检索结果-南通市图书馆

Open Journal of Fluid Dynamics 2014年第3期4卷 251-262页

作者： Jung-Yup Kim hyun-Joon Shin Chan-Sol ahn Ji-Seok Kim sang-hyun Joo Fire Research Center Korea Institute of Civil Engineering and Building Technology Goyang Korea

The pressurization smoke control system has been commonly used as a smoke control system at the emergency stairs of high-rise buildings. However, a higher possibility of overpressure between the lobby and the accommodation or pressure drop in the lobby could lead to failure in achievement of the purpose of pressurization system, particularly when supplying the leakage and supplementary air flow through one air-supply path at a time. To improve this particular issue, the devise configurations, as well as the different ways to supply the leakage and supplementary air flow through the different flow passages have been proposed. The performance of the trial product was evaluated on the test bed, ultimately providing a safe evacuation environment if high-rise buildings fired.

关键词： Pressurization System Smoke Control High-Rise Building Evacuation Stairwell Field Experiment

Beta-nerve growth factor gene therapy alleviates pyridoxine-induced neuropathic damage by increasing doublecortin and tyrosine kinase A in the dorsal root ganglion

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2020年第1期15卷 162-168页

作者： hyun-Kee Cho Woosuk Kim Kwon-Young Lee Jin-Ok ahn Jung Hoon Choi In Koo Hwang Jin-Young Chung Department of Veterinary Internal Medicine and Institute of Veterinary Science College of Veterinary MedicineKangwon National UniversityChuncheonKangwon-doSouth Korea Department of Anatomy and Cell Biology College of Veterinary MedicineResearch Institute for Veterinary ScienceSeoul National UniversitySeoulSouth Korea Department of Anatomy College of Veterinary MedicineKangwon National UniversityChuncheonKangwon-doSouth Korea

Beta-nerve growth factor(β-NGF) is known to be a major leading cause of neuronal plasticity. To identify the possible action mechanisms of β-NGF gene therapy for sciatic nerve recovery, experimental dogs were randomly divided into control, pyridoxine, and pyridoxine + β-NGF groups. We observed chronological changes of morphology in the dorsal root ganglia in response to pyridoxine toxicity based on cresyl violet staining. The number of large neurons positive for cresyl violet was dramatically decreased after pyridoxine intoxication for 7 days in the dorsal root ganglia and the neuron number was gradually increased after pyridoxine withdrawal. In addition, we also investigated the effects of β-NGF gene therapy on neuronal plasticity in pyridoxine-induced neuropathic dogs. To accomplish this, tyrosine kinase receptor A(TrkA), βIII-tubulin and doublecortin(DCX) immunohistochemical staining was performed at 3 days after the last pyridoxine treatment. TrkA-immunoreactive neurons were dramatically decreased in the pyridoxine group compared to the control group, but strong TrkA immunoreactivity was observed in the small-sized dorsal root ganglia in this group. TrkA immunoreactivity in the dorsal root ganglia was similar between β-NGF and control groups. The numbers of βIII-tubulin-and DCX-immunoreactive cells decreased significantly in the pyridoxine group compared to the control group. However, the reduction of βIII-tubulin-and DCX-immunoreactive cells in the dorsal root ganglia in the β-NGF group was significantly ameliorated than that in the pyridoxine group. These results indicate that β-NGF gene therapy is a powerful treatment of pyridoxine-induced neuropathic damage by increasing the TrkA and DCX levels in the dorsal root ganglia. The experimental protocol was approved by the Institutional Animal Care and Use Committee(IACUC) of Seoul National University, South Korea(approval No. SNU-060623-1, SNU-091009-1) on June 23, 2006 and October 9, 2009, respectively.

关键词： β-nerve growth factor βIII-tubulin doublecortin gene therapy neuron-glial antigen 2 neuropathy pyridoxine

Graphene-based flexible and wearable electronics

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2018年第1期39卷 86-104页

作者： Tanmoy Das Bhupendra K.Sharma Ajit K.Katiyar Jong-hyun ahn School of Electrical and Electronic Engineering Yonsei University

Graphene with an exceptional combination of electronic, optical and outstanding mechanical features has been proved to lead a completely different kind of 2-D electronics. The most exciting feature of graphene is its ultra-thin thickness, that can be conformally contacted to any kind of rough surface without losing much of its transparency and conductivity. Graphene has been explored demonstrating various prototype flexible electronic applications, however, its potentiality has been proven wherever transparent conductive electrodes（TCEs） are needed in a flexible, stretchable format. Graphene-based TCEs in flexible electronic applications showed greatly superior performance over their conventionally available competitor indium tin oxide（ITO）. Moreover, enormous applications have been emerging, especially in wearable devices that can be potentially used in our daily life as well as in biomedical areas. However, the production of high-quality, defect-free large area graphene is still a challenge and the main hurdle in the commercialization of flexible and wearable products. The objective of the present review paper is to summarize the progress made so far in graphene-based flexible and wearable applications. The current developments including challenges and future perspectives arc also highlighted.

