| 1. |
- Yu, Wenjin, et al.
(författare)
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Deep Learning-Based Classification of Cancer Cell in Leptomeningeal Metastasis on Cytomorphologic Features of Cerebrospinal Fluid
- 2022
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Ingår i: Frontiers in Oncology. - : Frontiers Media SA. - 2234-943X. ; 12, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Background: It is a critical challenge to diagnose leptomeningeal metastasis (LM), given its technical difficulty and the lack of typical symptoms. The existing gold standard of diagnosing LM is to use positive cerebrospinal fluid (CSF) cytology, which consumes significantly more time to classify cells under a microscope.Objective: This study aims to establish a deep learning model to classify cancer cells in CSF, thus facilitating doctors to achieve an accurate and fast diagnosis of LM in an early stage.Method: The cerebrospinal fluid laboratory of Xijing Hospital provides 53,255 cells from 90 LM patients in the research. We used two deep convolutional neural networks (CNN) models to classify cells in the CSF. A five-way cell classification model (CNN1) consists of lymphocytes, monocytes, neutrophils, erythrocytes, and cancer cells. A four-way cancer cell classification model (CNN2) consists of lung cancer cells, gastric cancer cells, breast cancer cells, and pancreatic cancer cells. Here, the CNN models were constructed by Resnet-inception-V2. We evaluated the performance of the proposed models on two external datasets and compared them with the results from 42 doctors of various levels of experience in the human-machine tests. Furthermore, we develop a computer-aided diagnosis (CAD) software to generate cytology diagnosis reports in the research rapidly.Results: With respect to the validation set, the mean average precision (mAP) of CNN1 is over 95% and that of CNN2 is close to 80%. Hence, the proposed deep learning model effectively classifies cells in CSF to facilitate the screening of cancer cells. In the human-machine tests, the accuracy of CNN1 is similar to the results from experts, with higher accuracy than doctors in other levels. Moreover, the overall accuracy of CNN2 is 10% higher than that of experts, with a time consumption of only one-third of that consumed by an expert. Using the CAD software saves 90% working time of cytologists.Conclusion: A deep learning method has been developed to assist the LM diagnosis with high accuracy and low time consumption effectively. Thanks to labeled data and step-by-step training, our proposed method can successfully classify cancer cells in the CSF to assist LM diagnosis early. In addition, this unique research can predict cancer’s primary source of LM, which relies on cytomorphologic features without immunohistochemistry. Our results show that deep learning can be widely used in medical images to classify cerebrospinal fluid cells. For complex cancer classification tasks, the accuracy of the proposed method is significantly higher than that of specialist doctors, and its performance is better than that of junior doctors and interns. The application of CNNs and CAD software may ultimately aid in expediting the diagnosis and overcoming the shortage of experienced cytologists, thereby facilitating earlier treatment and improving the prognosis of LM.
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| 2. |
- Hao, Jiaming, et al.
(författare)
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High performance optical absorber based on a plasmonic metamaterial
- 2010
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 96:25, s. 251104-
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Tidskriftsartikel (refereegranskat)abstract
- High absorption efficiency is particularly desirable at present for various microtechnological applications including microbolometers, photodectors, coherent thermal emitters, and solar cells. Here we report the design, characterization, and experimental demonstration of an ultrathin, wide-angle, subwavelength high performance metamaterial absorber for optical frequencies. Experimental results show that an absorption peak of 88% is achieved at the wavelength of similar to 1.58 mu m, though theoretical results give near perfect absorption. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3442904]
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| 3. |
- Hao, Jiaming, et al.
