• 제목/요약/키워드: P2P networks

검색결과 424건 처리시간 0.025초

Deep Learning-Based Algorithm for the Detection and Characterization of MRI Safety of Cardiac Implantable Electronic Devices on Chest Radiographs

  • Ue-Hwan Kim;Moon Young Kim;Eun-Ah Park;Whal Lee;Woo-Hyun Lim;Hack-Lyoung Kim;Sohee Oh;Kwang Nam Jin
    • Korean Journal of Radiology
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    • 제22권11호
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    • pp.1918-1928
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    • 2021
  • Objective: With the recent development of various MRI-conditional cardiac implantable electronic devices (CIEDs), the accurate identification and characterization of CIEDs have become critical when performing MRI in patients with CIEDs. We aimed to develop and evaluate a deep learning-based algorithm (DLA) that performs the detection and characterization of parameters, including MRI safety, of CIEDs on chest radiograph (CR) in a single step and compare its performance with other related algorithms that were recently developed. Materials and Methods: We developed a DLA (X-ray CIED identification [XCID]) using 9912 CRs of 958 patients with 968 CIEDs comprising 26 model groups from 4 manufacturers obtained between 2014 and 2019 from one hospital. The performance of XCID was tested with an external dataset consisting of 2122 CRs obtained from a different hospital and compared with the performance of two other related algorithms recently reported, including PacemakerID (PID) and Pacemaker identification with neural networks (PPMnn). Results: The overall accuracies of XCID for the manufacturer classification, model group identification, and MRI safety characterization using the internal test dataset were 99.7% (992/995), 97.2% (967/995), and 98.9% (984/995), respectively. These were 95.8% (2033/2122), 85.4% (1813/2122), and 92.2% (1956/2122), respectively, with the external test dataset. In the comparative study, the accuracy for the manufacturer classification was 95.0% (152/160) for XCID and 91.3% for PPMnn (146/160), which was significantly higher than that for PID (80.0%,128/160; p < 0.001 for both). XCID demonstrated a higher accuracy (88.1%; 141/160) than PPMnn (80.0%; 128/160) in identifying model groups (p < 0.001). Conclusion: The remarkable and consistent performance of XCID suggests its applicability for detection, manufacturer and model identification, as well as MRI safety characterization of CIED on CRs. Further studies are warranted to guarantee the safe use of XCID in clinical practice.

fMRI를 이용한 망간 노출 용접공의 운동수행에 따른 뇌 활성도 평가 (Cerebral Activity by Motor Task in Welders Exposed to Manganese through fMRI)

  • 최재호;장봉기;이종화;홍은주;이명주;지동하
    • 한국환경보건학회지
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    • 제37권2호
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    • pp.102-112
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    • 2011
  • Objectives: The purpose of this study is to analyze the effects of chronic exposure by welders to manganese (Mn) through an analysis of the degree of brain activity in different activities such as cognition and motor activities using the neuroimaging technique of functional magnetic resonance imaging (fMRI). The neurotoxic effect that Mn has on the brain was examined as well as changes in the neuro-network in motor areas, and the usefulness of fMRI was evaluated as a tool to determine changes in brain function from occupational exposure to Mn. Methods: A survey was carried out from July 2010 to October 2010 targeting by means of a questionnaire 160 workers from the shipbuilding and other manufacturing industries. Among them, 14 welders with more than ten years of job-related exposure to Mn were recruited on a voluntary basis as an exposure group, and 13 workers from other manufacturing industries with corresponding gender and age were recruited as a control group. A questionnaire survey, a blood test, and an fMRI test were carried out with the study group as target. Results: Of 27 fMRI targets, blood Mn concentration of the exposure group was significantly higher than that of the control group (p<0.001), and Pallidal Index (PI) of the welder group was also significantly higher than that of the control group (p<0.001). As a result of the survey, the score of the exposure group in self-awareness of abnormal nerve symptoms and abnormal musculoskeletal symptoms was higher than those of the control group, and there was a significant difference between the two groups (p<0.05, respectively). In the correlation between PI and the results of blood tests, the correlation coefficient with blood Mn concentration was 0.893, revealing a significant amount of correlation (p<0.001). As for brain activity area within the control group, the right and the left areas of the superior frontal cortex showed significant activity, and the right area of superior parietal cortex, the left area of occipital cortex and cerebellum showed significant activity. Unlike the control group, the exposure group showed significant activity selectively on the right area of premotor cortex, at the center of supplementary motor area, and on the left side of superior temporal cortex. In the comparison of brain activity areas between the two groups, the exposure group showed a significantly higher activation state than did the control group in such areas as the right and the left superior parietal cortex, superior temporal cortex, and cerebellum including superior frontal cortex and the right area of premotor cortex. However, in nowhere did the control group show a more activated area than did the exposure group. Conclusions: Chronic exposure to Mn increased brain activity during implementation of hand motor tasks. In an identical task, activation increased in the premotor cortex, superior temporal cortex, and supplementary motor area. It was also discovered that brain activity increase in the frontal area and occipital area was more pronounced in the exposure group than in the control group. This result suggests that chronic exposure to Mn in the work environment affects brain activation neuro-networks.

