11)B values with a mean of 39.66±0.35‰ for seawater in the whole range of boron content from 5 ppb to 200 ppb, ensuring accurate boron isotope analysis in few ppb boron. With the improved protocol, consistent results between TIMS and MC-ICP-MS data were obtained in typical geological materials within a wide span of δ(11)B values ranging from -25‰ to +40‰. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Tribological properties of nitrogen implanted and boron implanted steels

    International Nuclear Information System (INIS)

    Kern, K.T.

    1996-01-01

    Samples of a steel with high chrome content was implanted separately with 75 keV nitrogen ions and with 75 keV boron ions. Implanted doses of each ion species were 2-, 4-, and 8 x 10 17 /cm 2 . Retained doses were measured using resonant non-Rutherford Backscattering Spectrometry. Tribological properties were determined using a pin-on-disk test with a 6-mm diameter ruby pin with a velocity of 0.94 m/min. Testing was done at 10% humidity with a load of 377 g. Wear rate and coefficient of friction were determined from these tests. While reduction in the wear rate for nitrogen implanted materials was observed, greater reduction (more than an order of magnitude) was observed for boron implanted materials. In addition, reduction in the coefficient of friction for high-dose boron implanted materials was observed. Nano-indentation revealed a hardened layer near the surface of the material. Results from grazing incidence x-ray diffraction suggest the formation of Fe 2 N and Fe 3 N in the nitrogen implanted materials and Fe 3 B in the boron implanted materials. Results from transmission electron microscopy will be presented

  15. Ammonium-tungstate-promoted growth of boron nitride nanotubes

    Science.gov (United States)

    E, Songfeng; Li, Chaowei; Li, Taotao; Geng, Renjie; Li, Qiulong; Lu, Weibang; Yao, Yagang

    2018-05-01

    Ammonium tungstate ((NH4)10W12O41 · xH2O) is a kind of oxygen-containing ammonium salt. The following study proves that it can be successfully used as a metal oxide alternative to produce boron oxide (B2O2) by oxidizing boron (B) in a traditional boron oxide chemical vapor deposition (BOCVD) process. This special oxidant promotes the simplistic fabrication of boron nitride nanotubes (BNNTs) in a conventional horizontal tube furnace, an outcome which may have resulted from its strong oxidizability. The experimental results demonstrate that the mole ratio of B and (NH4)10W12O41 · xH2O is a key parameter in determining the formation, quality and quantity of BNNTs when stainless steel is employed as a catalyst. We also found that Mg(NO3)2 and MgO nanoparticles (NPs) can be used as catalysts to grow BNNTs with the same precursor. The BNNTs obtained from the Mg(NO3)2 catalyst were straighter than those obtained from the MgO NP catalyst. This could have been due to the different physical forms of the catalysts that were used.

  16. Boronic acids for fluorescence imaging of carbohydrates.

    Science.gov (United States)

    Sun, Xiaolong; Zhai, Wenlei; Fossey, John S; James, Tony D

    2016-02-28

    "Fluorescence imaging" is a particularly exciting and rapidly developing area of research; the annual number of publications in the area has increased ten-fold over the last decade. The rapid increase of interest in fluorescence imaging will necessitate the development of an increasing number of molecular receptors and binding agents in order to meet the demand in this rapidly expanding area. Carbohydrate biomarkers are particularly important targets for fluorescence imaging given their pivotal role in numerous important biological events, including the development and progression of many diseases. Therefore, the development of new fluorescent receptors and binding agents for carbohydrates is and will be increasing in demand. This review highlights the development of fluorescence imaging agents based on boronic acids a particularly promising class of receptors given their strong and selective binding with carbohydrates in aqueous media.

  17. Advanced microstructure of boron carbide.

    Science.gov (United States)

    Werheit, Helmut; Shalamberidze, Sulkhan

    2012-09-26

    The rhombohedral elementary cell of the complex boron carbide structure is composed of B(12) or B(11)C icosahedra and CBC, CBB or B□B (□, vacancy) linear arrangements, whose shares vary depending on the actual chemical compound. The evaluation of the IR phonon spectra of isotopically pure boron carbide yields the quantitative concentrations of these components within the homogeneity range. The structure formula of B(4.3)C at the carbon-rich limit of the homogeneity range is (B(11)C) (CBC)(0.91) (B□B)(0.09) (□, vacancy); and the actual structure formula of B(13)C(2) is (B(12))(0.5)(B(11)C)(0.5)(CBC)(0.65)(CBB)(0.16) (B□B)(0.19), and deviates fundamentally from (B(12))CBC, predicted by theory to be the energetically most favourable structure of boron carbide. In reality, it is the most distorted structure in the homogeneity range. The spectra of (nat)B(x)C make it evident that boron isotopes are not randomly distributed in the structure. However, doping with 2% silicon brings about a random distribution.

  18. Boron isotopes in geothermal systems

    International Nuclear Information System (INIS)

    Aggarwal, J.

    1997-01-01

    Boron is a highly mobile element and during water-rock reactions, boron is leached out of rocks with no apparent fractionation. In geothermal systems where the water recharging the systems are meteoric in origin, the B isotope ratio of the geothermal fluid reflects the B isotope ratio of the rocks. Seawater has a distinctive B isotope ratio and where seawater recharges the geothermal system, the B isotope ratio of the geothermal system reflects the mixing of rock derived B and seawater derived B. Any deviations of the actual B isotope ratio of a mixture reflects subtle differences in the water-rock ratios in the cold downwelling limb of the hydrothermal system. This paper will present data from a variety of different geothermal systems, including New Zealand; Iceland; Yellowston, USA; Ibusuki, Japan to show the range in B isotope ratios in active geothermal systems. Some of these systems show well defined mixing trends between seawater and the host rocks, whilst others show the boron isotope ratios of the host rock only. In geothermal systems containing high amounts of CO 2 boron isotope ratios from a volatile B source can also be inferred. (auth)

  19. Structural characterization of electrodeposited boron

    Indian Academy of Sciences (India)

    electrolysis was crystalline in nature, X-ray diffraction pat-. ∗. Author for correspondence (sas@igcar.gov.in) .... Elemental boron was synthesized by the electrolysis of molten potassium fluroborate dissolved in a ... A high-throughput Renishaw micro-Raman spectrome- ter (model Invia) was employed to record Raman ...

  20. Preparation process of boron nitride

    International Nuclear Information System (INIS)

    Mignani, G.; Ardaud, P.

    1990-01-01

    High purity boron nitride, without Si and a low carbon content, is prepared by pyrolysis, under an ammoniac atmosphere, of the reaction product between a B-trihalogenoborazole and a primary amine RNH 2 when R is a hydrocarbon radical eventually substituted containing from 1 to 6 carbon atoms inclusively [fr

  1. Structural characterization of electrodeposited boron

    Indian Academy of Sciences (India)

    Structural characterization of electrodeposited boron was carried out by using transmission electron microscopy and Raman spectroscopy. Electron diffraction and phase contrast imaging were carried out by using transmission electron microscopy. Phase identification was done based on the analysis of electron diffraction ...

  2. Method of separating boron isotopes

    Science.gov (United States)

    Jensen, Reed J.; Thorne, James M.; Cluff, Coran L.; Hayes, John K.

    1984-01-01

    A method of boron isotope enrichment involving the isotope preferential photolysis of (2-chloroethenyl)dichloroborane as the feed material. The photolysis can readily be achieved with CO.sub.2 laser radiation and using fluences significantly below those required to dissociate BCl.sub.3.

  3. Prevention of uncontrolled boron dilution

    International Nuclear Information System (INIS)

    Sere, J. L.

    1997-01-01

    The paper presents a synthesis of the global analysis of uncontrolled boron dilution risk performed by (European Consortium Mochovce (EUCOM) in the frame of Safety Measures RC 01 and AA 11. Recommendation for additional improvements (mainly I and C interlocks or inhibition) are presented. (author)

  4. Epigenetic modification of miR-10a regulates renal damage by targeting CREB1 in type 2 diabetes mellitus.

    Science.gov (United States)

    Shan, Qun; Zheng, Guihong; Zhu, Aihua; Cao, Li; Lu, Jun; Wu, Dongmei; Zhang, ZiFeng; Fan, Shaohua; Sun, Chunhui; Hu, Bin; Zheng, Yuanlin

    2016-09-01

    Emerging evidence has shown that microRNA-mediated gene expression modulation plays a crucial role in the pathogenesis of type 2 diabetes mellitus, but the novel miRNAs involved in type 2 diabetes and its functional regulatory mechanisms still need to be determined. In this study, we assessed the role of miR-10a in extracellular matrix accumulation in the kidney of diabetic mellitus induced by combining administration of chronic high fat diet (HFD) and low dosage of streptozotocin (STZ, 35mg/kg). Here, we found that HFD/STZ administration decreased the level of microRNA (miR-10a) expression in ICR strain mice. Overexpression of miR-10a alleviated the increased ratio of urine albumin-to-creatinine (ACR) ratio of HFD/STZ mice. In contrast, knockdown of miR-10a increased the ratio of kidney ACR in naïve mice. Furthermore, cAMP response element binding protein 1 (CREB1) was validated as a target of miR-10a in vitro and in vivo. CREB1 and its downstream fibronectin (FN, extracellular matrix) were increased in HFD/STZ-treated mice, which was reversed by kidney miR-10a overexpression. The content of CREB1 and FN was increased by miR-10a knockdown in kidney of naïve mice. Furthermore, histone deacetylase 3 (HDAC3) was revealed to be increased in kidney of HFD/STZ mice, accompanied with the augmentation of ACR ratio and FN level. Knockdown of HDAC3 with siRNA significantly caused the increase of miR-10a, resulting in the decrease in CREB1 and FN expression in kidney of HFD/STZ mice. Contrarily, HDAC3 overexpression mediated by lentivirus decreased miR-10a content, and enhanced ACR value, CREB1 and FN formation in naïve mice. Collectively, these results elucidate that HDAC3/miR-10a/CREB1 serves as a new mechanism underlying kidney injury, providing potential therapeutic targets in type 2 diabetes. Copyright © 2016. Published by Elsevier Inc.

  5. Isotopic effect on thermal physical properties of isotopically modified boron single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Quanli [Japan Science and Technology Corporation, Kawaguchi, Saitama (Japan); Noda, Tetsuji; Suzuki, Hiroshi; Araki, Hiroshi; Numazawa, Takenori; Hirano, Toshiyuki [National Institute for Materials Science, Tsukuba, Ibaraki (Japan); Nogi, Naoyuki; Tanaka, Satoru [University of Tokyo, Department of Quantum Engineering and Systems Science, Tokyo (Japan)

    2002-04-01

    The measurement of specific heat and thermal conductivity at low temperature for isotopically modified boron single crystals was performed between 0.5 and 100K using relaxation method and steady heat flow method, respectively. The results indicate that the specific heat has obvious divergences at T<5K. At 40K, the thermal conductivity of {sup 10}B-enriched crystal is about 570 W/m{center_dot}K, which is 40% larger than that of natural boron crystal. The influence of lattice vibration modes and the isotopic effect on specific heat and thermal conductivity for isotopically modified boron are discussed. (author)

  6. SU-F-T-140: Assessment of the Proton Boron Fusion Reaction for Practical Radiation Therapy Applications Using MCNP6

    International Nuclear Information System (INIS)

    Adam, D; Bednarz, B

    2016-01-01

    Purpose: The proton boron fusion reaction is a reaction that describes the creation of three alpha particles as the result of the interaction of a proton incident upon a 11B target. Theoretically, the proton boron fusion reaction is a desirable reaction for radiation therapy applications in that, with the appropriate boron delivery agent, it could potentially combine the localized dose delivery protons exhibit (Bragg peak) and the local deposition of high LET alpha particles in cancerous sites. Previous efforts have shown significant dose enhancement using the proton boron fusion reaction; the overarching purpose of this work is an attempt to validate previous Monte Carlo results of the proton boron fusion reaction. Methods: The proton boron fusion reaction, 11B(p, 3α), is investigated using MCNP6 to assess the viability for potential use in radiation therapy. Simple simulations of a proton pencil beam incident upon both a water phantom and a water phantom with an axial region containing 100ppm boron were modeled using MCNP6 in order to determine the extent of the impact boron had upon the calculated energy deposition. Results: The maximum dose increase calculated was 0.026% for the incident 250 MeV proton beam scenario. The MCNP simulations performed demonstrated that the proton boron fusion reaction rate at clinically relevant boron concentrations was too small in order to have any measurable impact on the absorbed dose. Conclusion: For all MCNP6 simulations conducted, the increase of absorbed dose of a simple water phantom due to the 11B(p, 3α) reaction was found to be inconsequential. In addition, it was determined that there are no good evaluations of the 11B(p, 3α) reaction for use in MCNPX/6 and further work should be conducted in cross section evaluations in order to definitively evaluate the feasibility of the proton boron fusion reaction for use in radiation therapy applications.

  7. Targeting triple negative breast cancer cells by N3-substituted 9,10-Phenanthrenequinone thiosemicarbazones and their metal complexes

    Science.gov (United States)

    Afrasiabi, Zahra; Stovall, Preston; Finley, Kristen; Choudhury, Amitava; Barnes, Charles; Ahmad, Aamir; Sarkar, Fazlul; Vyas, Alok; Padhye, Subhash

    2013-10-01

    Novel N3-substituted 9,10-Phenanthrenequinone thiosemicarbazones and their copper, nickel and palladium complexes are structurally characterized and reported along with the single crystal X-ray structures of three ligands and one nickel complex. All compounds were evaluated for their antiproliferative potential against Triple Negative Breast Cancer (TNBC) cells which have poor prognosis and no effective drugs to treat with. All compounds exhibited antiproliferative activity against these cells. Among the metal complexes evaluated, redox active copper complexes were found to be more potent. The possible mechanism for such enhanced activity can be attributed to the generation of oxidative stress, which was amenable for targeting through metal complexation.

  8. Nuclear microprobe analysis of the selective boron uptake obtained with BPA in brain tumour tissue

    International Nuclear Information System (INIS)

    Wegden, M.; Kristiansson, P.; Ceberg, C.; Munck af Rosenschoeld, P.; Auzelyte, V.; Elfman, M.; Malmqvist, K.G.; Nilsson, C.; Pallon, J.; Shariff, A.

    2004-01-01

    The tumour selective ability of the boron compound boronophenylalanine (BPA), today used in Boron Neutron Capture Therapy in Sweden, has been investigated with the Lund Nuclear Microprobe. The tumour to tissue ratio of the boron concentration, as well as the location of boron within the cells, is critical for the efficiency of the therapy. It is desirable that the boron is accumulated as close as possible to the cell nucleus, since the alpha particles produced in the 10 B(n,α) 7 Li reaction only have a range of about 10 microns, i.e. a cell diameter. The nuclear reaction 11 B(p,α)2α, which has an especially high cross-section (300 mb) for 660 keV protons, has been used to analyse brain tissue from BPA-injected rats. Previous studies on other boron compounds have shown significant background problems when the alpha particles are detected in the backward direction. By a specially designed set-up, alpha particles in the forward and backward direction are detected simultaneously, and only the coincidences between the two directions are considered to be true boron events. In this way we could achieve excellent background suppression. The analysis shows that BPA indeed is tumour selective. Quantifications show a boron abundance of 150 ± 20 ng/cm 2 in normal tissue and 567 ± 70 ng/cm 2 in tumour tissue. If the rat is fed with L-dopa before the injection of BPA the uptake increases 3-4 times. The boron is homogeneously distributed in the cellular structure and no specific intracellular accumulation has been shown

  9. Analysis of boron carbides' electronic structure

    Science.gov (United States)

    Howard, Iris A.; Beckel, Charles L.

    1986-01-01

    The electronic properties of boron-rich icosahedral clusters were studied as a means of understanding the electronic structure of the icosahedral borides such as boron carbide. A lower bound was estimated on bipolaron formation energies in B12 and B11C icosahedra, and the associated distortions. While the magnitude of the distortion associated with bipolaron formation is similar in both cases, the calculated formation energies differ greatly, formation being much more favorable on B11C icosahedra. The stable positions of a divalent atom relative to an icosahedral borane was also investigated, with the result that a stable energy minimum was found when the atom is at the center of the borane, internal to the B12 cage. If incorporation of dopant atoms into B12 cages in icosahedral boride solids is feasible, novel materials might result. In addition, the normal modes of a B12H12 cluster, of the C2B10 cage in para-carborane, and of a B12 icosahedron of reduced (D sub 3d) symmetry, such as is found in the icosahedral borides, were calculated. The nature of these vibrational modes will be important in determining, for instance, the character of the electron-lattice coupling in the borides, and in analyzing the lattice contribution to the thermal conductivity.

  10. Boron modified molybdenum silicide and products

    International Nuclear Information System (INIS)

    Meyer, M.K.; Akinc, M.

    1999-01-01

    A boron-modified molybdenum silicide material is disclosed having the composition comprising about 80 to about 90 weight % Mo, about 10 to about 20 weight % Si, and about 0.1 to about 2 weight % B and a multiphase microstructure including Mo 5 Si 3 phase as at least one microstructural component effective to impart good high temperature creep resistance. The boron-modified molybdenum silicide material is fabricated into such products as electrical components, such as resistors and interconnects, that exhibit oxidation resistance to withstand high temperatures in service in air as a result of electrical power dissipation, electrical resistance heating elements that can withstand high temperatures in service in air and other oxygen-bearing atmospheres and can span greater distances than MoSi 2 heating elements due to improved creep resistance, and high temperature structural members and other fabricated components that can withstand high temperatures in service in air or other oxygen-bearing atmospheres while retaining creep resistance associated with Mo 5 Si 3 for structural integrity. 7 figs

  11. Boron neutron capture therapy for recurrent head and neck malignancies

    International Nuclear Information System (INIS)

    Kato, Itsuro; Ono, Koji; Sakurai, Yoshinori

    2006-01-01

    To avoid severe impairment of oro-facial structures and functions, it is necessary to explore new treatments for recurrent head and neck malignancies (HNM). Boron neutron capture therapy (BNCT) is tumor-cell targeted radiotherapy that has significant superiority over conventional radiotherapies in principle. So far for 4 years and 3 months, we have treated with 37 times of BNCT for 21 patients (14 squamous cell carcinomas (SCC), 4 salivary gland carcinomas and 3 sarcomas) with a recurrent and far advanced HNM since 2001. Results are (1) 10 B concentration of tumor/normal tissue ratio (T/N ratio) of FBPA-PET studies were SCC: 1.8-5.7, sarcoma: 2.5-4.0, parotid tumor: 2.5-3.7. (2) Therapeutic effects were CR: 6cases, PR: 11cases, PD: 3cases NE (not evaluated): 1case. Response rate was 81%. (3) Improvement of QOL such as a relief of severe pain, bleeding, and exudates at the local lesion, improvement of PS, disappearance of ulceration, covered with normal skin and preserved oral and maxillofacial functions and tissues. (4) Survival periods after BNCT were 1-51 months (mean: 9.8 months). 4-year survival rate was 39% by Kaplan-Meier analysis. (5) A few adverse-effects such as transient mucositis, alopecia were recognized. These results indicate that BNCT represents a new and promising treatment approach for advanced HNM. (author)

  12. Pressure-dependent boron isotopic fractionation observed by column chromatography

    Science.gov (United States)

    Musashi, M.; Oi, T.; Matsuo, M.; Nomura, M.

    2007-12-01

    Boron isotopic fractionation factor ( S ) between boron taken up in strongly basic anion exchange resin and boron in aqueous solution was determined by breakthrough column chromatography at 5 and 17 MPa at 25°C, using 0.1 mmol/L boric acid solution as feed solution. The S values obtained were 1.018 and 1.012, respectively, which were smaller than the value reported by using the same chromatographic method at atmospheric pressure at 25°C with the boron concentration of 10 mmol/L, but were larger than the values at the same condition with much higher concentration of 100 and 501 mmol/L, indicating that borate-polymerization reducing the isotopic fractionation was negligible. However, calculations based on the theory of isotope distribution between two phases estimated that 21% (5MPa) and 47% (17MPa) of boron taken up in the resin phase was in the three-coordinated B(OH)3-form, instead of in the four-coordinated B(OH)4--form, at high pressures even with the very diluted solution. We discussed this discrepancy by introducing (1) hydration or (2) a partial molar volume difference between isotopic molecules. It was inferred that borate ions were partially dehydrated upon transfer from the solution phase to the resin phase at high pressures, which resulted in smaller S values compared with those at the atmospheric pressure. Alternatively, it was likely that the S value decreased with increasing pressure, because the difference of the partial isotopic molar volumes between 10B(OH)3 and 11B(OH)3 was larger than that between 10B(OH)4- and 11B(OH)4-. If either will be the case, the influence of a pressure upon the isotope effect may not be negligible for boron isotopic exchange equilibrium. This knowledge is crucial for the principle of the boron isotopic pH-metry reconstructing a chemical variation at the paleo-deep oceanic environment where the early life may have been evolved.

  13. Effects of boron-water on cattle

    Energy Technology Data Exchange (ETDEWEB)

    Green, G.H.; Weeth, H.J.

    1975-01-01

    To determine the effects of subtoxic concentrations of boron in drinking water, 12 Hereford heifers were used in a 3 x 3 latin-square experiment with four squares. Treatments were tap-water (0.8 ppm boron), 150 ppm boron-water, and 300 ppm boron-water. Periods were 30 days each. Total urine was collected during the last week of each period, and renal clearance observations (based on creatinine) were made on the last day of each period. While water consumption and total urine weight were not affected by the boron treatments, hay consumption decreased, and weight loss was noted. Plasma boron concentrations were 0.53 +/- 0.151 ppm, 11.2 +/- 0.91 ppm, and 18.9 +/- 0.60 ppm while the heifers were drinking tap-water, 150 ppm boron-water, and 300 ppm boron-water respectively. Urinary boron excretion rates were tap water, 64 +/- 5.6 mg/day; 150 ppm, 2841 +/- 181.2 mg/day; 300 ppm, 4932 +/- 173.3 mg/day. Although glomerular filtration and osmolal clearance were unaffected by the boron-waters, a relative diuresis was indicated by the free water clearance effects. The percent of filtered boron which was reabsorbed decreased with increased exogenous boron, as well as both plasma and urinary phosphate. These data indicate that 300 ppm boron is not acutely toxic to heifers when consumed via the drinking water. The safe tolerance concentration, however, must lie below 150 ppm because this concentration was responsible for some deleterious effects.

  14. Boron evaporation in thermally-driven seawater desalination: Effect of temperature and operating conditions.

    Science.gov (United States)

    Alpatova, A; Alsaadi, A; Ghaffour, N

    2018-06-05

    The volatilization of boron in thermal desalination processes, namely multi-stage flash (MSF) and air-gap membrane distillation (AGMD) was investigated for the first time. This phenomenon was observed at feed temperatures above 55 °C in both studied processes. In simulated MSF process with two feeds, model boric acid and Red Sea water, boron concentration in distillate increased with feed temperature increase from 55 °C to 104 °C because of the increase in boric acid vapor pressure. Salinity and pH were the main factors controlling boron evaporation. The achieved boron concentrations in simulated MSF process were consistent with those measured in distillate samples collected from commercial MSF plants. The AGMD process also revealed a strong influence of operating temperature on boron removal. However, unlike MSF process, the boron concentration in AGMD permeate decreased with the feed temperature increase from 55 °C to 80 °C due probably to increase in vapor production and corresponding permeate dilution. When AGMD was operated in concentrating mode at a constant feed temperature of 80 °C, permeate boron concentration increased with process time due to concentration polarization and membrane fouling. A 10% flux decline observed after 21 h was attributed to CaCO 3 scaling on the membrane surface. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Controlling the Morphology and Oxidation Resistance of Boron Carbide Synthesized Via Carbothermic Reduction Reaction

    Science.gov (United States)

    Ahmed, Yasser M. Z.; El-Sheikh, Said M.; Ewais, Emad M. M.; Abd-Allah, Asmaa A.; Sayed, Said A.

    2017-03-01

    Boron carbide powder was synthesized from boric acid and lactose mixtures via easy procedure. Boric acid and lactose solution mixtures were roasted in stainless steel pot at 280 °C for 24 h. Boron carbide was obtained by heating the roasted samples under flowing of industrial argon gas at 1500 °C for 3 h. The amount of borate ester compound in the roasted samples was highly influenced by the boron/carbon ratio in the starting mixtures and plays a versatile role in the produced boron carbide. The high-purity boron carbide powder was produced with a sample composed of lowest boron/carbon ratio of 1:1 without calcination step. Particle morphology was changed from nano-needles like structure of 8-10 nm size with highest carbon ratio mixture to spherical shape of >150 nm size with lowest one. The oxidation resistance performance of boron carbide is highly dependent on the morphology and grain size of the synthesized powder.

  16. Boron evaporation in thermally-driven seawater desalination: Effect of temperature and operating conditions

    KAUST Repository

    Alpatova, Alla

    2018-03-26

    The volatilization of boron in thermal desalination processes, namely multi-stage flash (MSF) and air-gap membrane distillation (AGMD) was investigated for the first time. This phenomenon was observed at feed temperatures above 55 °C in both studied processes. In simulated MSF process with two feeds, model boric acid and Red Sea water, boron concentration in distillate increased with feed temperature increase from 55 °C to 104 °C because of the increase in boric acid vapor pressure. Salinity and pH were the main factors controlling boron evaporation. The achieved boron concentrations in simulated MSF process were consistent with those measured in distillate samples collected from commercial MSF plants. The AGMD process also revealed a strong influence of operating temperature on boron removal. However, unlike MSF process, the boron concentration in AGMD permeate decreased with the feed temperature increase from 55 °C to 80 °C due probably to increase in vapor production and corresponding permeate dilution. When AGMD was operated in concentrating mode at a constant feed temperature of 80 °C, permeate boron concentration increased with process time due to concentration polarization and membrane fouling. A 10% flux decline observed after 21 h was attributed to CaCO scaling on the membrane surface.

  17. The All Boron Carbide Diode Neutron Detector: Experiment and Modeling Approach

    International Nuclear Information System (INIS)

    Sabirianov, Ildar F.; Brand, Jennifer I.; Fairchild, Robert W.

