71 research outputs found

    Multiple superconducting ring ratchets for ultrasensitive detection of non-equilibrium noises

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    Magnetic quantum periodicity in the dc voltage is observed when asymmetric rings are switched between superconducting and normal state by a noise or ac current. This quantum effect is used for detection of a non-equilibrium noise with the help of a system of 667 asymmetric aluminum rings of 1 μm1 \ \mu m in diameter connected in series. Any noise down to the equilibrium one can be detected with the help of such system with enough great number of asymmetric rings.Comment: 6 pages, 6 figure

    A systematic review and meta-analysis of outcomes after elective surgery for ulcerative colitis.

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    AIM: Approximately 20%-30% of patients with ulcerative colitis (UC) will undergo surgery during their disease course, the vast majority being elective due to chronic refractory disease. The risks of elective surgery are reported variably. The aim of this systematic review and meta-analysis is to summarize the outcomes after elective surgery for UC. METHODS: A systematic review was conducted that analysed studies reporting outcomes for elective surgery in the modern era (>2002). It was prospectively registered on the PROSPERO database (ref: CRD42018115513). Searches were performed of Embase and MEDLINE on 15 January 2019. Outcomes were split by operation performed. Primary outcome was quality of life; secondary outcomes were early, late and functional outcomes after surgery. Outcomes reported in five or more studies underwent a meta-analysis of incidence using random effects. Heterogeneity is reported with I2 , and publication bias was assessed using Doi plots and the Luis Furuya-Kanamori index. RESULTS: A total of 34 studies were included (11 774 patients). Quality of life was reported in 12 studies, with variable and contrasting results. Thirteen outcomes (eight early surgical complications, five functional outcomes) were included in the formal meta-analysis, all of which were outcomes for ileal pouch-anal anastomosis (IPAA). A further 71 outcomes were reported (50 IPAA, 21 end ileostomy). Only 14 of 84 outcomes received formal definitions, with high inter-study variation of definitions. CONCLUSION: Outcomes after elective surgery for UC are variably defined. This systematic review and meta-analysis highlights the range of reported incidences and provides practical information that facilitates shared decision making in clinical practice

    Cryoglobulinemic vasculitis in primary Sj\uf6gren's Syndrome: Clinical presentation, association with lymphoma and comparison with Hepatitis C-related disease

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    Objective: To describe the clinical spectrum of cryoglobulinemic vasculitis (CV) in primary Sj\uf6gren's syndrome (pSS), investigate its relation to lymphoma and identify the differences with hepatitis C virus (HCV) related CV. Methods: From a multicentre study population of consecutive pSS patients, those who had been evaluated for cryoglobulins and fulfilled the 2011 classification criteria for CV were identified retrospectively. pSS-CV patients were matched with pSS patients without cryoglobulins (1:2) and HCV-CV patients (1:1). Clinical, laboratory and outcome features were analyzed. A data driven logistic regression model was applied for pSS-CV patients and their pSS cryoglobulin negative controls to identify independent features associated with lymphoma. Results: 1083 pSS patients were tested for cryoglobulins. 115 (10.6%) had cryoglobulinemia and 71 (6.5%) fulfilled the classification criteria for CV. pSS-CV patients had higher frequency of extraglandular manifestations and lymphoma (OR=9.87, 95% CI: 4.7\u201320.9) compared to pSS patients without cryoglobulins. Purpura was the commonest vasculitic manifestation (90%), presenting at disease onset in 39% of patients. One third of pSS-CV patients developed B-cell lymphoma within the first 5 years of CV course, with cryoglobulinemia being the strongest independent lymphoma associated feature. Compared to HCV-CV patients, pSS-CV individuals displayed more frequently lymphadenopathy, type II IgMk cryoglobulins and lymphoma (OR = 6.12, 95% CI: 2.7\u201314.4) and less frequently C4 hypocomplementemia and peripheral neuropathy. Conclusion: pSS-CV has a severe clinical course, overshadowing the typical clinical manifestations of pSS and higher risk for early lymphoma development compared to HCV related CV. Though infrequent, pSS-CV constitutes a distinct severe clinical phenotype of pSS

    Relationship of endothelial shear stress with plaque features with coronary CT angiography and vasodilating capability with PET

