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韩国高速列车防撞设计与评估

中国铁道科学 2004年第1期25卷 1-7页

作者： Jeong-Seo koo tae-Soo Kwon Hyun-Jik Cho KoreanRailroadResearshInstitute KoreanRailroadResearshInstituteKoreanRailroadResearshInstitute UiwangcityKyonggiDo437050KoreaUiwangcityKyonggiDo437050KoreaUiwangcityKyonggiDo437050Korea

针对韩国高速列车(KHSt)的防撞性能进行深入地研究。选定行驶速度为110km·h-1的列车与一个15t重的刚性障碍物的撞击、两列行驶速度为30km·h-1的列车相撞作为严重撞击的事故场景,两列行驶速度为8km·h-1的列车相撞作为轻度撞击的事故... 详细信息

针对韩国高速列车(KHSt)的防撞性能进行深入地研究。选定行驶速度为110km·h-1的列车与一个15t重的刚性障碍物的撞击、两列行驶速度为30km·h-1的列车相撞作为严重撞击的事故场景,两列行驶速度为8km·h-1的列车相撞作为轻度撞击的事故场景。用有限元方法对KHSt的防撞性进行了数学评估。一维和二维的仿真分析表明该车整体上具有良好的耐撞性。同时,对动车的前端部分做了三维壳体单元的仿真分析。使用安全带的旅客伤亡试验的结果说明KHSt的良好性能足以在设置的事故场景中保护旅客的安全。最后,用实比例的撞击试验对仿真方法进行了验证。

关键词：高速列车防撞性能有限元法铁路安全试验评估

Ethanol extract from Gynostemma pentaphyllum ameliorates dopaminergic neuronal cell death in transgenic mice expressing mutant A53t human alpha-synuclein

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Neural Regeneration Research 2020年第2期15卷 361-368页

作者： Hyun Jin Park ting ting Zhao Seung Hwan Kim Chong Kil Lee Bang Yeon Hwang Kyung Eun Lee Myung koo Lee Department of Pharmacy College of PharmacyChungbuk National UniversityCheongjuRepublic of Korea 2Research Center for Bioresource and Health College of PharmacyChungbuk National UniversityCheongjuRepublic of Korea Department of Social Physical Education Songwon UniversityGwangjuRepublic of Korea

Gynostemma(G.) pentaphyllum(Cucurbitaceae) contains various bioactive gypenosides. Ethanol extract from G. pentaphyllum(GP-EX) has been shown to have ameliorative effects on the death of dopaminergic neurons in animal models of Parkinson’s disease(PD) induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-and 6-hydroxydopamine. PD patients exhibit multiple symptoms, so PD-related research should combine neurotoxin models with genetic models. In the present study, we investigated the ameliorative effects of GP-EX, including gypenosides, on the cell death of dopaminergic neurons in the midbrain of A53 t α-synuclein transgenic mouse models of PD(A53 t). Both GP-EX and gypenosides at 50 mg/kg per day were orally administered to the A53 t mice for 20 weeks.α-Synuclein-immunopositive cells and α-synuclein phosphorylation were increased in the midbrain of A53 t mice, which was reduced following treatment with GP-EX. treatment with GP-EX modulated the reduced phosphorylation of tyrosine hydroxylase, extracellular signal-regulated kinase(ERK1/2), Bcl-2-associated death promoter(Bad) at Ser112, and c-Jun N-terminal kinase(JNK1/2) due to α-synuclein overexpression. In the A53 t group, GP-EX treatment prolonged the latency of the step-through passive avoidance test and shortened the transfer latency of the elevated plus maze test. Gypenosides treatment exhibited the effects and efficacy similar to those of GP-EX. taken together, GP-EX, including gypenosides, has ameliorative effects on dopaminergic neuronal cell death due to the overexpression of α-synuclein by modulating ERK1/2, Bad at Ser112, and JNK1/2 signaling in the midbrain of A53 t mouse model of PD. Further studies are needed to investigate GP-EX as a treatment for neurodegenerative synucleinopathies, including PD. this study was approved by the Animal Ethics Committee of Chungbuk National University(approval No. CBNUA-956-16-01) on September 21, 2016.

