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Structural Color Dynamic Graphics Display Based on Microlens Array 被引量:1
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作者 LI Xue-han LIU Ling-zhi +1 位作者 HUANG Min LI Xiu 《印刷与数字媒体技术研究》 北大核心 2025年第2期162-168,共7页
It is of great scientific significance to construct a 3D dynamic structural color with a special color effect based on the microlens array.However,the problems of imperfect mechanisms and poor color quality need to be... It is of great scientific significance to construct a 3D dynamic structural color with a special color effect based on the microlens array.However,the problems of imperfect mechanisms and poor color quality need to be solved.A method of 3D structural color turning on periodic metasurfaces fabricated by the microlens array and self-assembly technology was proposed in this study.In the experiment,Polydimethylsiloxane(PDMS)flexible film was used as a substrate,and SiO2 microspheres were scraped into grooves of the PDMS film to form 3D photonic crystal structures.By adjusting the number of blade-coated times and microsphere concentrations,high-saturation structural color micropatterns were obtained.These films were then matched with microlens arrays to produce dynamic graphics with iridescent effects.The results showed that by blade-coated two times and SiO2 microsphere concentrations of 50%are the best conditions.This method demonstrates the potential for being widely applied in the anticounterfeiting printing and ultra-high-resolution display. 展开更多
关键词 Structural color Microlens array Dynamic graphics display Moirémagnification Optical anti-counterfeiting
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Magnification:The game changer in dentistry 被引量:1
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作者 Sachin Chauhan Radha Chauhan +1 位作者 Prashant Bhasin Meenu Bhasin 《World Journal of Methodology》 2025年第2期74-82,共9页
During dental examinations and treatments,many dentists are using magni-fication to improve their vision.The dental operating microscope serves as the most effective tool for this purpose,enhancing the quality,longevi... During dental examinations and treatments,many dentists are using magni-fication to improve their vision.The dental operating microscope serves as the most effective tool for this purpose,enhancing the quality,longevity,and outcome of clinical work.This review will explore the latest research and data on the importance of magnification devices in dentistry,including diagnostic methods,treatment options and ergonomics in specialities such as restorative dentistry,endodontics,pedodontics,periodontics,and prosthodontics.This review aims to provide insights into the optimal magnification for different clinical situations,the specific benefits of dental operating microscopes for each dental branch,and their limitations. 展开更多
关键词 MAGNIFICATION VISION ENDODONTICS DENTISTRY Dental operating microscope
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IDSSCNN-XgBoost:Improved Dual-Stream Shallow Convolutional Neural Network Based on Extreme Gradient Boosting Algorithm for Micro Expression Recognition
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作者 Adnan Ahmad Zhao Li +1 位作者 Irfan Tariq Zhengran He 《Computers, Materials & Continua》 SCIE EI 2025年第1期729-749,共21页
Micro-expressions(ME)recognition is a complex task that requires advanced techniques to extract informative features fromfacial expressions.Numerous deep neural networks(DNNs)with convolutional structures have been pr... Micro-expressions(ME)recognition is a complex task that requires advanced techniques to extract informative features fromfacial expressions.Numerous deep neural networks(DNNs)with convolutional structures have been proposed.However,unlike DNNs,shallow convolutional neural networks often outperform deeper models in mitigating overfitting,particularly with small datasets.Still,many of these methods rely on a single feature for recognition,resulting in an insufficient ability to extract highly effective features.To address this limitation,in this paper,an Improved Dual-stream Shallow Convolutional Neural Network based on an Extreme Gradient Boosting Algorithm(IDSSCNN-XgBoost)is introduced for ME Recognition.The proposed method utilizes a dual-stream architecture where motion vectors(temporal features)are extracted using Optical Flow TV-L1 and amplify subtle changes(spatial features)via EulerianVideoMagnification(EVM).These features are processed by IDSSCNN,with an attention mechanism applied to refine the extracted effective features.The outputs are then fused,concatenated,and classified using the XgBoost algorithm.This comprehensive approach significantly improves recognition accuracy by leveraging the strengths of both temporal and spatial information,supported by the robust classification power of XgBoost.The proposed method is evaluated on three publicly available ME databases named Chinese Academy of Sciences Micro-expression Database(CASMEII),Spontaneous Micro-Expression Database(SMICHS),and Spontaneous Actions and Micro-Movements(SAMM).Experimental results indicate that the proposed model can achieve outstanding results compared to recent models.The accuracy results are 79.01%,69.22%,and 68.99%on CASMEII,SMIC-HS,and SAMM,and the F1-score are 75.47%,68.91%,and 63.84%,respectively.The proposed method has the advantage of operational efficiency and less computational time. 展开更多
