Determination of complex dielectric functions of ion implanted and implanted‐annealed amorphous silicon by spectroscopic ellipsometry

Measuring with a spectroscopic ellipsometer (SE) in the 1.8–4.5 eV photon energy region we determined the complex dielectric function (ϵ = ϵ1 + iϵ2) of different kinds of amorphous silicon prepared by self‐implantation and thermal relaxation (500 °C, 3 h). These measurements show that the complex dielectric function (and thus the complex refractive index) of implanted a‐Si (i‐a‐Si) differs from that of relaxed (annealed) a‐Si (r‐a‐Si). Moreover, its ϵ differs from the ϵ of evaporated a‐Si (e‐a‐Si) found in the handbooks as ϵ for a‐Si. If we use this ϵ to evaluate SE measurements of ion implanted silicon then the fit is very poor. We deduced the optical band gap of these materials using the Davis–Mott plot based on the relation: (ϵ2E2)1/3 ∼ (E− Eg). The results are: 0.85 eV (i‐a‐Si), 1.12 eV (e‐a‐Si), 1.30 eV (r‐a‐Si). We attribute the optical change to annihilation of point defects

Cool city mornings by urban heat

The urban heat island effect is a phenomenon observed worldwide, i.e. evening and nocturnal temperatures in cities are usually several degrees higher than in the surrounding countryside. In contrast, cities are sometimes found to be cooler than their rural surroundings in the morning and early afternoon. Here, a general physical explanation for this so-called daytime urban cool island (UCI) effect is presented and validated for the cloud-free days in the BUBBLE campaign in Basel, Switzerland. Simulations with a widely evaluated conceptual atmospheric boundary-layer model coupled to a land-surface model, reveal that the UCI can form due to differences between the early morning mixed-layer depth over the city (deeper) and over the countryside (shallower). The magnitude of the UCI is estimated for various types of urban morphology, categorized by their respective local climate zones

Noble-gas ion bombardment on clean silicon surfaces

Under UHV conditions clean c-Si(111) surfaces have been bombarded at room temperature by noble gases (He,Ne,Ar,Kr). Using spectroscopic ellipsometry, the implantation processes were continuously recorded. A low-dose behavior (amorphization) and a high-dose behavior (dilution) are observed. After termination of the bombardment, a self-anneal behavior appears and some experiments are discussed in order to explain the observed phenomena. After applying a monotonous temperature increase up to 1100 K, the noble gas desorbs and the surface layer returns to the original state, as can be seen from a closed trajectory in the (δψ,δΔ) plane. The low-dose behavior is analyzed in the scope of a simple ellipsometric first-order approximation, and the results obtained are compared with theory. The dilution arising during the high-dose behavior can be explained ellipsometrically by means of microscopic surface roughness, and some complementary measurements are reported to verify this explanation

Evaluation of uncertainties in regional climate change simulations

We have run two regional climate models (RCMs) forced by three sets of initial and boundary conditions to form a 2×3 suite of 10-year climate simulations for the continental United States at approximately 50 km horizontal resolution. The three sets of driving boundary conditions are a reanalysis, an atmosphere-ocean coupled general circulation model (GCM) current climate, and a future scenario of transient climate change. Common precipitation climatology features simulated by both models included realistic orographic precipitation, east-west transcontinental gradients, and reasonable annual cycles over different geographic locations. However, both models missed heavy cool-season precipitation in the lower Mississippi River basin, a seemingly common model defect. Various simulation biases (differences) produced by the RCMs are evaluated based on the 2×3 experiment set in addition to comparisons with the GCM simulation. The RCM performance bias is smallest, whereas the GCM-RCM downscaling bias (difference between GCM and RCM) is largest. The boundary forcing bias (difference between GCM current climate driven run and reanalysis-driven run) and intermodel bias are both largest in summer, possibly due to different subgrid scale processes in individual models. The ratio of climate change to biases, which we use as one measure of confidence in projected climate changes, is substantially larger than 1 in several seasons and regions while the ratios are always less than 1 in summer. The largest ratios among all regions are in California. Spatial correlation coefficients of precipitation were computed between simulation pairs in the 2×3 set. The climate change correlation is highest and the RCM performance correlation is lowest while boundary forcing and intermodel correlations are intermediate. The high spatial correlation for climate change suggests that even though future precipitation is projected to increase, its overall continental-scale spatial pattern is expected to remain relatively constant. The low RCM performance correlation shows a modeling challenge to reproduce observed spatial precipitation patterns