(författare)
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Manipulate light polarizations by metamaterials : From microwave to optics
- 2008
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Ingår i: PROCEEDINGS OF THE 2008 INTERNATIONAL WORKSHOP ON METAMATERIALS. - NEW YORK : IEEE. ; , s. 89-89
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Konferensbidrag (refereegranskat)abstract
- Recently, artificially designed metamaterials have become of considerable interests, because they exhibit extraordinary optical characteristics that do not exist in nature and promise many potential applications, such as negative refraction, subwavelength imaging, and electromagnetic invisibility cloaking. Although creating metamaterials at the optical frequency range faces numerous technological challenges, such materials with particular properties have been realized gradually based on new device concepts. In this talk, we present our efforts to employ specific metamaterials to manipulate the polarization states of incident lights, in both microwave [1, 2] and optical frequency regimes [3]. Experimental results reveal that the maximum polarization conversion ratio (PGR) value can reach 100% in microwave regime (see left figure below) and 92% in optical frequency (see right figure blow) under certain conditions. Theoretical studies combined with numerical simulations show that the governing physics is dominated by the unique reflection properties of the metamaterials
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| 4. |
- Hao, Jiaming, et al.
(författare)
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Manipulate light polarizations with metamaterials : From microwave to visible
- 2010
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Ingår i: Frontiers of Physics in China. - : Springer Science and Business Media LLC. - 1673-3487 .- 1673-3606. ; 5:3, s. 291-307
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Tidskriftsartikel (refereegranskat)abstract
- Polarization is an important characteristic of electromagnetic (EM) waves, and efficient manipulations over EM wave polarizations are always desirable in practical applications. Here, we review the recent efforts in controlling light polarizations with metamaterials, at frequencies ranged from microwave to visible. We first presented a 4 x 4 version transfer matrix method (TMM) to study the scatterings by an anisotropic metamaterial of EM waves with arbitrary propagating directions and polarizations. With the 4 x 4 TMM, we discovered several amazing polarization manipulation phenomena based on the reflection geometry and proposed corresponding model metamaterial systems to realize such effects. Metamaterial samples were fabricated with the help of finite-difference-time-domain (FDTD) simulations, and experiments were performed to successfully realize these ideas at both microwave and visible frequencies. Efforts in employing metamaterials to manipulate light polarizations based on the transmission geometry are also reviewed.
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| 5. |
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| 6. |
- Hao, Jiaming, et al.
(författare)
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Nearly total absorption of light and heat generation by plasmonic metamaterials
- 2011
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 83:16, s. 165107-
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Tidskriftsartikel (refereegranskat)abstract
- We theoretically and numerically study the absorption effect and the heat generation in plasmonic metamaterials under light radiation at their plasmonic resonance. Three different types of structures, all possessing high-performance absorption for visible lights, are investigated. The main aim of this work is to present an intuitive and original understanding of the high-performance absorption effects. From the macroscopic electromagnetic point of view, the effective-medium approach is used to describe the absorption effects of the plasmonic metamaterials. On the other hand, the field distributions and heat generation effects in such plasmonic nanostructures are investigated, which also provides a satisfactory qualitative description of such absorption behavior based upon the microscopic perspective.
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| 7. |
- Hao, Jiaming, et al.
(författare)
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Optical metamaterial for polarization control
- 2009
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Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 80:2
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Tidskriftsartikel (refereegranskat)abstract
- We present the design, characterization, and modeling of a specific optical metamaterial, and employ it to manipulate the light polarizations at optical frequencies. Experimental results reveal that the maximum polarization conversion efficiency, i.e., the energy portion converted from s to p polarization after reflection, can be as high as 96% at the wavelength of similar to 685 nm. Simulations and analytical results, which are in reasonable agreements with the experimental results, reveal that the underlying physics are governed by the particular electric and magnetic resonances in the optical metamaterial.
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| 8. |
- Jiang, Jiwan, et al.
