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Microsystems & Nanoengineering 2022年第4期8卷 233-249页

作者： Yongkui Tang eun Sok kim Department of Electrical and Computer Engineering University of Southern CaliforniaLos AngelesCA90089-0271USA

Focused ultrasound(FUs)is a powerful tool widely used in biomedical therapy and imaging as well as in sensors and *** focusing techniques based on curved surfaces,metamaterial structures,and multielement phased arrays either present diffculties in massively parallel manufacturing with high precision or require complex drive electronics to *** difficulties have been addressed by microfabricated self-focusing acoustic transducers(SFATs)with Parylene air-cavity Fresnel acoustic lenses(ACFALs),which require a time-demanding step in removing the sacrificial *** paper presents three new and improved types of ACFALs based on polydimethylsiloxane(PDMS),an SU-8/PDMS bilayer,and SU-8,which are manufactured through simple sacrificiallayer-free microfabrication processes that are two to four times faster than that for the Parylene ***,by studying the effect of the lens thickness on the acoustic transmittance through the lens,the performance of the transducers has been optimized with improved thickness control techniques developed for PDMS and *** a result,the measured power transfer effciency(PTE)and peak output acoustic pressure are up to 2.0 and 1.8 times higher than those of the Parylene ACFALs,*** simple microfabrication techniques described in this paper are useful for manufacturing not only high-performance ACFALs but also other miniaturized devices with hollow or suspended structures formicrofluidicand optical applications.

关键词： Parylene Fresnel cavity

Lattice design for a hybrid multi-bend achromat light source

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Nuclear Science and Techniques 2020年第7期31卷 55-64页

作者： eun-San kim Department of Accelerator Science Korea University Sejong CampusSejong 30019Korea

We present a lattice design and beam dynamics analysis for a 4 GeV low-emittance,high-brilliance synchrotron light *** lattice consisted of 26 six-bend achromats with 26 long and 26 short straight *** present the design results for a hybrid multi-bend achromat(HMBA)lattice with a natural emittance of 168 pm and circumference of 729.3 *** cell had 4 longitudinal gradient bendings,2 combined bendings,14 quadrupoles,and 2 families of *** lattice was designed to beflexible to provide both nonzero and zero dispersion functions in the long straight *** two straight sections in each cell had lengths of 5.6 and 1.2 *** ensure sufficient injection,we optimized the design lattice and dynamic *** investigated the dynamic aperture in the lattice with machine errors,and the results showed that the lattice design provides sufficient dynamic aperture after COD correction for beam *** present the results of an injection scheme that demonstrates the space in the injection section and the particle motions of the injected *** also present the results of beam tracking after the beam injection to examine the characteristics of the beam *** designed HMBA lattice was well optimized in terms of the beam parameters and brilliance as an intermediate light source at 4 GeV and a circumference of 729.3 m.

关键词： injection beam lattice

无碱CO_(2)加氢高效制甲酸Pd/g-C_(3)N_(4)催化剂的单原子和纳米簇的协同作用

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Chinese Journal of Catalysis 2023年第4期47卷 214-221页

作者： eun Hyup kim Min Hee Lee Jeehye kim eun Cheol Ra Ju Hyeong Lee Jae Sung Lee 蔚山国家科学技术研究所能源与化学工程学院(UNIST) 韩国

气候变化威胁人类的生存.化石燃料的过度使用导致CO_(2)持续排放是引起全球变暖和气候变化的主要因素,须尽快减少CO_(2)排放.捕获CO_(2)并将其转化为高附加值的燃料和化学品从而循环利用是减少CO_(2)净排放的有效措施.其中,CO_(2)催化... 详细信息