关键词 ME recognition dual stream shallow convolutional neural network euler video magnification TV-L1 XgBoost
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Present status and future directions:Apexification
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作者 Sachin Chauhan Radha Chauhan +1 位作者 Prashant Bhasin Bhavna G Sharaf 《World Journal of Methodology》 2025年第1期26-32,共7页
The success rate of apexification is primarily determined by multiple factors,including the material used,the size of the open apex compared to the length of the root,and the technique used in each case.The main objec... The success rate of apexification is primarily determined by multiple factors,including the material used,the size of the open apex compared to the length of the root,and the technique used in each case.The main objective of this review was to provide an update on the present management of open apex to identify factors and circumstances that may influence the success of apexification using different materials and techniques.Future research on apexification should focus on how to treat open apices with wide periapical lesions without surgery.Previously,the predictability of these parameters with non-surgical procedures was uncertain,but now,with the use of a dental operating microscope,it has become more predictable.Another reason could be that extra visits are no longer required due to major advances in the armamentarium and materials used for apexification. 展开更多
关键词 BIOCERAMICS MAGNIFICATION Biodentine Mineral trioxide aggregate APEXIFICATION Open apex
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Precision at the apex:Apexification under magnification:A case report
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作者 Radha Chauhan Sachin Chauhan +4 位作者 Prashant Bhasin Ashima Sood Hemanshi Kumar Ajay Gupta Meenu Bhasin 《World Journal of Methodology》 2025年第4期417-424,共8页
BACKGROUND Advanced materials and techniques are used to successfully manage the apexification of immature teeth with open apices.The use of mineral trioxide aggregate(MTA),bioceramic sealers,and sodium hypochlorite(N... BACKGROUND Advanced materials and techniques are used to successfully manage the apexification of immature teeth with open apices.The use of mineral trioxide aggregate(MTA),bioceramic sealers,and sodium hypochlorite(NaOCl),combined with internal heating and ultrasonic activation,ensures that canals are cleaned,disinfected,and sealed properly.Magnification devices,such as dental operating microscopes(DOM),provide precise visualization for accurate material placement,while the micro apical placement system ensures void-free MTA delivery.This modern approach improves procedural outcomes,lowers iatrogenic errors,and increases long-term success in apexification,making it a dependable and predictable treatment option for immature teeth.CASE SUMMARY Apexification is a regenerative endodontic procedure that involves creating a calcified barrier at the apex of a nonvital tooth with an open apex.This technique is commonly used in immature teeth with necrotic pulps to ensure proper root canal sealing.Traditionally,calcium hydroxide was the preferred material,but advances have introduced bioceramic cements like MTA or Biodentine,which provide superior results with less treatment time.Apexification not only helps to maintain the tooth's structural integrity but also prevents further complications,making it an important procedure in such cases.CONCLUSION This case demonstrates the effectiveness of integrating advanced materials,precise irrigation protocols,and magnification tools in the apexification of immature teeth with open apices.The use of MTA created a stable apical barrier,while bioceramic sealers enhanced the seal and promoted long-term healing.NaOCl with internal heating,ultrasonic activation,and double-sided vented needles ensured thorough irrigation and disinfection,especially in complex canal anatomy. 展开更多
关键词 BIOCERAMICS MAGNIFICATION Mineral trioxide aggregate APEXIFICATION IRRIGATION Case report
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Microscopic precision with bioceramics apexification:A case report
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作者 Sachin Chauhan Prashant Bhasin +3 位作者 Radha Chauhan Ashima Sood Jyoti Lamba Prerna Yadav 《World Journal of Clinical Pediatrics》 2025年第4期493-501,共9页
