Proton Shell Gaps in N=28 Nuclei from the First Complete Spectroscopy Study with FRIB Decay Station Initiator.

The first complete measurement of the ß-decay strength distribution of _{17}^{45}Cl_{28} was performed at the Facility for Rare Isotope Beams (FRIB) with the FRIB Decay Station Initiator during the second FRIB experiment. The measurement involved the detection of neutrons and γ rays in two focal planes of the FRIB Decay Station Initiator in a single experiment for the first time. This enabled an analytical consistency in extracting the ß-decay strength distribution over the large range of excitation energies, including neutron unbound states. We observe a rapid increase in the ß-decay strength distribution above the neutron separation energy in _{18}^{45}Ar_{27}. This was interpreted to be caused by the transitioning of neutrons into protons excited across the Z=20 shell gap. The SDPF-MU interaction with reduced shell gap best reproduced the data. The measurement demonstrates a new approach that is sensitive to the proton shell gap in neutron rich nuclei according to SDPF-MU calculations.

Microsecond Isomer at the N=20 Island of Shape Inversion Observed at FRIB.

Excited-state spectroscopy from the first experiment at the Facility for Rare Isotope Beams (FRIB) is reported. A 24(2)-µs isomer was observed with the FRIB Decay Station initiator (FDSi) through a cascade of 224- and 401-keV γ rays in coincidence with ^{32}Na nuclei. This is the only known microsecond isomer (1 µs≤T_{1/2}<1 ms) in the region. This nucleus is at the heart of the N=20 island of shape inversion and is at the crossroads of the spherical shell-model, deformed shell-model, and ab initio theories. It can be represented as the coupling of a proton hole and neutron particle to ^{32}Mg, ^{32}Mg+π^{-1}+ν^{+1}. This odd-odd coupling and isomer formation provides a sensitive measure of the underlying shape degrees of freedom of ^{32}Mg, where the onset of spherical-to-deformed shape inversion begins with a low-lying deformed 2^{+} state at 885 keV and a low-lying shape-coexisting 0_{2}^{+} state at 1058 keV. We suggest two possible explanations for the 625-keV isomer in ^{32}Na: a 6^{-} spherical shape isomer that decays by E2 or a 0^{+} deformed spin isomer that decays by M2. The present results and calculations are most consistent with the latter, indicating that the low-lying states are dominated by deformation.

Crossing N=28 Toward the Neutron Drip Line: First Measurement of Half-Lives at FRIB.

New half-lives for exotic isotopes approaching the neutron drip-line in the vicinity of N∼28 for Z=12-15 were measured at the Facility for Rare Isotope Beams (FRIB) with the FRIB decay station initiator. The first experimental results are compared to the latest quasiparticle random phase approximation and shell-model calculations. Overall, the measured half-lives are consistent with the available theoretical descriptions and suggest a well-developed region of deformation below ^{48}Ca in the N=28 isotones. The erosion of the Z=14 subshell closure in Si is experimentally confirmed at N=28, and a reduction in the ^{38}Mg half-life is observed as compared with its isotopic neighbors, which does not seem to be predicted well based on the decay energy and deformation trends. This highlights the need for both additional data in this very exotic region, and for more advanced theoretical efforts.

SAFIIRA: A heavy-ion multi-purpose irradiation facility in Brazil.

This work describes the new facility for applied nuclear physics at the University of Sao Paulo, mainly for irradiation of electronic devices. It is a setup composed of a quadrupole doublet for beam focusing/defocusing plus multiple scattering through gold foils to produce low intensity, large-area, and high-uniformity heavy-ion beams from 1H to 107Ag. Beam intensities can be easily adjusted from 102 particles cm2/s to hundreds of nA for an area as large as 2.0 cm2 and uniformity better than 90%. Its irradiation chamber has a high-precision motorized stage, and the system is controlled by a LabViewTM environment, allowing measurement automation. Design considerations and examples of use are presented.

Chronic inhaled cocaine abuse may predispose to the development of pancreatic adenocarcinoma.

BACKGROUND: The acute and chronic effects of cocaine over various organ systems have been well documented. A more recent approach to the effects of this drug has focused on the immunological consequences of its exposure, with results that indicate a possible carcinogenic effect. METHODS: A chart review was made in order to search for young pancreatic adenocarcinoma patients (arbitrarily defined as younger than 40) who made use of inhaled cocaine. This age was chosen because of a higher probability of cocaine addiction than at older ages. RESULTS: Of the 198 patients with pancreatic adenocarcinoma, 13 were younger than 40 years (range 19 to 37) and 5 of these had abused inhaled cocaine for about a decade. One patient had abused marijuana, and there was no information on drug usage in the other 7 patient charts. CONCLUSION: Although this is a very small series, we believe there might be a possibility that chronic cocaine exposure predisposes to the development of pancreatic adenocarcinoma. Further studies are necessary.

Respiratory mechanics and morphometry after progressive intraperitoneal effusion.

Respiratory mechanics and thoraco-abdominal morphometry were evaluated in anesthetized, paralyzed, mechanically ventilated rats before and after controlled intraperitoneal injection of warm (37 degrees C) saline. Respiratory system resistances and static elastance were determined in 9 animals using the end inflation occlusion method. Chest wall configuration at both functional residual capacity (FRC) and end inspiration (FRC + VT) was evaluated in: (a) 6 rats by measurements of lateral and anteroposterior diameters, and circumferences at four levels: 3rd intercostal space, xiphoid, subcostal plane and crista iliaca; and (b) 8 rats by measurements of thoracic cephalo-caudal diameter. In addition, FRC changes were measured in 6 rats. Resistances were not altered but static elastance increased progressively. Morphometric changes were similar at both FRC and FRC + VT: cephalo-caudal diameter diminished whereas all other diameters augmented; FRC decreased. In conclusion, intraperitoneal infusion of saline in rats augments elastance, and this is related to a cephalad deviation of the diaphragm plus an increase of the circumferences and diameters of the lower thorax.

Potential of indium-111 to measure inflammatory arthritis.

Since an objective noninvasive method for measuring inflammation in arthritis is lacking, radioimaging experiments were conducted with 111indium-chloride (111InCl3) in the collagen model. A computer imaging index, reflecting uptake in the feet and ankles, was significantly greater in 16 rats immunized with collagen than in 6 nonimmunized rats (mean +/- SEM 1.18 +/- 0.04 vs 0.39 +/- 0.02, for the 2 groups, respectively, p less than 0.001). Additional analyses provided evidence that the 111InCl3 technique can be used to measure objectively progression of the arthritic response of rats of immunization with collagen, and pilot comparisons with conventional bone scintigraphy in 2 patients with rheumatoid arthritis suggested that the method is applicable to human arthritic disease.

Toxicity of drugs used for treatment of rhinitis: a reminder to the otorhinolaryngologist.

We retrospectively studied files on toxicity of drugs used for treatment of rhinitis (nasal antihistamines, oral antihistamines, nasal vasoconstrictors, oral decongestants, nasal corticosteroids, nasal anticholinergic agent, nasal mast cell stabilizer, and respiratory antigen preparations for oral use) that occurred in São Paulo, Brazil, from 1 July 1996 to 30 June 1998. There were 823 cases of toxicity by these agents, with a predominance of oral decongestants (in combination with antihistamines) (53.4%). There was a significant incidence of toxicity within children aged 1 to 4 years (P < 0.05) and a preponderance among males aged 5-9 years and females aged 10-39 years. Accidental intake of medicines accounted for the majority of toxicity cases (57.2%).