检索结果-南通市图书馆

Neural Regeneration Research 2010年第23期5卷 1773-1781页

作者： Chin Hee Mun won taek lee Kyung Ah Park Jong Eun lee Department of Anatomy Yonsei University College of Medicine Brain Korea 21 Project for Medical Science Yonsei University College of Medicine

Agmatine, an analog of L-arginine, is an endogenous substance synthesized by arginine decarboxylase, which has been shown to possess neuroprotective effects following brain ischemia. Nitric oxide is generated by sequential oxidation of the guanidinium group in L-arginine, and agmatine might protect the brain from ischemic injury by interfering with nitric oxide signaling. This study investigated the effects of agmatine on cerebral cortex neuronal injury following transient global cerebral ischemia and also detected nitric oxide synthase expression and peroxynitrite formation. Results demonstrated that intraperitoneal injection of agmatine in global cerebral ischemia/reperfusion alleviated ischemia/reperfusion-induced cerebral cortical cortex neuronal injury and cellular apoptosis, decreased neuronal and inducible nitric oxide synthase expression at 24, 48, and 72 hours following global cerebral ischemia and reperfusion, and greatly inhibited nitrotyrosine levels, which reflect the amount of peroxynitrite formed. These findings indicated that agmatine alleviates cerebral cortex neuronal injury following global cerebral ischemia and decreases nitric oxide synthase expression and peroxynitrite formation following ischemia/repeffusion.

关键词： agmatine global cerebral ischemia cerebral cortex nitric oxide nitric oxide synthase neuroprotection

Novel Perovskite Oxide Hybrid Nanofibers Embedded with Nanocatalysts for Highly Efficient and Durable Electrodes in Direct CO_(2) Electrolysis

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第5期16卷 214-230页

作者： Akromjon Akhmadjonov Kyung taek Bae Kang taek lee Department of Mechanical Engineering KAISTDaejeon 34141Republic of Korea KAIST Graduate School of Green Growth and Sustainability Daejeon 34141Republic of Korea

The unique characteristics of nanofibers in rational electrode design enable effec-tive utilization and maximizing material properties for achieving highly efficient and sustainable CO_(2) reduction reactions( CO_(2)RRs)in solid oxide elec-trolysis cells(SOECs).However,practical appli-cation of nanofiber-based electrodes faces chal-lenges in establishing sufficient interfacial contact and adhesion with the dense electrolyte.To tackle this challenge,a novel hybrid nanofiber electrode,La_(0.6)Sr_(0.4)Co_(0.15)Fe_(0.8)Pd_(0.05)O_(3-δ)(H-LSCFP),is developed by strategically incorporating low aspect ratio crushed LSCFP nanofibers into the excess porous interspace of a high aspect ratio LSCFP nanofiber framework synthesized via electrospinning technique.After consecutive treatment in 100% H_(2) and CO_(2) at 700°C,LSCFP nanofibers form a perovskite phase with in situ exsolved Co metal nanocatalysts and a high concentration of oxygen species on the surface,enhancing CO_(2) adsorption.The SOEC with the H-LSCFP electrode yielded an outstanding current density of 2.2 A cm^(-2) in CO_(2) at 800°C and 1.5 V,setting a new benchmark among reported nanofiber-based electrodes.Digital twinning of the H-LSCFP reveals improved contact adhesion and increased reaction sites for CO_(2)RR.The present work demonstrates a highly catalytically active and robust nanofiber-based fuel electrode with a hybrid structure,paving the way for further advancements and nanofiber applications in CO_(2)-SOECs.