    2008-01-01

    Boron carbide diode detectors, fabricated from two different polytypes of semiconducting boron carbide, will detect neutrons in reasonable agreement with theoretical expectations. The performance of the all boron carbide neutron detector differs, as expected, from devices where a boron rich neutron capture layer is distinct from the diode charge collection region (i.e. a conversion layer solid state detector). Diodes were fabricated from natural abundance boron (20% 10 B and 80% 11 B.) directly on the metal substrates and metal contacts applied to the films as grown. The total boron depth was on the order of 2 microns. This is clearly not a conversion-layer configuration. The diodes were exposed to thermal neutrons generated from a paraffin moderated plutonium-beryllium source in moderated and un-moderated, as well as shielded and unshielded experimental configurations, where the expected energy peaks at at 2.31 MeV and 2.8 MeV were clearly observed, albeit with some incomplete charge collection typical of thinner diode structures. The results are compared with other boron based thin film detectors and literature models. (authors)

  18. Electronic response of a photodiode coupled to a boron thin film

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Priscila; Costa, Fabio E.; Raele, Marcus P.; Zahn, Guilherme S.; Geraldo, Bianca; Vieira Junior, Nilson D.; Samad, Ricardo E.; Genezini, Frederico A., E-mail: priscila3.costa@usp.br, E-mail: fredzini@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

    2017-07-01

    A portable thermal neutron detector is proposed in this work using a silicon photodiode coupled to a boron thin film. The aim of this work was to verify the effect in the electronic response of this specific photodiode due to boron deposition, since the direct deposition of boron in the semiconductor surface could affect its electrical properties specifically the p-type layer that affects directly the depletion region of the semiconductor reducing the neutron detector efficiency count. Three boron depositions with different thickness were performed in the photodiode (S3590-09) surface by pulsed laser deposition and the photodiode was characterized, before and after the deposition process, using a radioactive americium source. Energy spectra were used to verify the electronic response of the photodiode, due to the fact that it is possible to relate it to the photopeak pulse height and resolution. Spectra from the photodiode without and with boron film deposition were compared and a standard photodiode (S3590-04) that had the electronic signal conserved was used as reference to the pulse height for electronics adjustments. The photopeak energy resolution for the photodiode without boron layer was 10.26%. For the photodiode with boron deposition at different thicknesses, the resolution was: 7.64 % (0.14 μm), 7.30 % (0.44 μm) and 6.80 % (0.63 μm). From these results it is possible to evaluate that there was not any degradation in the silicon photodiode. (author)

  19. Monte-Carlo simulation of primary stochastic effects induced at the cellular level in boron neutron capture therapy; Simulation Monte-Carlo des effets stochastiques primaires induits au niveau cellulaire lors de la therapie par capture de neutrons sur le {sup 10}B

    Energy Technology Data Exchange (ETDEWEB)

    Cirioni, L.; Patau, J.P.; Nepveu, F. [Universite Paul Sabatier, 31 - Toulouse (France)

    1998-04-01

    A Monte Carlo code is developed to study the action of particles in Boron Neutron Capture Therapy (BNCT). Our aim is to calculate the probability of dissipating a lethal dose in cell nuclei. Cytoplasmic and nuclear membranes are considered as non-concentric ellipsoids. All geometrical parameters may be adjusted to fit actual configurations. The reactions {sup 10}B(n,{gamma} {alpha}){sup 7}Li and {sup 14}N(n,p) {sup 14}C create heavy ions which slow clown losing their energy. Their trajectories can be simulated taking into account path length straggling. The contribution of each reaction to the deposited dose in different cellular compartments can be studied and analysed for any distribution of {sup 10}B. (authors)

  20. The cross-section of the 10B(n,α)7Li reaction measured in the MeV energy range

    International Nuclear Information System (INIS)

    Giorginis, Georgios; Khryachkov, Vitali

    2006-01-01

    The excitation function of the 10 B(n,α) 7 Li reaction was measured between 1.5 and 5.6 MeV within the frame of the IAEA Coordinated Research Project (CRP) on 'Improvement of the Standard Cross Sections for Light Elements'. An ionisation chamber and signal digitisation were used for the spectrometry of the reaction products, which were forwards emitted by bombarding a thin boron target with neutrons produced at the IRMM Van de Graaff accelerator. The neutron flux was determined by measuring the backwards emitted fission fragments from a 238 U sample mounted in a back-to-back geometry relative to the boron target. The highlight of this study was the discovery of the kinematic effect of particle leaking, which is very important for the accurate determination of the number of the boron reaction events. The experiment is described and the results are discussed and compared with evaluations and experimental data of other groups

  1. Diffuse X-ray scattering from neutron-irradiated silicon doped with boron

    International Nuclear Information System (INIS)

    Mayer, W.; Grasse, D.; Peisl, J.

    1985-01-01

    The diffuse X-ray scattering and lattice parameter change of silicon crystals heavily doped with boron after electron and neutron irradiation are measured. From a comparison of unirradiated and electron-irradiated samples the volume change is determined of substitutional boron Q/sub B/ = -(2.2 +- 0.2) x 10 -2 nm 3 and of boron with a trapped interstitial Q/sub BI/ = (0 +- 0.5) x 10 -2 nm 3 . During neutron irradiation of the doped samples each boron stabilizes an additional Frenkel pair by trapping of the interstitial. The concentration of the untrapped interstitials remains the same as in the undoped sample, but the nucleation of interstitial clusters is enhanced thus reducing the cluster size to 93% of the value of undoped samples. (author)

  2. LBNE lattice and optics for proton extraction at MI-10 and transport to a target above grade

    International Nuclear Information System (INIS)

    Johnstone, John A.

    2011-01-01

    For the Long Baseline Neutrino Experiment (LBNE) at Fermilab 120 GeV/c protons will be transported from the Main Injector (MI) to an on-site production target. The lattice design and optics discussed here has the beam extracted vertically upwards from MI-10 and the keeps the majority of the line at an elevation above the glacial till/rock interface and terminates on a target at 10 ft above grade. The LBNE beamline discussed here is a modular optics design comprised of 3 distinct lattice configurations, including the specialized MI → LBNE matching section and Final Focus. The remainder of the line is defined by six FODO cells, in which the length and phase advance are chosen specifically such that beam size does not exceed that of the MI while also making the most efficient use of space for achromatic insertions. Dispersion generated by variations in the beam trajectory are corrected locally and can not bleed out to corrupt the optics elsewhere in the line. Aperture studies indicate that the line should be able to transport the worst quality beam that the Main Injector might provide. New IDS dipole correctors located at every focusing center provide high-quality orbit control and further ensure that LBNE meets the stringent requirements for environmental protection.

  3. Re-sintered boron-rich polycrystalline cubic boron nitride and method for making same

    Energy Technology Data Exchange (ETDEWEB)

    Lavens, T.R.; Corrigan, F.R.; Shott, R.L.; Bovenkerk, H.P.

    1987-06-16

    A method is described for making re-sintered polycrystalline cubic boron nitride (CBN) which comprises: (a) placing sintered substantially catalyst-free boron-rich polycrystalline cubic boron nitride particles in a high pressure/high temperature apparatus, the particles being substantially free of sintering inhibiting impurities; (b) subjecting the boron-rich cubic boron nitride particles to a pressure and a temperature adequate to re-sinter the particles, the temperature being below the CBN reconversion temperature; (c) maintaining the temperature and pressure for a time sufficient to re-sinter the boron-rich cubic boron nitride particles in the apparatus, and (d) recovering the re-sintered polycrystalline cubic boron nitride from the apparatus.

  4. Sputtered boron indium oxide thin-film transistors

    Science.gov (United States)

    Stewart, Kevin A.; Gouliouk, Vasily; Keszler, Douglas A.; Wager, John F.

    2017-11-01

    Boron indium oxide (BIO) is studied for thin-film transistor (TFT) channel layer applications. Sputtered BIO thin films exhibit an amorphous phase over a wide range of B2O3/In2O3 ratios and remain amorphous up to 500 °C. The band gap decreases linearly with decreasing boron content, whereas device performance generally improves with decreasing boron content. The best amorphous BIO TFT exhibits a field-effect mobility of 10 cm2 V-1 s-1, turn-on voltage of 2.5 V, and sub-threshold swing of 0.72 V/dec. Decreasing the boron content to 12.5% leads to a polycrystalline phase, but further increases the mobility up to 20-40 cm2 V-1 s-1. TCAD simulation results suggest that the reason for higher performance after increasing the anneal temperature from 200 to 400 °C is due to a lower defect density in the sub-bandgap region of the BIO channel layer.

  5. Boron isotope fractionation in magma via crustal carbonate dissolution.

    Science.gov (United States)

    Deegan, Frances M; Troll, Valentin R; Whitehouse, Martin J; Jolis, Ester M; Freda, Carmela

    2016-08-04

    Carbon dioxide released by arc volcanoes is widely considered to originate from the mantle and from subducted sediments. Fluids released from upper arc carbonates, however, have recently been proposed to help modulate arc CO2 fluxes. Here we use boron as a tracer, which substitutes for carbon in limestone, to further investigate crustal carbonate degassing in volcanic arcs. We performed laboratory experiments replicating limestone assimilation into magma at crustal pressure-temperature conditions and analysed boron isotope ratios in the resulting experimental glasses. Limestone dissolution and assimilation generates CaO-enriched glass near the reaction site and a CO2-dominated vapour phase. The CaO-rich glasses have extremely low δ(11)B values down to -41.5‰, reflecting preferential partitioning of (10)B into the assimilating melt. Loss of (11)B from the reaction site occurs via the CO2 vapour phase generated during carbonate dissolution, which transports (11)B away from the reaction site as a boron-rich fluid phase. Our results demonstrate the efficacy of boron isotope fractionation during crustal carbonate assimilation and suggest that low δ(11)B melt values in arc magmas could flag shallow-level additions to the subduction cycle.

  6. Boron isotope fractionation in magma via crustal carbonate dissolution

    Science.gov (United States)

    Deegan, Frances M.; Troll, Valentin R.; Whitehouse, Martin J.; Jolis, Ester M.; Freda, Carmela

    2016-08-01

    Carbon dioxide released by arc volcanoes is widely considered to originate from the mantle and from subducted sediments. Fluids released from upper arc carbonates, however, have recently been proposed to help modulate arc CO2 fluxes. Here we use boron as a tracer, which substitutes for carbon in limestone, to further investigate crustal carbonate degassing in volcanic arcs. We performed laboratory experiments replicating limestone assimilation into magma at crustal pressure-temperature conditions and analysed boron isotope ratios in the resulting experimental glasses. Limestone dissolution and assimilation generates CaO-enriched glass near the reaction site and a CO2-dominated vapour phase. The CaO-rich glasses have extremely low δ11B values down to -41.5‰, reflecting preferential partitioning of 10B into the assimilating melt. Loss of 11B from the reaction site occurs via the CO2 vapour phase generated during carbonate dissolution, which transports 11B away from the reaction site as a boron-rich fluid phase. Our results demonstrate the efficacy of boron isotope fractionation during crustal carbonate assimilation and suggest that low δ11B melt values in arc magmas could flag shallow-level additions to the subduction cycle.

  7. Recombination and photosensitivity centres in boron nitride irradiated with ions

    International Nuclear Information System (INIS)

    Kabyshev, A.; Konusov, F.; Lopatin, V.

    2001-01-01

    The physical-chemical processes, taking place during the irradiation of dielectrics with ions distort the electron structure of the compounds and generate additional localise state in the forbidden zone (FZ). Consequently, the semiconductor layer with the specific surface density of σ ≥ 10 -10 S/ forms on the surface of the dielectric. In addition to his, the high concentration of the radiation-induced defects changes the optical and photoelectric properties of the materials and also the energy characteristics. Analysis of the photoelectric properties indicates that the recombination processes take part in electric transport. These processes restricted the increase of the photosensitivity and changing the kinetics of relaxation of photo conductivity (σ hv ). The practical application of the boron nitride (BN) the in the thermonuclear systems (for example, Ref. 7), stimulates research into the reasons for the deceleration of its properties under the effect of radiation of various types. The conductivity of non-irradiated boron nitride is of the electron-hole nature with a large fraction of the activation component in exchange of the charge carriers between the levels of the defects and the forbidden zones. On the basis of the correlation of the energy and kinetic parameters of luminescence and , the authors of Ref. 8 constructed a model of electron transfers accompanying the electric transport of the boron nitride. In addition to ion-thermal modification, the conductivity of boron nitride is also of the electron-hole nature and is accompanied by luminescence. Examination of the characteristics of luminescence may be useful for obtaining more information on the transport mechanism. In this work, in order to clarify the main parameters of the forbidden band, detailed investigations were carried out into the spectrum of the electronic states of radiation defects which determine the photoelectric and luminescence properties of the modified boron nitride. The

  8. Boron Neutron Capture Therapy in the Treatment of Recurrent Laryngeal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Haapaniemi, Aaro, E-mail: aaro.haapaniemi@hus.fi [Department of Otorhinolaryngology–Head and Neck Surgery, Helsinki University Hospital and University of Helsinki, Helsinki (Finland); Kankaanranta, Leena [Department of Oncology, Helsinki University Hospital and University of Helsinki, Helsinki (Finland); Saat, Riste [Department of Radiology, Helsinki University Hospital and University of Helsinki, Helsinki (Finland); Koivunoro, Hanna; Saarilahti, Kauko [Department of Oncology, Helsinki University Hospital and University of Helsinki, Helsinki (Finland); Mäkitie, Antti; Atula, Timo [Department of Otorhinolaryngology–Head and Neck Surgery, Helsinki University Hospital and University of Helsinki, Helsinki (Finland); Joensuu, Heikki [Department of Oncology, Helsinki University Hospital and University of Helsinki, Helsinki (Finland)

    2016-05-01

    Purpose: To investigate the safety and efficacy of boron neutron capture therapy (BNCT) as a larynx-preserving treatment option for patients with recurrent laryngeal cancer. Methods and Materials: Six patients with locally recurrent squamous cell laryngeal carcinoma and 3 patients with persistent laryngeal cancer after prior treatment were treated with BNCT at the FiR1 facility (Espoo, Finland) in 2006 to 2012. The patients had received prior radiation therapy with or without concomitant chemotherapy to a cumulative median dose of 66 Gy. The median tumor diameter was 2.9 cm (range, 1.4-10.9 cm) before BNCT. Boron neutron capture therapy was offered on a compassionate basis to patients who either refused laryngectomy (n=7) or had an inoperable tumor (n=2). Boronophenylalanine-fructose (400 mg/kg) was used as the boron carrier and was infused over 2 hours intravenously before neutron irradiation. Results: Six patients received BNCT once and 3 twice. The estimated average gross tumor volume dose ranged from 22 to 38 Gy (W) (mean; 29 Gy [W]). Six of the 8 evaluable patients responded to BNCT; 2 achieved complete and 4 partial response. One patient died early and was not evaluable for response. Most common side effects were stomatitis, fatigue, and oral pain. No life-threatening or grade 4 toxicity was observed. The median time to progression within the target volume was 6.6 months, and the median overall survival time 13.3 months after BNCT. One patient with complete response is alive and disease-free with a functioning larynx 60 months after BNCT. Conclusions: Boron neutron capture therapy given after prior external beam radiation therapy is well tolerated. Most patients responded to BNCT, but long-term survival with larynx preservation was infrequent owing to cancer progression. Selected patients with recurrent laryngeal cancer may benefit from BNCT.

  9. Determination of the boron content in polyethylene samples using the reactor Orphée

    CERN Document Server

    Gunsing, F; Aberle, O

    2017-01-01

    The boron content of two unknown types of polyethylene has been determined relative to a known reference type. Samples of polyethylene, including a known boron-less one, were irradiated with thermal neutrons at the reactor Orphée at Saclay in France. Prompt gamma rays were measured with a CeBr$_3$ detector and the intensity of the 478~keV line from $^{10}${B}(n,$\\alpha_1\\gamma$)$^{7}{Li*} was extracted.

  10. Structure and superconductivity of isotope-enriched boron-doped diamond

    OpenAIRE

    Evgeny A Ekimov, Vladimir A Sidorov, Andrey V Zoteev, Yury B Lebed, Joe D Thompson and Sergey M Stishov

    2008-01-01

    Superconducting boron-doped diamond samples were synthesized with isotopes of 10B, 11B, 13C and 12C. We claim the presence of a carbon isotope effect on the superconducting transition temperature, which supports the ‘diamond-carbon’-related nature of superconductivity and the importance of the electron–phonon interaction as the mechanism of superconductivity in diamond. Isotope substitution permits us to relate almost all bands in the Raman spectra of heavily boron-doped diamond to the vibrat...

  11. Model for the boron-doping dependence of the critical temperature of superconducting boron-doped diamond

    Czech Academy of Sciences Publication Activity Database

    Šopík, Břetislav

    2009-01-01

    Roč. 11, č. 10 (2009), 103026/1-103026/10 ISSN 1367-2630 R&D Projects: GA AV ČR IAA100100712 Grant - others:GAČR(CZ) GA202/07/0597 Institutional research plan: CEZ:AV0Z10100521 Keywords : superconductivity * boron-doped diamond Subject RIV: BE - Theoretical Physics Impact factor: 3.312, year: 2009

  12. Targeted deletion of Sox10 by Wnt1-cre defects neuronal migration and projection in the mouse inner ear.

    Directory of Open Access Journals (Sweden)

    YanYan Mao

    Full Text Available Sensory nerves of the brainstem are mostly composed of placode-derived neurons, neural crest-derived neurons and neural crest-derived Schwann cells. This mixed origin of cells has made it difficult to dissect interdependence for fiber guidance. Inner ear-derived neurons are known to connect to the brain after delayed loss of Schwann cells in ErbB2 mutants. However, the ErbB2 mutant related alterations in the ear and the brain compound interpretation of the data. We present here a new model to evaluate exclusively the effect of Schwann cell loss on inner ear innervation. Conditional deletion of the neural crest specific transcription factor, Sox10, using the rhombic lip/neural crest specific Wnt1-cre driver spares Sox10 expression in the ear. We confirm that neural crest-derived cells provide a stop signal for migrating spiral ganglion neurons. In the absence of Schwann cells, spiral ganglion neurons migrate into the center of the cochlea and even out of the ear toward the brain. Spiral ganglion neuron afferent processes reach the organ of Corti, but many afferent fibers bypass the organ of Corti to enter the lateral wall of the cochlea. In contrast to this peripheral disorganization, the central projection to cochlear nuclei is normal. Compared to ErbB2 mutants, conditional Sox10 mutants have limited cell death in spiral ganglion neurons, indicating that the absence of Schwann cells alone contributes little to the embryonic survival of neurons. These data suggest that neural crest-derived cells are dispensable for all central and some peripheral targeting of inner ear neurons. However, Schwann cells provide a stop signal for migratory spiral ganglion neurons and facilitate proper targeting of the organ of Corti by spiral ganglion afferents.

  13. Boron removal by the duckweed Lemna gibba: a potential method for the remediation of boron-polluted waters.

    Science.gov (United States)

    Del-Campo Marín, Claudia M; Oron, Gideon

    2007-12-01

    Boron (B) is often found in polluted and desalinated waters. Despite its potentially environmental damaging effects, efficient treatments are lacking. The duckweed Lemna gibba has been shown to remove toxic elements from water; however, its applicability to B removal is unknown. In this study, L. gibba was examined for its tolerance to B in water and its B removal efficiency. Duckweed plants were grown in outdoor 12-day batch experiments in nutrient solution containing 0.3-10 mg B L(-1). Plant biomass production was not affected by B over the tested concentrations during the 12-day cultivation period. Boron removal and the bioconcentration factor of B in L. gibba were highest at initial B concentrations below 2 mg L(-1), and decreased as the initial B concentration increased. Boron content in the plants at the end of the experiment ranged between 930 and 1900 mg kg(-1) dry weight, and was comparable to that of wetland plants reported to be good B accumulators. Boron removal by L. gibba may therefore be a suitable option for the treatment of water containing B concentrations below 2 mg L(-1).

  14. Potent and Selective Peptidyl Boronic Acid Inhibitors of the Serine Protease Prostate-Specific Antigen

    Science.gov (United States)

    LeBeau, Aaron M.; Singh, Pratap; Isaacs, John T.; Denmeade, Samuel R.

    2012-01-01

    SUMMARY Prostate cancer cells produce high (microgram to milligram/milliliter) levels of the serine protease Prostate-Specific Antigen (PSA). PSA is enzymatically active in the extracellular fluid surrounding prostate cancers but is found at 1,000- to 10,000-fold lower concentrations in the circulation, where it is inactivated due to binding to abundant serum protease inhibitors. The exclusive presence of high levels of active PSA within prostate cancer sites makes PSA an attractive candidate for targeted imaging and therapeutics. A synthetic approach based on a peptide substrate identified first peptide aldehyde and then boronic acid inhibitors of PSA. The best of these had the sequence Cbz-Ser-Ser-Lys-Leu-(boro)Leu, with a Ki for PSA of 65 nM. The inhibitor had a 60-fold higher Ki for chymotrypsin. A validated model of PSA’s catalytic site confirmed the critical interactions between the inhibitor and residues within the PSA enzyme. PMID:18635003

  15. Boron clusters in luminescent materials.

    Science.gov (United States)

    Mukherjee, Sanjoy; Thilagar, Pakkirisamy

    2016-01-21

    In recent times, luminescent materials with tunable emission properties have found applications in almost all aspects of modern material sciences. Any discussion on the recent developments in luminescent materials would be incomplete if one does not account for the versatile photophysical features of boron containing compounds. Apart from triarylboranes and tetra-coordinate borate dyes, luminescent materials consisting of boron clusters have also found immense interest in recent times. Recent studies have unveiled the opportunities hidden within boranes, carboranes and metalloboranes, etc. as active constituents of luminescent materials. From simple illustrations of luminescence, to advanced applications in LASERs, OLEDs and bioimaging, etc., the unique features of such compounds and their promising versatility have already been established. In this review, recent revelations about the excellent photophysical properties of such materials are discussed.

  16. Isotope engineering of van der Waals interactions in hexagonal boron nitride

    Science.gov (United States)

    Vuong, T. Q. P.; Liu, S.; van der Lee, A.; Cuscó, R.; Artús, L.; Michel, T.; Valvin, P.; Edgar, J. H.; Cassabois, G.; Gil, B.

    2018-02-01

    Hexagonal boron nitride is a model lamellar compound where weak, non-local van der Waals interactions ensure the vertical stacking of two-dimensional honeycomb lattices made of strongly bound boron and nitrogen atoms. We study the isotope engineering of lamellar compounds by synthesizing hexagonal boron nitride crystals with nearly pure boron isotopes (10B and 11B) compared to those with the natural distribution of boron (20 at% 10B and 80 at% 11B). On the one hand, as with standard semiconductors, both the phonon energy and electronic bandgap varied with the boron isotope mass, the latter due to the quantum effect of zero-point renormalization. On the other hand, temperature-dependent experiments focusing on the shear and breathing motions of adjacent layers revealed the specificity of isotope engineering in a layered material, with a modification of the van der Waals interactions upon isotope purification. The electron density distribution is more diffuse between adjacent layers in 10BN than in 11BN crystals. Our results open perspectives in understanding and controlling van der Waals bonding in layered materials.

  17. Removal of boron (B) from waste liquors.

    Science.gov (United States)

    Jiang, J Q; Xu, Y; Simon, J; Quill, K; Shettle, K

    2006-01-01

    This paper explores the use of electrocoagulation to remove boron from waste effluent in comparison with alum coagulation. In treating model test wastes, greater boron removals were achieved with electrocoagulation at low doses than conventional alum coagulation when reaction was undertaken for the same conditions (pH 8.5, and initial boron concentration was 500 mg/L). Al electrocoagulation can achieve good boron removal performance (68.3%) at a dose of 2.1 (as molar ratio of Al:B, and for current density of 62.1 A/m2), while alum coagulation can only achieve the maximum boron removal of 56% at a dose of 2.4. Also, Al electrocoagulation can remove 15-20% more boron than alum coagulation for the same dose compared in the treatment of both model test wastes and industry effluent. The estimation of running costs shows that to achieve 75% boron removal from industry waste effluent, i.e. removing 150 g of boron from 1 m3 of effluent, electrocoagulation was 6.2 times cheaper than alum coagulation. The economic advantage of electrocoagulation in the treatment of boron-containing waste effluent is thus significant.

  18. The boron geochemistry of siliceous sponges

    Science.gov (United States)

    de Leon, A.; Wille, M.; Eggins, S. M.; Ellwood, M. J.

    2009-12-01

    The boron content and isotopic composition (δ11B) of marine carbonate organisms can be linked to the pH of the seawater in which they have grown, making carbonates a useful tool for palaeo-seawater pH reconstruction. A study by Furst (1981) documented unusually high boron concentrations in siliceous sponge spicules, in range from hundreds to a thousand ppm. This observation and the potential for preferential incorporation of the tetrahedral borate species into biogenic silica raises the question as to whether the boron chemistry of biogenic silica might also be influenced by seawater pH. We have measured the boron concentration and isotopic composition of siliceous sponges from the Southern Ocean region, with a view to (1) confirming the observations of Furst (1981), (2) assessing the factors that control boron incorporation and isotopic compositions of sponge silica, and (3) investigating the potentially significant role of siliceous sponges in the marine boron cycle. The measured boron concentrations in a diverse range of both demosponge and hexactinellid sponges confirm the high boron concentrations previously reported. The boron isotope compositions of these sponges vary from around +2‰ to +25‰ and greatly exceed the range in marine carbonates. This isotopic variation is inconsistent with seawater pH control but is correlated with ambient seawater silicon concentration, in a manner that suggests a link to silicon uptake kinetics and demand by sponges.

  19. Mineral resource of the month: boron

    Science.gov (United States)

    Crangle, Robert D.

    2012-01-01

    The article offers information on the mineral, boron. Boron compounds, particularly borates, have more commercial applications than its elemental relative which is a metalloid. Making up the 90% of the borates that are used worldwide are colemanite, kernite, tincal, and ulexite. The main borate deposits are located in the Mojave Desert of the U.S., the Tethyan belt in southern Asia, and the Andean belt of South America. Underground and surface mining are being used in gathering boron compounds. INSETS: Fun facts;Boron production and consumption.

  20. Conduction mechanism in boron carbide

    Science.gov (United States)

    Wood, C.; Emin, D.

    1984-01-01

    Electrical conductivity, Seebeck-coefficient, and Hall-effect measurements have been made on single-phase boron carbides, B(1-x)C(x), in the compositional range from 0.1 to 0.2 X, and between room temperature and 1273 K. The results indicate that the predominant conduction mechanism is small-polaron hopping between carbon atoms at geometrically inequivalent sites.