Routine versus on demand removal of the syndesmotic screw; a protocol for an international randomised controlled trial (RODEO-trial)

Background: Syndesmotic injuries are common and their incidence is rising. In case of surgical fixation of the syndesmosis a metal syndesmotic screw is used most often. It is however unclear whether this screw needs to be removed routinely after the syndesmosis has healed. Traditionally the screw is removed after six to 12 weeks as it is thought to hamper ankle functional and to be a source of pain. Some studies however suggest this is only the case in a minority of patients. We therefore aim to investigate the effect of retaining the syndesmotic screw on functional outcome. Design: This is a pragmatic international multicentre randomised controlled trial in patients with an acute syndesmotic injury for which a metallic syndesmotic screw was placed. Patients will be randomised to either routine removal of the syndesmotic screw or removal on demand. Primary outcome is functional recovery at 12 months measured with the Olerud-Molander Score. Secondary outcomes are quality of life, pain and costs. In total 194 patients will be needed to demonstrate non-inferiority between the two interventions at 80% power and a significance level of 0.025 including 15% loss to follow-up. Discussion: If removal on demand of the syndesmotic screw is non-inferior to routine removal in terms of functional outcome, this will offer a strong argument to adopt this as standard practice of care. This means that patients will not have to undergo a secondary procedure, leading to less complications and subsequent lower costs.Peer reviewe

Routine versus on demand removal of the syndesmotic screw; a protocol for an international randomised controlled trial (RODEO-trial) (vol 19, 35, 2018)

Peer reviewe

Adjuvant immunotherapy in older patients with stage III and resected stage IV melanoma:Toxicity and recurrence-free survival outcomes from the Dutch melanoma treatment registry

Background: Adjuvant anti-PD-1 therapy improves relapse free survival in stage III melanoma, but also leads to immune-related adverse events (irAEs). Older patients are of particular interest due to comorbidities and frailty, which may impact their ability to tolerate irAEs and benefit from anti-PD-1 therapy. This study aimed to explore associations between clinical parameters and the occurrence of grade ≥ 3 irAEs and recurrence-free survival (RFS) in older patients with radically resected stage III/IV cutaneous melanoma treated with adjuvant anti-PD-1 therapy. Methods: Patients aged ≥ 65 with resected stage III/IV cutaneous melanoma treated with adjuvant anti-PD-1 therapy between 2018 and 2022 were selected using real-world data from the nationwide Dutch Melanoma Treatment Registry (DMTR). A univariate and multivariable logistic regression was used to compare determinants of grade ≥ 3 irAEs, and univariate and multivariable Cox-proportional hazard models were fitted to identify factors influencing RFS.Results: The study included 885 patients, with 280 aged 75 and older. The incidence of grade ≥ 3 irAEs was 15.5 % in the 65–74 age group and 13.9 % in the ≥ 75 age group. No significant correlation was found between age and grade ≥ 3 irAEs. However, an increasing number of comorbidities was associated with a higher risk of grade ≥ 3 irAEs (multivariable analyses: OR 1.83, 95 % C.I. 0.99–3.40). The 1-year RFS rate of 80.0 % of this study was comparable to those reported in previous registration trials and real-world data. Having ≥ 3 comorbidities was significantly associated with a decrease in RFS (HR: 1.68, 95 % C.I. 1.15–2.44). Conclusion: Older patients had similar benefit of adjuvant immunotherapy compared to older subgroups in previous trials. However, patients with multiple comorbidities were at increased risk of grade ≥ 3 irAEs and had a lower RFS. This should be considered when deciding upon adjuvant treatment.</p

Domain choice in an experimental nested modeling prediction system for South America