关键词： Nanofibers Fuel electrodes Digital twinning CO_(2)reduction reaction Solid oxide electrolysis cells

Value of glucose transport protein 1 expression in detecting lymph node metastasis in patients with colorectal cancer

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第5期12卷 931-941页

作者： Hongsik Kim Song-Yi Choi Tae-Young Heo Kyeong-Rok Kim Jisun lee Min Young Yoo taek-Gu lee Joung-Ho Han Department of Internal Medicine Chungbuk National University HospitalCheongju 28644South Korea Department of Pathology Chungnam National University College of MedicineDaejeon 35015South Korea Information and Statistics Chungbuk National UniversityCheongju 28644South Korea Department of Radiology College of MedicineChungbuk National UniversityChungbuk National University HospitalCheongju-si 28644South Korea Department of Nuclear Medicine School of MedicineInha UniversityIncheon 22332South Korea Department of Surgery Chungbuk National UniversityCollege of MedicineCheongju-si 28644South Korea Department of Internal Medicen Chungbuk National UniversityCollege of medicineCheongju-si 28644South Korea

BACKGROUND There are limited data on the use of glucose transport protein 1(GLUT-1)expre-ssion as a biomarker for predicting lymph node metastasis in patients with colorectal cancer.GLUT-1 and GLUT-3,hexokinase(HK)-II,and hypoxia-induced factor(HIF)-1 expressions may be useful biomarkers for detecting primary tumors and lymph node metastasis when combined with fluorodeoxyglucose(FDG)uptake on positron emission tomography/computed tomography(PET/CT).AIM To evaluate GLUT-1,GLUT-3,HK-II,and HIF-1 expressions as biomarkers for detecting primary tumors and lymph node metastasis with 18F-FDG-PET/CT.METHODS This retrospective study included 169 patients with colorectal cancer who underwent colectomy and preoperative 18F-FDG-PET/CT at Chungbuk National University Hospital between January 2009 and May 2012.Two tissue cores from the central and peripheral areas of the tumors were obtained and were examined by a dedicated pathologist,and the expressions of GLUT-1,GLUT-3,HK-II,and HIF-1 were determined using immunohisto-chemical staining.We analyzed the correlations among their expressions,various clinicopathological factors,and the maximum standardized uptake value(SUVmax)of PET/CT.RESULTS GLUT-1 was found at the center or periphery of the tumors in 109(64.5%)of the 169 patients.GLUT-1 positivity was significantly correlated with the SUVmax of the primary tumor and lymph nodes,regardless of the biopsy site(tumor center,P<0.001 and P=0.012;tumor periphery,P=0.030 and P=0.010,respectively).GLUT-1 positivity and negativity were associated with higher and lower sensitivities of PET/CT,respectively,for the detection of lymph node metastasis,regardless of the biopsy site.GLUT3,HK-II,and HIF-1 expressions were not significantly correlated with the SUVmax of the primary tumor and lymph nodes.CONCLUSION GLUT-1 expression was significantly correlated with the SUVmax of 18F-FDG-PET/CT for primary tumors and lymph nodes.Clinicians should consider GLUT-1 expression in preoperative endoscopic biopsy in interpreting PET/CT findings.

关键词： 18F-FDG-PET-CT Biomarker Colorectal neoplasms Glucose transporter type 1 Lymph node

Complicated calcified alloplastic implants in the nasal dorsum:A clinical analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第18期12卷 3351-3359页

作者： Yong-Seon Hwang taek-Kyun Kim Dong-Jun Yang Si-Hyong Jang Da-Woon lee Department of Plastic and Reconstructive Surgery College of MedicineSoonchunhyang UniversityCheonan-Si 31151South Korea Department of Plastic Surgery The PLUS Plastic Surgery ClinicSeoul 06035South Korea Department of Plastic Surgery CDU Plastic Surgery ClinicSeoul 06067South Korea Department of Pathology College of MedicineSoonchunhyang UniversityCheonan 31151Chungcheongnam-doSouth Korea

