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Fung E, Chan EYS, Ng KH, Yu KM, Li H, Wang Y. Towards clinical application of GlycA and GlycB for early detection of inflammation associated with (pre)diabetes and cardiovascular disease: recent evidence and updates. J Inflamm (Lond) 2023; 20:32. [PMID: 37814278 PMCID: PMC10563214 DOI: 10.1186/s12950-023-00358-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 09/18/2023] [Indexed: 10/11/2023] Open
Abstract
Cardiometabolic diseases are associated with low-grade inflammation early in life and persists into old age. The long latency period presents opportunities for early detection, lifestyle modification and intervention. However, the performance of conventional biomarker assays to detect low-grade inflammation has been variable, particularly for early-stage cardiometabolic disorder including prediabetes and subclinical atherosclerotic vascular inflammation. During the last decade, the application of nuclear magnetic resonance (NMR) spectroscopy for metabolic profiling of biofluids in translational and epidemiological research has advanced to a stage approaching clinical application. Proton (1H)-NMR profiling induces no destructible physical changes to specimens, and generates quantitative signals from deconvoluted spectra that are highly repeatable and reproducible. Apart from quantitative analysis of amino acids, lipids/lipoproteins, metabolic intermediates and small proteins, 1H-NMR technology is unique in being able to detect composite signals of acute-phase and low-grade inflammation indicated by glycosylated acetyls (GlycA) and N-acetylneuraminic acid (sialic acid) moieties (GlycB). Different from conventional immunoassays that target epitopes and are susceptible to conformational variation in protein structure and binding, GlycA and GlycB signals are stable over time, and maybe complementary as well as superior to high-sensitivity C-reactive protein and other inflammatory cytokines. Here we review the physicochemical principles behind 1H-NMR profiling of GlycA and GlycB, and the available evidence supporting their potential clinical application for the prediction of incident (pre)diabetes, cardiovascular disease, and adverse outcomes.
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Affiliation(s)
- Erik Fung
- Department of Medicine & Therapeutics, Laboratory for Heart Failure + Circulation Research, Li Ka Shing Institute of Health Sciences, and Centre for Cardiovascular Genomics & Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China.
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong Children's Hospital, Kowloon Bay, Kowloon, Hong Kong SAR, China.
- Neural, Vascular, and Metabolic Biology Programme, and Ministry of Education Laboratory for Regenerative Medicine, School of Biomedical Sciences, Faculty of Medicine, Lo Kwee-Seong Integrated Biomedical Sciences Building, Area 39, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China.
- Department of Epidemiology & Biostatistics, School of Public Health, St Mary's Campus, Imperial College London, London, UK.
- School of Medicine, The Chinese University of Hong Kong, Shenzhen, China.
- Prince of Wales Hospital, Room 124010, 10/F, LCWCSB, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong SAR, China.
| | - Eunice Y S Chan
- School of Medicine, The Chinese University of Hong Kong, Shenzhen, China
| | - Kwan Hung Ng
- Department of Medicine & Therapeutics, Laboratory for Heart Failure + Circulation Research, Li Ka Shing Institute of Health Sciences, and Centre for Cardiovascular Genomics & Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong Children's Hospital, Kowloon Bay, Kowloon, Hong Kong SAR, China
| | - Ka Man Yu
- Department of Medicine & Therapeutics, Laboratory for Heart Failure + Circulation Research, Li Ka Shing Institute of Health Sciences, and Centre for Cardiovascular Genomics & Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong Children's Hospital, Kowloon Bay, Kowloon, Hong Kong SAR, China
| | - Huijun Li
- School of Medicine, The Chinese University of Hong Kong, Shenzhen, China
| | - Yulan Wang
- Singapore Phenome Centre, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
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Liu TF, Hu LD, Zhu LW, Yu KM, Liu WD, Shao GC. [A case of acute cervical epidural infection caused by fishbone in pyriform fossa]. Zhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi 2023; 58:271-273. [PMID: 36878510 DOI: 10.3760/cma.j.cn115330-20220608-00338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Affiliation(s)
- T F Liu
- Department of Otorhinolaryngology, Anshan Central Hospital, Anshan 114000, China
| | - L D Hu
- Department of Otorhinolaryngology, Anshan Central Hospital, Anshan 114000, China
| | - L W Zhu
- Department of Image, Anshan Central Hospital, Anshan 114000, China
| | - K M Yu
- Department of Image, Anshan Central Hospital, Anshan 114000, China
| | - W D Liu
- Department of Image, Anshan Central Hospital, Anshan 114000, China
| | - G C Shao
- Department of Neurosurgery, Anshan Central Hospital, Anshan 114000, China
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Li X, Wu G, Zhang L, Huang D, Li Y, Zhang R, Li M, Zhu L, Guo J, Huang T, Shen J, Wei X, Yu KM, Dong J, Altman MS, Ruoff RS, Duan Y, Yu J, Wang Z, Huang X, Ding F, Shi H, Tang W. Single-crystal two-dimensional material epitaxy on tailored non-single-crystal substrates. Nat Commun 2022; 13:1773. [PMID: 35365650 PMCID: PMC8975884 DOI: 10.1038/s41467-022-29451-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 03/15/2022] [Indexed: 01/19/2023] Open
Abstract
The use of single-crystal substrates as templates for the epitaxial growth of single-crystal overlayers has been a primary principle of materials epitaxy for more than 70 years. Here we report our finding that, though counterintuitive, single-crystal 2D materials can be epitaxially grown on twinned crystals. By establishing a geometric principle to describe 2D materials alignment on high-index surfaces, we show that 2D material islands grown on the two sides of a twin boundary can be well aligned. To validate this prediction, wafer-scale Cu foils with abundant twin boundaries were synthesized, and on the surfaces of these polycrystalline Cu foils, we have successfully grown wafer-scale single-crystal graphene and hexagonal boron nitride films. In addition, to greatly increasing the availability of large area high-quality 2D single crystals, our discovery also extends the fundamental understanding of materials epitaxy.
