DiffuseExpand: Expanding dataset for 2D medical image segmentation using diffusion models

Dataset expansion can effectively alleviate the problem of data scarcity for medical image segmentation, due to privacy concerns and labeling difficulties. However, existing expansion algorithms still face great challenges due to their inability of guaranteeing the diversity of synthesized images with paired segmentation masks. In recent years, Diffusion Probabilistic Models (DPMs) have shown powerful image synthesis performance, even better than Generative Adversarial Networks. Based on this insight, we propose an approach called DiffuseExpand for expanding datasets for 2D medical image segmentation using DPM, which first samples a variety of masks from Gaussian noise to ensure the diversity, and then synthesizes images to ensure the alignment of images and masks. After that, DiffuseExpand chooses high-quality samples to further enhance the effectiveness of data expansion. Our comparison and ablation experiments on COVID-19 and CGMH Pelvis datasets demonstrate the effectiveness of DiffuseExpand. Our code is released at https://anonymous.4open.science/r/DiffuseExpand.Comment: 10 pages, 5 figure

Deep Mouse: An End-to-end Auto-context Refinement Framework for Brain Ventricle and Body Segmentation in Embryonic Mice Ultrasound Volumes

High-frequency ultrasound (HFU) is well suited for imaging embryonic mice due to its noninvasive and real-time characteristics. However, manual segmentation of the brain ventricles (BVs) and body requires substantial time and expertise. This work proposes a novel deep learning based end-to-end auto-context refinement framework, consisting of two stages. The first stage produces a low resolution segmentation of the BV and body simultaneously. The resulting probability map for each object (BV or body) is then used to crop a region of interest (ROI) around the target object in both the original image and the probability map to provide context to the refinement segmentation network. Joint training of the two stages provides significant improvement in Dice Similarity Coefficient (DSC) over using only the first stage (0.818 to 0.906 for the BV, and 0.919 to 0.934 for the body). The proposed method significantly reduces the inference time (102.36 to 0.09 s/volume around 1000x faster) while slightly improves the segmentation accuracy over the previous methods using slide-window approaches.Comment: Full Paper Submission to ISBI 202

circARL15 Plays a Critical Role in Intervertebral Disc Degeneration by Modulating miR-431-5p/DISC1

BackgroundIntervertebral disk degeneration (IDD) is a serious public health problem associated with genetic and environmental factors. However, the pathogenic factors involved and the pathological mechanism of this disease still remain enigmatic.MethodsThe associated microarray was downloaded and further analyzed using statistical software R. The competing endogenous RNA (ceRNA) co-expression network was constructed to measure the meaningful correlated expression of differentially expressed genes. We further measured the expression of circARL15/miR-431-5p/DISC1 in IDD tissues. Cell proliferation and apoptosis were detected in NP cells transfected with a circARL15 overexpression plasmid and miR-431-5p mimics. The expression of DISC1 was detected by immunohistochemistry and Western blot analysis.ResultsWithin the ceRNA network, circARL15 is the most differentially expressed circular RNA. circARL15 was down-regulated in IDD and was negatively correlated with miR-431-5p and positively associated with DISC1. miR-431-5p was found to bind directly to circARL15 and DISC1. circARL15 inhibited nucleus pulposus cell apoptosis but promoted nucleus pulposus cell proliferation by targeting the miR-431-5p/DISC1 signaling pathway.ConclusioncircARL15/miR-431-5p/DISC1 is involved in the pathogenesis of IDD, which might be helpful in determining the diagnostic biomarkers and providing potential therapeutic targets for patients with IDD

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

Test platform design for regenerative braking of hub-motor

Electric brake experiment of hub-motor is preliminary basis of the regeneration braking control strategy. A regenerative braking test bench of hub-motor is designed in which the test and control system is developed based on Labview and NI virtual instrument. The physical structure, signal acquisition hardware and test system principle of the bench are introduced. The bench can test torque and speed of the hub-motor, on which the electric brake experiment and etc. can be done. Through the unloaded glide and electric brake experiments, the results show that the design of the bench is reasonable and control modes of the test and control system is feasible. Furthermore, the test bench can provide important references for regeneration braking control strategy and motor performance tests

