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Effects of Momentum Ratio and Weber Number on Spray Half Angles of Liquid Controlled Pintle Injector

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Journal of Thermal Science 2015年第1期24卷 37-43页

作者： Min Son Kijeong Yu Jaye Koo Oh Chae Kwon jeong soo kim Korea Aerospace University School of Aerospace and Mechanical Engineering Korea Aerospace University School of Mechanical Engineering Sungkyunkwan University Department of Mechanical Engineering Pukyong National University

A pintle injector is advantageous for throttling a liquid rocket engine and reducing engine weight. This study ex- plores the effects of momentum ratio and Weber number at various injection conditions on spray characteristics of the pintle injector for liquid-gas propellants. A liquid sheet is injected from a center pintle nozzle and it is broken by a gas jet from an annular gap. The pressure drops of propellants, and the pintle opening distance were consi- dered as control variables; using 0.1 -1.0 as a bar for the pressure drop of the liquid injection, a 0.01-4）.2 bar for the pressure drop of gas jet and a 0.2 - 1.0 mm for the pintle opening distance. The discharge coefficient was de- creased linearly before the pintle opening distance of 0.75 mm and then, the coefficient was slightly increased. Spray images were captured by a CMOS camera with high resolution. Then, the shadow and reflected images were analyzed. Spray distributions were measured by a pattemator with an axial distance of 50 mm from a pintle tip. Finally, the spray half angles had an exponentially decreasing correlation as a momentum ratio divided by the Weber number. Also, the spray half angles from the spray distribution were underestimated compared to those measured from the captured images.

关键词： Pintle Injector Spray Half Angle Spray Distribution Visualization

Undiagnosed Borrmann type Ⅱ gastric cancer due to necrosis and regenerative epithelium

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World Journal of Gastroenterology 2014年第28期20卷 9621-9625页

作者： Joon Hur Jae Hyuck Chang Byung Kee kim Hoon Young Ko Jong Hwan Lee soo jeong kim Mi Ae Song Tae Ho kim Chang Whan kim Sok Won Han Division of Gastroenterology Department of Internal MedicineBucheon St.Mary’s HospitalThe Catholic University of KoreaCollege of Medicine Department of Clinical Pathology Bucheon St.Mary’s HospitalThe Catholic University of KoreaCollege of Medicine

Endoscopic biopsy is essential to the proper diagnosis and treatment of gastric ***,the results of endoscopic biopsy are not always the same as what is expected based on gross endoscopic *** results of endoscopic biopsy can be negative for malignancy in Borrmann typeⅣadvanced gastric cancer(AGCa)or gastric ***,in the case of typeⅡAGCa,repeated biopsies negative for malignancy have not been reported.A 49-year-old male patient underwent esophagogastroduodenoscopy three times due to large gastric ulcer suspected to be Borrmann typeⅡ***,three repeat endoscopic biopsies with multiple specimens showed necrosis and superficial regenerative epithelium without malignant *** patient underwent laparoscopic distal gastrectomy with D2 lymph node *** surgical specimen revealed that the mucosal layer was completely replaced with regenerative epithelium without cancer cells.

关键词： Endoscopy Biopsy Stomach neoplasm Stomach ulcer Regeneration

Electrochemical biosensors for point-of-care testing

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Bio-Design and Manufacturing 2024年第4期7卷 548-565页

作者： Jinsol kim Juho jeong Seung Hwan Ko Department of Mechanical Engineering Seoul National UniversitySeoul 08826Republic of Korea Institute of Advanced Machinery and Design(SNU-IAMD) Seoul National UniversitySeoul 08826Republic of Korea

Point-of-care testing(POCT)is the practice of diagnosing and monitoring diseases where the patient is located,as opposed to traditional treatment conducted solely in a medical laboratory or other clinical *** has been less common in the recent past due to a lack of portable medical devices capable of facilitating effective medical ***,recent growth has occurred in this field due to advances in diagnostic technologies,device miniaturization,and progress in wearable *** these developments,electrochemical sensors have attracted interest in the POCT field due to their high sensitivity,compact size,and *** are used in various applications,from disease diagnosis to health status *** this paper we explore recent advancements in electrochemical sensors,the methods of fabricating them,and the various types of sensing mechanisms that can be ***,we delve into methods for immobilizing specific biorecognition elements,including enzymes,antibodies,and aptamers,onto electrode surfaces and how these sensors are used in real-world POCT settings.