BACKGROUND The management of immature permanent teeth with open apices in pediatric patients presents unique challenges,particularly in cases of nonvital pulp.Modern advancements in materials and techniques have signi... BACKGROUND The management of immature permanent teeth with open apices in pediatric patients presents unique challenges,particularly in cases of nonvital pulp.Modern advancements in materials and techniques have significantly improved the predictability and success of apexification procedures.In this case,a 16-yearold patient presented with an immature necrotic tooth requiring apexification.Contemporary approaches incorporate calcium silicate-based materials such as mineral trioxide aggregate(MTA),Biodentine,and bioceramic putty,along with bioceramic sealers and enhanced canal cleaning including internal heating and ultrasonic activation with sodium hypochlorite(NaOCl)for disinfection,and sealing.Additionally,magnification tools such as dental operating microscopes ensure precise visualization for accurate material placement,while a micro-apical placement(MAP)system guarantees void-free MTA delivery.These advancements improve procedural outcomes and minimize the risk of iatrogenic errors,making apexification a more predictable and reliable treatment option in pediatric patients with immature teeth.CASE SUMMARY A 16-year-old patient presented with a nonvital maxillary central incisor with an open apex,secondary to trauma.Due to the lack of apical closure,traditional root canal obturation was not feasible.Apexification was chosen as the treatment modality to induce the formation of a calcified apical barrier,allowing for proper root canal sealing.Historically,calcium hydroxide was the material of choice for apexification,requiring multiple visits and prolonged treatment duration.However,the introduction of bioceramic materials such as MTA has revolutionized the procedure,offering superior outcomes with reduced treatment time.In this case,the apexification procedure involved thorough canal disinfection using NaOCl,enhanced by internal heating,ultrasonic activation,and double-sided vented needle irrigation.Under the dental operating microscope,MTA was precisely placed at the apex using a MAP system,ensuring a dense,void-free apical barrier.The remaining canal space was subsequently sealed with a bioceramic sealer to promote long-term stability and healing.CONCLUSION This case highlights the effectiveness of a modern approach for apexification in a pediatric patient.The use of advanced materials and techniques facilitated the formation of a stable apical barrier,ensuring long-term tooth retention and function.By incorporating precise irrigation protocols,internal heating,ultrasonic activation,and magnification tools,the treatment achieved thorough disinfection and optimal material placement.These advancements make apexification a predictable and reliable treatment option for young patients with immature necrotic teeth,preserving their natural dentition and preventing future complications. 展开更多
关键词 BIOCERAMICS MAGNIFICATION Mineral trioxide aggregate APEXIFICATION IRRIGATION Case report
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Advancing dental precision:The synergy of magnification and artificial intelligence
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作者 Carlos M Ardila 《World Journal of Methodology》 2025年第4期430-433,共4页
The article by Chauhan et al highlights the transformative potential of magnification tools in improving precision and outcomes across various dental specialties.While the authors discuss the advantages of magnificati... The article by Chauhan et al highlights the transformative potential of magnification tools in improving precision and outcomes across various dental specialties.While the authors discuss the advantages of magnification,they do not address the potential integration of artificial intelligence(AI)with magnification devices to further enhance diagnostic and therapeutic efficiency.This letter explores the synergy of AI with magnification tools,emphasizing its applicability in image-guided diagnostics,workflow optimization,and personalized treatment planning.The integration of AI and magnification also paves the way for personalized,data-driven treatment strategies,marking a significant evolution in dental care.However,it is important to acknowledge the limitations and challenges associated with AI,such as data privacy concerns,algorithmic biases,and the need for robust validation before clinical implementation.This discussion underscores the need for interdisciplinary research to realize this potential. 展开更多
关键词 Artificial intelligence Dental magnification Diagnostic imaging Workflow optimization Personalized treatment planning DENTISTRY
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Fractal dimension for porous metal materials of FeCrAl fiber 被引量:1
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作者 王建忠 奚正平 +3 位作者 汤慧萍 黄卫东 朱纪磊 敖庆波 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第4期1046-1051,共6页
