Multiple Shape Coexistence in

From detailed spectroscopy of ^{110}Cd and ^{112}Cd following the ß^{+}/electron-capture decay of ^{110,112}In and the ß^{-} decay of ^{112}Ag, very weak decay branches from nonyrast states are observed. The transition rates determined from the measured branching ratios and level lifetimes obtained with the Doppler-shift attenuation method following inelastic neutron scattering reveal collective enhancements that are suggestive of a series of rotational bands. In ^{110}Cd, a γ band built on the shape-coexisting intruder configuration is suggested. For ^{112}Cd, the 2^{+} and 3^{+} intruder γ-band members are suggested, the 0_{3}^{+} band is extended to spin 4^{+}, and the 0_{4}^{+} band is identified. The results are interpreted using beyond-mean-field calculations employing the symmetry conserving configuration mixing method with the Gogny D1S energy density functional and with the suggestion that the Cd isotopes exhibit multiple shape coexistence.

Collective structure in 94Zr and subshell effects in shape coexistence.

Based on results from a measurement of weak decay branches observed following the ß- decay of 94Y and on lifetime data from a study of 94Zr by inelastic neutron scattering, collective structure is deduced in the closed-subshell nucleus 94Zr. These results establish shape coexistence in 94Zr. The role of subshells for nuclear collectivity is suggested to be important.

New features of shape coexistence in ;{152}Sm.

Excited states in ;{152}Sm have been investigated with the ;{152}Sm(n,n;{'}gamma) reaction. The lowest four negative-parity band structures have been characterized in detail with respect to their absolute decay properties. Specifically, a new K;{pi} = 0;{-} band has been assigned with its 1;{-} band head at 1681 keV. This newly observed band has a remarkable similarity in its E1 transition rates for decay to the first excited K;{pi} = 0;{+} band at 684 keV to the lowest K;{pi} = 0;{-} band and its decay to the ground-state band. Based on these decay properties, as well as energy considerations, this new band is assigned as a K;{pi} = 0;{-} octupole excitation based on the K;{pi} = 0_{2};{+} state. An emerging pattern of repeating excitations built on the 0_{2};{+} level similar to those built on the ground state may indicate that ;{152}Sm is a complex example of shape coexistence rather than a critical point nucleus.

Identification of mixed-symmetry states in an odd-mass nearly spherical nucleus.

The low-spin structure of 93Nb has been studied using the (n,n'gamma) reaction at neutron energies ranging from 1.5 to 3 MeV and the 94Zr(p,2ngamma)93Nb reaction at bombarding energies from 11.5 to 19 MeV. States at 1779.7 and 1840.6 keV, respectively, are proposed as mixed-symmetry states associated with the pi2p(1/2)-1x(2(1),MS+,94Mo) coupling. These assignments are derived from the observed M1 and E2 transition strengths to the 2p(1/2)-1x(2(1)+,94Mo) symmetric one-phonon states, energy systematics, spins and parities, and comparison with shell model calculations.

Pulmonary remodeling in asthma.

For many years it was assumed that all asthmatics had an at least potentially reversible disease. It is now clear both from longitudinal studies of FEV1 and biopsy data that some asthmatics develop permanent obstructive lung disease. Some adults exhibit an accelerated decline in lung function, and some children never reach normal lung volume. The most likely histologic changes accounting for this phenomena are the deposition of collagen and glycoprotein beneath the basement membrane and in the extracellular matrix, and the destruction of elastic tissue. This permanent obstruction does not occur in all asthmatics. Factors that place patients at increased risk appear to be related to the severity and the duration of the disease and the degree of bronchial hyperresponsiveness. It is unclear, based upon present data, as to whether or not inhaled corticosteroids can favorably affect the process of remodeling, but evidence seems to favor this hypothesis. Inhaled corticosteroids, in some studies, have been shown to decrease the thickness of the lamina reticularis and retard the decline in FEV1. In addition, removal of the source of asthma, as demonstrated in occupational asthma due to toluene diisocyanate, can have a beneficial effect in this regard.

Sexually transmitted disease screening and reporting practices in a military medical center.

