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Imaging features of solid pseudopapillary tumor of the pancreas on multi-detector row computed tomography

World Journal of Gastroenterology 2009年第7期15卷 829-835页

作者： Deng-Bin Wang Qing-Bing Wang wei-min chai Ke-min Chen Xia-Xing Deng Department of Radiology Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai 200025 China Department of General Surgery Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai 200025 China

AIM： To retrospectively analyze the imaging features of solid-pseudopapillary tumors （SPTs） of the pancreas on multi-detector row computed tomography （MDCT） and define the imaging findings suggestive of malignant potential. METHODS： A total of 24 consecutive cases with surgically and pathologically confirmed SPTs of the pancreas underwent preoperative abdominal MDCT studies in our hospital. All axial CT images, CT angiographic images, and coronally and sagittally reformed images were obtained. The images were retrospectively reviewed at interactive picture archiving and communication system workstations. RESULTS： Of the 24 cases of SPTs, 11 cases （45.8%） occurred in the pancreatic head and seven （29.1%） in the tail. Eighteen were pathologically diagnosed as benign and six as malignant. MDCT diagnosis of SPTs was well correlated with the surgical and pathological results （Kappa = 0.6, P 〈 0.05）. The size of SPTs ranged from 3 to 15 cm （mean, 5.8 cm）. When the size of the tumor was greater than 6 cm （including 6 cm）, the possibilities of vascular （8 vs 1） and capsular invasion （9 vs 0） increased significantly （P 〈 0.05）.Two pathologically benign cases with vascular invasion and disrupted capsule on MDCT presented with local recurrence and hepatic metastases during follow-up about 1 year after the resection of the primary tumors. CONCLUSION： Vascular and capsular invasion with superimposed spread into the adjacent pancreatic parenchyrna and nearby structures in SPTs of the pancreas can be accurately revealed by MDCT preoperatively. These imaging findings are predictive of the malignant potential associated with the aggressive behavior of the tumor, even in the pathologically benign cases.

关键词： Solid pseudopapillary tumor Pancreas Multi-detector row computed tomography Malignantpotential Aggressive behaviors

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FEASIBILITY OF DIAGNOSING AND STAGING LIVER FIBROSIS WITH DIFFUSION weiGHTED IMAGING

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Chinese Medical Sciences Journal 2008年第3期23卷 183-186页

作者： Nai-yi Zhu Ke-min Chen wei-min chai wei-xia Li Lian-jun Du Department of Radiology Ruijin Hospital School of Medicine Shanghai Jiaotong University Shanghai 200025

Objective To assess the clinical feasibility of diagnosing and staging liver fibrosis by apparent diffusion coefficient (ADC). Methods Totally, 43 patients (mean age 29.3 years) with chronic hepatitis by liver biopsy and 7 healthy controls (mean age 39.9 years) underwent liver diffusion weighted imaging (DWI) with four b values: 0, 200, 500, and 1000 s/mm2 respectively. The liver fibrosis was staged according to Ishak fibrosis stage. The ADC value of liver fibrosis patients and healthy controls was compared. The correlation of ADC value and liver fibrosis staging was analyzed. Result The histological staging showed 8 stage 1 patients, 10 stage 2 patients, 6 stage 3 patients, 9 stage 4 patients, 8 stage 5 patients and 2 stage 6 patients. The mean ADC value of liver fibrosis patients was significantly lower than that of healthy controls except for stage 1 group (P < 0.05). There was a negative correlation between liver fibrosis staging and ADC value (r = -0.697 with b=500 s/mm2, P < 0.01). Receiver operating characteristic (ROC) curve of ADC value of advanced liver fibrosis (Ishak stage F3 and higher) showed that area under curve = 0.913, 0.825, and 0.794 with b = 500, 1000, and 200 s/mm2, respectively (95% confidence interval: 83.6%-99.0%, 70.7%-94.3%, 66.5%- 92.4%; P < 0.05). When b value was 500 s/mm2, the sensitivity (84%) and specificity (80%) of DWI for diagnosis of advanced liver fibrosis were the highest. Conclusion DWI is proved to be a useful clinical tool in the quantitative evaluation of liver fibrosis and in the prediction of the process of liver fibrosis with the recommendable b value (500 s/mm2).

关键词： diffusion weighted imaging apparent diffusion coefficient liver fibrosis

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Is the Cape Stone Forest in Shantou City formed by wave erosion? A comparison of the pedestal rocks on the coasts and the mountains of Queshi in eastern Guangdong, China

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Journal of Mountain Science 2024年第5期21卷 1447-1463页

作者： CHEN min WANG wei School of Geography South China Normal UniversityGuangzhou 510631China

