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Photonics Research 2022年第2期10卷 365-372页

作者： Changmin ahn Yongjin na Minji Hyun Jinho Bae Jungwon Kim School of Mechanical and Aerospace Engineering Korea Advanced Institute of Science and Technology(KAIST)Daejeon 34141Republic of Korea

Precise and stable synchronization between an optical frequency comb(femtosecond mode-locked laser oscillator or microresonator-based comb) and a microwave oscillator is important for various fields including telecommunication, radio astronomy, metrology, and ultrafast X-ray and electron science. Timing detection and synchronization using electro-optic sampling with an interferometer has been actively used for low-noise microwave generation, long-distance timing transfer, comb stabilization, time-of-flight sensing, and laser-microwave synchronization for ultrafast science facilities. Despite its outstanding performance, there has been a discrepancy in synchronization performance of more than 10 dB between the projected shot-noise-limited noise floor and the measured residual noise floor. in this work, we demonstrate the shot-noise-limited performance of an electro-optic timing detector-based comb-microwave synchronization, which enabled an unprecedented residual phase noise floor of -174.5 dBc∕Hz at 8 GHz carrier frequency(i.e., 53 zs∕Hz^(1/2)timing noise floor), integrated rms timing jitter of 88 as(1 Hz to 1 MHz), rms timing drift of 319 as over 12 h, and frequency instability of 3.6 × 10^(-20) over 10,000 s averaging time. We identified that bandpass filtering of the microwave signal and optical pulse repetition-rate multiplication are critical for achieving this performance.

关键词： synchronization interferometer Synchronization

Cryo-EM structure of canna.inoid receptor CB1-β-arrestincomplex

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Protein & Cell 2024年第3期15卷 230-234页

作者： Yuxia Wang Lijie Wu Tian Wang Junlin Liu Fei Li Longquan Jiang Zhongbo Fan Yanan Yu na Chen Qianqian Sun Qiwen Tan Tian Hua Zhi-Jie Liu iHuman institute ShanghaiTech UniversityShanghai 201210China School of Life Science and Technology ShanghaiTech UniversityShanghai 201210China institute of Molecular and Clinical Medicine Kunming Medical UniversityKunming 650500China

Dear Editor,G protein-coupled receptors(GPCRs)play a vital role in regulating almost every aspect of human physiology,making up more than one-third of marketed drug targets(Santos et al.,2017).GPCRs orchestrate their signalling through interactions with three distinct downstream protein families:G proteins,G protein-coupled receptor kinases(GRKs),and arrestins(Santos et al.,2017).While G protein-mediated signalling is initiated upon GPCR stimulation,activated GPCRs return to their basal levels through a GRK-and arrestin-regulated desensitization process(Santos et al.,2017).in addition to modulating receptor desensitization,β-arrestin also regulates downstream events that are distinct from classical G protein signalling(ahn et al.,2020).

关键词： stimulation return

Adult neurogenesis in the primate hippocampus

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Zoological Research 2023年第2期44卷 315-322页

作者： Ye Li na-na Xu Zhao-Zhe Hao Sheng Liu State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CenterSun Yat-sen UniversityGuangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouGuangdong 510060China Guangdong Province Key Laboratory of Brain Function and Disease GuangzhouGuangdong 510080China

Adult hippocampal neurogenesis(ahn) is crucial for learning,memory,and *** of ahn may lead to reduced cognitive abilities and neurodegenerative disorders,such as Alzheimer’s *** studies on rodent ahn have clarified the developmental and maturation processes of adult neural stem/progenitor ***,to what extent these findings apply to primates remains *** advances in next-generation sequencing technologies have enabled in-depth investigation of the transcriptome of ahn-related populations at single-cell ***,we summarize studies of ahn in *** suggest that neurogenesis is largely shared across species,but substantial differences also *** gene expression patterns in primates differ from those of *** with rodents,the primate hippocampus has a higher proportion of immature dentate granule cells and a longer maturation period of newly generated granule *** research on species divergence may deepen our understanding of the mechanisms underlying adult neurogenesis in primates.