BACKGROUND In rhinoplasty,calcification around silicone implants is frequently observed in the tip dorsum(TD)area.Additionally,based on a review of various literature,it is presumed that calcification in silicone implants occurs due to both inflammatory chemical reactions and physical friction against the tissue.The calcification of nasal silicone implants not only results in the functional loss of the implants,but also leads to material deformation.However,there is a lack of research on calcification of nasal silicone implants in the current literature.AIM To elucidate various clinical characteristics of calcification around nasal silicone implants,using histological and radiological analysis.METHODS This study analyzed data from 16 patients of calcified nasal implants,who underwent revision rhinoplasty for various reasons after undergoing augmentation rhinoplasty with silicone implants.The collected data included information on implant duration,implant types,location of calcification,presence of inflammatory reactions,and computed tomography(CT)scans.RESULTS The most common location of calcification,as visually analyzed,was in the TD area,accounting for 56%.Additionally,the analysis of CT scans revealed a trend of increasing Hounsfield Unit values for calcification with the duration of implantation,although this trend was not statistically significant(P=0.139).CONCLUSION Our study shows that reducing the frequency of calcification may be achievable by using softer silicone implants and by minimizing the damage to perioperative tissues.

关键词： Silicone implants Rhinoplasty Calcification Complication Hounsfield unit

Application of automated cone penetrometer for railway investigation using correlations with DCPI and deflection modulus

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Cold and Arid Regions 2022年第4期14卷 235-238页

作者： Sang Yeob Kim won-taek Hong Jong-Sub lee School of Civil Environmental and Architectural EngineeringKorea UniversitySeoul 02841Republic of Korea Department of Civil&Environmental Engineering Gachon UniversitySeongnam-si 13120Republic of Korea

Portable in-situ devices have been used for characterizing low accessible field,such as the railway subgrade.In this study,the automated cone penetrometer(ACP)was designed for the application on the railway subgrade.ACP is composed of the cone tip,driving rod,and hydraulic hammer system.The hydraulic motor lifts and drops the 294.3 N hammer from a height of 200 mm such that the potential energy of 58.9 N m impacts the driving rod.The N-value(NACP)from the ACP test was compared with the dynamic cone penetration index(DCPI)from the dynamic cone penetrometer(DCP)test.The test results show that the NACP and DCPI profiles show opposite trend owing to the inverse concept of the unit.From the correlation of DCPI and NACP,the limitation of DCPI reveals owing the minimum manually measured value of 1 mm/blow.Additionally,the evaluation of the deflection modulus(EFWD)using NACP is more efficient than that using DCPI.Based on the result of this study,we suggest that ACP can be used for strength and stiffness evaluation of railway subgrade rapidly and reliably.

关键词： Automated cone penetrometer DCPI E_(FWD )N_(ACP) Railway subgrade

Winter distribution of diatom assemblages along the coastline of R.O.Korea in 2010

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2022年第6期41卷 68-77页

作者： Joon Sang Park Kyun-Woo lee Seung won Jung taek-Kyun lee Hyoung Min Joo Library of Marine Samples Korea Institute of Ocean Science&TechnologyGeoje 53201R.O.Korea Marine Biotechnology Research Center Korea Institute of Ocean Science&TechnologyBusan 49111R.O.Korea Risk Assessment Research Center Korea Institute of Ocean Science&TechnologyGeoje 53201R.O.Korea Unit of Next Generation IBRV Building Program Korea Polar Research InstituteIncheon 21990R.O.Korea

Diatoms are a globally successful and eukaryotic photosynthetic organism with an ornamented silica external wall.The relationship between their valve morphology and habitat means that diatoms can be used as bioindicators to characterize the aquatic environment.To estimate the differential distribution and diversity of diatom assemblages along the coastal line,we collected phytoplankton samples from 114 coastal sites of waters of R.O.Korea.We applied the unweighted pair-group technique using the arithmetic averages clustering method to cluster the sampling sites,apart from those where the biota consisted of other groups,such as dinoflagellates,into four regions:the Yellow Sea,South Sea,southern East Sea,and northern East Sea.Indicator species analysis in each region led to the selection of tychoplanktonic,chain-forming,attached species to substrates and psychrophilic indicator diatoms,respectively,each of which represented a planktonic lifestyle associated with one of the four regions.This study shows the diatom assemblages to serve as bioindicators of Korean coastal water in winter,and the subsequent seasonal survey will provide a starting point for the improved understanding of Korean diatom-based ecoregions,in both time and space.

