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Recent advances in parametric neuroreceptor mapping with dynamic PET:basic concepts and graphical analyses

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Neuroscience Bulletin 2014年第5期30卷 733-754页

作者： Seongho Seo Su Jin Kim Dong Soo lee jae Sung lee Department of Nuclear Medicine College of Medicine Department of Brain and Cognitive Sciences College of Natural Sciences institute of Radiation Medicine Medical Research Center Institute of Radiation Medicine Medical Research Center Department of Molecular Medicine and Biopharmaceutical Sciences Graduate School of Convergence Science and Technology Department of Biomedical Sciences College of Medicine Seoul National University

Tracer kinetic modeling in dynamic positron emission tomography （PET） has been widely used to investigate the characteristic distribution patterns or dysfunctions of neuroreceptors in brain diseases. Its practical goal has progressed from regional data quantification to parametric mapping that produces images of kinetic-model parameters by fully exploiting the spatiotemporal information in dynamic PET data. Graphical analysis （GA） is a major parametric mapping technique that is independent on any compartmental model configuration, robust to noise, and computationally efficient. In this paper, we provide an overview of recent advances in the parametric mapping of neuroreceptor binding based on GA methods. The associated basic concepts in tracer kinetic modeling are presented, including commonly-used compartment models and major parameters of interest. Technical details of GA approaches for reversible and irreversible radioligands are described, considering both plasma input and reference tissue input models. Their statistical properties are discussed in view of parametric imaging.

关键词： dynamic positron emission tomography graphical analysis neuroreceptor imaging parametric image tracer kinetic modeling

Colored ultrathin hybrid photovoltaics with high quantum efficiency

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Light(Science & Applications) 2014年第1期3卷 36-42页

作者： Kyu-Tae lee jae Yong lee Sungyong Seo L Jay Guo Department of Electrical Engineering and Computer Science The University of MichiganAnn ArborMichigan 48109USA

Most current solar panels are fabricated via complex processes using expensive semiconductor materials,and they are rigid and heavy with a dull,black *** a result of their non-aesthetic appearance and weight,they are primarily installed on rooftops to minimize their negative impact on building *** large surfaces and interiors of modern buildings are not efficiently utilized for potential electric power ***,we introduce dual-function solar cells based on ultrathin dopant-free amorphous silicon embedded in an optical cavity that not only efficiently extract the photogenerated carriers but also display distinctive colors with the desired angle-insensitive ***-energy-harvesting colored signage is ***,a cascaded photovoltaics scheme based on tunable spectrum splitting can be employed to increase power efficiency by absorbing a broader band of light *** study pioneers a new approach to architecturally compatible and decorative thin-film photovoltaics.

关键词： color filters nanocavities organic–inorganic nanostructures photovoltaics spectrum splitting

Seamless handover between unicast and multicast multimedia streams

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Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第10期15卷 929-942页

作者： Mau-Luen THAM Chee-Onn CHOW Yi-han XU Khong Neng choong Cheng Suan lee Department of Electrical Engineering Faculty of Engineering University of Malaya College of Information Science and Technology Nanjing Forestry University Wireless Communication Cluster MIMOS BerhadKuala Lumpur 57000 Malaysia Power-All Networks Jalan AmpangKuala Lumpur 50450 Malaysia

With the deployment of heterogeneous networks, mobile users are expecting ubiquitous connectivity when using applications. For bandwidth-intensive applications such as Internet Protocol Television(IPTV), multimedia contents are typically transmitted using a multicast delivery method due to its bandwidth efficiency. However, not all networks support multicasting. Multicasting alone could lead to service disruption when the users move from a multicast-capable network to a non-multicast network. In this paper, we propose a handover scheme called application layer seamless switching(ALSS) to provide smooth real-time multimedia delivery across unicast and multicast networks. ALSS adopts a soft handover to achieve seamless playback during the handover period. A real-time streaming testbed is implemented to investigate the overall handover performance, especially the overlapping period where both network interfaces are receiving audio and video packets. Both the quality of service(QoS) and objective-mapped quality of experience(QoE) metrics are measured. Experimental results show that the overlapping period takes a minimum of 56 and 4 ms for multicast-to-unicast(M2U) and unicast-to-multicast(U2M) handover, respectively. The measured peak signal-to-noise ratio(PSNR) confirms that the frame-by-frame quality of the streamed video during the handover is at least 33 dB, which is categorized as good based on ITU-T recommendations. The estimated mean opinion score(MOS) in terms of video playback smoothness is also at a satisfactory level.

