Microscopic Surface Structure of Liquid Alkali Metals

We report an x-ray scattering study of the microscopic structure of the surface of a liquid alkali metal. The bulk liquid structure factor of the eutectic K67Na33 alloy is characteristic of an ideal mixture, and so shares the properties of an elemental liquid alkali metal. Analysis of off-specular diffuse scattering and specular x-ray reflectivity shows that the surface roughness of the K-Na alloy follows simple capillary wave behavior with a surface structure factor indicative of surface induced layering. Comparison of thelow-angle tail of the K67Na33 surface structure factor with the one measured for liquid Ga and In previously suggests that layering is less pronounced in alkali metals. Controlled exposure of the liquid to H2 and O2 gas does not affect the surface structure, indicating that oxide and hydride are not stable at the liquid surface under these experimental conditions.Comment: 12 pages, 3 figures, published in Phys. Rev.

Publicly funded home care for older people in Ireland: Determinants of utilisation and policy implications

Background: The majority of older people are independent and self caring. When long-term care is required this is provided across a range of community and residential settings including the older person’s own home. Policy direction and the preference of older people are directed towards supporting older people to remain living in their homes for as long as possible. The majority of home care is provided informally by unpaid carers with a smaller proportion provided formally by paid carers. Formal care is predominantly publicly financed but may be delivered by public, private and not-for-profit organizations. The aim of this study was to identify the determinants of formal home care utilisation amongst community living older people in Ireland. Methodology: The study was cross-sectional in design using data from The Irish Longitudinal Study on Ageing (TILDA). Respondents were interviewed between 2009 and 2011; the response rate was 62%. The behavioural model of health service utilisation provided a framework for the analysis (Aday and Andersen, 1974). Results: Multivariable logistic regression revealed a wide range of factors which predict service utilisation. The strongest determinant of formal home care utilisation was self-reported difficulty with instrumental activities of daily living, followed by older age and living alone. Conclusions: The research provides a population based profile of the characteristics of older adults utilising formal home care services provided by the State. Policy implications include the need for a whole system perspective including standardized access and assessment procedures across the system and a shift in orientation away from domestic care towards greater provision of personal care at home. This study identifies a need to consider home care utilisation in older adults who self-report no limitations in either activities of daily living (ADL) or instrumental activities of daily living (IADL) when modeling the demand for home care in the future

Surface Structure of Liquid Metals and the Effect of Capillary Waves: X-ray Studies on Liquid Indium

We report x-ray reflectivity (XR) and small angle off-specular diffuse scattering (DS) measurements from the surface of liquid Indium close to its melting point of $156^\circ$C. From the XR measurements we extract the surface structure factor convolved with fluctuations in the height of the liquid surface. We present a model to describe DS that takes into account the surface structure factor, thermally excited capillary waves and the experimental resolution. The experimentally determined DS follows this model with no adjustable parameters, allowing the surface structure factor to be deconvolved from the thermally excited height fluctuations. The resulting local electron density profile displays exponentially decaying surface induced layering similar to that previously reported for Ga and Hg. We compare the details of the local electron density profiles of liquid In, which is a nearly free electron metal, and liquid Ga, which is considerably more covalent and shows directional bonding in the melt. The oscillatory density profiles have comparable amplitudes in both metals, but surface layering decays over a length scale of $3.5\pm 0.6$ \AA for In and $5.5\pm 0.4$ \AA for Ga. Upon controlled exposure to oxygen, no oxide monolayer is formed on the liquid In surface, unlike the passivating film formed on liquid Gallium.Comment: 9 pages, 5 figures; submitted to Phys. Rev.

Tetrahedral Symmetry in Ground- and Low-Lying States of Exotic A ~ 110 Nuclei

Recent theoretical calculations predict a possible existence of nuclei with tetrahedral symmetry: more precisely, the mean-field hamiltonians of such nuclei are symmetric with respect to double point-group Td. In this paper, we focus on the neutron-rich Zirconium isotopes as an example and present realistic mean-field calculations which predict tetrahedral ground-state configurations in 108,110Zr and low-lying excited states of tetrahedral symmetry in a number of N > 66 isotopes. The motivations for focusing on these nuclei, as well as a discussion of the possible experimental signatures of tetrahedral symmetry are also presented.Comment: Accepted in Phys. Rev. C - Rapid Communication

Seizure during hyperbaric oxygen therapy for carbon monoxide toxicity: a case series and five-year experience.

