15 research outputs found
A CT-Based Airway Segmentation Using U-net Trained by the Dice Loss Function
Airway segmentation from chest computed tomography scans has played an
essential role in the pulmonary disease diagnosis. The computer-assisted airway
segmentation based on the U-net architecture is more efficient and accurate
compared to the manual segmentation. In this paper we employ the U-net
trained by the Dice loss function to model the airway tree from the multi-site
CT scans based on 299 training CT scans provided by the ATM'22. The derived
saliency probability map from the training is applied to the validation data to
extract the corresponding airway trees. The observation shows that the majority
of the segmented airway trees behave well from the perspective of accuracy and
connectivity. Refinements such as non-airway regions labeling and removing are
applied to certain obtained airway tree models to display the largest component
of the binary results.Comment: 8 pages, 5 figure
Myeloid deletion of phosphoinositide-dependent kinase-1 enhances NK cell-mediated antitumor immunity by mediating macrophage polarization
A large number of heterogeneous macrophages can be observed in solid tumor lesions. Classically activated M1 macrophages are a powerful killer of cancer cells. In contrast, tumor-associated macrophages (TAMs) are often referred to as M2 phenotype and usually impair tumor immunity mediated by cytotoxic lymphocytes, natural killer (NK) cells and CD8+ T cells. Therefore, orchestrating M2 to M1 reprogramming will provide a promising approach to tumor immunotherapy. Here we used a PyMT-induced spontaneous breast cancer model in which M2-polarized macrophages were abundant. This M2 phenotype was closely related to tumor progression and immune dysfunction of NK cells and CD8+ T cells. We then found that these TAMs showed increased energy expenditure and over-activation of two kinases, Akt and mammalian target of rapamycin (mTOR). Myeloid inactivation of phosphoinositide-dependent kinase-1 (PDK1), the upstream regulator for Akt and mTOR signaling, significantly reduced excessive metabolic activation of macrophages. Notably, the loss of PDK1 significantly led to regression of breast cancer and prevented lung metastasis. Mechanistically, PDK1 deficiency mainly inhibited the activation of mTOR complex 1 (mTORC1), transforming TAMs into M1 phenotype, thereby reversing tumor-related dysfunction of T cells and NK cells. Therefore, targeting PDK1 may be a new approach for M2 macrophage-enriched solid tumor immunotherapy
Parameter Identification of Fractional-Order Discrete Chaotic Systems
Research on fractional-order discrete chaotic systems has grown in recent years, and chaos synchronization of such systems is a new topic. To address the deficiencies of the extant chaos synchronization methods for fractional-order discrete chaotic systems, we proposed an improved particle swarm optimization algorithm for the parameter identification. Numerical simulations are carried out for the Hénon map, the Cat map, and their fractional-order form, as well as the fractional-order standard iterated map with hidden attractors. The problem of choosing the most appropriate sample size is discussed, and the parameter identification with noise interference is also considered. The experimental results demonstrate that the proposed algorithm has the best performance among the six existing algorithms and that it is effective even with random noise interference. In addition, using two samples offers the most efficient performance for the fractional-order discrete chaotic system, while the integer-order discrete chaotic system only needs one sample
Decentralized robust interaction control of modular robot manipulators via harmonic drive compliance model-based human motion intention identification
Abstract In this paper, a human motion intention estimation-based decentralized robust interaction control method of modular robot manipulators (MRMs) is proposed under the situation of physical human–robot interaction (pHRI). Different from traditional interaction control scheme that depends on the biological signal and centralized control method, the decentralized robust interaction control is implemented that using only position measurements of each joint module in this investigation. Based on the harmonic drive compliance model, a novel torque-sensorless human motion intention estimation method is developed, which utilizes only the information of local dynamic position measurements. On this basis, the decentralized robust interaction control scheme is presented to achieve high performance of position tracking and ensure the security of interaction to create the ’safety’ interaction environment. The uniformly ultimately bounded (UUB) of the tracking error is proved by the Lyapunov theory. Finally, pHRI experiments confirm the effectiveness and advancement of the proposed method
Characterization and phylogenetic analysis of the mitochondrial genome of Sarcocheilichthys sinensis (Bleeker) from Baima Hu Lake
Sarcocheilichthys sinensis (Bleeker), is a small-sized benthopelagic fish with ornamental value. In the present study, the complete mitochondrial genome of S. sinensis was sequenced and determined. The complete mitogenome of S. sinensis was 16,683 bp in length, consisting of 22 tRNA genes, 13 protein-coding genes, 2 rRNA genes, and 2 non-coding regions. The overall base composition of the S. sinensis mitogenome is 30.50% A, 26.28% T, 26.60% C, and 16.61% G, exhibiting obvious AT bias (56.79%). The phylogenetic analysis showed that S. sinensis clustered in genus Sarcocheilichthys. Present study provides useful data to population genetics and conservation biology of Sarcocheilichthys fishes
Visible-extended mid-infrared wide spectrum detector based on InAs/GaSb type-â…ˇ superlattices (T2SL)
The authors report an innovative design of wide spectrum detector that can detect visible and mid-infrared spectrum, from 0.4 to 5 μm, simultaneously. The detector is designed with microstructure of various types of photon traps fabricated on mid-infrared InAs/GaSb type-II superlattice materials. Quantum efficiency has been significantly improved due to the action of photon traps which can decrease the reflectivity of the surface of InAs/GaSb type-Ⅱ superlattice down to less than 5%. Under the condition of 77 K and 200 mV bias voltage, the responsivity of the detector is about 0.025–0.45 A/W in the visible wavelength regime of 400–790 nm, more than 0.3 A/W in spectrum of 800–2000 nm, respectively. Through the optimized photon trap structure, the responsivity of detector is to 1.25 A/W and predominantly improve the quantum efficiency of the detector up to 52.5% at 3 μm.</p