The purposes of this paper are to evaluate the new version of the regional model, RegCM3, over South America for two test seasons, and to select a domain for use in an experimental nested prediction system, which incorporates RegCM3 and the European Community-Hamburg (ECHAM) general circulation model (GCM). To evaluate RegCM3, control experiments were completed with RegCM3 driven by both the NCEP/NCAR Reanalysis (NNRP) and ECHAM, using a small control domain (D-CTRL) and integration periods of January–March 1983 (El Niño) and January–March 1985 (La Niña). The new version of the regional model captures the primary circulation and rainfall differences between the two years over tropical and subtropical South America. Both the NNRP-driven and ECHAM-driven RegCM3 improve the simulation of the Atlantic intertropical convergence zone (ITCZ) compared to the GCM. However, there are some simulation errors. Irrespective of the driving fields, weak northeasterlies associated with reduced precipitation are observed over the Amazon. The simulation of the South Atlantic convergence zone is poor due to errors in the boundary condition forcing which appear to be amplified by the regional model. To select a domain for use in an experimental prediction system, sensitivity tests were performed for three domains, each of which includes important regional features and processes of the climate system. The domain sensitivity experiments were designed to determine how domain size and the location of the GCM boundary forcing affect the regional circulation, moisture transport, and rainfall in two years with different large scale conditions. First, the control domain was extended southward to include the exit region of the Andes low level jet (D-LLJ), then eastward to include the South Atlantic subtropical high (D-ATL), and finally westward to include the subsidence region of the South Pacific subtropical high and to permit the regional model more freedom to respond to the increased resolution of the Andes Mountains (D-PAC). In order to quantify differences between the domain experiments, measures of bias, root mean square error, and the spatial correlation pattern were calculated between the model results and the observed data for the seasonal average fields. The results show the GCM driving fields have remarkable control over the RegCM3 simulations. Although no single domain clearly outperforms the others in both seasons, the control domain, D-CTRL, compares most favorably with observations. Over the ITCZ region, the simulations were improved by including a large portion of the South Atlantic subtropical high (D-ATL). The methodology presented here provides a quantitative basis for evaluating domain choice in future studies

Health-related quality-of-life measures for long-term follow-up in children after major trauma

Objective: Our objective was to review measures of health-related quality of life (HRQL) for long-term follow up in children after major trauma and to determine the measures that are suitable for a large age range, reliable and valid, and cover a substantial amount of the domains of functioning using the International Classification of Functioning, Disability, and Health (ICF) of the World Health Organization (WHO). Methods: The Medline and EMBASE databases were searched in all years up to October 2007 for generic HRQL measures suitable for children aged 5-18 years old and validated in English or Dutch. Measures were reviewed with respect to the age range for which the measure was suitable and reliability, validity, and content related to the ICF. Results: The search resulted in 1,235 hits and 21 related articles. Seventy-nine papers met the inclusion criteria, describing in total 14 measures: Child Health and Illness Profile Adolescent and Child Edition (CHIP-AE/CE), Child Health Questionnaire Child and Parent Forms (CHQCF87/PF50/PF28), DISABKIDS, Functional Status II (FS II)(R), Health Utilities Index Mark 2 (HUI 2), KIDSCREEN 52/27, KINDL, Pediatric Quality of Life Inventory (PedsQL), TNO Institute of Prevention and Health and the Leiden University Hospital (TNO-AZL), TNO-AZL Children’s Quality Of Life (TACQOL), and Youth Quality of Life Instrument-Research Version (YQOL-R). Measures that were suitable for a large age range were CHQ-PF50/PF28, DISABKIDS, FS II(R), HUI 2, KIDSCREEN, PedsQL, and TACQOL. All measures had moderate to good psychometric properties, except for CHQ-PF50/PF28, KINDL, and TACQOL, which had either low internal consistency or bad test-retest reliability. The measures that covered more than six chapters of the ICF domains were CHIP-AE/CE, CHQ-CF87/PF50, DISABKIDS, KIDSCREEN-52, PedsQL, and TACQOL. Conclusions: DISABKIDS, KIDSCREEN 52, and Peds-QL are suitable for long-term follow-up measurement of HRQL in children after major trauma. They cover a large age range, have good psychometric properties, and cover the ICF substantially