1,703 research outputs found

    Online geometry assurance in individualized production by feedback control and model calibration of digital twins

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    In this paper, we consider online calibration of a Digital Twin and its use for control and optimization in the assembly process of sheet metal parts. This calibration is done based on a feedback signal received by calculating the quality of the simulated assemblies as compared to the prediction made by the Digital Twin. We develop a Kalman filter-based approach for online calibration of the Digital Twin, which in turn is used by a one-step look-ahead optimizer to define an online control scheme. This control scheme balances directly predicted quality gains against reduced uncertainty whose purpose is to enable long-term quality gains. The usage of a calibrated model in a one-step look-ahead optimizer as a controller allows to incorporate the benefits of the usage of Digital Twins for individualized control, where the control parameters of a production cell are optimized in a Digital Twin based on measured properties of the production inputs, over nominal control, where control parameters are set with respect to some reference production inputs, in an approach which is able to use measured final production quality for feedback control. The proposed approach is evaluated by computer simulations of two industrial product assembly use cases. In the first case, it demonstrates significant gains in quality of the produced assemblies, while in the second case it shows negligible to small improvements. The second case is, however, rather insensitive to miscalibration, which enables only small gains

    The NHS breast cancer screening programme

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    Technologies for Interoperable Internet of Medical Things Platforms to Manage Medical Emergencies in Home and Prehospital Care: Protocol for a Scoping Review

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    Background: Population growth and aging have highlighted the need for more effective home and prehospital care. Interconnected medical devices and applications, which comprise an infrastructure referred to as the Internet of Medical Things (IoMT), have enabled remote patient monitoring and can be important tools to cope with these demographic changes. However, developing IoMT platforms requires profound knowledge of clinical needs and challenges related to interoperability and how these can be managed with suitable technologies. Objective: The purpose of this scoping review is to summarize the best practices and technologies to overcome interoperability concerns in IoMT platform development for medical emergencies in home and prehospital care. Methods: This scoping review will be conducted in accordance with Arksey and O\u27Malley\u27s 5-stage framework and adhere to the PRISMA-P (Preferred Reporting Items for Systematic Reviews and Meta-analyses Protocols) guidelines. Only peer-reviewed articles published in English will be considered. The databases/web search engines that will be used are IEEE Xplore, PubMed, Scopus, Google Scholar, National Center for Biotechnology Information, SAGE Journals, and ScienceDirect. The search process for relevant literature will be divided into 4 different steps. This will ensure that a suitable approach is followed in terms of search terms, limitations, and eligibility criteria. Relevant articles that meet the inclusion criteria will be screened in 2 stages: abstract and title screening and full-text screening. To reduce selection bias, the screening process will be performed by 2 reviewers. Results: The results of the preliminary search indicate that there is sufficient literature to form a good foundation for the scoping review. The search was performed in April 2022, and a total of 4579 articles were found. The main clinical focus is the prevention and management of falls, but other medical emergencies, such as heart disease and stroke, are also considered. Preliminary results show that little attention has been given to real-time IoMT platforms that can be deployed in real-world care settings. The final results are expected to be presented in a scoping review in 2023 and will be disseminated through scientific conference presentations, oral presentations, and publication in a peer-reviewed journal. Conclusions: This scoping review will provide insights and recommendations regarding how interoperable real-time IoMT platforms can be developed to handle medical emergencies in home and prehospital care. The findings of this research could be used by researchers, clinicians, and implementation teams to facilitate future development and interdisciplinary discussions

    The native architecture of a photosynthetic membrane

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    In photosynthesis, the harvesting of solar energy and its subsequent conversion into a stable charge separation are dependent upon an interconnected macromolecular network of membrane-associated chlorophyll–protein complexes. Although the detailed structure of each complex has been determined, the size and organization of this network are unknown. Here we show the use of atomic force microscopy to directly reveal a native bacterial photosynthetic membrane. This first view of any multi-component membrane shows the relative positions and associations of the photosynthetic complexes and reveals crucial new features of the organization of the network: we found that the membrane is divided into specialized domains each with a different network organization and in which one type of complex predominates. Two types of organization were found for the peripheral light-harvesting LH2 complex. In the first, groups of 10–20 molecules of LH2 form light-capture domains that interconnect linear arrays of dimers of core reaction centre (RC)–light-harvesting 1 (RC–LH1–PufX) complexes; in the second they were found outside these arrays in larger clusters. The LH1 complex is ideally positioned to function as an energy collection hub, temporarily storing it before transfer to the RC where photochemistry occurs: the elegant economy of the photosynthetic membrane is demonstrated by the close packing of these linear arrays, which are often only separated by narrow 'energy conduits' of LH2 just two or three complexes wide

    Determinants of the number of mammography units in 31 countries with significant mammography screening

