Status of heavy element research using a gas-filled recoil separator at RIKEN

A gas-filled type of recoil separator for heavy element research was installed at an experimental hall of RIKEN Linear Accelerator facility to realize getting higher intensity of primary beam and long beam time. Performance of the separator was studied using target recoils and various nuclear reactions. The results show the high performance of the separator for heave element research. As an application of the GARIS, production and identification of an isotope of the 110th element ²⁷¹[110] have been performed using the ²⁰⁸Pb(⁶⁴Ni,1n)²⁷¹[110] reaction. Three decay chains coincide well both in decay times and energies with the ones reported by the group of SHIP experiment at GSI, Germany. Our results provide a confirmation of the synthesis of an isotope ²⁷¹[110] of element 110.     

Measurement on Spot Size Dependence of Dense WDM Dielectric Multilayer Filters

We present the spot size dependence of dielectric multilayer filters for use in dense WDM systems. We found large dependences of filter performances on the spot size and the incident angle of input light, which should be important for miniaturizing multi-channel add/drop filters.     

Preparation and evaluation of oral dosage form using acylglycerols. II. Effect of food ingestion on dissolution and absorption of aspirin from the granules prepared by acylglycerols in human subjects.

The dissolution behavior of the aspirin enteric granule prepared using acylglycerols, glyceryl monostearate (GMS) and glyceryl trilaurate (GTL), was investigated in vitro and in human subjects in a fasting or non-fasting state. Aspirin was slowly released from the granule in vitro at pH 1.2. No acceleration of the aspirin dissolution rate in the medium without lipase and cholic acid was observed when the pH level of the medium increased to a neutral region (pH 6.4). However, the dissolution of aspirin was significantly increased by increasing the concentrations of lipase and cholic acid in the medium. Lipase appears to play an essential role in the dissolution process of aspirin granules. In human subjects, the average levels of the cumulative amount of total salicylate excreted in a urine-time curve, and the mean residence time (MRT) obtained after oral administration of a granule in the fasting state were markedly delayed in comparison with the results observed using an aqueous solution and a crystalline form of aspirin. In comparing the fasting condition with the non-fasting condition (after food ingestion), no significant difference was recognized in the total amount of salicylate excreted in urine to an infinite time (Ae(infinity)), whether the MRT was obtained by granule, crystalline form or aqueous solution. It can be concluded that aspirin granule prepared by GMS and GTL has a property of pancreatic lipase-sensitive dissolution, and its bioavailability is unaffected by food intake.     

Tensor analyzing power T 20 of the dd → 3Hen and dd → 3Hp reactions at zero angle for energies 140, 200, and 270 MeV

RIKEN Accelerator Research Facility data on the tensor analyzing power T ₂₀ of the dd → ³Hen and dd → ³Hp reactions at zero angle for deuteron kinetic energies of 140, 200, and 270 MeV are reported. The observed positive sign of T ₂₀ clearly demonstrates the sensitivity to the D/S-wave ratio in the ³He and ³H wave functions in the energy range of the experiment. Data on T ₂₀ for the ³Hen channel are in agreement with those for the ³Hp channel within the experimental errors.     

Electrochemical oxidation of ethyl 3-oxo-3-phenyl-2-phenylhydrazonopropionate

The electrochemical oxidation of ethyl 3-oxo-3-phenyl-2-phenylhydrazonopropionate has been studied in the pH range 3.0–11.0 at a pyrolytic graphite electrode by linear and cyclic sweep voltammetry, coulometry and spectral studies. The results indicate that the 2 e⁻, 2 H⁺ oxidation of this compound gives phenol and ethyl 3-phenyl-2,3-dioxopropionate as the major products of electrooxidation.     

Stereoselective synthesis of (25R)-25,26-dihydroxy-23-oxovitamin D3 and its enzymatic conversion to (25R)-1α,25,26-trihydroxy-23-oxovitamin D3, a putative metabolite of vitamin D3

(25$\text{R}$)-25,26-Dihydroxy-23-oxovitamin D₃ was synthesized efficiently and stereoselectively, and it was converted enzymatically to (25$\text{R}$)-1α,25,26-trihydroxy-23-oxovitamin D₃, a putative metabolite of 1α,25-dihydroxyvitamin D₃. The spectral and chemical properties of (25$\text{R}$)-25,26-dihydroxy-23-oxovitamin D₃ and its 1α,hydroxylated derivative disagree with those reported for the isolated metabolite.     

Isoperthiocyanic acid (3-amino-5-thione-l, 2, 4-dithiazole) as a new reagent for the selective detection of nitrite ion

Summary A new, simple, and selective test is described for the detection of nitrite ion with isoperthiocyanic acid (I) as the reagent. The test is based on the reaction of a 5% solution ofI with the nitrite ion solution, a deep orange precipitate being formed. Conversely, the test can be used in the identification ofI itself. Presumably, the coloured product is 3-hydroxy-5-thione-1, 2, 4-dithiazole, formed by the action of nitrous acid (producedin situ by the action of sulphuric acid and nitrite) on the 3-amino group ofI. The limit of detection is 300g of NO₂ ^– in a drop (0.05 ml). Most anions (including IO₃ ^–) do not interfere. Only I^–, thiourea, and hydrogen peroxide interfere; S₂O₃ ^2– interferes only when present in large amounts.

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Zusammenfassung Ein neuer, einfacher und selektiver Nachweis von Nitrit mit Isoperthio cyansäure (I) wurde beschrieben. Er beruht auf der Umsetzung einer 5% igen Lösung von I mit Nitritlösung, wobei ein tief orange gefärbter Niederschlag entsteht. Umgekehrt kann die Reaktion auch zum Nachweis von I dienen. Vermutlich handelt es sich bei dem gefarbten Produkt um 3-Hydroxy-5-thion-1, 2, 4-dithiazol, das durch Einwirkung der salpetrigen Säure auf die 3-Aminogruppe von I entsteht. Die Erfassungsgrenze betragt 300g NO₂ ^–im Tropfen (0,05 ml). Die meisten Anionen (inklusive JO₃ ^–) stören nicht. Nur J^–, Thioharnstoff und H₂O₂ stören; Thiosulfat stört nur in großen Mengen.

     

Alkyl–oxygen bond formation in the mass spectra of α-chloromethyl aryl sulphones

When subjected to electron-impact, chloromethyl aryl sulphones (II, X = Cl) fragment predominantly by the loss of CH₂Cl from the molecular ion followed by the loss of SO₂ and in most cases the appropriate metastable peaks are present to confirm the transitions. In addition, alkyl–oxygen bond formation in the molecular ion was revealed by the presence of prominent peaks corresponding to the [R? ?-SO]⁺ ions. In most spectra no evidence for aryl–oxygen bond formation could be found and thus the presence of the chlorine atom was able to effectively reverse the direction of skeletal rearrangement reported for aryl methyl sulphones.     

Recoil128I atoms in iodine pentoxide under /n, γ/ process

An attempt js made to study the behaviour of recoil¹²⁸I atoms in neutron irradiated I₂O₅ at ambient temperature. The initial retention is found to be 44±2%. However, a substantial increase /57±2%/ in the value is observed upon heating the sample at 473 K for 1 h prior to irradiation. A kinetic study of post-recoil thermal annealing of neutron irradiated material is also presented. Effect of pre-heat treatment results in a decrease of rate constants and saturation retention values at respective temperatures while the E_act for the overall process remains almost unaltered.