关键词： A53t α-synuclein genetic mice ERK1/2 gynostemma pentaphyllum gypenosides Parkinson’s disease retention transfer latency time

Hypothyroidism affects astrocyte and microglial morphology in type 2 diabetes

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Neural Regeneration Research 2013年第26期8卷 2458-2467页

作者： Sung Min Nam Yo Na Kim Dae Young Yoo Sun Shin Yi Jung Hoon Choi In koo Hwang Je Kyung Seong Yeo Sung Yoon Department of Anatomy and Cell Biology College of Veterinary Medicine Research Institute for Veterinary Science Seoul National University Department of Biomedical Laboratory Science College of Biomedical Sciences Soonchunhyang University Department of Anatomy College of Veterinary Medicine Kangwon National University

In the present study, we investigated the effects of hypothyroidism on the morphology of astrocytes and microglia in the hippocampus of Zucker diabetic fatty rats and Zucker lean control rats. to induce hypothyroidism, Zucker lean control and Zucker diabetic fatty rats at 7 weeks of age orally received the vehicle or methimazole, an anti-thyroid drug, treatment for 5 weeks and were sacrificed at 12 weeks of age in all groups for blood chemistry and immunohistochemical staining. In the me- thimazole-treated Zucker lean control and Zucker diabetic fatty rats, the serum circulating triiodo- thyronine （t3） and thyroxine （＇I＂4） levels were significantly decreased compared to levels observed in the vehicle-treated Zucker lean control or Zucker diabetic fatty rats. this reduction was more prominent in the methimazole-treated Zucker diabetic fatty group. Glial fibrillary acidic protein im- munoreactive astrocytes and ionized calcium-binding adapter molecule 1 （Iba-1）-immunoreactive microglia in the Zucker lean control and Zucker diabetic fatty group were diffusely detected in the hippocampal CA1 region and dentate gyrus. there were no significant differences in the glial fibril- lary acidic protein and Iba-1 immunoreactivity in the CA1 region and dentate gyrus between Zucker lean control and Zucker diabetic fatty groups. However, in the methimazole-treated Zucker lean control and Zucker diabetic fatty groups, the processes of glial fibrillary acidic protein immunoreac- tive astrocytes and Iba-1 immunoreactive microglia, were significantly decreased in both the CA1 region and dentate gyrus compared to that in the vehicle-treated Zucker lean control and Zucker diabetic fatty groups. these results suggest that diabetes has no effect on the morphology of as- trocytes and microglia and that hypothyroidism during the onset of diabetes prominently reduces the processes of astrocytes and microglia.

关键词： neural regeneration astrocytes microglia diabetes hypothyroidism complications thyroid hormone obesity methimazole Zucker diabetic fatty rat grants-supported paper neuroregeneration

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韩中FtA对韩国农产品贸易的影响研究

韩中FTA对韩国农产品贸易的影响研究

作者： koo HEESEUNG 山东大学

学位级别：硕士

世界经济一体化促进了世界各国的贸易活动和区域经济一体化进程。随着贸易自由化的不断推进和跨国投资的增加,世界和区域的一体化也不断地发展起来。而且世界上大部分国家的对外贸易和投资也发生在区域范围内,比如NA FtA中的美、加、墨... 详细信息

