42 research outputs found

    Atrial Septal Defect Detection in Children Based on Ultrasound Video Using Multiple Instances Learning

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    Purpose: Congenital heart defect (CHD) is the most common birth defect. Thoracic echocardiography (TTE) can provide sufficient cardiac structure information, evaluate hemodynamics and cardiac function, and is an effective method for atrial septal defect (ASD) examination. This paper aims to study a deep learning method based on cardiac ultrasound video to assist in ASD diagnosis. Materials and methods: We select two standard views of the atrial septum (subAS) and low parasternal four-compartment view (LPS4C) as the two views to identify ASD. We enlist data from 300 children patients as part of a double-blind experiment for five-fold cross-validation to verify the performance of our model. In addition, data from 30 children patients (15 positives and 15 negatives) are collected for clinician testing and compared to our model test results (these 30 samples do not participate in model training). We propose an echocardiography video-based atrial septal defect diagnosis system. In our model, we present a block random selection, maximal agreement decision and frame sampling strategy for training and testing respectively, resNet18 and r3D networks are used to extract the frame features and aggregate them to build a rich video-level representation. Results: We validate our model using our private dataset by five-cross validation. For ASD detection, we achieve 89.33 AUC, 84.95 accuracy, 85.70 sensitivity, 81.51 specificity and 81.99 F1 score. Conclusion: The proposed model is multiple instances learning-based deep learning model for video atrial septal defect detection which effectively improves ASD detection accuracy when compared to the performances of previous networks and clinical doctors

    Low temperature and temperature decline increase acute aortic dissection risk and burden: A nationwide case crossover analysis at hourly level among 40,270 patients.

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    Background: Acute aortic dissection (AAD) is a life-threatening cardiovascular emergency with high mortality, so identifying modifiable risk factors of AAD is of great public health significance. The associations of non-optimal temperature and temperature variability with AAD onset and the disease burden have not been fully understood. Methods: We conducted a time-stratified case-crossover study using a nationwide registry dataset from 1,868 hospitals in 313 Chinese cities. Conditional logistic regression and distributed lag models were used to investigate associations of temperature and temperature changes between neighboring days (TCN) with the hourly AAD onset and calculate the attributable fractions. We also evaluated the heterogeneity of the associations. Findings: A total of 40,270 eligible AAD cases were included. The exposure-response curves for temperature and TCN with AAD onset risk were both inverse and approximately linear. The risks were present on the concurrent hour (for temperature) or day (for TCN) and lasted for almost 1 day. The cumulative relative risks of AAD were 1.027 and 1.026 per 1°C lower temperature and temperature decline between neighboring days, respectively. The associations were significant during the non-heating period, but were not present during the heating period in cities with central heating. 23.13% of AAD cases nationwide were attributable to low temperature and 1.58% were attributable to temperature decline from the previous day. Interpretation: This is the largest nationwide study demonstrating robust associations of low temperature and temperature decline with AAD onset. We, for the first time, calculated the corresponding disease burden and further showed that central heating may be a modifier for temperature-related AAD risk and burden. Funding: This work was supported by the National Natural Science Foundation of China (92043301 and 92143301), Shanghai International Science and Technology Partnership Project (No. 21230780200), the Medical Research Council-UK (MR/R013349/1), and the Natural Environment Research Council UK (NE/R009384/1)

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Mechanical and durability performance of concrete with recycled tire steel fibers

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    The increasing waste tire disposal and the related environmental pollution have led to the further exploration of utilizing recycled-tire steel fiber (RTSF) to replace industrial steel fiber (ISF) for better cost-effective concrete production. This study compares the workability, mechanical properties, and durability of RTSF-reinforced concrete (RSC) to those of commercial ISF-reinforced concrete (ISC). Plain concrete samples, ISC samples named IS05 and IS05R (with 0.5% of ISF by volume), and RSC samples named RS05, RS10, and RS15 with three-volume percentages of RTSF (0.5%, 1.0%, and 1.5%) were prepared accordingly. The results show that RSC has better flowability than ISC when adding the same volume percentage of fibers. In terms of mechanical properties, the addition of RTSF slightly increases the 28-day compressive strength. The splitting tensile strength is also increased by up to 15.4% with the added RTSF, which is very close to the ISF (16.9%). Regarding flexural performance, RS15 samples show a very close enhancing effect to IS05 samples with enlarged residual strength and fracture energy. The ultrasonic pulse velocity test results also indicate that both RTSF and ISF slightly increase the concrete modulus. In terms of durability, RS10 samples reduce drying shrinkage by up to 9.2%, which is better than IS05 samples (6.3%). RTSF also improves the freeze–thaw resistance by reducing the change percentage of relative dynamic modulus and increasing the durability factor by up to 4.6%. Overall, the RTSFs in concrete have a slightly lower mechanical reinforcement and better workability by comparing with one type of thin ISFs. These findings can facilitate the usage of RTSF in concrete mixes as mechanical reinforcements and provide another market for waste tire fiber recycling

    Synchronized array MT sounding in mountain areas

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    Investigation of the mechanical and shrinkage properties of plastic-rubber compound modified cement mortar with recycled tire steel fiber

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    To facilitate the recycling of waste solids in cement-based materials, plastic-rubber (PR) compound modified mortar (PRM) samples and recycled steel fiber (RSF)-reinforced plastic-rubber modified mortar (PRSRM) samples were prepared and tested to evaluate their mechanical and drying shrinkage properties. PR compound particles, with a mesh size of #8, replaced the natural aggregates with four volume percentages: 2%, 5%, 7.5%, and 10%. The fiber was added with a constant volume fraction of 0.2%. Accordingly, control mortar, PRM mortar with different PR replacement ratios, and PRSRM mortar with RSF were prepared and tested. A numerical splitting tension test model was also established based on the two-dimensional Distinct Element Method (DEM) to investigate the crack initiation and propagation mechanism of the PRM samples. The mechanical test results indicated that the addition of RSF enlarged the compressive strength by 14–27% PRM samples. Meanwhile, both PR and RSF improved mortar flexural behavior by increasing the fracture energy. The SEM image of a fracture surface and DEM simulation showed the crack propagation path was changed by PR particles due to its lower stiffness. Meanwhile, the 7-days drying shrinkage length change was reduced by about 25% due to the PR\u27s porous structure and water-retaining ability. Overall, the sustainable material design with the combination of PR and RSF would promote the full-recycling of waste tires in cement-based materials
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