A radionuclide generator for the production of211Pb and its daughters

²¹¹Pb and its daughters are produced in a generator system which utilizes the distillation of the intermediate daughter²¹⁹Rn from²²³Ra. The radium is precipitated as the stearate to isolate the parent while allowing the gaseous daughter to emanate. While the yield of the system is low, approximately 10%, the radionuclidic purity is extremely high. No measurable²²³Ra is found in the product.²²³Ra is separated from its parent,²²⁷Ac, by cation exchange.Deceased.Research supported in part by the Office of Health and Environmental Research, U.S. Dept. of Energy.     

Atomic SCF valence orbitals for first transition series metals

A consistent set of 4s, 4p, and 3d orbitals are reported that are linear combinations of Slatertype functions for the highest multiplicity term of the configurations 3d ⁿ–2 4s ¹4p ¹ for the metals titanium through copper.Research supported by the National Science Foundation, Grant No.NSF-GP-5498.NIH Predoctoral Fellow (1968–1970).Research Engineer; Dow Chemical Company, Freeport, Texas 77541.     

Theoretical studies of atmospheric molecules: SCF and correlated energy levels for the NO2, NO 2 + and NO 2 − systems

SCF and MC-SCF/CI calculations were carried out on the low-lying electronic states of NO₂, NO ₂ ⁺ and NO ₂ ^– , using a double-zeta quality basis set of contracted Gaussian functions. The calculations were performed primarily at the equilibrium geometry (R _NO = 2.25 a_o, _ONO=134 °) of theX ² A ₁ state of NO₂. SCF calculations on NO ₂ ⁺ in a linear conformation were also performed. Results are presented and compared with experiment and other calculations.Research supported in part by Air Force Delivery Orders F33615-72-M-5015 and MIPR889474-00117 and Air Force Office of Scientific Research and in part by the United States Energy Research and Development Administration.     

Variational calculations for helium-like ions using generalized Kinoshita-type expansions

 Variational calculations are reported for the ground states of the helium atom and its isoelectronic ions H⁻, Li⁺, …, Ne⁸⁺. The calculations use generalized Kinoshita expansions with freely optimized, noninteger powers of the Hylleraas coordinates s and u. One hundred-term expansions of this type lead to better energies than any other expansions in the literature with comparable numbers of terms. Received: 4 September 2002 / Accepted: 14 October 2002 / Published online: 21 January 2003 Correspondence to: T. Koga e-mail: koga@mmm.muroran−it.ac.jp Acknowledgements. This work was supported in part by the Natural Sciences and Engineering Research Council of Canada, and in part by a Grant-in-Aid for Scientific Research from the Ministry of Education of Japan. The final 100-term computations with real powers were performed at the Advanced Computational Research Laboratory of the University of New Brunswick.     

Neutron captue prompt gamma-ray activation analysis at the NIST Cold Neutron Research Facility

An instrument for neutron capture prompt gamma-ray activation analysis (PGAA) has been constructed as part of the Cold Neutron Research Facility at the 20 MW National Institute of Standards and Technology Research Reactor. The neutron fluence rate (thermal equivalent) is 1.5·10⁸ n ·cm^–2·s^–1, with negligible fast neutrons and gamma-rays. With compact geometry and hydrogen-free construction, the sensitivity is sevenfold better than an existing thermal instrument. Hydrogen background is thirtyfold lower.     

Rate of the reaction I2 + F2 → products

The rate coefficient, k1, for the reaction I2+F2k1→ products has been measured at room temperature to be k1 = (1.9 = 0.4) × 10?15 cm3/molecule s. The macroscopic rate is compared to microscopic cross-section data obtained from molecular beam experiments and is found to be consistent with the bimolecular reaction I2 + F2→ I2F + F.DG|National Research Council/Resident Research Associate.     

Bestimmung von Sulfid mit einer Sulfidionen-empfindlichen Elektrode

Zusammenfassung Mit der Sulfidionen-empfindlichen Elektrode der Fa. Orion Research Inc. können Na₂S-Konzentrationen bis herab zu 10^–3 M, nach Zugabe von Ascorbinsäure bis zu 10^–6 M gemessen werden. Der Einfluß des pH- Wertes und der Temperatur sowie die Wirkung von Zusätzen werden untersucht.

