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Molecular mechanisms and cellular process in signal transduction pathway related to air pollutants in obstructive lung diseases:A mini-review

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BIOCELL 2023年第8期47卷 1703-1708页

作者： AN-soo jang Division of Allergy and Respiratory Medicine Department of Internal MedicineSoonchunhyang University Bucheon Hospital170 Jomaru-roBucheon-siGyeonggi-do14584Korea

Exposure to air pollutants such as PM_(10),PM_(2.5),PM_(0.1),O_(3),CO,NO2,and SO_(2),and biological pollutants are important factors causing the evolution and furtherance of obstructive lung diseases(OLD),including asthma and chronic obstructive pulmonary disease(COPD).Asthma is the most frequent chronic inflammatory airway disease,characterized by breathlessness,wheezing,chest tightness,and cough,together with the presence of exaggerated expiratory airflow fluctuation that varies over *** is a heterogeneous lung condition characterized by chronic respiratory symptoms such as dyspnea,cough,expectoration,and/or exacerbations due to abnormalities of the airways and/or alveoli that cause persistent,often progressive,airflow *** the molecular mechanisms and cellular processes based on the development of OLD on exposure to air pollutants will provide insights into the solution of pathogenesis,prevention,and treatment of these *** molecular mechanisms and cellular process involved in signal transduction pathway plays a role in the binding of extracellular signaling molecules and ligands to receptors placed on the cell surface or on the inner side cell that trigger inflammation that occurs,especially when something important enters the cell to bring into a cascade *** binding then alters the cell metabolism,shape,and gene expression in the *** review aimed to reveal the effect of air pollutants on the molecular mechanisms and cellular processes involved in the signal transduction pathways in OLD.

关键词： Air pollutants Obstructive lung diseases Signal pathway

Dual-frequency piezoelectric micromachined ultrasound transducer based on polarization switching in ferroelectric thin films

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Microsystems & Nanoengineering 2023年第5期9卷 233-243页

作者： Jin soo Park soo Young Jung Dong Hun Kim Jung Ho Park Ho Won jang tae Geun Kim Seung-Hyub Baek Byung Chul Lee Bionics Research Center Korea Institute of Science and TechnologySeoul 02792Republic of Korea Department of Electrical Engineering Korea UniversitySeoul 02841Republic of Korea Center for Electronic Materials Korea Institute of Science and TechnologySeoul 02792Republic of Korea Department of Material Science and Engineering Seoul National UniversitySeoul 08826Republic of Korea Division of Bio-Medical Science and Technology KIST SchoolUniversity of Science and Technology(UST)Seoul 02792Republic of Korea KHU-KIST Department of Converging Science and Technology Kyung Hee UniversitySeoul 02447Republic of Korea

Due to its additional frequency response,dual-frequency ultrasound has advantages over conventional ultrasound,which operates at a specific frequency ***,a tunable frequency from a single transducer enables sonographers to achieve ultrasound images with a large detection area and high *** facilitates the availability of more advanced techniques that simultaneously require low-and high-frequency ultrasounds,such as harmonic imaging and image-guided *** this study,we present a novel method for dual-frequency ultrasound generation from a ferroelectric piezoelectric micromachined ultrasound transducer(PMUT).Uniformly designed transducer arrays can be used for both deep low-resolution imaging and shallow high-resolution *** switch the ultrasound frequency,the only requirement is to tune a DC bias to control the polarization state of the ferroelectric *** vibration of the PMUT membrane strongly depends on the polarization state,producing low-and high-frequency ultrasounds from a single excitation *** strategy for dual-frequency ultrasounds meets the requirement for either multielectrode configurations or heterodesigned elements,which are integrated into an ***,this technique significantly reduces the design complexity of transducer arrays and their associated driving circuits.