世界经济一体化促进了世界各国的贸易活动和区域经济一体化进程。随着贸易自由化的不断推进和跨国投资的增加,世界和区域的一体化也不断地发展起来。而且世界上大部分国家的对外贸易和投资也发生在区域范围内,比如NA FtA中的美、加、墨三国,欧盟成员国,ASEAN成员国等。韩国和中国的经济发展中,两国的贸易对双方经济增长贡献比较大,韩国对外贸易对其经济的贡献率是出口贡献25%进口贡献21%,中国的出口贡献率为4%进口贡献率为10%。2015年12月20日,韩国和中国缔结的FtA终于生效。在这种背景下,本论文研究FtA缔结对韩国农产品贸易的影响。由于韩国和中国两国的贸易中,韩中农产品贸易对韩国经济影响较大,所以韩中FtA缔结过程中农产品部门的贸易协商是韩国最关心的事情。FtA协商最大的目标是追求协商国家之间的利益最大化。韩国和中国两国1992年建交以后两国的经济关系逐渐发展和加强。而且中国是韩国的最大贸易伙伴国,韩国对中国贸易依赖度也逐渐上升。从2000年的59.2%上升到2014年的75.8%。随着中国经济急速的发展,韩国和中国两国之间的贸易量和贸易金额也越来越大。2016年韩中贸易额达出口 1,244亿美元、进口86亿美元,中国是韩国的最大贸易伙伴。本论文拟对韩中两国的的农产品贸易展开研究。具体来说,本文探讨韩中两国1992年建交以来的经济通商协力越来越亲密的情况下,韩中两国的农产品贸易现状;比较韩国和中国的农业特点与农业政策;比较韩中两国的农产品贸易规模、贸易种类与结构;对比两国农产品的贸易地理方向,和论及两国农产品贸易的摩擦。然后分析韩国和中国在FtA框架下,韩国农产品贸易的SWO t。即论证韩国农产品的竞争优势、韩国农产品的竞争劣势、韩国农产品贸易的机遇和威胁。并进一步论证韩中两国FtA框架下的农产品贸易效应与影响。最后,总结本研究并给出两国进一步发展农产品贸易的策略与建议。

关键词：韩中FtA 农产品贸易效应

Effect of sintering temperature on structure, magnetic and magnetocaloric properties of La_(0.6)Ca_(0.4)MnO_3 manganite

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transactions of Nonferrous Metals Society of China 2014年第S1期24卷 141-145页

作者： Seung Rok LEE M.S.ANWAR Faheem AHMED Bon Heun koo School of Materials Science and Engineering Changwon National University

the effect of sintering temperature on the structure, magnetic transition and magnetic entropy of La0.6Ca0.4MnO3 manganite was studied. It was observed that this compound belongs to the orthorhombic structure with the Pnma space group without any impurity phase. the effect of sintering temperature on the Curie temperature(tC) was studied. the small increment in tC is found with increasing the sintering temperature. the magnetocaloric study exposes a quite large change of the magnetic entropy, which varies with sintering temperature. For an applied magnetic field of 3 t and sintering temperature of 1300 °C, the relative cooling power(RCP) is 89 J/kg. As a result, the studied compound can be considered as potential material for magnetic refrigeration near and below room temperature.

关键词： manganite magnetocaloric effect sintering temperature colossal magnetoresistance

Methods for improving colorectal cancer annotation efficiency for artificial intelligence-observer training

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World Journal of Radiology 2023年第12期15卷 359-369页

作者： Matthew Grudza Brandon Salinel Sarah Zeien Matthew Murphy Jake Adkins Corey t Jensen Curtis Bay Vikram Kodibagkar Phillip koo tomislav Dragovich Michael A Choti Madappa Kundranda tanveer Syeda-Mahmood Hong-Zhi Wang john Chang School of Biological Health and Systems Engineering Arizona State UniversityTempeAZ 85287United States Department of Radiology Banner MD Anderson Cancer CenterGilbertAZ 85234United States School of Osteopathic Medicine A.T.Still UniversityMesaAZ 85206United States Department of Abdominal Imaging MD Anderson Cancer CenterHoustonTX 77030United States Department of Abdominal Imaging University Texas MD Anderson Cancer CenterHoustonTX 77030United States Department of Interdisciplinary Sciences A.T.Still UniversityMesaAZ 85206United States School of Biological and Health Systems Engineering Arizona State UniversityTempeAZ 85287United States Division of Cancer Medicine Banner MD Anderson Cancer CenterGilbertAZ 85234United States Department of Surgical Oncology Banner MD Anderson Cancer CenterGilbertAZ 85234United States IBM Almaden Research Center IBMSan JoseCA 95120United States