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Determination of sulphide by means of a sulphide-ion sensitive electrode

The sulphide-ion sensitive electrode (Orion Research Inc.) permits Na₂S-determinations down to concentrations of 10^–3 M, in presence of ascorbic acid to 10^–6 M. The influence of pH, temperature, and of added salts were tested.

     

Ab initio computation of the interaction energy curves for some low-lying states of CO which dissociate to ground-state3 P O and3 P C atoms

Summary We investigate the molecular electronic structure of the quintet states of CO which correspond to the C(³ P)+O(³ P) interaction at several levels of theory. We find the 1⁵⁺ state to be relatively deeply bound (D _e ca. 587 cm^–1) while the other quintets have relatively shallow potential wells (D _e<40 cm^–1) according to our multireference configuration interaction calculations which are counterpoise corrected for basis set superposition effects. Our results are in qualitative accord with the recent semiempirical estimates of Bussery and co-workers [(1989) Chem. Phys. 134:7].National Academy of Sciences, National Research Council, Air Force Astronautics Laboratory, Resident Research Associate 1987–89     

Plutonium, 137Cs and U in some pond and lake sediments from areas surrounding the Semipalatinsk Nuclear Test Site: With emphasis on anomalously high U accumulation

Sediment core samples were collected up to a depth of 25–40 cm from three ponds (P. Korosteli, P. Mihairov and P. Alkat) and two lakes (L. Kanoneruka and L. Semanaika) located in widely separated regions outside the former Semipalatinsk Nuclear Test Site (SNTS) in Kazakhstan. The ¹³⁷Cs, Pu and U concentrations with depth were determined in samples divided at 1 cm intervals from the top of each core. These sediment cores were dated by the excess ²¹⁰Pb method. The reservoirs with low sedimentation rates of 0.038–0.41 g·cm^–2·y^–1 permitted, but not in detail, the estimation of the depositional history of close-in fallout of ¹³⁷Cs and Pu within these regions. The sediments accumulating an anomalously high ²³⁸U concentration of 250–400 Bq/kg were also found for two of the five reservoirs, in which their ²³⁴U/²³⁸U and ²³⁵U/²³⁸U activity ratios were 1.3–2.0 and around 0.047 (nearly the same as that of natural U), respectively. Such U enrichment at the subsurface with a thin layer of lower-U sediment at the surface is mainly due to infiltration of lake water containing U from the ground water flowing into the lake or pond, followed by reduction of U(VI) to U(IV) at the redox boundary.The authors would like to express their gratitude to research staff of the Kazakh Scientific Research Institute for Radiation Medicine and Ecology for sediment and soil sampling. This work was supported by a Grant in Aid for Scientific Research from the Ministry of Education and Culture of Japan, Monbusuo International Scientific Research Program during the period of 1995–2003, represented by Profs. M. Hoshi and M. Yamamoto.     

Plutonium, 137Cs and U in some pond and lake sediments from areas surrounding the Semipalatinsk Nuclear Test Site: With emphasis on anomalously high U accumulation

Sediment core samples were collected up to a depth of 25–40 cm from three ponds (P. Korosteli, P. Mihairov and P. Alkat) and two lakes (L. Kanoneruka and L. Semanaika) located in widely separated regions outside the former Semipalatinsk Nuclear Test Site (SNTS) in Kazakhstan. The ¹³⁷Cs, Pu and U concentrations with depth were determined in samples divided at 1 cm intervals from the top of each core. These sediment cores were dated by the excess ²¹⁰Pb method. The reservoirs with low sedimentation rates of 0.038–0.41 g·cm^–2·y^–1 permitted, but not in detail, the estimation of the depositional history of close-in fallout of ¹³⁷Cs and Pu within these regions. The sediments accumulating an anomalously high ²³⁸U concentration of 250–400 Bq/kg were also found for two of the five reservoirs, in which their ²³⁴U/²³⁸U and ²³⁵U/²³⁸U activity ratios were 1.3–2.0 and around 0.047 (nearly the same as that of natural U), respectively. Such U enrichment at the subsurface with a thin layer of lower-U sediment at the surface is mainly due to infiltration of lake water containing U from the ground water flowing into the lake or pond, followed by reduction of U(VI) to U(IV) at the redox boundary.The authors would like to express their gratitude to research staff of the Kazakh Scientific Research Institute for Radiation Medicine and Ecology for sediment and soil sampling. This work was supported by a Grant in Aid for Scientific Research from the Ministry of Education and Culture of Japan, Monbusuo International Scientific Research Program during the period of 1995–2003, represented by Profs. M. Hoshi and M. Yamamoto.     

