•Considered various kinds of situations.•Certify the capability for classification Identification of initial enrichment and burn-up.•Trying to explain the result from mathematics in physics.•More ...statistical methods will be used in the future.
The proposed study focuses on the development of multivariate statistical analysis to interpret the comparative signatures of spent nuclear fuel. A database was built with Uranium and Plutonium isotopic compositions of spent nuclear fuel samples through simulation. These samples are in different reactor types, initial fuel enrichments and burn-ups. As a preliminary study, factor analysis is applied to the database to certify the feasibility of the possible origin-determination work. At first, dimension reduction and visualization work is realized to decide the possibility for classification. Then, some known samples are assumed to be unknown to further study the possible capabilities for quantitative attribution, containing the determination of initial fuel enrichment and burn-up.
Imaging biomarkers, such as the collateral score as determined from Computed Tomography Angiography (CTA) images, play a role in treatment decision making for acute stroke patients. In this ...manuscript, we present an end-to-end learning approach for automatic determination of a collateral score from a CTA image. Our aim was to investigate whether such end-to-end learning approaches can be used for this classification task, and whether the resulting classification can be used in existing outcome prediction models.
The method consists of a preprocessing step, where the CTA image is aligned to an atlas and divided in the two hemispheres: the affected side and the healthy side. Subsequently, a VoxResNet based convolutional neural network is used to extract features at various resolutions from the input images. This is done by using a Siamese model, such that the classification is driven by the comparison between the affected and healthy using a unique set of features for both hemispheres. After masking the resulting features for both sides with the vascular region and global average pooling (per hemisphere) and concatenation of the resulting features, a fully connected layer is used to determine the categorized collateral score.
Several experiments have been performed to optimize the model hyperparameters and training procedure, and to validate the final model performance. The hyperparameter optimization and subsequent model training was done using CTA images from the MR CLEAN Registry, a Dutch multi-center multi-vendor registry of acute stroke patients that underwent endovascular treatment. A separate set of images, from the MR CLEAN Trial, served as an external validation set, where collateral scoring was assessed and compared with both human observers and a recent more traditional model. In addition, the automated collateral scores have been used in an existing functional outcome prediction model that uses both imaging and non-imaging clinical parameters.
The results show that end-to-end learning of collateral scoring in CTA images is feasible, and does perform similar to more traditional methods, and the performance also is within the inter-observer variation. Furthermore, the results demonstrate that the end-to-end classification results also can be used in an existing functional outcome prediction model.
A series of novel 5‐amido‐2‐carboxypyrazine derivatives were designed, synthesized and evaluated for the inhibitory activities against the T3SS of Salmonella enterica serovar Typhimurium. Preliminary ...results displayed that the compounds 2f, 2g, 2h and 2i showed potent inhibitory activities against T3SS. Compound 2h was identified as the most potent T3SS inhibitor and the SPI‐1 effector secretion was strongly inhibited by 2h in a dose‐dependent manner. The effects of compound 2h on the SPI‐1 genes transcription might be via impacting the SicA/InvF regulatory pathway.
Compound 2h was identified as the most potent inhibitor of T3SS, which showed strong inhibitory effects on the secretion of the SPI‐1 effector proteins in a dose‐dependent manner. The compound 2h might affect the SPI‐1 genes transcription via impacting the SicA/InvF regulatory pathway.
Recent years, the work of nuclear forensics has been greatly promoted in many aspects, and an important work is the establishment and application of nuclear forensic database. For now, this research ...is mainly based on uranium ore, because there is plenty of uranium ore information that is open and is easy to form database available for attribution. However, as the potential threat of spent nuclear fuel gets more and more attention, the number of researches on the identification of spent nuclear fuel via database is increasing. Since there is no public spent nuclear fuel database that is proper for attribution, such kind of work is mainly on methodology study. This paper focuses on the use of database for the identification of spent nuclear fuel. A database is first constructed with numerical simulation results and is used to identify samples both from simulation and experimental measurements to study the availability and applicability. Then samples from real database are used to optimize the database constructed with simulation result to better meet the need of real nuclear forensics scenarios.
•Identification of reactor type, initial enrichment and burn-up for experimental measurement data via multivariate analysis.•Comparison between the identification results of simulated samples and experimental measurement data.•Optimizations for the database for each identification need to meet the actual need.
