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Recent Progress and Development in Extrusion of Rare Earth Free Mg Alloys: A Review

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Acta Metallurgica Sinica(English Letters) 2019年第2期32卷 145-168页

作者： Shuai-Ju Meng Hui Yu Shao-Da Fan Qi-Zhi Li Sung Hyuk park Joung Sik Suh young min Kim Xiao-Long Nan ming-Zhe Bian Fu-Xing Yin Wei-min Zhao Bong Sun You Kwang Seon Shin School of Materials Science and Engineering Hebei University of Technology School of Materials Science and Engineering Kyungpook National University Materials Implementation Department Korea Institute of Materials Science National Key Laboratory of Shock Wave and Detonation Physics Institute of Fluid Physics China Academy of Engineering Physics School of Materials Science and Engineering Anhui University of Technology Magnesium Technology Innovation Center School of Materials Science and Engineering Seoul National University

Mg and its alloys are the lightest structural metals available and are extremely attractive for applications as lightweight components, particularly in the automobile, electronic, and aerospace industries. The global market for wrought Mg alloys has steadily expanded over the past decade. And numerous studies have been carried out to meet this increasing demand of high-performance Mg alloys. However, Mg extrusion alloys have had a very limited usage so far. To overcome existing industrial challenges, one desirable approach is the development of low-cost rare earth(RE) free Mg extrusion alloys with superior mechanical properties. This review will introduce the recent research highlights in the extrusion of Mg alloys, specifi cally focusing on low-cost RE-free Mg alloy. The results from both the literature and our previous study are summarized and critically reviewed. Several aspects of RE-free Mg extrusion alloys are described in detail:(1) novel alloying designs including Mg–Al-, Mg–Zn-, Mg–Ca-, Mg–Sn-, and Mg–Bi-based alloys,(2) advanced extrusion techniques, and(3) extrusion-related severe plastic deformation(SPD) processing. Accordingly, considering the large gap in mechanical properties between the current RE-free Mg alloys and high-performance aluminum alloys, new alloy design, processing route control, and recommendations for future research on RE-free Mg extrusion alloys are also proposed. We hope this review will not only off er insightful information regarding the extrusion of RE-free Mg alloys but also inspire the development of new Mg extrusion technologies.

关键词： Mg alloy Extrusion Rare earth free Novel processing Mechanical properties

Review of MXenes as new nanomaterials for energy storage/delivery and selected environmental applications

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Nano Research 2019年第3期12卷 471-487页

作者： Byung-Moon Jun Sewoon Kim Jiyong Heo Chang min park Namguk Her min Jang Yi Huang Jonghun Han Yeomin Yoon Department of Civil and Environmental Engineering University of South Carolina Columbia 300 Main Street SC 29208 USA Department of Civil and Environmerttal Engineering Korea Army Academy at Young-Cheon 495 Hogook-ro Kokyungmeon Young-Cheon Gyeongbuk 38900 Republic of Korea Department of Environmental Engineering Kyungpook National University 80 Daehak-ro Buk-gu Daegu 41566 Republic of Korea Department of Environmental Engineering Kwangwoon University 447-1 Wolgye-Dong Nowon-Gu Seoul 01897 Republic of Korea School of Engineering Institute for Materials & Processes (IMP) The University of Edinburgh Colin Maclaurin Road Edinburgh EH9 3DW Scotland UK

Energy and environmental issues presently attract a great deal of scientific attention. Recently, two-dimensional MXenes and MXene-based nanomaterials have attracted increasing interest because of their unique properties (e.g., remarkable safety, a very large interlayer spacing, environmental flexibility, a large surface area, and thermal conductivity). In 2011, multilayered MXenes (Ti3C2Tx, a new family of two-dimensional (2D) materials) produced by etching an A layer from a MAX phase of Ti3AlC2, were first described by researchers at Drexel University. The term “MXene” was coined to distinguish this new family of 2D materials from graphene, and applies to both the original MAX phases and MXenes fabricated from them. We present a comprehensive review of recent studies on energy and environmental applications of MXene and MXene-based nanomaterials, including energy conversion and storage, adsorption, membrane, photocatalysis, and antimicrobial. Future research needs are discussed briefly with current challenges that must be overcome before we completely understand the extraordinary properties of MXene and MXene-based nanomaterials.

