Assessing microlens quality based on 3D irradiance measurement at the focal spot area

During the fabrication process of microlenses, characterization is essential for two purposes: evaluate the optical quality of the element and provide surface information feedback for process optimization. However, no technique can fulfill these two objectives at the same time. Interferometry is used for quality evaluation and optical profilometry for process optimization. In order to address this problem, we propose to use a high resolution interference microscope to characterize microlenses. The focusing capacity can be directly measured by recording the field near the focal spot at different wavelengths. Information about the microlens surface can also be retrieved. All this is illustrated for the front focus of a fused-silica microlens

Labile plasma iron levels predict survival in patients with lower-risk Myelodysplastic syndromes

Red blood cell transfusions remain one of the cornerstones in supportive care of lower-risk patients with myelodysplastic syndromes. We hypothesized that patients develop oxidant mediated tissue injury through the formation of toxic iron species, caused either by red blood cell transfusions or by ineffective erythropoiesis. We analyzed serum samples from 100 lower-risk patients with myelodysplastic syndromes at six-month intervals for transferrin saturation, hepcidin-25, growth differentiation factor 15, soluble transferrin receptor, non-transferrin bound iron and labile plasma iron in order to evaluate temporal changes in iron metabolism and presence of potentially toxic iron species and their impact on survival. Hepcidin levels were low in 34 patients with ringed sideroblasts compared to 66 patients without. Increases of hepcidin and non-transferrin bound iron levels were visible early in follow-up of all transfusion dependent patient groups. Hepcidin levels significantly decreased over time in transfusion independent patients with ringed sideroblasts. Increased soluble transferrin receptor levels in transfusion-independent patients with ringed sideroblasts confirmed the presence of ineffective erythropoiesis and suppression of hepcidin production in these patients. Detectable labile plasma iron levels in combination with high transferrin saturation levels occurred almost exclusively in patients with ringed sideroblasts and all transfusion dependent patient groups. Detectable labile plasma iron levels in transfusion dependent patients without ringed sideroblasts were associated with decreased survival. IN CONCLUSION: toxic iron species occurred in all transfusion dependent patients and in transfusion independent patients with ringed sideroblasts. Labile plasma iron appeared to be a clinically relevant measure for potential iron toxicity and a prognostic factor for survival in transfusion dependent patients. This trial was registered at www.clinicaltrials.gov as #NCT00600860

Toxic iron species in lower-risk myelodysplastic syndrome patients : course of disease and effects on outcome

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Correction to: Two years later: Is the SARS-CoV-2 pandemic still having an impact on emergency surgery? An international cross-sectional survey among WSES members

Background: The SARS-CoV-2 pandemic is still ongoing and a major challenge for health care services worldwide. In the first WSES COVID-19 emergency surgery survey, a strong negative impact on emergency surgery (ES) had been described already early in the pandemic situation. However, the knowledge is limited about current effects of the pandemic on patient flow through emergency rooms, daily routine and decision making in ES as well as their changes over time during the last two pandemic years. This second WSES COVID-19 emergency surgery survey investigates the impact of the SARS-CoV-2 pandemic on ES during the course of the pandemic. Methods: A web survey had been distributed to medical specialists in ES during a four-week period from January 2022, investigating the impact of the pandemic on patients and septic diseases both requiring ES, structural problems due to the pandemic and time-to-intervention in ES routine. Results: 367 collaborators from 59 countries responded to the survey. The majority indicated that the pandemic still significantly impacts on treatment and outcome of surgical emergency patients (83.1% and 78.5%, respectively). As reasons, the collaborators reported decreased case load in ES (44.7%), but patients presenting with more prolonged and severe diseases, especially concerning perforated appendicitis (62.1%) and diverticulitis (57.5%). Otherwise, approximately 50% of the participants still observe a delay in time-to-intervention in ES compared with the situation before the pandemic. Relevant causes leading to enlarged time-to-intervention in ES during the pandemic are persistent problems with in-hospital logistics, lacks in medical staff as well as operating room and intensive care capacities during the pandemic. This leads not only to the need for triage or transferring of ES patients to other hospitals, reported by 64.0% and 48.8% of the collaborators, respectively, but also to paradigm shifts in treatment modalities to non-operative approaches reported by 67.3% of the participants, especially in uncomplicated appendicitis, cholecystitis and multiple-recurrent diverticulitis. Conclusions: The SARS-CoV-2 pandemic still significantly impacts on care and outcome of patients in ES. Well-known problems with in-hospital logistics are not sufficiently resolved by now; however, medical staff shortages and reduced capacities have been dramatically aggravated over last two pandemic years