气候变化威胁人类的生存.化石燃料的过度使用导致CO_(2)持续排放是引起全球变暖和气候变化的主要因素,须尽快减少CO_(2)排放.捕获CO_(2)并将其转化为高附加值的燃料和化学品从而循环利用是减少CO_(2)净排放的有效措施.其中,CO_(2)催化加氢制甲酸(HCOOH)是碳捕获与利用(CCU)的有效途径之一,其产物HCOOH可用于防腐剂、牲畜饲料抗菌剂和食品添加剂,也可作为氢载体和直接甲酸燃料电池的燃料.目前,工业上生产HCOOH的工艺包括两个步骤:甲醇和CO在强碱条件下反应生成甲酸甲酯(HCO_(2)CH_(3)),随后水解为HCOOH.该工艺利用来自化石燃料的两种原料,排放出大量CO_(2),同时在水解步骤中使用了过量的酸性水,因此对生态环境产生一定的危害.近年来,以CO_(2)为可再生原料合成HCOOH被广泛研究,人们探索了电化学、光化学、生物和热化学反应等多种途径将CO_(2)还原为HCOOH,以期实现CO_(2)循环利用.上述方法距实际应用尚有一定距离,其中,CO_(2)催化加氢制HCOOH过程最先进,它与当前许多化学工业过程相似.由于CO_(2)分子的化学稳定性,CO_(2)加氢生成HCOOH在热力学上不利,可通过有机碱和无机碱形成甲酸-碱配合物,推动反应向生成HCOOH方向移动.然而,从甲酸基配合物中提取HCOOH需要额外的分离步骤,因此在无碱条件下直接将CO_(2)加氢生成HCOOH非常重要.本课题组致力于研究无碱条件下g-C_(3)N_(4)负载的Pd(记为Pd/CN)催化剂催化CO_(2)加氢合成HCOOH,前期研究(***.,2016,52,14302-14305和***.,2021,396,395-401)发现,通过控制Pd负载量可改变催化剂中Pd单原子/Pd纳米团簇的比例,且当两种状态Pd达到最佳比例时,催化剂催化活性最高.这表明在无碱CO_(2)加氢过程中,Pd单原子与纳米团簇间存在协同作用.此外,最近有关于单原子和纳米团簇在负载金属催化剂中不同作用的报道,如NixMg1-xO催化逆水气变换反应,Ir1/In_(2)O_(3)和Pd/Fe_(3)O_(4)催化CO_(2)加氢制乙醇反应等,这些工作得出相似的结论:单原子金属对CO_(2)活化有效,而纳米团簇对H_(2)活化有效.这对于设计以CO_(2)和H_(2)为反应物的金属催化剂很重要.本工作旨在考察类似的机理是否适用于Pd/CN催化剂在无碱条件下催化CO_(2)加氢制HCOOH过程.通过控制Pd负载量,合成了含有不同比例Pd单原子和Pd纳米团簇的Pd/CN催化剂,Pd与g-C_(3)N_(4)表面碱性位间的强静电相互作用使合成含有大量Pd单原子的Pd/CN催化剂成为可能.在Pd/CN催化剂催化无碱CO_(2)加氢制HCOOH过程中,当两种状态Pd达到最佳比例时,Pd单原子和Pd纳米簇之间存在协同作用,此时催化剂活性最高.实验表明,Pd纳米簇主要通过解离吸附参与H_(2)活化,Pd单原子对CO_(2)活化更有效.在最佳单原子比(单原子数/(单原子数+纳米簇)为41%)时,该催化剂表现出最高的活性,优于文献报道的相似反应条件下Pd催化剂活性.这些发现将为以CO_(2)和H_(2)分子为反应物的反应的催化剂设计提供一定的参考.

关键词：无碱CO_(2)加氢制甲酸 Pd/g-C_(3)N_(4) 单原子催化剂纳米簇催化剂协同效应

A novel method to collect sperm from brood parasitic cuckoos:Urodeum stimulation(UroS)method

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Avian Research 2023年第2期14卷 298-303页

作者： Heesoo Lee hae-Ni kim Jun-Seo Go Myeong-Chan Cha Seongho Yun Sue-Jeong Jin Jin-Won Lee Jeong-Chil Yoo Korea Institute of Ornithology Kyung Hee UniversitySeoul02447Republic of Korea Department of Biology Kyung Hee UniversitySeoul02447Republic of Korea