Expression of NAC transcription factor is altered under intermittent drought stress and re-watered conditions in Hevea brasiliensis

  • Luke, Lisha P.;Sathik, M.B. Mohamed;Thomas, Molly;Kuruvilla, Linu;Sumesh, K.V.
    • Journal of Plant Biotechnology
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    • 제44권2호
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    • pp.142-148
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    • 2017
  • Drought stress is one of the important factors that restrict the expansion of Hevea brasiliensis cultivation to non-traditional regions experiencing extreme weather conditions. Plants respond to drought stress by triggering expression of several drought responsive genes including transcription factors which in turn trigger expression of various downstream signalling pathways and adaptive networks. Expression of such drought responsive genes may revert back to their original level upon re-watering. However, no reports are available on such phenomenon in Hevea and hence, this study was initiated. For this purpose, NAC transcription factor (NAC tf) was chosen as candidate gene. Its expression levels were monitored under intermittent drought as well as irrigated conditions in two clones (RRII 105 and RRIM 600) of H. brasiliensis with contrasting tolerance level. Copy number of NAC tf was found similar in both the clones. Expression of NAC tf was found highly up-regulated in RRIM 600 (a relatively drought tolerant clone) than in RRII 105 (a relatively drought susceptible clone) throughout the drought incidences which upon re-watering, reached back to its original levels in both the clones. The study indicated the existence of an association between expression of NAC tf and drought tolerance trait exhibited by the tolerant clone RRIM 600. The study also proves the influence of drought and re-watering on the leaf photosynthesis and expression of NAC tf in H. brasiliensis.

A 900 MHz Zero-IF RF Transceiver for IEEE 802.15.4g SUN OFDM Systems

  • Kim, Changwan;Lee, Seungsik;Choi, Sangsung
    • ETRI Journal
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    • 제36권3호
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    • pp.352-360
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    • 2014
  • This paper presents a 900 MHz zero-IF RF transceiver for IEEE 802.15.4g Smart Utility Networks OFDM systems. The proposed RF transceiver comprises an RF front end, a Tx baseband analog circuit, an Rx baseband analog circuit, and a ${\Delta}{\Sigma}$ fractional-N frequency synthesizer. In the RF front end, re-use of a matching network reduces the chip size of the RF transceiver. Since a T/Rx switch is implemented only at the input of the low noise amplifier, the driver amplifier can deliver its output power to an antenna without any signal loss; thus, leading to a low dc power consumption. The proposed current-driven passive mixer in Rx and voltage-mode passive mixer in Tx can mitigate the IQ crosstalk problem, while maintaining 50% duty-cycle in local oscillator clocks. The overall Rx-baseband circuits can provide a voltage gain of 70 dB with a 1 dB gain control step. The proposed RF transceiver is implemented in a $0.18{\mu}$ CMOS technology and consumes 37 mA in Tx mode and 38 mA in Rx mode from a 1.8 V supply voltage. The fabricated chip shows a Tx average power of -2 dBm, a sensitivity level of -103 dBm at 100 Kbps with PER < 1%, an Rx input $P_{1dB}$ of -11 dBm, and an Rx input IP3 of -2.3 dBm.

Tight junction protein 1 is regulated by transforming growth factor-β and contributes to cell motility in NSCLC cells

  • Lee, So Hee;Paek, A Rome;Yoon, Kyungsil;Kim, Seok Hyun;Lee, Soo Young;You, Hye Jin
    • BMB Reports
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    • 제48권2호
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    • pp.115-120
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    • 2015
  • Tight junction protein 1 (TJP1), a component of tight junction, has been reported to play a role in protein networks as an adaptor protein, and TJP1 expression is altered during tumor development. Here, we found that TJP1 expression was increased at the RNA and protein levels in TGF-${\beta}$-stimulated lung cancer cells, A549. SB431542, a type-I TGF-${\beta}$ receptor inhibitor, as well as SB203580, a p38 kinase inhibitor, significantly abrogated the effect of TGF-${\beta}$ on TJP1 expression. Diphenyleneiodonium, an NADPH oxidase inhibitor, also attenuated TJP1 expression in response to TGF-${\beta}$ in lung cancer cells. When TJP1 expression was reduced by shRNA lentiviral particles in A549 cells (A549-sh TJP1), wound healing was much lower than in cells infected with control viral particles. Taken together, these data suggest that TGF-${\beta}$ enhances TJP1 expression, which may play a role beyond structural support in tight junctions during cancer development.

