Multi-Functional Applications of H-Glass Embedded with Stable Plasmonic Gold Nanoislands.

Metal nanoparticles (MNPs) are synthesized using various techniques on diverse substrates that significantly impact their properties. However, among the substrate materials investigated, the major challenge is the stability of MNPs due to their poor adhesion to the substrate. Herein, it is demonstrated how a newly developed H-glass can concurrently stabilize plasmonic gold nanoislands (GNIs) and offer multifunctional applications. The GNIs on the H-glass are synthesized using a simple yet, robust thermal dewetting process. The H-glass embedded with GNIs demonstrates versatility in its applications, such as i) acting as a room temperature chemiresistive gas sensor (70% response for NO2 gas); ii) serving as substrates for surface-enhanced Raman spectroscopy for the identifications of Nile blue (dye) and picric acid (explosive) analytes down to nanomolar concentrations with enhancement factors of 4.8 × 106 and 6.1 × 105 , respectively; and iii) functioning as a nonlinear optical saturable absorber with a saturation intensity of 18.36 × 1015 W m-2 at 600 nm, and the performance characteristics are on par with those of materials reported in the existing literature. This work establishes a facile strategy to develop advanced materials by depositing metal nanoislands on glass for various functional applications.

Can Electrochemical Impedance Spectroscopy be Replaced by Direct Current Techniques in Battery Diagnosis?

Electrochemical impedance spectroscopy (EIS), a conventional and alternating-current-(AC)-based technique for impedance measurement, is commonly used in battery diagnosis. However, it requires expensive equipment and demanding operating conditions and is complex and model-dependent in data analysis. Recently, novel direct current (DC) analytics have emerged as an alternative to EIS. They are simple yet powerful, being capable of revealing impedance information that traditionally could only be obtained through EIS and determining Li-ion diffusion coefficient. Besides, a complete EIS spectrum can be predicted based on constant current charging curves in the support of machine learning methods. This work highlights the similarities and discrepancies between DC techniques and EIS in the electrochemical analysis of Li-ion batteries. Looking ahead, DC techniques may be a promising substitute for EIS in future battery diagnosis, requiring simplified equipment while offering a deep understanding of battery impedance and its underlying electrochemical processes.

Danish population health measured by the EQ-5D-5L.

AIMS: The aims of this study were to provide Danish population norms for the EQ-5D-5L and to assess the measurement properties of the instrument in a Danish population setting. METHODS: We used data from the Danish 5L valuation study in which a representative sample of the Danish population completed the EQ-5D-5L and answered socio-demographic questions. We generated population norms for the five EQ-5D-5L dimensions, corresponding utility scores and the EQ-5D visual analogue scale (EQ VAS) according to age and sex. Measurement properties of ceiling effects, known-group construct validity and convergent validity were assessed. RESULTS: The mean EQ-5D-5L utility score for the 1014 respondents completing the EQ-5D-5L was 0.90 (standard deviation (SD)=0.16). No significant differences emerged across age groups (minimum mean utility score=0.88 (SD=0.19); maximum mean utility score=0.93 (SD=0.11)) or sex (mean utility score for women=0.89 (SD=0.17); mean utility score for men=0.91 (SD=0.15)). Statistical differences were found across educational level, occupational status, income and living situation. Similar patterns were observed for the EQ VAS. Generally, respondents most often reported problems with pain and discomfort, but young women most often reported problems with anxiety/depression. There was a significant strong correlation between EQ-5D-5L utility and the EQ VAS and a significant correlation between overall health and each of the five EQ-5D-5L dimensions. The overall ceiling effect for the EQ-5D-5L was 39% (compared to 56% for the EQ-5D-3L). CONCLUSIONS: Danish population norms for the EQ-5D-5L are now available. We found fewer ceiling effects for the EQ-5D-5L compared to the EQ-5D-3L, and we provide evidence for convergent and known-group validity of the EQ-5D-5L.

Defensive medicine in Danish general practice. Types of defensive actions and reasons for practicing defensively.