Anomalous90Sr deposition during the fall, 1995 at MRI, Tsukuba, Japan

We have observed an anomalous⁹⁰Sr deposition at the Meteorological Research Institute (MRI), Tsukuba, Japan during the fall of 1995. This anomalous⁹⁰Sr deposition was confirmed by the re-analysis of the sample, the associated lowest¹³⁷Cs/⁹⁰Sr activity ratio and high r/s ratio, etc. We discuss the cause of this anomalous⁹⁰Sr deposition and conclude that the anomalous⁹⁰Sr may come from an accidental release of nuclear battery, etc.     

Determination of boron in magnesium oxide by charged particle activation analysis

The determination of boron in magnesium oxide using the¹⁰B/p, /⁷Be,¹⁰B/d, n/⁷Be, and¹⁰B/d, n/¹¹C reactions is described. Lithium interferes the nuclear reactions leading to beryllium-7. Combination of a proton and deuteron irradiation, each followed by measurement of the induced beryllium-7 activity, allows a simultaneous determination of boron and lithium. The¹⁰B/d, n/¹¹C reaction is free from nuclear interferences. The boron concentration ranges from 1.5 to 850 g g^–1. The results obtained by the two methods are in good agreement.Senior Research Associate of the Belgian National Fund for Scientific Research.     

A new fluorescent sensor selective for Pb<Superscript>2+</Superscript> in water capable of two-photon-induced fluorescence measurement

A new fluorescent sensor (1) for Pb²⁺ containing a 1,4-dicyano-2,5-bis(styryl)benzene fluorophore and 2-(N,N′-bis(carboxylmethyl))amino-1-carboxylmethoxylbenzene as receptor has been synthesized. The sensor selectively responds to Pb²⁺ in the aqueous environment, and brings about similar and significant changes in one- and two-photon excited emission spectra: λ _max red-shift from 460 (519) to 590 nm. The selective response is pH-independent in a large physiological pH range, and two-photon action cross section (ϕδ) is 51 GM (1 GM = 1×10⁻⁵⁰ cm⁴·s·photon⁻¹·molecule⁻¹) at 740 nm. Supported by the National Natural Science Foundation of China (Grant Nos. 20705621 & 20706008), the National Basic Research Project of China (Grant No. 2009CB724706), the Ministry of Education of China, Changjiang Scholars Innovative Research Team in University (Grant No. IRT0711) and Cultivation Fund of the Key Scientific and Technical Innovation Project (Grant No. 707016)     

The191Os/191mIr generator for clinical use

An evaluation of adsorbents for potential use in the¹⁹¹Os/^191mIr medical radionuclide generator was performed. The adsorbents included 39 inorganic materials broadly classified as oxides, antimonates, ferro-ferricyanides, phosphates, sulfides, and miscellaneous including activated carbon and the organic anion-exchanger AGMP-1. The uptake of¹⁹¹Os in oxidation states (VI) [potassium tetrachloroosmate], (IV) [potassium hexachloroosmate] and (III) [potassium hexathiocyanatoosmate] was measured. Adsorbents having a high¹⁹¹Os uptake were evaluated for^191mIr elution yield using three physiologically compatible eluents. Only activated carbon and AGMP-1 adsorbents showed significant^191mIr elution yields under the test conditions (10% and 37%, respectively). The results of these studies suggest that activated carbon may be a promising adsorbent for development of a new¹⁹¹Os/^191mIr medical radionuclide generator. Activated carbon is a good candidate for further development since it is inert to the chemical and radiation effects which may effect an organic based ion exchange material such as AGMP-1.Research sponsored by the Office of Health and Environmental Research, U.S. Department of Energy under contract DE-AC05-840R21400 with Martin Marietta Energy Systems, Inc.     

