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A general phase retrieval algorithm based on a ptychographical iterative engine for coherent diffractive imaging

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Chinese Physics B 2013年第1期22卷 243-248页

作者：傅健李鹏 research center of Digital Radiation Imaging and biomedical Imaging Beijing University of Aeronautics and Astronautics

Coherent diffractive imaging （CDI） is a lensless imaging technique and can achieve a resolution beyond the Rayleigh or Abbe limit. The ptychographical iterative engine （PIE） is a CDI phase retrieval algorithm that uses multiple diffraction patterns obtained through the scan of a localized illumination on the specimen, which has been demonstrated successfully at optical and X-ray wavelengths. In this paper, a general PIE algorithm （gPIE） is presented and demonstrated with an He-Ne laser light diffraction dataset. This algorithm not only permits the removal of the accurate model of the illumination function in PIE, but also provides improved convergence speed and retrieval quality.

关键词： phase retrieval algorithm coherent diffractive imaging ptychography

In Vitro Study on Mg-Sn-Mn Alloy as Biodegradable Metals

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Journal of Materials Science & Technology 2014年第7期30卷 675-685页

作者： Zhen Zhen Tingfei Xi Yufeng Zheng Li Li Lugee Li center for biomedical Materials and Tissue Engineering Academy for Advanced Interdisciplinary StudiesPeking University biomedical Engineering research center Shenzhen InstitutePeking University Department of Materials Science and Engineering College of EngineeringPeking University center for biomedical Materials and Engineering Harbin Engineering University Dongguan EONTEC Company Ltd

The mechanical properties, chemical properties and biocompatibility of Mg-3Sn-0.5Mn alloy were tested. A series of in vitro evaluations such as tensile test, static and dynamic immersion test, hemocompatibility test as well as cytotoxicity test were presented, with commercial magnesium alloy WE43 as the control. Mg-3Sn-0.5Mn alloy possesses suitable strength and superior ductility compared with WE43 and AZ31. Static immersion and dynamic degradation tests showed more uniform degradation with a more moderate rate for Mg-3Sn-0.5Mn alloy （0.34 mm/y in static condition and 0.25 mm/y in dynamic condition） compared with WE43 alloy （0.42 mm/y in static condition and 0.33 mm/y in dynamic condition） in Hank＇s solution. Blood compatibility evaluation suggested that Mg-3Sn-0.5Mn alloy had no destructive effect on erythrocyte and showed excellent anti-thrombogenicity to blood system. Besides, Mg-3Sn-0.5Mn alloy showed no inhibition effect to L929 metabolic activity and mild toxicity to vascular smooth muscle cell （VSMC） in preliminary cell viability assessment. By considering its excellent mechanical strength, corrosion resistance, low ion release rate and good biocompatibility, Mg-3Sn-0.5Mn alloy may be a promising economical candidate as biomedical implant material for load-bearing clinical applications in the future.

关键词： Mg-3Sn-0.5Mn alloy Corrosion Dynamic immersion Static immersion Biodegradable material

Recent advances in parametric neuroreceptor mapping with dynamic PET:basic concepts and graphical analyses

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Neuroscience Bulletin 2014年第5期30卷 733-754页

作者： Seongho Seo Su Jin Kim Dong Soo Lee Jae Sung Lee Department of Nuclear Medicine College of Medicine Department of Brain and Cognitive Sciences College of Natural Sciences institute of Radiation Medicine Medical Research Center Institute of Radiation Medicine Medical Research Center Department of Molecular Medicine and Biopharmaceutical Sciences Graduate School of Convergence Science and Technology Department of biomedical Sciences College of Medicine Seoul National University

Tracer kinetic modeling in dynamic positron emission tomography （PET） has been widely used to investigate the characteristic distribution patterns or dysfunctions of neuroreceptors in brain diseases. Its practical goal has progressed from regional data quantification to parametric mapping that produces images of kinetic-model parameters by fully exploiting the spatiotemporal information in dynamic PET data. Graphical analysis （GA） is a major parametric mapping technique that is independent on any compartmental model configuration, robust to noise, and computationally efficient. In this paper, we provide an overview of recent advances in the parametric mapping of neuroreceptor binding based on GA methods. The associated basic concepts in tracer kinetic modeling are presented, including commonly-used compartment models and major parameters of interest. Technical details of GA approaches for reversible and irreversible radioligands are described, considering both plasma input and reference tissue input models. Their statistical properties are discussed in view of parametric imaging.

