Magicity versus Superfluidity around

The neutron-rich unbound fluorine isotope ^{30}F_{21} has been observed for the first time by measuring its neutron decay at the SAMURAI spectrometer (RIBF, RIKEN) in the quasifree proton knockout reaction of ^{31}Ne nuclei at 235 MeV/nucleon. The mass and thus one-neutron-separation energy of ^{30}F has been determined to be S_{n}=-472±58(stat)±33(sys) keV from the measurement of its invariant-mass spectrum. The absence of a sharp drop in S_{n}(^{30}F) shows that the "magic" N=20 shell gap is not restored close to ^{28}O, which is in agreement with our shell-model calculations that predict a near degeneracy between the neutron d and fp orbitals, with the 1p_{3/2} and 1p_{1/2} orbitals becoming more bound than the 0f_{7/2} one. This degeneracy and reordering of orbitals has two potential consequences: ^{28}O behaves like a strongly superfluid nucleus with neutron pairs scattering across shells, and both ^{29,31}F appear to be good two-neutron halo-nucleus candidates.

First observation of 28O.

Subjecting a physical system to extreme conditions is one of the means often used to obtain a better understanding and deeper insight into its organization and structure. In the case of the atomic nucleus, one such approach is to investigate isotopes that have very different neutron-to-proton (N/Z) ratios than in stable nuclei. Light, neutron-rich isotopes exhibit the most asymmetric N/Z ratios and those lying beyond the limits of binding, which undergo spontaneous neutron emission and exist only as very short-lived resonances (about 10-21 s), provide the most stringent tests of modern nuclear-structure theories. Here we report on the first observation of 28O and 27O through their decay into 24O and four and three neutrons, respectively. The 28O nucleus is of particular interest as, with the Z = 8 and N = 20 magic numbers1,2, it is expected in the standard shell-model picture of nuclear structure to be one of a relatively small number of so-called 'doubly magic' nuclei. Both 27O and 28O were found to exist as narrow, low-lying resonances and their decay energies are compared here to the results of sophisticated theoretical modelling, including a large-scale shell-model calculation and a newly developed statistical approach. In both cases, the underlying nuclear interactions were derived from effective field theories of quantum chromodynamics. Finally, it is shown that the cross-section for the production of 28O from a 29F beam is consistent with it not exhibiting a closed N = 20 shell structure.

First Application of Mass Measurements with the Rare-RI Ring Reveals the Solar r-Process Abundance Trend at A=122 and A=123.

The Rare-RI Ring (R3) is a recently commissioned cyclotronlike storage ring mass spectrometer dedicated to mass measurements of exotic nuclei far from stability at Radioactive Isotope Beam Factory (RIBF) in RIKEN. The first application of mass measurement using the R3 mass spectrometer at RIBF is reported. Rare isotopes produced at RIBF-^{127}Sn, ^{126}In, ^{125}Cd, ^{124}Ag, ^{123}Pd-were injected in R3. Masses of ^{126}In, ^{125}Cd, and ^{123}Pd were measured whereby the mass uncertainty of ^{123}Pd was improved. This is the first reported measurement with a new storage ring mass spectrometry technique realized at a heavy-ion cyclotron and employing individual injection of the preidentified rare nuclei. The latter is essential for the future mass measurements of the rarest isotopes produced at RIBF. The impact of the new ^{123}Pd result on the solar r-process abundances in a neutron star merger event is investigated by performing reaction network calculations of 20 trajectories with varying electron fraction Y_{e}. It is found that the neutron capture cross section on ^{123}Pd increases by a factor of 2.2 and ß-delayed neutron emission probability, P_{1 n}, of ^{123}Rh increases by 14%. The neutron capture cross section on ^{122}Pd decreases by a factor of 2.6 leading to pileup of material at A=122, thus reproducing the trend of the solar r-process abundances. The trend of the two-neutron separation energies (S_{2n}) was investigated for the Pd isotopic chain. The new mass measurement with improved uncertainty excludes large changes of the S_{2n} value at N=77. Such large increase of the S_{2n} values before N=82 was proposed as an alternative to the quenching of the N=82 shell gap to reproduce r-process abundances in the mass region of A=112-124.

