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Depolarization mitigated in ferroelectric Hf_(0.5)Zr_(0.5)O_(2)ultrathin films(<5 nm)on Si substrate by interface engineering

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Journal of Advanced Ceramics 2024年第3期13卷 282-292页

作者： Se Hyun Kim Younghwan Lee Dong Hyun Lee Geun Hyeong Park Hyun Woo Jeong Kun Yang yong Hyeon cho Young yong Kim Min Hyuk Park Department of Materials Science and Engineering College of EngineeringSeoul National UniversitySeoul 08826Republic of Korea Research Institute of Advanced Materials College of EngineeringSeoul National UniversitySeoul 08826Republic of Korea Inter-university Semiconductor Research Center College of EngineeringSeoul National UniversitySeoul 08826Republic of Korea Pohang Accelerator Laboratory Pohang University of Science&TechnologyPohang 790784Republic of Korea

(Hf,Zr)O_(2)offers considerable potential for next-generation semiconductor devices owing to its nonvolatile spontaneous polarization at the ***,scaling this material to sub-5 nm thickness poses several challenges,including the formation of an interfacial layer and high trap *** particular,a low-k SiO_(2)interfacial layer is naturally formed when(Hf,Zr)O_(2)films are directly grown on a Si substrate,leading to high depolarization fields and rapid reduction of the remanent *** address these issues,we conducted a study to significantly improve ferroelectricity and switching endurance of(Hf,Zr)O_(2)films with sub-5 nm thicknesses by inserting a TiO_(2)interfacial *** deposition of a Ti film prior to Hf_(0.5)Zr_(0.5)O_(2)film deposition resulted in a high-k TiO_(2)interfacial layer and prevented the direct contact of Hf_(0.5)Zr_(0.5)O_(2)with *** findings show that the high-k TiO_(2)interfacial layer can reduce the SiO_(2)/Si interface trap density and the depolarization field,resulting in a switchable polarization of 60.2μC/cm^(2)for a 5 nm thick Hf_(0.5)Zr_(0.5)O_(2)***,we propose that inserting a high-k TiO_(2)interfacial layer between the Hf_(0.5)Zr_(0.5)O_(2)film and the Si substrate may offer a promising solution to enhancing the ferroelectricity and reliability of(Hf,Zr)O_(2)grown on the Si substrate and can pave the way for next-generation semiconductor devices with improved performance.

关键词： ferroelectric charge trapping hafnia depolarization

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Neural Regeneration Research 2011年第4期6卷 283-287页

作者： Sung Ho Jang sang-Hyun cho Mi Young Lee yong Hyun Kwon Min Cheul Chang Department of Physical Medicine and Rehabilitation College of MedicineYeungnam UniversityDaegu 705-717Republic of Korea Department of Physical Therapy Institute of Health ScienceYonsei University College of Health ScienceWounju-siGangwon-do 220-710Republic of Korea Department of Physical Therapy College of Health and TherapyDaegu Haany UniversitySuseongkuDaegu 706-060Republic of Korea Department of Physical Therapy Yeungnam College of Science and TechnologyNamkuDaegu 705-703Republic of Korea

The corticospinal tract （CST） is one of the most important neural tracts for motor function in the human brain. Little is known about age-related changes of the CST. tn this study, we tried to evaluate age-related changes of the CST using diffusion tensor imaging in 60 healthy subjects. The diffusion tensor imaging result revealed that the tract number and fractional anisotropy value were decreased, and the apparent diffusion coefficient （ADC） value was increased with aging. The distribution showed a semilog pattern for tract number, fractional anisotropy and ADC of the CST, and the pattern of each graph was near-linear. When compared with the diffusion tensor imaging parameters of subjects in the 20 s age group, tract number and fractional anisotropy values were significantly decreased in the 50 s-70 s age groups. Likewise, the ADC value was significantly higher in the 50 s-70 s age groups. The CST in the brain of normal subjects degenerated continuously from the 20 s to the 70 s, with a near-linear pattern, and degeneration of the CST began to manifest significantly in the subjects in their 50 s, compared with the subjects in their 20 s.