(författare)
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A Personalized Human Drivers' Risk Sensitive Characteristics Depicting Stochastic Optimal Control Algorithm for Adaptive Cruise Control
- 2020
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Ingår i: IEEE Access. - 2169-3536 .- 2169-3536. ; 8, s. 145056-145066
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a personalized stochastic optimal adaptive cruise control (ACC) algorithm for automated vehicles (AVs) incorporating human drivers' risk-sensitivity under system and measurement uncertainties. The proposed controller is designed as a linear exponential-of-quadratic Gaussian (LEQG) problem, which utilizes the stochastic optimal control mechanism to feedback the deviation from the design car-following target. With the risk-sensitive parameter embedded in LEQG, the proposed method has the capability to characterize risk preference heterogeneity of each AV against uncertainties according to each human drivers' preference. Further, the established control theory can achieve both expensive control mode and non-expensive control mode via changing the weighting matrix of the cost function in LEQG to reveal different treatments on input. Simulation tests validate the proposed approach can characterize different driving behaviors and its effectiveness in terms of reducing the deviation from equilibrium state. The ability to produce different trajectories and generate smooth control of the proposed algorithm is also verified.
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| 9. |
- Li, Meng, et al.
(författare)
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A cooperative energy efficient truck platoon lane-changing model preventing platoon decoupling in a mixed traffic environment
- 2024
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Ingår i: Journal of Intelligent Transportation Systems. - : Informa UK Limited. - 1547-2442 .- 1547-2450. ; 28:2, s. 174-188
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Tidskriftsartikel (refereegranskat)abstract
- Truck platooning has gained increasing attention due to the benefits in energy and operation efficiency in freight transportation. One significant challenge for deploying truck platoons is the safe and efficient interaction with surrounding traffic, especially at freeway discontinuities where mandatory lane changes usually lead to the decoupling of truck platoons. This study proposes a cooperative truck platoon lane-changing model (CTPLC) to prevent the decoupling of truck platoons in a mixed traffic environment. Specifically, a two-step control strategy is presented, where vehicles in the target lane firstly cooperatively adjust speeds to create an appropriate gap for a truck platoon, and then trucks within the truck platoon conduct lane change sequentially. The cooperative speed profiles are generated by solving an optimization problem considering the lane-changing influence and energy consumption. Based on that, a two-dimensional nonlinear model predictive control (MPC) algorithm is employed to generate vehicular acceleration and steering angle for each truck. A series of numerical simulation experiments were conducted to validate the proposed strategy. As shown by the results, our proposed method truck platoon could conduct a lane change in a traffic-efficient and safe manner, and meanwhile, our method was more energy-efficient than a benchmark strategy.
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| 10. |
- Rasmussen, Michel, et al.
(författare)
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Enhanced cGMP Interactor Rap Guanine Exchange Factor 4 (EPAC2) Expression and Activity in Degenerating Photoreceptors: : A Neuroprotective Response?
- 2022
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1422-0067. ; 23:9
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Tidskriftsartikel (refereegranskat)abstract
- The disease retinitis pigmentosa (RP) leads to photoreceptor degeneration by a yet undefined mechanism(s). In several RP mouse models (i.e., rd mice), a high cyclic GMP (cGMP) level within photoreceptors is detected, suggesting that cGMP plays a role in degeneration. The rap guanine exchange factor 4 (EPAC2) is activated by cyclic AMP (cAMP) and is an accepted cGMP-interacting protein. It is unclear whether and how cGMP interacts with EPAC2 in degenerating photoreceptors; we therefore investigated EPAC2 expression and interactions with cGMP and cAMP in retinas of the rd1 and rd10 models for retinal degeneration. EPAC2 expression in the photoreceptor layer increased significantly during rd1 and rd10 degeneration, and an increase in EPAC2 interactions with cGMP but not cAMP in the rd1 was also seen via a proximity ligation assay on histological sections. Retinal explant cultures revealed that pharmacological inhibition of the EPAC2 activity reduced the photoreceptor layer thickness in the rd10 retina, suggesting that EPAC2 inhibition promotes degeneration. Taken together, our results support the hypothesis that high degeneration-related cGMP leads to increased EPAC2 and cGMP interactions, inhibiting EPAC2. By inference, EPAC2 could have neuroprotective capacities that may be exploited in the future.
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