• 제목/요약/키워드: sub-threshold

검색결과 434건 처리시간 0.03초

식·의약 위해 감시체계(K-RISS)의 우선순위 평가를 위한 시계열 구조변화 기반 기준선 설정 모델 개발 (Development of a Baseline Setting Model Based on Time Series Structural Changes for Priority Assessment in the Korea Risk Information Surveillance System (K-RISS))

  • 진현정;허성윤;이헌주;장보윤
    • 한국환경보건학회지
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    • 제50권2호
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    • pp.125-137
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    • 2024
  • Background: The Korea Risk Information Surveillance System (K-RISS) was developed to enable the early detection of food and drug safety-related issues. Its goal is to deliver real-time risk indicators generated from ongoing food and drug risk monitoring. However, the existing K-RISS system suffers under several limitations. Objectives: This study aims to augment K-RISS with more detailed indicators and establish a severity standard that takes into account structural changes in the daily time series of K-RISS values. Methods: First, a Delphi survey was conducted to derive the required weights. Second, a control chart, commonly used in statistical process controls, was utilized to detect outliers and establish caution, attention, and serious levels for K-RISS values. Furthermore, Bai and Perron's method was employed to determine structural changes in K-RISS time series. Results: The study incorporated 'closeness to life' and 'sustainability' indicators into K-RISS. It obtained the necessary weights through a survey of experts for integrating variables, combining indicators by data source, and aggregating sub K-RISS values. We defined caution, attention, and serious levels for both average and maximum values of daily K-RISS. Furthermore, when structural changes were detected, leading to significant variations in daily K-RISS values according to different periods, the study systematically verified these changes and derived respective severity levels for each period. Conclusions: This study enhances the existing K-RISS system and introduces more advanced indicators. K-RISS is now more comprehensively equipped to serve as a risk warning index. The study has paved the way for an objective determination of whether the food safety risk index surpasses predefined thresholds through the application of severity levels.

Axonal sprouting in the dorsal cochlear nucleus affects gap-prepulse inhibition following noise exposure

  • Kyu-Hee Han;Seog-Kyun Mun;Seonyong Sohn;Xian-Yu Piao;Ilyong Park;Munyoung Chang
    • International Journal of Molecular Medicine
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    • 제44권4호
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    • pp.1473-1483
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    • 2019
  • One of the primary theories of the pathogenesis of tinnitus involves maladaptive auditory-somatosensory plasticity in the dorsal cochlear nucleus (DCN), which is assumed to be due to axonal sprouting. Although a disrupted balance between auditory and somatosensory inputs may occur following hearing damage and may induce tinnitus, examination of this phenomenon employed a model of hearing damage that does not account for the causal relationship between these changes and tinnitus. The present study aimed to investigate changes in auditory-somatosensory innervation and the role that axonal sprouting serves in this process by comparing results between animals with and without tinnitus. Rats were exposed to a noise-inducing temporary threshold shift and were subsequently divided into tinnitus and non-tinnitus groups based on the results of gap prepulse inhibition of the acoustic startle reflex. DCNs were collected from rats divided into three sub-groups according to the number of weeks (1, 2 or 3) following noise exposure, and the protein levels of vesicular glutamate transporter 1 (VGLUT1), which is associated with auditory input to the DCN, and VGLUT2, which is in turn primarily associated with somatosensory inputs, were assessed. In addition, factors related to axonal sprouting, including growth-associated protein 43 (GAP43), postsynaptic density protein 95, synaptophysin, α-thalassemia/mental retardation syndrome X-linked homolog (ATRX), growth differentiation factor 10 (GDF10), and leucine-rich repeat and immunoglobulin domain-containing 1, were measured by western blot analyses. Compared to the non-tinnitus group, the tinnitus group exhibited a significant decrease in VGLUT1 at 1 week and a significant increase in VGLUT2 at 3 weeks post-exposure. In addition, rats in the tinnitus group exhibited significant increases in GAP43 and GDF10 protein expression levels in their DCN at 3 weeks following noise exposure. Results from the present study provided further evidence that changes in the neural input distribution to the DCN may cause tinnitus and that axonal sprouting underlies these alterations.