Purpose
Outcome of endovascular treatment in acute ischemic stroke patients is depending on the collateral circulation maintaining blood flow to the ischemic territory. We evaluated the inter-rater ...reliability and accuracy of raters and an automated algorithm for assessing the collateral score (CS, range: 0–3) in acute ischemic stroke patients.
Methods
Baseline CTA scans with an intracranial anterior occlusion from the MR CLEAN study (
n
=500) were used. For each core lab CS, ten CTA scans with sufficient quality were randomly selected. After a training session in collateral scoring, all selected CTA scans were individually evaluated for a visual CS by three groups: 7 radiologists, 13 junior and 9 senior radiology residents. Two additional radiologists scored CS to be used as reference, with a third providing a CS to produce a 2 out of 3 consensus CS in case of disagreement. An automated algorithm was also used to compute CS. Inter-rater agreement was reported with intraclass correlation coefficient (ICC). Accuracy of visual and automated CS were calculated.
Results
39 CTA scans were assessed (1 corrupt CTA-scan excluded). All groups showed a moderate ICC (0.689-0.780) in comparison to the reference standard. Overall human accuracy was 65± 7% and increased to 88± 5% for dichotomized CS (0–1, 2–3). Automated CS accuracy was 62%, and 90% for dichotomized CS. No significant difference in accuracy was found between groups with different levels of expertise.
Conclusion
After training, inter-rater reliability in collateral scoring was not influenced by experience. Automated CS performs similar to residents and radiologists in determining a collateral score.
Extracting the cerebral anterior vessel tree of patients with an intracranial large vessel occlusion (LVO) is relevant to investigate potential biomarkers that can contribute to treatment decision ...making. The purpose of our work is to develop a method that can achieve this from routinely acquired computed tomography angiography (CTA) and computed tomography perfusion (CTP) images.
To this end, we regard the anterior vessel tree as a set of bifurcations and connected centerlines. The method consists of a proximal policy optimization (PPO) based deep reinforcement learning (DRL) approach for tracking centerlines, a convolutional neural network based bifurcation detector, and a breadth-first vessel tree construction approach taking the tracking and bifurcation detection results as input. We experimentally determine the added values of various components of the tracker. Both DRL vessel tracking and CNN bifurcation detection were assessed in a cross validation experiment using 115 subjects. The anterior vessel tree formation was evaluated on an independent test set of 25 subjects, and compared to interobserver variation on a small subset of images.
The DRL tracking result achieves a median overlapping rate until the first error (1.8 mm off the reference standard) of 100, 46, 100 % on 8032 vessels over 115 subjects. The bifurcation detector reaches an average recall and precision of 76% and 87% respectively during the vessel tree formation process. The final vessel tree formation achieves a median recall of 68% and precision of 70%, which is in line with the interobserver agreement.
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In this study, an AgBr/Ag
PO
(ABAP) photocatalyst has been prepared
a facile one-pot anion-exchange method. SEM, XRD, XPS and UV-Vis DRS characterization techniques are carried out to study the ...structural and physicochemical characteristics of the AgBr/Ag
PO
composites. The ABAP photocatalyst exhibited outstanding photocatalytic capability for the photodegradation of rhodamine B (RhB) under visible light irradiation. The optimal ABAP-48% composite displayed the highest photocatalytic activity; a complete degradation was attained in 25 min under visible light irradiation. The excellent stability and reusability of ABAP catalysts were examined by five subsequent runs. A probable degradation mechanism of ABAP composites was carefully surveyed. Furthermore, radical trapping experiments confirmed that the ˙O
radical was the main active species in the photodegradation reaction.
Automatic Collateral Scoring From 3D CTA Images Su, Jiahang; Wolff, Lennard; van Es, Adriaan C. G. M ...