Influence of the Francis Turbine location under vortex rope excitation on the Hydraulic System Stability

  • Alligne, S.;Nicolet, C.;Allenbach, P.;Kawkabani, B.;Simond, J.J.;Avellan, F.
    • International Journal of Fluid Machinery and Systems
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    • 제2권4호
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    • pp.286-294
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    • 2009
  • Hydroelectric power plants are known for their ability to cover variations of the consumption in electrical power networks. In order to follow this changing demand, hydraulic machines are subject to off-design operation. In that case, the swirling flow leaving the runner of a Francis turbine may act under given conditions as an excitation source for the whole hydraulic system. In high load operating conditions, vortex rope behaves as an internal energy source which leads to the self excitation of the system. The aim of this paper is to identify the influence of the full load excitation source location with respect to the eigenmodes shapes on the system stability. For this, a new eigenanalysis tool, based on eigenvalues and eigenvectors computation of the nonlinear set of differential equations in SIMSEN, has been developed. First the modal analysis method and linearization of the set of the nonlinear differential equations are fully described. Then, nonlinear hydro-acoustic models of hydraulic components based on electrical equivalent schemes are presented and linearized. Finally, a hydro-acoustic SIMSEN model of a simple hydraulic power plant, is used to apply the modal analysis and to show the influence of the turbine location on system stability. Through this case study, it brings out that modeling of the pipe viscoelastic damping is decisive to find out stability limits and unstable eigenfrequencies.

주의력결핍과잉행동장애 아동에 대한 초등교사의 지도실태와 지식 (Teaching Status and Knowledge of Elementary School Teachers of Children with Attention Deficit Hyperactivity Disorder)

  • 강경림;김영혜;양영옥
    • Child Health Nursing Research
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    • 제17권2호
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    • pp.136-144
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    • 2011
  • Purpose: The purpose of this study was to analyze teaching status and knowledge about children with Attention Deficit Hyperactivity Disorder (ADHD) in elementary school teachers. Methods: The participants of this study were 204 elementary school teachers in Busan. From July to September 2010, the researchers collected data by using self-report questionnaires consisted of questions about their teachers' characteristics and teaching status and KADDS (36 items) developed by Sciutto, Terjesen and Frank. Frequency, percentage, arithmetic mean, standard deviation, t-test and ANOVA were used to analyze the data using SPSS WIN 16.0 program. Results: Less than 50% of the participants had previous education on ADHD. According to this experience, there were significant differences in participants' knowledge about children with ADHD (t=4.703, p<.001). For the 36 items, participants had an average of $19.19{\pm}4.58$ points out of a possible 36. Moreover, lack of knowledge about teaching children with ADHD and communication problems with the parents of these children were considered to be the most disturbing factors. Conclusion: These results suggest that networks among teachers, parents and medical care professionals should be established. The results also indicate that educational programs for elementary school teachers should be developed in order to identify and teach children with ADHD appropriately.

The Kwinana Shoreline Fumigation Experiment in Western Australia, Australia

  • Yoon, I.H.;Sawford, B.L;Manins, P.C.
    • 한국환경과학회:학술대회논문집
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    • 한국환경과학회 1996년도 봄 학술발표회 초록집
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    • pp.22-22
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    • 1996
  • ;The Kwinana Shoreline Fumigation Experiment(KSFE) took place in Fremantle, WA, Australia between 23 January and 8 February, 1995. All measurement systems performed to expectation. The CSIRO DAR(Division of Atmospheric Research) LIDAR measured plume sections from near the Kwinana Power Station(KPS) stacks to up to about 5 km downstream. It also measured boundary layer aerosols and the structure of the boundary layer on some occasions. Both stages A and C of KPS were used as tracers at different times. Radiosonde and double theodolite sounding systems measured temperature, humidity, air pressure and wind structure at the coast(Woodman Point) and at the inland(ALCOA residue dump) site at intervals of roughly two hours. These were supplemented by mid afternoon soundings(radiosonde and single theodolite) by Department of Environmental Protection(DEP) at Swanbourne. The Flinders aircraft measured wind, turbulence and temperature structure of the atmospheric boundary layer, concentrations of $C0_2,\;0_3,\;S0_2\;and\;NO_x$ in the smoke plumes and surface radiation over both land and sea. CSIRO DCET(Division of Coal and Energy Technology) vehicle successfully interceptde many smoke plumes and using a range of tracers will be able to identify the various sources much of the time. Routine data from the DEP and Kwinana Industrial Council(KIC) air quality monitoring networks were also automatically logged. Murdoch University measured surface heat flux at Hope Valldy monitoring station and also at Wattleup monitoring station for the last five days. The heart of the LIDAR system is a Neodymium-doped Yttrium-aluminumgarnet(Nd:Y AG) laser operating at a fundamental wavelength of 1064 nm, with harmonics fo 532 nm and 355 nm. A small fraction of the laser beam is scattered back to the LIDAR, collected by a telescope and detedted by a photomultiplier tube. The intensity of the signal as a function of time is a measure of the particle concentration as a function of distance along the line of the laser shot. The results of nine days special field observations are summarized in detail.etail.