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Affiliation(s)
- Xin Li
- Chongqing Key Laboratory of Multi-Scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, P.R. China.,University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Shijingshan District, Beijing, 100049, P.R. China
| | - Guilin Wu
- International Joint Laboratory for Light Alloys (MOE), College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, P.R. China.,Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing, 100083, P.R. China
| | - Leining Zhang
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea.,Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Deping Huang
- Chongqing Key Laboratory of Multi-Scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, P.R. China
| | - Yunqing Li
- Chongqing Key Laboratory of Multi-Scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, P.R. China.,University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Shijingshan District, Beijing, 100049, P.R. China
| | - Ruiqi Zhang
- Chongqing Key Laboratory of Multi-Scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, P.R. China.,University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Shijingshan District, Beijing, 100049, P.R. China
| | - Meng Li
- Electron Microscope Center, Chongqing University, Chongqing, 400044, PR China
| | - Lin Zhu
- Electron Microscope Center, Chongqing University, Chongqing, 400044, PR China
| | - Jing Guo
- International Joint Laboratory for Light Alloys (MOE), College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, P.R. China
| | - Tianlin Huang
- International Joint Laboratory for Light Alloys (MOE), College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, P.R. China
| | - Jun Shen
- Chongqing Key Laboratory of Multi-Scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, P.R. China
| | - Xingzhan Wei
- Chongqing Key Laboratory of Multi-Scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, P.R. China
| | - Ka Man Yu
- Department of Physics, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong, PR China
| | - Jichen Dong
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea
| | - Michael S Altman
- Department of Physics, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong, PR China
| | - Rodney S Ruoff
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea.,Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.,School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.,School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Yinwu Duan
- Chongqing Key Laboratory of Graphene Film Manufacturing, Chongqing, 401329, P.R. China
| | - Jie Yu
- Chongqing Key Laboratory of Graphene Film Manufacturing, Chongqing, 401329, P.R. China
| | - Zhujun Wang
- Shanghai Tech University, 93 Middle Huaxia Road, Pudong, Shanghai, 201210, P.R. China
| | - Xiaoxu Huang
- International Joint Laboratory for Light Alloys (MOE), College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, P.R. China. .,Shenyang National Laboratory for Materials Science, Chongqing University, Chongqing, 400044, P.R. China.
| | - Feng Ding
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea. .,Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.
| | - Haofei Shi
- Chongqing Key Laboratory of Multi-Scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, P.R. China. .,University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Shijingshan District, Beijing, 100049, P.R. China.
| | - Wenxin Tang
- Electron Microscope Center, Chongqing University, Chongqing, 400044, PR China
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Yu L, Wan W, Yu KM, Altman M, Tang WX. High order phase contrast and source divergence in low energy electron microscopy. Ultramicroscopy 2021; 225:113284. [PMID: 33872959 DOI: 10.1016/j.ultramic.2021.113284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 03/25/2021] [Accepted: 04/10/2021] [Indexed: 11/24/2022]
Abstract
We present experimental observations of high order phase contrast in aberration corrected low energy electron microscopy (AC-LEEM). Phase contrast produced by atomic steps on a Ag (111) surface exhibits prominent high order interference fringes, which have not been reported before. These phase contrast features depend upon defocus and incident electron energy, similar to the prominent first order fringes observed previously and in agreement with Fourier optics (FO) model predictions. The comparison of experimental results and FO model simulations demonstrates that fringe amplitudes are strongly affected at large defocus by the source divergence. This effect is exploited to quantitatively determine the divergence, 0.055 ± 0.005 mrad, of the field emission source in AC-LEEM under the imaging conditions used. Although the divergence determines the spatial coherence of the illumination in microscopy, it has not been possible to characterize this key instrumental parameter in LEEM before.
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Affiliation(s)
- Lei Yu
- College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China.
| | - Weishi Wan
- ShanghaiTech University, Shanghai, 200031, China
| | - Ka Man Yu
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Michael Altman
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
| | - Wen-Xin Tang
- College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China.
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Chegini S, Schilling C, Walgama ES, Yu KM, Thankappan K, Iyer S, Cariati P, Balasubramanian D, Kanatas A, Lai SY, McGurk M. Neck failure following pathologically node-negative neck dissection (pN0) in oral squamous cell carcinoma: a systematic review and meta-analysis. Br J Oral Maxillofac Surg 2021; 59:1157-1165. [PMID: 34281738 DOI: 10.1016/j.bjoms.2021.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 04/01/2021] [Indexed: 11/25/2022]
Abstract
Due to the risk of occult cervical metastasis, elective neck dissection (END) is recommended in the management of patients with early oral cavity squamous cell carcinoma (OSCC) and a clinically node-negative (cN0) neck. This paper presents a systematic review and meta-analysis of studies that recorded isolated regional recurrence (RR) in the pathologically node-negative neck dissection (pN0) neck following END in order to quantify the failure rate. Pubmed and Ovid databases were systematically searched for relevant articles published between January 2009 and January 2019. Studies reporting RR following END in patients with OSCC who had no pathological evidence of lymph node metastasis were eligible for inclusion in this meta-analysis. In addition, a selection of large head and neck units were invited to submit unpublished data. Search criteria produced a list of 5448 papers, of which 18 studies met the inclusion criteria. Three institutions contributed unpublished data. This included a total of 4824 patients with median follow-up of 34 months (2.8 years). Eight datasets included patients staged T1-T4 with RR 17.3% (469/2711), 13 datasets included patients staged T1-T2 with RR 7.5% (158/2113). Overall across all 21 studies, isolated neck recurrence was identified in 627 cases giving a RR of 13.0% (627/4824) on meta-analysis. Understanding the therapeutic effectiveness of END provides context for evaluation of clinical management of the cN0 in these patients. A pathologically negative neck does not guarantee against future recurrence.
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Affiliation(s)
- S Chegini
- Head and Neck Academic Centre, University College London, Gower St, Bloomsbury, London WC1E 6BT, United Kingdom; Department of Oral and Maxillofacial Head and Neck Surgery, University College Hospital London, 235 Euston Rd, Bloomsbury, London NW1 2BU, United Kingdom.