关键词： MXenes MXene-based nanomaterials energy storage environment applications

Restoration of common bile duct diameter within 2 weeks after endoscopic stone retraction is a preventive factor for stone recurrence

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Hepatobiliary & Pancreatic Diseases International 2018年第3期17卷 251-256页

作者： Jin Jeon Sung Uk Lim Chang-Hwan park Chung-Hwan Jun Seon-young park Jong-Sun Rew Department of Internal Medicine Chonnam National University Hospital Department of Internal Medicine Mokpo Hankook Hospital

Background： Little information is available about the relationship between restoration of common bileduct （CBD） diameter after endoscopic stone retraction and recurrence of CBD stones in elderly *** present study was to determine whether restoration of CBD diameter is a preventive factor for CBDstone recurrence in elderly patients who underwent endoscopic retrograde cholangiopancreatography（ERCP）.

关键词： Restoration Common bile duct Endoscopic retrograde cholangiopancreatography Common bile duct stone

Time- and cell-type specific changes in iron, ferritin, and transferrin in the gerbil hippocampal CA1 region after transient forebrain ischemia

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Neural Regeneration Research 2016年第6期11卷 924-930页

作者： Dae young Yoo Ki-Yeon Yoo Joon Ha park Hyun Jung Kwon Hyo young Jung Jong Whi Kim Goang-min Choi Seung Myung Moon Dae Won Kim Yeo Sung Yoon Moo-Ho Won In Koo Hwang Department of Anatomy and Cell Biology College of Veterinary Medicine and Research Institute for Veterinary Science Seoul National University Department of Oral Anatomy Research Institute of Oral Sciences College of Dentistry Gangneung-Wonju National University Department of Neurobiology School of Medicine Kangwon National University Department of Biochemistry and Molecular Biology Research Institute of Oral Sciences College of Dentistry Gangneung-Wonju National University Department of Thoracic and Cardiovascular Surgery Chuncheon Sacred Heart Hospital College of Medicine Hallym University Department of Neurosurgery Dongtan Sacred Heart Hospital College of Medicine Hallym University

In the present study, we used immunohistochemistry and western blot analysis to examine changes in the levels and cellular localization of iron, heavy chain ferritin（ferritin-H）, and transferrin in the gerbil hippocampal CA1 region from 30 minutes to 7 days following transient forebrain ischemia. Relative to sham controls, iron reactivity increased significantly in the stratum pyramidale and stratum oriens at 12 hours following ischemic insult, transiently decreased at 1–2 days and then increased once again within the CA1 region at 4–7 days after ischemia. One day after ischemia, ferritin-H immunoreactivity increased significantly in the stratum pyramidale and decreased at 2 days. At 4–7 days after ischemia, ferritin-H immunoreactivity in the glial components in the CA1 region was significantly increased. Transferrin immunoreactivity was increased significantly in the stratum pyramidale at 12 hours, peaked at 1 day, and then decreased significantly at 2 days after ischemia. Seven days after ischemia, Transferrin immunoreactivity in the glial cells of the stratum oriens and radiatum was significantly increased. Western blot analyses supported these results, demonstrating that compared to sham controls, ferritin H and transferrin protein levels in hippocampal homogenates significantly increased at 1 day after ischemia, peaked at 4 days and then decreased. These results suggest that iron overload-induced oxidative stress is most prominent at 12 hours after ischemia in the stratum pyramidale, suggesting that this time window may be the optimal period for therapeutic intervention to protect neurons from ischemia-induced death.

关键词： ferritin transferrin hippocampal stratum minutes glial Ferritin hippocampus rabbit reactivity

Weekend and nighttime effect on the prognosis of peptic ulcer bleeding

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World Journal of Gastroenterology 2012年第27期18卷 3578-3584页

作者： young Hoon Youn Yong Jin park Jae Hak Kim Tae Joo Jeon Jae Hee Cho Hyojin park Department of Internal Medicine Gangnam Severance HospitalYonsei University College of MedicineSeoul 135-720South Korea Department of Internal Medicine Dongguk University Ilsan HospitalDongguk University College of MedicineGyeonggi-do 410-773South Korea Department of Internal Medicine Inje University Sanggye Paik HospitalInje University College of MedicineSeoul 139-707South Korea Department of Internal Medicine Kwandong University Myungji HospitalKwandong University College of MedicineGyeonggi-do 412-270South Korea

