222 research outputs found

    Vacuum-ultraviolet frequency-modulation spectroscopy

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    Frequency-modulation (FM) spectroscopy has been extended to the vacuum-ultraviolet (VUV) range of the electromagnetic spectrum. Coherent VUV laser radiation is produced by resonance-enhanced sum-frequency mixing (νVUV=2νUV+ν2\nu_{\mathrm{VUV}}=2\nu_{\mathrm{UV}}+\nu_2) in Kr and Xe using two near-Fourier-transform-limited laser pulses of frequencies νUV\nu_{\mathrm{UV}} and ν2\nu_2. Sidebands generated in the output of the second laser (ν2\nu_2) using an electro-optical modulator operating at the frequency νmod\nu_{\mathrm{mod}} are directly transfered to the VUV and used to record FM spectra. Demodulation is demonstrated both at νmod\nu_{\mathrm{mod}} and 2νmod2\nu_{\mathrm{mod}}. The main advantages of the method are that its sensitivity is not reduced by pulse-to-pulse fluctuations of the VUV laser intensity, compared to VUV absorption spectroscopy is its background-free nature, the fact that its implementation using table-top laser equipment is straightforward and that it can be used to record VUV absorption spectra of cold samples in skimmed supersonic beams simultaneously with laser-induced-fluorescence and photoionization spectra. To illustrate these advantages we present VUV FM spectra of Ar, Kr, and N2_2 in selected regions between 105000cm1^{-1} and 122000cm1^{-1}.Comment: 23 pages, 10 figure

    Dissociation energy of the hydrogen molecule at 109^{-9} accuracy

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    The ionization energy of ortho-H2_2 has been determined to be EIo(H2)/(hc)=124357.238062(25)E^\mathrm{o}_\mathrm{I}(\mathrm{H}_2)/(hc)=124\,357.238\,062(25) cm1^{-1} from measurements of the GK(1,1)--X(0,1) interval by Doppler-free two-photon spectroscopy using a narrow band 179-nm laser source and the ionization energy of the GK(1,1) state by continuous-wave near-infrared laser spectroscopy. EIoE^\mathrm{o}_\mathrm{I}(H2_2) was used to derive the dissociation energy of H2_2, D0N=1D^{N=1}_{0}(H2_2), at 35999.582894(25)35\,999.582\,894(25) cm1^{-1} with a precision that is more than one order of magnitude better than all previous results. The new result challenges calculations of this quantity and represents a benchmark value for future relativistic and QED calculations of molecular energies.Comment: 6 pages, 5 figure

    Severe and ChRonic Atopic dermatitis Treatment CoHort (SCRATCH):A Danish Real-world Evidence Atopic Dermatitis Treatment Registry

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    Data from real-world use of new systemic treatments in atopic dermatitis (AD) is important for assessing safety and efficacy. The aim of this study is to describe the baseline characteristics of adult patients with moderate-to-severe AD enrolled in the Danish nationwide Severe and ChRonic Atopic dermatitis Treatment CoHort (SCRATCH) database, between October 2017 and August 2021. A total of 282 adult patients were included. Most (62%) were men, the median age at baseline was 43 years (interquartile range (IQR) 29–54 years), and median age at onset of AD was 1 year (IQR 0–6 years). The median Eczema Area and Severity Index at treatment initiation was 19.1 (IQR 11.9–25.7); median Patient Oriented Eczema Measure 21.0 (IQR 16.0–25.0); median Dermatology Life Quality Index 13.0 (IQR 7.0–19.0); and median itch and sleep numerical rating scale scores 8.0 (IQR 6.0–9.0) and 6.0 (IQR 4.0–8.0). Differences were found between the sexes. This registry will provide a source for future efficacy and safety studies

    Chronic hand eczema in Europe:Patient experiences and perspectives (CHEPEP) in qualitative interviews