  1. An Exploration of Neutron Detection in Semiconducting Boron Carbide

    Science.gov (United States)

    Hong, Nina

    The 3He supply problem in the U.S. has necessitated the search for alternatives for neutron detection. The neutron detection efficiency is a function of density, atomic composition, neutron absorption cross section, and thickness of the neutron capture material. The isotope 10B is one of only a handful of isotopes with a high neutron absorption cross section---3840 barns for thermal neutrons. So a boron carbide semiconductor represents a viable alternative to 3He. This dissertation provides an evaluation of the performance of semiconducting boron carbide neutron detectors grown by plasma enhance chemical vapor deposition (PECVD) in order to determine the advantages and drawbacks of these devices for neutron detection. Improved handling of the PECVD system has resulted in an extremely stable plasma, enabling deposition of thick films of semiconducting boron carbide. A variety of material and semiconducting characterization tools have been used to investigate the structure and electronic properties of boron carbide thin films, including X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscopy, infrared/Raman spectroscopy, current-voltage measurements and capacitance-voltage measurements. Elemental concentrations in the boron carbide films have been obtained from Rutherford backscattering and elastic recoil detection analysis. Solid state neutron detection devices have been fabricated in the form of heterostructured p-n diodes, p-type boron carbide/n-type Si. Operating conditions, including applied bias voltage, and time constants, have been optimized for maximum detection efficiency and correlated to the semiconducting properties investigated in separate electronic measurements. Accurate measurements of the neutron detection efficiency and the response of the detector to a wide range of neutron wavelengths have been performed at a well calibrated, tightly collimated, "white" cold neutron beam source using time-of-flight neutron detection technique

  2. Quantitative evaluation of boron neutron capture therapy (BNCT) drugs for boron delivery and retention at subcellular scale resolution in human glioblastoma cells with imaging secondary ion mass spectrometry (SIMS)

    Science.gov (United States)

    Chandra, S.; Ahmad, T.; Barth, R. F.; Kabalka, G. W.

    2014-01-01

    Boron neutron capture therapy (BNCT) of cancer depends on the selective delivery of a sufficient number of boron-10 (10B) atoms to individual tumor cells. Cell killing results from the 10B (n, α)7Li neutron capture and fission reactions that occur if a sufficient number of 10B atoms are localized in the tumor cells. Intranuclear 10B localization enhances the efficiency of cell killing via damage to the DNA. The net cellular content of 10B atoms reflects both bound and free pools of boron in individual tumor cells. The assessment of these pools, delivered by a boron delivery agent, currently cannot be made at subcellular scale resolution by clinically applicable techniques such as PET and MRI. In this study, secondary ion mass spectrometry (SIMS) based imaging instrument, a CAMECA IMS 3f ion microscope, capable of 500 nm spatial resolution was employed. Cryogenically prepared cultured human T98G glioblastoma cells were evaluated for boron uptake and retention of two delivery agents. The first, L-p-boronophenylalanine (BPA), has been used clinically for BNCT of high grade gliomas, recurrent tumors of the head and neck region and melanomas. The second, a boron analogue of an unnatural amino acid, 1-amino-3-borono-cyclopentanecarboxylic acid (cis-ABCPC), has been studied in rodent glioma and melanoma models by quantification of boron in the nucleus and cytoplasm of individual tumor cells. The bound and free pools of boron were assessed by exposure of cells to boron-free nutrient medium. Both BPA and cis-ABCPC delivered almost 70% of the pool of boron in the free or loosely bound form to the nucleus and cytoplasm of human glioblastoma cells. This free pool of boron could be easily mobilized out of the cell and was in some sort of equilibrium with extracellular boron. In the case of BPA, the intracellular free pool of boron also was affected by the presence of phenylalanine in the nutrient medium. This suggests that it might be advantageous if patients were placed on a

  3. Quantitative evaluation of boron neutron capture therapy (BNCT) drugs for boron delivery and retention at subcellular-scale resolution in human glioblastoma cells with imaging secondary ion mass spectrometry (SIMS).

    Science.gov (United States)

    Chandra, S; Ahmad, T; Barth, R F; Kabalka, G W

    2014-06-01

    Boron neutron capture therapy (BNCT) of cancer depends on the selective delivery of a sufficient number of boron-10 ((10)B) atoms to individual tumour cells. Cell killing results from the (10)B (n, α)(7) Li neutron capture and fission reactions that occur if a sufficient number of (10)B atoms are localized in the tumour cells. Intranuclear (10)B localization enhances the efficiency of cell killing via damage to the DNA. The net cellular content of (10)B atoms reflects both bound and free pools of boron in individual tumour cells. The assessment of these pools, delivered by a boron delivery agent, currently cannot be made at subcellular-scale resolution by clinically applicable techniques such as positron emission tomography and magnetic resonance imaging. In this study, a secondary ion mass spectrometry based imaging instrument, a CAMECA IMS 3f ion microscope, capable of 500 nm spatial resolution was employed. Cryogenically prepared cultured human T98G glioblastoma cells were evaluated for boron uptake and retention of two delivery agents. The first, L-p-boronophenylalanine (BPA), has been used clinically for BNCT of high-grade gliomas, recurrent tumours of the head and neck region and melanomas. The second, a boron analogue of an unnatural amino acid, 1-amino-3-borono-cyclopentanecarboxylic acid (cis-ABCPC), has been studied in rodent glioma and melanoma models by quantification of boron in the nucleus and cytoplasm of individual tumour cells. The bound and free pools of boron were assessed by exposure of cells to boron-free nutrient medium. Both BPA and cis-ABCPC delivered almost 70% of the pool of boron in the free or loosely bound form to the nucleus and cytoplasm of human glioblastoma cells. This free pool of boron could be easily mobilized out of the cell and was in some sort of equilibrium with extracellular boron. In the case of BPA, the intracellular free pool of boron also was affected by the presence of phenylalanine in the nutrient medium. This

  4. Boron removal from hydraulic fracturing wastewater by aluminum and iron coagulation: Mechanisms and limitations.

    Science.gov (United States)

    Chorghe, Darpan; Sari, Mutiara Ayu; Chellam, Shankararaman

    2017-12-01

    One promising water management strategy during hydraulic fracturing is treatment and reuse of flowback/produced water. In particular, the saline flowback water contains many of the chemicals employed for fracking, which need to be removed before possible reuse as "frac water." This manuscript targets turbidity along with one of the additives; borate-based cross-linkers used to adjust the rheological characteristics of the frac-fluid. Alum and ferric chloride were evaluated as coagulants for clarification and boron removal from saline flowback water obtained from a well in the Eagle Ford shale. Extremely high dosages (> 9000 mg/L or 333 mM Al and 160 mM Fe) corresponding to Al/B and Fe/B mass ratios of ∼70 and molar ratios of ∼28 and 13 respectively were necessary to remove ∼80% boron. Hence, coagulation does not appear to be feasible for boron removal from high-strength waste streams. X-ray photoelectron spectroscopy revealed BO bonding on surfaces of freshly precipitated Al(OH) 3 (am) and Fe(OH) 3 (am) suggesting boron uptake was predominantly via ligand exchange. Attenuated total reflection-Fourier transform infrared spectroscopy provided direct evidence of inner-sphere boron complexation with surface hydroxyl groups on both amorphous aluminum and iron hydroxides. Only trigonal boron was detected on aluminum flocs since possible presence of tetrahedral boron was masked by severe AlO interferences. Both trigonal and tetrahedral conformation of boron complexes were identified on Fe(OH) 3 surfaces. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Boron neutron capture therapy for recurrent head and neck malignancies

    International Nuclear Information System (INIS)

    Kato, Itsuro; Ono, Koji; Ohmae, Masatoshi

    2005-01-01

    Boron neutron capture therapy (BNCT) is a tumor-cell targeted radiotherapy. When 10 B absorbs thermal neutrons, the alpha and 7 Li particles generated by the 10 B (n, α) 7 Li reaction are high linear energy transfer (LET) particles, and carry high kinetic energy (2.34 MeV), and have short ranges (4-9 micron-meters) of approximately one-cell diameter, resulting in a large relative biological effectiveness (RBE) and selective destruction of tumor cells containing 10 B. We have, for the first time in the world, used BNCT to treat 11 patients with recurrent head and neck malignancies (HNM) after a standard primary therapy since 2001. The 11 patients were composed of 6 squamous cell carcinomas, 3 salivary gland tumors and 2 sarcomas. The results of BNCT were as follows. Regression rates (volume %) were complete response (CR): 2 cases, >90%: 5 cases, 73%: 1 case, 54%: 1 case, progressive disease (PD): 1 case, NE (not evaluated): 1 case. The response rate was 82%. Improvement of quality of life (QOL) was recognized, such as disappearance of tumor ulceration and covering with normal skin: relief of severe pain, bleeding, trismus and dyspnea: improvement of performance status (PS) (from 4 to 2) allowing the patients to return to work and elongate his survival period. Survival periods after BNCT were 1-38 months (mean: 8.5 months). The survival rate was 36% (4 cases). There are a few side-effects such as transient mucositis and alopecia less than Grade-2. These results indicate that BNCT represents a new and promising treatment approach even for a huge or far-advanced HNM. (author)

  6. Targeting triple negative breast cancer cells by N3-substituted 9,10-phenanthrenequinone thiosemicarbazones and their metal complexes.

    Science.gov (United States)

    Afrasiabi, Zahra; Stovall, Preston; Finley, Kristen; Choudhury, Amitava; Barnes, Charles; Ahmad, Aamir; Sarkar, Fazlul; Vyas, Alok; Padhye, Subhash

    2013-10-01

    Novel N(3)-substituted 9,10-Phenanthrenequinone thiosemicarbazones and their copper, nickel and palladium complexes are structurally characterized and reported along with the single crystal X-ray structures of three ligands and one nickel complex. All compounds were evaluated for their antiproliferative potential against Triple Negative Breast Cancer (TNBC) cells which have poor prognosis and no effective drugs to treat with. All compounds exhibited antiproliferative activity against these cells. Among the metal complexes evaluated, redox active copper complexes were found to be more potent. The possible mechanism for such enhanced activity can be attributed to the generation of oxidative stress, which was amenable for targeting through metal complexation. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Improved tribological behavior of boron implanted Ti-6Al-4V

    International Nuclear Information System (INIS)

    Baker, N.P.; Walter, K.C.; Nastasi, M.

    1998-03-01

    Boron implanted of Ti6Al4V has been conducted at combinations of 32 and 40 keV to supplement that done previously at 75 keV. Shallower boron depth profiles with higher B-concentrations in the Ti64 surface have been obtained by tailoring the combinations of ion energy and dose. This work used three different ion energy and dose combinations of 4 x 10 17 B-at/cm 2 at 40 keV plus 2 x 10 17 B-at/cm 2 at 32 keV, 4 x 10 17 B-at/cm 2 at 40 keV, and 4 x 10 17 B-at/cm 2 at 32 keV plus 2 x 10 17 B-at/cm 2 at 40 keV. Comparisons are made between Ti6Al4V with a shallow implanted boron depth profile, Ti6Al4V with a deeper boron depth profile and nitrogen implanted using a plasma source ion implantation process. It has been previously shown that while boron implanted Ti64 has a ∼ 30% higher surface hardness than nitrogen implanted Ti64, the N-implantation reduced the wear coefficient of Ti64 by 25--120x, while B-implantation reduced the wear coefficient by 6.5x or less. The results show that no significant improvement is made in the wear resistance of boron implanted Ti6Al4V by increasing the concentration of boron at the surface from approximately 10% to 43%. Transmission electron microscopy (TEM) and selected area diffraction (SAD) indicated the formation of crystalline TiB in the implanted surface layer. Shallower depth profiles result in reductions of the Ti6Al4V wear coefficient by 6.5x or less which is the same result obtained earlier with the deeper boron depth profile. Surface hardness of Ti6Al4V with shallower boron depth profiles was improved approximately 10% compared to the results previously acquired with deeper boron depth profiles

  8. XPS study of the process of oxygen gettering by thin films of PACVD boron

    Science.gov (United States)

    Ennaceur^1, M. M.; Terreault, B.

    2000-06-01

    Numerous collector samples have been exposed in the TdeV tokamak, either to plasma assisted chemical vapor boronization only, or to boronization plus tokamak power discharges. They have been analyzed by X-ray photoelectron spectroscopy (XPS) in order to characterize and better understand the process by which the boron-rich film getter ambient oxygen. It was found that the state of oxidation of the samples after boronization is the most reliable predictor of subsequent machine performance. The gettering capacity is high, on the order of 10 21 O/m 2, and affects a surprisingly thick layer (˜100 nm), but the oxide always remains substoichiometric (with a formula BO x, x < 1). The oxidation is clearly activated by the plasma, during both glow discharge deposition and power discharges, but in this respect the latter are much more effective than the former.

  9. In vitro biological efficacy of boronated low density lipoproteins for NCT

    International Nuclear Information System (INIS)

    Kahl, S.B.; Pate, D.; Laster, B.H.; Popenoe, E.A.; Fairchild, R.G.

    1992-01-01

    Low Density Lipoproteins (LDLs) are known to be internalized within the cell by receptor-mediated mechanisms. There is evidence that LDLs may be taken up avidly by tumor cells to provide cholesterol for the synthesis of cell membrane. Thus, the possibility exists that LDLs may provide an ideal vehicle for the transport of boron to tumor cells for Neutron Capture Therapy (NCT). A boronated analog of LDL has recently been synthesized for possible application in NCT. The analog was tested in cell culture for uptake and biological efficacy in the thermal neutron beam at the Brookhaven Medical Research Reactor (BMRR). It was found that boron concentrations ten times higher than that required for NCT were easily obtained, and that uptake data were constant with a receptor mediated binding mechanism. The measured intracellular concentration of ∼240 μg 10 B/g cells is significantly higher than that obtained with any other boron compound previously evaluated for possible clinical application

  10. Electrochemical Performance and Stability of the Cathode for Solid Oxide Fuel Cells: III. Role of volatile boron species on LSM/YSZ and LSCF

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xiao Dong; Templeton, Jared W.; Zhu, Zihua; Chou, Y. S.; Maupin, Gary D.; Lu, Zigui; Brow, R. K.; Stevenson, Jeffry W.

    2010-09-02

    Boron oxide is a key component to tailor the softening temperature and viscosity of the sealing glass for solid oxide fuel cells. The primary concern regarding the use of boron containing sealing glasses is the volatility of boron species, which possibly results in cathode degradation. In this paper, we report the role of volatile boron species on the electrochemical performance of LSM/YSZ and LSCF cathodes at various SOFC operation temperatures. The transport rate of boron, ~ 3.24×10-12 g/cm2•sec was measured at 750°C with air saturated with 2.8% moisture. A reduction in power density was observed in cells with LSM/YSZ cathodes after introduction of the boron source to the cathode air stream. Partial recovery of the power density was observed after the boron source was removed. Results from post-test secondary ion mass spectroscopy (SIMS) analysis the partial recovery in power density correlated with partil removal of the deposited boron by the clean air stream. The presence of boron was also observed in LSCF cathodes by SIMS analysis, however the effect of boron on the electrochemical performance of LSCF cathode was negligible. Coverage of triple phase boundaries in LSM/YSZ was postulated as the cause for the observed reduction in electrochemical performance.

  11. Evaluation of177Lu-CHX-A″-DTPA-6A10 Fab as a radioimmunotherapy agent targeting carbonic anhydrase XII.

    Science.gov (United States)

    Fiedler, L; Kellner, M; Gosewisch, A; Oos, R; Böning, G; Lindner, S; Albert, N; Bartenstein, P; Reulen, H-J; Zeidler, R; Gildehaus, F J

    2018-03-04

    Due to their infiltrative growth behavior, gliomas have, even after surgical resection, a high recurrence tendency. The approach of intracavitary radioimmunotherapy (RIT) is aimed at inhibiting tumor re-growth by directly administering drugs into the resection cavity (RC). Direct application of the radioconjugate into the RC has the advantage of bypassing the blood-brain barrier, which allows the administration of higher radiation doses than systemic application. Carbonic anhydrase XII (CA XII) is highly expressed on glioma cells while being absent from normal brain and thus an attractive target molecule for RIT. We evaluated a CA XII-specific 6A10 Fab (fragment antigen binding) labelled with 177 Lu as an agent for RIT. 6A10 Fab fragment was modified and radiolabelled with 177 Lu and characterized by MALDI-TOF, flow cytometry and radio-TLC. In vitro stability was determined under physiological conditions. Biodistribution studies, autoradiography tumor examinations and planar scintigraphy imaging were performed on SCID-mice bearing human glioma xenografts. The in vitro CA XII binding capacity of the modified Fab was confirmed. Radiochemical purity was determined to be >90% after 72 h of incubation under physiological conditions. Autoradiography experiments proved the specific binding of the Fab to CA XII on tumor cells. Biodistribution studies revealed a tumor uptake of 3.0%ID/g after 6 h and no detectable brain uptake. The tumor-to-contralateral ratio of 10/1 was confirmed by quantitative planar scintigraphy. The radiochemical stability in combination with a successful in vivo tumor uptake shows the potential suitability for future RIT applications with the 6A10 Fab. Copyright © 2018. Published by Elsevier Inc.

  12. Neutron irradiation effects on spark plasma sintered boron carbide

    International Nuclear Information System (INIS)

    Buyuk, B.; Cengiz, M.; Tugrul, A.; Ozer, S.; Yucel, O.; Goller, G.; Sahin, F.C.; Lastovski, S.B.

    2015-01-01

    In this study, spark plasma sintered boron carbide (B 4 C) was examined against neutrons. The specimens were ir-radiated by reactor neutrons (include both thermal and fast neutrons) up to fluence of 1.37x10 21 n*m -2 . Thermal and fast neutrons cause swelling by different interactions with boron ( 10 B) atoms in the related materials. X-Ray diffraction (XRD) patterns and scanning electron microscopy (SEM) images were investigated for initial and irradiated samples. In addition, lattice parameters and unit cell volumes were calculated for the samples. The swelling percentages were calculated to be within a range of 0.49-3.80 % (average 1.70 %) for the outer surface of the materials for applied neutron irradiation doses. (authors)

  13. Nuclear Physics meets Medicine and Biology: Boron Neutron Capture Therapy

    CERN Document Server

    F. Ballarini, F; S. Bortolussi, S; P. Bruschi, P; A.M. Clerici, A M; A. De Bari, A; P. Dionigi, P; C. Ferrari, C; M.A. Gadan, M A; N. Protti, N; S. Stella, S; C. Zonta, C; A. Zonta, A; S. Altieri, S

    2010-01-01

    BNCT is a tumour treatment based on thermal-neutron irradiation of tissues enriched with 10B, which according to the 10B(n, )7Li reaction produces particles with high Linear Energy Transfer and short range. Since this treatment can deliver a therapeutic tumour dose sparing normal tissues, BNCT represents an alternative for diffuse tumours and metastases, which show poor response to surgery and photontherapy. In 2001 and 2003, in Pavia BNCT was applied to an isolated liver, which was infused with boron, explanted, irradiated and re-implanted. A new project was then initiated for lung tumours, developing a protocol for Boron concentration measurements and performing organ-dose Monte Carlo calculations; in parallel, radiobiology studies are ongoing to characterize the BNCT effects down to cellular level. After a brief introduction, herein we will present the main activities ongoing in Pavia including the radiobiological ones, which are under investigation not only experimentally but also theoretically, basing on...

  14. Target studies for surface muon production

    Directory of Open Access Journals (Sweden)

    F. Berg

    2016-02-01

    Full Text Available Meson factories are powerful drivers of diverse physics programs. With beam powers already in the MW-regime attention has to be turned to target and beam line design to further significantly increase surface muon rates available for experiments. For this reason we have explored the possibility of using a neutron spallation target as a source of surface muons by performing detailed Geant4 simulations with pion production cross sections based on a parametrization of existing data. While the spallation target outperforms standard targets in the backward direction by more than a factor 7 it is not more efficient than standard targets viewed under 90°. Not surprisingly, the geometry of the target plays a large role in the generation of surface muons. Through careful optimization, a gain in surface muon rate of between 30% and 60% over the standard “box-like” target used at the Paul Scherrer Institute could be achieved by employing a rotated slab target. An additional 10% gain could also be possible by utilizing novel target materials such as, e.g., boron carbide.

  15. Radio response of human lymphocytes pretreated with boron and gadoliniums assessed by the, comet assay

    International Nuclear Information System (INIS)

    Kim, J. K.; Park, T. W.; Cebulska-Wasiewska, A.; Nili, M.

    2009-01-01

    Boron and gadolinium are among the nuclides that hold a unique property of being a neutron capture therapy agent. Neutron beams have often a considerable portion of gamma rays with fast neutrons. Gamma rays, as beam contaminants, can cause considerable damage to normal tissues even if such tissues do contain high boron concentrations. Materials and Methods: The modification of radio response in human lymphocytes pretreated with boron or gadolinium compound was studied by assessing the DNA damage using single cell gel electrophoresis, the comet assay. The lymphocytes from the human peripheral blood were irradiated with 0, 1, 2 and 4 Gy of gamma rays from a 60 Co isotopic source with or without pretreatment of boron or gadolinium compound for 10 minutes at 4 d egree C . Post-irradiation procedures included slide preparation, cell-lysing, unwinding and electrophoresis, neutralization, staining, and analytic steps, gel electrophoresis. Results: The results indicate that pretreatment with boron compound (50 n M or 250 n M of 10 B) is effective in reducing the radiosensitivity of the lymphocyte DNA. Conversely, pretreatment with gadolinium compound (50 n M) led to a dose-dependent increase in the radiosensitivity, most prominently with a dose of 4 Gy (P<0.001). Furthermore, when the lymphocytes were pretreated with a Combined mixture (1:1) of boron (250 n M) and gadolinium (50 n M) compounds, the reduced radiosensitivity was also observed.

  16. Sodium borocaptate (BSH) for Boron Neutron Capture Therapy (BNCT) in the hamster cheek pouch oral cancer model: boron biodistribution at 9 post administration time-points

    International Nuclear Information System (INIS)

    Garabalino, M.A.; Heber, E.M.; Monti, Hughes A.; Molinari, A.J.; Pozzi, E.C.C.; Trivillin, V.A.; Schwint, Amanda E.

    2011-01-01

    The therapeutic success of Boron Neutron Capture Therapy (BNCT) depends centrally on boron concentration in tumor and healthy tissue. We previously demonstrated the therapeutic efficacy of boronophenylalanine (BPA) and sodium decahydrodecaborate (GB-10) as boron carriers for BNCT in the hamster cheek pouch oral cancer model. Given the clinical relevance of sodium mercaptoundecahydro-closo-dodecaborate (BSH) as a boron carrier, the aim of the present study was to expand the ongoing BSH biodistribution studies in the hamster cheek pouch oral cancer model. In particular, we studied 3 additional post-administration time-points and increased the sample size corresponding to the time-points evaluated previously, to select more accurately the post-administration time at which neutron irradiation would potentially confer the greatest therapeutic advantage. BSH was dissolved in saline solution in anaerobic conditions to avoid the formation of the dimer BSSB and its oxides which are toxic. The solution was injected intravenously at a dose of 50 mg 10 B/kg (88 mg BSH / kg). Different groups of animals were killed humanely at 7, 8, and 10 h after administration of BSH. The sample size corresponding to the time-points 3, 4, 6, 9 and 12 h was increased. Samples of blood, tumor, precancerous tissue, normal pouch tissue, cheek mucosa, parotid gland, palate, skin, tongue, spinal cord marrow, brain, liver, kidney, spleen and lung were processed for boron measurement by Optic Emission Spectroscopy (ICP-OES). Boron concentration in tumor peaked to 24-34 ppm, 3-10 h post-administration of BSH, with a spread in values that resembled that previously reported in other experimental models and human subjects. The boron concentration ratios tumor/normal pouch tissue and tumor/blood ranged from 1.3 to 1.8. No selective tumor uptake was observed at any of the time points evaluated. The times post-administration of BSH that would be therapeutically most useful would be 5, 7 and 9 h. The

  17. Effects of application boron on yields, yield component and oil ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-08-18

    Aug 18, 2008 ... The study was conducted to investigate the effects of five boron (B) doses; 0, 2.5, 5.0, 7.5 and 10.0 kg B ha-1 in B-deficient calcareous soils on yield and some yield components of four sunflower genotypes. Genotypes have shown variations with respect to their responses to B applications. AS-615 and ...

  18. Effects of application boron on yields, yield component and oil ...

    African Journals Online (AJOL)

    The study was conducted to investigate the effects of five boron (B) doses; 0, 2.5, 5.0, 7.5 and 10.0 kg B ha-1 in B-deficient calcareous soils on yield and some yield components of four sunflower genotypes. Genotypes have shown variations with respect to their responses to B applications. AS-615 and Coban had the ...

  19. Separation of the isotopes of boron by chemical exchange reactions

    Science.gov (United States)

    McCandless, F.P.; Herbst, R.S.

    1995-05-30

    The isotopes of boron, {sup 10}B and {sup 11}B, are separated by means of a gas-liquid chemical exchange reaction involving the isotopic equilibrium between gaseous BF{sub 3} and a liquid BF{sub 3} donor molecular addition complex formed between BF{sub 3} gas and a donor chosen from the group consisting of: nitromethane, acetone, methyl isobutyl ketone, or diisobutyl ketone. 1 Fig.

  20. Separation of the isotopes of boron by chemical exchange reactions

    Science.gov (United States)

    McCandless, Frank P.; Herbst, Ronald S.

    1995-01-01

    The isotopes of boron, .sup.10 B and .sup.11 B, are separated by means of a gas-liquid chemical exchange reaction involving the isotopic equilibrium between gaseous BF.sub.3 and a liquid BF.sub.3 . donor molecular addition complex formed between BF.sub.3 gas and a donor chosen from the group consisting of: nitromethane, acetone, methyl isobutyl ketone, or diisobutyl ketone.

  1. Development of particle induced gamma-ray emission methods for nondestructive determination of isotopic composition of boron and its total concentration in natural and enriched samples.

    Science.gov (United States)

    Chhillar, Sumit; Acharya, Raghunath; Sodaye, Suparna; Pujari, Pradeep K

    2014-11-18

    We report simple particle induced gamma-ray emission (PIGE) methods using a 4 MeV proton beam for simultaneous and nondestructive determination of the isotopic composition of boron ((10)B/(11)B atom ratio) and total boron concentrations in various solid samples with natural isotopic composition and enriched with (10)B. It involves measurement of prompt gamma-rays at 429, 718, and 2125 keV from (10)B(p,αγ)(7)Be, (10)B(p, p'γ)(10)B, and (11)B(p, p'γ)(11)B reactions, respectively. The isotopic composition of boron in natural and enriched samples was determined by comparing peak area ratios corresponding to (10)B and (11)B of samples to natural boric acid standard. An in situ current normalized PIGE method, using F or Al, was standardized for total B concentration determination. The methods were validated by analyzing stoichiometric boron compounds and applied to samples such as boron carbide, boric acid, carborane, and borosilicate glass. Isotopic compositions of boron in the range of 0.247-2.0 corresponding to (10)B in the range of 19.8-67.0 atom % and total B concentrations in the range of 5-78 wt % were determined. It has been demonstrated that PIGE offers a simple and alternate method for total boron as well as isotopic composition determination in boron based solid samples, including neutron absorbers that are important in nuclear technology.