OBJECTIVE: To examine the occurrence of and types of defensive medicine (DM), and the reasons for practicing DM in general practice. DESIGN: Prospective survey registration of consecutive consultations regarding defensive medicine defined as: Actions that are not professionally well founded but are carried out due to demands and pressure. The GPs registered the degree of defensiveness, the type(s) of defensive action(s) and the reason(s) for acting defensively. SETTING: Danish general practice. SUBJECTS: A total of 26 GPs registered a total of 1,758 consultations. MAIN OUTCOME MEASURES: Defensive medical actions. RESULTS: Defensive actions were performed in 12% (210/1749) of all consultations. A fifth (46/210) of the defensive actions were characterised by the GPs as 'moderately' or 'highly' defensive. Frequent types of defensive actions were: blood tests, point-of-care-tests (POCTs) and referrals. Common reasons for defensive actions were: Influence from patients, 37% (78/210), concerns of overlooking severe disease, 32% (67/210) and influence from patient relatives, 12% (25/210). CONCLUSION: Danish GPs registered self-perceived defensive actions in a prospective survey. DM was carried out in one out of eight consultations, most often due to patient influence. The most frequent defensive actions were blood tests, POCTs and referrals.

Test-retest reliability of ICECAP-A in the adult Danish population.

PURPOSE: To investigate the test-retest reliability of Investigating Choice Experiments Capability measure for Adults (ICECAP-A) in the adult Danish population. METHODS: The original English ICECAP-A was translated into Danish by forward-backwards translation using the guidelines by Beaton et al. Three hundred and-thirty-two participants with mean age of 57 years participated in a Web-based study. Data concerning relative and absolute agreement were analysed by the intra-class correlation coefficient and Bland-Altman plot with limits of agreement. The overall and item consistency was investigated by weighted kappa statistics from baseline to 2-week follow-up. Logistic regression was used to study the effect of the sociodemographic characteristics with inconsistent responses as the dependent binary variable. The independent variables were age, sex, education, income, and region of residence at baseline. RESULTS: The baseline ICECAP-A preference-based index score was 0.84, and at follow-up, 0.83. The ICC was 0.86 (95% CI 0.826-0.884), and limits of agreement were 0.164 and - 0.151. The kappa coefficient ranges from 45 to 65%, between random and perfect agreement. The logistic regression to analyse inconsistent responses showed no significant association between the overall index score and sociodemographic characteristics, and no clear pattern was found concerning the individual item inconsistency. CONCLUSIONS: Evidence regarding the reliability of the Danish version of ICECAP-A is satisfactory for both the index score agreement and the individual item consistency and is a reliable measure to be used in a Danish context and future health economic evaluations.

Examining the Heterogeneity and Cost Effectiveness of a Complex Intervention by Segmentation of Patients with Chronic Obstructive Pulmonary Disease.

OBJECTIVES: To examine the heterogeneity in cost-effectiveness analyses of patient-tailored complex interventions. METHODS: Latent class analysis (LCA) was performed on data from a randomized controlled trial evaluating a patient-tailored case management strategy for patients suffering from chronic obstructive pulmonary disease (COPD). LCA was conducted on detailed process variables representing service variation in the intervention group. Features of the identified latent classes were compared for consistency with baseline demographic, clinical, and economic characteristics for each class. Classes for the control group, corresponding to the identified latent classes for the intervention group, were identified using multinomial logistic regression. Cost-utility analyses were then conducted at the class level, and uncertainty surrounding the point estimates was assessed by probabilistic sensitivity analysis. RESULTS: The LCA identified three distinct classes: the psychologically care class, the extensive COPD care class, and the limited COPD care class. Patient baseline characteristics were in line with the features identified in the LCA. Evaluation of cost-effectiveness revealed highly disparate results, and case management for only the extensive COPD care class appeared cost-effective with an incremental cost-effectiveness ratio of £26,986 per quality-adjusted life-year gained using the threshold value set by the National Institute of Health and Care Excellence. CONCLUSIONS: Findings indicate that researchers evaluating patient-tailored complex interventions need to address both supply-side variation and demand-side heterogeneity to link findings with outcome. The article specifically proposes the use of LCA because it is believed to have the potential to enable more appropriate targeting of complex care strategies.

A qualitative exploration of early assessment of innovative medical technologies.