Cape Stone Forest is a group of granite rock pillars(pedestal rocks) towering over Shilin Lake, on the southern shore of Shantou Bay in eastern Guangdong, China. The rock pillars were previously identified as sea stacks because they have marine notch-like concave sidewalls at their base, and more importantly, the lake is immediately adjacent to the bay, which is exposed to the open sea. However, rock pillars similar in shape and size can also be found at the top of Queshi Mountain, which is only about 300 meters northwest of the lake and about 85 meters above sea level. Therefore, the marine origin of Cape Stone Forest is seriously questioned. In this study, 3D imagery and drone technology were used to collect data in the investigations without direct manual measurements in the water or on the mountain. It shows that the concave sidewalls of the rock pillars in the lake and on the mountains occur at different heights and are exposed to different directions, while a natural sea stack on Mayu Island at the mouth of Shantou Bay has a horizontal notch parallel to the sea level, although the granite rock of the sea stack is the same as that of the lake and the mountains. The eastern side of the island, where the sea stack is located, is exposed to the open sea but blocks large waves for the rock pillars in the lake. Therefore, the origin of Cape Stone Forest cannot be explained by wave-based mechanisms. The only satisfactory explanation that takes into account all the field evidence is that the narrow rock pillars of the lake and mountain were formed by chemical weathering that penetrated closely the spaced joints of the granite rock, and the notch-like concave sidewalls were formed by more effective chemical weathering at the base of the pillars.

关键词： Pedestal rock Granite Closely spaced joints Wave erosion Chemical weathering

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Multi-instance partial-label learning: towards exploiting dual inexact supervision

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Science China(Information Sciences) 2024年第3期67卷 48-61页

作者： wei TANG weijia ZHANG min-Ling ZHANG School of Computer Science and Engineering Southeast University Key Laboratory of Computer Network and Information Integration (Southeast University) Ministry of Education School of Information and Physical Sciences The University of Newcastle

Weakly supervised machine learning algorithms are able to learn from ambiguous samples or labels, e.g., multi-instance learning or partial-label learning. However, in some real-world tasks, each training sample is associated with not only multiple instances but also a candidate label set that contains one groundtruth label and some false positive labels. Specifically, at least one instance pertains to the ground-truth label while no instance belongs to the false positive labels. In this paper, we formalize such problems as multi-instance partial-label learning(MIPL). Existing multi-instance learning algorithms and partial-label learning algorithms are suboptimal for solving MIPL problems since the former fails to disambiguate a candidate label set, and the latter cannot handle a multi-instance bag. To address these issues, a tailored algorithm named MIPLGP, i.e., multi-instance partial-label learning with Gaussian processes, is *** first assigns each instance with a candidate label set in an augmented label space, then transforms the candidate label set into a logarithmic space to yield the disambiguated and continuous labels via an exclusive disambiguation strategy, and last induces a model based on the Gaussian processes. Experimental results on various datasets validate that MIPLGP is superior to well-established multi-instance learning and partial-label learning algorithms for solving MIPL problems.

关键词： machine learning multi-instance partial-label learning multi-instance learning partial-label learning Gaussian processes

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A condition-based maintenance policy for reconfigurable multi-device systems

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Advances in Manufacturing 2024年第2期12卷 252-269页

作者： Shu-Lian Xie Feng Xue wei-min Zhang Jia-wei Zhu School of Mechanical Engineering Tongji UniversityShanghai201804People’s Republic of China

The exploration of component states for optimizing maintenance schedules in complex systems has garnered significant interest from ***,current literature usually overlooks the critical aspects of system flexibility and *** implementation of system reconfiguration can effectively mitigate system downtime and enhance production *** study proposes a dynamic condition-based maintenance policy considering reconfiguration for reconfigurable systems.A double-layer decision rule was constructed for the devices and *** achieve the best overall maintenance effect of the system,the remaining useful life probability distribution and recommended maintenance time of each device were used to optimize the concurrent maintenance time window of the devices and determine whether to reconfigure them.A comprehensive maintenance efficiency index was introduced that simultaneously considered the maintenance cost rate,reliability,and availability of the system to characterize the overall maintenance *** reconfiguration cost was included in the maintenance *** proposed policy was tested through numerical experiments and compared with different-level *** results show that the proposed policy can significantly reduce the downtime and maintenance costs and improve the overall system reliability and availability.

关键词： Condition-based maintenance(CBM) Reconfigurable system Remaining useful life Maintenance cost System reliability

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Photochemical synthesis and group transfer reactions of azoxy compounds

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Chinese Chemical Letters 2024年第8期35卷 1-2页

作者： Mei Peng wei-min He School of Pharmaceutical Science Hengyang Medical SchoolUniversity of South ChinaHengyang 421001China

Azoxy compounds are extensively utilized in various fields,including dyes,polymerization *** high nitrogen and oxygen content make them ideal for use as energy storage materials[1-4].Additionally,azoxy functional groups are found in various natural *** 1949,chemists successfully isolated natural congener of azoxy compounds from cycads,marking a significant ***,azoxy compounds were also discovered in mushrooms,sponges,and soil-dwelling bacteria,showing promising pharmaceutical activity,including antimicrobial,antifungal or antibacterial agents(Scheme 1)[5].