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Phase resolved characterization of nanoscale features in optical microstructures

In this study, we apply interferometric microscopy to study the phase, alongside the intensity, of the light field transmitted through a wide variety of samples. Additionally, we conduct those interferometric measurements at different wavelengths within the visible spectrum, probing the spectral evolution of the optical effects that the studied samples create. Using a priori knowledge about the samples, we identify specific features and trends they imprint on the parameters of the transmitted field, thus we optimally analyze the recorded intensity and phase data. We demonstrate that phase maps include useful information that reveal the features of the samples. The wide applicability of the spectrally resolved interference microscopy is the major novelty contributed by the present work. The phase seldom recorded, therefore we first present and explain the tools that we use throughout this work, both in terms of set-up and data post-processing. Next, we show the acquired results, starting from samples with typical dimensions in the few hundreds of microns and concluding with particles of few hundreds of nanometers. More specifically, we study microlenses of high numerical aperture that are difficult to characterize with conventional methods. We propose a novel approach to extract the surface profile of such microlens, providing useful feedback for manufacturing purposes. We do that by using phase measurements at a plane that lies between the surface of the lens and its focal plane. The next sample we study is a phase element, which is naturally easier to discern in the phase domain. We localize specific points in intensity and phase profiles that are correlated to the position of the walls of the actual sample. We also demonstrate the existence of phase singularities in phase measurements that can be proved an invaluable tool in high precision characterization processes. Next, we investigate the photonic nanojet phenomenon, which is the bright spot created on the shadow side of a dielectric sphere. The creation of this bright spot is not achieved through propagation inside the material, like conventional lenses, it is the combination of the light scattered and diffracted by the sphere. Therefore, we study its spectral evolution using intensity measurements and outline the size of the sphere that indicates the crossing from the dominant refractive regime to the diffractive one; combining intensity and phase information, we attempt to identify the size at which the behavior of the dielectric spheres changes again from diffractive to scattering. In the last experiments chapter, we study individual nano-sized particles, which are either simple spheres (dielectric / metallic) or the more complex structures of the core-shell meta-atom. We show that the spectral information of their response in intensity and phase can be used to identify the particle itself (simple dielectric / metal or meta-atom) and assess its responses with the respect to the engineered one (for the meta-atom case). Those examples validate the claimed benefits of the phase exploration. Still, there is ample room for further study; we debate about those prospects in the concluding chapter of this work

Data-Driven Analytics towards Software Sustainability: The Case of Open-Source Multimedia Tools on Cultural Storytelling

The continuous evolution of modern software technologies combined with the deluge of available “ready-to-use” data has triggered revolutionary breakthroughs in several domains, preservation of cultural heritage included. This breakthrough is more than obvious just by considering the numerous multimedia tools and frameworks that actually serve as a means of providing enhanced cultural storytelling experiences (e.g., navigation in historical sites using VR, 3D modeling of artifacts, or even holograms), which are now readily available. In this context and inspired by the vital importance of sustainability as a concept that expresses the need to create the necessary conditions for future generations to use and evolve present artifacts, we target the software engineering domain and propose a systematic way towards measuring the extent to which a software artifact developed and applied in the cultural heritage domain is sustainable. To that end, we present a data-driven methodology that harnesses data residing in online software repositories and involves the analysis of various open-source multimedia tools and frameworks

Public Pensions and Implicit Debt: An Investigation for EU Member States Using Ageing Working Group 2021 Projections

Ιmplicit pension debt is attracting increasing attention worldwide as a driver of fiscal dynamics, operating in parallel to the (explicit) National Debt. A prudent examination of a state’s fiscal prospects should ideally encompass both, with due attention paid to the special features of each kind of debt. The explosion of government deficits as a result of the COVID-19 pandemic only adds to the urgency of understanding the scale and nature of issues around accounting for contingent liabilities. The reports of the EU Ageing working group, produced and published every three years are used to derive estimates of the stock of outstanding implicit pension debt from flows of projected deficits. This can be performed for all European member states. This paper uses the last two rounds of the Ageing Report (2021, 2018) and derives conclusions on the evolution of pension debt and its correlation to the external debt. The paper concludes that producing comparable estimates of IPD should become an important input in EU policy discussion