BACKGROUND Missing occult cancer lesions accounts for the most diagnostic errors in retrospective radiology reviews as early cancer can be small or subtle,making the lesions difficult to *** is the most effective technique for reducing these events and can be economically implemented with the advent of artificial intelligence(AI).AIM to achieve appropriate AI model training,a large annotated dataset is necessary to train the AI *** goal in this research is to compare two methods for decreasing the annotation time to establish ground truth:Skip-slice annotation and AI-initiated *** We developed a 2D U-Net as an AI second observer for detecting colorectal cancer(CRC)and an ensemble of 5 differently initiated 2D U-Net for ensemble *** model was trained with 51 cases of annotated CRC computed tomography of the abdomen and pelvis,tested with 7 cases,and validated with 20 cases from the Cancer Imaging Archive *** sensitivity,false positives per case,and estimated Dice coefficient were obtained for each method of *** compared the two methods of annotations and the time reduction associated with the *** time differences were tested using Friedman’s two-way analysis of *** Sparse annotation significantly reduces the time for annotation particularly skipping 2 slices at a time(Ption of up to 2/3 of the annotation does not reduce AI model sensitivity or false positives per *** initializing human annotation with AI reduces the annotation time,the reduction is minimal,even when using an ensemble AI to decrease false *** Our data support the sparse annotation technique as an efficient technique for reducing the time needed to establish the ground truth.

关键词： Artificial intelligence Colorectal cancer Detection

Acute hospital-community hospital care bundle for elderly orthopedic surgery patients:A propensity score-matched economic analysis

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World Journal of Orthopedics 2023年第4期14卷 231-239页

作者： Ivan En-Howe tan Aik Yong Chok Yun Zhao Yonghui Chen Chee Hoe koo Junjie Aw Mave Hean teng Soh Chek Hun Foo Kwok Ann Ang Emile john Kwong Wei tan Andrew Hwee Chye tan Marianne Kit Har Au Group Finance Singapore Health ServicesSingapore 168582Singapore Department of Colorectal Surgery Singapore General HospitalSingapore 169608Singapore Post-Acute and Continuing Care Family MedicineOutram Community HospitalSingapore 168582Singapore Finance Singapore General HospitalSingapore 169608Singapore Department of Orthopedic Surgery Singapore General HospitalSingapore 169856Singapore Singhealth Community Hospital Singapore 168582Singapore

BACKGROUND While Singapore attains good health outcomes,Singapore’s healthcare system is confronted with bed shortages and prolonged stays for elderly people recovering from surgery in acute *** Acute Hospital-Community Hospital(AHCH)care bundle has been developed to assist patients in postoperative *** core concept is to transfer patients out of AHs when clinically recommended and into CHs,where they can receive more beneficial dedicated care to aid in their recovery,while freeing up bed capacities in *** to analyze the AH length of stay(LOS),costs,and savings associated with the AH-CH care bundle intervention initiated and implemented in elderly patients aged 75 years and above undergoing elective orthopedic *** A total of 8621:1 propensity score-matched patients aged 75 years and above who underwent elective orthopedic surgery in Singapore General Hospital(SGH)before(2017-2018)and after(2019-2021)the care bundle intervention period was *** measures were AH LOS,CH LOS,hospitalization metrics,postoperative 30-d mortality,and modified Barthel Index(MBI)*** costs of AH inpatient hospital stay in the matched cohorts were compared using cost data in Singapore *** Of the 862 matched elderly patients undergoing elective orthopedic surgery before and after the care bundle intervention,the age distribution,sex,American Society of Anesthesiologists classification,Charlson Comorbidity Index,and surgical approach were comparable between both *** transferred to CHs after the surgery had a shorter median AH LOS(7 d vs 9 d,Pthe mean total AH inpatient cost per patient was 14.9%less for the elderly group transferred to CHs(S$24497.3 vs S$28772.8,Pthe overall AH U-turn rates for elderly patients within the care bundle were low,with a 0%mortality rate following orthopedic *** elderly patients were discharged from CHs,their MBI scores increased significantly(50.9 vs 71.9,P<0.