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    In the 2000s, most of the female population of industrialised countries had access to mammography breast cancer screening, but with variable modalities among the countries. We assessed the number of mammography units (MUs) in 31 European, North American and Asian countries where significant mammography activity has existed for over 10 years, collecting data on the number of such units and of radiologists by contacting institutions in each country likely to provide the relevant information. Around 2004, there were 32 324 MU in 31 countries, the number per million women ranging from less than 25 in Turkey, Denmark, the Netherlands, the United Kingdom, Norway, Poland and Hungary to more than 80 in Cyprus, Italy, France, the United States and Austria. In a multivariate analysis, the number of MUs was positively associated with the number of radiologists (P=0.0081), the number of women (P=0.0023) and somewhat with the country surface area (P=0.077). There is considerable variation in the density of MU across countries and the number of MUs in service are often well above what would be necessary according to local screening recommendations. High number of MUs in some countries may have undesirable consequences, such as unnecessarily high screening frequency and decreased age at which screening is started

    Comprehensive evaluation of Toxoplasma gondii VEG and Neospora caninum LIV genomes with tachyzoite stage transcriptome and proteome defines novel transcript features.

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    Toxoplasma gondii is an important protozoan parasite that infects all warm-blooded animals and causes opportunistic infections in immuno-compromised humans. Its closest relative, Neospora caninum, is an important veterinary pathogen that causes spontaneous abortion in livestock. Comparative genomics of these two closely related coccidians has been of particular interest to identify genes that contribute to varied host cell specificity and disease. Here, we describe a manual evaluation of these genomes based on strand-specific RNA sequencing and shotgun proteomics from the invasive tachyzoite stages of these two parasites. We have corrected predicted structures of over one third of the previously annotated gene models and have annotated untranslated regions (UTRs) in over half of the predicted protein-coding genes. We observe distinctly long UTRs in both the organisms, almost four times longer than other model eukaryotes. We have also identified a putative set of cis-natural antisense transcripts (cis-NATs) and long intergenic non-coding RNAs (lincRNAs). We have significantly improved the annotation quality in these genomes that would serve as a manually curated dataset for Toxoplasma and Neospora research communities

    Regular Exercise or Changing Diet Does Not Influence Aortic Valve Disease Progression in LDLR Deficient Mice

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    BACKGROUND: The development and progression of calcific aortic valve disease (CAVD) shares a number of similarities with atherosclerosis. Recently we could demonstrate that regular exercise training (ET) as primary prevention prevents aortic valve disease in LDL-receptor deficient (LDLR(-/-)) mice. We aimed to investigate the impact of exercise training on the progression of CAVD in LDLR(-/-) mice in the setting of secondary prevention METHODS AND RESULTS: Sixty-four LDLR(-/-) mice were fed with high cholesterol diet to induce aortic valve sclerosis. Thereafter the animals were divided into 3 groups: group 1 continuing on high cholesterol diet, group 2 continuing with cholesterol diet plus 1 h ET per day, group 3 continuing with normal mouse chow. After another 16 weeks the animal were sacrificed. Histological analysis of the aortic valve thickness demonstrated no significant difference between the three groups (control 98.3±4.5 µm, ET 88.2±6.6 µm, change in diet 87.5±4.0). Immunohistochemical staining for endothelial cells revealed a disrupted endothelial cell layer to the same extend in all groups. Furthermore no difference between the groups was evident with respect to the expression of inflammatory, fibroblastic and osteoblastic markers. CONCLUSION: Based on the present study we have to conclude that once the development of a CAVD is initiated, exercise training or a change in diet does not have the potential to attenuate the progress of the CAVD

    Cerebral involvement in a patient with Goodpasture's disease due to shortened induction therapy: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Goodpasture's disease is a rare immunological disease with formation of pathognomonic antibodies against renal and pulmonary basement membranes. Cerebral involvement has been reported in several cases in the literature, yet the pathogenetic mechanism is not entirely clear.</p> <p>Case presentation</p> <p>A 21-year-old Caucasian man with Goodpasture's disease and end-stage renal disease presented with two generalized seizures after a period of mild cognitive disturbance. Blood pressure and routine laboratory tests did not exceed the patient's usual values, and examination of cerebrospinal fluid was unremarkable. Cerebral magnetic resonance imaging (MRI) revealed multiple cortical and subcortical lesions on fluid-attenuated inversion recovery sequences. Since antiglomerular basement membrane antibodies were found to be positive with high titers, plasmapheresis was started. In addition, cyclophosphamide pulse therapy was given on day 13. Encephalopathy and MRI lesions disappeared during this therapy, and antiglomerular basement membrane antibodies were significantly reduced. Previous immunosuppressive therapy was performed without corticosteroids and terminated early after 3 months.</p> <p>The differential diagnostic considerations were cerebral vasculitis and posterior reversible encephalopathy syndrome. Vasculitis could be seen as an extrarenal manifestation of the underlying disease. Posterior reversible encephalopathy syndrome, on the other hand, can be triggered by immunosuppressive therapy and may appear without a hypertensive crisis.</p> <p>Conclusion</p> <p>A combination of central nervous system symptoms with a positive antiglomerular basement membrane test in a patient with Goodpasture's disease should immediately be treated as an acute exacerbation of the disease with likely cross-reactivity of antibodies with the choroid plexus. In our patient, a discontinuous strategy of immunosuppressive therapy may have favored recurrence of Goodpasture's disease.</p
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