关键词： diatom assemblage indicator species life-form Korean coastal waters species diversity

Programmable Logic Controller Block Monitoring System for Memory Attack Defense in Industrial Control Systems

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2023年第11期77卷 2427-2442页

作者： Mingyu lee Jiho Shin Jung taek Seo Department of Information Security Gachon UniversitySeongnam13120Korea Police Science Institute Korean National Police UniversityAsan31539Korea Department of Computer Engineering Gachon UniversitySeongnam13120Korea

Cyberattacks targeting industrial control systems(ICS)are becoming more sophisticated and advanced than in the past.A programmable logic controller(PLC),a core component of ICS,controls and monitors sensors and actuators in the field.However,PLC has memory attack threats such as program injection and manipulation,which has long been a major target for attackers,and it is important to detect these attacks for ICS security.To detect PLC memory attacks,a security system is required to acquire and monitor PLC memory directly.In addition,the performance impact of the security system on the PLC makes it difficult to apply to the ICS.To address these challenges,this paper proposes a system to detect PLC memory attacks by continuously acquiring and monitoring PLC memory.The proposed system detects PLC memory attacks by acquiring the program blocks and block information directly from the same layer as the PLC and then comparing them in bytes with previous data.Experiments with Siemens S7-300 and S7-400 PLC were conducted to evaluate the PLC memory detection performance and performance impact on PLC.The experimental results demonstrate that the proposed system detects all malicious organization block(OB)injection and data block(DB)manipulation,and the increment of PLC cycle time,the impact on PLC performance,was less than 1 ms.The proposed system detects PLC memory attacks with a simpler detection method than earlier studies.Furthermore,the proposed system can be applied to ICS with a small performance impact on PLC.

关键词： Programmable logic controller industrial control system attack detection

Solar Power Plant Network Packet-Based Anomaly Detection System for Cybersecurity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2023年第10期77卷 757-779页

作者： Ju Hyeon lee Jiho Shin Jung taek Seo Department of Information Security Gachon UniversitySeongnam13120Korea Police Science Institute Korean National Police UniversityAsan31539Korea Department of Computer Engineering Gachon UniversitySeongnam13120Korea

As energy-related problems continue to emerge,the need for stable energy supplies and issues regarding both environmental and safety require urgent consideration.Renewable energy is becoming increasingly important,with solar power accounting for the most significant proportion of renewables.As the scale and importance of solar energy have increased,cyber threats against solar power plants have also increased.So,we need an anomaly detection system that effectively detects cyber threats to solar power plants.However,as mentioned earlier,the existing solar power plant anomaly detection system monitors only operating information such as power generation,making it difficult to detect cyberattacks.To address this issue,in this paper,we propose a network packet-based anomaly detection system for the Programmable Logic Controller(PLC)of the inverter,an essential system of photovoltaic plants,to detect cyber threats.Cyberattacks and vulnerabilities in solar power plants were analyzed to identify cyber threats in solar power plants.The analysis shows that Denial of Service(DoS)and Manin-the-Middle(MitM)attacks are primarily carried out on inverters,aiming to disrupt solar plant operations.To develop an anomaly detection system,we performed preprocessing,such as correlation analysis and normalization for PLC network packets data and trained various machine learning-based classification models on such data.The Random Forest model showed the best performance with an accuracy of 97.36%.The proposed system can detect anomalies based on network packets,identify potential cyber threats that cannot be identified by the anomaly detection system currently in use in solar power plants,and enhance the security of solar plants.

关键词： Renewable energy solar power plant cyber threat cybersecurity anomaly detection machine learning network packet

Network Traffic Obfuscation System for IIoT-Cloud Control Systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第9期72卷 4911-4929页

作者： Yangjae lee Sung Hoon Baek Jung taek Seo Ki-Woong Park SysCore Lab. Sejong UniversitySeoul05006Korea Department of Computer System Engineering Jungwon UniversityChungcheongbuk-do28024Korea Department of Computer Engineering Gachon UniversityGyeonggi-do13120Korea