关键词： piezoelectric ferroelectric enable

Velocity Profiles between Two Baffles in a Shell and Tube Heat Exchanger

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Journal of Thermal Science 2015年第4期24卷 356-363页

作者： tae-Hyun Chang Chang-Hoan Lee Hae-soo Lee Kwon-soo Lee Senior Research Fellow of RESEAT Korea Institute of Science and Technology Information Korea Institute of Science and Technology Information Postdoctoral Research Fellow School of Mechanical Engineering of Kyungnam University International University of Korea

Heat exchangers are extensively utilized for waste heat recovery,oil refining,chemical processing,and steam *** this study,velocity profiles are measured using a 3D particle image velocimetry(PIV)system between two baffles in a shell and tube heat exchanger for parallel and counter *** PIV and computational fluid dynamics results show the occurrence of some strong vectors near the *** vectors are assumed due to the clearance between the inner tubes and the front ***,the major parts of the vectors are moved out through the bottom opening of the rear baffle,and other vectors produce a large circle between the two *** simulations are conducted to investigate the effects of the baffle on the heat exchanger using the Fluent *** k-εturbulence model is employed to calculate the flows along the heat exchanger.

关键词： Baffle P1V Shell and tube heat exchanger Cut off ratio CFD

Chemoresistive materials for electronic nose:Progress,perspectives,and challenges

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InfoMat 2019年第3期1卷 289-316页

作者： Seo Yun Park Yeonhoo Kim taehoon Kim tae Hoon Eom soo Young Kim Ho Won jang Department of Materials Science and Engineering Research Institute of Advanced MaterialsSeoul National UniversitySeoulRepublic of Korea Center for Integrated Nanotechnologies Los Alamos National LaboratoryLos AlamosNew Mexico School of Chemical Engineering and Materials Science Chung-Ang UniversitySeoulRepublic of Korea

An electronic nose(e-nose)is a device that can detect and recognize odors and flavors using a sensor *** has received considerable interest in the past decade because it is required in several areas such as health care,environmental monitoring,industrial applications,automobile,food storage,and ***,there are still obstacles in developing a portable e-nose that can be used for a wide variety of *** practical applications of an e-nose,it is necessary to collect a massive amount of data from various sensing materials that can transduce interactions with molecules reliably and analyze them via pattern *** addition,the possibility of miniaturizing the e-nose and operating it with low power consumption should be ***,it should work efficiently over a long period of *** satisfy these requirements,several different chemoresistive material platforms including metal oxides,organics such as polymers and carbonbased materials,and two-dimensional materials were investigated as sensor elements for an *** an individual material has limited selectivity,there is a continuing effort to improve the selectivity and gas sensing properties through surface decoration and compositional and structural *** produce a reliable e-nose,which can be used for practical applications,researches in various fields have to be *** paper reviews the progress of research on e-noses based on a chemoresistive gas sensor array and discusses the inherent challenges and potential solutions.

关键词： chemoresistive materials electronic nose metal oxides polymers two-dimensional materials

Generation of mesenchymal stem-like cells for producing extracellular vesicles

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World Journal of Stem Cells 2019年第5期11卷 270-280页

作者： soo Kim tae Min Kim Brexogen Research Center Brexogen Inc. Seoul Songpa-gu 05718 South Korea Graduate School of International Agricultural Technology and Institute of Green- Bio Science and Technology Seoul National University Gangwon-do Pyeongchang 25354 South Korea

Mesenchymal stem cells (MSCs) are multipotent progenitor cells with therapeutic potential against autoimmune diseases, inflammation, ischemia, and metabolic disorders. Contrary to the previous conceptions, recent studies have revealed that the tissue repair and immunomodulatory functions of MSCs are largely attributed to their secretome, rather than their potential to differentiate into desired cell types. The composition of MSC secretome encompasses cytokines and growth factors, in addition to the cell-derived structures known as extracellular vesicles (EVs). EVs are membrane-enclosed nanoparticles that are capable of delivering biomolecules, and it is now believed that MSC-derived EVs are the major players that induce biological changes in the target tissues. Based on these EVs’ characteristics, the potential of EVs derived from MSC (MSC-EV) in terms of tissue regeneration and immune modulation has grown during the last decade. However, the use of MSCs for producing sufficient amount of EVs has not been satisfactory due to limitations in the cell growth and large variations among the donor cell types. In this regard, pluripotent stem cells (PSCs)-derived MSC-like cells, which can be robustly induced and expanded in vitro, have emerged as more accessible cell source that can overcome current limitations of using MSCs for EV production. In this review, we have highlighted the methods of generating MSC-like cells from PSCs and their therapeutic outcome in preclinical studies. Finally, we have also discussed future requirements for making this cell-free therapy clinically feasible.