  2. Boron carbide synthesis by carbothermic reduction of boron oxide

    International Nuclear Information System (INIS)

    Castro, A.R.M. de; Paschoal, J.O.A.

    1988-01-01

    Boron carbide (B 4 C) is a ceramic material of technological applications due to its extreme hardness and high chemical as well as thermal stability. Some parameters of the process for obtaining B 4 C by carbothermic reduction of B 2 O 3 have been determined. The starting powders and the final products have been analysed by chemical, spectrographic and X-ray diffraction methods. The results show that the B 4 C obtained by the carbothermic reduction process is suitable for applications with a definite determination of the free carbon content. (author) [pt

  3. Targeting of Mitochondria by 10-N-Alkyl Acridine Orange Analogues: Role of Alkyl Chain Length in Determining Cellular Uptake and Localization

    Science.gov (United States)

    Rodriguez, Myriam E.; Azizuddin, Kashif; Zhang, Ping; Chiu, Song-mao; Lam, Minh; Kenney, Malcolm E.; Burda, Clemens; Oleinick, Nancy L.

    2008-01-01

    10-N-nonyl acridine orange (NAO) is used as a mitochondrial probe because of its high affinity for cardiolipin (CL). Targeting of NAO may also depend on mitochondrial membrane potential. As the nonyl group has been considered essential for targeting, a systematic study of alkyl chain length was undertaken; three analogues (10-methyl-, 10-hexyl-, and 10-hexadecyl-acridine orange) were synthesized and their properties studied in phospholipid monolayers and breast cancer cells. The shortest and longest alkyl chains reduced targeting, whereas the hexyl group was superior to the nonyl group, allowing very clear and specific targeting to mitochondria at concentrations of 20–100 nM, where no evidence of toxicity was apparent. Additional studies in wild-type and cardiolipin-deficient yeast cells suggested that cellular binding was not absolutely dependent upon cardiolipin. PMID:18514589

  4. Carborane derivative development for boron neutron capture therapy. Final report

    International Nuclear Information System (INIS)

    Barnum, Beverly A.; Yan Hao; Moore, Roger; Hawthorne, M. Frederick; Baum, Kurt

    1999-01-01

    Boron Neutron Capture Therapy [BNCT] is a binary method of cancer therapy based on the capture of neutrons by a boron-10 atom [ 10 B]. Cytotoxic 7 Li nuclei and α-particles are emitted, with a range in tissue of 9 and 5 microm, respectively, about one cell diameter. The major obstacle to clinically viable BNCT is the selective localization of 5-30 ppm 10 B in tumor cells required for effective therapy. A promising approach to BNCT is based on hydrophilic boron-rich oligomeric phosphate diesters, or ''trailers'' that have been shown to concentrate selectively in tumor tissue. Examples of these compounds were prepared previously at high cost using an automated DNA synthesizer. Direct synthesis methods are needed for the production of gram-scale quantities for further biological evaluation. The work accomplished as a result of the collaboration between Fluorochem, Inc. and UCLA demonstrates that short oligomers containing at least five carborane units with four phosphodiester linkages can be prepared in substantial quantities. This work was accomplished by the application of standard phosphoramidite coupling chemistry

  5. Boron Carbides As Thermo-electric Materials

    Science.gov (United States)

    Wood, Charles

    1988-01-01

    Report reviews recent theoretical and experimental research on thermoelectric materials. Recent work with narrow-band semiconductors demonstrated possibility of relatively high thermoelectric energy-conversion efficiencies in materials withstanding high temperatures needed to attain such efficiencies. Among promising semiconductors are boron-rich borides, especially boron carbides.

  6. Boron carbide whiskers produced by vapor deposition

    Science.gov (United States)

    1965-01-01

    Boron carbide whiskers have an excellent combination of properties for use as a reinforcement material. They are produced by vaporizing boron carbide powder and condensing the vapors on a substrate. Certain catalysts promote the growth rate and size of the whiskers.

  7. Compression and associated properties of boron carbide

    Science.gov (United States)

    Ciezak, Jennifer; Dandekar, Dattatraya

    2009-06-01

    The observed loss of shear strength of boron carbide around 22 GPa has been attributed to presence of amorphous material in the shock recovered, and statically indented and pressurized boron carbide. The present work presents a more direct association of the observed loss of shear strength in boron carbide under plane shock wave compression to amorphization in boron carbide under triaxial stress compression. This evidence is obtained from in-situ measurement of Raman, and infrared vibrational spectra of boron carbide confined in a Diamond Anvil Cell (DAC) under hydrostatic and non-hydrostatic pressures. X-ray-diffraction measurements do show a shift in the compression of boron carbide around 27 GPa. However, X-ray diffraction measurements indicate that the amorphization does not extend to micron scale, as there is no evidence of a loss of crystallinity in the recorded diffraction pattern of boron carbide to 47 GPa. Our work shows that shear plays a very dominant role in the stress-induced amorphization of boron carbide.

  8. Ultratough single crystal boron-doped diamond

    Science.gov (United States)

    Hemley, Russell J [Carnegie Inst. for Science, Washington, DC ; Mao, Ho-Kwang [Carnegie Inst. for Science, Washington, DC ; Yan, Chih-Shiue [Carnegie Inst. for Science, Washington, DC ; Liang, Qi [Carnegie Inst. for Science, Washington, DC

    2015-05-05

    The invention relates to a single crystal boron doped CVD diamond that has a toughness of at least about 22 MPa m.sup.1/2. The invention further relates to a method of manufacturing single crystal boron doped CVD diamond. The growth rate of the diamond can be from about 20-100 .mu.m/h.

  9. Spectral tailoring for boron Neutron capture therapy

    NARCIS (Netherlands)

    Nievaart, V.A.

    2007-01-01

    In several places in the world, such as Petten and Delft in the Netherlands, investigations are in progress in the fight against certain types of cancer with Boron Neutron Capture Therapy. The basic idea is very simple: boron is loaded only into the cancer cells, using a special drug, after which

  10. Fabrication of boron-phosphide neutron detectors

    International Nuclear Information System (INIS)

    Fitzsimmons, M.; Pynn, R.

    1997-01-01

    Boron phosphide is a potentially viable candidate for high neutron flux neutron detectors. The authors have explored chemical vapor deposition methods to produce such detectors and have not been able to produce good boron phosphide coatings on silicon carbide substrates. However, semi-conducting quality films have been produced. Further testing is required

  11. Possible toxicity of boron on sugar cane

    Energy Technology Data Exchange (ETDEWEB)

    Bravo C., M.

    Analyses of necrotic and green leaf tissues from sugar cane grown in the Tambo Valley (Arequipa, Peru) have shown that the boron concentration in necrotic tissue (average 657.7 ppm) is several times higher than that in the green tissue (average 55.7 ppm). This suggests that the necrosis may be due to boron toxicity.

  12. Electrophoretic deposits of boron on duralumin plates used for measuring neutron flux; Depots electrophoretiques de bore sur plaques de duralumin destines a des mesures de flux de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Lang, F.M.; Magnier, P.; Finck, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1956-07-01

    Preparation of boron thin film deposits of around 1 mg per cm{sup 2} on duralumin plates with a diameter of 8 cm. The boron coated plates for ionization chambers were originally prepared at the CEA by pulverization of boron carbides on sodium silicates. This method is not controlling precisely enough the quantity of boron deposit. Thus, an electrophoretic method is considered for a better control of the quantity of boron deposit in the scope of using in the future boron 10 which is costly and rare. The method described by O. Flint is not satisfying enough and a similar electrophoretic process has been developed. Full description of the method is given as well as explanation of the use of dried methanol as solvent, tannin as electrolyte and magnesium chloride to avoid alumina formation. (M.P.)

  13. Studi Awal Pengaruh Pemberian Asam Boron dan Penembakan Neutron terhadap cell fibroblast dan cell lineKanker Payudara

    Directory of Open Access Journals (Sweden)

    Giner Maslebu

    2017-11-01

    Full Text Available Kanker merupakan salah satu penyakit mematikan yang mendapatkan perhatian serius oleh peneliti dan praktisi di bidang kesehatan. Penyakit kanker adalah penyakit yang timbul akibat pertumbuhan tidak normal sel jaringan tubuh yang berubah menjadi sel kanker.Dari berbagai jenis kanker, kasus yang paling banyak terjadi pada kaum perempuan adalah kanker payudara. Teknik pengobatan kanker terus dikembangkan sehingga mampu secara selektif membunuh target sel kanker (cell targeting dan memberikan efek yang minimal bagi sel sehat di sekitar target. Salah satu teknik pengobatan yang menjanjikan adalah Boron Neutron Captured Teraphy (BNCT. Dalam penelitian ini, sel fibroblast dan sel kanker payudara T47D dipanen pada sumuran setelah diinkubasi selama 16 jam, kemudian diberikan perlakuan  asam boron dengan dosis asam boron berjenjang 100 µM, 200 µM, 400 µM.Penembakan neutron diberikan dengan flux sebesar 1010 neutron/cm2s mengggunakan sumber neutron pada fasilitas reaktor Kartini PSTA-Batan terhadap kultur selselama 30 menit. Pada sel fibroblast tingkat kematian sel berkisar antara 2,5-21,212 % setelah pemberian asam Boron dan meningkat menjadi 24,242-71,424 % setelah penembakan neutron. Pada sel kanker payudara T47D tingkat kematian sel berkisar antara 26,761-48,76 % setelah pemberian asam Boron dan meningkat menjadi 36,585-56,25 % setelah penembakan neutron. Hasil penelitian ini menunjukkan ada pengaruh pemberian asam Boron dan penembakan Neutron terhadap tingkat kematian sel.

  14. Termite Resistance of MDF Panels Treated with Various Boron Compounds

    Directory of Open Access Journals (Sweden)

    Sedat Ondaral

    2009-06-01

    Full Text Available In this study, the effects of various boron compounds on the termite resistance of MDF panels were evaluated. Either borax (BX, boric acid (BA, zinc borate (ZB, or sodium perborate tetrahydrate (SPT were added to urea-formaldehyde (UF resin at target contents of 1%, 1.5%, 2% and 2.5% based on dry fiber weight. The panels were then manufactured using 12% urea-formaldehyde resin and 1% NH4Cl. MDF samples from the panels were tested against the subterranean termites, Coptotermes formosanus Shiraki. Laboratory termite resistance tests showed that all samples containing boron compounds had greater resistance against termite attack compared to untreated MDF samples. At the second and third weeks of exposure, nearly 100% termite mortalities were recorded in all boron compound treated samples. The highest termite mortalities were determined in the samples with either BA or BX. Also, it was found that SPT showed notable performance on the termite mortality. As chemical loadings increased, termite mortalities increased, and at the same time the weight losses of the samples decreased.

  15. XPS analysis of boron doped heterofullerenes

    Energy Technology Data Exchange (ETDEWEB)

    Schnyder, B.; Koetz, R. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Muhr, H.J.; Nesper, R. [ETH Zurich, Zurich (Switzerland)

    1997-06-01

    Boron heterofullerenes were generated through arc-evaporation of doped graphite rods in a helium atmosphere. According to mass spectrometric analysis only mono-substituted fullerenes like C{sub 59}B, C{sub 69}B and higher homologues together with a large fraction of higher undoped fullerenes were extracted and enriched when pyridine was used as the solvent. XPS analysis of the extracts indicated the presence of two boron species with significantly different binding energies. One peak was assigned to borid acid. The second one corresponds to boron in the fullerene cage, which is mainly C{sub 59}B, according to the mass spectrum. This boron is in a somewhat higher oxidation state than that of ordinary boron-carbon compounds. The reported synthesis and extraction procedure opens a viable route for production of macroscopic amounts of these compounds. (author) 2 figs., 1 tab., 7 refs.

  16. Continuum modeling of boron nitride nanotubes

    International Nuclear Information System (INIS)

    Song, J; Wu, J; Hwang, K C; Huang, Y

    2008-01-01

    Boron nitride nanotubes display unique properties and have many potential applications. A finite-deformation shell theory is developed for boron nitride nanotubes directly from the interatomic potential to account for the effect of bending and curvature. Its constitutive relation accounts for the nonlinear, multi-body atomistic interactions, and therefore can model the important effect of tube chirality and radius. The theory is then used to determine whether a single-wall boron nitride nanotube can be modeled as a linear elastic isotropic shell. Instabilities of boron nitride nanotubes under different loadings (e.g., tension, compression, and torsion) are also studied. It is shown that the tension instability of boron nitride nanotubes is material instability, while the compression and torsion instabilities are structural instabilities.

  17. Stabilization of boron carbide via silicon doping.

    Science.gov (United States)

    Proctor, J E; Bhakhri, V; Hao, R; Prior, T J; Scheler, T; Gregoryanz, E; Chhowalla, M; Giulani, F

    2015-01-14

    Boron carbide is one of the lightest and hardest ceramics, but its applications are limited by its poor stability against a partial phase separation into separate boron and carbon. Phase separation is observed under high non-hydrostatic stress (both static and dynamic), resulting in amorphization. The phase separation is thought to occur in just one of the many naturally occurring polytypes in the material, and this raises the possibility of doping the boron carbide to eliminate this polytype. In this work, we have synthesized boron carbide doped with silicon. We have conducted a series of characterizations (transmission electron microscopy, scanning electron microscopy, Raman spectroscopy and x-ray diffraction) on pure and silicon-doped boron carbide following static compression to 50 GPa non-hydrostatic pressure. We find that the level of amorphization under static non-hydrostatic pressure is drastically reduced by the silicon doping.

  18. Boron isotopes in the Seine River, France: a probe of anthropogenic contamination.

    Science.gov (United States)

    Chetelat, Benjamin; Gaillardet, Jérôme

    2005-04-15

    Boron concentrations and isotopic compositions have been measured in the dissolved load of the Seine Basin rivers, France. Hydrology and chemistry of the Seine River and its tributaries are strongly influenced by human activities, as the anthropogenic pressure on the Seine catchment is one of the highest in Europe. The samples were collected between 1994 and 1996 during various stages of flow, complemented by a time-series of the Seine River in Paris for 1 yr. In particular, the decennial flood event of winter 1994 was sampled. Boron appears to be conservative in rivers and not influenced by adsorption onto suspended matter and/or consumption by microorganisms. Despite the complexity of the Seine River system, dissolved boron and its isotopes are found to be suitable tracers of contamination. The total dissolved boron of the Seine River at Paris is explained by the contribution from three distinct components: Urban effluents constitute 65% of the boron discharge measured in the Seine River whereas agriculture-affected waters contribute less than 10% with a more marked influence during high water discharges. Rainwater contribution is important (25% mean), reaching 30% of dissolved boron during high flood events.

  19. Effect of Boron on Thymic Cytokine Expression, Hormone Secretion, Antioxidant Functions, Cell Proliferation, and Apoptosis Potential via the Extracellular Signal-Regulated Kinases 1 and 2 Signaling Pathway.

    Science.gov (United States)

    Jin, Erhui; Ren, Man; Liu, Wenwen; Liang, Shuang; Hu, Qianqian; Gu, Youfang; Li, Shenghe

    2017-12-27

    Boron is an essential trace element in animals. Appropriate boron supplementation can promote thymus development; however, a high dose of boron can lead to adverse effects and cause toxicity. The influencing mechanism of boron on the animal body remains unclear. In this study, we examined the effect of boron on cytokine expression, thymosin and thymopoietin secretion, antioxidant function, cell proliferation and apoptosis, and extracellular signal-regulated kinases 1 and 2 (ERK1/2) pathway in the thymus of rats. We found that supplementation with 10 and 20 mg/L boron to the drinking water significantly elevated levels of interleukin 2 (IL-2), interferon γ (IFN-γ), interleukin 4 (IL-4), and thymosin α1 in the thymus of rats (p boron had no apparent effect on many of the above indicators. In contrast, supplementation with 480 and 640 mg/L boron had the opposite effect on the above indicators in rats and elevated levels of pro-inflammatory cytokines, such as interleukin 6 (IL-6), interleukin 1β (IL-1β), and tumor necrosis factor α (TNF-α) (p boron to the drinking water had a U-shaped dose-effect relationship with thymic cytokine expression, hormone secretion, antioxidant function, cell proliferation, and apoptosis. Specifically, supplementation with 10 and 20 mg/L boron promoted thymocyte proliferation and enhanced thymic functions. However, supplementation with 480 and 640 mg/L boron inhibited thymic functions and increased the number of apoptotic thymocytes, suggesting that the effects of boron on thymic functions may be caused via the ERK1/2 signaling pathway.

  20. Nanopores creation in boron and nitrogen doped polycrystalline graphene: A molecular dynamics study

    Science.gov (United States)

    Izadifar, Mohammadreza; Abadi, Rouzbeh; Nezhad Shirazi, Ali Hossein; Alajlan, Naif; Rabczuk, Timon

    2018-05-01

    In the present paper, molecular dynamic simulations have been conducted to investigate the nanopores creation on 10% of boron and nitrogen doped polycrystalline graphene by silicon and diamond nanoclusters. Two types of nanoclusters based on silicon and diamond are used to investigate their effect for the fabrication of nanopores. Therefore, three different diameter sizes of the clusters with five kinetic energies of 10, 50, 100, 300 and 500 eV/atom at four different locations in boron or nitrogen doped polycrystalline graphene nanosheets have been perused. We also study the effect of 3% and 6% of boron doped polycrystalline graphene with the best outcome from 10% of doping. Our results reveal that the diamond cluster with diameter of 2 and 2.5 nm fabricates the largest nanopore areas on boron and nitrogen doped polycrystalline graphene, respectively. Furthermore, the kinetic energies of 10 and 50 eV/atom can not fabricate nanopores in some cases for silicon and diamond clusters on boron doped polycrystalline graphene nanosheets. On the other hand, silicon and diamond clusters fabricate nanopores for all locations and all tested energies on nitrogen doped polycrystalline graphene. The area sizes of nanopores fabricated by silicon and diamond clusters with diameter of 2 and 2.5 nm are close to the actual area size of the related clusters for the kinetic energy of 300 eV/atom in all locations on boron doped polycrystalline graphene. The maximum area and the average maximum area of nanopores are fabricated by the kinetic energy of 500 eV/atom inside the grain boundary at the center of the nanosheet and in the corner of nanosheet with diameters of 2 and 3 nm for silicon and diamond clusters on boron and nitrogen doped polycrystalline graphene.

  1. Analysis of boron nitride by flame spectrometry methods

    International Nuclear Information System (INIS)

    Telegin, G.F.; Chapysheva, G.Ya.; Shilkina, N.N.

    1989-01-01

    A rapid method has been developed for determination of free and total boron contents as well as trace impurities in boron nitride by using autoclave sample decomposition followed by atomic emission and atomic absorption determination. The relative standard deviation is not greater than 0.03 in the determination of free boron 0.012 in the determination of total boron content

  2. Chemical vapor deposited boron carbide

    International Nuclear Information System (INIS)

    Mackinnon, I.D.R.; Smith, K.L.

    1987-01-01

    Detailed analytical electron microscope (AEM) studies of yellow whiskers produced by chemical vapor deposition (CVD) show that two basic types of whiskers are produced at low temperatures (between 1200 0 C and 1400 0 C) and low boron to carbon gas ratios. Both whisker types show planar microstructures such as twin planes and stacking faults oriented parallel to, or at a rhombohedral angle to, the growth direction. For both whisker types, the presence of droplet-like terminations containing both Si and Ni indicate that the growth process during CVD is via a vapor-liquid-solid (VLS) mechanisms

  3. Boron enrichment in martian clay.

    Directory of Open Access Journals (Sweden)

    James D Stephenson

    Full Text Available We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration.

  4. Boron Enrichment in Martian Clay

    Science.gov (United States)

    Nagashima, Kazuhide; Freeland, Stephen J.

    2013-01-01

    We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration. PMID:23762242

  5. Positron annihilation in boron nitride

    Directory of Open Access Journals (Sweden)

    N.Amrane

    2006-01-01

    Full Text Available Electron and positron charge densities are calculated as a function of position in the unit cell for boron nitride. Wave functions are derived from pseudopotential band structure calculations and the independent particle approximation (IPM, respectively, for electrons and positrons. It is observed that the positron density is maximum in the open interstices and is excluded not only from ion cores but also to a considerable degree from valence bonds. Electron-positron momentum densities are calculated for (001,110 planes. The results are used in order to analyse the positron effects in BN.

  6. Boron nutrition and yield of alfalfa cultivar crioula in relation to boron supply

    Directory of Open Access Journals (Sweden)

    Santos Anacleto Ranulfo dos

    2004-01-01

    Full Text Available Alfalfa cultivar Crioula (Medicago sativa cv. Crioula is grown in South Brazil and only a few studies on the plants' boron requirement are available. A greenhouse experiment was carried out with alfalfa to measure boron acquisition, production and distribution in the plant; data on critical level and production potentials were recorded. Plants were grown in ground quartz added with 1 L of solution, with the following boron rates: 0, 0.0625, 0.125, 0.25, 0.50, 1.00, and 2.00 mg L-1. Plants were harvested at 46 days of growth. Forage dry mass was increased by boron supply and dry matter accumulation was considerably low in control. Boron concentration in the leaves was higher than in the stems or roots. Boron utilization from the external solution reached 90% at 0.0625 mg L-1 and sharply decreased with further increasing boron rates. Boron concentration and content in the leaves and in plant tops were at maximum when applied boron was between 1.5 and 1.6 mg L-1. Critical levels of boron in plant were 61 mg kg-1 in the leaves and 39 mg kg-1 in plant tops for this cultivar of alfalfa.

  7. Experimental boron neutron capture therapy for melanoma: Systemic delivery of boron to melanotic and amelanotic melanoma

    International Nuclear Information System (INIS)

    Coderre, J.A.; Glass, J.D.; Micca, P.; Greenberg, D.; Packer, S.

    1990-01-01

    The boron-containing melanin precursor analogue p-boronophenylalanine (BPA) has previously been shown to selectively deliver boron to pigmented murine melanomas when administered in a single intragastric dose. If boron neutron capture therapy is to become a clinically useful method of radiation therapy for human malignant melanoma, the boron carrier must be capable of delivering useful amounts of boron to remote tumor sites (metastases) and to poorly pigmented melanomas. The authors have now determined the ability of BPA to accumulate in several nonpigmented melanoma models including human melanoma xenografts in nude mice. The absolute amount of boron in the nonpigmented melanomas was about 50% of the observed in the pigmented counterparts but was still selectively concentrated in the tumor relative to normal tissues in amounts sufficient for effective neutron capture therapy. Single intragastric doses of BPA resulted in selective localization of boron in the amelanotic Greene melanoma carried in the anterior chamber of the rabbit eye and in a pigmented murine melanoma growing in the lungs. The ratio of the boron concentration in these tumors to the boron concentration in the immediately adjacent normal tissue was in the range of 3:1 to 4:1. These distribution studies support the proposal that boron neutron capture therapy may be useful as a regional therapy for malignant melanoma

  8. Separation of boron isotopes by aminated polystyrene-divinylbenzene resins

    International Nuclear Information System (INIS)

    Choi, Sei Young; Baek, Joong Hyun; Kim, Hee Lake

    1991-01-01

    Separation of boron isotopes was carried out by using nonporous aminated polystyrene-divinylbenzene as ion exchangers. After 0.1 M boric acid containing 10% sucrose solution was passed through the column, the boric acid band formed on the column was eluted with pure water of 50% methyl alchol water solution. The contents of boric acid of the fraction were determined with neutralization titrations. The relative mass of boron isotopes of the fractions was analyzed on a mass spectrometer. From these results, we found that separation factors for porous aminated polystyrene-divinylbenzene ion exchanger is larger than value of non porous ion exchanger, and then separation factors for 50%-methanol as eluting agent is larger than the value of pure water. (Author)

  9. Spectrophotometric determination of boron by solvent extraction with hydrobenzoin and crystal violet

    International Nuclear Information System (INIS)

    Sato, Shigeya; Uchikawa, Sumio

    1982-01-01

    A highly sensitive and simple method for the spectrophotometric determination of boron was developed. Boron was found to react with hydrobenzoin in weak alkaline medium to form a complex anion extractable into benzene with crystal violet, and the measurement of the absorbance of crystal violet in the extract at 600 nm enabled the determination of boron indirectly. The recommended procedure is as follows: Take an aliquot of the boron solution (2.0 x 10 - 4 mol l - 1 ) into a 10-ml test tube. Add 1 ml of carbonate buffer solution (pH 9.4) and 0.25 ml of crystal violet solution (1.0 x 10 - 2 mol l - 1 ), and dilute the mixed solution to 4 ml with deionized water. Shake the solution with 4 ml of benzene solution containing hydrobenzoin (2.0 x 10 - 2 mol l - 1 ) for 2 min. Measure the absorbance of the organic phase at 600 nm using a 10-mm glass cell against benzene. The calibration curve obeyed Beer's law on the concentration range from 2.5 x 10 - 6 mol l - 1 to 2.5 x 10 - 5 mol l - 1 of boron, and the apparent molar absorptivity was 3.0 x 10 4 l mol - 1 cm - 1 at 20 0 C. It was found that many kinds of co-existing ions interfered with the determination. However, this method was applicable to the determination of boron in sea water when chloride ion and cations such as Ca(II) and Mg(II) were previously eliminated by treating the sample solution with Ag 2 O and cation exchanger resin. The proposed method is a very simple and rapid one, because this method does not require apparatus other than common laboratories and the evaporation to dryness of sample or removal of the excess of reagent. (author)

  10. Medical aspects of boron-slow neutron capture therapy

    International Nuclear Information System (INIS)

    Sweet, W.H.

