Alternative chromatographic processes for no-carrier added 177Lu radioisotope separation

HPLC technique combined with the simple conventional column solid phase extraction (SPE) chromatography using di-(2-ethylhexyl)orthophosphoric acid (HDEHP) impregnated OASIS-HLB sorbent based SPE resins (OASIS-HDEHP) was developed for the separation of no-carrier added (n.c.a) ¹⁷⁷Lu from the bulk quantity of ytterbium target. This combination strategy was based on combining the advantages of the better resolution of HPLC separation of n.c.a ¹⁷⁷Lu from the few milligram level Yb target with the high capacity of the OASISHDEHP column for the separation of ¹⁷⁷Lu from the bulk Yb target. The production batches of several hundred mCi activity of n.c.a ¹⁷⁷Lu radioisotope separated from 50 mg Yb target activated in a nuclear reactor of medium neutron flux (Φ=5·10¹³ n·cm^?2·s^?1) were successfully performed using this combined separation technique. With the target irradiation in a reactor of higher thermal neutron flux or with the parallel run of several separation units, several Ci-s of n.c.a ¹⁷⁷Lu can be profitably produced on a commercial production basis.     

Award for service Professor Jean-Marie Lehn

Chronicle

Award for service Professor Jean-Marie Lehn     

The beauties of calorimetry An overview

This paper gives a short overview of direct and indirect calorimetric experiments to determine the heat production or at least the metabolic turnover of whole plants or their blossoms. A special emphasis is placed on thermogenic plants because of their high specific heat production rates equal to those of mammals or birds and sometimes even surpassing them.     

Approaches to Carbocyclic Sialidase Inhibitors Invited Review

 The crucial role played by carbohydrates in many physiological processes has made this class of compounds an interesting target for drug design. Consequently mimicking carbohydrates has been one of the most rapidly growing fields in synthetic organic chemistry in recent years, and particularly intense focus has been devoted to sialic acids and sialic acid metabolizing enzymes, including sialidases. Inhibition of the latter enzyme from influenza virus can be regarded as one of the most successful examples of structure-based drug design and high affinity inhibitors based on neuraminic acid have been developed. There is an ongoing search for inhibitors with improved physicochemical properties and among them, carbocyclic systems, where the ring oxygen of the carbohydrate is replaced by carbon, have become the center of interest. This review intends to give a brief overview over the structures and synthetic approaches which surfaced in the last decade.     

Interactions of ammonium nitrate with different additives Thermodynamic analysis

In order to elucidate the influence of Ca and Mg carbonates with or without the presence of boron, manganese and copper compounds on the thermal stability of ammonium nitrate (AN), thermodynamic analysis of different reactions between AN and additives was carried out. Temperature dependency of Gibbs free energy changes ∆G _T and equilibrium composition of reaction products were calculated for a set of reactions using the HSC software. Main solid compounds that can form in the systems of AN and carbonates, were Ca(NO₃)₂ and Mg(NO₃)₂, Ca(OH)₂ and Mg(OH)₂, CaO₂ and MgO₂, CaO and MgO, and N-containing gaseous compounds NO, N₂O and NO₂. As a result of H₃BO₃, MnO₂ and CuSO₄ addition, the content of CuO, Cu₂O and MnO as solids and SO₂, SO₃ and HBO as gaseous reaction products reached the same level. Thereby, their equilibrium concentrations did not depend on the carbonate origin of CaCO₃, MgCO₃ or CaMg(CO₃)₂. Small amount of CuSO₄, H₃BO₃ or MnO₂ additive (0.01–0.05 mol) in the system, practically, did not influence the temperature dependencies of ∆G _T of the reactions between AN and CaCO₃ or CaMg(CO₃)₂. The influence of additives taken in the larger amount (0.5 mol) was evident and, depending on the additive and reaction, shifted their proceeding temperatures in either direction by more than 300–400 K.     

Thermodynamic properties of binary mixtures containing oxaalkanes Part VI. Monoethers, acetals, diethers, cyclic mono- and di-ethers?+?tetrachloromethane

The data available in the literature on thermodynamic properties concerning different oxaalkanes + tetrachloromethane mixtures are examined on the basis of the DISQUAC group contribution model. The obtained interaction parameters, dispersive and quasichemical, depend on the intramolecular environment of the O atom. The steric effect results in a regular decrease of the quasichemical interaction parameters of the oxygen/tetrachloromethane (e,d)-contact in linear ethers. The proximity effect of the O atoms generates lower coefficients in dioxaalkanes with respect to monooxaalkanes and because of the ring strain, being the quasichemical coefficients constant, the dispersive parameters in cyclic molecule are higher than in linear ethers.     

Dissolution kinetic and structural behaviour of natural hydroxyapatite vs. thermal treatment Comparison to synthetic hydroxyapatite

The dissolution kinetic and structural behaviour of natural hydroxyapatite (N-HA) and synthetic hydroxyapatite (S-HA) was studied vs. sintering temperature and using ‘in vitro’ experiments. Obtained results highlight the chemical stability of N-HA. Any structural modification was observed until 1200°C. In the fact S-HA undergoes some modifications. XRD diagrams show the tricalcium phosphate (TCP) phase formation between 800 and 1100°C and tetracalcium phosphate (TetCP) phase formation at 1200°C. The ‘in vitro’ assay shows that the dissolution was occurred more in N-HA than in S-HA. The formed TCP activated the dissolution kinetic and then the precipitation phenomena when a continuous dissolution of TetCP leaded to slow down the kinetic precipitation.     

cis Δ5-octahydro-1-naphtalenones and cis Δ5-decahydro-1-naphthalenes (cis-1-decalones) by stereoselective intramolecular diels-alder reaction.

Intramolecular DIELS-ALDER reactions of requisite trienes led to $\text{cis}$-1-decalones, $\text{via}$ an endo intermediate state.