| | - C Schilling
- Head and Neck Academic Centre, University College London, Gower St, Bloomsbury, London WC1E 6BT, United Kingdom; Department of Oral and Maxillofacial Head and Neck Surgery, University College Hospital London, 235 Euston Rd, Bloomsbury, London NW1 2BU, United Kingdom
| | - E S Walgama
- Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - K M Yu
- Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - K Thankappan
- Amrita Institute of Medical Sciences, Amrita Vishwa Vidyapeetham, Kochi, Kerala 682041, India
| | - S Iyer
- Amrita Institute of Medical Sciences, Amrita Vishwa Vidyapeetham, Kochi, Kerala 682041, India
| | - P Cariati
- Department of Oral and Maxillofacial Surgery, Hospital General Universitario de Albacete, Albacete, Spain
| | - D Balasubramanian
- Amrita Institute of Medical Sciences, Amrita Vishwa Vidyapeetham, Kochi, Kerala 682041, India
| | - A Kanatas
- Leeds General Infirmary, Great George St, Leeds LS1 3EX, United Kingdom
| | - S Y Lai
- Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - M McGurk
- Head and Neck Academic Centre, University College London, Gower St, Bloomsbury, London WC1E 6BT, United Kingdom; Department of Oral and Maxillofacial Head and Neck Surgery, University College Hospital London, 235 Euston Rd, Bloomsbury, London NW1 2BU, United Kingdom
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6
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Ramli MNB, Lim YS, Koe CT, Demircioglu D, Tng W, Gonzales KAU, Tan CP, Szczerbinska I, Liang H, Soe EL, Lu Z, Ariyachet C, Yu KM, Koh SH, Yaw LP, Jumat NHB, Lim JSY, Wright G, Shabbir A, Dan YY, Ng HH, Chan YS. Human Pluripotent Stem Cell-Derived Organoids as Models of Liver Disease. Gastroenterology 2020; 159:1471-1486.e12. [PMID: 32553762 DOI: 10.1053/j.gastro.2020.06.010] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 06/02/2020] [Accepted: 06/06/2020] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS There are few in vitro models for studying the 3-dimensional interactions among different liver cell types during organogenesis or disease development. We aimed to generate hepatic organoids that comprise different parenchymal liver cell types and have structural features of the liver, using human pluripotent stem cells. METHODS We cultured H1 human embryonic stem cells (WA-01, passage 27-40) and induced pluripotent stem cells (GM23338) with a series of chemically defined and serum-free media to induce formation of posterior foregut cells, which were differentiated in 3 dimensions into hepatic endoderm spheroids and stepwise into hepatoblast spheroids. Hepatoblast spheroids were reseeded in a high-throughput format and induced to form hepatic organoids; development of functional bile canaliculi was imaged live. Levels of albumin and apolipoprotein B were measured in cell culture supernatants using an enzyme-linked immunosorbent assay. Levels of gamma glutamyl transferase and alkaline phosphatase were measured in cholangiocytes. Organoids were incubated with troglitazone for varying periods and bile transport and accumulation were visualized by live-imaging microscopy. Organoids were incubated with oleic and palmitic acid, and formation of lipid droplets was visualized by staining. We compared gene expression profiles of organoids incubated with free fatty acids or without. We also compared gene expression profiles between liver tissue samples from patients with nonalcoholic steatohepatitis (NASH) versus without. We quantified hepatocyte and cholangiocyte populations in organoids using immunostaining and flow cytometry; cholangiocyte proliferation of cholangiocytes was measured. We compared the bile canaliculi network in the organoids incubated with versus without free fatty acids by live imaging. RESULTS Cells in organoids differentiated into hepatocytes and cholangiocytes, based on the expression of albumin and cytokeratin 7. Hepatocytes were functional, based on secretion of albumin and apolipoprotein B and cytochrome P450 activity; cholangiocytes were functional, based on gamma glutamyl transferase and alkaline phosphatase activity and proliferative responses to secretin. The organoids organized a functional bile canaliculi system, which was disrupted by cholestasis-inducing drugs such as troglitazone. Organoids incubated with free fatty acids had gene expression signatures similar to those of liver tissues from patients with NASH. Incubation of organoids with free fatty acid-enriched media resulted in structural changes associated with nonalcoholic fatty liver disease, such as decay of bile canaliculi network and ductular reactions. CONCLUSIONS We developed a hepatic organoid platform with human cells that can be used to model complex liver diseases, including NASH.
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Affiliation(s)
| | - Yee Siang Lim
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore
| | - Chwee Tat Koe
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore
| | - Deniz Demircioglu
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore
| | - Weiquan Tng
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore
| | - Kevin Andrew Uy Gonzales
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore; Robin Chemers Neustein Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York City, New York
| | - Cheng Peow Tan
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore
| | - Iwona Szczerbinska
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore
| | - Hongqing Liang
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore
| | - Einsi Lynn Soe
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore
| | - Zhiping Lu
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore
| | | | - Ka Man Yu
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore
| | - Shu Hui Koh
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore
| | - Lai Ping Yaw
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore
| | - Nur Halisah Binte Jumat
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - John Soon Yew Lim
- Institute of Medical Biology, A∗STAR, Singapore; Skin Research Institute of Singapore, A∗STAR, Singapore
| | - Graham Wright
- Institute of Medical Biology, A∗STAR, Singapore; Skin Research Institute of Singapore, A∗STAR, Singapore
| | - Asim Shabbir
- Department of Surgery, University Surgical Cluster, National University Hospital, Singapore
| | - Yock Young Dan
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Division of Gastroenterology and Hepatology, University Medicine Cluster, National University Hospital, Singapore
| | - Huck-Hui Ng
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore; Department of Biochemistry, National University of Singapore, Singapore; Department of Biological Sciences, National University of Singapore, Singapore; School of Biological Sciences, Nanyang Technological University, Singapore
| | - Yun-Shen Chan
- Stem Cell and Regenerative Biology, Genome Institute of Singapore, Singapore.
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Luo D, Wang M, Li Y, Kim C, Yu KM, Kim Y, Han H, Biswal M, Huang M, Kwon Y, Goo M, Camacho-Mojica DC, Shi H, Yoo WJ, Altman MS, Shin HJ, Ruoff RS. Adlayer-Free Large-Area Single Crystal Graphene Grown on a Cu(111) Foil. Adv Mater 2019; 31:e1903615. [PMID: 31264306 DOI: 10.1002/adma.201903615] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Indexed: 06/09/2023]
Abstract
To date, thousands of publications have reported chemical vapor deposition growth of "single layer" graphene, but none of them has described truly single layer graphene over large area because a fraction of the area has adlayers. It is found that the amount of subsurface carbon (leading to additional nuclei) in Cu foils directly correlates with the extent of adlayer growth. Annealing in hydrogen gas atmosphere depletes the subsurface carbon in the Cu foil. Adlayer-free single crystal and polycrystalline single layer graphene films are grown on Cu(111) and polycrystalline Cu foils containing no subsurface carbon, respectively. This single crystal graphene contains parallel, centimeter-long ≈100 nm wide "folds," separated by 20 to 50 µm, while folds (and wrinkles) are distributed quasi-randomly in the polycrystalline graphene film. High-performance field-effect transistors are readily fabricated in the large regions between adjacent parallel folds in the adlayer-free single crystal graphene film.
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Affiliation(s)
- Da Luo
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea
| | - Meihui Wang
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Yunqing Li
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Changsik Kim
- SKKU Advanced Institute of Nano-Technology (SAINT), Sungkyunkwan University (SKKU), Gyeonggi-do, 16419, Republic of Korea
| | - Ka Man Yu
- Department of Physics, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Yohan Kim
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Huijun Han
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Mandakini Biswal
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea
| | - Ming Huang
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea
| | - Youngwoo Kwon
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea
| | - Min Goo
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Dulce C Camacho-Mojica
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea
| | - Haofei Shi
- Chongqing Key Laboratory of Multi-scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China
| | - Won Jong Yoo
- SKKU Advanced Institute of Nano-Technology (SAINT), Sungkyunkwan University (SKKU), Gyeonggi-do, 16419, Republic of Korea
| | - Michael S Altman
- Department of Physics, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Hyung-Joon Shin
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Rodney S Ruoff
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
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8
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Abstract
We present the extended Fourier Optics (FO) approach for modeling image formation in aberration-corrected low energy electron microscopy (ac-LEEM). The FO formalism is also generalized for image simulations of one or two-dimensional objects in ac and uncorrected (nac) LEEM. A comparison is made of the extended FO approach presented here and the extended contrast transfer function (CTF) approach for ac-LEEM that was developed earlier. The mathematically rigorous extended FO approach gains an advantage under conditions, particularly defocus, that partial coherence of the illumination may compromise the validity of the approximate CTF intensity calculation. The drawback of the FO approach compared to the CTF approach, which is its slow computational speed, is mitigated partly here by the implementation of a multi-core, multi-threading programming architecture. This work broadens our capabilities to understand the origins of LEEM image contrast and to perform quantitative evaluation of contrast observed in an image focal series.