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    Background: Advances in three-dimensional reconstruction techniques and computational fluid dynamics of coronary CT angiography (CCTA) data sets make feasible evaluation of endothelial shear stress (ESS) in the vessel wall.Purpose: To investigate the relationship between CCTA-derived computational fluid dynamics metrics, anatomic and morphologic characteristics of coronary lesions, and their comparative performance in predicting impaired coronary vasodilating capability assessed by using PET myocardial perfusion imaging (MPI).Materials and Methods: In this retrospective study, conducted between October 2019 and September 2020, coronary vessels in patients with stable chest pain and with intermediate probability of coronary artery disease who underwent both CCTA and PET MPI with oxygen 15-labeled water or nitrogen 13 ammonia and quantification of myocardial blood flow were analyzed. CCTA images were used in assessing stenosis severity, lesion-specific total plaque volume (PV), noncalcified PV, calcified PV, and plaque phenotype. PET MPI was used in assessing significant coronary stenosis. The predictive performance of the CCTA-derived parameters was evaluated by using area under the receiver operating characteristic curve (AUC) analysis.Results: There were 92 coronary vessels evaluated in 53 patients (mean age, 65 years +/- 7; 31 men). ESS was higher in lesions with greater than 50% stenosis versus those without significant stenosis (mean, 15.1 Pa +/- 30 vs 4.6 Pa +/- 4 vs 3.3 Pa +/- 3; P = .004). ESS was higher in functionally significant versus nonsignificant lesions (median, 7 Pa [interquartile range, 5-23 Pa] vs 2.6 Pa [interquartile range, 1.8-5 Pa], respectively; P <= .001). Adding ESS to stenosis severity improved prediction (change in AUC, 0.10; 95% CI: 0.04, 0.17; P =.002) for functionally significant lesions.Conclusion: The combination of endothelial shear stress with coronary CT angiography (CCTA) stenosis severity improved prediction of an abnormal PET myocardial perfusion imaging result versus CCTA stenosis severity alone. (C) RSNA, 2021Cardiolog

    Addressing the clinical unmet needs in primary Sjögren's Syndrome through the sharing, harmonization and federated analysis of 21 European cohorts

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    For many decades, the clinical unmet needs of primary Sjögren's Syndrome (pSS) have been left unresolved due to the rareness of the disease and the complexity of the underlying pathogenic mechanisms, including the pSS-associated lymphomagenesis process. Here, we present the HarmonicSS cloud-computing exemplar which offers beyond the state-of-the-art data analytics services to address the pSS clinical unmet needs, including the development of lymphoma classification models and the identification of biomarkers for lymphomagenesis. The users of the platform have been able to successfully interlink, curate, and harmonize 21 regional, national, and international European cohorts of 7,551 pSS patients with respect to the ethical and legal issues for data sharing. Federated AI algorithms were trained across the harmonized databases, with reduced execution time complexity, yielding robust lymphoma classification models with 85% accuracy, 81.25% sensitivity, 85.4% specificity along with 5 biomarkers for lymphoma development. To our knowledge, this is the first GDPR compliant platform that provides federated AI services to address the pSS clinical unmet needs. © 2022 The Author(s

    Breast cancer management pathways during the COVID-19 pandemic: outcomes from the UK ‘Alert Level 4’ phase of the B-MaP-C study

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    Abstract: Background: The B-MaP-C study aimed to determine alterations to breast cancer (BC) management during the peak transmission period of the UK COVID-19 pandemic and the potential impact of these treatment decisions. Methods: This was a national cohort study of patients with early BC undergoing multidisciplinary team (MDT)-guided treatment recommendations during the pandemic, designated ‘standard’ or ‘COVID-altered’, in the preoperative, operative and post-operative setting. Findings: Of 3776 patients (from 64 UK units) in the study, 2246 (59%) had ‘COVID-altered’ management. ‘Bridging’ endocrine therapy was used (n = 951) where theatre capacity was reduced. There was increasing access to COVID-19 low-risk theatres during the study period (59%). In line with national guidance, immediate breast reconstruction was avoided (n = 299). Where adjuvant chemotherapy was omitted (n = 81), the median benefit was only 3% (IQR 2–9%) using ‘NHS Predict’. There was the rapid adoption of new evidence-based hypofractionated radiotherapy (n = 781, from 46 units). Only 14 patients (1%) tested positive for SARS-CoV-2 during their treatment journey. Conclusions: The majority of ‘COVID-altered’ management decisions were largely in line with pre-COVID evidence-based guidelines, implying that breast cancer survival outcomes are unlikely to be negatively impacted by the pandemic. However, in this study, the potential impact of delays to BC presentation or diagnosis remains unknown

    The effect of generation-recombination mechanisms on the transient behavior of polycrystalline silicon transistors

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    We have investigated the switch-on transients of polycrystalline silicon thin film transistors. The investigation has been performed on devices fabricated on films with very long crystal domains obtained by excimer-laser annealing crystallization. The measurement of switch-on transient reveals that the device transient behavior depends significantly on both temperature and illumination. The temperature dependence, under dark and illumination, suggests that the mechanism accountable for the transient behavior of thin film transistors cannot be attributed only to carrier trapping but rather to a more complex mechanism involving carrier generation and recombination in the device body. © 2005 Elsevier B.V. All rights reserved

    Mechanical damage assessment by means of thermo-electrical lock-in thermography

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    The present work deals with the nondestructive assessment of the metallic materials' mechanical damage. An innovative Nondestructive Evaluation (NDE) methodology based on two thermographic approaches was developed in order the state of fatigue damage to be assessed. The first approach allows the detection of heat waves generated by the thermomechanical coupling during the fatigue loading (online method). Specifically, both the thermo-elastic and intrinsic dissipated energy was correlated with the mechanical degradation and the remaining fatigue life. The second approach involves the monitoring of the materials' thermal behavior using a Peltier device for accurate thermal excitation (offline method). The correlation of the thermal behavior and the state of damage was achieved by the determination of the material's thermal response. The combination of these two approaches enables the rapid and accurate assessment of the cumulative damag
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