766 research outputs found

    Convolutional Neural Network for Material Decomposition in Spectral CT Scans

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    Spectral computed tomography acquires energy-resolved data that allows recovery of densities of constituents of an object. This can be achieved by decomposing the measured spectral projection into material projections, and passing these decomposed projections through a tomographic reconstruction algorithm, to get the volumetric mass density of each material. Material decomposition is a nonlinear inverse problem that has been traditionally solved using model-based material decomposition algorithms. However, the forward model is difficult to estimate in real prototypes. Moreover, the traditional regularizers used to stabilized inversions are not fully relevant in the projection domain.In this study, we propose a deep-learning method for material decomposition in the projection domain. We validate our methodology with numerical phantoms of human knees that are created from synchrotron CT scans. We consider four different scans for training, and one for validation. The measurements are corrupted by Poisson noise, assuming that at most 10 5 photons hit the detector. Compared to a regularized Gauss-Newton algorithm, the proposed deep-learning approach provides a compromise between noise and resolution, which reduces the computation time by a factor of 100

    Behavioral assessment of emotional and motivational appraisal during visual processing of emotional scenes depending on spatial frequencies

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    a b s t r a c t Previous studies performed on visual processing of emotional stimuli have revealed preference for a specific type of visual spatial frequencies (high spatial frequency, HSF; low spatial frequency, LSF) according to task demands. The majority of studies used a face and focused on the appraisal of the emotional state of others. The present behavioral study investigates the relative role of spatial frequencies on processing emotional natural scenes during two explicit cognitive appraisal tasks, one emotional, based on the selfemotional experience and one motivational, based on the tendency to action. Our results suggest that HSF information was the most relevant to rapidly identify the self-emotional experience (unpleasant, pleasant, and neutral) while LSF was required to rapidly identify the tendency to action (avoidance, approach, and no action). The tendency to action based on LSF analysis showed a priority for unpleasant stimuli whereas the identification of emotional experience based on HSF analysis showed a priority for pleasant stimuli. The present study confirms the interest of considering both emotional and motivational characteristics of visual stimuli

    Combination of memantine and vitamin D prevents axon degeneration induced by amyloid-beta and glutamate

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    The currently available drugs for treatment of Alzheimer\u27s disease are symptomatic and only temporarily slow down the natural history of the disease process. Recently, its has been proposed that the combination of memantine with vitamin D, a neurosteroid hormone, may prevent amyloid-beta and glutamate neurotoxicity. Here, our purpose was to examine the potential protective effects of memantine and vitamin D against amyloid-beta peptide and glutamate toxicity in cortical neuronal cultures. We provide the first evidence that cortical axons degenerate less after exposure to amyloid-beta peptide or glutamate in microfluidic neuronal cultures enriched with memantine plus vitamin D compared to control medium and cultures enriched with only memantine or only vitamin D. The reported synergistic neuroprotective effect of memantine plus vitamin D -the combination originating an effect stronger than the sum- corroborate previous clinical finding that Alzheimer\u27s disease patients using this drug combination have improved cognition. This finding reinforces the pharmacological potential of a new drug combining memantine plus vitamin D for the treatment or the prevention of Alzheimer\u27s disease

    Composite Outcomes in Observational Studies of Ulcerative Colitis: a Systematic Review and Meta‐Analysis