关键词： Experimental approach Multimedia session continuity Seamless handover Unicast/multicast switching Multimedia streaming

Milk protein-shelled gold nanoparticles with gastrointestinally active absorption for aurotherapy to brain tumor

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Bioactive Materials 2022年第2期7卷 35-48页

作者： Hyung Shik Kim Seung jae lee Dong Yun lee Department of Bioengineering College of Engineeringand BK FOUR Biopharmaceutical Innovation Leader for Education and Research GroupHanyang UniversitySeoul04763Republic of Korea Institute of Nano Science and Technology Hanyang UniversitySeoul04763Republic of Korea

Orally absorbable gold nanoparticles(AuNP)having cancer ablation therapy is strongly demanded to treat glioblastoma multiforme(GBM)for patients with its highest incidence ***,we develop a milk protein lactoferrin-conjugated AuNP for its oral absorption and targeting to the GBM through the interaction between lactoferrin(Lf)and lactoferrin receptor(LfR)that is highly expressed in the intestine,blood-brain barrier and *** stability and long circulation of AuNP,glutathione and polyethylene glycol(PEG)is introduced,which is called to *** Lf-PEG-AuNP are orally administered to orthotopic GBM-bearing mice,11-fold and 8-fold higher concentrations of AuNP are measured in bloodstreams and GBM in the brain,respectively,compared with ***,orally administered Lf-PEG-AuNP exhibit an outstanding temperature rise in GBM by irradiating laser and significantly reduce tumor ***,we suggest that the Lf-PEG-AuNP can fundamentally target GBM in the brain through oral absorption,and that its efficient photothermal therapy is possible.

关键词： intestine absorption gastrointestinal

Uncertainty Assessment of Soil Erosion Model Using Particle Filtering

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Journal of Mountain Science 2015年第4期12卷 828-840页

作者： Yeonsu KIM Giha lee Hyunuk AN jae E YANG International Water Resources Research Institute Chungnam National University Dept.of Construction & Disaster Prevention Eng. Kyungpook National University Dept.of Agricultural & Rural Eng. Chungnam National University Dept.of Biological Environment Kangwon National University

Recent advances in computer with geographic information system(GIS) technologies have allowed modelers to develop physics-based models for modeling soil erosion processes in time and ***, it has been widely recognized that the effect of uncertainties on model predictions may be more significant when modelers apply such models for their own modeling *** of uncertainty involved in modeling include data, model structural, and parameter *** deal with the uncertain parameters of a catchment-scale soil erosion model(CSEM) and assess simulation uncertainties in soil erosion, particle filtering modeling(PF) is introduced in the *** proposed method, CSEM-PF, estimates parameters of non-linear and non-Gaussian systems, such as a physics-based soil erosion model by assimilating observation data such as discharge and sediment discharge sequences at *** provides timevarying feasible parameter sets as well as uncertainty bounds of outputs while traditional automatic calibration techniques result in a time-invariant global optimal parameter ***-PF was applied to a small mountainous catchment of the Yongdamdam in Korea for soil erosion modeling and uncertainty assessment for three historical typhoon ***, the most optimal parameter sets and uncertainty bounds of simulation of both discharge and sediment discharge at each time step of the study events are provided.

关键词： Data assimilation Particle filter Soil erosion modeling Parameter estimation Time variant parameter Mountainous catchment

Autonomous Optimal Coordination Scheme in Protection System of Power Distribution Network by Using Multi-Agent Concept

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Transactions of Tianjin University 2008年第2期14卷 106-111页

作者： lee Seung-jae KIM Tae-Wan lee Gi-Young Next-Generation Power System Technology Center Myongji UniversityYongin449-728KyunggidoKorea

A protection system using a multi-agent concept for power distribution networks is *** digital over current relay(OCR)is developed as an agent by adding its own intelligence,self-tuning and communication *** main advantage of the multi-agent concept is that a group of agents work together to achieve a global goal which is beyond the ability of each individual *** order to cope with frequent changes in the network operation condition and faults,an OCR agent,proposed in this paper,is able to detect a fault or a change in the network and find its optimal parameters for protection in an autonomous manner considering information of the whole network obtained by communication between other *** this kind of coordination and information exchanges,not only a local but also a global protective scheme is *** in a simple distribution network show the effectiveness of the proposed protection system.