IEEE transactions on medical imaging,
06/2020, Letnik:
39, Številka:
6
Journal Article
Odprti dostop
The collateral score is an important biomarker in decision making for endovascular treatment (EVT) of patients with ischemic stroke. The existing collateral grading systems are based on visual ...inspection and prone to subjective interpretation and interobserver variation. The purpose of our work is the development of an automatic collateral scoring method. In this work, we present a method that is inspired by human collateral scoring. Firstly, we define an anatomical region by atlas-based registration and extract vessel structures using a deep convolutional neural network. From this, high-level features based on the ratios of vessel length and volume of the occluded and the contralateral side are defined. Multi-class classification models are used to map the feature space to a four-grade collateral score and a quantitative score. The dataset used for training, validation and testing is from a registry of images acquired in clinical routine at multiple medical centers. The model performance is tested on 269 subjects, achieving an accuracy of 0.8. The dichotomized collateral score accuracy is 0.9. The error is comparable to the interobserver variation, the results are comparable to the performance of two radiologists with 10 to 30 years of experience.
•Novel linear relationships in the complex reactions of PWR are suggested between fuel enrichment, burnup, and ratios of isotopic concentrations.•Linear relationships are verified from theoretical ...analysis, the SFCOMPO-2.0 experimental data, and two neutronic codes.•It is helpful for nuclear forensics, reactor operation, and a deeper understanding of the complex nonlinear reactions.
In the process of nuclear forensics, burnup and initial fuel enrichment are two important tracing indicators. They are generally related to the isotopic components by a highly nonlinear depletion-coupled transport equation. However, some linear correlations in Pressurized Water Reactor (PWR) have been found experimentally based on a few fuel samples. The present work explores convinced linear correlations among the nonlinear transport-depletion problem in the nuclear reactors, between the element components of spent fuel and its burnup (initial enrichment). Firstly, thelinear relationshipsamong nonlineartransport-depletion problems are derived from the Bateman equation, which indicates that theratios of important nuclidesin spent fuel could be approximated by a limited burnup. Secondly, the linear relationships between the fuel enrichment, burnup, and ratios of isotopic concentrations have been tested by experimental and simulated data. The result shows that the linear relationships are satisfied in typical PWR.
To study the effect and molecular mechanisms of amlodipine besylate combined with acupoint application of traditional Chinese medicine nursing on the treatment methods of renal failure and ...hypertension. A total of 60 cases of renal failure hypertension were randomly divided into the Control group and the Treatment group. The control group was treated with amlodipine besylate, while the treatment group was treated with amlodipine besylate combined with acupoint application of traditional Chinese medicine nursing. A rat model of renal failure hypertension was established. Rats were divided into the sham group, model group, NC group (treated with amlodipine besylate) and treatment group (treated with amlodipine besylate combined with acupoint application of traditional Chinese medicine nursing). Rats were given drugs at 10-20 weeks of age to observe their general condition and detect changes of blood pressure, blood biochemical indices and urine index. The pathological changes of renal tissue were examined by hematoxylin and eosin staining, and the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinase (MMP)9 were detected by immunohistochemistry. Reverse transcription-quantitative polymerase chain reaction was used to determine mRNA expression of phosphoinositide 3-kinase (PI3K), protein kinase B (AKT) and endothelin (ET)-l and western blotting was used to detect the expression of phosphorylated (p)-PI3K/PI3K, p-AKT/AKT and p-nuclear factor (NF)-kappaB p65/NF-kappaB p65 protein. Systolic and diastolic blood pressures in Treated group patients were significantly lower compared with in Control group patients. The systolic and diastolic blood pressure of rats were significantly decreased and blood urea nitrogen (BUN), carbapenem-resistant Enterobacteriaceae (CRE), N-acetyl-beta-D-glucosaminidase (NAG), urine protein (UP) and blood urea protein (BUP), contents were significantly decreased following amlodipine besylate treatment. The expression of VEGF and matrix metallopeptidase 9 protein were significantly decreased, but the expression of PI3K, AKT mRNA and p-PI3K/PI3K, p-AKT/AKT protein were significantly increased. ET-1 mRNA and p-NF-kappaB p65/NF-kappaB protein were significantly increased. The pathological alterations of renal tissue were improved and the pathological changes of glomerulus, tubule and interstitium were alleviated. Amlodipine besylate combined with acupoint application of traditional Chinese medicine nursing can effectively reduce the systolic pressure and diastolic pressure of patients, and improve the symptoms and signs of patients, which may be associated with the regulation of the expression of PI3K/AKT pathway, so as to regulate the expression of BUN, CRE, UP, BUP and NAG.
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