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    Background: Ulcerative colitis (UC) has been the focus of numerous observational studies over the years and a common strategy employed in their design is the use of composite and aggregate outcomes. Objective: This systematic review and meta-analysis aims to identify composite and aggregate outcomes of observational studies in UC and to evaluate how the number and type of variables included and the length of follow-up affect the frequency of patients that achieve these outcomes. Methods: A systematic literature search was carried out using MEDLINE [via PubMed], Scopus, and Web of Science online databases. Observational studies that included UC patients and reported composite or aggregate outcomes were identified. A set of variables considered to be representative of progressive or disabling UC was defined, the proportion of patients attaining the outcomes was determined and a random-effects meta-analysis was performed by dividing the identified studies into subgroups according to different criteria of interest. Results: A total of 10,264 records were identified in the systematic search, of which 33 were retained for qualitative analysis and 20 were included in the meta-analysis. The mean frequency for composite outcomes was 0.363 [95% confidence interval (CI) 0.323-0.403]. The frequency of composite outcome for the subgroup of studies that included the variable "Biologics" was significantly higher than for those in which this variable was not reported [0.410; 95% CI 0.364-0.457 versus 0.298; 95% CI 0.232-0.364; p = 0.006]. Composite outcomes were also more frequent as the follow-up duration increased. Conclusion: The frequency of composite outcomes in observational studies of UC is dependent on the specific identity of the variables being reported. Moreover, longer follow-up periods are associated with higher frequencies of composite outcomes. The evidence provided here is useful for the design of future observational studies of UC that aim to maximize the frequency of patients that achieve composite outcomes.info:eu-repo/semantics/publishedVersio

    Modeling the influence of Twitter in reducing and increasing the spread of influenza epidemics

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    In this paper we present compartmentalized neuron arraying (CNA) microfluidic circuits for the preparation of neuronal networks using minimal cellular inputs (10–100-fold less than existing systems). The approach combines the benefits of microfluidics for precision single cell handling with biomaterial patterning for the long term maintenance of neuronal arrangements. A differential flow principle was used for cell metering and loading along linear arrays. An innovative water masking technique was developed for the inclusion of aligned biomaterial patterns within the microfluidic environment. For patterning primary neurons the technique involved the use of meniscus-pinning micropillars to align a water mask for plasma stencilling a poly-amine coating. The approach was extended for patterning the human SH-SY5Y neuroblastoma cell line using a poly(ethylene glycol) (PEG) back-fill and for dopaminergic LUHMES neuronal precursors by the further addition of a fibronectin coating. The patterning efficiency Epatt was >75% during lengthy in chip culture, with ~85% of the outgrowth channels occupied by neurites. Neurons were also cultured in next generation circuits which enable neurite guidance into all outgrowth channels for the formation of extensive inter-compartment networks. Fluidic isolation protocols were developed for the rapid and sustained treatment of the different cellular and sub-cellular compartments. In summary, this research demonstrates widely applicable microfluidic methods for the construction of compartmentalized brain models with single cell precision. These minimalistic ex vivo tissue constructs pave the way for high throughput experimentation to gain deeper insights into pathological processes such as Alzheimer and Parkinson Diseases, as well as neuronal development and function in health

    Extra-intestinal malignancies in inflammatory bowel disease: Results of the 3rd ECCO Pathogenesis Scientific Workshop (III)

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    AbstractThe incidence of lymphoproliferative disorders (LD) is increasing in developed countries. Patients with inflammatory bowel disease (IBD) exposed to thiopurines are at additional risk of three specific forms of LD: Epstein-Barr-Virus-related post-transplant like LD, hepato-splenic T-cell lymphoma and post-mononucleosis lymphoproliferation. The risk of the two latter forms of LD can be reduced when considering specific immunosuppressive strategies in young males. It is still unclear whether the risk of uterine cervix abnormalities is increased in IBD women, irrespective of the use of immunosuppressants. Given the excess risk demonstrated in various other contexts of immunosuppression, it is currently recommended that all women with IBD, particularly those receiving immunosuppressants, strictly adhere to a screening program of cervical surveillance and undergo vaccination against HPV, when appropriate. Patients with IBD receiving immunosuppressants are at increased risk of skin cancers. The risk of non-melanoma skin cancer is notably increased in patients receiving thiopurines. Recent data suggest that the risk of melanoma is mildly increased in patients exposed to anti-TNF therapy. All IBD patients should adhere to a program of sun protection and dermatological surveillance, whose details should take into account the other non-IBD-related risk factors

    High prevalence of overweight and obesity in adults with Crohn's disease: associations with disease and lifestyle factors.