BACKGROUND: Hospitals increasingly make decisions about early development of and investment in innovative medical technologies (IMTs), but at present often without an early assessment of their potential to ensure selection of the most promising candidates for further development. This paper explores how early assessment is carried out in different health organisations and then discusses relevant learning points for hospitals. METHODS: A qualitative study design with a structured interview guide covering four themes was used. Content analyses of interview notes were performed covering four predetermined themes: context, basis for decision-making, process and structure, and perceptions. A fifth theme, handling cognitive bias, was identified during data analysis. RESULTS: A total of 11 organisations participated; eight from the private health industry and three public hospitals. The interviews identified four areas in which early assessment is performed in similar manner across the studied organisations and four areas where differences exist between public hospitals and private organisations. Public hospitals indicate a lower degree of formalised early assessment and less satisfaction with how early assessment is performed, compared to private organisations. Based on the above findings, two learning points may carry promise for hospitals. First, having dedicated prioritising committees for IMTs making stop/go decisions. This committee is separate from the IMT development processes and involved staff. Secondly, the committee should base decisions on a transparent early assessment decision-support tool, which include a broad set of domains, is iterative, describes uncertainty, and minimise cognitive biases. CONCLUSIONS: Similarities and differences in the way early assessment is done in different health organisations were identified. These findings suggest promising learning points for the development of an early assessment model for hospitals.

General practitioners' attitudes towards and experiences with referrals due to supplemental health insurance.

Background: Supplemental health insurances (SHI) cover 38% of the Danish population. SHI can give faster access to, and additional treatment from, private health providers. However, this is contingent on a referral from the general practitioner (GP), further complicating clinical decision-making. Objectives: To describe GPs' attitudes to SHI and their experiences with patients holding SHI. Moreover, we analysed associations between different GP characteristics; e.g. gender, age, practice type, own SHI status and their attitudes to and experiences with SHI. Methods: A questionnaire was mailed to 3321 GPs focusing on three issues: (i) Attitudes towards the public health care system. (ii) Perceptions of the impact of SHI. (iii) Experiences with patients holding SHIs. Results: The response rate was 64%. Overall, GPs found that SHIs contribute to inequality (83%) and overtreatment (90%). However, 46% often feel under pressure to refer SHI patients to specialist care, even though not medically indicated, while 11% always or often refer SHI patients unconditionally. Both groups perceive SHI patients more insistent on getting referrals than patients without SHI. Conclusion: Even though a majority of GPs associate SHI with overtreatment and inequality in health, many GPs feel under pressure to refer patients holding SHI for treatments or examinations that are not medically warranted. Some GPs even refer these patients without further examination or questioning. Insistent SHI patients may partly explain this paradox. Future research should illuminate SHI patients' courses in the private as well as the public healthcare system with regards to medical indications and health outcome measures focusing on inequality and overtreatment.

High-output LED-based light engine for profile lighting fixtures with high color uniformity using freeform reflectors.

In the stage lighting and entertainment market, light engines (LEs) for lighting fixtures are often based on high-intensity discharge (HID) bulbs. Switching to LED-based light engines gives possibilities for fast switching, additive color mixing, a longer lifetime, and potentially, more energy-efficient systems. The lumen output of a single LED is still not sufficient to replace an HID source in high-output profile fixtures, but combining multiple LEDs can create an LE with a similar output, but with added complexity. This paper presents the results of modeling and testing such a light engine. Custom ray-tracing software was used to design a high-output red, green and blue LED-based light engine with twelve CBT-90 LEDs using a dual-reflector principle. The simulated optical system efficiency was 0.626 with a perfect (R=1) reflector coating for light delivered on a target surface through the entire optical system. A profile lighting fixture prototype was created, and provided an output of 6744 lumen and an efficiency of 0.412. The lower efficiency was mainly due to a non-optimal reflector coating, and the optimized design is expected to reach a significantly higher efficiency.

Second-harmonic scanning microscopy of domains in Al wire bonds in IGBT modules.

Scanning second harmonic generation microscopy has been used to investigate crystallographic orientation of the grain structure in Al wire bonds in insulated gate bipolar transistor modules. It was shown that the recorded second harmonic microscopy images revealed the grain structure of the Al sample. Additional information of the individual grain orientation was achieved by using simple interpretations of the recorded rotational anisotropy.

Near-infrared tailored thermal emission from wafer-scale continuous-film resonators.

We experimentally investigate the near-infrared emission from simple-to-fabricate, continuous-film Fabry-Perot-type resonators, consisting only of unstructured dielectric and metallic films. We show that the proposed configuration is suitable for realization of narrowband emitters, tunable in ranges from mid- to near-infrared, and demonstrate emission centered at the wavelength of 1.7 µm, which corresponds to the band gap energy of GaSb-based photodetectors. The emission is measured at 748 K and follows well the emissivity as predicted from reflection measurements and Kirchhoff's reciprocity. The considered emitter configuration is spectrally highly tunable and, consisting of only few unstructured layers, is amenable to wafer-scale fabrication at low cost by use of standard deposition procedures.