关键词： Neural precursor cells immature granule cells Sc-Rna-seq

Unexpected Li displacement and suppressed phase transition enabling highly stabilized oxygen redox in P3-type na layered oxide cathode

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Journal of Energy Chemistry 2023年第10期85卷 144-153,I0006页

作者： Myungeun Choi Hobin ahn Hyunyoung Park Yongseok Lee Jinho ahn Bonyoung Ku Junseong Kim Wonseok Ko Jungmin Kang Jung-Keun Yoo Duho Kim Jongsoon Kim Department of Energy Science Sungkyunkwan UniversitySuwon 16419Republic of Korea SKKU institute of Energy Science and Technology(SiEST) Sungkyunkwan UniversitySuwon 16419Republic of Korea Carbon Composites Department Korea Institute of Materials Science(KIMS)Changwon 51508Republic of Korea Department of Mechanical Engineering(integrated Engineering Program) Kyung Hee University1732Deogyeong-daeroGiheung-guYongin-siGyeonggi-do 17104Republic of Korea Department of KHU-KiST Convergence Science and Technology Kyung Hee University23Kyunghee-daero Dongdaemun-guSeoul 02447Republic of Korea

Oxygen redox is considered a new paradigm for increasing the practical capacity and energy density of the layered oxide cathodes for na.ion batteries. However, severe local structural changes and phase transitions during anionic redox reactions lead to poor electrochemical performance with sluggish ***, we propose a synergy of Li-Cu cations in harnessing the full potential of oxygen redox, through Li displacement and suppressed phase transition in P3-type layered oxide cathode. P3-type na_(0.7)[Li_(0.1)Cu_(0.2)Mn_(0.7)]O_(2) cathode delivers a large specific capacity of ~212 mA h g^(-1)at 15 mA g^(-1). The discharge capacity is maintained up to ~90% of the initial capacity after 100 cycles, with stable occurrence of the oxygen redox in the high-voltage region. Through advanced experimental analyses and first-principles calculations, it is confirmed that a stepwise redox reaction based on Cu and O ions occurs for the charge-compensation mechanism upon charging. Based on a concrete understanding of the reaction mechanism, the Li displacement by the synergy of Li-Cu cations plays a crucial role in suppressing the structural change of the P3-type layered material under the oxygen redox reaction, and it is expected to be an effective strategy for stabilizing the oxygen redox in the layered oxides of na.ion batteries.

关键词： Layered oxide cathode Oxygen redox reaction Structural stability Li displacement No phase transition

Massively parallel electro-optic sampling of space-encoded optical pulses for ultrafast multi-dimensional imaging

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Light(Science & Applications) 2023年第2期12卷 304-313页

作者： Yongjin na Hyunsoo Kwak Changmin ahn Seung Eon Lee Woojin Lee Chu-Shik Kang Jungchul Lee Junho Suh Hongki Yoo Jungwon Kim Korea Advanced institute of Science and Technology(KAiST) Daejeon 34141Korea Korea Research institute of Standards and Science(KRiSS) Daejeon 34113Korea

High-speed and high-resolution imaging of surface profiles is critical for the investigation of various structures and mechanical dyna.ics of micro-and nano-scale *** particular,recent emergence of various nonlinear,transient and complex mechanical dyna.ics,such as anharmonic vibrations in mechanical resonators,has necessitated real-time surface deformation imaging with higher axial and lateral resolutions,speed,and dyna.ic ***,real-time capturing of fast and complex mechanical dyna.ics has been challenging,and direct time-domain imaging of displacements and mechanical motions has been a missing element in studying full-field structural and dyna.ic ***,by exploiting the electro-optic sampling with a frequency comb,we demonstrate a line-scan time-of-flight(TOF)camera that can simultaneously measure the TOF changes of more than 1000 spatial coordinates with hundreds megapixels/s pixel-rate and sub-nanometre axial resolution over several millimetres *** unique combina.ion of performances enables fast and precise imaging of both complex structures and dyna.ics in three-dimensional devices and mechanical resonators.

关键词： deformation dimensional dyna.ics

Changes on optical coherence tomography angiography and fluorescein angiography in eyes with neovascular age-related macular degeneration

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interna.ional Journal of Ophthalmology(English edition) 2022年第11期15卷 1837-1844页

作者： So Min ahn Mihyun Choi Cheolmin Yun Seong-Woo Kim Jaeryung Oh Department of Ophthalmology Korea University College of MedicineSeoul 02841Republic of Korea

AiM:lo evaluate the changes on optical coherence tomography angiography(OCTA) and fluorescein angiography(FA) and their correlation in neovascular agerelated macular degeneration(naMD) before and after intravitreal aflibercept injections(iAis).METHODS:in 43 treatment-na?ve patients with naMD,choroidal neovascularization(CNV) in OCTA were morphologically and quantitatively analyzed before and after iAis to determine whether they are correlated with leakage on FA or *** combining CNV in OCTA and leakage in FA,lesions were characterized as three types:L+C+(with both CNV and leakage),L-C+(with CNV but without leakage),or L+C-lesion(with leakage outside CNV).RESULTS:Before iAi,while 27 eyes had L+C+lesion only,16 eyes had both L+C+and L-C+lesions *** capillaries and anastomosis in CNV were more developed in L+C+lesion,at 86.0% and58.1%,respectively,relative to 9.3% and 9.3% in L-C+lesions(PiAis in 33 eyes,tiny capillaries and anastomosis were decreased in the lesions with cessation of leakage on FA(Pively).in quantitative analysis,neovascularization length and numbers of junctions and endpoints were also significantly ***:Leakage on FA is associated with CNV morphology in OCTA and remained so after ***,by carefully assessing the morphological and quantitative changes of CNV in OCTA before and after treatment,activity of naMD is expected even though CNV on OCTA is not completely matched with fluorescein leakage.