Sexually transmitted diseases (STDs) and their sequelae are responsible for significant human and economic costs. Military personnel are one of many core populations at increased risk for acquiring STDs. This study was designed to assess primary care physician/practitioner compliance with secondary screening recommendations and reporting practices of STDs in a military setting. Data from approximately 27,000 covered lives from the Naval Hospital and the Naval Air Station Branch Medical Clinic in Jacksonville, Florida, were used in this analysis. Because chlamydia is the most prevalent STD, laboratory results indicative of infection with chlamydia from July 1 to December 31, 1996, were used as a marker of a patient population requiring additional (secondary) STD screening. Patients with laboratory-confirmed chlamydia infection were identified using the Composite Health Care System. The medical records of these index cases were then analyzed for the presence of laboratory test results of human immunodeficiency virus (HIV), rapid plasma reagin, and hepatitis B virus (HBV) within 6 months of a positive chlamydia test. To assess compliance with mandated reporting of particular STDs, total laboratory-confirmed cases of chlamydia, syphilis, and HBV were compared with total cases reported to the Office of Preventive Medicine at the Bureau of Medicine and Surgery, U.S. Navy, during a 1-year period from July 1, 1996, to June 30, 1997. In 32% of chlamydia cases, no additional laboratory tests for HIV, syphilis, or HBV were obtained within 6 months. Fourteen percent of chlamydia cases were reported to the Office of preventive Medicine. Compliance with screening for multiple STDs after the identification of a single STD should be improved. In addition, better methods for reporting cases of STDs should be implemented.

Physostigmine in the treatment of gamma-hydroxybutyric acid overdose.

The widespread abuse of the recreational drug gamma-hydroxybutyric acid has resulted in several reports of overdose leading to coma. The use of a short-acting anticholinesterase agent such as physostigmine as a potential reversal agent has been proposed previously. We report 2 cases of gamma-hydroxybutyric acid-induced coma that rapidly reversed with intravenous administration of physostigmine.

Nuclear Structure Studies With the Inelastic Neutron Scattering Reaction and Gamma-Ray Detection.

The (n,n'γ) reaction has been used at the University of Kentucky accelerator facility to examine the detailed structure of a number of nuclei. The advantages of this method are reviewed, and recent developments are described. Examples of unique nuclear structure studies that have been carried out with this method are presented.

Toxic ingestion of gamma-hydroxybutyric acid.

Gamma-hydroxybutyric acid (GHB) has become a popular new drug of abuse. Its effects include euphoria and disinhibition. Recently, several cases have been reported in the literature of life-threatening or lethal ingestions. We report the case of a 17-year-old male who became unresponsive after taking GHB. Gamma-hydroxybutyric acid is used outside the United States to treat narcolepsy. In the past, it was touted as a muscle-bulking aid and was taken by body-builders. It has also been implicated as a drug involved in "date-rapes." Patients who ingest excessive GHB have a markedly altered level of consciousness, as did the patient in this illustrative case. Neostigmine and physostigmine show promise as potential reversal agents. Gamma-hydroxybutyric acid overdose should be considered in any patient with altered mental status and a history of recreational drug abuse.

Asthma: the irreversible airways disease.

Chronic inflammation of the asthmatic airway leads to epithelial desquamation, goblet cell hyperplasia, mucosal and submucosal inflammation, prominent smooth muscle, and collagen deposition below the basement membrane. The changes in the airway are attributed to chronic inflammation, the healing process and subsequent remodeling. These changes contribute to three predominant mechanisms of increased airway resistance in asthma: decreased elastance of airways; increased smooth muscle in the airway which may cause increased narrowing during bronchospasm; and collagen deposition beneath the basement membrane resulting in airway wall thickening. Destruction and subsequent remodeling of the normal bronchial architecture are manifested by a progressive decline in FEV1. In an attempt to decrease the progressive decline in FEV1, studies on proper therapy have been undertaken. Antiinflammatory medications, such as inhaled corticosteroids, have been shown to decrease this rate of decline in lung function, while the effect of bronchodilators is less conclusive. Beginning treatment with inhaled corticosteroids early produces a better clinical response compared to initiating treatment late, and early treatment may prevent airway remodeling and development of irreversible structural changes.

Calculation of inhibitor Ki and inhibitor type from the concentration of inhibitor for 50% inhibition for Michaelis-Menten enzymes.

The use of I50 (concentration of inhibitor required for 50% inhibition) for enzyme or drug studies has the disadvantage of not allowing easy comparison among data from different laboratories or under different substrate conditions. Modifications of the Michaelis-Menten equation for treatment of inhibitors can allow both the determination of the type of inhibition (competitive, noncompetitive, and uncompetitive) and the Ki for the inhibitor. For competitive and uncompetitive inhibitors when the assay conditions are [S] = Km, then Ki = I50/2. For different conditions of [S] there is a divergence between competitive and uncompetitive inhibitors that may be used to identify the type of inhibitor. The equation for Ki also differs. For noncompetitive inhibitors the Ki = I50 and this relationship is valid with changing [S]. The equations developed require a single substrate, reversible-type inhibitors, and kinetics of the Michaelis-Menten type. Examples of the use of the equations are illustrated with experimental data from scientific publications.