关键词： dynamic positron emission tomography graphical analysis neuroreceptor imaging parametric image tracer kinetic modeling

Electric-stimulus rate encoding algorithm of Mandarin tonal information in cochlear implant

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Progress in Natural Science:Materials International 2006年第12期16卷 1315-1321页

作者： GUAN Tian~1, GONG Qin~1 and YE Datian~2**(1. Department of biomedical Engineering, Tsinghua University, Beijing 100084, China 2. research center of biomedical Engineering, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China) Department of biomedical Engineering Tsinghua University Beijing 100084 China research center of biomedical Engineering Graduate School Shenzhen Tsinghua University Shenzhen 518055 China

The modern multi-channel cochlear implants usually extract and encode the temporal envelope cues. This kind of algorithms can hardly satisfy the users who speak tonal languages, such as Mandarin. Many studies have tried to enhance the recognition ability of Mandarin through encoding tonal information and made suggestions to frequency-modulate the fixed pulse-rate carrier with the extracted tonal information based on the rate-pitch theory in electric hearing. However, how to encode and deliver the tonal information such as F_0by changing electric-stimulus rate has not got further study in clinical electric-stimulus mode. The present paper focuses on this matter by piecewise calculating the appreciable electric-stimulus rates. Then an electric-stimulus encoding algorithm of Mandarin tone is brought forward and testified through acoustic simulations. Such conclusion can be drawn that this algorithm of electric-stimulus rate could convey tonal information well and help to enhance the Mandarin speech recognition ability.

关键词： cochlear implant tone fundamental frequency electric-stimulus rate.

Titanium mesh for bone augmentation in oral implantology: current application and progress

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International Journal of Oral Science 2020年第4期12卷 275-286页

作者： Yu Xie Songhang Li Tianxu Zhang Chao Wang Xiaoxiao Cai State Key Laboratory of Oral Diseases&National Clinical research center for Oral Diseases&Dept.of Head and Department of implant Dentistry West China Hospital of StomatologySichuan UniversityChengduChina College of Stomatology Chongqing Medical UniversityChongqingChina Beijing Advanced Innovation center for biomedical Engineering Beihang UniversityBeijingChina

Guided bone regeneration(GBR)is an effective and simple method for bone augmentation,which is often used to reconstruct the alveolar ridge when the bone defect occurs in the implant *** mesh has expanded the indications of GBR technology due to its excellent mechanical properties and biocompatibility,so that the GBR technology can be used to repair alveolar ridges with larger bone defects,and can obtain excellent and stable bone augmentation ***,GBR with titanium mesh has various clinical applications,including different clinical *** graft materials,titanium mesh covering methods,and titanium mesh fixing methods are also ***,the research of GBR with titanium mesh has led to multifarious progresses in digitalization and material *** article reviews the properties of titanium mesh and the difference of titanium mesh with other barrier membranes;the current clinical application of titanium mesh in bone augmentation;common complications and management and prevention methods in the application of titanium mesh;and research progress of titanium mesh in digitization and material *** to provide a reference for further improvement of titanium mesh in clinical application and related research of titanium mesh.

关键词： titanium Titanium mesh

Mucoadhesive and antifouling Janus polysaccharide film for prevention of colorectal cancer recurrence post-surgery

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BMEMat(biomedical Engineering Materials) 2024年第2期2卷 134-144页

作者： Jaebeom Lee Hee Seung Seo Chun Gwon Park Mikyung Shin Department of Intelligent Precision Healthcare convergence Sungkyunkwan University(SKKU)SuwonRepublic of Korea center for Neuroscience Imaging research Institute for Basic Science(IBS)SuwonRepublic of Korea Department of biomedical Engineering Sungkyunkwan University(SKKU)SuwonRepublic of Korea Biomaterials research center Korea Institute of Science and TechnologySeoulRepublic of Korea biomedical Institute for convergence Sungkyunkwan University(SKKU)SuwonRepublic of Korea