AIM:To evaluate whether weekend or nighttime admission affects prognosis of peptic ulcer bleeding despite early ***:Retrospective data collection from four referral centers,all of which had a formal out-of-hours emergency endoscopy service,even at weekends.A total of 388 patients with bleeding peptic ulcers who were admitted via the emergency room between January 2007 and December 2009 were *** parameters included time from patients' arrival until endoscopy,mortality,rebleeding,need for surgery and length of hospital ***:The weekday and weekend admission groups comprised 326 and 62 patients,*** were no significant differences in baseline characteristics between the two groups,except for younger age in the weekend *** patients (97%) had undergone early endoscopy,which resulted in a low mortality rate regardless of point of presentation (1.8% overall vs 1.6% on the weekend).The only outcome that was worse in the weekend group was a higher rate of rebleeding (12% vs 21%,P = 0.030).However,multivariate analysis revealed nighttime admission and a high Rockall score (≥ 6) as significant independent risk factors for rebleeding,rather than weekend ***:Early endoscopy for peptic ulcer bleeding can prevent the weekend effect,and nighttime admission was identified as a novel risk factor for rebleeding,namely the nighttime effect.

关键词： Early endoscopy Nighttime effect Pepticulcer bleeding Rebleeding Weekend effect

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World Journal of Gastroenterology 2008年第27期14卷 4359-4364页

作者： young Hye Byun Jun Haeng Lee Moon Kyung park Ji Hyun Song Byung-Hoon min Dong Kyung Chang young- Ho Kim Hee Jung Son Poong-Lyul Rhee Jae J Kim Jong Chul Rhee Ji Hye Hwang Dong Il park Sang Goon Shim In Kyung Sung Department of Medicine Sungkyunkwan University School of Medicine Samsung Medical Center Department of Physical Medicine and Rehabilitation Sungkyunkwan University School of Medicine Samsung Medical Center Department of Medicine Sungkyunkwan University School of Medicine Kangbuk Samsung Hospital Department of Medicine Sungkyunkwan University School of Medicine Masan Samsung Hospital Department of Internal Medicine Konkuk University College of Medicine

AIM: To determine the prevalence and risk factors of work-related musculoskeletal disorders in gastrointestinal endoscopists in Korea. METHODS: A survey of musculoskeletal symptoms, using a self-administered questionnaire, was conducted on 55 endoscopists practicing in general hospitals or health promotion centers. RESULTS: Forty-nine (89.1%) endoscopists reported musculoskeletal pain on at least one anatomic location and 37 (67.3%) endoscopists complained of pain at rest. Twenty-six (47.3%) endoscopists had severe musculoskeletal pain defined as a visual analogue score greater than 5.5. Factors related to the development of severe pain were (1) standing position during upper endoscopy, (2) specific posture/ habit during endoscopic procedures, and (3) multiple symptomatic areas. Finger pain was more common in beginners, whereas shoulder pain was more common in experienced endoscopists. Sixteen percent of symptomatic endoscopists have modified their practice or reduced the number of endoscopic examinations. Only a few symptomatic endoscopists had sought professional consultation with related specialists. CONCLUSION: The prevalence of musculoskeletal pain in endoscopists is very high. The location of pain was different between beginners and experienced endoscopists. Measures for the prevention and adequate management of endoscopy-related musculoskeletal symptoms are necessary.

关键词： Endoscopy Endoscopist Musculoskeletal symptom

Improving high-temperature oxidation behavior by modifying Al and Co content in Al-Co-Cr-Fe-Ni high-entropy alloy

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Journal of Materials Science & Technology 2022年第34期129卷 115-126页

作者： Timothy Alexander Listyawan Maya Putri Agus tianingrum young Sang Na Ka Ram Lim Nokeun park School of Materials Science and Engineering Yeungnam University280 Daehak-roGyeongbuk 38541Republic of Korea Advanced Metals Division Korea Institute of Materials Science(KIMS)797 ChangwondaeroSeongsan-guChangwonGyeongnam 51508Republic of Korea Institute of Materials Technology Yeungnam University280 Daehak-roGyeongsanGyeongbuk 38541Republic of Korea

Composition modification was introduced to improve the oxidation resistance by varying Al and excluding Co from the Al-Co-Cr-Fe-Ni system. Since adjusting the composition shifted the valence electron concentration(VEC) of the alloys, the dual-phase structure of the alloys is expected to be more stable. At low temperatures(T minated the alloy’s surface. Compared to equiatomic AlCoCrFeNi(5-Equi), nonequiatomic AlCoCrFeNi(5-B 40) and four-component AlCrFeNi(4-B 2013) had better oxidation resistance due to monocrystalline-Al_(2)O_(3)formation. Besides the role of oxide formation, maintaining BCC and B2phases within the alloys is also beneficial to supporting the stable Cr_(2)O_(3)or Al_(2)O_(3).