关键词： Mesenchymal stem cells Extracellular vesicles Preclinical studies Exosomes

Pancreatic parenchymal injection of ethanol and octreotide to induce focal pancreatic fibrosis in rats: Strategies to eliminate postoperative pancreatic fistula

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Hepatobiliary & Pancreatic Diseases International 2018年第1期17卷 81-85页

作者： soo Ho Lee tae Ho Hong Department of Surgery Uijeongbu St.Mary’s Hospital College of Medicine The Catholic University of Korea Department of Surgery Seoul St.Mary’s Hospital College of Medicine The Catholic University of Korea

Background: Postoperative pancreatic fistula(POPF) is more likely to occur in a soft pancreas compared to a hard pancreas in which fibrosis has progressed. There is almost no leakage at the anastomosis site or cut surface of a hard pancreas. The aim of this study was to induce localized fibrosis at the cut surface of the pancreas in a rat ***: Thirty-six rats were divided into three groups(group S: normal saline group; group E: ethanol group; and group O: octreotide group). Each rat was directly injected with a particular compound at the duodenal lobe of the pancreatic parenchyma. Each group was divided into three subgroups according to the time of post-injection sacrifice(1, 2, or 4 weeks). The hardness, suture holding capacity(SHC), and histological fibrosis grade of each pancreas were ***: The hardness, SHC, and fibrosis grade of groups E and O were increased at week 1, with greater increases in group E(all P < 0.001). In a subgroup comparison, the hardness, SHC, and fibrosis grade of group E tended to decrease gradually over time, with no regular pattern evident in group O. A comparison between the injected site(duodenal lobe) and non-injected site(splenic lobe) of the pancreas revealed increases in the three parameters of group E only in the duodenal lobe, with increases in group O at both the duodenal and splenic ***: Parenchymal injection of ethanol and octreotide increased pancreatic fibrosis. Unlike octreotide, ethanol provoked localized fibrosis that was maintained over time. It is expected that ethanol injection could eliminate POPF during pancreatic surgery.

关键词： Ethanol Octreotide Pancreatic fibrosis Pancreatic fistula Rat model

Environmental friendly synthesis of hierarchical mesoporous platinum nanoparticles templated by fucoidan biopolymer for enhanced hydrogen evolution reaction

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Journal of Materials Science & Technology 2020年第11期42卷 185-190页

作者： Seung Man Lim Kyunglee Kang Hongje jang Jung tae Park Department of Chemical Engineering Konkuk University120 Neungdong-roGwangjin-guSeoul 05029Republic of Korea Department of Chemistry Kwangwoon University20 Cwangwoon-roNowon-guSeoul 01897Republic of Korea