A new method for generating organosilanones

A new method for the generation of organosilanones by the reaction of betaines, R₃P⁺-CR¹R²-SiR³R⁴-S^–, with (Et₃Sn)₂O was suggested.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2246–2247, December, 1994.This study was financially supported by the Russian Foundation for Basic Research, Project No. 94-03-09710.     

Frequency dependence of nuclear magnetic resonance parameters in poly(methyl methacrylate)

Using 26 NMR spectrometers, the Research Group on NMR, the Society of Polymer Science, Japan observed the ¹H NMR chemical shift, resolution, and signal intensity; ¹³C NMR chemical shift, resolution, and signal intensity; the effect from initiator fragment signal; ¹H spin-lattice relaxation times; ¹³C spin-lattice relaxation times; and ¹³C nuclear Overhauser enhancement of radically polymerized poly(methyl methacrylate). Excellent reliability was found after comparison between the data from different spectrometers. Molecular motion of this polymer was analyzed with a term of 3τ model.     

Radiopharmaceutical complexes of technetium and tin: Physicochemical and biochemical research

The list of the developed^99mTc-kits in our research center is given, while the whole research work as a basis of^99mTc scanning agents production is described. Research involved physico-chemical studies of both types of complexes: tin and technetium-99 complexes as model compounds for^99mTc-radiopharmaccuticals, as well as biochemical studies including interaction with blood proteins, as well as subcellular localization of certain^99mTc,⁹⁹Tc-complexes.     

Carbon-14 labelling of biomolecules induced by14CO ionized gas

Ionized¹⁴CO gas provides a rapid method for producing¹⁴C-labelled biomolecules. The apparatus consists of a high vacuum system in which a small amount of¹⁴CO is ionized by electron impact. The resulting species drift towards a target where they interact with the molecule of interest to produce¹⁴C-labelled compounds. Since the reaction time is only 2 minutes, the method is particularly promising for producing tracer biomolecules with short-lived¹¹C at high specific activities. We have studied the applicability of the method to various classes of compounds of biological importance, including sterids, alkaloids, prostaglandins, nucleosides, amino acids and proteins. All compounds treated gave rise to¹⁴C addition and degradation products. Furthermore, for some compounds, chromatographic analysis in multiple systems followed by derivatization and crystallization to constant specific activity, indicated that carbon exchange may occur to produce the labelled, but otherwise unaltered substrate in yields of the order of 10–100 mCi/mol. More conclusive proof of radiochemical identity must await production of larger quantities of material and rigorous purification including at least two different chromatographic techniques. Supported by the Medical Research Council of Canada Grant MA-6137, and by the Banting Research Foundation.     

Eine 3mg-252Cf-Bestrahlungsanordnung-Aufbau und Anwendungen

In the last years Cf-252 neutron sources will be incresingly used for nuclear analytical purposes. In the Central Institute of Isotope and Radiation Research, Leipzig, an irradiation equipment with a 3mg²⁵²Cf neutron source was constructed. It reaches thermal neutron fluxes of about 10⁷ n·cm^–2·s^–1. The construction of this equipment and the different moderation geometries are described. Possibilities of the application for neutron induced autoradiography, neutron radiography and neutron activation analysis are demonstrated on examples.     

Medical isotope development and supply opportunities in the 21st century

Research in extending medical isotopes for the diagnosis and treatment of numerous health maladies is hampered by outages and upsets in major supply sources. Investigations in cures for brain cancer (²¹¹At), HIV/AIDS virus (²¹³Bi), and even bacterial vectors are either in reduced progress mode or have been cancelled until isotopes become available. Examples of several key radioactive medical isotopes include ^99mTc for diagnostics, ¹³¹I for non-Hodgkin’s lymphoma and thyroid cancer, ²²⁵Ac for acute myelogenous leukemia, and ⁶⁷Cu for lymphoma cancer. Possibilities for developing commercially viable sources using compact accelerators and next generation research and production reactors are discussed.