Surface plasmon polariton excitation by second harmonic generation in single organic nanofibers.

Coherent local excitation of surface plasmon polaritons (SPPs) by second-harmonic generation (SHG) in individual aligned crystalline organic functionalized para-phenylene nanofibers deposited on a thin silver film is demonstrated. The SH-SPP generation is considered theoretically and investigated experimentally with angular-resolved leakage radiation spectroscopy for normal incidence of the excitation beam. Both measurements and simulations show asymmetric excitation of left- and right-propagating SH-SPPs, which is explained as an effect of fiber molecules being oriented at an angle relative to the silver film surface.

Compact wavelength add-drop multiplexers using Bragg gratings in coupled dielectric-loaded plasmonic waveguides.

We report a novel design of a compact wavelength add-drop multiplexer utilizing dielectric-loaded surface plasmon-polariton waveguides (DLSPPWs). The DLSPPW-based configuration exploits routing properties of directional couplers and filtering abilities of Bragg gratings. We present practical realization of a 20-µm-long device operating at telecom wavelengths that can reroute optical signals separated by approximately 70 nm in the wavelength band. We characterize the performance of the fabricated structures using scanning near-field optical microscopy as well as leakage-radiation microscopy and support our findings with numerical simulations.

Hearing Loss, Hearing Aid Use, and Risk of Dementia in Older Adults.

Importance: Hearing loss has been suggested as a risk factor for dementia, but there is still a need for high-quality research to better understand the association between these 2 conditions and the underlying causal mechanisms and treatment benefits using larger cohorts and detailed data. Objective: To investigate the association between hearing loss and incident dementia, as well as how hearing aid use contributes to this association. Design, Setting, and Participants: This population-based cohort study was conducted in Southern Denmark between January 2003 and December 2017 and included all residents 50 years and older. We excluded all persons with dementia before baseline as well as those who did not live in the region 5 years before baseline, with incomplete address history, or who had missing covariate information. Exposures: Individual hearing status based on the Hearing Examinations in Southern Denmark database, which contains data on all pure-tone audiometry examinations performed at public hearing rehabilitation clinics in Southern Denmark. Main Outcomes and Measures: Incident cases of dementia and Alzheimer disease as identified from national registries. Results: The study population comprised 573 088 persons (298 006 women [52%]; mean [SD] age, 60.8 [11.3] years) with 23 023 cases of dementia and mean (SD) follow-up of 8.6 (4.3) years. Having a hearing loss was associated with an increased risk of dementia, with an adjusted hazard ratio (HR) of 1.07 (95% CI, 1.04-1.11) compared with having no hearing loss. Severe hearing loss in the better and worse ear was associated with a higher dementia risk, with an HR of 1.20 (95% CI, 1.09-1.32) and 1.13 (95% CI, 1.06-1.20), respectively, compared with having no hearing loss in the corresponding ear. Compared with people without hearing loss, the risk of dementia was higher among people with hearing loss who were not using hearing aids than those who had hearing loss and were using hearing aids, with HRs of 1.20 (95% CI, 1.13-1.27) and 1.06 (95% CI, 1.01-1.10), respectively. Conclusions and Relevance: The results of this cohort study suggest that hearing loss was associated with increased dementia risk, especially among people not using hearing aids, suggesting that hearing aids might prevent or delay the onset and progression of dementia. The risk estimates were lower than in previous studies, highlighting the need for more high-quality longitudinal studies.

Pore size dependence of diffuse light scattering from anodized aluminum solar cell backside reflectors.

The development of backside reflectors (BSRs) is crucial for the efficiency of future low cost thin-film silicon solar cells. In this work, the scattering efficiency of bare aluminum BSRs with different pore sizes and ordering of surface microstructures are investigated. The BSRs were fabricated by utilizing the process of self-ordering anodic oxidation on aluminum foils resulting in regions with an approximately hexagonally periodic surface microstructure. It was found that the total and diffuse light scattering reflectance spectra showed opposite tendencies when increasing the pore size of the microstructures. When the pore size was increased to 700 nm, more than 68% of the incident light with wavelengths from 250 nm to 800 nm was reflected by scattering. For a similar geometry, except that it had less ordering, this number was increased to around 80%. This large fraction of reflected light observed in the form of scattering is promising for the use of the considered geometries as BSRs in thin-film silicon solar cells.