Catalpol and Mannitol, Two Components of Rehmannia glutinosa, Exhibit Anticonvulsant Effects Probably via GABAA Receptor Regulation

  • Kim, Mikyung;Acharya, Srijan;Botanas, Chrislean Jun;Custodio, Raly James;Lee, Hyun Jun;Sayson, Leandro Val;Abiero, Arvie;Lee, Yong Soo;Cheong, Jae Hoon;Kim, Kyeong-man;Kim, Hee Jin
    • Biomolecules & Therapeutics
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    • 제28권2호
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    • pp.137-144
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    • 2020
  • Epilepsy is a brain disorder that affects millions of people worldwide and is usually managed using currently available antiepileptic drugs, which result in adverse effects and are ineffective in approximately 20-25% of patients. Thus, there is growing interest in the development of new antiepileptic drugs with fewer side effects. In a previous study, we showed that a Rehmannia glutinosa (RG) water extract has protective effects against electroshock- and pentylenetetrazol (PTZ)-induced seizures, with fewer side effects. In this study, the objective was to identify the RG components that are responsible for its anticonvulsant effects. Initially, a number of RG components (aucubin, acteoside, catalpol, and mannitol) were screened, and the anticonvulsant effects of different doses of catalpol, mannitol, and their combination on electroshock- and chemically (PTZ or strychnine)-induced seizures in mice, were further assessed. Gamma-aminobutyric acid (GABA) receptor binding assay and electroencephalography (EEG) analysis were conducted to identify the potential underlying drug mechanism. Additionally, treated mice were tested using open-field and rotarod tests. Catalpol, mannitol, and their combination increased threshold against electroshock-induced seizures, and decreased the percentage of seizure responses induced by PTZ, a GABA antagonist. GABA receptor binding assay results revealed that catalpol and mannitol are associated with GABA receptor activity, and EEG analysis provided evidence that catalpol and mannitol have anticonvulsant effects against PTZ-induced seizures. In summary, our results indicate that catalpol and mannitol have anticonvulsant properties, and may mediate the protective effects of RG against seizures.

LI-RADS version 2018 in Patients with Prior History of Hepatocellular Carcinoma: Are LR4 Observations Enough for the Diagnosis of Recurrent HCC?

  • Kim, HeeSoo;Choi, Joon-Il;Kim, Bo Hyun;Youn, Seo Yeon;Kim, Hokun;Kim, Dong Hwan;Rha, Sung Eun
    • Investigative Magnetic Resonance Imaging
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    • 제25권3호
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    • pp.172-182
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    • 2021
  • Purpose: We evaluated the diagnostic performance of LI-RADS version 2018 using gadoxetic acid enhanced MRI for recurrent but untreated HCC in patients with prior history of HCC. Materials and Methods: We enrolled 50 consecutive patients who 1) prior history of treatment of HCC, 2) underwent liver surgery for radiological/clinical diagnosis of new HCC between 2013 to 2018, 3) had gadoxetic acid enhanced MRI within one month before surgery, and 4) did not have more than five HCCs or infiltrative tumors only. Two radiologists reviewed MRI and determined the presence of LR3, LR4 and LR5 observations except previously treated tumors based on LI-RADS version 2018 in consensus. We sub-classified LR4 into LR4m (LR4 with major features only) and LR4u (LR4 upgraded from LR3 by ancillary features). LR4u were further sub-classified into LR4ua (with arterial phase hyperenhancement) and LR4un (without arterial phase hyperenhancement). Results: PPV for LR5, LR4 and LR3 observations for recurrent HCC were 100%, 61.5% and 25.0%, respectively. 100% (3/3) of LR4m were HCC. However, PPV of LR4u was 56.5%. PPV of LR4ua and LR4un were 73.3% and 25.0%, respectively. Sensitivity of LR5 and LR5+LR4 observations as a diagnostic threshold were 32.1% and 89.3%, respectively. Sensitivity for LR5+LR4m+LR4ua observations for diagnosis of HCC were 83.7% and significantly superior to that of LR5 without significant deterioration of specificity (75.0%). Conclusion: In patients with prior history of HCC, LR4 observations by major features or with APHE may be regarded as recurrent HCCs given high sensitivity and comparable specificity/PPV to LR5 observations.