    1986-01-01

    Earlier radiations of patients with cerebral tumors disclosed the need: (1) to find a carrier of the boron compound which would leave the blood and concentrate in the tumor, (2) to use a more penetrating neutron beam, and (3) to develop a much faster method for assaying boron in blood and tissue. To some extent number1 has been accomplished in the form of Na 2 B 12 H 11 SH, number2 has yet to be achieved, and number3 has been solved by the measurement of the 478-keV gamma ray when the 10 B atom disintegrates following its capture of a slow neutron. The hitherto unreported data in this paper describe through the courtesy of Professor Hiroshi Hatanaka his studies on the pharmacokinetics and quality control of Na 2 B 12 H 11 SH based on 96 boron infusions in 86 patients. Simultaneous blood and tumor data are plotted here for 30 patients with glioblastomas (Grade III-IV gliomas), illustrating remarkable variability. Detailed autopsy findings on 18 patients with BNCT showed radiation injury in only 1. Clinical results in 12 of the most favorably situated glioblastomas reveal that 5 are still alive with a 5-year survival rate of 58% and the excellent Karnofsky performance rating of 87%. For the first time evidence is presented that slow-growing astrocytomas may benefit from BNCT. 10 references, 8 figures, 5 tables

  11. Ferrate(VI synthesis at boron-doped diamond anode

    Directory of Open Access Journals (Sweden)

    Čekerevac Milan

    2013-01-01

    Full Text Available The oxidation of iron compounds from alkaline 10 M KOH electrolytes on a boron doped diamond electrode is examined by cyclic voltammetry between the potentials of hydrogen evolution reaction and oxygen evolution reaction, due to ferrate(VI electrochemical synthesis. It is shown that the anodic current peak that appears in iron free electrolyte at a less positive potential than the potential of oxygen evolution probably coincides with oxidation of hydrogen in >CH2 groups and C-sp2 graphite impurities with formation of >C=O groups at C-sp3 diamond structure. Addition of Fe(III compounds to the electrolyte provoke formation of the anodic wave on cyclic voltammograms in the potential region which correlates with generation of ferrate(VI. It is concluded that the direct electrochemical synthesis of Fe(VI at the boron doped diamond anode is possible because of the less positive potential of ferrate(VIFeO2-4 formation in respect to the potential of oxygen evolution reaction. Presence of ferrate(VI in electrolyte, formed after anodic polarization of boron electrode in 10 M KOH electrolyte saturated with Fe(III at + 0.9 V against Hg|HgO electrode, has been proven by UV-VIS spectrometry.

  12. Analysis of Boron Distribution in Steel using Neutron at HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Eun-Joo; Seong, Baek-Seok; Kim, Hark-Rho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2007-07-01

    Boron is very useful element in steels to improve the mechanical properties. In steel matrix, boron exist several types such as solute, segregation in grain boundary and many kinds of precipitate, which influence the properties of the steel. But, detecting of boron using X-ray or ion-beam is not easy because boron is very light atom than iron. However neutron gives the clear image of boron distribution from the particle tracking autoradiography (PTA) method. The PTA method of boron uses the phenomenon that boron irradiated by neutron emits Liion and alpha particle. Boron distribution can be obtained by observing the traces of the emitted Li-ion and alpha particle. At HANARO, the study for observing of boron distribution has been performed several years ago. Recently, the experimental techniques were improved for the reactor power of 30 MW. In this paper, improved experimental techniques were described and some results for boron added low-carbon steel plate were introduced.

  13. Boron in siliceous materials as a paleosalinity indicator *

    Science.gov (United States)

    Furst, Marian J.

    1981-01-01

    The 10B(n, α) 7Li nuclear reaction has been used with alpha-sensitive plastic track detectors to determine boron concentrations in siliceous live-collected and fossil sponge spicules. This radiographic technique allows B determinations with 5-6% uncertainties on objects 20-25 μm in diameter and for concentrations as low as 0.5 ppm. Boron concentrations in spicules from different specimens from the same location agreed to within 10% when the spicules were not: (1) smaller than 20 μm in diameter, (2) from dictyonine skeletons, (3) the extremely large root-like spicules found in some soft substrate hexactinellids, or (4) microscleres. These criteria also applied to spicules found in sediment samples. Spicules from live-collected sponges exhibited a taxonomy-independent correlation of B concentrations with water salinity for samples from regions of low water temperature and high productivity. Measured concentrations ranged from nearly 0 ppm B (freshwater sponges) to 500-700 ppm (marine sponges), with intermediate values for brackish-water specimens. However, spicules from tropical, low-productivity marine locations contained markedly less boron than spicules from temperate, high-productivity regions. Thus, water temperature and/or food supply also seem to influence B concentrations. Pleistocene spicules from deep-sea cores contained less boron than was expected in comparison with live-collected spicules based on present water temperatures and nutrient supplies, but B concentrations did not vary with depth in the cores. Infrared spectroscopy, electron microprobe analysis and visual inspection revealed no evidence for chemical or mineralogic alteration. It is not clear whether the lower B concentrations of the Pleistocene samples are the result of diagenetic processes or the as yet undefined effects of differences in food supply and/or environmental conditions.

  14. Study of boron detection limit using the in-air PIGE set-up at LAMFI-USP

    International Nuclear Information System (INIS)

    Moro, M. V.; Silva, T. F.; Trindade, G. F.; Added, N.; Tabacniks, M. H.

    2014-01-01

    The quantification of small amounts of boron in materials is of extreme importance in different areas of materials science. Boron is an important contaminant and also a silicon dopant in the semiconductor industry. Boron is also extensively used in nuclear power plants, either for neutron shielding or for safety control and boron is an essential nutrient for life, either vegetable or animal. The production of silicon solar cells, by refining metallurgical-grade silicon (MG-Si) requires the control and reduction of several silicon contaminants to very low concentration levels. Boron is one of the contaminants of solar-grade silicon (SG-Si) that must be controlled and quantified at sub-ppm levels. In the metallurgical purification, boron quantification is usually made by Inductive Coupled Plasma Mass Spectrometry, (ICP-MS) but the results need to be verified by an independent analytical method. In this work we present the results of the analysis of silicon samples by Particle Induced Gamma-Ray Emission (PIGE) aiming the quantification of low concentrations of boron. PIGE analysis was carried out using the in-air external beam line of the Laboratory for Materials Analysis with Ion Beams (LAMFI-USP) by the 10 B(p,αγ( 7 Be nuclear reaction, and measuring the 429 keV γ-ray. The in-air PIGE measurements at LAMFI have a quantification limit of the order of 10 16 at/cm 2

  15. Termite Resistance of MDF Panels Treated with Various Boron Compounds

    OpenAIRE

    Usta, Mustafa; Ustaomer, Derya; Kartal, Saip Nami; Ondaral, Sedat

    2009-01-01

    In this study, the effects of various boron compounds on the termite resistance of MDF panels were evaluated. Either borax (BX), boric acid (BA), zinc borate (ZB), or sodium perborate tetrahydrate (SPT) were added to urea-formaldehyde (UF) resin at target contents of 1%, 1.5%, 2% and 2.5% based on dry fiber weight. The panels were then manufactured using 12% urea-formaldehyde resin and 1% NH4Cl. MDF samples from the panels were tested against the subterranean termites, Coptotermes formosanus ...

  16. Boron-Loaded Silicone Rubber Scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Bell, Z.W.; Maya, L.; Brown, G.M.; Sloop, F.V.Jr

    2003-05-12

    Silicone rubber received attention as an alternative to polyvinyltoluene in applications in which the scintillator is exposed to high doses because of the increased resistance of the rubber to the formation of blue-absorbing color centers. Work by Bowen, et al., and Harmon, et al., demonstrated their properties under gamma/x-ray irradiation, and Bell, et al. have shown their response to thermal neutrons. This last work, however, provided an example of a silicone in which both the boron and the scintillator were contained in the rubber as solutes, a formulation which led to the precipitation of solids and sublimation of the boron component. In the present work we describe a scintillator in which the boron is chemically bonded to the siloxane and so avoids the problem of precipitation and loss of boron to sublimation. Material containing up to 18% boron, by weight, was prepared, mounted on photomultipliers, and exposed to both neutron and gamma fluxes. Pulse height spectra showing the neutron and photon response were obtained, and although the light output was found to be much poorer than from samples in which boron was dissolved, the higher boron concentrations enabled essentially 100% neutron absorption in only a few millimeters' thickness of rubber.

  17. New Experimental Setup for Boron Isotopes Separation by the Laser Assisted Retardation of Condensation Method.

    Science.gov (United States)

    Lyakhov, Konstantin; Lee, Heon-Ju

    2015-11-01

    Demand in isotopically pure boron is steadily growing in industry and medicine. It makes necessary to search for cheaper ways of isotopes production. We propose a new experimental setup design for boron isotope separation by laser assisted retardation of condensation (SILARC) method based on an energy efficiency use relevant optimization method. This optimization method is based on the transport model for rarefied gas flow dynamics in laser field with frequency tuned for excitation of specific isotopomer. Because product cut and enrichment factor corresponding to the optimal conditions are rather small, target isotopomers should be recovered iteratively.

  18. 10 CFR 50.62 - Requirements for reduction of risk from anticipated transients without scram (ATWS) events for...

    Science.gov (United States)

    2010-01-01

    ... into the reactor pressure vessel a borated water solution at such a flow rate, level of boron concentration and boron-10 isotope enrichment, and accounting for reactor pressure vessel volume, that the... minute of 13 weight percent sodium pentaborate decahydrate solution at the natural boron-10 isotope...

  19. Electrical and thermal conductivities of the graphene, boron nitride and silicon boron honeycomb monolayers

    Energy Technology Data Exchange (ETDEWEB)

    Mousavi, Hamze, E-mail: hamze.mousavi@gmail.com [Department of Physics, Razi University, Kermanshah (Iran, Islamic Republic of); Khodadadi, Jabbar [Department of Physics, Razi University, Kermanshah (Iran, Islamic Republic of); Moradi Kurdestany, Jamshid [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65201 (United States); Yarmohammadi, Zahra [Department of Physics, Razi University, Kermanshah (Iran, Islamic Republic of)

    2016-11-25

    Density of states, electrical and thermal conductivities of electrons in graphene, boron nitride and silicon boron single sheets are studied within the tight-binding Hamiltonian model and Green's function formalism, based on the linear response theory. The results show that while boron nitride keeps significantly the lowest amounts overall with an interval of zero value in low temperatures, due to its insulating nature, graphene exhibits the most electrical and thermal conductivities, slightly higher than silicon boron except for low temperature region where the latter surpasses, owing to its metallic character. This work might make ideas for creating new electronic devices based on honeycomb nanostructures. - Highlights: • Electronic properties of graphene, silicon boron, and boron nitride planes are compared. • Tight-binding Hamiltonian model and Green's function formalism are implemented. • This work might make ideas for creating new electronic devices based on honeycomb nanostructures.

  20. The determination of boron and carbon in reactor grade boron carbide

    International Nuclear Information System (INIS)

    Crossley, D.; Wood, A.J.; McInnes, C.A.J.; Jones, I.G.

    1978-09-01

    The sealed tube method of dissolution at high temperature and pressure has been successfully applied in the analysis of reactor grade boron carbide for the determination of boron. A 50 mg sample of boron carbide is completely dissolved by heating with concentrated nitric acid in a sealed tube at 300 0 C. The boron content of the resultant sample solution is determined by the mannitol potentiometric titration method. The precision of the method for the determination of 2.5 mg of boron using the Harwell automatic potentiometric titrator is 0.2% (coefficient of variation). The carbon content of a boron carbide sample is determined by combustion of the sample at 1050 0 C in a stream of oxygen using vanadium pentoxide to ensure the complete oxidation of the sample. The carbon dioxide produced from the sample is measured manometrically and the precision of the method for the determination of 4 mg of carbon is 0.4% (coefficient of variation). (author)

  1. In situ synthesis of a large area boron nitride/graphene monolayer/boron nitride film by chemical vapor deposition

    Science.gov (United States)

    Wu, Qinke; Jang, Sung Kyu; Park, Sangwoo; Jung, Seong Jun; Suh, Hwansoo; Lee, Young Hee; Lee, Sungjoo; Song, Young Jae

    2015-04-01

    We describe the successful in situ chemical vapor deposition synthesis of a graphene-based heterostructure in which a graphene monolayer is protected by top and bottom boron nitride films. The boron nitride film/graphene monolayer/boron nitride film (BGB) was found to be a mechanically robust and chemically inert heterostructure, from which the deleterious effects of mechanical transfer processes and unwanted chemical doping under air exposure were eliminated. The chemical compositions of each film layer were monitored ex situ using UV-visible absorption spectroscopy and X-ray photoelectron spectroscopy, and the crystalline structures were confirmed using transmission electron microscopy and selected-area electron diffraction measurements. The performance of the devices fabricated using the BGB film was monitored over six months and did not display large changes in the mobility or the Dirac point, unlike the conventional graphene devices prepared on a SiO2 substrate. The in situ-grown BGB film properties suggest a novel approach to the fabrication of commercial-grade graphene-based electronic devices.We describe the successful in situ chemical vapor deposition synthesis of a graphene-based heterostructure in which a graphene monolayer is protected by top and bottom boron nitride films. The boron nitride film/graphene monolayer/boron nitride film (BGB) was found to be a mechanically robust and chemically inert heterostructure, from which the deleterious effects of mechanical transfer processes and unwanted chemical doping under air exposure were eliminated. The chemical compositions of each film layer were monitored ex situ using UV-visible absorption spectroscopy and X-ray photoelectron spectroscopy, and the crystalline structures were confirmed using transmission electron microscopy and selected-area electron diffraction measurements. The performance of the devices fabricated using the BGB film was monitored over six months and did not display large changes in the

  2. Full-scale simulation of seawater reverse osmosis desalination processes for boron removal: Effect of membrane fouling.

    Science.gov (United States)

    Park, Pyung-Kyu; Lee, Sangho; Cho, Jae-Seok; Kim, Jae-Hong

    2012-08-01

    The objective of this study is to further develop previously reported mechanistic predictive model that simulates boron removal in full-scale seawater reverse osmosis (RO) desalination processes to take into account the effect of membrane fouling. Decrease of boron removal and reduction in water production rate by membrane fouling due to enhanced concentration polarization were simulated as a decrease in solute mass transfer coefficient in boundary layer on membrane surface. Various design and operating options under fouling condition were examined including single- versus double-pass configurations, different number of RO elements per vessel, use of RO membranes with enhanced boron rejection, and pH adjustment. These options were quantitatively compared by normalizing the performance of the system in terms of E(min), the minimum energy costs per product water. Simulation results suggested that most viable options to enhance boron rejection among those tested in this study include: i) minimizing fouling, ii) exchanging the existing SWRO elements to boron-specific ones, and iii) increasing pH in the second pass. The model developed in this study is expected to help design and optimization of the RO processes to achieve the target boron removal at target water recovery under realistic conditions where membrane fouling occurs during operation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Effect of boron concentration on physicochemical properties of boron-doped carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Keru, Godfrey; Ndungu, Patrick G.; Nyamori, Vincent O., E-mail: nyamori@ukzn.ac.za

    2015-03-01

    Boron-doped carbon nanotubes (B-CNTs) were synthesized using chemical vapour deposition (CVD) floating catalyst method. Toluene was used as the carbon source, triphenylborane as boron as well as the carbon source while ferrocene was used as the catalyst. The amount of triphenylborane used was varied in a solution of toluene and ferrocene. Ferrocene was kept constant at 2.5 wt.%. while a maximum temperature of 900 °C was used for the synthesis of the shaped carbon nanomaterial (SCNMs). SCNMs obtained were characterized by the use of transmission electron microscope (TEM), scanning electron microscope (SEM), high resolution-electron microscope, electron dispersive X-ay spectroscopy (EDX), Raman spectroscopy, inductively coupled plasma-optical emission spectroscopy (ICP-OES), vibrating sample magnetometer (VSM), nitrogen adsorption at 77 K, and inverse gas chromatography. TEM and SEM analysis confirmed SCNMs obtained were a mixture of B-CNTs and carbon nanofibres (B-CNF). EDX and ICP-OES results showed that boron was successively incorporated into the carbon hexagonal network of CNTs and its concentration was dependent on the amount of triphenylborane used. From the VSM results, the boron doping within the CNTs introduced ferromagnetic properties, and as the percentage of boron increased the magnetic coactivity and squareness changed. In addition, boron doping changed the conductivity and the surface energy among other physicochemical properties of B-CNTs. - Highlights: • Boron-doping of carbon nanotubes (CNTs) changes their physiochemical properties. • Amount of boron-doping was dependent on the wt.% of boron precursor used. • Boron-doping changed CNTs surfaces and the distribution of dispersive energy sites. • Boron-doping affected the conductivity and ferromagnetic properties. • Increased boron-doping results in a more favourable interaction with polar probes.

  4. An analysis of national target groups for monovalent 2009 pandemic influenza vaccine and trivalent seasonal influenza vaccines in 2009-10 and 2010-11

    Directory of Open Access Journals (Sweden)

    Lee Esther ST

    2011-08-01

    Full Text Available Abstract Background Vaccination is generally considered to be the best primary prevention measure against influenza virus infection. Many countries encourage specific target groups of people to undertake vaccination, often with financial subsidies or a priority list. To understand differential patterns of national target groups for influenza vaccination before, during and after the 2009 influenza pandemic, we reviewed and analyzed the country-specific policies in the corresponding time periods. Methods Information on prioritized groups targeted to receive seasonal and pandemic influenza vaccines was derived from a multi-step internet search of official health department websites, press releases, media sources and academic journal articles. We assessed the frequency and consistency of targeting 20 different groups within populations which are associated with age, underlying medical conditions, role or occupations among different countries and vaccines. Information on subsidies provided to specific target groups was also extracted. Results We analyzed target groups for 33 (seasonal 2009 and 2009-10 vaccines, 72 (monovalent pandemic 2009-10 vaccine and 34 (seasonal 2010 and 2010-11 vaccines countries. In 2009-10, the elderly, those with chronic illness and health care workers were common targets for the seasonal vaccine. Comparatively, the elderly, care home residents and workers, animal contacts and close contacts were less frequently targeted to receive the pandemic vaccine. Pregnant women, obese persons, essential community workers and health care workers, however, were more commonly targeted. After the pandemic, pregnant women, obese persons, health care and care home workers, and close contacts were more commonly targeted to receive the seasonal vaccine compared to 2009-10, showing continued influence from the pandemic. Many of the countries provided free vaccines, partial subsidies, reimbursements or national health insurance coverage to

  5. Boron Isotope Fractionation in Bell Pepper

    OpenAIRE

    Geilert, Sonja; Vogl, Jochen; Rosner, Martin; Voerkelius, Susanne; Eichert, Thomas

    2015-01-01

    Various plant compartments of a single bell pepper plant were studied to verify the variability of boron isotope composition in plants and to identify possible intra-plant isotope fractionation. Boron mass fractions varied from 9.8 mg/kg in the fruits to 70.0 mg/kg in the leaves. Boron (B) isotope ratios reported as δ11B ranged from -11.0‰ to +16.0‰ (U ≤ 1.9‰, k=2) and showed a distinct trend to heavier δ11B values the higher the plant compartments were located in the plant. A fractionatio...

  6. Study on plasma sprayed boron carbide coating

    Science.gov (United States)

    Zeng, Yi; Lee, Soo W.; Ding, Chuanxian

    2002-03-01

    The microstructure, phase composition, and mechanical properties of boron carbide coatings formed by atmospheric plasma spraying (APS) are studied in the present work. The boron carbide coating with high microhardness and low porosity could be produced by APS. The decomposition of boron carbide powder during the plasma spray process would result in the formation of the BxC phase and an increase of the carbon phase, which is confirmed by transmission electron microscopy, x-ray photoelectron spectroscopy, and x-ray diffraction results.

  7. Kinetic investigation of AISI 304 Stainless Steel boronized in indirect heated fluidized bed furnace

    Directory of Open Access Journals (Sweden)

    Topuz P.

    2016-01-01

    Full Text Available In this study, kinetic examinations on boronized AISI 304 Stainless Steel samples were described. Samples were boronized in indirect heated fluidized bed furnace consists of Ekabor 1™ boronizing agent at 1123, 1223 and 1323 K for 1,2 and 4 hours. Morphologically and typically examinations of borides formed on the surface of steel samples were studied by optical microscope, scanning electron microscope (SEM and X-Ray diffraction (XRD. Boride layer thickness formed on the steel X5CrNi 18-10 ranges from 12 to 176 μm. The hardness of the boride layer formed on the steel X5CrNi 18-10 varied between 1709 and 2119 Hv0,1. Layer growth kinetics were analyzed by measuring the extent of penetration of FeB and Fe2B sublayers as a function of boronizing time and temperature. The kinetics of the reaction has been determined with K=Ko exp (-Q/RT equation. Activation energy (Q of boronized steel X5CrNi 18-10 was determined as 244 kj/mol.

  8. "Sequential” Boron Neutron Capture Therapy (BNCT): A Novel Approach to BNCT for the Treatment of Oral Cancer in the Hamster Cheek Pouch Model

    Energy Technology Data Exchange (ETDEWEB)

    Ana J. Molinari; Andrea Monti Hughes; Elisa M. Heber; Marcela A. Garabalino; Veronica A. Trivillin; Amanda E. Schwint; Emiliano C. C. Pozzi; Maria E. Itoiz; Silvia I. Thorp; Romina F. Aromando; David W. Nigg; Jorge Quintana; Gustavo A. Santa Cruz

    2011-04-01

    Boron Neutron Capture Therapy (BNCT) is a binary treatment modality that involves the selective accumulation of 10B carriers in tumors followed by irradiation with a thermal or epithermal neutron beam. The minor abundance stable isotope of boron, 10B, interacts with low energy (thermal) neutrons to produce high linear energy transfer (LET) a-particles and 7Li ions. These disintegration products are known to have a high relative biological effectiveness (RBE). Their short range (<10 {micro}m) would limit the damage to cells containing 10B (1,2). Thus, BNCT would target tumor tissue selectively, sparing normal tissue. Clinical trials of BNCT for the treatment of glioblastoma multiforme and/or melanoma and, more recently, head and neck tumors and liver metastases, using boronophenylalanine (BPA) or sodium mercaptoundecahydrododecaborane (BSH) as the 10B carriers, have been performed or are underway in Argentina, Japan, the US and Europe (e.g. 3-8). To date, the clinical results have shown a potential, albeit inconclusive, therapeutic advantage for this technique. Contributory translational studies have been carried out employing a variety of experimental models based on the implantation of tumor cells in normal tissue (e.g. 5).

  9. Boronic Acid Group: A Cumbersome False Negative Case in the Process of Drug Design

    Directory of Open Access Journals (Sweden)

    Sotirios Katsamakas

    2016-09-01

    Full Text Available Herein we present, an exhaustive docking analysis considering the case of autotaxin (ATX. HA155, a small molecule inhibitor of ATX, is co-crystallized. In order to further extract conclusions on the nature of the bond formed between the ligands and the amino acid residues of the active site, density functional theory (DFT calculations were undertaken. However, docking does not provide reproducible results when screening boronic acid derivatives and their binding orientations to protein drug targets. Based on natural bond orbital (NBO calculations, the formed bond between Ser/Thr residues is characterized more accurately as a polar covalent bond instead of a simple nonpolar covalent one. The presented results are acceptable and could be used in screening as an active negative filter for boron compounds. The hydroxyl groups of amino acids are bonded with the inhibitor’s boron atom, converting its hybridization to sp3.

  10. Study of extraction-spectrophotometric micro-determination of boron with methylene blue and its application

    International Nuclear Information System (INIS)

    Zhu Daohong

    1990-08-01

    A sensitive extraction-spectrophotometric method for microdetermination of boron with methylene blue was investigated. The method was based on the extraction of a BF 4 - -methylene blue complex into dichloroethane. Boron was determined directly by measuring the absorbance at 658 nm. The calibration graph was linear over the range of 2.5 x 10 -9 to 8 x 10 -8 g/mL. The blank, mechanism of the reactions, interference of other ions and some optimum conditions of the method were studied in detail. The main source of the blank resulted from methylene blue and the complex of F - -methylene blue. In order to reduce the blank, the amounts of methylene blue, H 2 SO 4 and HF were used as less as possible. Only one to one complex BF 4 - -methylene blue was formed in the medium of H 2 SO 4 . About 90% of methylene blue and F - -methylene blue complex was removre with 5 ml of water and only a little amount of BF 4 -methylene blue complex was decomposed. The extraction-spectrophotometric method with methylene blue was first applied to the microdetermination of boron in sodium metal and UF 6 . The sample of sodium metal was taken and weighed in the glovebox filled with argon. Then sodium metal was oxidized, hydrolyzed, netralized and fluorizated with H 2 O, H 2 SO 4 and HF, respectively. The 0.5 ppm of boron in sodium metal was determined with a relative error about ±4%. This method can be applied to the determination of boron in sodium metal, sodium sulfate and sodium hydroxide at diffeent grades. The species of boron in the hydrolysate of UF 6 is BF 4 - anion, so the sample can be directly analyzed. Boron contents in the range of 0.1 to 0.5 ppm was determined with a relative error about ±3%. Six samples could be analysed in 2h

  11. Application of HVJ envelope system to boron neutron capture therapy (BNCT)

    International Nuclear Information System (INIS)

    Nakai, Kei; Kurooka, Masaaki; Kaneda, Yasufumi; Yamamoto, Tetsuya; Matsumura, Akira; Asano, Tomoyuki

    2006-01-01

    Boron Neutron Capture Therapy (BNCT) has been used clinically for the treatment of malignant tumors. Two drugs, p-boronophenylalanine (BPA) and sulfhydral borane (BSH), have been used as boron delivery agents. These drugs seem to be taken up preferentially in solid tumors, but it is uncertain whether therapeutic quantities of boron atoms are taken up by micro-invasive or distant tumor cells. High accumulation and high selective delivery of boron into tumor tissues are the most important requirements to achieve efficient BNCT for malignant tumor. The HVJ envelope (HVJ-E) vector system is a novel fusion-mediated gene delivery system based on inactivated hemagglutinating virus of Japan (HVJ; Sendai virus). Although we developed this vector system for gene transfer, it can also deliver proteins, synthetic oligonucleotides, and drugs. HVJ-liposome, which is liposome fused with HVJ-E, has higher boron trapping efficiency than HVJ-E alone. We report the boron delivery into cultured cells with HVJ-liposome systems. The cellular 10 B concentration after 60 min incubation with HVJ-E containing BSH was 24.9 μg/g cell pellet for BHK-21 cells (baby hamster kidney cells) and 19.4 μg/g cell pellet for SCC VII cells (murine squamous cell carcinoma). These concentrations are higher than that of 60 min incubated cells with BSH containing (100μg 10 B/ml) medium. These results indicate the HVJ-E fused with tumor cell membrane and rapidly delivered boron agents, and that the HVJ-E-mediated delivery system could be applicable to BNCT. Plans are underway to begin neutron radiation experiments in vivo and in vitro. (author)

  12. Characterization of boron tolerant bacteria isolated from a fly ash dumping site for bacterial boron remediation.

    Science.gov (United States)

    Edward Raja, Chellaiah; Omine, Kiyoshi

    2013-08-01

    Boron is an essential micronutrient for plants, but can above certain concentrations be toxic to living organisms. A major environmental concern is the removal of boron from contaminated water and fly ash. For this purpose, the samples were collected from a fly ash dumping site, Nagasaki prefecture, Japan. The chemical characteristics and heavy metal concentration of the samples were performed by X-ray fluorescent analysis and leaching test. For bacterial analysis, samples were collected in sterile plastic sheets and isolation was carried out by serial dilution method. The boron tolerant isolates that showed values of maximum inhibitory concentration toward boron ranging from 100 to 260 mM level were screened. Based on 16S rRNA sequencing and phylogenetic analysis, the isolates were most closely related to the genera Bacillus, Lysinibacillus, Microbacterium and Ralstonia. The boron tolerance of these strains was also associated with resistant to several heavy metals, such as As (III), Cr (VI), Cd, Cu, Pb, Ni, Se (III) and Zn. Indeed, these strains were arsenic oxidizing bacteria confirmed by silver nitrate test. These strains exhibited their salt resistances ranging from 4 to 15 % were determined in Trypticase soy agar medium. The boron tolerant strains were capable of removing 0.1-2.0 and 2.7-3.7 mg l(-1) boron from the medium and fly ash at 168 h. Thus, we have successfully identified the boron tolerant and removal bacteria from a fly ash dumping site for boron remediation.