关键词： High-entropy alloy Alloy design Oxidation Valence electron concentration Phase stability Transmission electron microscope

Polymyxin B hemoperfusion as a feasible therapy after source control in abdominal septic shock

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World Journal of Gastrointestinal Surgery 2019年第12期11卷 422-432页

作者： Jin Joo Kim young Jun park Ki Yoon Moon Jin Hyeong park Yong Ki Jeong Eun young Kim Division of Trauma and Surgical Critical Care Department of Surgery Seoul St. Mary’s Hospital College of Medicine The Catholic University of Korea

BACKGROUND Polymyxin B hemoperfusion(PMX-HP)has been used as a treatment for intraabdominal septic shock by absorbing and removing endotoxins of gram-negative *** To investigate the clinical efficacy of PMX-HP in patients with gram-negative septic shock who underwent abdominal *** From January 2012 to December 2018,patients who had septic shock secondary to peritonitis were *** were classified into PMX-HP treated and control groups based on postopreative intervention using *** clinical outcomes were compared using 1:1 propensity score matching methods to balance the overall distribution between the two *** After propensity score matching,40 patients were analyzed(20 patients in the PMX group and 20 patients in the control group).The scores of total Sequential Organ Failure Assessment(SOFA)score,renal SOFA and coagulation SOFA were significantly improved in the PMX group but not in the control group.(from 11.2±5.8 to 4.7±3.5 in PMX group vs 10.0±4.0 to 8.7±7.3 in control group,P=0.047 from 2.6±1.0 to 0.7±1.0 in PMX group vs 2.6±1.5 to 2.8±1.6 in control group,P=0.000,from 1.6±1.5 to 1.3±1.3 in PMX group vs 1.2±1.2 to 2.8±1.8 in control group,P=0.014,respectively).Further,the length of intensive care unit(ICU)stay was significantly shorter in PMX ***,no statistically significant difference was found in ICU mortality(50%in PMX group vs 50%in control group).CONCLUSION PMX-HP is a feasible adjunct treatment for peritonitis in ICU patients with peritonitis for improved organ impairment and to stabilize *** would be helpful to enhance clinical outcomes especially in patients with complete elimination of the source of gram-negative bacilli infection by surgical procedure accompanied with conventional treatment of sepsis.

关键词： Intraabdominal septic shock Panperitonitis Polymyxin B hemoperfusion Sepsis Toraymyxin

Enhancement of Au–Ag–Te contents in tellurium-bearing ore minerals via bioleaching

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International Journal of minerals,Metallurgy and Materials 2018年第3期25卷 262-270页

作者： Nag-Choul Choi Kang Hee Cho Bong Ju Kim Soonjae Lee Cheon young park Department of Rural Systems Engineering Seoul National University Department of Earth and Environmental Sciences Korea University Department of Energy and Resource Engineering Chosun University

The purpose of this study was to enhance the content of valuable metals, such as Au, Ag, and Te, in tellurium-bearing minerals via bioleaching. The ore samples composed of invisible Au and Au paragenesis minerals(such as pyrite, chalcopyrite, sphalerite and galena) in combination with tellurium-bearing minerals(hessite, sylvanite and Tellurobismuthite) were studied. Indigenous microbes from mine drainage were isolated and identified as Acidithiobacillus ferrooxidans, which were used in bioleaching after adaption to copper. The effect of the microbial adaption on the bioleaching performance was then compared with the results produced by the non-adaptive process. The microbial adaption enhanced the Au–Ag–Te contents in biological leaching of tellurium-bearing ore minerals. This suggests that bioleaching with adapted microbes can be used both as a pretreatment and in the main recovery processes of valuable metals.

关键词： tellurium-bearing mineral bioleaching adaptation Au–Ag–Te Acidithiobacillus ferrooxidans