Researching novel hydrogen evolution reaction(HER)catalysts with enhanced electrocatalytic activity,excellent stability,and cost-efficiency is of great significance for the large-scale hydrogen production from industrial electrolysis *** report the preparation of hierarchical mesoporous-Pt nanoparticles(HM-Pt NPs)with coral-like rough surface morphologies using environmental friendly and biocompatible fucoidan(Fu)biopolymer as a surface engineering compound and its application to electrocatalysts for *** designed HM-Pt NPs yields better mass activity of electrocatalysts compared to a commercial Pt/***-Pt NPs showed an overpotential of 33 mV at 10 mA cm-2 for the HER in 0.5 MH2SO4,which was highly comparable to that of the commercial Pt/C catalysts(29 mV).However,the amount of HM-Pt NPs loaded in glassy carbon electrode(0.033 mg mL-1)was approximately 20 times lower than that of the commercial Pt/C(0.64 mg *** HM-Pt NPs also maintained high catalytic stability with a consistent HER current density after 1000 continuous *** excellent HER performance is attributed to the improved electrochemical surface area,highly porous structure,and good surface wettability of the HM-Pt NPs,which results in enhanced electrocatalytic activity,decreased resistance at the electrode/electrolyte interface,and facile penetration of the electrolytes inside the electrode.

关键词： Mesoporous Fucoidan Biopolymer Low Pt content Hydrogen evolution reaction

Ultimate strength of single shear bolted connections with cold-formed ferritic stainless steel

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第2期14卷 120-136页

作者： Jin-seong LIM tae-soo KIM Seung-hun KIM Department of Architectural Engineering Hanbat National UniversityDaejeon 305-719Korea

This paper is focused on the structural behavior of the single shear bolted connections with thin-walled ferritic stainless *** purpose of this study is to investigate the ultimate behaviors,such as ultimate strength and fracture mode of the single shear bolted connections of thin-walled ferritic stainless steel(low cost steel) rather than austenitic stainless steel(high cost steel).Bolt arrangement and end distance parallel to the direction of applied load are considered as main variables of the test specimens for bolted *** have a constant dimension of edge distance perpendicular to the loading direction,bolt diameter,pitch,and gauge.A monotonic tensile test for specimens has been carried out and some bolted connections with long end distance showed curling(out of plane deformation) occurrence which led to strength *** ultimate behaviors such as fracture mode,ultimate strength are compared with those predicted by current design ***,conditions of curling occurrence and the strength reduction due to curling are investigated and modified strength equations are suggested considering the curling effect.

关键词： Cold-formed ferritic stainless steel Bolted connection Bolt arrangement End distance Curling Strength reduction

Endovascular treatment of a ruptured pseudoaneurysm of the internal carotid artery in a patient with nasopharyngeal cancer:A case report

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World Journal of Clinical Cases 2022年第25期10卷 9121-9126页

作者： Jung-soo Park Hyoung Gyu jang Department of Neurosurgery Jeonbuk National University Medical School and HospitalJeonju 54907South Korea

BACKGROUND Radiation therapy(RT)for nasopharyngeal cancer can cause several *** rare cases,an internal carotid artery pseudoaneurysm can occur,which can be *** report the experience of a nasopharyngeal cancer patient who underwent radiation therapy and subsequently developed a fatal pseudoaneurysm of the petrous internal carotid *** SUMMARY A 39-year-old man was diagnosed with nasopharyngeal cancer 2 years ago(American Joint Committee on Cancer Stage T3N2M0)and received concurrent chemoradiation *** subsequently relapsed and received *** week after the 4th cycle of chemotherapy,he was admitted to the emergency room of our hospital because of massive epistaxis accompanied by a headache.A pseudoaneurysm of the petrous internal carotid artery was confirmed by digital subtraction angiography(DSA).Stent-assisted endovascular coil embolization was performed and complete occlusion was *** pseudoaneurysm was observed on DSA after coil embolization;however,intermittent epistaxis was maintained even after coil *** seven days,a diagnostic laryngoscopy was *** bleeding occurred after aspiration of the blood clot during the laryngoscopy and the patient died of hypovolemic *** this case,epistaxis may have been a sign of pseudoaneurysm;therefore,treatment such as embolization should be performed promptly,and careful management should be undertaken after *** This case highlights a rare,serious complication of RT in nasopharyngeal cancer and how it should be recognized and treated.

关键词： Pseudoaneurysm Nasopharyngeal cancer Radiation therapy Epistaxis Carotid artery pseudoaneurysm Case report