  13. WEED CONTROL AND BORON NUTRITION ON Eucalyptus IN SILVOPASTORAL SYSTEM

    Directory of Open Access Journals (Sweden)

    Alexandre Magno Brighenti

    2015-04-01

    Full Text Available The objective of this study was to evaluate the control of weeds in the rows of eucalyptus (Eucalyptus urograndis with herbicides applied singly or combined with boron (B, as well as, the response of Eucalyptus plants to this micronutrient. The experiments were carried out in a split-plot with randomized complete block design, with three replicates. Six treatments were applied to the plots: (i weeded control, (ii control without weeding, (iii glyphosate (1080 g ae ha-1 + chlorimuron-ethyl (10 g ai ha-1 + 0.05% v / v mineral oil, (iv glyphosate (1080 g ae  ha-1 + isoxaflutole (112.5 g ai ha-1,  (v glyphosate (1080 g ae ha-1 and  (vi oxyfluorfen (480 g ai ha-1. The sub-plots consisted of the absence or presence of 4 kg of boric acid (H3BO3 - 17% B in 100 L of water. The addition of boric acid in the solution containing the herbicides did not affect the weed control. There was an increase in boron content in the soil and consequently an increase in the boron levels in the eucalyptus leaves. The combined application of herbicides plus boric acid is perfectly suitable for preventing dry of the pointer on eucalyptus plants. Keywords: Eucalyptus urograndis; chemical control; herbicides; micronutrients; Urochloa decumbens.

  14. Facile synthesis of a boronate affinity sorbent from mesoporous nanomagnetic polyhedral oligomeric silsesquioxanes composite and its application for enrichment of catecholamines in human urine

    Energy Technology Data Exchange (ETDEWEB)

    He, Haibo, E-mail: hbhe2006@shu.edu.cn [Department of Chemistry, Shanghai University, Shanghai 200444 (China); Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072 (China); Zhou, Ziqing; Dong, Chen; Wang, Xin [Department of Chemistry, Shanghai University, Shanghai 200444 (China); Yu, Qiong-wei [Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072 (China); Lei, Yunyi; Luo, Liqiang [Department of Chemistry, Shanghai University, Shanghai 200444 (China); Feng, Yuqi [Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072 (China)

    2016-11-09

    A boronate-decorated nanomagnetic organic-inorganic hybrid material was facilely synthesized by utilizing the nanomagnetic polyhedral oligomeric silsesquioxanes (POSS) composite (Fe{sub 3}O{sub 4}@POSS) as the base platform. A simple copolymerization occurred between 3-acrylamidophenylboronic acid (AAPBA) and the residual end vinyl groups supplied by the substrate. Here the special emphasis was placed on the octavinyl POSS, which not only acted as the building blocks for a hybrid architecture but also facilitated the process of grafting boronate groups onto the surface of POSS based nanomagnetic composite (Fe{sub 3}O{sub 4}@POSS). The successful immobilization of affinity ligand-AAPBA on the Fe{sub 3}O{sub 4}@POSS was confirmed by Fourier transform infrared (FT-IR), elemental analysis, inductively coupled plasma atomic emission spectrometer (ICP-AES), field emission scanning electron microscope. A magnetic solid-phase extraction (MSPE) for cis-diols enrichment was developed using the as-prepared Fe{sub 3}O{sub 4}@POSS-AAPBA material as an affinity sorbent and three catecholamines (CAs), namely noradrenaline, epinephrine and isoprenaline, as model analytes. Under the optimal extraction conditions, sensitive and simultaneous analysis of three CAs from the urine sample was achieved by high-performance liquid chromatography with UV detection (HPLC-UV). The limits of detection (LOD, S/N = 3) and the limits of quantitation (LOQ, S/N = 10) for the target analytes were 0.81–1.32 ng mL{sup −1} and 2.70–4.40 ng mL{sup −1}, respectively. Also good recoveries (85.5–101.7%) and repeatability (RSD≤10.1%) were obtained by this method. This work not only showed a facility for the utilization of Fe{sub 3}O{sub 4}@POSS as a substrate for constructing a boronate functionalized nanomagnetic sorbent, but also demonstrated the capability of the derived material for recognition of trace amount of cis-diols biomolecules presented in complicated biological matrices

  15. Study of the roles of chemical modifiers in determining boron using graphite furnace atomic absorption spectrometry and optimization of the temperature profile during atomization.

    Science.gov (United States)

    Yamamoto, Yuhei; Shirasaki, Toshihiro; Yonetani, Akira; Imai, Shoji

    2015-01-01

    The measurement conditions for determining boron using graphite furnace-atomic absorption spectrometry (GF-AAS) were investigated. Differences in the boron absorbance profiles were found using three different commercially available GF-AAS instruments when the graphite atomizers in them were not tuned. The boron absorbances found with and without adjusting the graphite atomizers suggested that achieving an adequate absorbance for the determination of boron requires a sharp temperature profile that overshoots the target temperature during the atomization process. Chemical modifiers that could improve the boron absorbance without the need for using coating agents were tested. Calcium carbonate improved the boron absorbance but did not suppress variability in the peak height. Improvement of boron absorbance was comparatively less using iron nitrate or copper nitrate than using calcium carbonate, but variability in the peak height was clearly suppressed using iron nitrate or copper nitrate. The limit of detection was 0.0026 mg L(-1) when iron nitrate was used. It appears that iron nitrate is a useful new chemical modifier for the quick and simple determination of boron using GF-AAS.

  16. Boron filled siloxane polymers for radiation shielding

    Science.gov (United States)

    Labouriau, Andrea; Robison, Tom; Shonrock, Clinton; Simmonds, Steve; Cox, Brad; Pacheco, Adam; Cady, Carl

    2018-03-01

    The purpose of the present work was to evaluate changes to structure-property relationships of 10B filled siloxane-based polymers when exposed to nuclear reactor radiation. Highly filled polysiloxanes were synthesized with the intent of fabricating materials that could shield high neutron fluences. The newly formulated materials consisted of cross-linked poly-diphenyl-methylsiloxane filled with natural boron and carbon nanofibers. This polymer was chosen because of its good thermal and chemical stabilities, as well as resistance to ionizing radiation thanks to the presence of aromatic groups in the siloxane backbone. Highly isotopically enriched 10B filler was used to provide an efficient neutron radiation shield, and carbon nanofibers were added to improve mechanical strength. This novel polymeric material was exposed in the Annular Core Research Reactor (ACRR) at Sandia National Labs to five different neutron/gamma fluxes consisting of very high neutron fluences within very short time periods. Thermocouples placed on the specimens recorded in-situ temperature changes during radiation exposure, which agreed well with those obtained from our MCNP simulations. Changes in the microstructural, thermal, chemical, and mechanical properties were evaluated by SEM, DSC, TGA, FT-IR NMR, solvent swelling, and uniaxial compressive load measurements. Our results demonstrate that these newly formulated materials are well-suitable to be used in applications that require exposure to different types of ionizing conditions that take place simultaneously.

  17. Boron Doped Graphene 3-Dimensi untuk Superkapasitor Kapasitas Tinggi

    Directory of Open Access Journals (Sweden)

    Nurlia Pramita Sari

    2017-08-01

    Full Text Available Chemical doping is an effective approach to improve the property of carbon material. In this study boron doped graphene with 3D structure used as the electrode was investigated. Boron doped graphene was prepared through freeze-dried process followed by pyrolysis of graphene oxide (GO with three types of chemical substances; boron oxide, boric acid, and boron powder in an argon and hydrogen atmosphere at 1000 C for 3 hours. The difference of chemical composition generated a different percentage of boron bond with GO. The results shows that the highest electrochemical performance was found in graphene samples with the addition of boric acid (BA 86 F/g, followed by boron oxide (BO 59.2 F/g, and boron powder (BP 2 F/g. It can be caused by boron concentration bound with graphene. The higher concentration of boron could be increased the electrochemical performance due to better of ion movement.

  18. Breaking the icosahedra in boron carbide.

    Science.gov (United States)

    Xie, Kelvin Y; An, Qi; Sato, Takanori; Breen, Andrew J; Ringer, Simon P; Goddard, William A; Cairney, Julie M; Hemker, Kevin J

    2016-10-25

    Findings of laser-assisted atom probe tomography experiments on boron carbide elucidate an approach for characterizing the atomic structure and interatomic bonding of molecules associated with extraordinary structural stability. The discovery of crystallographic planes in these boron carbide datasets substantiates that crystallinity is maintained to the point of field evaporation, and characterization of individual ionization events gives unexpected evidence of the destruction of individual icosahedra. Statistical analyses of the ions created during the field evaporation process have been used to deduce relative atomic bond strengths and show that the icosahedra in boron carbide are not as stable as anticipated. Combined with quantum mechanics simulations, this result provides insight into the structural instability and amorphization of boron carbide. The temporal, spatial, and compositional information provided by atom probe tomography makes it a unique platform for elucidating the relative stability and interactions of primary building blocks in hierarchically crystalline materials.

  19. Boron adsorption on hematite and clinoptilolite

    International Nuclear Information System (INIS)

    Gainer, G.M.

    1993-01-01

    This thesis describes experiments performed to determine the suitability of boron as a potential reactive tracer for use in saturated-zone C-well reactive tracer studies for the Yucca Mountain Project (YMP). Experiments were performed to identify the prevalent sorption mechanism of boron and to determine adsorption of boron on hematite and clinoptilolite as a function of pH. These minerals are present in the Yucca Mountain tuff in which the C-well studies will be conducted. Evaluation of this sorption mechanism was done by determining the equilibration time of boron-mineral suspensions, by measuring changes in equilibrium to titrations, and by measuring electrophoretic mobility. Experiments were performed with the minerals suspended in NaCl electrolytes of concentrations ranging from 0.1 N NaCl to 0.001 N NaCl. Experimentalconditions included pH values between 3 and 12 and temperature of about 38 degrees C

  20. Determination of boron in amorphous alloys

    Energy Technology Data Exchange (ETDEWEB)

    Grazhulene, S.S.; Grossman, O.V.; Kuntscher, K.K.; Malygina, L.I.; Muller, E.N.; Telegin, G.F.

    1985-10-01

    In the determination of boron in amorphous alloys containingFe, Co, B, Si, Ni, and P having unusal magnetic and electrical properties, precise analysis and rapid analysis are necessary. To improve the metrological properties of the existing procedure, to find a rapid determination of boron in amorphous alloys, and to verify the accuracy of the results, in the present work the optimization of the photometric determination after extraction of the BF/sup -//sub 4/ ion pair with methylene blue has been studied, and a boron determination by flame photometry using selective methylation has been developed. The determination of boron by the flame photometric and spectrophotometric methods is shown. When a highly precise determination is needed, the spectrophotometric procedure can be used. This procedure is distinguished by its labor intensity and duration. When the need for reproducibility is less severe, the rapid flame photometric procedure is best.

  1. Behaviour of boron in Mandovi estuary (Goa)

    Digital Repository Service at National Institute of Oceanography (India)

    Shirodkar, P.V.; Anand, S.P.

    and alkalinity gave positive correlations with a linear variation. Though the overall behavioural pattern of boron indicated non-conservative nature, it showed a quasi-conservative character during premonsoon and a non-conservative during rest of the seasons...

  2. Boron

    Science.gov (United States)

    ... feeding women over 19 years of age. For adolescents 14 to 18 years of age and pregnant or breast-feeding women 14 to 18 years of age, the ... be expected, is 17 mg per day for adolescents 14 to 18 years of age and pregnant or breast-feeding women 14 to 18 years of age. For ...

  3. Abrasive slurry composition for machining boron carbide

    Science.gov (United States)

    Duran, Edward L.

    1985-01-01

    An abrasive slurry particularly suited for use in drilling or machining boron carbide consists essentially of a suspension of boron carbide and/or silicon carbide grit in a carrier solution consisting essentially of a dilute solution of alkylaryl polyether alcohol in octyl alcohol. The alkylaryl polyether alcohol functions as a wetting agent which improves the capacity of the octyl alcohol for carrying the grit in suspension, yet without substantially increasing the viscosity of the carrier solution.

  4. Boron-rich oligomers for BNCT

    International Nuclear Information System (INIS)

    Gula, M.; Perleberg, O.; Gabel, D.

    2000-01-01

    The synthesis of two BSH derivatives is described, which can be used for oligomerization in DNA-synthesizers. Synthesis pathways lead to final products in five and six steps, respectively. Because of chirality interesting results were expected. NMR-measurements confirm this expectation. Possible oligomers with high concentrations of boron can be attached to biomolecules. These oligomers can be explored with several imaging methods (EELS, PEM) to determine the lower detection limit of boron with these methods. (author)

  5. Boron neutron capture synovectomy (BNCS) as a potential therapy for rheumatoid arthritis: radiobiological studies at RA-1 Nuclear Reactor in a model of antigen-induced arthritis in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Trivillin, Veronica A.; Schwint, Amanda E. [Comision Nacional de Energia Atomica (CNEA), Department of Radiobiology, San Martin, Provincia Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Ciudad Autonoma de Buenos Aires (Argentina); Bruno, Leandro J.; Gatti, David A. [Universidad Nacional de Rosario, LABOATEM (Laboratorio de Biologia Osteoarticular, Ingenieria Tisular y Terapias Emergentes), Facultad de Ciencias Medicas, Rosario (Argentina); Stur, Mariela [Universidad Nacional de Rosario, Catedra de Diagnostico por Imagenes, Facultad de Ciencias Medicas, Rosario (Argentina); Garabalino, Marcela A.; Hughes, Andrea Monti [Comision Nacional de Energia Atomica (CNEA), Department of Radiobiology, San Martin, Provincia Buenos Aires (Argentina); Castillo, Jorge; Wentzeis, Luis; Scolari, Hugo [Comision Nacional de Energia Atomica (CNEA), Department of Reactors, San Martin, Provincia Buenos Aires (Argentina); Pozzi, Emiliano C.C. [Comision Nacional de Energia Atomica (CNEA), Department of Research and Production Reactors, Ezeiza, Province Buenos Aires (Argentina); Feldman, Sara [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Ciudad Autonoma de Buenos Aires (Argentina); Universidad Nacional de Rosario, LABOATEM (Laboratorio de Biologia Osteoarticular, Ingenieria Tisular y Terapias Emergentes), Facultad de Ciencias Medicas, Rosario (Argentina)

    2016-11-15

    Rheumatoid arthritis is a chronic autoimmune pathology characterized by the proliferation and inflammation of the synovium. Boron neutron capture synovectomy (BNCS), a binary treatment modality that combines the preferential incorporation of boron carriers to target tissue and neutron irradiation, was proposed to treat the pathological synovium in arthritis. In a previous biodistribution study, we showed the incorporation of therapeutically useful boron concentrations to the pathological synovium in a model of antigen-induced arthritis (AIA) in rabbits, employing two boron compounds approved for their use in humans, i.e., decahydrodecaborate (GB-10) and boronophenylalanine (BPA). The aim of the present study was to perform low-dose BNCS studies at the RA-1 Nuclear Reactor in the same model. Neutron irradiation was performed post intra-articular administration of BPA or GB-10 to deliver 2.4 or 3.9 Gy, respectively, to synovium (BNCS-AIA). AIA and healthy animals (no AIA) were used as controls. The animals were followed clinically for 2 months. At that time, biochemical, magnetic resonance imaging (MRI) and histological studies were performed. BNCS-AIA animals did not show any toxic effects, swelling or pain on palpation. In BNCS-AIA, the post-treatment levels of TNF-α decreased in four of six rabbits and IFN-γ levels decreased in five of six rabbits. In all cases, MRI images of the knee joint in BNCS-AIA resembled those of no AIA, with no necrosis or periarticular effusion. Synovial membranes of BNCS-AIA were histologically similar to no AIA. BPA-BNCS and GB-10-BNCS, even at low doses, would be therapeutically useful for the local treatment of rheumatoid arthritis. (orig.)

  6. Boron neutron capture synovectomy (BNCS) as a potential therapy for rheumatoid arthritis: radiobiological studies at RA-1 Nuclear Reactor in a model of antigen-induced arthritis in rabbits

    International Nuclear Information System (INIS)

    Trivillin, Veronica A.; Schwint, Amanda E.; Bruno, Leandro J.; Gatti, David A.; Stur, Mariela; Garabalino, Marcela A.; Hughes, Andrea Monti; Castillo, Jorge; Wentzeis, Luis; Scolari, Hugo; Pozzi, Emiliano C.C.; Feldman, Sara

    2016-01-01

    Rheumatoid arthritis is a chronic autoimmune pathology characterized by the proliferation and inflammation of the synovium. Boron neutron capture synovectomy (BNCS), a binary treatment modality that combines the preferential incorporation of boron carriers to target tissue and neutron irradiation, was proposed to treat the pathological synovium in arthritis. In a previous biodistribution study, we showed the incorporation of therapeutically useful boron concentrations to the pathological synovium in a model of antigen-induced arthritis (AIA) in rabbits, employing two boron compounds approved for their use in humans, i.e., decahydrodecaborate (GB-10) and boronophenylalanine (BPA). The aim of the present study was to perform low-dose BNCS studies at the RA-1 Nuclear Reactor in the same model. Neutron irradiation was performed post intra-articular administration of BPA or GB-10 to deliver 2.4 or 3.9 Gy, respectively, to synovium (BNCS-AIA). AIA and healthy animals (no AIA) were used as controls. The animals were followed clinically for 2 months. At that time, biochemical, magnetic resonance imaging (MRI) and histological studies were performed. BNCS-AIA animals did not show any toxic effects, swelling or pain on palpation. In BNCS-AIA, the post-treatment levels of TNF-α decreased in four of six rabbits and IFN-γ levels decreased in five of six rabbits. In all cases, MRI images of the knee joint in BNCS-AIA resembled those of no AIA, with no necrosis or periarticular effusion. Synovial membranes of BNCS-AIA were histologically similar to no AIA. BPA-BNCS and GB-10-BNCS, even at low doses, would be therapeutically useful for the local treatment of rheumatoid arthritis. (orig.)

  7. Evaluation of a novel multi-immunogen vaccine strategy for targeting 4E10/10E8 neutralizing epitopes on HIV-1 gp41 membrane proximal external region.

    Science.gov (United States)

    Banerjee, Saikat; Shi, Heliang; Banasik, Marisa; Moon, Hojin; Lees, William; Qin, Yali; Harley, Andrew; Shepherd, Adrian; Cho, Michael W

    2017-05-01

    The membrane proximal external region (MPER) of HIV-1 gp41 is targeted by broadly neutralizing antibodies (bnAbs) 4E10 and 10E8. In this proof-of-concept study, we evaluated a novel multi-immunogen vaccine strategy referred to as Incremental, Phased Antigenic Stimulation for Rapid Antibody Maturation (IPAS-RAM) to induce 4E10/10E8-like bnAbs. Rabbits were immunized sequentially, but in a phased manner, with three immunogens that are progressively more native (gp41-28×3, gp41-54CT, and rVV-gp160 DH12 ). Although nAbs were not induced, epitope-mapping analyses indicated that IPAS-RAM vaccination was better able to target antibodies towards the 4E10/10E8 epitopes than homologous prime-boost immunization using gp41-28×3 alone. MPER-specific rabbit monoclonal antibodies were generated, including 9F6. Although it lacked neutralizing activity, the target epitope profile of 9F6 closely resembled those of 4E10 and 10E8 ( 671 NWFDITNWLWYIK 683 ). B-cell repertoire analyses suggested the importance of co-immunizations for maturation of 9F6, which warrants further evaluation of our IPAS-RAM vaccine strategy using an improved priming immunogen. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. ICRF boronization. A new technique towards high efficiency wall coating for superconducting tokamak reactors

    International Nuclear Information System (INIS)

    Li Jiangang; Zhao Yan Ping; Gu Xue Mao

    1999-01-01

    A new technique for wall conditioning that will be especially useful for future larger superconducting tokamaks, such as ITER, has been successfully developed and encouraging results have been obtained. Solid carborane powder, which is non-toxic and non-explosive, was used. Pulsed RF plasma was produced by a non-Faraday shielding RF antenna with RF power of 10 kW. The ion temperature was about 2 keV with a toroidal magnetic field of 1.8 T and a pressure of 3x10 -1 Pa. Energetic ions broke up the carborane molecules, and the resulting boron ions struck and were deposited on the first wall. In comparison with glow discharge cleaning boronization, the B/C coating film shows higher adhesion, more uniformity and longer lifetime during plasma discharges. The plasma performance was improved after ICRF boronization. (author). Letter-to-the-editor

  9. First-principles calculation of the isotope effect on boron nitride nanotube thermal conductivity.

    Science.gov (United States)

    Stewart, Derek A; Savić, Ivana; Mingo, Natalio

    2009-01-01

    Isotopic composition can dramatically affect thermal transport in nanoscale heat conduits such as nanotubes and nanowires. A 50% increase in thermal conductivity for isotopically pure boron ((11)B) nitride nanotubes was recently measured, but the reason for this enhancement remains unclear. To address this issue, we examine thermal transport through boron nitride nanotubes using an atomistic Green's function transport formalism coupled with phonon properties calculated from density functional theory. We develop an independent scatterer model for (10)B defects to account for phonon isotope scattering found in natural boron nitride nanotubes. Phonon scattering from (10)B dramatically reduces phonon transport at higher frequencies and our model accounts for the experimentally observed enhancement in thermal conductivity.

  10. Synthesis and biological evaluation of boronated polyglycerol dendrimers as potential agent for neutron capture therapy

    International Nuclear Information System (INIS)

    Silva, Gerald S.; Camillo, Maria A.P.; Higa, Olga Z.; Pugliesi, Reynaldo; Fermamdes, Edson G.R.; Queiroz, Alvaro A.A. de

    2005-01-01

    In this work, the polyglycerol dendrimer (PGLD) generation 5 was used to obtain a boronated macromolecule for boron neutron capture therapy. The PGLD dendrimer was synthesized by the ring opening polymerization of deprotonated glycidol using polyglycerol as core functionality in a step-growth processes denominated divergent synthesis. The PGLD dendritic structure was confirmed by gel permeation chromatography, nuclear magnetic resonance ( 1 H-NMR, 13 C-NMR) and matrix assisted laser desorption/ionization techniques. The synthesized dendrimer presented low dispersion in molecular weights (M w /M n = 1.05) and a degree of branching of 0.82, which characterize the polymer dendritic structure. Quantitative neutron capture radiography was used to investigate the boron-10 enrichment of the polyglycerol dendrimer. The in vitro cytotoxicity to Chinese hamster ovary cells of 10 B-PGLD dendrimer indicate lower cytotoxicity, suggesting that the macromolecule is a biocompatible material. (author)

  11. Innovative boron nitride-doped propellants

    Directory of Open Access Journals (Sweden)

    Thelma Manning

    2016-04-01

    Full Text Available The U.S. military has a need for more powerful propellants with balanced/stoichiometric amounts of fuel and oxidants. However, balanced and more powerful propellants lead to accelerated gun barrel erosion and markedly shortened useful barrel life. Boron nitride (BN is an interesting potential additive for propellants that could reduce gun wear effects in advanced propellants (US patent pending 2015-026P. Hexagonal boron nitride is a good lubricant that can provide wear resistance and lower flame temperatures for gun barrels. Further, boron can dope steel, which drastically improves its strength and wear resistance, and can block the formation of softer carbides. A scalable synthesis method for producing boron nitride nano-particles that can be readily dispersed into propellants has been developed. Even dispersion of the nano-particles in a double-base propellant has been demonstrated using a solvent-based processing approach. Stability of a composite propellant with the BN additive was verified. In this paper, results from propellant testing of boron nitride nano-composite propellants are presented, including closed bomb and wear and erosion testing. Detailed characterization of the erosion tester substrates before and after firing was obtained by electron microscopy, inductively coupled plasma and x-ray photoelectron spectroscopy. This promising boron nitride additive shows the ability to improve gun wear and erosion resistance without any destabilizing effects to the propellant. Potential applications could include less erosive propellants in propellant ammunition for large, medium and small diameter fire arms.

  12. Metal-insulator transition and superconductivity in heavily boron-doped diamond and related materials

    Energy Technology Data Exchange (ETDEWEB)

    Achatz, Philipp

    2009-05-15

    During this PhD project, the metal-insulator transition and superconductivity of highly boron-doped single crystal diamond and related materials have been investigated. The critical boron concentration n{sub c} for the metal-insulator transition was found to be the same as for the normal-superconductor transition. All metallic samples have been found to be superconducting and we were able to link the occurence of superconductivity to the proximity to the metal-insulator transition. For this purpose, a scaling law approach based on low temperature transport was proposed. Furthermore, we tried to study the nature of the superconductivity in highly boron doped single crystal diamond. Raman spectroscopy measurements on the isotopically substituted series suggest that the feature occuring at low wavenumbers ({approx} 500 cm{sup -1}) is the A1g vibrational mode associated with boron dimers. Usual Hall effect measurements yielded a puzzling situation in metallic boron-doped diamond samples, leading to carrier concentrations up to a factor 10 higher than the boron concentration determined by secondary ion mass spectroscopy (SIMS). The low temperature transport follows the one expected for a granular metal or insulator, depending on the interplay of intergranular and intragranular (tunneling) conductance. The metal-insulator transition takes place at a critical conductance g{sub c}. The granularity also influences significantly the superconducting properties by introducing the superconducting gap {delta} in the grain and Josephson coupling J between superconducting grains. A peak in magnetoresistance is observed which can be explained by superconducting fluctuations and the granularity of the system. Additionally we studied the low temperature transport of boron-doped Si samples grown by gas immersion laser doping, some of which yielded a superconducting transition at very low temperatures. Furthermore, preliminary results on the LO-phonon-plasmon coupling are shown for the

  13. Front and back side SIMS analysis of boron-doped delta-layer in diamond

    Energy Technology Data Exchange (ETDEWEB)

    Pinault-Thaury, M.-A., E-mail: marie-amandine.pinault-thaury@uvsq.fr [Groupe d’Etude de la Matière Condensée, CNRS, University of Paris Saclay, University of Versailles St Quentin, 45 Avenue des Etats-Unis, 78035 Versailles Cedex (France); Jomard, F. [Groupe d’Etude de la Matière Condensée, CNRS, University of Paris Saclay, University of Versailles St Quentin, 45 Avenue des Etats-Unis, 78035 Versailles Cedex (France); Mer-Calfati, C.; Tranchant, N.; Pomorski, M.; Bergonzo, P.; Arnault, J.-C. [CEA, LIST, Diamond Sensors Laboratory, 91191 Gif-sur-Yvette (France)

    2017-07-15

    Highlights: • Front and back side SIMS analysis of delta-layer boron-doped is a first for diamond. • Combination of front and back side depth profiling improves delta-layer analyses. • Sharp interfaces are evidenced on both sides of the delta-layer boron-doped diamond. • The growth of delta-layer boron doped diamond is now well controlled. - Abstract: Nowadays the availability of very thin diamond layers in the range of nanometers as well as the possibility to characterize such delta-layer structures are required for the field of photonics and spintronics, but also for the development of next generation high power devices involving boron doping. The fabrication of diamond structures with abrupt interfaces such as superlattices and quantum wells has been recently improved. A very accurate characterization is then essential even though the analysis of such structures is arduous and challenging. SIMS analyses are commonly used to obtain depth profiles of dopants. However, below 10 nm in thickness, SIMS induced ion mixing effects which are no longer negligible. Then the raw SIMS profile might differ from the real dopant profile. In this study, we have analyzed a diamond structure containing a thin boron epilayer, especially synthesized to achieve SIMS analysis on both sides and to overcome the effects of ion mixing. We evidence the ion mixing induced by primary ions. Such a structure is a delta diamond layer, comparable to classical boron-doped delta-layer in silicon. Our results show that the growth of boron-doped delta-layer in diamond is now well controlled in terms of thickness and interfaces.