Prostaglandin D2 contributes to cisplatin-induced neuropathic pain in rats via DP2 receptor in the spinal cord

  • Li, Yaqun;Kim, Woong Mo;Kim, Seung Hoon;You, Hyun Eung;Kang, Dong Ho;Lee, Hyung Gon;Choi, Jeong Il;Yoon, Myung Ha
    • The Korean Journal of Pain
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    • 제34권1호
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    • pp.27-34
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    • 2021
  • Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a major reason for stopping or changing anticancer therapy. Among the proposed pathomechanisms underlying CIPN, proinflammatory processes have attracted increasing attention. Here we assessed the role of prostaglandin D2 (PGD2) signaling in cisplatin-induced neuropathic pain. Methods: CIPN was induced by intraperitoneal administration of cisplatin 2 mg/kg for 4 consecutive days using adult male Sprague-Dawley rats. PGD2 receptor DP1 and/or DP2 antagonists were administered intrathecally and the paw withdrawal thresholds were measured using von Frey filaments. Spinal expression of DP1, DP2, hematopoietic PGD synthase (H-PGDS), and lipocalin PGD synthase (L-PGDS) proteins were analyzed by western blotting. Results: The DP1 and DP2 antagonist AMG 853 and the selective DP2 antagonist CAY10471, but not the DP1 antagonist MK0524, significantly increased the paw withdrawal threshold compared to vehicle controls (P = 0.004 and P < 0.001, respectively). Western blotting analyses revealed comparable protein expression levels in DP1 and DP2 in the spinal cord. In the CIPN group the protein expression level of L-PGDS, but not of H-PGDS, was significantly increased compared to the control group (P < 0.001). Conclusions: The findings presented here indicate that enhanced PGD2 signaling, via upregulation of L-PGDS in the spinal cord, contributes to mechanical allodynia via DP2 receptors in a cisplatin-induced neuropathic pain model in rats, and that a blockade of DP2 receptor activation may present a novel therapeutic target for managing CIPN.

Age-dependent immune response in pigs against foot-and-mouth disease virus in vitro

  • Roh, Jae-Hee;Bui, Ngoc Anh;Lee, Hu Suk;Bui, Vuong Nghia;Dao, Duy Tung;Vu, Thanh Thi;Hoang, Thuy Thi;So, Kyoung-Min;Yi, Seung-Won;Kim, Eunju;Hur, Tai-Young;Oh, Sang-Ik
    • Journal of Animal Science and Technology
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    • 제63권6호
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    • pp.1376-1385
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    • 2021
  • Foot-and-mouth disease, one of the most contagious diseases in cloven-hoofed animals, causes significant economic losses. The pathogenesis of foot-and-mouth disease virus (FMDV) infection is known to differ with age of the animals. In this study, we aimed to reveal the difference in immunological response in the initial stage of FMDV infection between piglets and adult pigs. Peripheral blood mononuclear cells (PBMCs) were isolated from 3 piglets (8 weeks old) and 3 pigs (35 weeks old) that were not vaccinated against FMDV. O-type FMDV (2 × 102 median tissue culture infectious dose) was inoculated into porcine PBMCs and the cells were incubated at 37.0℃ under 5% CO2 for various time periods (0, 1, 3, 6, 12, 24, and 48 h). The total RNA was obtained from the FMDV-inoculated PBMCs after each time point, and the virus titer was investigated in these RNA samples. Furthermore, dynamics of mRNA expression of the six tested cytokines (interferon [IFN]-α, IFN-γ, interleukin [IL]-6, IL-8, IL-10, and tumor necrosis factor [TNF]-α) in FMDV-inoculated porcine PBMCs were evaluated by time-series analysis to determine the differences, if any, based on the age of the pigs. The PBMCs of piglets contained the highest quantity of FMDV mRNA at 6 hours post-inoculation (hpi), and the PBMCs of pigs had the highest quantity of FMDV mRNA at 3 hpi. The mean cycle threshold-value in the PBMCs steadily decreased after the peak time point in the piglets and pigs (6 and 3 hpi, respectively). The dynamics of mRNA expression of all cytokines except TNF-α showed age-dependent differences in FMDV-inoculated PBMCs. The mRNA expression of most cytokines was more pronounced in the piglets than in the pigs, implying that the immune response against FMDV showed an age-dependent difference in pigs. In conclusion, within 48 hpi, the 8-week-old piglets responded more rapidly and were more sensitive to FMDV infection than the 35-week-old pigs, which could be associated with the difference in the pathogenesis of FMDV infection among the pigs. These results provide valuable insights into the mechanisms underlying the age-dependent differences in immune response in pigs against FMDV infection.