关键词： corticospinal tract motor function aging diffusion tensor imaging

Sol-gel synthesis and characterization of hydroxyapatite nanorods

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Particuology 2009年第6期7卷 466-470页

作者： Sanosh Kunjalukkal Padmanabhan Avinash Balakrishnan Min-Cheol Chu yong Jin Lee Taik Nam Kim Seong-Jai cho Department of Information and Electronic Materials Engineering College of EngineeringPaichai UniversityDaejeon 302-735Republic of Korea Division of Metrology for Emerging Technology Korea Research Institute of Standards and Science1 Doryong-DongYuseong-GuDaejeon 305-340Republic of Korea Division of Advanced Technology Korea Research Institute of Standards and ScienceDaejeon 305-340Republic of Korea

In the present study hydroxyapatite （HA） nano-hexagonal rods with 70-90 nm diameter and 400-500 nm length are synthesized using a simple sol-gel route with calcium nitrate and potassium dihydrogenphosphate as calcium and phosphorus precursors respectively. Deionized water was used as a diluting media for HA sol preparation and ammonia was used to adjust the pH = 9. After aging, the HA gel was dried at 60 ℃ and calcined at different temperatures ranging from 300 to 700 ℃. The dried and calcined powders were characterized for phase composition using X-ray diffractrometry, elemental dispersive X-ray and Fourier transform infrared spectroscopy. Rietveld analysis showed the calcined HA powders of high purity with a hexagonal unit cell structure. Calcination yielded HA nanopowders of increased particle size and crystallinity with increase in temperature. The particle size and morphology was studied using transmission electron microscopy. The aspect ratio （length to diameter ratio） of HA nanorods was measured to be between 6 and 7.

关键词： Hydroxyapatite Nanorods Sol-gel Particle size Morphology

Omental infarction diagnosed by computed tomography,missed with ultrasonography:A case report

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World Journal of Clinical Cases 2023年第4期11卷 972-978页

作者： Jae Kyoon Hwang Yu Jeong cho Bo Seung Kang Kyueng-Whan Min Young Seo cho yong Joo Kim Kyung Suk Lee Department of Pediatrics Hanyang University Guri HospitalHanyang University College of MedicineGuri-si 11923Gyeonggi-doSouth Korea Department of Surgery Hanyang University Guri HospitalHanyang University College of MedicineGuri-si 11923Gyeonggi-doSouth Korea Department of Emergency Medicine Hanyang University Guri HospitalHanyang University College of MedicineGuri-si 11923Gyeonggi-doSouth Korea Department of Pathology Hanyang University Guri HospitalHanyang University College of MedicineGuri-si 11923Gyeonggi-doSouth Korea Department of Radiology Hanyang University Guri HospitalHanyang University College of MedicineGuri-si 11923Gyeonggi-doSouth Korea Department of Pediatrics Hanyang University HospitalHanyang University College of MedicineSeoul 04763South Korea

BACKGROUND Omental infarction(OI)is a surgical abdominal disease that is not common in adults and is very rare in *** to various acute abdominal pain diseases including appendicitis,diagnosis was previously achieved by diagnostic laparotomy but more recently,ultrasonography or computed tomography(CT)examination has been *** SUMMARY A 6-year-old healthy boy with no specific medical history visited the emergency room with right lower abdominal *** underwent abdominal ultrasonography by a radiologist to rule out acute *** was discharged with no significant sonographic finding and symptom ***,the symptoms persisted for 2 more days and an outpatient visit was *** outpatient abdominal CT was used to make a diagnosis of *** laparoscopic operation,his symptoms *** In children’s acute abdominal pain,imaging studies should be performed for appendicitis and OI.

关键词： Omental infarction Children Ultrasonography Computed tomography Case report

Suppression of laser-induced choroidal neovascularization by intravitreal injection of tristetraprolin

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International Journal of Ophthalmology(English edition) 2014年第6期7卷 952-958页

作者： yong Wun cho yong Seop Han In Young Chung Seong Jae Kim Seong Wook Seo Ji Myong Yoo Jong Moon Park Department of Ophthalmology Gyeongsang National University School of Medicine Gyeongsang Institute of Health Science Gyeongsang National University

AIM: To examine the effect of intravitreal adenoviral vector-mediated tristetraprolin(Ad-TTP) on VEGF m RNA expression in a rat model of laser-induced choroidal ***: Ad-TTP was prepared using a commercial kit. Retinal laser-induced photocoagulation(10 spots per eye) was performed on rats in this experimental choroidal neovascularization(CNV) model. Rats were divided into four groups: control(single intravitreal injection of balanced salt solution, n =10), laser-induced CNV(photocoagulation only, n =20), laser-induced CNV plus Ad-TTP injection(photocoagulation plus a single intravitreal Ad-TTP injection, n =20) and Ad-TTP injection only(n =10). Changes in choroidal morphology were evaluated in ten rats in the laser only and the laser plus Ad-TTP groups. Two weeks after laser injury, the size of CNV was calculated by perfusion with high-molecular-weight fluorescein isothiocyanate(FITC)-dextran. VEGF m RNA expression in retina-choroid tissue from ten rats in each group was measured by reverse transcription polymerase chain reaction(RT-PCR). RESULTS: Two weeks after treatment, the area of laser-induced CNV was reduced by approximately 60% in the rats given the Ad-TTP injection compared with that in the laser-only group. There was a tendency toward decreased VEGF m RNA expression in the Ad-TTP injection ***: A single intravitreal injection of Ad-TTP significantly suppressed CNV size in this experimental laser-induced CNV model. Ad-TTP injection also decreased VEGF m RNA expression compared with that inthe laser-induced CNV group. The present study is meaningful as the first study to investigate the effect of tristetraprolin delivered via intravitreal injection.