BACKGROUND: Hyperbaric oxygen (HBO) therapy is recommended to reduce the delayed neurologic sequelae resulting from carbon monoxide (CO) toxicity. Although HBO is generally well tolerated, there exists a risk of seizure in all patients that may be increased in patients with predisposing factors including: fever, hypothermia, prior seizure, or brain injury. CASE REPORT: We present two cases of patients without known risk factors who experienced seizures associated with HBO therapy during treatment for CO toxicity. CONCLUSION: This facility\u27s 5-year experience and a review of the germane literature are also presented to elucidate the risk factors and incidence of seizures in patients treated with HBO for CO toxicity

Lifetime determination of excited states in Cd-106

Two separate experiments using the Differential Decay Curve Method have been performed to extract mean lifetimes of excited states in 106 Cd. The inedium-spin states of interest were populated by the Mo-98(C-12, 4n) Cd-106 reaction performed at the Wright Nuclear Structure Lab., Yale University. From this experiment, two isomeric state mean lifetimes have been deduced. The low-lying states were populated by the Mo-96(C-13, 3n)Cd-106 reaction performed at the Institut fur Kernphysik, Universitat zu Koln. The mean lifetime of the I-pi = 2(1)(+) state was deduced, tentatively, as 16.4(9) ps. This value differs from the previously accepted literature value from Coulomb excitation of 10.43(9) ps

Molecular Gas, Dust and Star Formation in the Barred Spiral NGC 5383

We present multi-wavelength (interferometer and single-dish CO J=1-0, Halpha, broadband optical and near-infrared) observations of the classic barred spiral NGC 5383. We compare the observed central gas and dust morphology to the predictions of recent hydrodynamic simulations. In the nuclear region, our observations reveal three peaks lying along a S-shaped gas and dust distribution. In contrast, the model predicts a circumnuclear ring, not the observed S-shaped distribution; moreover, the predicted surface density contrast between the central gas accumulation and the bar dust lanes is an order of magnitude larger than observed. The discrepancies are not due to unexplored model parameter space or a nuclear bar but are probably due to the vigorous (7 solar masses per year) star formation activity in the center. As is common in similar bars, the star formation rate in the bar between the bar ends and the central region is low (~0.5 solar masses per yr), despite the high gas column density in the bar dust lanes; this is generally attributed to shear and shocks. We note a tendency for the HII regions to be associated with the spurs feeding the main bar dust lanes, but these are located on the leading side of the bar. We propose that stars form in the spurs, which provide a high column density but low shear environment. HII regions can therefore be found even on the leading side of the bar because the ionizing stars pass ballistically through the dust laneComment: Accepted for publication in The Astrophysical Journal, 33 pages (includes 10 figures

Surface Layering in Liquid Gallium: An X-Ray Reflectivity Study

Surface-induced atomic layering in liquid gallium has been observed using x-ray reflectivity, ultrahigh vacuum conditions, and sputtered clean surfaces. Reflectivity data, collected on a supercooled liquid sample to momentum transfers as large as $q_z$ = 3.0 Å$^{-1}$, exhibit a strong maximum near 2.4 Å$^{-1}$ indicating a layer spacing that is comparable to its atomic dimensions. The amplitude of the electron density oscillations decays with a characteristic length of 6 Å. This is unexpectedly twice that of recent results for Hg, and the difference may be related to covalent bonding or supercooling.Engineering and Applied Science

Tracheobronchomalacia due to amyloidosis in a patient with rheumatoid arthritis

In this case report, we describe a patient with longstanding rheumatoid arthritis who developed tracheobronchomalacia with fatal outcome. Despite negative antemortem biopsies of abdominal fat and tongue, amyloid was found postmortem in the trachea and appeared to be associated with tracheobronchomalacia

Premenopausal endocrine-responsive early breast cancer: who receives chemotherapy?

Background: The role of chemotherapy in addition to combined endocrine therapy for premenopausal women with endocrine-responsive early breast cancer remains an open question, yet trials designed to answer it have repeatedly failed to adequately accrue. The International Breast Cancer Study Group initiated two concurrent trials in this population: in Premenopausal Endocrine Responsive Chemotherapy (PERCHE), chemotherapy use is determined by randomization and in Tamoxifen and Exemestane Trial (TEXT) by physician choice. PERCHE closed with inadequate accrual; TEXT accrued rapidly. Methods: From 2003 to 2006, 1317 patients (890 with baseline data) were randomly assigned to receive ovarian function suppression (OFS) plus tamoxifen or OFS plus exemestane for 5 years in TEXT. We explore patient-related factors according to whether or not chemotherapy was given using descriptive statistics and classification and regression trees. Results: Adjuvant chemotherapy was chosen for 64% of patients. Lymph node status was the predominant determinant of chemotherapy use (88% of node positive treated versus 46% of node negative). Geography, patient age, tumor size and grade were also determinants, but degree of receptor positivity and human epidermal growth factor receptor 2 status were not. Conclusions: The perceived estimation of increased risk of relapse is the primary determinant for using chemotherapy despite uncertainties regarding the degree of benefit it offers when added to combined endocrine therapy in this populatio