사분위편차 및 관리도 모형에 의한 GPS 수집기반 구간통행속도 데이터 이상치 제거방안 연구 (The Quartile Deviation and the Control Chart Model of Improvement Confidence for Link Travel Speed from GPS Probe Data)

  • 한원섭;김동효;현철승;이호원;오영태;이철기
    • 한국ITS학회 논문지
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    • 제7권6호
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    • pp.21-30
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    • 2008
  • GPS를 탑재한 프로브차량에 의해 수집되는 교통정보(구간통행속도)는 차량검지기와 같이 특정링크에 대하여 연속적으로 교통정보를 수집하는 방식이 아니다. 따라서 단속교통류 구간에서 신호시간 등의 영향으로 수집되는 정보의 안정성과 대표값 등에 문제점이 있다. 본 연구는 GPS를 장착한 프로브차량에 의해 수집된 구간통행속도 데이터를 필터링하는 방법을 개발하는데 목적이 있다. 시간간격별로 수집되는 데이터에 대하여 사분위편차와 관리도에 의해 이상치를 제거하였다. 사분위편차를 적용한 결과는 제거율이 $0{\sim}3.7%$ 이고, 개별 관리도에 의한 결과는 제거율이 $0.3{\sim}7.2%$ 이었다. 두 방법 모두 교통소통이 원활한 새벽시간 대에 이상치 제거율이 낮고, 낮 시간대에 이상치 제거율이 높은 것으로 나타났다. 문제점으로 지적되는 것은 모형에 충실할 경우 Low Bound에서 이상치의 제거기준이 낮게 설정되는 것이다. 따라서 시스템 운영과정에서 경험적인 사항이 반영되어져야 할 것으로 검토된다.

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취학 전 아동의 감각처리능력에 따른 행동적 특성에 관한 연구 (The Correlation Between Sensory Processing Skills and Behavior Characteristics for Preschoolers)

  • 신지연;신혜정;조현희;차수민;김경미
    • 대한감각통합치료학회지
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    • 제3권1호
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    • pp.23-35
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    • 2005
  • Objectives : The purpose of the study is to understand the sensory processing capacity and behavioral characteristics for preschoolers without disabilities, and to investigate the relationship between sensory processing skills and the behavioral characteristics. Methods : Mothers of preschoolers without disabilities between ages of 4 and 6 who attend Y kindergarten which is located in Busan, H kindergarten in Suwon, S kindergarten in Gimhae was participated. Mothers filled out the questionnaire at home from 4th to 14th of January in 2004. We used SSP(short sensory profile) which was used by Kim, Mi-Sun in 2001 to understand the sensory processing skills. We also used Behavior During Testing Checklist find their places in Miller Assessment for preschoolers to understand behavior characteristics. The results were analyzed with SPSS 10.0. Results : 1. Total incidents in sensory processing were 157 out of 190. Among sub items of the sensory processing, the mark of lower energy/weak was highest with 4.39 point and the mark of taste/smell sensitivity was lowest with 3.60 point. Total incidents in behavioral characteristics were 20 out of 24. Among the area of behavioral characteristics, the mark of sensory responses/threshold area was highest with 2.73 point and the mark of social interaction area was lowest with 2.29 point. 2. Children's total sensory processing capacity correlates with behavioral characteristics, the more sensory processing capacity, the more behavioral characteristics. Sensory processing point correlates with behavioral characteristics points except this item, reaction to separation from caretaker. Conclusions : We hope that the children who have behavioral characteristics with difficulties in sensory processing skills can be distinguished on the basis of this studying. Also, as we find and relieve early stage of the symptoms, following study which can present based to facilitate children's social development and improve the learning ability.

