195 research outputs found
Electron Bunch Train Excited Higher-Order Modes in a Superconducting RF Cavity
Higher-order mode (HOM) based intra-cavity beam diagnostics has been proved
effectively and conveniently in superconducting radio-frequency (SRF)
accelerators. Our recent research shows that the beam harmonics in the bunch
train excited HOM spectrum, which have much higher signal-to-noise ratio than
the intrinsic HOM peaks, may also be useful for beam diagnostics. In this
paper, we will present our study on bunch train excited HOMs, including the
theoretic model and recent experiments carried out based on the DC-SRF
photoinjector and SRF linac at Peking University.Comment: Supported by National Natural Science Foundation of China (11275014
LDCSF: Local depth convolution-based Swim framework for classifying multi-label histopathology images
Histopathological images are the gold standard for diagnosing liver cancer.
However, the accuracy of fully digital diagnosis in computational pathology
needs to be improved. In this paper, in order to solve the problem of
multi-label and low classification accuracy of histopathology images, we
propose a locally deep convolutional Swim framework (LDCSF) to classify
multi-label histopathology images. In order to be able to provide local field
of view diagnostic results, we propose the LDCSF model, which consists of a
Swin transformer module, a local depth convolution (LDC) module, a feature
reconstruction (FR) module, and a ResNet module. The Swin transformer module
reduces the amount of computation generated by the attention mechanism by
limiting the attention to each window. The LDC then reconstructs the attention
map and performs convolution operations in multiple channels, passing the
resulting feature map to the next layer. The FR module uses the corresponding
weight coefficient vectors obtained from the channels to dot product with the
original feature map vector matrix to generate representative feature maps.
Finally, the residual network undertakes the final classification task. As a
result, the classification accuracy of LDCSF for interstitial area, necrosis,
non-tumor and tumor reached 0.9460, 0.9960, 0.9808, 0.9847, respectively.
Finally, we use the results of multi-label pathological image classification to
calculate the tumor-to-stromal ratio, which lays the foundation for the
analysis of the microenvironment of liver cancer histopathological images.
Second, we released a multilabel histopathology image of liver cancer, our code
and data are available at https://github.com/panliangrui/LSF.Comment: Submitted to BIBM202
CVFC: Attention-Based Cross-View Feature Consistency for Weakly Supervised Semantic Segmentation of Pathology Images
Histopathology image segmentation is the gold standard for diagnosing cancer,
and can indicate cancer prognosis. However, histopathology image segmentation
requires high-quality masks, so many studies now use imagelevel labels to
achieve pixel-level segmentation to reduce the need for fine-grained
annotation. To solve this problem, we propose an attention-based cross-view
feature consistency end-to-end pseudo-mask generation framework named CVFC
based on the attention mechanism. Specifically, CVFC is a three-branch joint
framework composed of two Resnet38 and one Resnet50, and the independent branch
multi-scale integrated feature map to generate a class activation map (CAM); in
each branch, through down-sampling and The expansion method adjusts the size of
the CAM; the middle branch projects the feature matrix to the query and key
feature spaces, and generates a feature space perception matrix through the
connection layer and inner product to adjust and refine the CAM of each branch;
finally, through the feature consistency loss and feature cross loss to
optimize the parameters of CVFC in co-training mode. After a large number of
experiments, An IoU of 0.7122 and a fwIoU of 0.7018 are obtained on the
WSSS4LUAD dataset, which outperforms HistoSegNet, SEAM, C-CAM, WSSS-Tissue, and
OEEM, respectively.Comment: Submitted to BIBM202
pN1 but not pN0/N2 predicts survival benefits of prophylactic cranial irradiation in small-cell lung cancer patients after surgery.
Background
Prophylactic cranial irradiation has been shown to reduce brain metastases and provide survival benefits in small-cell lung cancer (SCLC). However, its role in limited-stage SCLC patients after surgery remains unclear. Further, it is unknown whether the effect of prophylactic cranial irradiation is generalizable in these patients with different pathological nodal (N0-N2) stages, a state indicating the presence of tumor metastases.