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Affiliation(s)
- K M Yu
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - K L W Lau
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - M S Altman
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China.
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Lau KLW, Yu KM, Luo D, Ruoff RS, Altman MS. High throughput scanning μLEED imaging of surface structural heterogeneity: Defective graphene on Cu(111). Ultramicroscopy 2019; 200:67-72. [PMID: 30826622 DOI: 10.1016/j.ultramic.2019.02.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Accepted: 02/18/2019] [Indexed: 11/29/2022]
Abstract
Micro-low energy electron diffraction (μLEED) is frequently used in conjunction with low energy electron microscopy (LEEM) to learn about local surface structural features in small selected areas. Scanning μLEED measurements performed with a very small electron beam (250 nm) can provide precise quantitative information about structural variations with high spatial resolution. We have developed the Source Extraction and Photometry (SEP) - Spot Profile Analysis (SPA) tool for evaluating scanning μLEED data with high throughput. The capability to automate diffraction peak identification with SEP-SPA opens up the possibility to investigate systems with complex diffraction patterns in which diffraction peak positions vary rapidly for small lateral displacements on the surface. The application of this tool to evaluate scanning μLEED data obtained for defective graphene on Cu(111) demonstrates its capabilities. A rich rotational domain structure is observed in which a majority of the graphene is co-aligned with the Cu(111) substrate and the significant remainder comprises domains with large rotations and small sizes that are comparable to the small beam size.
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Affiliation(s)
- K L W Lau
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - K M Yu
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - D Luo
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - R S Ruoff
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea; Department of Chemistry, School of Materials Science, School of Chemical Engineering and Energy, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - M S Altman
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China.
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10
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Lii-Rosales A, Han Y, Yu KM, Jing D, Anderson N, Vaknin D, Tringides MC, Evans JW, Altman MS, Thiel PA. Reverse-engineering of graphene on metal surfaces: a case study of embedded ruthenium. Nanotechnology 2018; 29:505601. [PMID: 30222130 DOI: 10.1088/1361-6528/aae1e3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Using scanning tunneling microscopy, x-ray photoelectron spectroscopy, and x-ray absorption spectroscopy, we show that Ru forms metallic nanoislands on graphite, covered by a graphene monolayer. These islands are air-stable, contain 2-4 layers of Ru, and have diameters on the order of 10 nm. To produce these nanoislands two conditions must be met during synthesis. The graphite surface must be ion-bombarded, and subsequently held at an elevated temperature (1000-1180 K) during Ru deposition. A coincidence lattice forms between the graphene overlayer and the Ru island top. Its characteristics-coincidence lattice constant, corrugation amplitude, and variation of carbon lattice appearance within the unit cell-closely resemble the well-established characteristics of single-layer graphene on the (0001) surface of bulk Ru. Quantitative analysis of the graphene lattice in relation to the coincidence lattice on the island tops show that the two-dimensional lattice constant of the underlying metal equals that of bulk Ru(0001), within experimental error. The embedded Ru islands are energetically favored over on-top (adsorbed) islands, based on density-functional-theory calculations for Ru films with 1-3 Ru layers. We propose a formation mechanism in which Ru atoms intercalate via defects that act as entry portals to the carbon galleries, followed by nucleation and growth in the galleries. In this model, high deposition temperature is necessary to prevent blockage of entry portals.
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Affiliation(s)
- Ann Lii-Rosales
- Ames Laboratory, Ames, IA 50011, United States of America. Department of Chemistry, Iowa State University, Ames, IA 50011, United States of America
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11
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Sun Z, To S, Yu KM. One-step generation of hybrid micro-optics with high-frequency diffractive structures on infrared materials by ultra-precision side milling. Opt Express 2018; 26:28161-28177. [PMID: 30469871 DOI: 10.1364/oe.26.028161] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 09/26/2018] [Indexed: 06/09/2023]
Abstract
Hybrid micro-optics of infrared (IR) materials are of great advantage in realizing the function integration and minimization of advanced IR optical systems. However, due to the hard-and-brittle nature of IR materials, it is still challenging for both non-mechanical and mechanical technologies to achieve one-step generation of hybrid infrared micro-optics with high form accuracy. In the present study, a flexible method, namely ultra-precision side milling (UPSM), is first introduced to achieve one-step generation of infrared hybrid micro-optics in ductile mode, and the corresponding reflective diffraction characteristics are analyzed. In UPSM, the reflective/refractive primary surface of the hybrid micro-optics is formed via the removal of workpiece material, and the high-frequent secondary diffractive micro/nanostructures are simultaneously generated by the tool residual marks of cutting trajectories. With the consideration of the changing curvature of the primary surface, the optimal toolpath generation strategy is introduced to acquire the desired shapes of the secondary micro/nanostructures, and the selecting criteria of the machining parameters is discussed to avoid the brittle fractures of IR materials. In practice, two types of hybrid micro-optic components, namely hybrid micro-aspheric arrays and sinusoid grid surface with high-frequent secondary unidirectional phase gratings, are successfully fabricated on single-crystal silicon to validate the proposed method. The method adopted in this study is very promising for the deterministic fabrication of hybrid micro-optics on infrared materials.
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Yuen TS, Ng J, Lam PY, Lau MY, Siu WL, Yu KM, Lo CN. Erratum to “Changes in Lower Limb Strength and Function Following Lumbar Spinal Mobilization” [J Manipulative Physiol Ther. 2017;40(8):587-596]. J Manipulative Physiol Ther 2018; 41:174. [DOI: 10.1016/j.jmpt.2017.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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13
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Yuen TS, Lam PY, Lau MY, Siu WL, Yu KM, Lo CN, Ng J. Changes in Lower Limb Strength and Function Following Lumbar Spinal Mobilization. J Manipulative Physiol Ther 2017; 40:587-596. [PMID: 29187310 DOI: 10.1016/j.jmpt.2017.07.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 06/28/2017] [Accepted: 07/20/2017] [Indexed: 11/19/2022]
Abstract
OBJECTIVE The purpose of this study was to investigate whether grade III passive lumbar rotational mobilization on L2-3 can improve hip flexor strength and performance in the single-leg triple-hop test in asymptomatic young adults. METHODS Twenty-four participants (12 men, 12 women) aged from 19 to 26 years who were positive in the hip flexor "break" test were recruited in this study. They were randomly allocated to the treatment group or sham group. Isometric hip flexor torque (N·m) and single-leg triple-hop distance (cm) were measured before and after a passive lumbar rotational mobilization or a sham intervention. RESULTS After the intervention, both the treatment and sham groups exhibited a significant increase in longest hop distance (P = .040 and .044, respectively). The treatment group had a significantly higher (3.41 ± 5.44%) positive percentage change in torque than the sham group (-2.36 ± 5.81%) (P = .02). CONCLUSION The study results indicated a potential effect of grade III passive lumbar rotational mobilization in improving hip flexor strength. However, whether the improvement in hopping performance was the result of a treatment effect or a learning effect could not be determined.