Modified fictitious play

We describe a modification of Brown\u27s fictitious play method for solving matrix (zero-sum two-person) games and apply it to both symmetric and general games. If the original game is not symmetric, the basic idea is to transform the given matrix game into an equivalent symmetric game (a game with a skew-symmetric matrix) and use the solution properties of symmetric games (the game value is zero and both players have the same optimal strategies). The fictitious play method is then applied to the enlarged skew-symmetric matrix with a modification that calls for the periodic restarting of the process. At restart, both players\u27 strategies are made equal based on the following considerations: Select the maximizing or minimizing player\u27s strategy that has a game value closest to zero. We show for both symmetric and general games, and for problems of varying sizes, that the modified fictitious play (MFP) procedure approximates the value of the game and optimal strategies in a greatly reduced number of iterations and in less computational time when compared to Brown\u27s regular fictitious play (RFP) method. For example, for a randomly generated 50% dense skew-symmetric 100 X 100 matrix (symmetric game), with coefficients |aij| ≤ 100, it took RFP 2,652,227 iterations to reach a gap of 0.03118 between the lower and upper bounds for the game value in 70.71 s, whereas it took MFP 50,000 iterations to reach a gap of 0.03116 in 1.70 s. Improved results were also obtained for general games in which the MFP solves a much larger equivalent symmetric game. © 1996 John Wiley & Sons. Inc

Transboundary Water Cooperation in the Post-Cold War Era: Spatial Patterns and the Role of Proximity

Transboundary water cooperation (TWC) is an important theme of international cooperation. We conducted macro-level research on TWC from the perspective of inter-country relations and constructed a theoretical framework in which multidimensional proximity influences the formation of global TWC. We explained how multidimensional proximity and the constituent elements comprehensively influence the cooperative willingness and ability of actors, which directly drive the generation of global TWC. During the empirical research phase, we constructed the TWC frequency and intensity networks based on historical TWC events data from 1992 to 2013. By using social network analysis and QAP regression analysis, the spatial structure and proximity effect of water cooperation linkages are examined. It can be found that: (1) the reconstruction of territorial space on the eve of the end of the Cold War led to the peak of water cooperation events in 1992. The overall scale of events in the Post-Cold War era was relatively high and fluctuated steadily. (2) Water cooperation linkages have distinct spatial heterogeneity and are concentrated in the Eurasian and the African continents. Water cooperation is sensitive to geographical distance, and high-intensity water cooperation linkages exist in only a few areas. (3) China, Egypt, Germany, the United States, and Russia have prominent positions in the network. The United States, Japan, and other extra-regional powers actively participated in TWC in the Eastern Hemisphere. (4) The regression results show that geographical, economic, organizational, and colonial proximity significantly affect the intensity of water cooperation among countries

Analysis of Traction and Unfolding Dynamics of Space-Symmetric Flexible Webs for UAV Interception and Capture

A new type of flexible web with a spatial symmetry structure is proposed to address the interception and acquisition of UAVs. It is different from the existing flexible web structure. According to the mechanical characteristics of the flexible web, the dynamic analysis model of the flexible web is established through theoretical deduction. Through finite element simulation calculation, the flexible webs of three different spatial symmetric structures are compared and analyzed. The internal force and air attitude of the three flexible webs are discussed. Among them, the new flexible web has a lag time of 0.162 s and a flight height of 11.624 m. The above simulation parameters are better than those of the other two symmetrical structures. It was proved that the new spatial symmetric flexible web has good traction and deployment performance. In addition, a ground verification test is designed and carried out. The web attitude and flight altitude parameters are compared with the simulation and test results. It is found that the simulation and experimental process of the new symmetric structure web are in good agreement, the synchronization of attitude change is good, and the flight altitude error of the two is controlled at about 5%. The feasibility and effectiveness of this method are proven and it can provide a reference for the research of flexible interception and acquisition of UAVs

Analysis of Traction and Unfolding Dynamics of Space-Symmetric Flexible Webs for UAV Interception and Capture

A new type of flexible web with a spatial symmetry structure is proposed to address the interception and acquisition of UAVs. It is different from the existing flexible web structure. According to the mechanical characteristics of the flexible web, the dynamic analysis model of the flexible web is established through theoretical deduction. Through finite element simulation calculation, the flexible webs of three different spatial symmetric structures are compared and analyzed. The internal force and air attitude of the three flexible webs are discussed. Among them, the new flexible web has a lag time of 0.162 s and a flight height of 11.624 m. The above simulation parameters are better than those of the other two symmetrical structures. It was proved that the new spatial symmetric flexible web has good traction and deployment performance. In addition, a ground verification test is designed and carried out. The web attitude and flight altitude parameters are compared with the simulation and test results. It is found that the simulation and experimental process of the new symmetric structure web are in good agreement, the synchronization of attitude change is good, and the flight altitude error of the two is controlled at about 5%. The feasibility and effectiveness of this method are proven and it can provide a reference for the research of flexible interception and acquisition of UAVs