431 research outputs found

    Reduced bending and scattering losses in new optical `double-ridge' waveguide

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    A new type of waveguide is proposed combining a low and a high ridge. Experiments at lambda =632.8 nm show an excess loss of 0.6 dB for a 90 degrees bend with R=50 mu m in SiO/sub 2/ cladded Al/sub 2/O/sub 3/, and showing reduced scattering losses compared with a conventional ridge waveguid

    Economic evaluations in medical technological innovations a mapping review of methodologies

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    RATIONALE: Economic evaluations play an important role in the development and implementation of healthcare innovations. For pharmaceutical products, the methodologies used are laid down in guidelines, whereas for medical technologies the guidelines are not as strenuous. The aim of this review was therefore to analyze what types of methodologies are used in economic evaluations of medical technologies. METHODS: We performed a mapping review to identify economic evaluations for medical technologies. We decided to limit our search to one year (2022) and included cost utility and cost effectiveness analyses in which health technologies were evaluated. For each included study we identified the main methodological characteristics. RESULTS: A total of 364 papers were included in the analysis, 268 (74%) contained cost-utility analyses and 91 (25%) cost-effectiveness analyses. A model was used in 236 (64%) analyses, 117 analyses were trial based evaluations. Probabilistic sensitivity analyses and/or bootstrapping was performed in 266 (73%) analyses. Deterministic sensitivity analyses were used in 306 (84%). Time horizon and perspective were underreported in 15-25% of the included studies. CONCLUSIONS: This review shows the wide range of methodologies used in economic evaluations as well as the extent and rigor in which these methodologies are used. Many of the included papers did no use or did not sufficiently report the use of appropriate standard methods. This may lead to research waste, a delay in successful implementation of valuable innovations and in the end may delay improvement patient outcomes

    Development and validation of PRE-DELIRIC (PREdiction of DELIRium in ICu patients) delirium prediction model for intensive care patients: observational multicentre study

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    Objectives To develop and validate a delirium prediction model for adult intensive care patients and determine its additional value compared with prediction by caregivers

    Predicting success of vagus nerve stimulation (VNS) from interictal EEG

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    AbstractPurposeVagus nerve stimulation (VNS) has shown to be an effective treatment for drug resistant epilepsy in numerous patients, however, not in all. It is still not possible to predict which patients will profit from VNS. In this pilot study, we explore predictive interictal EEG features for seizure reduction after VNS.Methods19 Patients with medically refractory epilepsy and an implanted VNS system were included. Interictal EEG registrations, recorded before implantation, were retrospectively analysed. A quantative symmetry measure, the pair wise derived brain symmetry index (pdBSI), was tested to predict VNS outcome. Reduction in seizure frequency was used to define the responders.Results10 Patients did respond to VNS, of whom 7 patients had a seizure reduction of at least 50% in a follow-up period of 2 years. On average, we find higher pdBSI values for delta, theta, alpha and beta bands for non-responders than for responders. The average pdBSI of the theta and alpha bands could significantly discriminate between responders and non-responders.ConclusionIn this study, quantifying EEG symmetry using the pdBSI shows promising results in predicting the reduction of seizure frequency after VNS treatment

    'Nurses' self-management support to hospitalised patients: a scoping review

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    Aims and Objectives: To review the current literature to map and explore the interventions that have been considered or used by nurses to support adult patients' self-management during hospitalisation. Background: Nurses can play an important role in supporting patients' self-management. Currently, however, it is unclear how nurses perform this task during a patient's stay in hospital. Traditionally, nurses take the primary role in managing patients' care during hospitalisation. Ideally, patients should have the opportunity to continue applying strategies to manage their health conditions as much as possible while in the hospital. This can increase patients' self-efficacy and decrease unnecessary readmissions. Design: Scoping review informed by the Joanna Briggs Institute methodology. Methods: A database search was undertaken using Pubmed, CINAHL, Psycinfo, Cochrane, Embase and grey literature sources. Data from the included studies were mapped and summarised in a narrative summary. To synthesise the information that was given about each intervention, we conducted a qualitative inductive content analysis. Results are reported in accordance with the guidelines for reporting Items for systematic review and meta-analyses extension for scoping review (PRISMA-ScR) (Supplementary File 1). Results: 83 documents were included in this review. Based on the information about the interventions, three themes were identified: 'self-management support activities', 'focus of self-management support' and the 'intervention procedure'. Five self-management support activities can be distinguished: 'giving education', 'counselling and coaching', 'enhancing responsibility', 'engaging family-caregivers' and 'supporting transition from hospital to home'. The interventions focused on improving disease-related knowledge and on strengthening several self-management skills. Information about the procedure, development and the theoretical underpinning of the intervention was often limited. Conclusions: Most activities within the nursing interventions to support adult patients' self-management during hospitalisation are the part of regular nursing care. However, the transfer of responsibility for care task to the patient is relatively new. Further research could focus on developing interventions addressing all aspects of self-management and that are embedded in the patient's care pathway across settings.Pathophysiology, epidemiology and therapy of agein