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Affiliation(s)
- Tsoi Sze Yuen
- Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong
| | - Pui Yu Lam
- Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong
| | - Mei Yan Lau
- Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong
| | - Wai Lam Siu
- Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong
| | - Ka Man Yu
- Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong
| | - Chi Ngai Lo
- Cluster of Health & Social Sciences, Singapore Institute of Technology, Singapore.
| | - Joseph Ng
- Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong
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14
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Yu KM, Locatelli A, Altman MS. Comparing Fourier optics and contrast transfer function modeling of image formation in low energy electron microscopy. Ultramicroscopy 2017; 183:109-116. [PMID: 28366353 DOI: 10.1016/j.ultramic.2017.03.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 03/01/2017] [Accepted: 03/22/2017] [Indexed: 10/19/2022]
Abstract
A theoretical understanding of image formation in cathode lens microscopy can facilitate image interpretation. We compare Fourier Optics (FO) and Contrast Transfer Function (CTF) approaches that were recently adapted from other realms of microscopy to model image formation in low energy electron microscopy (LEEM). Although these two approaches incorporate imaging errors from several sources similarly, they differ in the way that the image intensity is calculated. The simplification that is used in the CTF calculation advantageously leads to its computational efficiency. However, we find that lens aberrations, and spatial and temporal coherence may affect the validity of the CTF approach to model LEEM image formation under certain conditions. In particular, these effects depend strongly on the nature of the object being imaged and also become more pronounced with increasing defocus. While the use of the CTF approach appears to be justified for objects that are routinely imaged with LEEM, comparison of theory to experimental observations of a focal image series for rippled, suspended graphene reveals one example where FO works, but CTF does not. This work alerts us to potential pitfalls and guides the effective use of FO and CTF approaches. It also lays the foundation for quantitative image evaluation using these methods.
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Affiliation(s)
- K M Yu
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - A Locatelli
- Elettra - Sincrotrone Trieste S.C.p.a., S.S. 14 - km 163,5 in AREA Science Park, 34149 Basovizza, Trieste, Italy
| | - M S Altman
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
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15
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Welna M, Baranowski M, Linhart WM, Kudrawiec R, Yu KM, Mayer M, Walukiewicz W. Multicolor emission from intermediate band semiconductor ZnO 1-xSe x. Sci Rep 2017; 7:44214. [PMID: 28287140 PMCID: PMC5347037 DOI: 10.1038/srep44214] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 02/03/2017] [Indexed: 12/04/2022] Open
Abstract
Photoluminescence and photomodulated reflectivity measurements of ZnOSe alloys are used to demonstrate a splitting of the valence band due to the band anticrossing interaction between localized Se states and the extended valence band states of the host ZnO matrix. A strong multiband emission associated with optical transitions from the conduction band to lower E− and upper E+ valence subbands has been observed at room temperature. The composition dependence of the optical transition energies is well explained by the electronic band structure calculated using the kp method combined with the band anticrossing model. The observation of the multiband emission is possible because of relatively long recombination lifetimes. Longer than 1 ns lifetimes for holes photoexcited to the lower valence subband offer a potential of using the alloy as an intermediate band semiconductor for solar power conversion applications.
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Affiliation(s)
- M Welna
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370, Wroclaw, Poland
| | - M Baranowski
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370, Wroclaw, Poland.,Laboratoire National des Champs Magnétiques Intenses, UPR 3228, CNRS-UGA-UPS-INSA, Grenoble and Toulouse, France
| | - W M Linhart
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370, Wroclaw, Poland
| | - R Kudrawiec
- Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370, Wroclaw, Poland
| | - K M Yu
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720, USA.,Department of Physics and Materials Science, City University of Hong Kong, Kowloon, Hong Kong
| | - M Mayer
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720, USA
| | - W Walukiewicz
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720, USA
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16
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Luo J, Li LH, Liu HT, Yu KM, Xu Y, Zuo XJ, Zhu PZ, Ma YF, Fu RKY, Chu PK. Improved ion implant fluence uniformity in hydrogen enhanced glow discharge plasma immersion ion implantation into silicon. Rev Sci Instrum 2014; 85:063506. [PMID: 24985818 DOI: 10.1063/1.4875982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Enhanced glow discharge plasma immersion ion implantation does not require an external plasma source but ion focusing affects the lateral ion fluence uniformity, thereby hampering its use in high-fluence hydrogen ion implantation for thin film transfer and fabrication of silicon-on-insulator. Insertion of a metal ring between the sample stage and glass chamber improves the ion uniformity and reduces the ion fluence non-uniformity as the cathode voltage is raised. Two-dimensional multiple-grid particle-in-cell simulation confirms that the variation of electric field inside the chamber leads to mitigation of the ion focusing phenomenon and the results are corroborated experimentally by hydrogen forward scattering.
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Affiliation(s)
- J Luo
- Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China
| | - L H Li
- Department of 702, Beihang University, Beijing 100191, People's Republic of China
| | - H T Liu
- Department of 702, Beihang University, Beijing 100191, People's Republic of China
| | - K M Yu
- Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - Y Xu
- Department of 702, Beihang University, Beijing 100191, People's Republic of China
| | - X J Zuo
- Department of 702, Beihang University, Beijing 100191, People's Republic of China
| | - P Z Zhu
- Department of 702, Beihang University, Beijing 100191, People's Republic of China
| | - Y F Ma
- Department of 702, Beihang University, Beijing 100191, People's Republic of China
| | - Ricky K Y Fu
- Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China
| | - Paul K Chu
- Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China
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17
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Dobrowolska M, Tivakornsasithorn K, Liu X, Furdyna JK, Berciu M, Yu KM, Walukiewicz W. Controlling the Curie temperature in (Ga,Mn)As through location of the Fermi level within the impurity band. Nat Mater 2012; 11:444-449. [PMID: 22344325 DOI: 10.1038/nmat3250] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 01/18/2012] [Indexed: 05/31/2023]
Abstract
The ferromagnetic semiconductor (Ga,Mn)As has emerged as the most studied material for prototype applications in semiconductor spintronics. Because ferromagnetism in (Ga,Mn)As is hole-mediated, the nature of the hole states has direct and crucial bearing on its Curie temperature T(C). It is vigorously debated, however, whether holes in (Ga,Mn)As reside in the valence band or in an impurity band. Here we combine results of channelling experiments, which measure the concentrations both of Mn ions and of holes relevant to the ferromagnetic order, with magnetization, transport, and magneto-optical data to address this issue. Taken together, these measurements provide strong evidence that it is the location of the Fermi level within the impurity band that determines T(C) through determining the degree of hole localization. This finding differs drastically from the often accepted view that T(C) is controlled by valence band holes, thus opening new avenues for achieving higher values of T(C).