关键词： multi-agent system over current relay(OCR) communication protection of distribution network

Univector field method-based multi-agent navigation for pursuit problem in obstacle environments

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Journal of Central South University 2017年第4期24卷 1002-1012页

作者： Le Pham Tuyen Hoang Huu Viet Sang Hyeok An Seung Gwan lee Dong-Han Kim Tae choong Chung Department of Computer Science and Engineering Kyung Hee University Yongin Gyeonggi 446-701 Korea Department of Information Technology Vinh University 182-Le Duan Vinh City Nghe An 461056 Vietnam Humanitas College Kyung Hee University Yongin Gyeonggi 446-701 Korea Department of Electronics and Radio Engineering Kyung Hee University Yongin Gyeonggi 446-701 Korea

The pursuit problem is a well-known problem in computer science. In this problem, a group of predator agents attempt to capture a prey agent in an environment with various obstacle types, partial observation, and an infinite grid-world. Predator agents are applied algorithms that use the univector field method to reach the prey agent, strategies for avoiding obstacles and strategies for cooperation between predator agents. Obstacle avoidance strategies are generalized and presented through strategies called hitting and following boundary(HFB); trapped and following shortest path(TFSP); and predicted and following shortest path(PFSP). In terms of cooperation, cooperation strategies are employed to more quickly reach and capture the prey agent. Experimental results are shown to illustrate the efficiency of the method in the pursuit problem.

关键词： pursuit problem predator agent prey agent univector field method multi-agent systems

Curcumin-induced cell death depends on the level of autophagic flux in A172 and U87MG human glioblastoma cells

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Chinese Journal of Natural Medicines 2020年第2期18卷 114-122页

作者： lee Jong-Eun Yoon Sung Sik lee jae-Wook Moon Eun-Yi Department of Bioscience and Biotechnology Sejong UniversitySeoul 05006Republic of Korea

Glioblastoma is the deadliest neoplasm with the worst 5-year survival rate among all human *** promotes autophagic cell death or blocks the induction of apoptosis in eukaryotic ***,we investigated whether varying levels of autophagic flux in glioblastoma lead to different efficacies of curcumin treatment using U87 MG and A172 human glioblastoma *** number of LC3 puncta,the number of cells with LC3 puncta and the level of LC3 Ⅱ,Atg5 and Atg7 protein were higher in U87 MG cells compared with A172 *** the cells were incubated with curcumin for 24 or 48 h,the percentage of cell death was higher in A172 cells compared with U87 MG *** the level of LC3 was lower,that of curcumin-induced LC3 was higher,in A172 cells than in U87 MG *** relative increases in cell death and LC3-mediated autophagy were greater under serum starvation in A172 cells compared with U87 MG ***-induced A172 cell death was reduced by serum *** both types of cells were transfected with LC3-GFP,the percentage of cell death was higher in A172 cells than that in U87 MG *** together,the data demonstrate that curcumin-mediated tumor cell death is regulated by the basal level of autophagic flux in different glioblastoma *** suggests that prior to the use of various curcumin therapeutics,the level of basal or induced autophagic flux should be carefully examined in tumor cells for the best efficacy.

关键词： Glioblastoma A172 U87MG Autophagic flux Curcumin

Predictive factors for early clinical response in community-onset Escherichia coli urinary tract infection and effects of initial antibiotic treatment on early clinical response

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World Journal of Clinical Cases 2020年第19期8卷 4342-4348页

作者： Young Jun Kim Jeong-Mi lee jae-Hoon lee Department of Internal Medicine Wonkwang University College of MedicineIksan 54538South Korea Department of Public Health Wonkwang University College of MedicineIksan 54538South Korea Department of Internal Medicine and Institute of Wonkwang Medical Science Wonkwang University College of MedicineIksan 54538South Korea

BACKGROUND Urinary tract infection(UTI)is a common *** often requires hospitalization,and severe presentations,including sepsis and other complications,have a mortality rate of 6.7%-8.7%.AIM To evaluate the predictive factors for early clinical response and effects of initial antibiotic therapy on early clinical response in community-onset Escherichia coli(***)urinary tract infections(UTIs).METHODS This retrospective study was conducted at Wonkwang University Hospital in South Korea between January 2011 and December *** patients(aged>18 years)who were diagnosed with community-onset *** UTI were enrolled in this *** A total of 511 hospitalized patients were included.66.1%of the patients had an early clinical *** mean length of hospital stay in patients with an early clinical response were each 4.3 d shorter than in patients without an early clinical *** the multiple regression analysis,initial appropriate antibiotic therapy(OR=2.449,P=0.006),extended-spectrum(3-lactamase(ESBL)-producing ***(OR=2.112,P=0.044),improper use of broad-spectrum antimicrobials(OR=0.411,P=0.006),and a stay in a healthcare facility before admission(OR=0.562,P=0.033)were the factors associated with an early clinical *** broadspectrum antibiotic therapy was not associated with an early clinical *** ESBL producing ***,and the type of residence before hospital admission were the factors associated with an early clinical *** of initial antibiotic therapy was a predictive factor for an early clinical response,but broadspectrum of initial antibiotic therapy did not impact early clinical response.

关键词： Escherichia coli Urinary tract infections Adult Community acquired infections