关键词： choroidal neovascularization fluorescein angiography leakage neovascular age-related macular degeneration optical coherence tomography angiography

Perforated duodenal ulcer presenting with massive hematochezia in a 30-month-old child

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World Journal of Gastroenterology 2009年第38期15卷 4853-4855页

作者： na Mi Lee Sin Weon Yun Soo ahn Chae Byoung Hoon Yoo Seong Jae Cha Byung Kook Kwak Department of Pediatrics College of MedicineChung-Ang University Department of General Surgery College of MedicineChung-Ang University Department of Radiology College of MedicineChung-Ang University

Peptic ulcer disease is uncommon in children and rarely suspected as a cause of abdominal complaints in this age group; the diagnosis is therefore made almost exclusively when complications develop. Peptic ulcer disease is usually not considered in the differential diagnosis of pediatric patients. We present the case of a 30-month-old boy with duodenal perforation due to a peptic ulcer without a known etiology. The patient was admitted through the emergency department due to severe hematochezia and ongoing anemia; he presented with neither abdominal pain nor abdominal distension. There were no medical problems, and no drugs, such as corticosteroids or nonsteroidal anti-inflammatory drugs, had been prescribed or administered recently. We tried to control the active bleeding by medical treatment including arterial embolization, but the active bleeding was not controlled. Finally, an exploratory laparotomy was performed. A discrete anterior perforation with active bleeding of the duodenal wall was found. After the operation, there were no complications and the patient recovered fully.

关键词：十二指肠溃疡病穿孔便血孩子鉴别诊断活动性消化性

Reevaluation of the expanded indications in undifferentiated early gastric cancer for endoscopic submucosal dissection

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World Journal of Gastroenterology 2022年第15期28卷 1548-1562页

作者： Jiyoung Yoon Seung-Yeon Yoo Young Soo Park Kee Don Choi Beom Su Kim Moon-Won Yoo in Seob Lee Jeong Hwan Yook Ga Hee Kim Hee Kyong na Ji Yong ahn Jeong Hoon Lee Kee Wook Jung Do Hoon Kim Ho June Song Gin Hyug Lee Hwoon-Yong Jung Department of Gastroenterology Asan Medical CenterUniversity of Ulsan College of MedicineSeoul 05505South Korea Department of Pathology Asan Medical CenterUniversity of Ulsan College of MedicineSeoul 05505South Korea Department of Surgery Asan Medical CenterUniversity of Ulsan College of MedicineSeoul 05505South Korea

BACKGROUND Although the criteria for the indication of endoscopic submucosal dissection(ESD)for undifferentiated early gastric cancer(UD-EGC)have been recently proposed,accumulating reports on the non-negligible rate of lymph node metastasis(LNM)after indicated ESD raise questions on the reliability of the current *** To investigate the prevalence and risk factors of LNM in UD-EGC cases meeting the expanded indication for *** We retrospectively reviewed 4780 UD-EGC cases that underwent surgical resection between January 2008 and February 2019 at Asan Medical Center,a tertiary university hospital in *** identify the risk factors of LNM of UDEGC meeting the expanded criteria for ESD,we performed a case-control study by matching the cases with LNM to those without at a ratio of 1:*** reviewed the clinical,endoscopic,and histologic features of the cases to identify features with a significant difference according to the presence of *** and multivariate logistic regression analyses were performed to estimate the odds ratios(ORs).RESULTS Of the 4780 UD-EGC cases,1240(25.9%)were identified to meet the expanded indication for *** the 1240 cases,14(1.1%)cases had *** the various clinical,endoscopic,and histopathological features that were evaluated,mixed histology(tumors consisting of 10%-90%of signet ring cells)had a marginally significant association(P=0.059)with the risk of ***,diffuse blurring of the muscularis mucosae(MM)underneath the tumorous epithelium,a previously unrecognized histologic feature,had a significant association with the absence of LNM(P=0.028).Multivariate logistic regression analysis showed that the blurring of MM was the only explanatory variable significantly associated with a reduced risk of LNM(OR:0.12,95%Ci:0.02-0.95;P=0.045).CONCLUSiON The risk of LNM is higher than expected when using the current expanded indication for *** evaluation could provide useful clues for reducing the