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Affiliation(s)
- M Dobrowolska
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA.
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18
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López N, Reichertz LA, Yu KM, Campman K, Walukiewicz W. Engineering the electronic band structure for multiband solar cells. Phys Rev Lett 2011; 106:028701. [PMID: 21405256 DOI: 10.1103/physrevlett.106.028701] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Revised: 10/26/2010] [Indexed: 05/30/2023]
Abstract
Using the unique features of the electronic band structure of GaN(x)As(1-x) alloys, we have designed, fabricated and tested a multiband photovoltaic device. The device demonstrates an optical activity of three energy bands that absorb, and convert into electrical current, the crucial part of the solar spectrum. The performance of the device and measurements of electroluminescence, quantum efficiency and photomodulated reflectivity are analyzed in terms of the band anticrossing model of the electronic structure of highly mismatched alloys. The results demonstrate the feasibility of using highly mismatched alloys to engineer the semiconductor energy band structure for specific device applications.
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Affiliation(s)
- N López
- Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
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19
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Shin SJ, Guzman J, Yuan CW, Liao CY, Boswell-Koller CN, Stone PR, Dubon OD, Minor AM, Watanabe M, Beeman JW, Yu KM, Ager JW, Chrzan DC, Haller EE. Embedded binary eutectic alloy nanostructures: a new class of phase change materials. Nano Lett 2010; 10:2794-2798. [PMID: 20698591 DOI: 10.1021/nl100670r] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Phase change materials are essential to a number of technologies ranging from optical data storage to energy storage and transport applications. This widespread interest has given rise to a substantial effort to develop bulk phase change materials well suited for desired applications. Here, we suggest a novel and complementary approach, the use of binary eutectic alloy nanoparticles embedded within a matrix. Using GeSn nanoparticles embedded in silica as an example, we establish that the presence of a nanoparticle/matrix interface enables one to stabilize both nanobicrystal and homogeneous alloy morphologies. Further, the kinetics of switching between the two morphologies can be tuned simply by altering the composition.
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Affiliation(s)
- S J Shin
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
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20
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Stone PR, Alberi K, Tardif SKZ, Beeman JW, Yu KM, Walukiewicz W, Dubon OD. Metal-insulator transition by isovalent anion substitution in Ga1-xMnxAs: implications to ferromagnetism. Phys Rev Lett 2008; 101:087203. [PMID: 18764655 DOI: 10.1103/physrevlett.101.087203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2008] [Indexed: 05/26/2023]
Abstract
We have investigated the effect of partial isovalent anion substitution in Ga1-xMnxAs on electrical transport and ferromagnetism. Substitution of only 2.4% of As by P induces a metal-insulator transition at a constant Mn doping of x=0.046 while the replacement of 0.4% As with N results in the crossover from metal to insulator for x=0.037. This remarkable behavior is consistent with a scenario in which holes located within an impurity band are scattered by alloy disorder in the anion sublattice. The shorter mean free path of holes, which mediate ferromagnetism, reduces the Curie temperature T_{C} from 113 to 60 K (100 to 65 K) upon the introduction of 3.1% P (1% N) into the As sublattice.
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Affiliation(s)
- P R Stone
- Department of Materials Science & Engineering, University of California, Berkeley, California 94720, USA.
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21
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Jones RE, Yu KM, Li SX, Walukiewicz W, Ager JW, Haller EE, Lu H, Schaff WJ. Evidence for p-type doping of InN. Phys Rev Lett 2006; 96:125505. [PMID: 16605926 DOI: 10.1103/physrevlett.96.125505] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Indexed: 05/08/2023]
Abstract
The first evidence of successful p-type doping of InN is presented. It is shown that InN:Mg films consist of a p-type bulk region with a thin n-type inversion layer at the surface that prevents electrical contact to the bulk. Capacitance-voltage measurements indicate a net concentration of ionized acceptors below the -type surface. Irradiation with 2 MeV He+ ions is used to convert the bulk of InN:Mg from p to n-type, at which point photoluminescence is recovered. The conversion is well explained by a model assuming two parallel conducting layers (the surface and the bulk) in the films.
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Affiliation(s)
- R E Jones
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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22
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Scarpulla MA, Cardozo BL, Farshchi R, Oo WMH, McCluskey MD, Yu KM, Dubon OD. Ferromagnetism in Ga(1-x)Mn(x)P: evidence for inter-Mn exchange mediated by localized holes within a detached impurity band. Phys Rev Lett 2005; 95:207204. [PMID: 16384094 DOI: 10.1103/physrevlett.95.207204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Revised: 04/20/2005] [Indexed: 05/05/2023]
Abstract
We report an energy gap for hole photoexcitation in ferromagnetic Ga(1-x)Mn(x)P that is tunable by Mn concentration (x < or = 0.06) and by compensation with Te donors. For x approximately 0.06, electrical transport is dominated by excitation across this gap above the Curie temperature (TC) of 60 K and by thermally activated hopping below TC. Magnetization measurements reveal a moment of 3.9 +/- 0.4 muB per substitutional Mn while the large anomalous Hall signal demonstrates that the ferromagnetism is carrier mediated. In aggregate these data indicate that ferromagnetic exchange is mediated by holes localized in a Mn-derived band that is detached from the valence band.
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Affiliation(s)
- M A Scarpulla
- Department of Materials Science & Engineering, University of California, Berkeley, California 94720, USA
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23
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Yu KM, Walukiewicz W, Wu J, Shan W, Beeman JW, Scarpulla MA, Dubon OD, Becla P. Diluted II-VI oxide semiconductors with multiple band gaps. Phys Rev Lett 2003; 91:246403. [PMID: 14683137 DOI: 10.1103/physrevlett.91.246403] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2003] [Indexed: 05/24/2023]
Abstract
We report the realization of a new mult-band-gap semiconductor. Zn(1-y)Mn(y)OxTe1-x alloys have been synthesized using the combination of oxygen ion implantation and pulsed laser melting. Incorporation of small quantities of isovalent oxygen leads to the formation of a narrow, oxygen-derived band of extended states located within the band gap of the Zn(1-y)Mn(y)Te host. When only 1.3% of Te atoms are replaced with oxygen in a Zn0.88Mn0.12Te crystal the resulting band structure consists of two direct band gaps with interband transitions at approximately 1.77 and 2.7 eV. This remarkable modification of the band structure is well described by the band anticrossing model. With multiple band gaps that fall within the solar energy spectrum, Zn(1-y)Mn(y)OxTe1-x is a material perfectly satisfying the conditions for single-junction photovoltaics with the potential for power conversion efficiencies surpassing 50%.