One of the latest technologies enabling remote control,operational efficiency upgrades,and real-time big-data monitoring in an industrial control system(ICS)is the IIoT-Cloud ICS,which integrates the Industrial Internet of Things(IIoT)and the cloud into the ICS.Although an ICS benefits from the application of IIoT and the cloud in terms of cost reduction,efficiency improvement,and real-time monitoring,the application of this technology to an ICS poses an unprecedented security risk by exposing its terminal devices to the outside world.An adversary can collect information regarding senders,recipients,and prime-time slots through traffic analysis and use it as a linchpin for the next attack,posing a potential threat to the ICS.To address this problem,we designed a network traffic obfuscation system(NTOS)for the IIoT-Cloud ICS,based on the requirements derived from the ICS characteristics and limitations of existing NTOS models.As a strategy to solve this problem wherein a decrease in the traffic volume facilitates traffic analysis or reduces the packet transmission speed,we proposed an NTOS based on packet scrambling,wherein a packet is split into multiple pieces before transmission,thus obfuscating network analysis.To minimize the ICS modification and downtime,the proposed NTOS was designed using an agentbased model.In addition,for the ICS network traffic analyzer to operate normally in an environment wherein the NTOS is applied,a rule-based NTOS was adopted such that the actual traffic flow is known only to the device that is aware of the rule and is blocked for attackers.The experimental results verified that the same time requested for response and level of difficulty of analysis were maintained by the application of an NTOS based on packet scrambling,even when the number of requests received by the server per second was reduced.The network traffic analyzer of the ICS can capture the packet flow by using the pre-communicated NTOS rule.In addition,by designing an NTOS using an agent-based model,the impact on the

关键词： Cloud computing system moving-target defense container orchestration

Upconverting nanoparticle-containing erythrocyte-sized hemoglobin microgels that generate heat,oxygen and reactive oxygen species for suppressing hypoxic tumors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Bioactive Materials 2023年第4期22卷 112-126页

作者： Hanju Kim Johyun Yoon Hwang Kyung Kim Woo Tak lee Nguyen Thi Nguyen Xuan Thien Le Eun-Hee lee Eun Seong lee Kyung taek Oh Han-Gon Choi Yu Seok Youn School of Pharmacy Sungkyunkwan University2066 Seobu-roJangan-guSuwonGyeonggi-do16419Republic of Korea College of Pharmacy Korea University2511 Sejong-roSejong30019Republic of Korea Department of Biotechnology and Department of Biomedical-Chemical Engineering the Catholic University of Korea43 Jibong-roBucheon-siGyeonggi-do14662Republic of Korea College of Pharmacy Chung-Ang University84 Heukseok-roDongjak-guSeoul06974Republic of Korea College of Pharmacy Hanyang University55Hanyangdaehak-roSangnok-guAnsan15588Republic of Korea

Inspired by erythrocytes that contain oxygen-carrying hemoglobin(Hb)and that exhibit photo-driven activity,we introduce homogenous-sized erythrocyte-like Hb microgel(μGel)systems(5-6μm)that can(i)emit heat,(ii)supply oxygen,and(iii)generate reactive oxygen species(ROS;1O2)in response to near-infrared(NIR)laser irradiation.Hb μGels consist of Hb,bovine serum albumin(BSA),chlorin e6(Ce6)and erbium@lutetium upconverting nanoparticles(UCNPs;~35 nm)that effectively convert 808 nm NIR light to 660 nm visible light.These Hb μGels are capable of releasing oxygen to help generate sufficient reactive oxygen species(^(1)O_(2))from UCNPs/Ce6 under severely hypoxic condition upon NIR stimulation for efficient photodynamic activity.Moreover,the Hb μGels emit heat and increase surface temperature due to NIR light absorption by heme(iron protoporphyrin IX)and display photothermal activity.By changing the Hb/UCNP/Ce6 ratio and controlling the amount of NIR laser irradiation,it is possible to formulate bespoke Hb μGels with either photothermal or photodynamic activity or both in the context of combined therapeutic effect.These Hb μGels effectively suppress highly hypoxic 4T1 cell spheroid growth and xenograft mice tumors in vivo.

关键词： Hemoglobin microgel Upconversion Photothermal therapy Photodynamic therapy Hypoxic tumors Oxygen-generation