Nutrition process improvements for adult inpatients with inborn errors of metabolism using the i-PARIHS framework

This project aimed to implement consensus recommendations and innovations that improve dietetic services to promote timely referral to optimise nutritional management for adult inpatients with inborn errors of metabolism (IEM).The i-PARIHS framework was used to identify service gaps, implement innovations and evaluate the innovations within this single-site study. The constructs of this framework are: (i) review of the evidence; (ii) recognising patients and staff knowledge and attitudes; (iii) acknowledging the local context; and (iv) the facilitators role. This included a literature review and metabolic centre service comparisons to investigate dietetic referral and foodservice processes to inform the innovation. A 12-month chart audit (6 months retrospective and prospective of implemented innovation, respectively) to evaluate newly established dietetic referral and IEM nutrition provision procedures was also completed.The innovations implemented encompassed a clinical alert triggering urgent referral, nutrition sick day plans and metabolic diet and formula prescription via an 'alert' tab in electronic records. Eleven metabolic protein-restricted diets and nine formula recipes were introduced. Prior to the innovations, only 53% (n = 19/36) of inpatients with IEM were assessed by the dietitian and received appropriate nutrition within 24 hours. Following implementation of the innovations, 100% (n = 11/11) of inpatients with IEM received timely dietetic assessment and therapeutic nutrition.Implementation of innovations developed using the i-PARIHS framework is effective in timely notification of the metabolic dietitian of referrals. This ensures optimal nutritional management during admissions which is required in this group of high-risk patients

Investigation of Polymer–Plasticizer Blends as SH-SAW Sensor Coatings for Detection of Benzene in Water with High Sensitivity and Long-Term Stability

We report the first-ever direct detection of benzene in water at concentrations below 100 ppb (parts per billion) using acoustic wave (specifically, shear-horizontal surface acoustic wave, SH-SAW) sensors with plasticized polymer coatings. Two polymers and two plasticizers were studied as materials for sensor coatings. For each polymer–plasticizer combination, the influence of the mixing ratio of the blend on the sensitivity to benzene was measured and compared to commercially available polymers that were used for BTEX (benzene, toluene, ethylbenzene, and xylene) detection in previous work. After optimizing the coating parameters, the highest sensitivity and lowest detection limit for benzene were found for a 1.25 μm thick sensor coating of 17.5%-by-weight diisooctyl azelate-polystyrene on the tested acoustic wave device. The calculated detection limit was 45 ppb, with actual sensor responses to concentrations down to 65 ppb measured directly. Among the sensor coatings that showed good sensitivity to benzene, the best long-term stability was found for a 1.0 μm thick coating of 23% diisononyl cyclohexane-1,2-dicarboxylate-polystyrene, which was studied here because it is known to show no detectable leaching in water. The present work demonstrates that, by varying type of plasticizer, mixing ratio, and coating thickness, the mechanical and chemical properties of the coatings can be conveniently tailored to maximize analyte sorption and partial chemical selectivity for a given class of analytes as well as to minimize acoustic-wave attenuation in contact with an aqueous phase at the operating frequency of the sensor device

Fermi-Edge Superfluorescence from a Quantum-Degenerate Electron-Hole Gas

We report on the observation of spontaneous bursts of coherent radiation from a quantum-degenerate gas of nonequilibrium electron-hole pairs in semiconductor quantum wells. Unlike typical spontaneous emission from semiconductors, which occurs at the band edge, the observed emission occurs at the quasi-Fermi edge of the carrier distribution. As the carriers are consumed by recombination, the quasi-Fermi energy goes down toward the band edge, and we observe a continuously red-shifting streak. We interpret this emission as cooperative spontaneous recombination of electron-hole pairs, or superfluorescence, which is enhanced by Coulomb interactions near the Fermi edge. This novel many-body enhancement allows the magnitude of the spontaneously developed macroscopic polarization to exceed the maximum value for ordinary superfluorescence, making electron-hole superfluorescence even more "super" than atomic superfluorescence.Comment: 10 pages, 5 figure

HgSe, a highly electronegative stable metallic contact for semiconductor devices

Schottky barriers formed by the highly electronegative substance HgSe on n-ZnS and on n-ZnSe have been characterized by capacitance-voltage and photoresponse measurements. The barriers are about 0.5 eV greater than Au barriers on these n-type substrates. HgSe contacts are stable under ambient conditions and are easily fabricated, making them attractive for device use

Direct interelectrode tunneling in GaSe

Using thin films of the layer compound gallium selenide, we have fabricated experimental structures which are nearly ideal for the study of tunneling currents. All of the parameters relevant to current flow in these structures can be independently determined since single-crystal gallium selenide films have the properties of the bulk material and also well-defined interfaces. A new analytical technique for determining the energy-momentum dispersion relation within the forbidden gap of a solid is discussed and applied to current-voltage data obtained from metal-GaSe-metal structures. The resulting E-k relation is shown to be an intrinsic property of GaSe. Tunneling currents in GaSe are shown to be quantitatively understood in terms of this E-k relation, the geometry of a given structure, and a simple model of current flow via tunneling

Radial Redshift Space Distortions

The radial component of the peculiar velocities of galaxies cause displacements in their positions in redshift space. We study the effect of the peculiar velocities on the linear redshift space two point correlation function. Our analysis takes into account the radial nature of the redshift space distortions and it highlights the limitations of the plane parallel approximation. We consider the problem of determining the value of \beta and the real space two point correlation function from the linear redshift space two point correlation function. The inversion method proposed here takes into account the radial nature of the redshift space distortions and can be applied to magnitude limited redshift surveys that have only partial sky coverage.Comment: 26 pages including 11 figures, to appear in Ap

Optical Reflection Studies of Damage in Ion Implanted Silicon

Optical (3–6.5 eV) reflection spectra are presented for crystalline Si implanted at room temperature with 40 keV Sb ions to doses of less than 2×10^15/cm^2. These spectra, and their deviation from the reflection spectrum of crystalline Si, are discussed in terms of a model based on the average dielectric properties of the implanted region. For samples having a high ion dose (>10^15/cm^2) the observed spectra resemble the spectra of sputtered Si films. Anneal characteristics of the reflection spectra are found to be dose dependent. These observations are compared to, and found to substantiate, the results of other experimental techniques for studying lattice damage in Si