  14. Boron supplementation improves bone health of non-obese diabetic mice.

    Science.gov (United States)

    Dessordi, Renata; Spirlandeli, Adriano Levi; Zamarioli, Ariane; Volpon, José Batista; Navarro, Anderson Marliere

    2017-01-01

    Diabetes Mellitus is a condition that predisposes a higher risk for the development of osteoporosis. The objective of this study was to investigate the influence of boron supplementation on bone microstructure and strength in control and non-obese diabetic mice for 30days. The animals were supplemented with 40μg/0,5ml of boron solution and controls received 0,5ml of distilled water daily. We evaluated the biochemical parameters: total calcium, phosphorus, magnesium and boron; bone analysis: bone computed microtomography, and biomechanical assay with a three point test on the femur. This study consisted of 28 animals divided into four groups: Group water control - Ctrl (n=10), Group boron control - Ctrl±B (n=8), Group diabetic water - Diab (n=5) and Group diabetic boron - Diab±B (n=5). The results showed that cortical bone volume and the trabecular bone volume fraction were higher for Diab±B and Ctrl±B compared to the Diab and Ctrl groups (p≤0,05). The trabecular specific bone surface was greater for the Diab±B group, and the trabecular thickness and structure model index had the worst values for the Diab group. The boron serum concentrations were higher for the Diab±B group compared to non-supplemented groups. The magnesium concentration was lower for Diab and Diab±B compared with controls. The biomechanical test on the femur revealed maintenance of parameters of the bone strength in animals Diab±B compared to the Diab group and controls. The results suggest that boron supplementation improves parameters related to bone strength and microstructure of cortical and trabecular bone in diabetic animals and the controls that were supplemented. Copyright © 2016 Elsevier GmbH. All rights reserved.

  15. Effects of ball milling and sintering on alumina and alumina-boron compounds

    Science.gov (United States)

    Cross, Thomas

    Alumina has a wide variety of applications, but the processing of alumina based materials can be costly. Mechanically milling alumina has been shown to enhance the sintering properties while decreasing the sintering temperature. Additions of boron have also proven to increase sintering properties of alumina. These two processes, mechanical milling and boron additions, will be combined to test the sintering properties and determine if they are improved upon even further compared to the individual processes. Multiple samples of pure alumina, 0.2 weight percent boron, and 1.0 weight percent boron are batched and processed in a ball mill for different time intervals. These samples are then characterized to observe the structure and properties of the samples after milling but before sintering. Pellets are dry pressed from the milled powders, sintered at 1200°C for one to 10 hours, and characterized to determine the impact of processing. X-ray diffractometry (XRD) was used on each sample to determine crystallite size and lattice parameters at different stages throughout the experiment. XRD was also used to identify any samples with an aluminum borate phase. Scanning electron microscopy (SEM) was used to observe the powder and pellet morphology and to measure bulk chemical composition. Samples were sputter coated with an Au-Pd coating observed in the SEM to characterize the topography as a function of variables such as milling time, boron composition, and sintering time. Additionally, porosity and change in diameter were measured to track the sintering process. Milling sample for longer periods of time would be unnecessary due to the crystallite size leveling off between 10 and 12 hours of milling time. Samples of alumina with 0.2 weight percent boron prove to have very little effect on the sintering properties. At 1.0 weight percent boron, there are changes in diffraction patterns and topography after being sintered for one hour. The porosities of all of the sintered

  16. Intracellular boron accumulation in CHO-K1 cells using amino acid transport control

    International Nuclear Information System (INIS)

    Sato, Eisuke; Yamamoto, Tetsuya; Shikano, Naoto; Ogura, Masato; Nakai, Kei; Yoshida, Fumiyo; Uemae, Yoji; Takada, Tomoya; Isobe, Tomonori; Matsumura, Akira

    2014-01-01

    BPA used in BNCT has a similar structure to some essential amino acids and is transported into tumor cells by amino acid transport systems. Previous study groups have tried various techniques of loading BPA to increase intracellular boron concentration. CHO-K1 cells demonstrate system L (LAT1) activity and are suitable for specifying the transport system of a neutral amino acid. In this study, we examined the intracellular accumulation of boron in CHO-K1 cells by amino acid transport control, which involves co-loading with L-type amino acid esters. Intracellular boron accumulation in CHO-K1 cells showed the greatest increased upon co-loading 1.0 mM BPA, with 1.0 mM L-Tyr-O-Et and incubating for 60 min. This increase is caused by activation of a system L amino acid exchanger between BPA and L-Tyr. The amino acid esters are metabolized to amino acids by intracellular hydrolytic enzymes that increase the concentrations of intracellular amino acids and stimulate exchange transportation. We expect that this amino acid transport control will be useful for enhancing intracellular boron accumulation. - Highlights: • We examined optimal L-p-boronophenylalanine (BPA) loading in CHO-K1 cells. • Optimal BPA loading parameters were 1.0 mM and incubation for 60 min. • Intracellular boron accumulation increased upon co-loading BPA with L-Tyr-O-Et. • Optimal L-Tyr-O-Et loading parameters were 1.0 mM and incubation for 60 min. • Co-loading BPA with L-Tyr-O-Et can increase intracellular boron accumulation

  17. Aluminum and boron phosphates as possible proton conductors

    International Nuclear Information System (INIS)

    Montoneri, E.; Salzano, F.J.; Giuffre, L.

    1985-05-01

    The chemical stability and conductivity of boron and aluminum phosphates in steam are reported for P/B and P/A1 atomic ratios greater than unity at temperatures from 100 0 to 280 0 C and steam pressures to 5 atmospheres. Al(PO 3 ) 3 and H 2 A1P 3 O 10 undergo the reactions Al (PO 3 ) 3 + H 2 ) in equilibrium H 2 AlP 3 O 10 and H 2 AlP 3 O 10 → AlPO 4 + H 2 O.P 2 O 5 (g). At 280 0 C and a steam pressure of 5 atmospheres gauge the product is mixture of AlPO 4 and H 2 ALP 3 O 10 , while the conductivity of this solid is in the range of 10 -2 ohm -1 cm -1 . The boron phosphates lose material and exhibit poor conductivity under similar conditions due to the instability of the BPO 4 phase as a result of the reaction 2BPO 4 + 6 H 2 O → B 2 O 3 .3H 2 O(g) + P 2 O 5 . 3H 2 O(g). As a result of dehydration or hydrolytic reactions an increase in water vapor pressure does not always lead to increased conductivity even at higher temperature

  18. Neutron dosimetry in boron neutron capture therapy

    International Nuclear Information System (INIS)

    Fairchild, R.G.; Miola, U.J.; Ettinger, K.V.

    1981-01-01

    The recent development of various borated compounds and the utilization of one of these (Na 2 B 12 H 11 SH) to treat brain tumors in clinical studies in Japan has renewed interest in neutron capture therapy. In these procedures thermal neutrons interact with 10 B in boron containing cells through the 10 B(n,α) 7 Li reaction producing charged particles with a maximum range of approx. 10μm in tissue. Borated analogs of chlorpromazine, porphyrin, thiouracil and deoxyuridine promise improved tumor uptake and blood clearance. The therapy beam from the Medical Research Reactor in Brookhaven contains neutrons from a modified and filtered fission spectrum and dosimetric consequences of the use of the above mentioned compounds in conjunction with thermal and epithermal fluxes are discussed in the paper. One of the important problems of radiation dosimetry in capture therapy is determination of the flux profile and, hence, the dose profile in the brain. This has been achieved by constructing a brain phantom made of TE plastic. The lyoluminescence technique provides a convenient way of monitoring the neutron flux distributions; the detectors for this purpose utilize 6 Li and 10 B compounds. Such compounds have been synthesized specially for the purpose of dosimetry of thermal and epithermal beams. In addition, standard lyoluminescent phosphors, like glutamine, could be used to determine the collisional component of the dose as well as the contribution of the 14 N(n,p) 14 C reaction. Measurements of thermal flux were compared with calculations and with measurements done with activation foils

  19. Assessment of Pseudomonas aeruginosa N5,N10-methylenetetrahydrofolate dehydrogenase-cyclohydrolase as a potential antibacterial drug target.

    Directory of Open Access Journals (Sweden)

    Thomas C Eadsforth

    Full Text Available The bifunctional enzyme methylenetetrahydrofolate dehydrogenase - cyclohydrolase (FolD is identified as a potential drug target in Gram-negative bacteria, in particular the troublesome Pseudomonas aeruginosa. In order to provide a comprehensive and realistic assessment of the potential of this target for drug discovery we generated a highly efficient recombinant protein production system and purification protocol, characterized the enzyme, carried out screening of two commercial compound libraries by differential scanning fluorimetry, developed a high-throughput enzyme assay and prosecuted a screening campaign against almost 80,000 compounds. The crystal structure of P. aeruginosa FolD was determined at 2.2 Å resolution and provided a template for an assessment of druggability and for modelling of ligand complexes as well as for comparisons with the human enzyme. New FolD inhibitors were identified and characterized but the weak levels of enzyme inhibition suggest that these compounds are not optimal starting points for future development. Furthermore, the close similarity of the bacterial and human enzyme structures suggest that selective inhibition might be difficult to attain. In conclusion, although the preliminary biological data indicates that FolD represents a valuable target for the development of new antibacterial drugs, indeed spurred us to investigate it, our screening results and structural data suggest that this would be a difficult enzyme to target with respect to developing the appropriate lead molecules required to underpin a serious drug discovery effort.

  20. Determination and Standardization of Analytical Conditions for Dissolved Boron in Coastal Waters of East Sea in Korea by ICP-OES

    Science.gov (United States)

    Yoon, H.; Shin, M.; Yoon, C.; Lee, J.

    2005-12-01

    The analysis of metals in seawaters has been an important subject for many years. Achieving low-level detection limits as well as overcoming high matrix effect are requested in seawater analysis especially elements of interest are present in various chemical forms. Among them, boron is one of the widely distributed elements in nature and its concentrations of about 10 ppm in the Earth's crust and about 4.5 ppm in the seawater as borates. In seawater boron concentration exhibit a linear relationship to the amount of chloride ion present. Boron had been considered as one of the valuable elements to recover from seawaters for commercial use. Currently, we launched research team for the production of valuable metals from seawaters in Korea that can be used commercially. Several metals including boron were already under serious studies. In this study we aim to prepare standardized operational procedures in analysis of boron during pilot study for boron recovery as pilot recovery process. Inductively coupled plasma Optical Emission Spectrometry (ICP-OES) method is preferred for the analysis of the low levels of boron found in environmental samples such as seawater. In order to develop test method for the determination of dissolved Boron from East Sea Seawater in Korea, all soluble boron present in seawater has been tested and accuracy of measurement was checked from the sampling step. The result of analysis of boron in seawaters presents many difficult problems, ionization of from the alkali and alkaline earth metals. And the problems also exist in handling nebulizer and injector tubes in high saline solutions. The scope of this study was to determine boron which can contain up to 35psu dissolved salt. The work also included comparing various analytical methods for better accurate results in several solution conditions. Dilution, standard addition, matrix matching calibration methods was thoroughly tested differently and detailed operating conditions for using auxiliary

  1. Ceramic silicon-boron-carbon fibers from organic silicon-boron-polymers

    Science.gov (United States)

    Riccitiello, Salvatore R. (Inventor); Hsu, Ming-Ta S. (Inventor); Chen, Timothy S. (Inventor)

    1993-01-01

    Novel high strength ceramic fibers derived from boron, silicon, and carbon organic precursor polymers are discussed. The ceramic fibers are thermally stable up to and beyond 1200 C in air. The method of preparation of the boron-silicon-carbon fibers from a low oxygen content organosilicon boron precursor polymer of the general formula Si(R2)BR(sup 1) includes melt-spinning, crosslinking, and pyrolysis. Specifically, the crosslinked (or cured) precursor organic polymer fibers do not melt or deform during pyrolysis to form the silicon-boron-carbon ceramic fiber. These novel silicon-boron-carbon ceramic fibers are useful in high temperature applications because they retain tensile and other properties up to 1200 C, from 1200 to 1300 C, and in some cases higher than 1300 C.

  2. Enhanced diffusion of boron by oxygen precipitation in heavily boron-doped silicon

    Science.gov (United States)

    Torigoe, Kazuhisa; Ono, Toshiaki

    2017-06-01

    The enhanced diffusion of boron has been investigated by analyzing out-diffusion profiles in the vicinity of the interface between a lightly boron-doped silicon epitaxial layer and a heavily boron-doped silicon substrate with a resistivity of 8.2 mΩ cm and an oxide precipitate (O.P.) density of 108-1010 cm-3. It is found that the boron diffusion during annealing at 850-1000 °C is enhanced with the increase of the oxide precipitate density. On the basis of a model for boron diffusion mediated by silicon self-interstitials, we reveal that the enhanced diffusion is attributed to self-interstitials supersaturated as a result of the emission from oxide precipitates and the absorption by punched-out dislocations. In addition, the temperature dependence of the fraction of the self-interstitial emission obtained analyzing the diffusion enhancement well explains the morphology changes of oxide precipitates reported in literature.

  3. Modeling of the hot flow behavior of advanced ultra-high strength steels (A-UHSS) microalloyed with boron

    Energy Technology Data Exchange (ETDEWEB)

    Mejía, I., E-mail: imejia@umich.mx [Instituto de Investigaciones Metalúrgicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio “U”, Ciudad Universitaria, 58066 Morelia, Michoacán (Mexico); Altamirano, G.; Bedolla-Jacuinde, A. [Instituto de Investigaciones Metalúrgicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio “U”, Ciudad Universitaria, 58066 Morelia, Michoacán (Mexico); Cabrera, J.M. [Departament de Ciència dels Materials i Enginyeria Metallúrgica, ETSEIB – Universitat Politècnica de Catalunya, Av. Diagonal 647, 08028 Barcelona (Spain); Fundació CTM Centre Tecnològic, Av. de las Bases de Manresa, 1, 08240 Manresa (Spain)

    2014-07-29

    In this research work, modeling of the hot flow behavior was carried out in a low carbon advanced ultra-high strength steels (A-UHSS) microalloyed with different amounts of boron (14, 33, 82, 126 and 214 ppm). For this purpose, experimental stress–strain data of uniaxial hot-compression tests over a wide range of temperatures (1223, 1273, 1323 and 1373 K (950, 1000, 1050 and 1100 °C)) and strain rates (10{sup −3}, 10{sup −2} and 10{sup −1} s{sup −1}) were used. The stress–strain relationships as a function of temperature and strain rate were successfully described on the basis of the approach proposed by Estrin, Mecking, and Bergström, together with the classical Avrami equation and the conventional hyperbolic sine function. The analysis of the modeling parameters of the hot flow curves shows that boron additions to A-UHSS play a major role in softening mechanisms rather than on hardening. The peak stress (σ{sub p}) and steady-state stress (σ{sub ss}) values show a decreasing trend with increasing boron content, which indicates that boron additions promote a solid solution softening effect additional to that produced by DRX. The time for 50% recrystallization (t{sub 50%}) tends to increase with boron additions, revealing that boron additions cause a delay of the DRX kinetics during hot deformation. Similarly, the presence of boron in the steel decreases the apparent activation energy for recrystallization (Q{sub t}), indicating that boron additions accelerate the onset of DRX. The constitutive equations developed in this way provided an excellent description of the experimental hot flow curves.

  4. Nanotechnology of emerging targeting systems.

    Science.gov (United States)

    Smith, S S

    2008-09-01

    Recent developments in the design and testing of complex nanoscale payload-carrying systems (i.e. systems with payloads that do not exceed 100 nm in size) are the focus of this brief review. Emerging systems include targeted single-walled nanotubes, viral capsids, dendrimers, gold nanoparticles, milled boron carbide nanoparticles, and protein nucleic acid assemblies. Significant advances are emerging with each of these bionanotechnological approaches to cellular targeting.

  5. Atmospheric contribution to boron enrichment in aboveground wheat tissues.

    Science.gov (United States)

    Wang, Cheng; Ji, Junfeng; Chen, Mindong; Zhong, Cong; Yang, Zhongfang; Browne, Patrick

    2017-05-01

    Boron is an essential trace element for all organisms and has both beneficial and harmful biological functions. A particular amount of boron is discharged into the environment every year because of industrial activities; however, the effects of environmental boron emissions on boron accumulation in cereals has not yet been estimated. The present study characterized the accumulation of boron in wheat under different ecological conditions in the Yangtze River Delta (YRD) area. This study aimed to estimate the effects of atmospheric boron that is associated with industrial activities on boron accumulation in wheat. The results showed that the concentrations of boron in aboveground wheat tissues from the highly industrialized region were significantly higher than those from the agriculture-dominated region, even though there was no significant difference in boron content in soils. Using the model based on the translocation coefficients of boron in the soil-wheat system, we estimated that the contribution of atmosphere to boron accumulation in wheat straw in the highly industrialized region exceeded that in the agriculture-dominated region by 36%. In addition, from the environmental implication of the model, it was estimated that the development of boron-utilizing industries had elevated the concentration of boron in aboveground wheat tissues by 28-53%. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Comparison of Levelized Cost of Energy of a 10 MW superconducting and magnetic pseudo direct drive generator targeted for the INNWIND.EU reference turbine

    NARCIS (Netherlands)

    Abrahamsen, Asger Bech; Liu, D.; Magnusson, Niklas; Thomas, A; Z., Azar; Stehouwer, Ewoud; Hendriks, E; Penzkofer, A.; Atallah, K; Dragan, R.R.; .Clark, R.E.; Deng, F.; Chen, Z; Karwatzki, D.; Mertens, A.; Parker, M; Finney, SJ; Polinder, H.

    2017-01-01

    Innovative drive trains targeted at 10-20 MW offshore turbines are investigated in the INNWIND.EU project in order to determine the impact on the Levelized Cost of Energy (LCoE) resulting when installed in the ,North sea at 50 m of water [1]. The two main technologies studied are superconducting

  7. Target virus log10 reduction values determined for two reclaimed wastewater irrigation scenarios in Japan based on tolerable annual disease burden.

    Science.gov (United States)

    Ito, Toshihiro; Kitajima, Masaaki; Kato, Tsuyoshi; Ishii, Satoshi; Segawa, Takahiro; Okabe, Satoshi; Sano, Daisuke

    2017-11-15

    Multiple-barriers are widely employed for managing microbial risks in water reuse, in which different types of wastewater treatment units (biological treatment, disinfection, etc.) and health protection measures (use of personal protective gear, vegetable washing, etc.) are combined to achieve a performance target value of log 10 reduction (LR) of viruses. The LR virus target value needs to be calculated based on the data obtained from monitoring the viruses of concern and the water reuse scheme in the context of the countries/regions where water reuse is implemented. In this study, we calculated the virus LR target values under two exposure scenarios for reclaimed wastewater irrigation in Japan, using the concentrations of indigenous viruses in untreated wastewater and a defined tolerable annual disease burden (10 -4 or 10 -6 disability-adjusted life years per person per year (DALY pppy )). Three genogroups of norovirus (norovirus genogroup I (NoV GI), geogroup II (NoV GII), and genogroup IV (NoV GIV)) in untreated wastewater were quantified as model viruses using reverse transcription-microfluidic quantitative PCR, and only NoV GII was present in quantifiable concentration. The probabilistic distribution of NoV GII concentration in untreated wastewater was then estimated from its concentration dataset, and used to calculate the LR target values of NoV GII for wastewater treatment. When an accidental ingestion of reclaimed wastewater by Japanese farmers was assumed, the NoV GII LR target values corresponding to the tolerable annual disease burden of 10 -6 DALY pppy were 3.2, 4.4, and 5.7 at 95, 99, and 99.9%tile, respectively. These percentile values, defined as "reliability," represent the cumulative probability of NoV GII concentration distribution in untreated wastewater below the corresponding tolerable annual disease burden after wastewater reclamation. An approximate 1-log 10 difference of LR target values was observed between 10 -4 and 10 -6 DALY pppy

  8. Effects of boron supplementation on the severity and duration of pain in primary dysmenorrhea.

    Science.gov (United States)

    Nikkhah, Somayeh; Dolatian, Mahrokh; Naghii, Mohammad Reza; Zaeri, Farid; Taheri, Seyed Mojtaba

    2015-05-01

    Primary dysmenorrhea refers to painful menstrual cramps without pelvic pathology. The condition is highly prevalent among women and exerts negative effects on their quality of life. Considering the evidence for anti-inflammatory properties of Boron, the present study aimed to determine the effects of Boron supplementation on the severity and duration of menstrual pain in female university students. This triple-blind randomized clinical trial study recruited 113 university students. The participants were matched for the severity and duration of dysmenorrhea and randomly allocated into the case and control groups (n = 58 and 55, respectively). The case group consumed 10 mg/day Boron from two days before the menstrual flow until its third day. The control group received placebo capsules (similar to those distributed among the cases). All subjects were asked to take the capsules for two consecutive menstrual cycles. Pain severity (measured on a visual analog scale) and duration (in hours) were measured at baseline and during the two cycles. The two groups had no significant differences in the severity and duration of pain at baseline. After the intervention, however, the severity and duration of pain were significantly lower in the case group than in the control group (P Boron supplementation can reduce the severity and duration of menstrual pain through exerting anti-inflammatory effects. In order to clarify the effects of Boron on dysmenorrhea, future studies are required to measure the levels of hormones and inflammatory biomarkers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Boron isotopic composition of tourmaline from massive sulfide deposits and tourmalinites

    Science.gov (United States)

    Palmer, M.R.; Slack, J.F.

    1989-01-01

    Boron isotope ratios (11B/10B) have been measured on 60 tourmaline separates from over 40 massive sulfide deposits and tourmalinites from a variety of geologic and tectonic settings. The coverage of these localities is global (5 continents) and includes the giant ore bodies at Kidd Creek and Sullivan (Canada), Broken Hill (Australia), and Ducktown (USA). Overall, the tourmalines display a wide range in ??11B values from -22.8 to +18.3??? Possible controls over the boron isotopic composition of the tourmalines include: 1) composition of the boron source, 2) regional metamorphism, 3) water/rock ratios, 4) seawater entrainment, 5) temperature of formation, and 6) secular variations in seawater ??11B. The most significant control appears to be the composition of the boron source, particularly the nature of footwall lithologies; variations in water/ rock ratios and seawater entrainment are of secondary importance. The boron isotope values seem especially sensitive to the presence of evaporites (marine and non-marine) and carbonates in source rocks to the massive sulfide deposits and tourmalinites. ?? 1989 Springer-Verlag.

  10. Study of boron distribution in silicon structure by side long section technique

    International Nuclear Information System (INIS)

    Kadirova, M.; Zhumaev, N.; Simakhin, Yu.F.; Usmanova, M.M.

    1997-01-01

    To study deep boron diffusion in the complex silicon structures, consisting of interchange boron doping layers of mono- and polycrystalline silicon, separated by oxide films a technique of side long section by using Solid State Nuclear Track Detector (SSNTD) has been elaborated. The boron distribution technique is based on the detection of alpha-particles from the 10 B(n,α) 7 Li reaction with cellulose nitrate film. The etched α-track registering cellulose nitrite film show the structure image magnified 1/sinφ fold. Boron concentration defined by density of the etched pits appearing on the film surface. An optical microscope analysis of the sample track-mapping image is realised by examination with closely spaced (Δl < Δx/sinφ) and largely spaced (Δl ≥ Δx/sinφ) movements. For analysis of both experimental data the computer application programs have been developed. An universal algorithm for determination of the boron profiles has been created to take into account influence of a deeper layers on a total measurement of track density when Δl < Δx/sinφ. (author)

  11. Summary Report of Depleted Uranium (DU) Survey Actions at Nevada Test and Training Range (NTTR), Airspace Region 63B, Active Target Complex 10 (63-10)

    Science.gov (United States)

    2016-09-15

    AND ADDRESS(ES) USAF School of Aerospace Medicine Occupational & Environmental Health Dept/OEC 2510 Fifth St. Wright-Patterson AFB, OH 45433-7913... Medicine (USAFSAM), dose rate, count rate, bioenvironmental engineering, permit, depleted uranium, DU, GAU-8, A-10, Nevada, Nellis, NTTR, testing range, U...AFIERA, AFIOH, ACC , GR-460, RS-700, Model 2221, surveillance, walkover, aerosol, sampling, drainage, GPS 16. SECURITY CLASSIFICATION OF: 17

  12. 15th International Conference on Boron Chemistry (IMEBORON XV)

    Czech Academy of Sciences Publication Activity Database

    Grüner, Bohumír; Štíbr, Bohumil

    2015-01-01

    Roč. 87, č. 2 (2015), s. 121 ISSN 0033-4545 Institutional support: RVO:61388980 Keywords : boranes * boron * boron materials * carboranes * IMEBORON XV * medicinal chemistry Subject RIV: CA - Inorganic Chemistry

  13. Removal of boron from aqueous solution using cryptocrystalline magnesite

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2016-05-01

    Full Text Available The present study aimed to evaluate the efficiency of using cryptocrystalline magnesite to remove boron ions from aqueous systems. Batch experimental protocols were used to evaluate the adsorption capacity of magnesite for boron. Parameters...