关键词： compounds synthesis sponge

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Moderate Deviations for Parameter Estimation in the Fractional Ornstein–Uhlenbeck Processes with Periodic Mean

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Acta Mathematica Sinica,English Series 2024年第5期40卷 1308-1324页

作者： Hui JIANG Shi min LI wei Gang WANG School of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 210016P.R.China The People's Bank of China Operations Ofice of Nanjing Branch Nanjing 210016P.R.China School of Statistics and Mathematics Zhejiang Gongshang UniversityHangzhou 310018P.R.China

In this paper,we study the asymptotic properties for the drift parameter estimators in the fractional Ornstein-Uhlenbeck process with periodic mean function and long range *** Cremér-type moderate deviations,as well ... 详细信息

关键词： Cramér-type moderate deviation fractional Ornstein-Uhlenbeck process parameter estimation multiple Wiener-Ito integrals

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Photoinduced bismuth vanadate-catalyzed C(sp^(2))-H functionalization

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Chinese Chemical Letters 2024年第3期35卷 1-2页

作者： Rong-Nan Yi wei-min He Key Laboratory of Food&Environment&Drug Monitoring and Testing of Universities in Hunan Province Hunan Police AcademyChangsha 410138China School of Chemistry and Chemical Engineering University of South ChinaHengyang 421001China

Visible light-induced organic reactions have gained much attention in recent years due to their mild conditions and high efficiency[1,2].In this context,many efficient photocatalysts including transition metal complex... 详细信息

关键词： bismuth catalyzed gained

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Heterophase junction engineering-induced Co spin-state modulation of CoSe_(2) for large-current hydrogen evolution reaction

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Rare Metals 2024年第6期43卷 2660-2670页

作者： Bao-chai Xu Ya-Ping Miao min-Qin Mao Dong-Lian Li Song Xie wei-Hong Jin Shu Xiao Jing Wen Zaenab Abd-Allah Zhi-Tian Liu Xiang Peng Paul K.Chu Hubei Key Laboratory of Plasma Chemistry and Advanced Materials School of Materials Science and EngineeringWuhan Institute of TechnologyWuhan 430205China School of Textile Science and Engineering Xi'an Polytechnic UniversityXi'an 710048China Institute of Advanced Wear and Corrosion Resistant and Functional Materials Jinan UniversityGuangzhou 510632China Institute of Safety Science and Engineering South China University of TechnologyGuangzhou 510641China Department of Engineering Manchester Metropolitan UniversityManchester M156BHUK Department of Physics Department of Materials Science and Engineeringand Department of Biomedical EngineeringCity University of Hong KongHong Kong 999077China

Efficient electrocatalysts are vital to large-current hydrogen production in commercial water splitting for green energy ***,a novel heterophase engineering strategy is described to produce polymorphic CoSe_(2)*** composition of the electrocatalysts consisting of both cubic CoSe_(2)(c-CoSe_(2))and orthorhombic CoSe_(2)(o-CoSe_(2))phases can be controlled *** results demonstrate that junction-induced spin-state modulation of Co atoms enhances the adsorption of intermediates and accelerates charge transfer resulting in superior large-current hydrogen evolution reaction(HER)***,the CoSe_(2)based heterophase catalyst with the optimal c-CoSe_(2)content requires an overpotential of merely 240 mV to achieve 1,000 mA·cm^(-2)as well as a Tafel slope of 50.4 mV·dec^(-1).Furthermore,the electrocatalyst can maintain a large current density of 1,500 mA·cm^(-2)for over 320 h without *** results reveal the advantages and potential of heterophase junction engineering pertaining to design and fabrication of low-cost transition metal catalysts for large-current water splitting.

关键词： Heterophase junction Spin-state Hydrogen evolution reaction Large current electrochemical hydrogen production Water splitting

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Hybrid Dynamic Variables-Dependent Event-Triggered Fuzzy Model Predictive Control

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IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 723-733页

作者： Xiongbo Wan Chaoling Zhang Fan wei Chuan-Ke Zhang min Wu IEEE the School of Automation China University of Geosciencesthe Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systemsand the Engineering Research Center of Intelligent Technology for Geo-ExplorationMinistry of EducationWuhan 430074China

This article focuses on dynamic event-triggered mechanism(DETM)-based model predictive control(MPC) for T-S fuzzy systems.A hybrid dynamic variables-dependent DETM is carefully devised,which includes a multiplicative dynamic variable and an additive dynamic *** addressed DETM-based fuzzy MPC issue is described as a “min-max” optimization problem(OP).To facilitate the co-design of the MPC controller and the weighting matrix of the DETM,an auxiliary OP is proposed based on a new Lyapunov function and a new robust positive invariant(RPI) set that contain the membership functions and the hybrid dynamic variables.A dynamic event-triggered fuzzy MPC algorithm is developed accordingly,whose recursive feasibility is analysed by employing the RPI *** the designed controller,the involved fuzzy system is ensured to be asymptotically *** examples show that the new DETM and DETM-based MPC algorithm have the advantages of reducing resource consumption while yielding the anticipated performance.

关键词： Dynamic event-triggered mechanism(DETM) hybrid dynamic variables model predictive control(MPC) robust positive invariant(RPI)set T-S fuzzy systems

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