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통계분포에 기반한 고해상도 SAR 영상의 변화탐지 알고리즘 구현 및 적용 (Change detection algorithm based on amplitude statistical distribution for high resolution SAR image)

  • 이기웅;강서리;김아름;송경민;이우경
    • 대한원격탐사학회지
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    • 제31권3호
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    • pp.227-244
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    • 2015
  • 최근 위성 Synthetic Aperture Radar (SAR) 영상의 해상도가 개선됨에 따라 이에 대한 수요가 증가할 것으로 보이며 향후 새로운 응용시장으로 성장할 것으로 예측되고 있다. 특히, 화산이나 지진과 같은 자연 재해에 대한 예측이나 지형의 미세한 변화를 탐지하기 위한 용도로 SAR 영상의 활용도가 증가하고 있다. 기존의 변화탐지 알고리즘을 고해상도 SAR 영상에 적용할 경우, 영상간의 기하학적 구조, 스펙클의 영향 등으로 변화탐지 정확도가 저하될 수 있다. 또한, SAR 영상의 경우 지형적 특성에 따라 영상의 통계적 분포가 다르므로 영상의 통계분포를 반영한 임계값 추정이 필요하다. 본 연구에서는 고해상도 SAR 영상의 통계적 분포특성을 반영하여 임계값을 이용하는 변화탐지 알고리즘을 제안한다. 제안된 알고리즘의 성능을 시험하기 위해 SAR 영상 시뮬레이션을 수행하여 성능을 시험하고 검증하였다. 마지막으로 Cosmo-Skymed과 다목적실용위성-5 영상에 각각 적용하여 검증하고 비교한 결과를 제시한다.

낮은 에너지의 $As_{2}^{+}$ 이온 주입을 이용한 얕은 $n^{+}-{p}$ 접합을 가진 70nm NMOSFET의 제작 (70nm NMOSFET Fabrication with Ultra-shallow $n^{+}-{p}$ Junctions Using Low Energy $As_{2}^{+}$ Implantations)

  • 최병용;성석강;이종덕;박병국
    • 대한전자공학회논문지SD
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    • 제38권2호
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    • pp.95-102
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    • 2001
  • Nano-scale의 게이트 길이를 가지는 MOSFET소자는 접합 깊이가 20∼30㎚정도로 매우 얕은 소스/드레인 확장 영역을 필요로 한다. 본 연구에서는 As₂/sup +/ 이온의 10keV이하의 낮은 에너지 이온 주입과 RTA(rapid thermal annealing)공정을 적용하여 20㎚이하의 얕은 접합 깊이와 1.O㏀/□ 이하의 낮은 면저항 값을 가지는 n/sup +/-p접합을 구현 하였다. 이렇게 형성된 n/sup +/-p 접합을 nano-scale MOSFET소자 제작에 적용 시켜서 70㎚의 게이트 길이를 가지는 NMOSFET을 제작하였다. 소스/드레인 확장 영역을 As₂/sup +/ 5keV의 이온 주입으로 형성한 100㎚의 게이트 길이를 가지는 NMOSFET의 경우, 60mV의 낮은 V/sub T/(문턱 전압감소) 와 87.2㎷의 DIBL (drain induced barrier lowering) 특성을 확인하였다. 10/sup 20/㎝/sup -3/이상의 도핑 농도를 가진 abrupt한 20㎚급의 얕은 접합, 그리고 이러한 접합이 적용된 NMOSFET소자의 전기적 특성들은 As₂/sup +/의 낮은 에너지의 이온 주입 기술이 nano-scale NMOSFET소자 제작에 적용될 수 있다는 것을 제시한다.

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