关键词： graphene flexible electronics wearable electronics transparent conductive electrode

Hybrid Friction Stir Welding of High-carbon Steel

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2011年第2期27卷 127-130页

作者： Don-hyun Choi Chang-Yong Lee Byung-Wook ahn Jung-hyun Choi Yun-Mo Yeon Keun Song Seung-Gab Hong Won-Bae Lee Ki-Bong Kang Seung-Boo Jung School of Advanced Materials Science and Engineering Sungkyunkwan University 300 Cheoncheon-dongJangan-guSuwonGyeonggi-do 440-746South Korea Department of Mechanical Engineering Korea Advanced Institute of Science and Technology 335 GwahangnoYuseong-guDaejeon 305-701South Korea Department of Advanced Materials Application Suwon Science College 9-10Botong-liJeongnam-myeonHwasungGyeonggi-do 445-742South Korea Technical Research Lab POSCO Corp.Goedong-dongNam-guPohangGyeongbuk790-785South Korea

A high-carbon steel joint,SK5（0.84 wt% C）,was successfully welded by friction stir welding（FSW）,both without and with a gas torch,in order to control the cooling rate during *** welding,the weld zone comprised gray and black regions,corresponding to microstructural variation：a martensite structure and a duplex structure of ferrite and cementite,*** volume fraction of the martensite structure and the Vickers hardness in the welds were decreased with the using of the gas torch,which was related with the lower cooling rate.

关键词： Friction stir welding High-carbon steel Transformation Martensite

High-frequency magnetic stimulation attenuates beta-amyloid protein 1-42 neurotoxicity in organotypic hippocampal slices

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2010年第18期5卷 1365-1372页

作者： Don-Kyu Kim Young Chul Yoon Soo ahn Chae Kyung Mook Seo Tai Ryoon Han Si-hyun Kang Department of Physical Medicine and Rehabilitation Chung-Ang University College of Medicine Department of Neurology Chung-Ang University College of Medicine Department of Pediatrics Chung-Ang University College of Medicine Department of Physical Medicine and Rehabilitation Seoul National University

Repetitive transcranial magnetic stimulation （rTMS） has been utilized as a therapeutic tool for neurodegenerative disorders including Alzheimer＇s disease. However, the precise mechanisms of its clinical effects remain unknown. β-amyloid （Aβ） exhibits direct neurotoxic effects and is closely related to neuronal degeneration in Alzheimer＇s disease. Therefore, it has been hypothesized that the neuroprotective effects of rTMS are related to the mechanisms of protection against Aβ neurotoxicity. Organotypic hippocampal slices were prepared from 8-day old, Sprague Dawley rats. The tissue slices were exposed to 100 μmol/L Al3142 since day 12 in vitro with and without high-frequency （20 Hz） magnetic stimulation. Magnetic stimulation efficacy was evaluated by measuring neuronal nuclei （NeuN） protein expression and by observing cultures following propidium iodide fluorescence staining and bromodeoxyuridine （BrdU） immunohistochemistry. Lactate dehydrogenase activity was detected in the culture media to evaluate hippocampal neuronal damage. Our results demonstrated that high-frequency magnetic stimulation significantly reversed the reduction of NeuN protein expression because of Aβ1-42 exposure （P 〈 0.05） and significantly reduced the number of damaged cells in the hippocampal slices （P 〈 0.05）. However, lactate dehydrogenase levels and anti-BrdU staining results did not reveal any statistical differences These findings indicate that high-frequency magnetic stimulation might have protective effect on hippocampal neurons from Aβ1-42 neurotoxicity.

关键词： organotypic hippocampus amyloid beta-protein magnetic stimulation nerve degeneration/metabolism nerve degeneration/pathology organ culture techniques rats, Sprague Dawiey

Estimation of effective plant area index for South Korean forests using LiDAR system

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2010年第7期53卷 898-908页

作者： KWAK Doo-ahn LEE Woo-Kyun KAFATOS Menas SON Yowhan CHO hyun-Kook LEE Seung-Ho Department of Environmental Science and Ecological Engineering Korea University Center of Excellence in Earth Observing Schmid College of ScienceChapman University Division of Forest Resources Information Korea Forest Research Institute