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Affiliation(s)
- K M Yu
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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Yu KM, Walukiewicz W, Wu J, Mars DE, Chamberlin DR, Scarpulla MA, Dubon OD, Geisz JF. Mutual passivation of electrically active and isovalent impurities. Nat Mater 2002; 1:185-189. [PMID: 12618808 DOI: 10.1038/nmat754] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2002] [Accepted: 10/03/2002] [Indexed: 05/24/2023]
Abstract
The alloy GaN(x) As(1-x) (with x typically less than 0.05) is a novel semiconductor that has many interesting electronic properties because of the nitrogen-induced dramatic modifications of the conduction band structure of the host material (GaAs). Here we demonstrate the existence of an entirely new effect in the GaN(x) As(1-x) alloy system in which the Si donor in the substitututional Ga site (Si(Ga)) and the isovalent atom N in the As sublattice (N(As)) passivate each other's electronic activity. This mutual passivation occurs in Si-doped GaN(x) As(1-x) through the formation of nearest-neighbour Si(Ga) -N(As) pairs and is thermally stable up to 950 degrees C. Consequently, Si doping in GaN(x) As(1-x) under equilibrium conditions results in a highly resistive GaN(x) As(1-x) layer with the fundamental bandgap governed by a net 'active' N, roughly equal to the total N content minus the Si concentration. Such mutual passivation is expected to be a general phenomenon for electrically active dopants and localized state impurities that can form nearest-neighbour pairs.
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Affiliation(s)
- K M Yu
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
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Glover CJ, Ridgway MC, Yu KM, Foran GJ, Clerc C, Hansen JL, Nylandsted-Larsen A. Structure and low-temperature thermal relaxation of ion-implanted germanium. J Synchrotron Radiat 2001; 8:773-775. [PMID: 11512927 DOI: 10.1107/s0909049500012620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2000] [Accepted: 09/12/2000] [Indexed: 05/23/2023]
Abstract
The structure of implantation-induced damage in Ge has been investigated using high resolution extended X-ray absorption fine structure spectroscopy (EXAFS). EXAFS data analysis was performed with the Cumulant Method. For the crystalline-to-amorphous transformation, a progressive increase in bond-length was observed without the presence of an asymmetry in interatomic distance distribution (RDF). Beyond the amorphization threshold the RDF was dose dependent and asymmetric, where the bond-length and asymmetry increased as functions of ion dose. Such an effect was attributed to the formation of three- and five-fold coordinated atoms within the amorphous phase. Low-temperature thermal annealing resulted in structural relaxation of the amorphous phase as evidenced by a reduction in the centroid, asymmetry and width of the RDF, as consistent with a reduction in the fraction of non four-fold coordinated atoms. The results have been compared to other EXAFS studies of amorphous Ge, and it is suggested that the range of bond-lengths reported therein is related to the sample preparation method and state of relaxation.
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Affiliation(s)
- C J Glover
- Research School of Physical Sciences and Engineering, Australian National University, Canberra
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Walukiewicz W, Shan W, Yu KM, Ager JW, Haller EE, Miotkowski I, Seong MJ, Alawadhi H, Ramdas AK. Interaction of localized electronic states with the conduction band: band anticrossing in II-VI semiconductor ternaries. Phys Rev Lett 2000; 85:1552-1555. [PMID: 10970552 DOI: 10.1103/physrevlett.85.1552] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2000] [Indexed: 05/23/2023]
Abstract
We report a strongly nonlinear pressure dependence of the band gaps and large downward shifts of the conduction band edges as functions of composition in ZnS xTe (1-x) and ZnSe (y)Te (1-y) alloys. The dependencies are explained by an interaction between localized A1 symmetry states of S or Se atoms and the extended states of the ZnTe matrix. These results, combined with previous studies of III-N-V materials define a new, broad class of semiconductor alloys in which the introduction of highly electronegative atoms leads to dramatic modifications of the conduction band structure. The modifications are well described by the recently introduced band anticrossing model.
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Affiliation(s)
- W Walukiewicz
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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Chen SK, Yu KM, Chen RS, Hsieh CC. Implementation of an oral and maxillofacial radiology image management and communication system. Dentomaxillofac Radiol 1998; 27:358-62. [PMID: 10895635 DOI: 10.1038/sj/dmfr/4600380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
OBJECTIVES To implement an oral and maxillofacial radiology image management and communication system (OMFR IMACS) in the School of Dentistry, National Taiwan University. METHODS An OMFR IMACS has been implemented over 3 years in three phases: (1) Establishment of an OMFR image processing laboratory for research and graduate student training; (2) Installation of network infrastructure and (3) Total system integration. RESULTS AND CONCLUSIONS Intraoral, panoramic, cephalometric, and TMJ radiographs are directly processed with digital image acquisition devices or are converted into a digital format for viewing via UTP cable through FastEthernet in the eleven different divisions of the school. The system archives about 400 Mb of imaging data daily, representing 80% of the workload of the OMFR Division. The system is now used parallel to the conventional film-library system and has been integrated as part of the oral health service.
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Affiliation(s)
- S K Chen
- Department of Dentistry, College of Medicine, National Taiwan University, Taipli
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Abstract
A retrospective study of 316 ovarian neoplasms which had frozen section evaluation between January 1, 1990 to December 31, 1995 was conducted to determine the accuracy of frozen section diagnosis of ovarian neoplasms. The frozen section results were compared with final diagnoses from paraffin sections. The frozen section diagnosis was accurate in 95.2% of all cases and inaccurate in 4.8%. The positive predictive value of a positive (or malignant) frozen section was 100%, the negative predictive value of a negative (or benign) frozen section was 98.2%. The sensitivity for malignant tumors as 87%. For tumors of borderline malignancy, the sensitivity and specificity were 60% and 98.6% respectively. Of the false negative frozen section diagnoses, 73% (8 cases) occurred in tumors of borderline malignancy. We concluded that with the exception of the sensitivity for the diagnosis of tumors of borderline malignancy, the sensitivity and specificity of frozen section diagnosis for benign and overtly malignant ovarian neoplasms are high.
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Affiliation(s)
- E L Yeo
- Department of Obstetrics and Gynaecology, Kwong Wah Hospital, Kowloon, Hong Kong SAR, China
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Chan KS, Yu KM, Lok YH, Sin SY, Tang LC. Conservative management of patients with histological incomplete excision of cervical intraepithelial neoplasia after large loop excision of transformation zone. Chin Med J (Engl) 1997; 110:617-9. [PMID: 9594266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE To evaluate conservative management of patients with histological incomplete excision of CIN after large loop excision of transformation zone (LLETZ). METHODS Two hundred and seventeen patients with high grade CIN were treated with LLETZ from October 1, 1992 to December 31, 1994. Fifty-three patients (24.4%) had incomplete excision on histology. All patients were followed up cytologically every 3 to 6 months during the first 18 months and then yearly till December 1996. Those patients with positive endocervical margins were followed up with both cervical smear and endocervical smear. RESULTS The mean follow-up duration was 30.4 months. Ten patients were found to have persistent or recurrent disease. Five patients had second LLETZ and complete excision was achieved in 4 of them, one patient had cone biopsy and two had hysterectomy. One patient was found to have stage I a cervical cancer. CONCLUSION A report of incomplete excision of CIN after LLETZ calls for follow-up with cytology and colposcopy and not aggressive retreatment.