Sperm competition has been studied in numerous species as a representative example of postcopulatory sexual selection,where sampling sperm from male is the most basic and important *** collection can be tricky in birds,however,because unlike mammals,the genitals of birds are generally latent in the cloacal region and their characteristics vary among *** methods to collect sperm from different birds have been tested,such as cloacal massage,feces collection,and electro-stimulation,but their applicability varies depending on *** this study,we introduced the urodeum stimulation method(UroS method)to collect sperm from Cuculus cuckoos,such as the Common Cuckoo(***).These species are expected to have interesting patterns of pair bonding and sperm competition because of their unique breeding strategy called brood parasitism;however,it remains *** this study,we described the application of our new method to expel semen from male common cuckoos,measured the volume of semen collected,checked the presence of sperm in the semen sample,and finally estimated its success rate among 82 *** were successfully collected from 76 cuckoos(approximately 93%)and the colors and volumes of the samples were very *** was present in 43 of these samples(57%),showing a sperm observation rate approximately twice as high as that of the conventional cloacal massage *** believe that this novel method will contribute to a better understanding of postcopulatory sexual selection in avian brood parasites and facilitate the process of sperm collection and artificial insemination in other medium-sized birds.

关键词： Brood parasitism Cuculus cuckoos Semen collection Sexual selection Sperm competition

On-screen fingerprint sensor with optically and electrically tailored transparent electrode patterns for use on high-resolution mobile displays

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Microsystems & Nanoengineering 2020年第1期6卷 243-254页

作者： Hyun-Joon kim-Lee Seog Woo Hong Dong Kyun kim Jinmyoung kim Hong Suk kim Seok-Whan Chung eun-Hyoung Cho hae-Sung kim Byung-Kyu Lee Device Research Center Samsung Advanced Institute of Technology130 Samsung-roYeongtong-guSuwon-siGyeonggi-do 443-803Republic of Korea

In this study,a mutual capacitive-type on-screen fingerprint sensor,which can recognize fingerprints on a display screen to provide smartphones with full-screen displays with a minimal bezel area,is ***-screen fingerprint sensors are fabricated using an indium tin oxide transparent conductor with a sheet resistance of~10Ω/*** a transmittance of~94%(~86% with the substrate effect)in the visible wavelength range,and assembled onto a display *** at this high transmittance,the electrodes can degrade the display quality when they are placed on the *** interference between periodic display pixel arrays and sensor patterns can lead to the *** is necessary to find an appropriate sensor pattern that minimizes the Moirepattern,while maintaining the signal *** search for appropriate patterns,a numerical calculation is carried out over wide ranges of pitches and rotation *** range is narrowed for an experimental evaluation,which is used to finally determine the sensor *** the selected sensor pitches are too small to detect capacitance variations,three unit patterns are electrically connected to obtain a unit block generating a larger *** applying the selected sensor pattern and circuit driving by block,fingerprint sensing on a display is demonstrated with a prototype built on a commercial smartphone.

关键词： transparent pattern smart

Computational approaches for fast generation of digital 3D video holograms(Invited Paper)

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Chinese Optics Letters 2009年第12期7卷 1083-1091页

作者： Seung-Cheol kim eun-Soo kim 3D Display Research Center Department of Electronic Engineering Kwangwoon University

Several approaches for fast generation of digital holograms of a three-dimensional （3D） object have been discussed. Among them, the novel look-up table （N-LUT） method is analyzed to dramatically reduce the number of pre-calculated fringe patterns required for computation of digital holograms of a 3D object by employing a new concept of principal fringe patterns, so that problems of computational complexity and huge memory size of the conventional ray-tracing and look-up table methods have been considerably alleviated. Meanwhile, as the 3D video images have a lot of temporally or spatially redundant data in their inter- and intra-frames, computation time of the 3D video holograms could be also reduced just by removing these redundant data. Thus, a couple of computational methods for generation of 3D video holograms by combined use of the N-LUT method and data compression algorithms are also presented and discussed. Some experimental results finally reveal that by using this approach a great reduction of computation time of 3D video holograms could be achieved.