The FeCrA1 fiber was used to prepare porous metal materials with air-laid technology, and then followed by sintering at 1300 ℃ for a holding period of 2 h in the vacuum. In addition, a novel fractal soft, which was d... The FeCrA1 fiber was used to prepare porous metal materials with air-laid technology, and then followed by sintering at 1300 ℃ for a holding period of 2 h in the vacuum. In addition, a novel fractal soft, which was developed based on the fractal theory and the computer image processing technology, was explored to describe the pore structure of porous metal materials. Furthermore, the fractal dimension of pore structure was calculated by the soft and the effects of magnification and porosity on ffactal dimension were also discussed. The results show that the fractal dimension decreases with increase in the magnification, while it increases continuously with the porosity enhancing. The interrelationship between the fractal dimension and the magnification or porosity can be presented by the equation of D=α_0exp(-x/α_1)+α_2和D=k_2-(k_1-k_2)/[1+exp((θ-k_0)/k_3)], respectively. 展开更多
关键词 porous metal materials FeCrA1 fiber fractal dimension POROSITY MAGNIFICATION
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Construction analysis on integral lifting of steel structure by the vector form intrinsic finite element 被引量:3
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作者 朱明亮 陈雪琪 郭正兴 《Journal of Southeast University(English Edition)》 EI CAS 2016年第4期451-456,共6页
A newnumerical method based on vector form intrinsic finite element(VFIFE) is proposed to simulate the integral lifting process of steel structures. First, in order to verify the validity of the VFIFE method, taking... A newnumerical method based on vector form intrinsic finite element(VFIFE) is proposed to simulate the integral lifting process of steel structures. First, in order to verify the validity of the VFIFE method, taking the steel gallery between the integrated building and the attached building of Nanjing M obile Communication Buildings for example, the static analysis was carried out and the corresponding results were compared with the results achieved by the traditional finite element method. Then, according to the characteristics of dynamic construction of steel structure integral lifting, the tension cable element was employed to simulate the behavior of dynamic construction. The VFIFE method avoids the iterative solution of the stiffness matrix and the singularity problems. Therefore, it is simple to simulate the complete process of steel structure lifting construction.Finally, by using the VFIFE, the displacement and internal force time history curves of the steel structures under different lifting speeds are obtained. The results show that the lifting speed has influence on the lifting force, the internal force, and the displacement of the structure. In the case of normal lifting speed, the dynamic magnification factor of 1. 5 is safe and reasonable for practical application. 展开更多
关键词 integral lifting vector form intrinsic finite element(VFIFE) steel gallery whole process of construction dynamic magnification factor
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Diameter Measurements of the Upper Parts of Trees Using an Ultra-Telephoto Digital Photography System
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作者 Akira Shimizu Shigeki Yamada Yuichiro Arita 《Open Journal of Forestry》 2014年第4期316-326,共11页
We develop a new technique to measure the exact upper diameters of trees that is comparatively simple and inexpensive. We can measure the diameters of entire tree trunks efficiently and with high precision. The system... We develop a new technique to measure the exact upper diameters of trees that is comparatively simple and inexpensive. We can measure the diameters of entire tree trunks efficiently and with high precision. The system uses a digital camera with a ~15 - 30× telephoto lens to take a photograph that can be used for measuring the diameter of the upper part of a comparatively slender tree trunk. Since this method requires a measuring distance and the height of the target point in the image, a range finder capable of measuring angles was combined with the main digiscoping system. A range finder sensor uses a laser and makes a 360 degree angle of observation possible. The diameter of a target position of the objective tree can be obtained by measuring the digital image using image editing software and calculations from spreadsheet software. We focus on the Japanese cedar species in the southwestern part of Japan. Photographic measurements were obtained prior to thinning. The estimates that we obtained largely agree with the true measurements of all trees. With regard to the estimated accuracy of all measured trees, the maximum error ratio was 7.0% (1.45 cm), with a ~2% - 4% error for most of the estimated results. Although the absolute value of the estimation error was 1.87 cm (5.3%) at the maximum (9.87 m in height and 35.5 cm in diameter), an estimation accuracy of <1 cm was reproduced in almost all measurements except for the extreme hypertrophy portion by butt swelling. 展开更多