关键词： laser-induced choroidal neovascularization tristetraprolin adenoviral vectors

Flexible highly-effective energy harvester via crystallographic and computational control of nanointerfacial morphotropic piezoelectric thin film

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Nano Research 2017年第2期10卷 437-455页

作者： Chang Kyu Jeong Sung Beom cho Jae Hyun Han Dae yong Park Suyoung Yang Kwi-II Park Jungho Ryu Hoon Sohn yong-Chae Chung Keon Jae Lee Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology (KAIST) 291 Daehak-ro Yuseong-gu Daejeon 34141 Republic of Korea KAISTInstitute for the NanoCentury (KINC) 291 Daehak-ro Yuseong-gu Daejeon 34141 Republic of Korea Division of Materials Science and Engineering Hanyang University 222 Wangsimni-ro Seongdong-gu Seou104763 Republic of Korea Department of Civil and Environmental Engineering KAIST 291 Daehak-ro Yuseong-gu Daejeon 34141 Republic of Korea Department of Energy Engineering Gyeongnam National University of Science and Technology 33 Dongjin-ro Jinju Gyeongnam 52725 Republic of Korea Functional Ceramic Group Korea Institute of Materials Science (KIMS) 797 Changwon-daero Seongsan-gu Changwon Gyeongnam.51508 Republic of Korea

Controlling the properties of piezoelectric thin films is a key aspect for designing highly efficient flexible electromechanical devices. In this stud）~ the crystallographic phenomena of PbZr1-xTixO3 （PZT） thin films caused by distinguished interfacial effects are deeply investigated by overlooking views, including not only an experimental demonstration but also ab initio modeling. The polymorphic phase balance and crystallinity, as well as the crystal orientation of PZT thin films at the morphotropic phase boundary （MPB）, can be stably modulated using interfacial crystal structures. Here, interactions with MgO stabilize the PZT crystallographic system well and induce the texturing influences, while the PZT film remains quasi-stable on a conventional A1203 wafer. On the basis of this fundamental understanding, a high-output flexible energy harvester is developed using the controlled-PZT system, which shows significantly higher performance than the unmodified PZT generator. The voltage, current, and power densities are improved by 556%, 503%, and 822%, respectively, in comparison with the previous flexional single-crystalline piezoelectric device. Finally, the improved flexible generator is applied to harvest tiny vibrational energy from a real traffic system, and it is used to operate a commercial electronic unit. These results clearly indicate that atomic-scale designs can produce significant impacts on macroscopic applications.

关键词： energy harvesting morphotropic phaseboundary (MPB) piezoelectric first-principles calculation lead zirconium titanate(PZT)

Simultaneous determination of fourteen components of Gumiganghwal-tang tablet in human plasma by UPLC-ESI-MS/MS and its application to pharmacokinetic study

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Journal of Pharmaceutical Analysis 2021年第4期11卷 444-457页

作者： Seung-Hyun Jeong Ji-Hun Jang Guk-Yeo Lee Seung-Jung Yang Hea-Young cho yong-Bok Lee College of Pharmacy Chonnam National University77 Yongbong-roBuk-guGwangju61186Republic of Korea National Development Institute of Korean Medicine 288 Udeuraendeu-gilAnyang-myeonJangheung-gunJeollanam-do59338Republic of Korea Department of Oriental Rehabilitation Medicine Dongshin University Gwangju Korean Medicine Hospital141 Wolsan-roNam-guGwangju61619Republic of Korea College of Pharmacy CHA University335 Pangyo-roBundang-guSeongnam-siGyeonggi-do13488Republic of Korea

Gumiganghwal-tang is a traditional herbal medicine widely used for its anti-inflammatory,analgesic,and antipyretic ***,the safety and efficacy of its active ingredients based on an in vivo pharmacokinetic(PK)study have yet been *** have established a sensitive and accurate UPLC-ESI-MS/MS method and conducted a PK study on 14 constituents of Gumiganghwal-tang through human plasma *** conditions were optimized according to the physicochemical properties of the 14 compounds to facilitate efficient separation and eliminate overlap or interference between ***-C18 and Inertsil-C8 columns were used as UPLC stationary phases,and acetonitrile and aqueous formic acid were used as mobile *** the analytes were quantified with a triple quadrupole mass spectrometer using electrospray ionization in multiple reaction monitoring *** chromatograms of 14 bioactive compounds showed excellent elution and sensitivity,and each peak was selectively separated and quantified without interference with each other or *** established analytical method was based on international guidelines and was successfully used to perform PK studies of 14 herbal ingredients in humans after oral administration with Gumiganghwal-tang *** oral absorption of most active components of Gumiganghwal-tang was relatively rapid and remained considerably long in the body to be quantified in plasma up to 48 h after administration.