Light Detection and Ranging(LiDAR) systems can be used to estimate both vertical and horizontal forest *** components,the leaves of trees and the understory can be described with high precision,using geo-registered *** on this concept,the Effective Plant Area Indices(PAIe) for areas of Korean Pine(Pinus koraiensis),Japanese Larch(Larix leptolepis) and Oak(Quercus spp.) were estimated by calculating the ratio of intercepted and incident LIDAR laser rays for the canopies of the three forest ***,the canopy gap fraction(GLiDAR) was generated by extracting the LiDAR data reflected from the canopy surface,or inner canopy area,using k-means *** LiDAR-derived PAIe was then estimated by using GLIDAR with the Beer-Lambert law.A comparison of the LiDAR-derived and field-derived PAIe revealed the coefficients of determination for Korean Pine,Japanese Larch and Oak to be 0.82,0.64 and 0.59,*** differences between field-based and LIDAR-based PAIe for the different forest types were attributed to the amount of leaves and branches in the forest *** absence of leaves,in the case of both Larch and Oak,meant that the LiDAR pulses were only reflected from *** probability that the LiDAR pulses are reflected from bare branches is low as compared to the reflection from branches with a high leaf *** is because the size of the branch is smaller than the resolution across and along the 1 meter LIDAR laser ***,a better predictive accuracy would be expected for the model if the study would be repeated in late spring when the shoots and leaves of the deciduous trees begin to appear.

关键词： leaf area index plant area index LiDAR k-means clustering gap fraction beer-lambert law

Correlation of Microstructure and Hydrogen Delayed Fracture for 1GPa Steels

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2011年第S1期18卷 252-254页

作者： Hee Jae Kang Ji Tae Park Soon Tae ahn Kyung Mox Cho Nam hyun Kang Department of Materials Science and Engineering Pusan National UniversityBusan 609-735Korea Samhwa Steel 339-4 Samrak-dongSasang-guBusan 617-825Korea

Automobile industry tries to reduce the weight of automobile using high-strength ***,the high-strength steels are highly susceptible to delayed-fracture caused by hydrogen *** increasing the strength,hydrogen embrittlement is more sensitive to diffusible *** mechanism of delayed-fracture and the relationship with the microstructure and alloying elements are still *** study analyzed the effect of the size and the spheroidization rate for the carbides on hydrogen-induced delayed fracture for 1GPa TS steel.

关键词： hydrogen delayed fracture microstructure spheroidization

Microbiology and risk factors for gram-positive Cocci bacteremia in biliary infections

在线全文

学校读者我要写书评

暂无评论

Hepatobiliary & Pancreatic Diseases International 2020年第5期19卷 461-466页

作者： Ik hyun Jo Yeon-Ji Kim Woo Chul Chung Jaeyoung Kim Seonhoo Kim Eun Sun Lim Honggeun ahn Seong Yul Ryu Division of Gastroenterology Department of Internal MedicineSt.Vincent’s HospitalCollege of MedicineThe Catholic University of KoreaSuwon 16247Korea

Background:The rapid antibiotics treatment targeted to a specific pathogen can improve clinical outcomes of *** aimed to evaluate the clinical characteristics and outcomes of biliary septicemia caused by cholangitis or cholecystitis according to causative ***:We performed a retrospective cohort study in 151 patients diagnosed with cholangitis or cholecystitis with bacterial septicemia from January 2013 to December *** patients showed clinical evidence of biliary tract infection and had blood isolates that demonstrated ***:Gram-negative,gram-positive,and both types of bacteria caused 84.1%(127/151),13.2%(20/151),and 2.6%(4/151)episodes of septicemia,*** most common infecting organisms were Escherichia coli among gram-negative bacteria and Enterococcus species(Enterococcus casseliflavus and Enterococcus faecalis)among gram-positive *** were no differences in mortality,re-admission rate,and need for emergency decompression procedures between the gram-positive and gram-negative septicemia *** univariate analysis,previous gastrectomy history was associated with gram-positive *** analysis also showed that previous gastrectomy history was strongly associated with gram-positive septicemia(Odds ratio=5.47,95%CI:1.19–25.23;P=0.029).Conclusions:Previous gastrectomy history was related to biliary septicemia induced by gram-positive *** information would aid the choice of empirical antibiotics.

关键词： Cholangitis Cholecystitis Septicemia Gram-positive bacterial infections

Bojungbangdocktang inhibits vascular endothelial growth factor induced angiogenesis via blocking the VEGF/VEGFR2 signaling pathway in human umbilical vein endothelial cells

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2009年第2期54卷 227-233页

作者： JANG Yu-Sung LEE Eun-Ok LEE Hyo-Jung LEE Hyo-Jeong KIM Kwan-hyun WON Sook-hyun LEE Jae-Dong ahn Kwang Seok ahn Kyoo Seok KIM Jung-Hyo YU Young-Beob KIM Sung-Hoon College of Oriental Medicine Kyunghee University 1 Hoegidong Dongdaemungu Seou1130-701 Republic of Korea Chosun Nursing College 375 Seosuk-dong Dong-gu Gwangju 501-759 Korea Department of Herbal Pharmaceutical Korea Institute of Oriental Medicine Jeonmin dong Youseonggu Daejeon 305-811 Republic of Korea