关键词 Digital Camera Image EDITING Software magnifications Spotting SCOPE TAPER Curve UPPER Diameter
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Narrow-band imaging with magnifying endoscopy is accurate for detecting gastric intestinal metaplasia 被引量:24
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作者 Edoardo Savarino Marina Corbo +5 位作者 Pietro Dulbecco Lorenzo Gemignani Elisa Giambruno Luca Mastracci Federica Grillo Vincenzo Savarino 《World Journal of Gastroenterology》 SCIE CAS 2013年第17期2668-2675,共8页
AIM:To investigate the predictive value of narrowband imaging with magnifying endoscopy (NBI-ME) for identifying gastric intestinal metaplasia (GIM) in unselected patients. METHODS:We prospectively evaluated consecuti... AIM:To investigate the predictive value of narrowband imaging with magnifying endoscopy (NBI-ME) for identifying gastric intestinal metaplasia (GIM) in unselected patients. METHODS:We prospectively evaluated consecutive patients undergoing upper endoscopy for various indications, such as epigastric discomfort/pain, anaemia, gastro-oesophageal reflux disease, suspicion of peptic ulcer disease, or chronic liver diseases. Patients underwent NBI-ME, which was performed by three blinded, experienced endoscopists. In addition, five biopsies (2 antrum, 1 angulus, and 2 corpus) were taken and examined by two pathologists unaware of the endoscopic findings to determine the presence or absence of GIM. The correlation between light blue crest (LBC) appearance and histology was measured. Moreover, we quantified the degree of LBC appearance as less than 20% (+), 20%-80% (++) and more than 80% (+++) of an image field, and the semiquantitative evaluation of LBC appearance was correlated with IM percentage from the histological findings. RESULTS:We enrolled 100 (58 F/42 M) patients who were mainly referred for gastro-esophageal reflux disease/dyspepsia (46%), cancer screening/anaemia (34%), chronic liver disease (9%), and suspected celiac disease (6%); the remaining patients were referred for other indications. The prevalence of Helicobacter pylori (H. pylori ) infection detected from the biopsies was 31%, while 67% of the patients used proton pump inhibitors. LBCs were found in the antrum of 33 patients (33%); 20 of the cases were classified as LBC+, 9 as LBC++, and 4 as LBC+++. LBCs were found in the gastric body of 6 patients (6%), with 5 of them also having LBCs in the antrum. The correlation between the appearance of LBCs and histological GIM was good, with a sensitivity of 80% (95%CI:67-92), a specificity of 96% (95%CI:93-99), a positive predictive value of 84% (95%CI:73-96), a negative predictive value of 95% (95%CI:92-98), and an accuracy of 93% (95%CI:90-97). The NBI-ME examination overlooked GIM in 8 cases, but the GIM was less than 5% in 7 of the cases. Moreover, in the 6 false positive cases, the histological examination showed the presence of reactive gastropathy (4 cases) or H. pylori active chronic gastritis (2 cases). The semiquantitative correlation between the rate of LBC appearance and the percentage of GIM was 79% (P < 0.01). CONCLUSION:NBI-ME achieved good sensitivity and specificity in recognising GIM in an unselected population. In routine clinical practice, this technique can reliably target gastric biopsies. 展开更多
关键词 NARROW-BAND imaging MAGNIFICATION GASTRIC intestinal METAPLASIA Light blue CREST GASTRIC cancer Endoscopy PRECANCEROUS conditions GASTRIC biopsy
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Clinical significance of type V_I pit pattern subclassification in determining the depth of invasion of colorectal neoplasms 被引量:17
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作者 Hiroyuki Kanao Shinji Tanaka +5 位作者 Shiro Oka Iwao Kaneko Shigeto Yoshida Koji Arihiro Masaharu Yoshihara Kazuaki Chayama 《World Journal of Gastroenterology》 SCIE CAS CSCD 2008年第2期211-217,共7页
AIM: To clarify whether subclassification of the type VI pit pattern on the basis of magnifying colonoscopy findings is useful in determining the type and depth of invasion of colorectal neoplasms.METHODS: We retrospe... AIM: To clarify whether subclassification of the type VI pit pattern on the basis of magnifying colonoscopy findings is useful in determining the type and depth of invasion of colorectal neoplasms.METHODS: We retrospectively analyzed 272 colorectal neoplasms (117 dysplasias and 155 submucosal invasive carcinomas; 228 patients) with a type V pit pattern [type VI, n = 202; type VN, n = 70 (Kudo and Tsuruta classification system)]. We divided lesions with a type VI pit pattern into two subclasses, mildly irregular lesions and severely irregular lesions, according to the prominent and detailed magnifying colonoscopy findings. We examined the relation between these two subclasses and histology/invasion depth.RESULTS: One hundred and four lesions (51.5%) were judged to be mildly irregular, and 98 lesions (48.5%) were judged to be severely irregular. Ninety-seven (93.3%) mildly irregular lesions showed dysplasias or submucosal invasion of less than 1000 μm (SM < 1000 μm). Fifty-five (56.1%) severely irregular lesions showed submucosal invasion equal to or deeper than 1000 μm (SM ≥ 1000 μm). Mild irregularity was found significantly more often in dysplasias or lesions with SM < 1000 μm than in lesions with SM ≥ 1000 μm (P < 0.01).CONCLUSION: Subclassification of the type VI pit pattern is useful for identifying dysplasias or lesions with SM < 1000 μm. 展开更多