关键词： Gumiganghwal-tang Fourteen bioactive ingredients Simultaneous analysis UPLC-ESI-MS/MS Pharmacokinetics Clinical study

High-throughput discovery of plastid genes causing albino phenotypes in ornamental chimeric plants

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Horticulture Research 2023年第1期10卷 249-259页

作者： Hyun-Seung Park Jae-Hyeon Jeon Woohyeon cho Yeonjeong Lee Jee Young Park Jiseok Kim Young sang Park Hyun Jo Koo Jung Hwa Kang Taek Joo Lee sang Hoon Kim Jin-Baek Kim Hae-Yun Kwon Suk-Hwan Kim Nam-chon Paek Geupil Jang Jeong-yong Suh Tae-Jin Yang Department of Agriculture Forestry and BioresourcesResearch Institute of Agriculture and Life Sciencesand Plant Genomics and Breeding InstituteCollege of Agriculture and Life SciencesSeoul National UniversitySeoul08826Republic of Korea Department of Integrative Biological Sciences and Industry Sejong UniversitySeoul 05006Korea Hantaek Botanical Garden YonginGyeonggi-do17183Republic of Korea Radiation Breeding Research Team Advanced Radiation Technology InstituteKorea Atomic Energy Research InstituteJeongeup 56212Korea Special Forest Resources Division National Institute of Forest ScienceSuwon 16631Korea School of Biological Sciences and Technology Chonnam National UniversityGwangjuSouth Korea Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences Seoul National UniversitySeoul 08826Korea

Chimeric plants composed of green and albino tissues have great ornamental *** unveil the functional genes responsible for albino phenotypes in chimeric plants,we inspected the complete plastid genomes(plastomes)in green and albino leaf tissues from 23 ornamental chimeric plants belonging to 20 species,including monocots,dicots,and *** nine chimeric plants,plastomes were identical between green and albino ***,another 14 chimeric plants were heteroplasmic,showing a mutation between green and albino *** identified 14 different point mutations in eight functional plastid genes related to plastid-encoded RNA polymerase(rpo)or photosystems which caused albinism in the chimeric *** them,12 were deleterious mutations in the target genes,in which early termination appeared due to small deletion-mediated frameshift or single nucleotide *** was single nucleotide substitution in an intron of the ycf3 and the other was a missense mutation in coding region of the rpoC2 *** inspected chlorophyll structure,protein functional model of the rpoC2,and expression levels of the related genes in green and albino tissues of Reynoutria japonica.A single amino acid change,histidine-to-proline substitution,in the rpoC2 protein may destabilize the peripheral helix of plastid-encoded RNA polymerase,impairing the biosynthesis of the photosynthesis system in the albino tissue of *** chimera plant.

关键词： plast substitution ornamental

Characterization of MAGEG2 with testis-specific expression in mice

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Asian Journal of Andrology 2017年第6期19卷 659-665页

作者： Juri Jeong Sora Jin Heejin choi Jun Tae Kwon Jihye Kim Jaehwan Kim Zee yong Park Chunghee cho School of Life Sciences Gwangju Institute of Science and Technology Gwangju 61005 South Korea.

Male germ cell development is a well-defined process occurring in numerous seminiferous tubules of the testis. Uncovering testicular novel genes related to intrinsic regulation of spermatogenesis is essential for the understanding of spermatogenesis. In the present study, we investigated mouse Mageg2, which belongs to a group of melanoma-associated antigens （MAGEs）. Mageg2 is transcribed in the testis specifically, and its expression level is increased at the pachytene spermatocyte stage, indicating that Mageg2 is expressed predominantly in germ cells. We generated an antibody against mouse MAGEG2 for further characterization at the protein level. Immunoblot analysis suggested that MAGEG2 has specific testicular expression and the expression primarily occurred in pachytene spermatocytes. Proteomic analyses demonstrated that mouse MAGEG2 binded to testicular germ cell-specific serine/threonine-protein kinase 31 （STK31） and heat shock protein 9 （HSPA9）. Direct binding with both interaction partners was confirmed by co-immunoprecipitation. We found that STK31 and HSPA9 bind MAGEG2 directly but not with each other. Interestingly, MAGEG2 reduced the kinase activity of STK31. Our study suggests that mouse MAGEG2 has at least two functions, including chaperone activity related to HSPA9 and regulation of pachytene spermatocyte-specific kinase, STK31. Altogether, our results provide the first information about MAGEG2 at the transcript and protein levels and suggest its potential molecular functions.

关键词： heat shock proteins serine/threonine kinase spermatogenesis testis