关键词： Point-of-care testing(POCT) Electrochemical sensor Enzyme Antibody Health care

Innovative technique of needlescopic grasper-assisted single-incision laparoscopic common bile duct exploration:A comparative study

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World Journal of Gastroenterology 2015年第45期21卷 12857-12864页

作者： Say-June kim Kee-Hwan kim Chang-Hyeok An jeong-soo kim Daejeon St.Mary’s Hospital College of MedicineThe Catholic University of Korea Department of Surgery Uijeongbu St. Mary’s HospitalCollege of MedicineThe Catholic University of Korea

AIM: To investigate the safety and feasibility of needlescopic grasper-assisted single-incision laparoscopic common bile duct exploration(n SIL-CBDE) by comparing the surgical outcomes of this technique with those of conventional laparoscopic CBDE(CL-CBDE).METHODS: We retrospectively analyzed the clinical data of patients who underwent CL-CBDE or n SILCBDE for the treatment of common bile duct(CBD) stones between January 2000 and December 2014. For performing n SIL-CBDE, a needlescopic grasper was also inserted through a direct puncture below the right subcostal line after introducing a single-port through the umbilicus. The needlescopic grasper helped obtain the critical view of safety by retracting the gallbladder laterally and by preventing crossing or conflict between laparoscopic instruments. The gallbladder was then partially dissected from the liver bed and used for retraction. CBD stones were usually extracted through a longitudinal supraduodenal choledochotomy, mostly using flushing a copious amount of normal saline througha ureteral catheter. Afterward, for the certification of CBD clearance, CBDE was performed mostly using a flexible choledochoscope. The choledochotomy site was primarily closed without using a T-tube, and simultaneous cholecystectomies were ***: During the study period, 40 patients underwent laparoscopic CBDE. Of these patients, 20 underwent CL-CBDE and 20 underwent n SIL-CBDE. The operative time for n SIL-CBDE was significantly longer than that for CL-CBDE(238 ± 76 min vs 192 ± 39 min, P = 0.007). The stone clearance rate was 100%(40/40) in both groups. Postoperatively, the n SIL-CBDE group required less intravenous analgesic(pethidine)(46.5 ± 63.5 mg/kg vs 92.5 ± 120.1 mg/kg, P = 0.010) and had a shorter hospital stay than the CL-CBDE group(3.8 ± 2.0 d vs 5.1 ± 1.7 d, P = 0.010). There was no significant difference in the incidence of postoperative complications between the two ***: The results of this study

关键词： Choledocholithiasis Choledochotomy Common bile duc

Enhancement of porcine in vitro embryonic development through luteolin‑mediated activation of the Nrf2/Keap1 signaling pathway

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Journal of Animal Science and Biotechnology 2024年第2期15卷 600-613页

作者： Se-Been Jeon Pil-soo jeong Min Ju kim Hyo-Gu Kang Bong-Seok Song Sun-Uk kim Seong-Keun Cho Bo-Woong Sim Futuristic Animal Resource&Research Center(FARRC) Korea Research Institute of Bioscience and Biotechnology(KRIBB)Cheongju 28116Republic of Korea Department of Animal Science College of Natural Resources&Life SciencePusan National UniversityMiryang 50463Republic of Korea Department of Animal Science and Biotechnology College of Agriculture and Life ScienceChungnam National UniversityDaejeon 34134Republic of Korea Department of Functional Genomics University of Science and TechnologyDaejeon 34113Republic of Korea Department of Animal Science Life and Industry Convergence Research Institute(RICRI)College of Natural Resources&Life SciencePusan National UniversityMiryang 50463Republic of Korea