关键词： Gastric cancer Undifferentiated carcinoma Endoscopic submucosal dissection Lymph node metastasis

Occurrence of anionic redox with absence of full oxidation to Ru^(5+) in high-energy P2-type layered oxide cathode

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Journal of Energy Chemistry 2023年第9期84卷 153-161页

作者： Jinho ahn Hyunyoung Park Wonseok Ko Yongseok Lee Jungmin Kang Seokjin Lee Sangyeop Lee Eunji Sim Kyuwook ihm Jihyun Hong Jung-Keun Yoo Kyojin Ku Jongsoon Kim Department of Energy Science Sungkyunkwan UniversitySuwon 16419Republic of Korea SKKU institute of Energy Science and Technology(SiEST) Sungkyunkwan UniversitySuwon 16419Republic of Korea nano&interface Research Team Pohang Accelerator LaboratoryPohang 37673Republic of Korea Department of Smart Fabrication Technology Sungkyunkwan UniversitySuwon 16419Republic of Korea Energy Materials Research Center Korea Institute of Science and Technology(KIST)14 Gil 5 Hwarang-roSeongbuk-guSeoul 02792Republic of Korea Carbon Composites Department Composites Research DivisionKorea Institute of Materials Science(KIMS)797 ChangwondaeroChangwon 51508Republic of Korea Department of Materials Science and Engineering Hanbat National UniversityDaejeon 34158Republic of Korea

The anionic redox has been widely studied in layered-oxide-cathodes in attempts to achieve highenergy-density for na.ion batteries(NiBs).it is known that an oxidation state of Mn^(4+) or Ru^(5+) is essential for the anionic reaction of O^(2-)/O~-to occur during na^(+) de/***,here,we report that the anionic redox can occur in Ru-based layered-oxide-cathodes before full oxidation of Ru^(4+)/Ru^(5+).Combining studies using first-principles calculation and experimental techniques reveals that further na^(+) deintercalation from P2-na_(0.33)[Mg_(0.33)Ru_(0.67)]O_(2) is based on anionic oxidation after 0.33 mol na^(+) deintercalation from P2-na_(0.67)[Mg_(0.33)Ru_(0.67)]O_(2) with cationic oxidation of Ru^(4+)/Ru^(4.5+).Especially,it is revealed that the only oxygen neighboring 2Mg/1 Ru can participate in the anionic redox during na^(+) de/intercalation,which implies that the na-O-Mg arrangement in the P2-na_(0.33)[M9_(0.33)Ru_(0.67)]O_(2) structure can dramatically lower the thermodyna.ic stability of the anionic redox than that of cationic *** the O anionic and Ru cationic reaction,P2-na_(0.67)[Mg_(0.33)Ru_(0.67)]O_(2) exhibits not only a large specific capacity of~172 mA h g^(-1) but also excellent power-capability via facile na^(+) diffusion and reversible structural change during charge/*** findings suggest a novel strategy that can increase the activity of anionic redox by modulating the local environment around oxygen to develop high-energy-density cathode materials for NiBs.

关键词： na.ion batteries P2-type cathode Anionic redox Local environment First-principles calculation

Adsorption characteristics of Cd(Ⅱ) and Ni(Ⅱ) from aqueous solution using succinylated hay

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interna.ional Journal of Minerals,Metallurgy and Materials 2019年第10期26卷 1239-1246页

作者： Peijia Lin Jiajia Wu Junmo ahn Jaeheon Lee Department of Mining and Geological Engineering The University of Arizona

An environmentally friendly organic biosorbent was fabricated using hay by succinylation. Metallic cation adsorption tests were performed using synthetic nickel(Ⅱ) and cadmium(Ⅱ) solutions to simulate heavy-metal recovery from aqueous solution. The adsorption efficiency was greater than 98% for both cadmium and nickel ions when the biosorbent concentration was 5.0 g/L and the initial metal concentrations were 50 mg/L. The surface of the biosorbent was characterized using Fourier transform infrared spectroscopy to investigate the changes in the surface functional groups. The functional groups changed according to the surface treatment, resulting in an effective biosorbent. The kinetics of the metals adsorption revealed that the reactions are pseudo-second order, and the adsorption isotherm well followed the Langmuir model. The maximum adsorption capacities predicted by the Langmuir model were 75.19 mg/g and 57.77 mg/g for cadmium and nickel, respectively. The fabricated biosorbent was regenerated using na Cl multiple times, with 2.1% for Cd and 4.0% for Ni in adsorption capacity after three regeneration cycles. The proposed biosorbent can be a good alterna.ive to resin or other chemical adsorbents for heavy-metal recovery in metallurgical processing or municipal water treatment.

关键词： cadmium nickel biosorbent succinylation hay langmuir adsorption