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    Background: Chronic hand eczema (CHE) is a very common skin disease among the European population. It causes itch and pain and, in more severe cases, seriously impairs hand functioning at work and in private life. Objectives: To explore perspectives of people with lived experience on CHE-related problems, wishes and goals. Methods: Following a qualitative approach, we conducted topic-guided interviews in five European countries and applied template analysis to identify recurrent themes among patients with CHE. Results: We interviewed 60 patients in seven outpatient dermatological and occupational medicine clinics in Croatia, Denmark, Germany, the Netherlands and Spain. Five main themes were identified: (1) knowledge about the disease and its course, (2) preventive behaviour, (3) hand eczema therapy, (4) impact on everyday life and (5) attitudes towards CHE and healthcare. Participants did not feel well informed about CHE, especially about causes, triggers and treatment options. Preventive measures were experienced as more or less effective but also cumbersome. Experiences with therapy were diverse. Treatment satisfaction depended on the results and on the perceived support from the treatment teams. Participants found it important to be taken seriously, to receive practical advice, to try out additional treatments or examinations, find new hope and have occupational perspectives. They wished that others could better understand the physical and emotional burden of CHE. Patient support groups were not mentioned. Participants found it important to learn to take care of themselves and accept life with CHE. Conclusions: Due to its annoying symptoms, high visibility and impaired functioning at work and in private life, CHE has a high emotional and social impact. Some people may require support to learn coping with CHE and its prevention. Patients wish for information about causes and triggers. They value physicians who listen to them and keep looking for solutions.</p

    The relevance of model-driven engineering thirty years from now

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    International audienceAlthough model-driven engineering (MDE) is now an established approach for developing complex software systems, it has not been universally adopted by the software industry. In order to better understand the reasons for this, as well as to identify future opportunities for MDE, we carried out a week-long design thinking experiment with 15 MDE experts. Participants were facilitated to identify the biggest problems with current MDE technologies, to identify grand challenges for society in the near future, and to identify ways that MDE could help to address these challenges. The outcome is a reflection of the current strengths of MDE, an outlook of the most pressing challenges for society at large over the next three decades, and an analysis of key future MDE research opportunities

    Loitering with intent: dealing with human-intensive systems

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    This paper discusses the professional roles of information systems analysts and users, focusing on a perspective of human intensive, rather than software intensive information systems. The concept of ‘meaningful use’ is discussed in re-lation to measures of success/failure in IS development. The authors consider how a number of different aspects of reductionism may distort analyses, so that processes of inquiry cannot support organizational actors to explore and shape their requirements in relation to meaningful use. Approaches which attempt to simplify complex problem spaces, to render them more susceptible to ‘solution’ are problematized. Alternative perspectives which attempt a systematic, holistic complexification, by supporting contextual dependencies to emerge, are advocated as a way forward

    Evidence-Based Management of Hand Eczema

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    Hand eczema is a common skin disease with a wide variation in morphology and a complex etiology based on endogenous and exogenous factors.The diagnosis of hand eczema is based on patient history, exposure assessment, physical examination, and the results of patch testing. Management of hand eczema starts with education of the patient on the etiology of the disease, and the needed changes in behavior regarding skin care and preventive measures, and avoidance of relevant exposure factors. In many cases, medical treatment is needed for successful management of the disease; use of medication can only be successful with proper education and avoidance of relevant exposure

    An Empirical Investigation to Understand the Difficulties and Challenges of Software Modellers When Using Modelling Tools

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    Software modelling is a challenging and error-prone task. Existing Model-Driven Engineering (MDE) tools provide modellers with little aid, partly because tool providers have not investigated users' difficulties through empirical investigations such as field studies. This paper presents the results of a two-phase user study to identify the most prominent difficulties that users might face when developing UML Class and State-Machine diagrams using UML modelling tools. In the first phase, we identified the preliminary modelling challenges by analysing 30 Class and State-Machine models that were previously developed by students as a course assignment. The result of the first phase helped us design the second phase of our user study where we empirically investigated different aspects of using modelling tools: the tools' effectiveness, users' efficiency, users' satisfaction, the gap between users' expectation and experience, and users' cognitive difficulties. Our results suggest that users' greatest difficulties are in (1) remembering contextual information and (2) identifying and fixing errors and inconsistencies.NSERC CREATE, 465463-2015 || NSERC Discovery Grant, 155243-1

    Cognition and resective surgery for diffuse infiltrative glioma: an overview

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    Compared to classical oncological outcome measures such as time to progression and survival, the importance of cognitive functioning in patients with diffuse infiltrative brain tumors has only recently been recognized. Apart from the relatively low incidence and the invariably fatal outcome of gliomas, the general assumption that cognitive assessment is time-consuming and burdensome contributes to this notion. Our understanding of the effects of brain surgery on cognition, for instance, is largely based on studies in surgical patients with refractory epilepsy, with only a limited number of studies in surgical patients with gliomas. The impact of other factors affecting cognition in glioma patients such as direct tumor effects, radiotherapy and chemotherapy, and medical treatment, including anti-epileptic drugs and steroids, have been studied more extensively. The purpose of this paper is to provide an overview of cognition in patients with diffuse infiltrative gliomas and the impact of resective surgery as well as other tumor and treatment-related factors
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