Background Oxidative stress,caused by an imbalance in the production and elimination of intracellular reactive oxygen species(ROS),has been recognized for its detrimental effects on mammalian embryonic ***(Lut)has been documented for its protective effects against oxidative stress in various ***,its specific role in embryonic development remains *** study aims to investigate the influence of Lut on porcine embryonic development and to elucidate the underlying *** After undergoing parthenogenetic activation(PA)or in vitro fertilization,embryos supplemented with 0.5μmol/L Lut displayed a significant enhancement in cleavage and blastocyst formation rates,with an increase in total cell numbers and a decrease in the apoptosis rate compared to the *** on D2 and D6 revealed that embryos with Lut supplementation had lower ROS levels and higher glutathione levels compared to the ***,Lut supplementation significantly augmented mitochondrial content and membrane ***,activation of the Nrf2/Keap1 signaling pathway was observed in embryos supplemented with Lut,leading to the upregulation of antioxidant-related gene transcription *** further validate the relationship between the Nrf2/Keap1 signaling pathway and effects of Lut in porcine embryonic development,we cultured PA embryos in a medium supplemented with brusatol,with or without the inclusion of *** positive effects of Lut on developmental competence were negated by brusatol *** Our findings indicate that Lut-mediated activation of the Nrf2/Keap1 signaling pathway contributes to the enhanced production of porcine embryos with high developmental competence,and offers insight into the mechanisms regulating early embryonic development.

关键词： Luteolin Mitochondrial function Nrf2/Keap1 signaling pathway Oxidative stress Porcine embryo development

Intelligent structured nanocomposite adhesive for bioelectronics and soft robots

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Nano Research 2024年第2期17卷 534-549页

作者： Yeon soo Lee Min-Seok kim Da Wan kim Changhyun Pang School of Chemical Engineering Sungkyunkwan University(SKKU)Suwon 16419Republic of Korea Mechanical Metrology Group Korea Research Institute of Standards and ScienceDaejeon 34113Republic of Korea Department of Electronic Engineering Korea National University of TransportationChungbuk 27469Republic of Korea Samsung Advanced Institute for Health Sciences and Technology Sungkyunkwan University(SKKU)Suwon 16419Republic of Korea

The remarkable functionality of biological systems in detecting and adapting to various environmental conditions has inspired the design of the latest electronics and robots with advanced *** review focuses on intelligent bio-inspired strategies for developing soft bioelectronics and robotics that can accommodate nanocomposite adhesives and integrate them into biological *** underlying principles of the material and structural design of nanocomposite adhesives were investigated for practical applications with excellent functionalities,such as soft skin-attachable health care sensors,highly stretchable adhesive electrodes,switchable adhesion,and untethered soft *** addition,we have discussed recent progress in the development of effective fabrication methods for micro/nanostructures for integration into devices,presenting the current challenges and prospects.

关键词： biomimetics bio-adhesive switchable adhesion bioelectronics nanocomposite soft robotics

Direct 4D printing of functionally graded hydrogel networks for biodegradable,untethered,and multimorphic soft robots

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International Journal of Extreme Manufacturing 2024年第2期6卷 407-416页

作者： soo Young Cho Dong Hae Ho Sae Byeok Jo jeong Ho Cho Department of Chemical and Biomolecular Engineering Yonsei UniversitySeoul 03722Republic of Korea Department of Mechanical Engineering Virginia TechBlacksburgVA 24061United States of America School of Chemical Engineering Sungkyunkwan UniversitySuwon 16419Republic of Korea SKKU Institute of Energy Science and Technology(SIEST) Sungkyunkwan UniversitySuwon 16419Republic of Korea

Recent advances in functionally graded additive manufacturing(FGAM)technology have enabled the seamless hybridization of multiple functionalities in a single *** robotics can become one of the largest beneficiaries of these advances,through the design of a facile four-dimensional(4D)FGAM process that can grant an intelligent stimuli-responsive mechanical functionality to the printed ***,we present a simple binder jetting approach for the 4D printing of functionally graded porous multi-materials(FGMM)by introducing rationally designed graded multiphase feeder *** graded cross-linking agents gradually form stable porous network structures within aqueous polymer particles,enabling programmable hygroscopic deformation without complex mechanical ***,a systematic bed design incorporating additional functional agents enables a multi-stimuli-responsive and untethered soft robot with stark stimulus *** biodegradability of the proposed 4D-printed soft robot further ensures the sustainability of our approach,with immediate degradation rates of 96.6%within 72 *** proposed 4D printing concept for FGMMs can create new opportunities for intelligent and sustainable additive manufacturing in soft robotics.