Diffuse large B cell lymphoma expressing the natural killer cell marker CD56.

The expression of the natural killer (NK) cell antigen, CD56, in hematological malignancies is rare. However, there are several reports that some hematological malignancies, such as T/NK cell lymphoma, multiple myeloma (MM) and acute myeloid leukemia (AML), express this molecule. In B cell non-Hodgkin's lymphomas (NHL), however, very limited number of cases have been reported to express CD56 molecule. Although one study has recently described that half of microvillous B cell lymphoma (MVL), an uncommon subset of large cell lymphoma, expressed CD56, there have been no reports about most common type of B-NHL, diffuse large B cell lymphoma (DLBL) other than a mention of weak CD56 expression in one of 83 DLBL. We herein presented the first case of diffuse large B cell lymphoma expressing CD56 clearly. The immunophenotype determined by immunostaining and flow cytometric analysis was CD10+, CD19+, CD20+, CD45RO-, CD3- and CD56+. On immunohistochemical study, neither bcl-2 nor TIA-1 was positive for tumor cell. Monoclonal immunoglobulin heavy chain (IgH) gene rearrangement was detected, and the sequence analysis of the variable region of IgH (VH) suggested that this tumor was derived from antigen selected post germinal center B cell. Conventional combination chemotherapy (CHOP) was administered, and the patient has still been in complete remission for 10 months.

[SLE with interstitial pneumonia during cyclophosphamide pulse therapy].

A 49 year-old man was admitted for edema and renal impairment due to SLE. Since he did not improve with predonisolone and methylprednisolone pulse therapy, cyclophosphamide pulse therapy (300 mg div.) was administered. The patient subsequently developed a fever, dyspnea and cough, and interstitial regions of the lungs exhibited shadows on X-ray and CT. The patient also suffered hypoxemia and poor lung function. Since several culture tests and viral antibody tests were negative for infection, antibiotics were not effective, and TBLB indicated interstitial pneumonia, which we speculated was induced by cyclophosphamide. However, this was such a severe case of interstitial pneumonia that it could not be cured merely by discontinuing the cyclophosphamide, but it did improve immediately after starting methylprednisolone pulse therapy. The incidence of cyclophosphamide-induced interstitial pneumonia is very low, but the mortality rate is high. Since cyclophosphamide pulse therapy is often used to treat SLE, attention should be focused on the incidence of interstitial pneumonia.

Isolation from Streptomyces of a novel naphthoquinone compound, naphthablin, that inhibits Abl oncogene functions.

In the course of our screening for inhibitors of abl oncogene function, a culture filtrate of Streptomyces aculeolatus, induced normal flat morphology in v-abl-expressing NIH3T3 cells. The active substance was isolated through ethyl acetate extraction, silica gel column chromatography, and reverse-phase HPLC. Mass and NMR spectroscopy including HMBC revealed that it had a novel naphthoquinone structure with a monoterpene, and we named it "naphthablin". Naphthablin inhibited Abl-induced morphological transformation in v-ablts-NIH3T3 cells at around 30 micrograms/ml, and specifically inhibited RNA synthesis.

Taste discrimination using alternative solvents for PTC and NaCl.

Better discrimination was possible between threshold PTC solutions and pure solvent when the solvent was a tasteless, low concentration NaCl solution to which the subject had adapted, than when the solvent was purified water. The reverse was true for threshold NaCl stimuli. Subjective reports indicated this to be due to the absence or presence of taste cues from the solvent and stimulus after-effects. Interstimulus rinsing with the appropriate solvent improved discrimination.

Induction of erythroid differentiation in leukaemic K562 cells by an S-adenosylhomocysteine hydrolase inhibitor, aristeromycin.