Methods
We combined data from a single medical center and Surveillance, Epidemiology, and End Results database. Propensity score matching analyses were performed (1:2) to evaluate the role of prophylactic cranial irradiation in SCLC patients after surgery. Cox proportional hazards regression model was used to identify predictors of survival.
Results
124 (18.7%) out of 664 surgically-treated SCLC patients received prophylactic cranial irradiation treatment. Within the entire cohort, multivariate Cox regression analysis identified dataset source, age, pathological T and N stages, adjuvant chemotherapy, resection type, and histology as independent prognostic factors for overall survival. Prophylactic cranial irradiation appeared to be associated with a better overall survival, but the difference is marginally significant (P=0.063). Further, we stratified patients based on the pathological N0-N2 stages using propensity score matching analyses, which showed that prophylactic cranial irradiation treatment was superior to non-prophylactic cranial irradiation treatment for surgically-treated SCLC patients with N1 stage only (univariate analysis: P=0.026; multivariate Cox: P=0.004), but not N0/N2 stage (univariate analysis: P=0.65 and P=0.28, respectively; multivariate Cox: P=0.99 and P=0.35, respectively).
Conclusions
Prophylactic cranial irradiation provides survival benefits for SCLC patients with pN1 after surgery but not with pathological N0/N2 stage. Our findings may provide helpful stratifications for clinical decision-making of prophylactic cranial irradiation intervention in SCLC patients
Self-Lubricating Polytetrafluoroethylene/Polyimide Blends Reinforced with Zinc Oxide Nanoparticles
ZnO nanoparticle reinforced polytetrafluoroethylene/polyimide (PTFE/PI) nanocomposites were prepared and their corresponding tribological and mechanical properties were studied in this work. The influences of ZnO loading, sliding load, and velocity on the tribological properties of ZnO/PTFE/PI nanocomposites were systematically investigated. Results reveal that nanocomposites reinforced with 3 wt% ZnO exhibit the optimal tribological and mechanical properties. Specifically, the wear loss decreased by 20% after incorporating 3 wt% ZnO compared to unfilled PTFE/PI. Meanwhile, the impact strength, tensile strength, and elongation-at-break of 3 wt% ZnO/PTFE/PI nanocomposite are enhanced by 85, 5, and 10% compared to pure PTFE/PI blend. Microstructure investigation reveals that ZnO nanoparticles facilitate the formation of continuous, uniform, and smooth transfer film and thus reduce the adhesive wear of PTFE/PI
Multi-Head Attention Mechanism Learning for Cancer New Subtypes and Treatment Based on Cancer Multi-Omics Data
Due to the high heterogeneity and clinical characteristics of cancer, there
are significant differences in multi-omics data and clinical features among
subtypes of different cancers. Therefore, the identification and discovery of
cancer subtypes are crucial for the diagnosis, treatment, and prognosis of
cancer. In this study, we proposed a generalization framework based on
attention mechanisms for unsupervised contrastive learning (AMUCL) to analyze
cancer multi-omics data for the identification and characterization of cancer
subtypes. AMUCL framework includes a unsupervised multi-head attention
mechanism, which deeply extracts multi-omics data features. Importantly, a
decoupled contrastive learning model (DMACL) based on a multi-head attention
mechanism is proposed to learn multi-omics data features and clusters and
identify new cancer subtypes. This unsupervised contrastive learning method
clusters subtypes by calculating the similarity between samples in the feature
space and sample space of multi-omics data. Compared to 11 other deep learning
models, the DMACL model achieved a C-index of 0.002, a Silhouette score of
0.801, and a Davies Bouldin Score of 0.38 on a single-cell multi-omics dataset.
On a cancer multi-omics dataset, the DMACL model obtained a C-index of 0.016, a
Silhouette score of 0.688, and a Davies Bouldin Score of 0.46, and obtained the
most reliable cancer subtype clustering results for each type of cancer.
Finally, we used the DMACL model in the AMUCL framework to reveal six cancer
subtypes of AML. By analyzing the GO functional enrichment, subtype-specific
biological functions, and GSEA of AML, we further enhanced the interpretability
of cancer subtype analysis based on the generalizable AMUCL framework
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