Colorectal cancer is one of the most common cancers,and current treatment options include surgery,chemotherapy,and radiation *** patients undergo surgery,which often requires extensive resection of the colon to prevent recurrence and metastasis of residual malignant tumor cells,leading to postoperative pain and discomfort in daily *** versatile therapeutic patches have been developed to induce tumor apoptosis,achieving both great adhesiveness on the mucus layers of the colon tissue and anti-cell/tissue adhesion to other surrounding organs remains a ***,we report a Janus polysaccharide film comprising two polymers:mussel-inspired catechol-conjugated chitosan(Chi-C)with muco-adhesiveness,and alginate(Alg)with anti-adhesion *** Chi-C and Alg polymers form a stably entangled bilayer film via electrostatic *** Janus film shows a strong tissue adhesive strength of~10 kPa for the Chi-C layer and weak strength of~1 kPa for the Alg ***,the Janus film encapsulating an anti-cancer drug exhibits a directional release profile to the tumor site,which is effective for triggering tumor death in in vivo colorectal tumor resection ***,such anti-cancer material strategies using bilayered structures are promising for advanced tumor therapy.

关键词： antifouling colon cancer mucoadhesive polysaccharide film

New magnifying endoscopic classification for superficial esophageal squamous cell carcinoma

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World Journal of Gastroenterology 2017年第24期23卷 4416-4421页

作者： Su Jin Kim Gwang Ha Kim Moon Won Lee Hye Kyung Jeon Dong Hoon Baek Bong Eun Lee Geun Am Song Department of Internal Medicine Pusan National University School of Medicine and Research Institute for Convergence of Biomedical Science and TechnologyPusan National University Yangsan Hospital Department of Internal Medicine Pusan National University School of Medicine and Biomedical Research InstitutePusan National University Hospital

To assess the accuracy of a new magnifying endoscopy (ME) classification for predicting depth of invasion of superficial esophageal squamous cell carcinoma (SESCC). METHODSThis study included a total of 70 lesions in 69 patients with SESCC who underwent ME with narrow-band imaging (ME-NBI) before resection from August 2010 to July 2016. Accuracy of ME-NBI for predicting depth of invasion of SESCC was analyzed by using a new ME classification proposed by the Japan Esophageal Society (JES), and interobserver agreement was assessed. RESULTSOverall accuracy of ME-NBI for estimating depth of invasion of SESCC was 78.6%. Sensitivity and specificity of type B1 for tumors limited to the epithelial layer (m1) or invading into the lamina propria (m2) were 71.4% and 100%, respectively. Sensitivity and specificity of type B2 for tumors invading into the muscularis mucosa (m3) or superficial submucosa (≤ 200 μm, sm1) were 94.4% and 73.1%, respectively, while those of type B3 for tumors invading into the deep submucosa (> 200 μm, sm2) were 75.0% and 97.8%, respectively. Interobserver agreement was excellent (κ = 0.86, 95%CI: 0.76-0.95). CONCLUSIONThe recently developed JES ME classification is useful for predicting depth of invasion of SESCC, with reliable interobserver agreement.

关键词： Narrow-band imaging Esophageal cancer Squamous cell carcinoma Magnifying endoscopy

Efficacy of cap-assisted colonoscopy according to lesion location and endoscopist training level

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World Journal of Gastroenterology 2015年第20期21卷 6261-6270页

作者： Dong Jun Kim Hyung Wook Kim Su Bum Park Dae Hwan Kang Cheol Woong Choi Joung Boom Hong Byoung Hoon Ji Chang Seok Lee Department of Internal Medicine Medical Research InstitutePusan National University School of Medicine and Research Institute for Convergence of Biomedical Science and Technology Pusan National University Yangsan Hospital Department of Internal Medicine Dong-eui Medical Center Department of Internal Medicine Bongseng Memorial Hospital