  14. Boron: out of the sky and onto the ground

    International Nuclear Information System (INIS)

    Kuehl, D.K.

    1975-01-01

    Now an accepted, engineered material for aerospace applications, boron is taking its place on the ground. Both current production applications, prototype (development) applications, and speculative applications abound. In the leisure product market, boron epoxy or boron aluminum has been used or tried in golf clubs (in combination with graphite epoxy or to reinforce aluminum or steel), in tennis racquets, in bicycles, racing shells, skis and skipoles, bows and arrows, and others. In the industrial area, boron has been used to reduce fatigue, increase stiffness, or for its abrasive properties. Textile machinery, honing tools, and cut off wheels or saws are among the applications. In the medical field, prosthetics and orthotic braces, wheel chairs, canes, and crutches are all good applications for boron. Applications for boron in transportation, construction, and heavy industry are also possible. The volume of boron used in these applications could have a major impact on prices, making boron composite parts cost competitive with conventional materials. (U.S.)

  15. Method of manufacture of atomically thin boron nitride

    Science.gov (United States)

    Zettl, Alexander K

    2013-08-06

    The present invention provides a method of fabricating at least one single layer hexagonal boron nitride (h-BN). In an exemplary embodiment, the method includes (1) suspending at least one multilayer boron nitride across a gap of a support structure and (2) performing a reactive ion etch upon the multilayer boron nitride to produce the single layer hexagonal boron nitride suspended across the gap of the support structure. The present invention also provides a method of fabricating single layer hexagonal boron nitride. In an exemplary embodiment, the method includes (1) providing multilayer boron nitride suspended across a gap of a support structure and (2) performing a reactive ion etch upon the multilayer boron nitride to produce the single layer hexagonal boron nitride suspended across the gap of the support structure.

  16. Effect of low level doping of boron and phosphorus on the properties of amorphous silicon films

    International Nuclear Information System (INIS)

    Tran, N.T.; Epstein, K.A.; Grimmer, D.P.; Vernstrom, G.D.

    1987-01-01

    Effect of the low level doping of boron and phosphorus on the properties of amorphous silicon films (a-Si:H) were studied. Doping level of both boron and phosphorus was in the range of 10/sup 17/ atoms/cm/sup 3/. Apparent improvement in the stability of dark and photoconductivity of a-Si: films upon low level doping does not result from the elimination of light-induced defects. The stability of the dark and photoconductivity upon doping is an indication of pinning of the Fermi level

  17. Improvements in Boron Plate Coating Technology for Higher Efficiency Neutron Detection and Coincidence Counting Error Reduction

    Energy Technology Data Exchange (ETDEWEB)

    Menlove, Howard Olsen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Henzlova, Daniela [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-25

    This informal report presents the measurement data and information to document the performance of the advanced Precision Data Technology, Inc. (PDT) sealed cell boron-10 plate neutron detector that makes use of the advanced coating materials and procedures. In 2015, PDT changed the boron coating materials and application procedures to significantly increase the efficiency of their basic corrugated plate detector performance. A prototype sealed cell unit was supplied to LANL for testing and comparison with prior detector cells. Also, LANL had reference detector slabs from the original neutron collar (UNCL) and the new Antech UNCL with the removable 3He tubes. The comparison data is presented in this report.

  18. Superconductivity in boron carbide? Clarification by low-temperature MIR/FIR spectra.

    Science.gov (United States)

    Werheit, H; Kuhlmann, U

    2011-11-02

    The electronic structure and phonon density of B(13)B(2) boron carbide calculated by Calandra et al (2004 Phys. Rev. B 69 224505) defines this compound as metallic, and the authors predict superconductivity with T(C)s up to 36.7 K. Their results are affected by the same deficiencies as former band structure calculations on boron carbides based on hypothetical crystal structures deviating significantly from the real ones. We present optical mid IR/far IR (MIR/FIR) spectra of boron carbide with compositions between B(4.3)C and B(10.37)C, evidencing semiconducting behaviour at least down to 30 K. There is no indication of superconductivity. The spectra yield new information on numerous localized gap states close to the valence band edge.

  19. Reduction of hydrogen content in boron film by controlling glow discharge conditions

    Science.gov (United States)

    Natsir, M.; Sagara, A.; Motojima, O.

    1995-04-01

    Reducing the hydrogen content in boron films produced with DC glow discharge was first investigated at room temperature in plasma processing teststand (PPT) by measuring dependences on B 10H 14 flow rate, mixing ratio in helium, discharge power, and total pressure. The experimental condition during boronization was monitored using Langmuir probe. The hydrogen concentration was analyzed by using an in situflash-filament desorption method. Results show that a high growth rate of film formation and high pumping speed are effective in reducing hydrogen concentration. This new finding is applicable to reduce hydrogen recycling from boronized walls in present day plasma machines which cannot use high temperature baking over 100°C.

  20. Target Practice: Reader Response Theory and Teachers' Interpretations of Students' SAT 10 Scores in Data-Based Professional Development

    Science.gov (United States)

    Atkinson, Becky M.

    2012-01-01

    The study reported in this article examines how teachers read and respond to their students' Stanford Achievement Test 10 (SAT 10) scores with the goal of investigating the assumption that data-based teaching practice is more "objective" and less susceptible to divergent teacher interpretation. The study uses reader response theory to…

  1. Myostatin gene knockout mediated by Cas9-D10A nickase in chicken DF1 cells without off-target effect

    Directory of Open Access Journals (Sweden)

    Jeong Hyo Lee

    2017-05-01

    Full Text Available Objective Based on rapid advancement of genetic modification techniques, genomic editing is expected to become the most efficient tool for improvement of economic traits in livestock as well as poultry. In this study, we examined and verified the nickase of mutated CRISPR-associated protein 9 (Cas9 to modulate the specific target gene in chicken DF1 cells. Methods Chicken myostatin which inhibits muscle cell growth and differentiation during myogenesis was targeted to be deleted and mutated by the Cas9-D10A nickase. After co-transfection of the nickase expression vector with green fluorescent gene (GFP gene and targeted multiplex guide RNAs (gRNAs, the GFP-positive cells were sorted out by fluorescence-activated cell sorting procedure. Results Through the genotyping analysis of the knockout cells, the mutant induction efficiency was 100% in the targeted site. Number of the deleted nucleotides ranged from 2 to 39 nucleotide deletion. There was no phenotypic difference between regular cells and knockout cells. However, myostatin protein was not apparently detected in the knockout cells by Western blotting. Additionally, six off-target sites were predicted and analyzed but any non-specific mutation in the off-target sites was not observed. Conclusion The knockout technical platform with the nickase and multiplex gRNAs can be efficiently and stablely applied to functional genomics study in poultry and finally adapted to generate the knockout poultry for agribio industry.

  2. Synthesis, characterization and spectroscopic studies of some boron-containing hydrogen storage materials

    Science.gov (United States)

    Jash, Panchatapa

    In this dissertation the synthesis and characterization of boron-related nanostructures and dehydrogenation studies of metal borohydrides using FTIR are reported. Boron-related nanostructures are of interest because of their potential applications in nanoelectronics and in hydrogen storage. A low pressure chemical vapor deposition (LPCVD) apparatus was built in order to grow boron nanostructures. Various techniques, namely, Auger electron spectroscopy (AES), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy were used to characterize the synthesized boron and boride nanostructures, and boron coated carbon nanotubes (CNTs). By the uncatalyzed pyrolysis of diborane, at relatively low temperature, crystalline boron nanoribbons were synthesized. Nickel-catalyzed growth also produced Ca, Sr and Y boride nanowires that were found to be crystalline. Amorphous boron coated CNTs were synthesized by LPCVD. Two growth mechanisms, vapor-liquid-solid (VLS) and vapor-solid (VS) were invoked to explain the observed nanostructures. A high vacuum apparatus for FTIR studies was built. The capabilities of the apparatus were first tested by acquiring low temperature and room temperature spectra of sodium and lithium borohydrides. The metal borohydrides are of high hydrogen content and dehydrogenation studies using FTIR were done. NaBH 4 and the K2B12H12 salt were studied. It was found that above its melting point (673 K), NaBH4 is probably converted to its B12H12-2 salt, which then loses all hydrogen to produce amorphous boron. This conversion of B 12H12-2 to boron clusters was confirmed through dehydrogenation studies of K2B12H12. Both SIMS and AES are surface sensitive techniques to study thin film surfaces and interfaces at nano-dimentions. Thin (9-10 mum) cadmium telluride films have application as the buffer layer on silicon substrates to form high

  3. Effect of thermal and thermo-mechanical cycling on the boron segregation behavior in the coarse-grained heat-affected zone of low-alloy steel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sanghoon; Kang, Yongjoon; Lee, Changhee, E-mail: chlee@hanyang.ac.kr

    2016-06-15

    The boron segregation behavior in the coarse-grained heat-affected zone (CGHAZ) of 10 ppm boron-added low-alloy steel during the welding cycle was investigated by taking the changes in the microstructure and hardness into account. Various CGHAZs were simulated with a Gleeble system as a function of the heat input and external stress, and the boron segregation behavior was analyzed by secondary ion mass spectrometry (SIMS) and particle tracking autoradiography (PTA). The segregation of boron was found to initially increase, and then decrease with an increase in the heat input. This is believed to be due to the back-diffusion of boron with an increase in the exposure time at high temperature after non-equilibrium grain boundary segregation. The grain boundary segregation of boron could be decreased by an external stress applied during the welding cycle. Such behavior may be due to an increase in the grain boundary area as a result of the grain size reduction induced by the external stress. - Highlights: • Boron segregation behavior in the CGHAZ of low-alloy steel during a welding cycle was investigated. • Various CGHAZs were simulated with a Gleeble system as a function of the heat input and external stress. • Boron segregation behavior was analyzed using SIMS and PTA techniques.

  4. Characterization of boron carbide with an electron microprobe

    Science.gov (United States)

    Matteudi, G.; Ruste, J.

    1983-01-01

    Within the framework of a study of heterogeneous materials (Matteudi et al., 1971: Matteudi and Verchery, 1972) thin deposits of boron carbide were characterized. Experiments using an electronic probe microanalyzer to analyze solid boron carbide or boron carbide in the form of thick deposits are described. Quantitative results on boron and carbon are very close to those obtained when applying the Monte Carlo-type correction calculations.

  5. Impact scenarios in boron carbide: A computational study

    OpenAIRE

    Bell, R. G.; Sugden, I. J.; Plant, D. F.

    2016-01-01

    The effect of radiative impacts on the structure of boron carbide has been studied by both classical and ab initio simulations. As a part of this study, a new forcefield was developed for use in studying boron carbide materials. Impact scenarios in boron carbide were simulated in order to investigate the exceptional resistance of this material, and other icosahedral boron solids, to high-energy impact events. It was observed that interstitial defects created by radiative impacts are likely to...

  6. Technology of boron-containing polyphosphate fertilizer 'Phosphobor'

    International Nuclear Information System (INIS)

    Aldabergenov, M.K.; Balakaeva, T.G.

    1995-01-01

    A technology is developed for producing 'Phosphobor' fertilizer based on the rock phosphate weal (17-18% P 2 O 5 ) with additions of boron-magnesium compound. Boron is part of polyphosphate fertilizer in the form of polymeric compounds of phosphorus and boron. Phosphorus and boron copolymers -boratophosphates - are easily formed in the process of polyphosphate fertilizers production, since borates undergo a mutual polycondensation reaction with phosphates. 8 refs., 1 fig

  7. Determination of free carbon content in boron carbide ceramic powders

    International Nuclear Information System (INIS)

    Castro, A.R.M. de; Lima, N.B. de; Paschoal, J.O.A.

    1990-01-01

    Boron carbide is a ceramic material of technological importance due to its hardness and high chemical and thermal stabilities. Free carbon is always found as a process dependent impurity in boron carbide. The development of procedures for its detection is required because its presence leads to a degradation of the boron carbide properties. In this work, several procedures for determining free carbon content in boron carbide specimens are reported and discussed for comparison purposes. (author) [pt

  8. Structure of boron carbide after applying shear deformations under a pressure to 55 GPa

    Science.gov (United States)

    Annenkov, M. R.; Kulnitskiy, B. A.; Perezhogin, I. A.; Ovsyannikov, D. A.; Popov, M. Yu.; Blank, V. D.

    2017-05-01

    Transmission electron microscopy has been used to study the structural features of boron carbide treated in a high-pressure shear chamber with diamond anvils in the pressure range 25-55 GPa. Such a treatment has been shown to lead to the predominant crack formation along planes {10 11 } and {10 12} and also the formation of polytypes in the {10 11} planes and strain bands in the {10 12} planes.

  9. Boron-Loaded Silicone Rubber Scintillators

    CERN Document Server

    Bell, Z W; Maya, L; Sloop, F V J

    2003-01-01

    Silicone rubber received attention as an alternative to polyvinyltoluene in applications in which the scintillator is exposed to high doses because of the increased resistance of the rubber to the formation of blue-absorbing color centers. Work by Bowen, et al., and Harmon, et al., demonstrated their properties under gamma/x-ray irradiation, and Bell, et al. have shown their response to thermal neutrons. This last work, however, provided an example of a silicone in which both the boron and the scintillator were contained in the rubber as solutes, a formulation which led to the precipitation of solids and sublimation of the boron component. In the present work we describe a scintillator in which the boron is chemically bonded to the siloxane and so avoids the problem of precipitation and loss of boron to sublimation. Material containing up to 18% boron, by weight, was prepared, mounted on photomultipliers, and exposed to both neutron and gamma fluxes. Pulse height spectra showing the neutron and photon respons...

  10. Hot ductility behavior of boron microalloyed steels

    International Nuclear Information System (INIS)

    Lopez-Chipres, E.; Mejia, I.; Maldonado, C.; Bedolla-Jacuinde, A.; Cabrera, J.M.

    2007-01-01

    The current study analyses the influence of boron contents (between 29 and 105 ppm) on the hot ductility of boron microalloyed steels. For this purpose, hot tensile tests were carried out at different temperatures (700, 800, 900 and 1000 deg. C) at a constant true strain rate of 0.001 s -1 . In general, results revealed an improvement of the hot ductility of steels at increasing boron content. At 700, 900 and 1000 deg. C the ductility is higher than at 800 deg. C, where boron microalloyed steels exhibit a region of ductility loss (trough region). Likewise, dynamic recrystallization only occurred at 900 and 1000 deg. C. The fracture surfaces of the tested steels at temperatures giving the high temperature ductility regime show that the fracture mode is a result of ductile failure, whereas it is ductile-brittle failure in the trough region. Results are discussed in terms of dynamic recrystallization and boron segregation towards austenite grain boundaries, which may retard the formation of pro-eutectoid ferrite and increase grain boundary cohesion

  11. T-cell activation is enhanced by targeting IL-10 cytokine production in toll-like receptor- stimulated macrophages

    Directory of Open Access Journals (Sweden)

    Walk RM

    2012-11-01

    Full Text Available Ryan M Walk,1,2 Steven T Elliott,2 Felix C Blanco,2 Jason A Snyder,2 Ashley M Jacobi,3 Scott D Rose,3 Mark A Behlke,3 Aliasger K Salem,4 Stanislav Vukmanovic,2 Anthony D Sandler21Department of Surgery, Walter Reed Army Medical Center, Washington, DC, USA; 2Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Medical Center, Washington, DC, USA; 3Integrated DNA Technologies, Coralville, IA, USA; 4Division of Pharmaceutics, University of Iowa, Iowa City, IA, USAAbstract: Toll-like receptor (TLR agonists represent potentially useful cancer vaccine adjuvants in their ability to stimulate antigen-presenting cells (APCs and subsequently amplify the cytotoxic T-cell response. The purpose of this study was to characterize APC responses to TLR activation and to determine the subsequent effect on lymphocyte activation. We exposed murine primary bone marrow-derived macrophages to increasing concentrations of agonists to TLRs 2, 3, 4, and 9. This resulted in a dose-dependent increase in production of not only tumor necrosis factor–alpha (TNF-α, a surrogate marker of the proinflammatory response, but also interleukin 10 (IL-10, a well-described inhibitory cytokine. Importantly, IL-10 secretion was not induced by low concentrations of TLR agonists that readily produced TNF-α. We subsequently stimulated lymphocytes with anti-CD3 antibody in the presence of media from macrophages activated with higher doses of TLR agonists and observed suppression of interferon gamma release. Use of both IL-10 knockout macrophages and IL-10 small-interfering RNA (siRNA ablated this suppressive effect. Finally, IL-10 siRNA was successfully used to suppress CpG-induced IL-10 production in vivo. We conclude that TLR-mediated APC stimulation can induce a paradoxical inhibitory effect on T-cell activation mediated by IL-10.Keywords: toll-like receptors, innate immunity, IL-10

  12. Boron Affects Immune Function Through Modulation of Splenic T Lymphocyte Subsets, Cytokine Secretion, and Lymphocyte Proliferation and Apoptosis in Rats.

    Science.gov (United States)

    Jin, Erhui; Li, Shenghe; Ren, Man; Hu, Qianqian; Gu, Youfang; Li, Kui

    2017-08-01

    This study demonstrated the mechanisms of boron effects in a rat model and provided a scientific basis for the rational of boron use. These findings were achieved by investigating the effects of boron (10, 20, 40, 80, 160, 320, and 640 mg/L in drinking water or 1.5, 3, 6, 12, 24, 48, and 96 mg/kg BW) on rat serum immunoglobulins (IgGs), splenic cytokines, lymphocyte subsets, as well as on lymphocyte proliferation and apoptosis. Addition of 20 (3) and 40 (6) mg/L (mg/kg BW) of boron to drinking water significantly increased rat serum IgG concentrations, splenic IFN-γ and IL-4 expression as well as the number of splenic CD3 + , CD4 + and proliferating cell nuclear antigen (PCNA) + cells. Supplementation of drinking water with 40 mg/L (6 mg/kg BW) boron also markedly increased splenic IL-2 expression and the CD4 + /CD8 + cell ratio and reduced splenic CD8 + cell number. Supplementation with 80 mg/L (12 mg/kg BW) boron significantly increased CD3 + and PCNA + cell numbers (P boron markedly reduced the serum IgG concentrations; splenic IL-2 and IL-10 expression; the number of CD3 + , CD4 + and PCNA + cells; and increased the number of splenic CD8 + and caspase-3 + cells and promoted caspase-3 expression in CD3 + cells. In conclusion, these findings suggest that the supplementation of rat drinking water with 20(3) and 40(6) mg/L (mg/kg BW) boron can markedly enhance humoral and cellular immune functions, while boron concentrations above 320 mg/L (48 mg/kg BW) can have an inhibitory effect or even toxicity on immune functions. These results exhibit a U-shaped response characteristic of low and high doses of boron supplementation on immune function and imply that proper boron supplementation in food for humans and animals could be used as an immunity regulator.

  13. Adsorption Isotherms of Boron in Soil: the effects of Sodium Adsorption Ratio (SAR, pH and Ionic strength

    Directory of Open Access Journals (Sweden)

    Mojtaba Moqbeli

    2017-03-01

    Full Text Available Introduction: Boron (B is an essential plant micronutrient whose soil availability is influenced by many soil factors.Understanding the processes controling activity of boron (B in the soil solution is important for soil fertility management. The reaction of adsorption and desorption of boron in soil determines the amount of boron that is available to plants. Adsorption–desorption processes play a major role on boron equilibrium concentration and therefore on its bio-availability. Ionic strength, pH and ionic composition in exchangeable phase are among themajor factors affecting B adsorption reactions.Reducedadsorption of boron at high pH is because of a surface potential decrease onminerals with pH-dependent charge. Ionic strength has also a considerable effect on B adsorption.Several studies have been performed inthe adsorption of boron and the effect of factors such as ionicstrength and cations has been understudied, however, the effect of sodium adsorption ratio and itsinteraction with the ionic strength on boron adsorption behavior has not been reported. In thisstudy, the adsorption isotherms of boron in the soils affected by the combined effects of ionic strengthand sodium adsorption ratio were investigated. Materials and Methods: In order to assess the effects of ionic strength (IS and Sodium Adsorption Ratio (SAR on availability of B, the adsorption of B was investigated in a calcareous soil that hadlow levels of electrical conductivity, sodium adsorption ratio and available P. For this purpose, 5 g soil wasequilibrated with 20 mL of B solution (0, 2, 5, 8, 10, 15, 20 mg L-1 in 0.02, 0.06 and 0.12 M background solutions (prepared by NaC1,CaC12.2H2O, MgCl2.6H2O, at two SAR levels (20 and 100.The reaction temperature was 25◦C. The suspension was centrifuged, filtered, and a sample was removed and B was determined by Azomethine-H spectrophotometric method (at a wavelength of 420 nm. B adsorption in Soil was obtained by subtracting B in

  14. Encapsulation of cisplatin as an anti-cancer drug into boron-nitride and carbon nanotubes: Molecular simulation and free energy calculation

    Energy Technology Data Exchange (ETDEWEB)

    Roosta, Sara [Molecular Simulation Research Laboratory, Department of Chemistry, Iran University of Science & Technology, Tehran (Iran, Islamic Republic of); Hashemianzadeh, Seyed Majid, E-mail: hashemianzadeh@iust.ac.ir [Molecular Simulation Research Laboratory, Department of Chemistry, Iran University of Science & Technology, Tehran (Iran, Islamic Republic of); Ketabi, Sepideh, E-mail: sepidehketabi@yahoo.com [Department of Chemistry, East Tehran Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)

    2016-10-01

    Encapsulation of cisplatin anticancer drug into the single walled (10, 0) carbon nanotube and (10, 0) boron-nitride nanotube was investigated by quantum mechanical calculations and Monte Carlo Simulation in aqueous solution. Solvation free energies and complexation free energies of the cisplatin@ carbon nanotube and cisplatin@ boron-nitride nanotube complexes was determined as well as radial distribution functions of entitled compounds. Solvation free energies of cisplatin@ carbon nanotube and cisplatin@ boron-nitride nanotube were − 4.128 kcal mol{sup −1} and − 2457.124 kcal mol{sup −1} respectively. The results showed that cisplatin@ boron-nitride nanotube was more soluble species in water. In addition electrostatic contribution of the interaction of boron- nitride nanotube complex and solvent was − 281.937 kcal mol{sup −1} which really more than Van der Waals and so the electrostatic interactions play a distinctive role in the solvation free energies of boron- nitride nanotube compounds. On the other hand electrostatic part of the interaction of carbon nanotube complex and solvent were almost the same as Van der Waals contribution. Complexation free energies were also computed to study the stability of related structures and the free energies were negative (− 374.082 and − 245.766 kcal mol{sup −1}) which confirmed encapsulation of drug into abovementioned nanotubes. However, boron-nitride nanotubes were more appropriate for encapsulation due to their larger solubility in aqueous solution. - Highlights: • Solubility of cisplatin@ boron-nitride nanotube is larger than cisplatin@ carbon nanotube. • Boron- nitride nanotube complexes have larger electrostatic contribution in solvation free energy. • Complexation free energies confirm encapsulation of drug into the nanotubes in aqueous solution. • Boron- nitride nanotubes are appropriate drug delivery systems compared with carbon nanotubes.

  15. INFLUENCE OF FINE-DISPERSED BORON CARBIDE ON THE STRUCTURE AND CHARACTERISTICS OF IRON-BORON ALLOY

    Directory of Open Access Journals (Sweden)

    N. F. Nevar

    2010-01-01

    Full Text Available The influence of boron carbide as fine-dispersed material input into the melt on structure morphology, founding, technological and exploitation characterisstics of cast iron-boron material is shown.

  16. Simulating the effect of boron doping in superconducting carbon

    Science.gov (United States)

    Sakai, Yuki; Chelikowsky, James R.; Cohen, Marvin L.

    2018-02-01

    We examine the effect of boron doping in superconducting forms of amorphous carbon. By judiciously optimizing boron substitutional sites in simulated amorphous carbon, we predict a superconducting transition temperature near 37 K at 14% boron concentration. Our findings have direct implications for understanding the recently discovered high-Tc superconductivity in Q-carbon.

  17. Effects of dietary boron on performance, egg production, egg quality ...

    African Journals Online (AJOL)

    engin

    Body weight was not affected by dietary boron supplementation at 16 and 40 weeks of age. ... and human nutrition. In bone metabolism, boron interacts with Ca, vitamin D and Mg (Chapin et al., 1998). In animals and plants, boron affects at least 26 enzymes involved in substrate metabolism, insulin release, oxidation and.

  18. Mesoscale Modeling of Dynamic Compression of Boron Carbide Polycrystals

    Science.gov (United States)

    2013-05-01

    occurs in ballistic impact, and accompanies amorphization in diamond anvil cell (DAC) experiments (Yan et al., 2009). Fracture in boron carbide ...Mesoscale Modeling of Dynamic Compression of Boron Carbide Polycrystals by J. D. Clayton ARL-RP-440 May 2013...Ground, MD 21005-5069 ARL-RP-440 May 2013 Mesoscale Modeling of Dynamic Compression of Boron Carbide Polycrystals J. D. Clayton

  19. Colorimetric Sugar Sensing Using Boronic Acid-Substituted Azobenzenes

    Directory of Open Access Journals (Sweden)

    Yuya Egawa

    2014-02-01

    Full Text Available In association with increasing diabetes prevalence, it is desirable to develop new glucose sensing systems with low cost, ease of use, high stability and good portability. Boronic acid is one of the potential candidates for a future alternative to enzyme-based glucose sensors. Boronic acid derivatives have been widely used for the sugar recognition motif, because boronic acids bind adjacent diols to form cyclic boronate esters. In order to develop colorimetric sugar sensors, boronic acid-conjugated azobenzenes have been synthesized. There are several types of boronic acid azobenzenes, and their characteristics tend to rely on the substitute position of the boronic acid moiety. For example, o-substitution of boronic acid to the azo group gives the advantage of a significant color change upon sugar addition. Nitrogen-15 Nuclear Magnetic Resonance (NMR studies clearly show a signaling mechanism based on the formation and cleavage of the B–N dative bond between boronic acid and azo moieties in the dye. Some boronic acid-substituted azobenzenes were attached to a polymer or utilized for supramolecular chemistry to produce glucose-selective binding, in which two boronic acid moieties cooperatively bind one glucose molecule. In addition, boronic acid-substituted azobenzenes have been applied not only for glucose monitoring, but also for the sensing of glycated hemoglobin and dopamine.

  20. Screening of Wheat Genotypes for Boron Efficiency in Bangladesh

    Science.gov (United States)

    A number of Bangladeshi wheat genotypes (varieties and advanced lines) have been tested for boron efficiency through sand culture experiments over two years (2007-08 & 2008-09) against two Thai check varieties ‘Fang 60’ (boron efficient) and ‘SW41’ (boron inefficient). Performances of the genotypes ...