We have isolated an unusual nucleoside, aristeromycin, from the culture filtrate of Actinomycetes as a compound that induces normal morphology in v-ablts-NIH3T3 cells. Aristeromycin also induced erythroid differentiation in abl-expressing human chronic myelogenous leukaemia K562 cells. It did not affect the amount of Abl or the Abl-associated tyrosine kinase activity in either v-ablts-NIH3T3 or K562 cells. As a potent inhibitor of S-adenosylhomocysteine hydrolase, aristeromycin inhibited methylation of phosphatidylethanolamine to form phosphatidylcholine in K562 cells. Among aristeromycin analogues, the activity to inhibit S-adenosylhomocysteine hydrolase was paralleled with the induction of erythroid differentiation. Thus, aristeromycin inhibits abl functions indirectly, possibly by inhibiting biological methylations.

[Fulminant hepatic failure induced by intermediate dose methotrexate in a case of non-Hodgkin's lymphoma].

Methotrexate (MTX) is frequently used as an antifolics agent in many malignant neoplasms such as leukemia, lymphoma and osteosarcoma. The major side effects of MTX are liver and renal damages, bone marrow suppression and so on. But careful management and citrovorum factor rescue could decrease the incidence and degree of these side effects. In this report, we described a patient with non-Hodgkin's lymphoma who developed and died of fulminant hepatic failure soon after the administration of intermediate dose MTX. Serological tests for HB virus were not changed throughout, and lymphocyte stimulation test for MTX was strongly positive. His autopsy revealed no inflammatory cell infiltration into the liver, but marked biliary congestion which is a distinctive feature of drug induced hepatitis. From above results, it was suggested that nature of this fulminant hepatic failure was an allergic reaction to MTX. There is no previous report which is concerning about MTX and fetal drug related hepatic failure.

Kidney function in the severely jaundiced dog.

An attempt was made to prepare experimental models of jaundice in order to study the relation between jaundice and kidney function. Choledochal ligation and surgical division as a conventional means of achieving this aim proved useless in satisfying our requirements. The use of the choledochocaval shunt technique that we devised resulted in successful preparation of models of severe jaundice with a resultant total bilirubin value of 19.2 +/- 8.0 mg/dl at 1 week and 23.9 +/- 8.7 mg/dl 3 weeks postoperatively. Through these models the relation between jaundice and kidney function and the resultant histopathologic features of the kidneys were studied. In the animal models a significantly lower value was obtained for both glomerular filtration rate and renal plasma flow at 1 and 3 weeks postoperatively than in the other groups (undergoing choledochal ligation with division and unilateral nephrectomy, respectively). Histopathologic examination of the kidneys of these animals revealed no marked changes in the glomeruli or Bowman's capsule. Characteristic histopathologic features of the kidneys included swelling and exfoliation of epithelial cells because of reabsorption of bile in the proximal tubules and disintegration of the cell membrane.

Complications associated with the use of the Fogarty balloon catheter.

Over the past eight years at the OMCH Fogarty balloon catheter have been used for one hundred instances of acute arterial occlusion and for twenty instances of venous thrombosis. Compication developed on seven occasions, three in the operation for arterial thrombosis and four during venous thrombectomy. Three types of complications in the arterial system were encountered: removal of intima with thrombi, arterial rupture and thrombotic occlusion due to dissection of intima. All of these complications were successfully treated with appropriate procedures. Two types of complications in the venous system were encountered: perforation of iliac vein by the tip of the catheter (3 cases) and loss of the balloon intravenously (1 case). In the former complicated group, the first case died of hemorrhagic shock, the second case recovered uneventfully without any procedures and the last case was successfully trated by operative hemostatic procedure. In the case of latter complication, it was not possible to remove the lost balloon in the left posterior tibial vein in spite of strenuous efforts to retrieve it. Detailed discussion for prevention or treatment of these complications was done chiefly based on our experience.