关键词 Colorectal neoplasm MAGNIFICATION Type VI pit pattern Depth of invasion
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SEM-backscattered Electron Imaging and Image Processing for Evaluation of Unhydrated Cement Volume Fraction in Slag Blended Portland Cement Pastes 被引量:9
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作者 丰曙霞 王培铭 LIU Xianping 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2013年第5期968-972,共5页
Proper parameters for image taking and minimum field number for image processing were investigated to evaluate volume fraction of unhydrated cement(UHC) in both neat cement paste and slag blended cement paste. Our r... Proper parameters for image taking and minimum field number for image processing were investigated to evaluate volume fraction of unhydrated cement(UHC) in both neat cement paste and slag blended cement paste. Our research suggested that magnification 250x was sufficient for the two pastes, and accelerating voltage should be set as 15 kV and 20 kV for BSE image taking of neat cement paste and slag blended cement paste respectively; the minimum field number increased while the total imaging area stayed the same as the magnification increased within certain statistical bias. 展开更多
关键词 accelerating voltage MAGNIFICATION grey level histogram statistical analysis total imaging area
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Clinical applicability of gastroscopy with narrow-band imaging for the diagnosis of Helicobacter pylori gastritis, precancerous gastric lesion, and neoplasia 被引量:11
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作者 Jun-Hyung Cho Seong Ran Jeon So-Young Jin 《World Journal of Clinical Cases》 SCIE 2020年第14期2902-2916,共15页
Premalignant gastric lesions such as atrophic gastritis and intestinal metaplasia frequently occur in subjects with long-term Helicobacter pylori(H.pylori)infection.The regular arrangement of collecting venules(RAC)is... Premalignant gastric lesions such as atrophic gastritis and intestinal metaplasia frequently occur in subjects with long-term Helicobacter pylori(H.pylori)infection.The regular arrangement of collecting venules(RAC)is seen in the normal gastric corpus,whereas mucosal swelling and redness without RAC are observed in H.pylori-infected mucosa.Despite successful H.pylori eradication,the presence of atrophic gastritis and/or gastric intestinal metaplasia(GIM)is a risk factor for gastric cancer.With the development of advanced imaging technologies,recent studies have reported the usefulness of narrow-band imaging(NBI)for endoscopic diagnosis of atrophic gastritis and GIM.Using NBI endoscopy with magnification(M-NBI),atrophic gastritis is presented as irregular coiled microvessels and loss of gastric pits.Typical M-NBI endoscopic findings of GIM are a light blue crest and a white opaque substance.Based on the microvascular patterns,fine network,core vascular,and unclear patterns are useful for predicting gastric dysplasia in polypoid lesions.For diagnosis of early gastric cancer(EGC),a systematic classification using M-NBI endoscopy has been proposed on the basis of the presence of a demarcation line and an irregular microvascular/microsurface pattern.Furthermore,M-NBI endoscopy has been found to be more accurate for determining the horizontal margin of EGC compared to conventional endoscopy.In this review,we present up-to-date results on the clinical usefulness of gastroscopy with NBI for the diagnosis of H.pylori gastritis,precancerous gastric lesion,and neoplasia. 展开更多
关键词 GASTROSCOPY Narrow-band imaging MAGNIFICATION Helicobacter pylori Atrophic gastritis Intestinal metaplasia Dysplasia Cancer
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Research on vibration suppression of a mistuned blisk by a piezoelectric network 被引量:6
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作者 Jiuzhou LIU Lin LI +1 位作者 Yu FAN Pengcheng DENG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2018年第2期285-299,共15页