Iridium-Based Selective Emitters for Thermophotovoltaic Applications.

The long-term operation of refractory-metal-based metamaterials is crucial for applications such as thermophotovoltaics. The metamaterials based on refractory metals like W, Mo, Ta, Nb, and Re fail primarily by oxidation. Here, the use of the noble metal Ir is proposed, which is stable to oxidation and has optical properties comparable to gold. The thermal endurance of Ir in a 3-layer-system, consisting of HfO2 /Ir/HfO2 , by performing annealing experiments up to 1240 °C in a pressure range from 2 × 10-6  mbar to 1 bar, is demonstrated. The Ir layer shows no oxidation in a vacuum and inert gas atmosphere. At temperatures above 1100 °C, the Ir layer starts to agglomerate due to the degradation of the confining HfO2 layers. An in situ X-ray diffraction experimental comparison between 1D multilayered Ir/HfO2 and W/HfO2 selective emitters annealed at 1000 °C, 2 × 10-6  mbar, over 100 h, confirms oxidation stability of Ir while W multilayers gradually disappear. The results of this work show that W-based metamaterials are not long-term stable even at 1000 °C. However, the oxidation resistance of Ir can be leveraged for refractory plasmonic metamaterials, such as selective emitters in thermophotovoltaic systems with strong suppression of long wavelength radiation.

Second-harmonic generation from electron beam deposited SiO films.

It is demonstrated that as-grown e-beam deposited SiOx thin films on fused silica substrates show a second-order nonlinear response that is dependent on film thickness. Using a Maker fringes method the effective nonlinear coefficient for a SiO thin film is estimated to be comparable to that of crystalline quartz. Variation of process parameters has been used to investigate the origin of the nonlinear response. The second-harmonic signal is very sensitive to annealing of the film and can be totally removed by annealing at a few hundred degrees. It is also demonstrated that a retarding grid that traps charged particles between the crucible and the sample reduces the nonlinear signal from a SiO thin film significantly. It is suggested that oriented dipoles arise during deposition due to a negatively charged film from oxygen ions, thus, resulting in a non-centrosymmetric film. Finally, using e-beam lithography, well-defined nonlinear 2D structures can be synthesized, thus opening the door to a new and practical way to create nonlinear structures for planar waveguide technology.

Polarization-resolved two-photon luminescence microscopy of V-groove arrays.

Using two-photon luminescence (TPL) microscopy and local reflection spectroscopy we investigate electromagnetic field enhancement effects from a µm-sized composition of 450-nm-deep V-grooves milled by focused ion beam in a thick gold film and assembled to feature, within the same structure, individual V-grooves as well as one- and two-dimensional 300-nm-period arrays of, respectively, parallel and crossed V-grooves. We analyze TPL signal levels obtained at different spatial locations and with different combinations of excitation and detection polarizations, discovering that the TPL emitted from the V-grooves is polarized in the direction perpendicular to that of the V-grooves. This feature implies that the TPL occurs solely in the form of (p-polarized) surface plasmon modes and originates therefore from the very bottom of V-grooves, where no photonic modes exist. Implications of the results obtained to evaluation of local field enhancements using TPL microscopy, especially when investigating extended structures exhibiting different radiation channels, are discussed.

Reliability of point source approximations in compact LED lens designs.

In many applications, compact concentrator lenses are used for collimating light from LEDs into high output beams. When optimizing lens designs, the LED is often approximated as a point source. At small lens-to-LED size ratios this is known to be inaccurate, but the performance compared to optimizations with more realistic models is rarely addressed. This paper examines the reliability of a point source model in compact lens design by comparing with optimisations that use a factory measured LED ray-file. The point source is shown to cause significant, unnecessary efficiency loss even at large lens sizes, while the use of a ray-file allows for a >55% reduction in the footprint area of the lens. The use of point source approximations in compact lens designs is therefore generally discouraged.

Nanoparticle plasmon resonances in the near-static limit.

Localized surface plasmon resonances of metal nanoparticles of arbitrary shape are analyzed in the near-static limit with retardation included to the second order. Starting from the electrostatic approximation, the second-order correction to the resonant dielectric constant is expressed by means of a triple surface integral. For arbitrary nanoparticles with cylindrical symmetry we show how the triple surface integral can be significantly simplified, resulting in a computationally efficient scheme for evaluation of nanoparticle plasmon eigenresonances in the near-static limit. The approach allows for calculation of both dipolar and higher-order resonances.