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    peer-reviewedObesity and overweight are major public health issues. Although traditionally associated with weight loss, there is now evidence that increasing Body Mass Index (BMI) and overweight are emerging features of Crohn's disease (CD) and may be associated with more severe disease course. The aim of the study was to determine the prevalence of overweight and obesity in patients with CD compared with matched healthy controls and to identify disease-specific and generic factors associated with current BMI in this group.PUBLISHEDpeer-reviewe

    Innovative approaches to biologic development on the trail of CT-P13: biosimilars, value-added medicines, and biobetters.

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    The biosimilar concept is now well established. Clinical data accumulated pre- and post-approval have supported biosimilar uptake, in turn stimulating competition in the biologics market and increasing patient access to biologics. Following technological advances, other innovative biologics, such as "biobetters" or "value-added medicines," are now reaching the market. These innovative biologics differ from the reference product by offering additional clinical or non-clinical benefits. We discuss these innovative biologics with reference to CT-P13, initially available as an intravenous (IV) biosimilar of reference infliximab. A subcutaneous (SC) formulation, CT-P13 SC, has now been developed. Relative to CT-P13 IV, CT-P13 SC offers clinical benefits in terms of pharmacokinetics, with comparable efficacy, safety, and immunogenicity, as well as increased convenience for patients and reduced demands on healthcare system resources. As was once the case for biosimilars, nomenclature and regulatory pathways for innovative biologics require clarification to support their uptake and ultimately benefit patients

    I-CARE, a European Prospective Cohort Study Assessing Safety and Effectiveness of Biologics in Inflammatory Bowel Disease

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    Background and aims: There is a need to evaluate the benefit-risk ratio of current therapies in inflammatory bowel disease (IBD) patients to provide the best quality of care. The primary objective of I-CARE (IBD Cancer and serious infections in Europe) was to assess prospectively safety concerns in IBD, with specific focus on the risk of cancer/lymphoma and serious infections in patients treated with anti-tumor necrosis factor and other biologic monotherapy as well as in combination with immunomodulators.. Methods: I-CARE was designed as a European prospective longitudinal observational multicenter cohort study to include patients with a diagnosis of Crohn's disease, ulcerative colitis, or IBD unclassified established at least 3 months prior to enrollment. Results: A total of 10,206 patients were enrolled between March 2016 and April 2019, including 6169 (60.4%) patients with Crohn's disease, 3853 (37.8%) with ulcerative colitis, and 184 (1.8%) with a diagnosis of IBD unclassified. Thirty-two percent of patients were receiving azathioprine/thiopurines, 4.6% 6-mercaptopurine, and 3.2% methotrexate at study entry. At inclusion, 47.3% of patients were treated with an anti-tumor necrosis factor agent, 8.8% with vedolizumab, and 3.4% with ustekinumab. Roughly one-quarter of patients (26.8%) underwent prior IBD-related surgery. Sixty-six percent of patients had been previously treated with systemic steroids. Three percent of patients had a medical history of cancer prior to inclusion and 1.1% had a history of colonic, esophageal, or uterine cervix high-grade dysplasia.. Conclusions: I-CARE is an ongoing investigator-initiated observational European prospective cohort study that will provide unique information on the long-term benefits and risks of biological therapies in IBD patients

    Reorganisation of faecal microbiota transplant services during the COVID-19 pandemic

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    The COVID-19 pandemic has led to an exponential increase in SARS-CoV-2 infections and associated deaths, and represents a significant challenge to healthcare professionals and facilities. Individual countries have taken several prevention and containment actions to control the spread of infection, including measures to guarantee safety of both healthcare professionals and patients who are at increased risk of infection from COVID-19. Faecal microbiota transplantation (FMT) has a well-established role in the treatment of Clostridioides difficile infection. In the time of the pandemic, FMT centres and stool banks are required to adopt a workflow that continues to ensure reliable patient access to FMT while maintaining safety and quality of procedures. In this position paper, based on the best available evidence, worldwide FMT experts provide guidance on issues relating to the impact of COVID-19 on FMT, including patient selection, donor recruitment and selection, stool manufacturing, FMT procedures, patient follow-up and research activities.Peer reviewe
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