The work aims to provide a further investigation of the dynamic characteristics of an integral bladed disk(also called ‘blisk') with a Parallel Piezoelectric Network(PPN). The PPN is constructed by parallelly in... The work aims to provide a further investigation of the dynamic characteristics of an integral bladed disk(also called ‘blisk') with a Parallel Piezoelectric Network(PPN). The PPN is constructed by parallelly interconnecting the piezoelectric patches distributed in the blisk. Two kinds of PPN are considered, namely mono-periodic PPN and bi-periodic PPN. The former has a piezoelectric patch in each sector, and the later has one patch every few sectors. The vibration suppression performance of both kinds of PPN has been studied through modal analysis, forced response analysis, and statistical analysis. The research results turn out that the PPN will only affect mechanical frequencies near the electrical frequency clusters slightly, and the bi-periodic PPN will make the nodal diameter spectrum of the modes more complex, but the amplitude corresponding to the new nodal diameter component is much smaller than that of the nodal diameter component corresponding to the mono-periodic system. The mechanical coupling between the blades and the disk plays an important role in the damping effect of the PPN, and it should be paid attention to in applications. The mono-periodic PPN can effectively suppress the amplitude magnification of the forced response induced by the mistuning of the blisk; meanwhile, it can mitigate the vibration localization of the mistuned electromechanical system. If piezoelectric patches are set only in part of the sectors, the bi-periodic PPN still has a vibration suppression ability, but the effect is related to the number and spatial distribution of the piezoelectric patches. 展开更多
关键词 Amplitude magnification Bi-periodic BLISK Mistuning Mono-periodic Parallel piezoelectric network Statistical analysis Vibration suppression
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Endoscopic features of early-stage signet-ring-cell carcinoma of the stomach 被引量:11
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作者 Chainarong Phalanusitthepha Kevin L Grimes +4 位作者 Haruo Ikeda Hiroki Sato Chiaki Sato Chananya Hokierti Haruhiro Inoue 《World Journal of Gastrointestinal Endoscopy》 CAS 2015年第7期741-746,共6页
AIM: To identify the features of early signet ring cell gastric carcinoma using magnification endoscopy with narrow band imaging(NBI).METHODS: A retrospective review was conducted of 12 cases of early signet ring cell... AIM: To identify the features of early signet ring cell gastric carcinoma using magnification endoscopy with narrow band imaging(NBI).METHODS: A retrospective review was conducted of 12 cases of early signet ring cell gastric carcinoma who underwent treatment in a single institution between January 2009 and April 2013. All patients had magnification endoscopy with NBI and indigo carmine contrast to closely examine the mucosal architecture, including the microvasculature and arrangement of gastric pits. Histologic examination of the final endoscopic submucosal dissection or gastrectomy specimen was performed and compared with the endoscopic findings to identify patterns specific to signet ring cell carcinoma.RESULTS: Twelve patients with early signet ring cell gastric carcinoma were identified; 75% were male, and average age was 61 years. Most of the lesions were stage T1a(83%), while the remainder were T1b(17%). The mean lesion size was 1.4 cm2. On standard endoscopy, all 12 patients had a pale, flat lesion without any evidence of mucosal abnormality such as ulceration, elevation, or depression. On magnification endoscopywith NBI, all of the patients had irregularities in the glands and microvasculature consistent with early gastric cancer. In addition, all 12 patients exhibited the "stretch sign", an elongation or expansion of the architectural structure. Histologic examination of the resected specimens demonstrated an expanded and edematous mucosal layer infiltrated with tumor cells.CONCLUSION: The "stretch sign" appears to be specific for signet ring cell carcinoma and may aid in the early diagnosis and treatment of this aggressive pathology. 展开更多
关键词 Signet ring cells Early gastric cancer Magnification endoscopy Narrow band imaging Stretchsign Endoscopic submucosal dissection
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White light endoscopy,narrow band imaging and chromoendoscopy with magnification in diagnosing colorectal neoplasia 被引量:3
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作者 Rajvinder Singh Victoria Owen +3 位作者 Anthony Shonde Philip Kaye Christopher Hawkey Krish Ragunath 《World Journal of Gastrointestinal Endoscopy》 CAS 2009年第1期45-50,共6页