关键词： intelligent and sustainable additive manufacturing multi-material four-dimensional printing untethered soft robot multi-stimuli-responsive soft robot biodegradable soft robotics

Integration of earth-abundant cocatalysts for high-performance photoelectrochemical energy conversion

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Journal of Energy Chemistry 2024年第1期88卷 336-355,I0008页

作者： Joonhee Ma Sang Hyun Ahn soo Young kim Department of Materials Science and Engineering Korea UniversitySeoul 02841Republic of Korea School of Chemical Engineering and Materials Science Chung-Ang University84 Heukseok-roDongjak-guSeoul 06974Republic of Korea

Photoelectrochemical(PEC)energy conversion has emerged as a promising and efficient approach to sustainable energy harvesting and *** utilizing semiconductor photoelectrodes,PEC devices can harness solar energy and drive electrochemical reactions such as water splitting or carbon dioxide(CO_(2))reduction to generate clean fuels and value-added ***,PEC energy conversion faces several challenges such as high overpotential,sluggish reaction kinetics,charge carrier recombination,and stability issues,which limit its practical ***,significant research has been conducted to improve the overall conversion efficiency of PEC *** particularly promising approach is the use of cocatalysts,which involves introducing specific cocatalysts onto the photoelectrode surface to promote charge separation,improve reaction kinetics,and reduce the overpotential,thereby enhancing the overall performance of PEC energy *** review provides a comprehensive overview of the recent developments in the earth-abundant cocatalysts for PEC water splitting and CO_(2) *** main earth-abundant catalysts for the PEC water splitting include transition-metal dichalcogenide(TMD)-based materials,metal phosphides/carbides,and metal oxides/***,PEC-CO_(2)RR was divided into C_(1) and C_(2+)based on the final product since various products could be produced,focusing on diverse earth-abundant materials-based *** addition,we provide and highlight key advancements achieved in the very recent reports on novel PEC system design engineering with ***,the current problems associated with PEC systems are discussed along with a suggested direction to overcome these obstacles.

关键词： Solar energy Photo-electrochemical Water splitting CO_(2)reduction Cocatalysts

The SARS-CoV-2 spike protein induces lung cancer migration and invasion in a TLR2-dependent manner

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Cancer Communications 2024年第2期44卷 273-277页

作者： Mi-jeong kim Ji Young kim Ji Hye Shin Juhee Son Yeeun Kang soo-Kyung jeong Duk-Hwan kim Kyun-Hwan kim Eunyoung Chun Ki-Young Lee Department of Immunology Samsung Biomedical Research InstituteSungkyunkwan University School of MedicineSuwonRepublic of Korea Research and Development Center CHA Vaccine InstituteSeongnam-siRepublic of Korea Department of Molecular Cell Biology Sungkyunkwan University School of MedicineSuwonRepublic of Korea Department of Precision Medicine Sungkyunkwan University School of MedicineSuwonRepublic of Korea Department of Health Sciences and Technology Samsung Advanced Institute for Health Sciences&TechnologySamsung Medical CenterSungkyunkwan UniversitySeoulRepublic of Korea

Dear editor,Severe acute respiratory syndrome coronavirus2(SARS-CoV-2)infection can lead to severe outcomes in patients with cancer[1].It has been reported that patients with lung cancers disproportionately manifest severe COVID-19 with a high rate of hospitalization and death[2].Notably,the SARS-CoV-2 Spike(S)protein can induce hyper-inflammation in both epithelial cells and macrophages through toll-like receptor(TLR)1/TLR2 or TLR2/6-dependent nuclear factor-kappaB(NF-κB)path-way[3].However,molecular and cellular evidence on whether the SARS-CoV-2 virus affects the severity of lung cancer patients through TLR1/2 or TLR2/6 signaling remains unclear.

关键词： lung TLR2 invasion