关键词： LUT Computational approaches for fast generation of digital 3D video holograms CGH

Corrosion characteristics of single-phase Mg-3Zn alloy thin film for biodegradable electronics

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Journal of Magnesium and Alloys 2023年第9期11卷 3241-3254页

作者： Ji-Woo Gu Jae-Young Bae Guangzhe Li hae Won Hwang So-Hyeon Lee Sung-Geun Choi Ju-Young kim Myoung-Ryul Ok Yu-Chan kim Seung-Kyun Kang Department of Materials Science and Engineering Seoul National University(SNU)Seoul 08826Republic of Korea Research Institute of Advanced Materials(RIAM) Seoul National UniversitySeoul 08826Republic of Korea Soft Foundry Nano Systems Institute(NSI) Seoul National UniversitySeoul 08826Republic of Korea Biomaterials Research Center Biomedical Research DivisionKorea Institute of Science and Technology(KIST)Seoul 34141Republic of Korea Division of Bio-Medical Science and Technology KIST SchoolKorea University of Science and TechnologySeoul 02792Republic of Korea Department of Materials Science and Engineering Ulsan National Institute of Science and Technology(UNIST)Ulsan 44919Republic of Korea

Biodegradable metals as electrodes, interconnectors, and device conductors are essential components in the emergence of transient electronics, either for passive implants or active electronic devices, especially in the fields of biomedical electronics. Magnesium and its alloys are strong candidates for biodegradable and implantable conducting materials because of their high conductivity and biocompatibility, in addition to their well-understood dissolution behavior. One critical drawback of Mg and its alloys is their considerably high dissolution rates originating from their low anodic potential, which disturbs the compatibility to biomedical applications. Herein, we introduce a single-phase thin film of a Mg-Zn binary alloy formed by sputtering, which enhances the corrosion resistance of the device electrode, and verify its applicability in biodegradable electronics. The formation of a homogeneous solid solution of single-phase Mg-3Zn was confirmed through X-ray diffraction and transmission electron microscopy. In addition, the dissolution behavior and chemistry was also investigated in various biological fluids by considering the effect of different ion species. Micro-tensile tests showed that the Mg-3Zn alloy electrode exhibited an enhanced yield strain and elongation in relation to a pure Mg electrode. Cell viability test revealed the high biocompatibility rate of the Mg-3Zn binary alloy thin film. Finally, the fabrication of a wireless heater demonstrated the integrability of biodegradable electrodes and highlighted the ability to prolong the lifecycle of thermotherapy-relevant electronics by enhancing the dissolution resistance of the Mg alloy.

关键词： Biodegradable alloy Mg-3Zn binary alloy Solid-solution thin film electrode Biodegradable conductor Transient electronics

Bio-printing of aligned GelMa-based cell-laden structure for muscle tissue regeneration

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Bioactive Materials 2022年第2期7卷 57-70页

作者： Hanjun Hwangbo Hyeongjin Lee eun-Ju Jin JaeYoon Lee Yunju Jo Dongryeol Ryu GeunHyung kim Department of Biomechatronics Engineering College of Biotechnology and BioengineeringSungkyunkwan University(SKKU)Suwon16419Republic of Korea Department of Molecular Cell Biology Sungkyunkwan University School of Medicine(SKKU-SOM)Suwon16419Republic of Korea Biomedical Institute for Convergence at SKKU(BICS) Sungkyunkwan UniversitySuwon16419Republic of Korea

Volumetric muscle loss(VML)is associated with a severe loss of muscle tissue that overwhelms the regenerative potential of skeletal *** engineering has shown promise for the treatment of VML injuries,as evidenced by various preclinical *** present study describes the fabrication of a cell-laden GelMa muscle construct using an in situ crosslinking(ISC)strategy to improve muscle *** obtain optimal biophysical properties of the muscle construct,two UV exposure sources,UV exposure dose,and wall shear stress were evaluated using C2C12 ***,the ISC system showed a significantly higher degree of uniaxial alignment and myogenesis compared to the conventional crosslinking strategy(post-crosslinking).To evaluate the in vivo regenerative potential,muscle constructs laden with human adipose stem cells were *** VML defect group implanted with the bio-printed muscle construct showed significant restoration of functionality and muscular *** data presented in this study suggest that stem cell-based therapies combined with the modified bioprinting process could potentially be effective against VML injuries.