AIM: To evaluate the efficacy of cap-assisted colonoscopy(CAC) for detection of colorectal polyps and adenomas according to the lesion location and endoscopist training ***: Patients 20 years or older, who underwent their first screening colonoscopy in a single tertiary center from May 2011 to December 2012 were enrolled in this study. All patients underwent either CAC or standard colonoscopy(SC), and all of the procedures were performed by 11 endoscopists(8 trainees and 3 experts). All procedures were performed with highdefinition colonoscopes and narrow band imaging. The eight trainees had experiences of performing 150 to 500 colonoscopies, and the three experts had experiences of performing more than 3000 colonoscopies. A 4-mmlong transparent cap was attached to the end of a colonoscope in the CAC group. We retrospectively evaluated the number of polyps and adenomas, polyp detection rate(PDR), and the number of adenomas and adenoma detection rate(ADR) according to the lesion location and endoscopist training level between CAC and SC. We also evaluated the number of polyps and adenomas according to their size between CAC and ***: Overall, PDR and ADR using CAC were significantly higher than those using SC for both whole colon(48.5% vs 40.7%, P = 0.012; 35.7% vs 28.3%, P = 0.012) and right-side colon(35.3% vs 26.6%, P = 0.002; 27.0% vs 16.9%, P < 0.001). The number of polyps and adenomas per patient using CAC was significantly higher than that using SC for both the whole colon(1.07 ± 1.59 vs 0.82 ± 1.31, P = 0.008; 0.72 ± 1.32 vs 0.50 ± 1.01, P = 0.003) and right-side colon(0.66 ± 1.18 vs 0.41 ± 0.83, P < 0.001; 0.46 ± 0.97 vs 0.25 ± 0.67, P < 0.001). In the trainee group, the PDR and ADR using CAC were significantly higher than those using SC for both the whole colon(46.7% vs 39.7%, P = 0.040; 33.9% vs 26.0%, P =0.012) and right-side colon(34.2% vs 26.5%, P = 0.015; 25.3% vs 15.9%, P = 0.001). In the expert group, the PDR and ADR using CAC were si

关键词： Colonoscopy Cap-assisted colonoscopy Colonic polyps Adenoma Colorectal neoplasm

Customizable design ofmultiple-biomolecule delivery platform for enhanced osteogenic responses via‘tailored assembly system’

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Bio-Design and Manufacturing 2022年第3期5卷 451-464页

作者： Hyun Lee Min-Kyu Lee Ginam Han Hyoun-Ee Kim Juha Song Yuhyeon Na Chang-Bun Yoon SeKwon Oh Tae-Sik Jang Hyun-Do Jung Department of biomedical-Chemical Engineering Catholic University of KoreaBucheon 14662Republic of Korea Department of Biotechnology The Catholic University of KoreaBucheon 14662Republic of Korea Department of Materials Science and Engineering Seoul National UniversitySeoul 08826Republic of Korea Querrey Simpson Institute for Bioelectronics Northwestern UniversityEvanstonIL 60208USA biomedical implant convergence research center Advanced Institutes of Convergence TechnologySuwon 443-270Republic of Korea School of Chemical and biomedical Engineering Nanyang Technological University70 Nanyang DriveSingapore 637457Singapore Department of Advanced Materials Engineering Korea Polytechnic UniversitySiheung-siGyeonggi-do 15073Republic of Korea Surface R&D Group Korea Institute of Industrial TechnologyIncheon 21999Republic of Korea Department of Materials Science and Engineering Chosun UniversityGwangju 61452Republic of Korea

Porous titanium(Ti)scaffolds have been extensively utilized as bone substitute scaffolds due to their superior biocompatibility and excellent mechanical ***,naturally formed TiO2 on the surface limits fast *** biomolecules have been widely utilized to overcome this issue;however,homogeneous porous Ti scaffolds could not simultaneously deliver multiple biomolecules that have different release *** this study,functionally graded porous Ti scaffolds(FGPTs)with dense inner and porous outer parts were fabricated using a two-body combination and densification *** with growth factor(BMP-2)and antibiotics(TCH)exhibited suitable mechanical properties as bone substituting material and presented good structural *** release of BMP-2 was considerably prolonged,whereas the release of TCH was comparable to that of homogenous porous titanium scaffolds(control group).The osteogenic differentiation obtained using FGPTs was maintained due to the prolonged release of *** antimicrobial properties of these scaffolds were verified using *** in terms of prior release *** addition,various candidates for graded porous Ti scaffolds with altered pore characteristics were presented.

关键词： Functionally graded porous titanium scaffold Tailored assembly system Mechanical tunability Multiplebiomolecule delivery Bone tissue engineering