关键词： Care bundle Community hospital Orthopedic surgery Cost-effectiveness Care transition Intervention

Ssu72 is a t-cell receptor-responsive modifier that is indispensable for regulatory t cells

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Cellular & Molecular Immunology 2021年第6期18卷 1395-1411页

作者： Jin-Kwan Lee Seo-Young koo Hye-Mi Nam Jee-Boong Lee Jiwon Ko Kyung-Mo Kim Eun-Ji Park tae Jin Kim Ho Lee Heounjeong Go Chang-Woo Lee Research Institute Curogen TechnologySuwonSouth Korea Department of Molecular Cell Biology Samsung Medical CenterSungkyunkwan University School of MedicineSuwonSouth Korea MOGAM Institute for Biomedical Research GyeonggiSouth Korea Department of Pathology Asan Medical CenterUniversity of Ulsan College of MedicineSeoulSouth Korea Asan Institute for Life Sciences Asan Medical CenterUniversity of Ulsan College of MedicineSeoulSouth Korea Department of Immunology Sungkyunkwan University School of MedicineSeoulSouth Korea Department of Cancer Biomedical Science Graduate School of Cancer Science and PolicyResearch InstituteNational Cancer CenterGyeonggiSouth Korea

the homeostatic balance between effector t cells and regulatory t cells(tregs)is crucial for adaptive immunity;however,epigenetic programs that inhibit phosphorylation to regulate treg development,peripheral expression,and suppressive activity are ***,we found that the Ssu72 phosphatase is activated by various t-cell receptor signaling pathways,including the t-cell receptor and IL-2R pathways,and localizes at the cell *** of Ssu72 in t cells disrupts CD4+t-cell differentiation into tregs in the periphery via the production of high levels of the effector cytokines IL-2 and IFNγ,which induce CD4+t-cell activation and differentiation into effector cell *** also found a close correlation between downregulation of Ssu72 and severe defects in mucosal tolerance in ***,Ssu72 forms a complex with PLCγ1,which is an essential effector molecule for t-cell receptor signaling as well as treg development and ***72 deficiency impairs PLCγ1 downstream signaling and results in failure of Foxp3 ***,our studies show that the Ssu72-mediated cytokine response coordinates the differentiation and function of treg cells in the periphery.

关键词： Ssu72 Regulatory t cells FoxP3 t cell receptor Autoimmunity

Sleep deprivation increase the expression of inducible heat shock protein 70 in rat gastric mucosa

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World Journal of Gastroenterology 2001年第4期7卷 496-499页

作者： Xi-Zhong Shen Marcel W.L. koo Chi-Hin Cho Department of Gastroenterology,Zhongshan Hospital,Fudan University,136 Yixueyuan Road,Shanghai 200032,ChinaDepartment of Pharmacology.Faculty of Medicine,University of Hong Kong,5 Sassoon Road,Pokfulam,Hong Kong,ChinaSupported by .Dr.Marcel W.L.koo,Department of Pharmacology,FacuLty of Medicine,the University of Hong Kong,5 Sassoon Road,Hong Kong,China.Wlkoo@hkusua.hku.hk Department of Pharmacology Faculty of Medicine The University of Hong Kong 5 Sassoon Road Hong Kong China.

AIM: to investigate if sleep deprivation is able to increase the expression of inducible heat shock protein 70 in gastric mucosa and its possible role in mucosal defense. MEtHODS: Rats for sleep disruption were placed inside a computerized rotating drum, gastric mucosa was taken from rats with 1, 3 and 7d sleep deprivation. Rt-PCR, immunohistochemistry and Western blotting were used to determine the expression of heat shock protein 70. Ethanol (500mL.L(-1), i.g.) was used to induce gastric mucosa damage. RESULtS: Rt-PCR, Western blotting and immunostaining confirmed that the sleep deprivation as a stress resulted in significantly greater expression of inducible heat shock protein 70 in gastric mucosa of rats. After the 500mL.L(-1) ethanol challenge, the ulcer area found in the rats with 7d sleep deprivation (19.15 +/- 4.2)mm(2) was significantly lower (P<0.01) than the corresponding control (53.7 +/- 8.1) mm(2). CONCLUSION: Sleep deprivation as a stress, in addition to lowering the gastric mucosal barrier, is able to stimulate the expression of inducible heat shock protein 70 in gastric mucosa of rats, the heat shock protein 70 may play an important role in gastric mucosal protection.

关键词： Animals Central Nervous System Depressants Ethanol Gastric Mucosa Gene Expression HSP70 Heat-Shock Proteins Immunohistochemistry Male RNA, Messenger Rats Rats, Sprague-Dawley Research Support, Non-U.S. Gov't Sleep Deprivation Stomach Ulcer control