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Antibacterial activity of florfenicol composite nanogels against Staphylococcus aureus small colony variants

  • Liu, Jinhuan;Ju, Mujie;Wu, Yifei;Leng, Nannan;Algharib, Samah Attia;Luo, Wanhe
    • Journal of Veterinary Science
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    • 제23권5호
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    • pp.78.1-78.13
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    • 2022
  • Background: Florfenicol might be ineffective for treating Staphylococcus aureus small colony variants (SCVs) mastitis. Objectives: In this study, florfenicol-loaded chitosan (CS)-sodium tripolyphosphate (TPP) composite nanogels were prepared to allow targeted delivery to SCV infected sites. Methods: The formulation screening, the characteristics, in vitro release, antibacterial activity, therapeutic efficacy, and biosafety of the florfenicol composite nanogels were studied. Results: The optimized formulation was obtained when the CS and TPP were 10 and 5 mg/mL, respectively. The encapsulation efficiency, loading capacity, size, polydispersity index, and zeta potential of the optimized florfenicol composite nanogels were 87.3% ± 2.7%, 5.8% ± 1.4%, 280.3 ± 1.5 nm, 0.15 ± 0.03, and 36.3 ± 1.4 mv, respectively. Optical and scanning electron microscopy showed that spherical particles with a relatively uniform distribution and drugs might be incorporated in cross-linked polymeric networks. The in vitro release study showed that the florfenicol composite nanogels exhibited a biphasic pattern with the sustained release of 72.2% ± 1.8% at 48 h in pH 5.5 phosphate-buffered saline. The minimal inhibitory concentrations of commercial florfenicol solution and florfenicol composite nanogels against SCVs were 1 and 0.25 ㎍/mL, respectively. The time-killing curves and live-dead bacterial staining showed that the florfenicol composite nanogels were concentration-dependent. Furthermore, the florfenicol composite nanogels displayed good therapeutic efficacy against SCVs mastitis. Biological safety studies showed that the florfenicol composite nanogels might be a biocompatible preparation because of their non-toxic effects on the renal tissue and liver. Conclusions: Florfenicol composite nanogels might improve the treatment of SCV infections.

연구소기업 네트워크의 ERGM 분석 연구: 대덕연구개발특구를 중심으로 (A Study on the ERGM on Innopolis Start-ups Networks: Focusing on Daedeok Innopolis)

  • 구장원;임재빈
    • 산업진흥연구
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    • 제9권2호
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    • pp.45-58
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    • 2024
  • 본 연구는 대전 지역에 위치한 연구소기업과 전국에 있는 연구소기업 고객사 간의 사회적 네트워크 구조 특성을 동종 기술 간 지역적 군집화 경향으로 모형화했고, ERGM(Exponential Random Graph Model) 분석 모형 대비 관측값이 95% 신뢰구간 내 포함되었다. 기업 모두 대전 유성구에 위치한 경우, 다른 행정구역에 속한 경우보다 연결 확률이 약 13배 높았을 뿐만 아니라 동종 기술을 가진 기업 간에는 구색성 및 동질성 값이 부의 값(0.1904)으로 활발한 연결 경향을 보였으며, 특히 6대 기술 중 '환경·에너지기술(ET)' 기업 간에 P값이 0.035로 가장 유의하였다. 유성구에 속하지 않은 기업 사이에는 음의 값(-0.0035)을 보이고, 군집 경향도 적었다. 이를 통해 대덕연구개발특구가 입지한 대전광역시 유성구가 혁신클러스터의 중심지 역할을 형성하고 있음을 확인할 수 있었다.