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Affiliation(s)
- K S Chan
- Department of Obstetrics and Gynaecology, Kwong Wah Hospital, Kowloon, Hong Kong, China
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Yuen PM, Yu KM, Yip SK, Lau WC, Rogers MS, Chang A. A randomized prospective study of laparoscopy and laparotomy in the management of benign ovarian masses. Am J Obstet Gynecol 1997; 177:109-14. [PMID: 9240592 DOI: 10.1016/s0002-9378(97)70447-2] [Citation(s) in RCA: 182] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Our purpose was to compare the results of laparoscopy with laparotomy in the management of ovarian masses not suspected to be malignant. STUDY DESIGN In a prospective randomized study 102 patients requiring surgical management of ovarian masses were randomly assigned to laparoscopy (52) or laparotomy (50) in a teaching hospital from July 1994 to September 1995. Inclusion criteria was tumor not suspected to be malignant with a diameter of < or = 10 cm as measured by ultrasonography. All operations were performed by trainees under the supervision of an experienced surgeon. Statistical analysis included t tests and chi2 tests. RESULTS There were no differences in demographic characteristics between the two groups nor any difference in the size of ovarian masses, adnexal adhesion score, or frequency of bilateral disease. All the ovarian masses were benign. Endometriotic cysts and dermoid cysts were the most common disorder in the two groups. Cystectomy was performed in > 70% of cases in each group. Operating time was not increased with the laparoscopic approach, and the frequency of inadvertent rupture of the ovarian masses was just as high as in laparotomy. The laparoscopic approach was associated with a significant reduction in operative morbidity (odds ratio 0.34, 95% confidence interval 0.13 to 0.88), postoperative pain and analgesic requirement, hospital stay, and recovery period. Patients in general were satisfied with the operation, but significantly more patients were satisfied with the laparoscopy scar. CONCLUSION Operative laparoscopy should replace laparotomy in the management of benign ovarian masses.
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Affiliation(s)
- P M Yuen
- Department of Obstetrics and Gynaecology, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, N.T
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Chan KS, Kwok CW, Yu KM, Sin SY, Tang LCH. A three-year review of treatment of cervical intraepithelial neoplasia with large loop excision of the transformation zone. Hong Kong Med J 1997; 3:21-26. [PMID: 11847352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
One hundred and eighty-five patients were treated with large loop excision of the transformation zone for cervical intraepithelial neoplasia from October 1992 through September 1994. All patients were followed up regularly until September 1995 to review the outcome and morbidity. Cure rates of 97.2% in the first six months and 95.4% at the end of the first 12 months were obtained. Thirteen patients (7.0%) were admitted as emergency cases for post-operative haemorrhage, which required suturing, cauterisation with silver nitrate or electrocoagulation, vaginal douching, or antibiotic treatment. One patient developed cervical stenosis and incomplete excisions were noted in 46 (24.9%) patients. Eleven (6.0%) patients had cervical carcinomas detected. Our findings further confirm that this method is a reliable and safe way to treat cervical intraepithelial neoplasia with an acceptable rate of morbidity.
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Affiliation(s)
- K S Chan
- Department of Obstetrics and Gynaecology, Kwong Wah Hospital, Waterloo Road, Kowloon, Hong Kong
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Abstract
The aim of this observational study is to review the outcome of prophylactic intrapartum amnioinfusion (AI) in pregnancies complicated by moderate to thick meconium-stained liquor (MSL). The labour and neonatal outcome of all 298 AIs performed over a 3-year period were compared to a matched-control group of patients whose labour was complicated by moderate or thick MSL but without AI. The incidence of moderate or thick meconium below the vocal cords of the neonate were significantly lower in the AI group (6.4% and 3.4%) compared with the control group (15.4% and 6.7%). The incidence of meconium aspiration syndrome in the AI group was half (1.7%) that of the control group (3.7%), although the difference did not reach statistical significance. There was a significant higher incidence of cardiotocographic abnormalities in the AI group (30.5% versus 14.7%), with higher incidences of Caesarean section and operative vaginal deliveries. The reduction in the incidence and thickness of meconium after AI was not accompanied by any statistically significant reduction in adverse fetal outcomes such as low Apgar scores, cord pH values, admissions to and duration of admission to the neonatal unit, or the incidence of meconium-aspiration syndrome.
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Affiliation(s)
- M S Rogers
- Department of Obstetrics and Gynaecology, Chinese University of Hong Kong, Shatin, Hong Kong
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Leon RP, Kaminska M, Yu KM, Weber ER. Formation of semi-insulating InP through metallic Cu-rich precipitates. Phys Rev B Condens Matter 1992; 46:12460-12468. [PMID: 10003164 DOI: 10.1103/physrevb.46.12460] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Yu KM. [Relation between placental morphometry and fetal growth]. Zhonghua Fu Chan Ke Za Zhi 1992; 27:217-9, 250. [PMID: 1291218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Forty-eight placentae of full term infants, 21 placentae from appropriate for gestational age infants (AGA) and 27 placentae from small for gestational age infants (SGA) were measured by morphometric technic using the automatic image analyzer, in order to find out the extent of fetomaternal exchange which determines the transfer of oxygen and nutrition from mother to fetus and fetal growth. The results of measurement correlated well both with infant birth weight and placental weight. They demonstrated striking quantitative differences when the placentae of SGA were compared with those of AGA. The placenta weights in the group of SGA were notably less than those in the group of AGA. It seems that low birth weight relates to low functional tissue mass of placenta. This reduction of functional tissue is accompanied by diminution of the area for exchange between mother and fetus, both at the villous surface area and at fetal capillary surface area. Thus, the ability of transferring oxygen and nutrition from mother to fetus is curtailed. The results show that the rate of fetal growth is limited by placental function as well as its weight.
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Affiliation(s)
- K M Yu
- Shanghai Institute for Pediatric Research
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Yu KM, Khachaturyan K, Weber ER, Lee HP, Kolas EG. Substitutionality of Te- and Sn-related DX centers in AlxGa1-xAs. Phys Rev B Condens Matter 1991; 43:2462-2465. [PMID: 9997535 DOI: 10.1103/physrevb.43.2462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Xu L, Ge QS, Zhang YW, Gu CX, Wang HL, Yu KM, Feng DD, Xie YZ. Isosexual precocious puberty. Clinical analysis of 109 patients. Chin Med J (Engl) 1987; 100:865-70. [PMID: 2452720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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Ge QS, Xu L, Wang HL, Gu CX, Zhang YW, Lin SQ, Yu KM, Tang MY, Feng DD. The value of radioimmunoassay of LH, FSH, and PRL in the diagnosis of secondary amenorrhea. Chin Med J (Engl) 1987; 100:477-81. [PMID: 3115727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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Ge QS, Xu L, Wang HL, Gu CX, Lin SQ, Xu YD, Yu KM, Xie YZ, Shi YF, Zang X. Hyperprolactinemia. Its relation to galactorrhea, amenorrhea, pituitary tumor and its management. Chin Med J (Engl) 1985; 98:543-50. [PMID: 3937678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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