Oriental herbal medicines have been widely used for the prevention or treatment of various diseases including cancer in Asia. However, to prove their chemo preventive efficacies in modern times, scientific evidence for those herbal medicines is required. Thus, in the present study, an effective herbal cocktail Bojungbangdocktang (BJBDT) was investigated to elucidate antiangiogenic mechanism in vitro and in vivo. BJBDT significantly inhibited vascular endothelial growth factor (VEGF) induced proliferation in HUVECs at nontoxic concentrations, despite weak cytotoxicity against human umbilical vein endothelial cells (HUVECs). BJBDT also significantly suppressed VEGF-induced migration and tube formation of HUVECs. Furthermore, BJBDT treatment resulted in pale color and low hemoglobin level in Matrigel plugs, as well as dark red color and high hemoglobin level in untreated control. Interestingly, BJBDT specifically inhibited the binding of VEGF to vascular endothelial growth factor receptor 2 (VEGFR2), but not VEGFR1. In addition, friedelin, formononetin, ginsenoside Rb1, naringin, atractyloside, diosgenin, and allantonin were identified from BJBDT by high-performance liquid chromatography (HPLC) analysis as a quality of control. Taken together, these results suggest that BJBDT is a potent angiogenesis inhibitor blocking the VEGF/VEGFR2 signaling pathway in HUVECs.

关键词：血管新技术人大动脉内皮细胞 HUVECs VEGFR2

Nuclear and chloroplast genome diversity revealed by low-coverage whole-genome shotgun sequence in 44 Brassica oleracea breeding lines

在线全文

学校读者我要写书评

暂无评论

Horticultural Plant Journal 2021年第6期7卷 539-551页

作者： Sampath Perumal Nomar Espinosa Waminal Jonghoon Lee hyun-Jin Koo Boem-soon Choi Jee Young Park Kyounggu ahn Tae-Jin Yang Department of Agriculture Forestry and BioresourcesPlant Genomics and Breeding Instituteand Research Institute of Agriculture and Life SciencesCollege of Agriculture and Life SciencesSeoul National UniversitySeoul 08826Republic of Korea Global Institute for Food Security University of Saskatchewan421 Downey RoadSaskatoonSK S7N 4L8Canada Agriculture and Agri-Food Canada 107 Science PlaceSaskatoon S7N 0X2Canada Chromosome Research Institute Department of Life ScienceSahmyook UniversitySeoul 01795Republic of Korea Joeun Seeds.Co. LtdGoesan-GunChungcheongbuk-Do 367-833Republic of Korea Phyzen Genomics Institute 13Seongnam-daero 331beon-gilBundang-guSeongnam-siGyeonggi-do 13558Republic of Korea

Whole-genome shogun sequence(WGS)data generated by next-generation sequencing(NGS)platforms are a valuable resource for crop *** produced 5–6×WGS coverage of 44 Brassica oleracea breeding lines representing seven subspecies/morphotypes:cabbage,broccoli,cauliflower,kailan,kale,Brussels sprout,and kohlrabi to systematically evaluate the nuclear and chloroplast(Cp)diversity in the 44 *** breeding *** then exploited the impact of low-coverage NGS by evaluating nuclear genome diversity and assembly,annotation of complete chloroplast(Cp)genomes and 45 S nuclear ribosomal DNA(45S nrDNA)sequences,and copy number variation for major *** genome diversity analysis has revealed a total of 496463 SNPs and 37493 indels in the nuclear genome across the 44 ***,some SNPs showed subspecies enrichment at certain chromosomal *** assembly of complete Cp genomes contained 153361–153372 bp with 37 variants including SNPs and *** 45S nrDNA transcription unit was 5802 bp long with a total of 31 SNPs from the 44 *** phylogenetic tree inferred from the nuclear and Cp genomes coincided and clustered broccoli,cauliflower,and kailan in one group and cabbage,Brussels sprout,kale,and kohlrabi in another *** morphotypes diverged during the last 0.17 million *** Cp genome diversity reflected the unique cytoplasm of each subspecies,and revealed that the cytoplasm of many breeding lines was replaced and intermingled via inter-subspecies crosses during the breeding process *** polymorphic Cp markers provide a classification system for the cytoplasm types in ***,copy numbers of major transposable elements(TEs)showed high diversity among the 44 accessions,indicating that many TEs have become active ***,we demonstrated a comprehensive utilization of low-coverage NGS data and might shed light on the genetic diversity and evolution of diverse *** morphotypes.

关键词： Brassica oleracea subspecies Chloroplast genome Nuclear ribosomal DNA Genetic diversity Phylogeny