    Experience-based behavioral and chemosensory changes in the generalist insect herbivore Helicoverpa armigera exposed to two deterrent plant chemicals

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    Behavioral and electrophysiological responses of larvae of the polyphagous moth species Helicoverpa armigera to two plant-derived allelochemicals were studied, both in larvae that had been reared on a diet devoid of these compounds and in larvae previously exposed to these compounds. In dual-choice cotton leaf disk and pepper fruit disk arena assays, caterpillars reared on a normal artificial diet were strongly deterred by strychnine and strophanthin-K. However, caterpillars reared on an artificial diet containing strychnine were insensitive to strychnine and strophanthin-K. Similarly, caterpillars reared on an artificial diet containing strophanthin-K were also desensitized to both deterrent chemicals. Electrophysiological tests revealed that the deterrent-sensitive neurons in taste sensilla on the maxillae of caterpillars reared on each deterrent-containing diet displayed reduced sensitivity to the two chemicals compared with the caterpillars reared on normal diets. We conclude that the experience-dependent behavioral plasticity was partly based on the reduced sensitivity of taste receptor neurons and that the desensitization of taste receptor neurons contributed to the cross-habituation to the two chemicals

    Interpretation of continuously measured vital signs data of COVID-19 patients by nurses and physicians at the general ward: A mixed methods study

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    Background Continuous monitoring of vital signs is introduced at general hospital wards to detect patient deterioration. Interpretation and response currently rely on experience and expert opinion. This study aims to determine whether consensus exist among hospital professionals regarding the interpretation of vital signs of COVID-19 patients. In addition, we assessed the ability to recognise respiratory insufficiency and evaluated the interpretation process. Methods We performed a mixed methods study including 24 hospital professionals (6 nurses, 6 junior physicians, 6 internal medicine specialists, 6 ICU nurses). Each participant was presented with 20 cases of COVID-19 patients, including 4 or 8 hours of continuously measured vital signs data. Participants estimated the patient's situation ('improving', 'stable', or 'deteriorating') and the possibility of developing respiratory insufficiency. Subsequently, a semi-structured interview was held focussing on the interpretation process. Consensus was assessed using Krippendorff's alpha. For the estimation of respiratory insufficiency, we calculated the mean positive/negative predictive value. Interviews were analysed using inductive thematic analysis. Results We found no consensus regarding the patient's situation (α 0.41, 95%CI 0.29-0.52). The mean positive predictive value for respiratory insufficiency was high (0.91, 95%CI 0.86- 0.97), but the negative predictive value was 0.66 (95%CI 0.44-0.88). In the interviews, two themes regarding the interpretation process emerged. "Interpretation of deviations"included the strategies participants use to determine stability, focused on finding deviations in data. "Inability to see the patient"entailed the need of hospital professionals to perform a patient evaluation when estimating a patient's situation. Conclusion The interpretation of continuously measured vital signs by hospital professionals, and recognition of respiratory insufficiency using these data, is variable, which might be the result of different interpretation strategies, uncertainty regarding deviations, and not being able to see the patient. Protocols and training could help to uniform interpretation, but decision support systems might be necessary to find signs of deterioration that might otherwise go unnoticed

    Olfactory receptors on the maxillary palps of small ermine moth larvae: evolutionary history of benzaldehyde sensitivity

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    In lepidopterous larvae the maxillary palps contain a large portion of the sensory equipment of the insect. Yet, knowledge about the sensitivity of these cells is limited. In this paper a morphological, behavioral, and electrophysiological investigation of the maxillary palps of Yponomeuta cagnagellus (Lepidoptera: Yponomeutidae) is presented. In addition to thermoreceptors, CO2 receptors, and gustatory receptors, evidence is reported for the existence of two groups of receptor cells sensitive to plant volatiles. Cells that are mainly sensitive to (E)-2-hexenal and hexanal or to (Z)-3-hexen-1-ol and 1-hexanol were found. Interestingly, a high sensitivity for benzaldehyde was also found. This compound is not known to be present in Euonymus europaeus, the host plant of the monophagous Yponomeuta cagnagellus, but it is a prominent compound in Rosaceae, the presumed hosts of the ancestors of Y. cagnagellus. To elucidate the evolutionary history of this sensitivity, and its possible role in host shifts, feeding responses of three Yponomeuta species to benzaldehyde were investigated. The results confirm the hypothesis that the sensitivity to benzaldehyde evolved during the ancestral shift from Celastraceae to Rosaceae and can be considered an evolutionary relict, retained in the recently backshifted Celastraceae-specialist Y. cagnagellus
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