关键词： GelMa bio-ink in-situ crosslinking 3D bioprinting Myogenesis

Second-line bismuth-containing quadruple therapy for Helicobacter pylori eradication and impact of diabetes

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World Journal of Gastroenterology 2017年第6期23卷 1059-1066页

作者： Sung eun kim Moo In Park Seun Ja Park Won Moon Jae Hyun kim Kyoungwon Jung hae Koo kim Young Dal Lee Department of Internal Medicine Kosin University College of MedicineBusan 49267South Korea

AIM To investigate Helicobacter pylori (H. pylori) eradication rates using second-line bismuth-containing quadruple therapy and to identify predictors of eradication *** This study included 636 patients who failed firstline triple therapy and received 7d of bismuthcontaining quadruple therapy between January 2005 and December 2015. We retrospectively demonstrated H. pylori eradication rates with respect to the year of therapy as well as demographic and clinical factors. H. pylori eradication was confirmed by a 13C-urea breath test or a rapid urease test at least 4 wk after the completion of bismuth-based quadruple therapy: proton pump inhibitor, metronidazole, bismuth, and *** The overall eradication rates by intention-to-treat analysis and per-protocol analysis were 73.9%( 95% CI : 70.1 %- 77.4%) and 94.5% (95% CI : 92.4%-96.5%), respectively. Annual eradication rates from 2005 to 2015 were 100.0%, 92.9%, 100.0%, 100.0%, 100.0%, 97.4%, 100.0%, 93.8%, 84.4%, 98.9%, and 92.5%, respectively, by per-protocol analysis. A multivariate analysis showed that diabetes mellitus (OR=3.99, 95%CI: 1.56-10.20, P=0.004)was associated with H. pylori eradication therapy *** The second-line bismuth-containing quadruple therapy for H. pylori infection is still effective in Korea, and diabetes mellitus is suggested to be a risk factor for eradication failure.

关键词： Helicobacter pylori 疾病根除治疗失败铋糖尿病 mellitus

Role of multidetector computed tomography in patients with acute infectious colitis

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World Journal of Clinical Cases 2022年第12期10卷 3686-3697页

作者： Seung Jung Yu Jae Hyuk Heo eun Jeong Choi Jong Hyuk kim Hong Sub Lee Sun Young kim Jae Hoon Lim Department of Internal Medicine Inje University Busan Paik HospitalBusan 47392South Korea Department of Radiology Myongji HospitalHanyang University College of MedicineGoyang 10475South Korea Department of Cancer Control and Population Health National Cancer CenterGoyang 10408South Korea

BACKGROUND The role of multidetector computed tomography(MDCT)in patients with acute infectious colitis is still *** To examine the usefulness of MDCT in distinguishing the etiology of acute infectious *** Overall,244 patients who met the criteria for acute infectious colitis and visited the Hospital from February 2015 to 2018 were retrospectively enrolled and divided into two groups(bacterial:204,viral:40)according to causes of acute colitis,based on stool *** MDCT parameters,including wall thickening,submucosal edema,mucosal enhancement,serosa involvement,empty colon sign,small bowel involvement,comb sign,continuous distribution,accordion sign,mucosal thickening,and lymph node enlargement,were constructed in a blinded *** MDCT parameters of wall thickening(OR:13.60;95%CI:5.80–31.88;P<0.001),submucosal edema(OR:36.08;95%CI:13.54–96.13;P<0.001),mucosal enhancement(OR:22.55;95%CI:9.28–54.81;P<0.001),serosal involvement(OR:14.50;95%CI:3.33–63.23;P<0.001),empty colon sign(OR:6.68;95%CI: 2.44–18.32;P < 0.001), continuous distribution (OR: 24.09;95%CI: 9.38–61.90;P < 0.001), accordionsign (OR: 9.02;95%CI: 1.12–72.35;P = 0.038), mucosal thickening (OR: 46.41;95%CI: 10.38–207.51;P< 0.001), and lymph node enlargement (OR: 4.39;95%CI: 1.22–15.72;P = 0.023) were significantlyassociated with bacterial colitis. At least one positive finding in four CT outcomes (submucosaledema, mucosal enhancement, continuous distribution, mucosal thickening) in summer showed ahigh probability of bacterial colitis (sensitivity, 41.67;specificity, 92.50;OR: 24.95).CONCLUSIONMDCT provides many clues that can be useful in suggesting a specific etiology of acute infectiouscolitis.

关键词： Colitis Multidetector computed tomography Differential diagnosis Bacterial infections Viral infections