AIM:To evaluate the sensitivity(Sn),specificity(Sp),positive predictive value(PPV) and negative predictive value(NPV) of 3 different techniques:high resolution white light endoscopy(WLE),Narrow Band Imaging(NBI) and C... AIM:To evaluate the sensitivity(Sn),specificity(Sp),positive predictive value(PPV) and negative predictive value(NPV) of 3 different techniques:high resolution white light endoscopy(WLE),Narrow Band Imaging(NBI) and Chromoendoscopy(CHR),all with magnification in differentiating adenocarcinomas,adenomatous and hyperplastic colorectal polyps.METHODS:Each polyp was sequentially assessed first by WLE,followed by NBI and finally by CHR.Digital images of each polyp with each modality were taken and stored.Biopsies or polypectomies were then performed followed by blinded histopathological analysis.Each image was blindly graded based on the Kudo's pit pattern(KPP).In the assessment with NBI,the mesh brown capillary network pattern(MBCN) of each polyp was also described.The Sn,Sp,PPV and NPV of differentiating hyperplastic(Type Ⅰ & Ⅱ-KPP,Type Ⅰ-MBCN) adenomatous(Types Ⅲ,Ⅳ-KPP,Type Ⅱ-MBCN) and carcinomatous polyps(Type Ⅴ-KPP,Type Ⅲ-MCBN) was then compared with reference to the final histopathological diagnosis.RESULTS:A total of 50 colorectal polyps(5 adenocarcinomas,38 adenomas,7 hyperplastic) were assessed.CHR and NBI [KPP,MBCN or the combined classification(KPP & MBCN)] were superior to WLE in the prediction of polyp histology(P < 0.001,P=0.002,P=0.001 and P < 0.001,respectively).NBI,using the MBCN pattern or the combined classification showed higher numerical accuracies compared to CHR,but this was not statistically significant(P=0.625,0.250).CONCLUSION:This feasibility study demonstrated that this combined classification with NBI could potentially be useful in routine clinical practice,allowing the endoscopist to predict histology with higher accuracies using a less cumbersome and technically less challenging method. 展开更多
关键词 High-resolution MAGNIFICATION ENDOSCOPY Narrow band imaging with MAGNIFICATION CHROMOENDOSCOPY with MAGNIFICATION COLORECTAL POLYP COLORECTAL NEOPLASIA
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Real-time histology with the endocytoscope 被引量:3
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作者 Rajvinder Singh Swee Lin Chen Yi Mei +2 位作者 William Tam Devinder Raju Andrew Ruszkiewicz 《World Journal of Gastroenterology》 SCIE CAS CSCD 2010年第40期5016-5019,共4页
Endoscopic Imaging has progressed tremendously over the last few decades. Novel imaging technologies such as high-resolution and high-magnification white light endoscopy, narrow band imaging, optimal band imaging, aut... Endoscopic Imaging has progressed tremendously over the last few decades. Novel imaging technologies such as high-resolution and high-magnification white light endoscopy, narrow band imaging, optimal band imaging, auto? ourescence imaging and optical coherence tomography not only aid the endoscopist in detecting malignant or pre-malignant lesions but also assist in predicting histology. Recently, the introduction of Endocytoscopy (EC) and Confocal Endomicroscopy has taken us into a new realm of diagnostic endoscopy. With the ability to magnify up to 1000 ×, cellular structures can be visualized in real-time. This advance in technology could potentially lead to a paradigm shift negating the need to obtain biopsies. EC is, however, still in the early stages of development and further research needs to be carried out before it can be accepted as standard practice. This review will focus on the diagnostic utility of the Endocytoscope. 展开更多
关键词 ENDOCYTOSCOPY Advanced endoscopy imaging Magnification endoscopy Real-time histology
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Diagnosis of autoimmune gastritis by high resolution magnification endoscopy 被引量:3
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作者 George K Anagnostopoulos Krish Ragunath +1 位作者 Anthony Shonde Christopher J Hawkey 《World Journal of Gastroenterology》 SCIE CAS CSCD 2006年第28期4586-4587,共2页
Endoscopic visualisation of gastric atrophy is usually not feasible with conven.tional endoscopy. Magnifying endoscopy is helpful to analyze the subepithelial microvascular architecture as well as the mucosal surface ... Endoscopic visualisation of gastric atrophy is usually not feasible with conven.tional endoscopy. Magnifying endoscopy is helpful to analyze the subepithelial microvascular architecture as well as the mucosal surface microstructure without tissue biopsy. Using this technique we were able to describe the normal gastric microvasculature pattern and we also identified characteristic patterns in two cases of autoimmune atrophic gastritis. 展开更多
关键词 Magnification endoscopy Autoimmune gastritis Collecting venules Subepithelial capillary network
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AN IMAGE MAGNIFICATION ALGORITHM USING THE GVF CONSTRAINT MODEL 被引量:4
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作者 Li Xiaoguang Lam Kin-Man Shen Lansun 《Journal of Electronics(China)》 2008年第4期568-571,共4页
An image magnification method with a Gradient Vector Flow(GVF)constraint-basedanisotropic diffusion model is proposed in this letter.A Low-Resolution(LR)image is first magnifiedusing bilinear interpolation,and then an... An image magnification method with a Gradient Vector Flow(GVF)constraint-basedanisotropic diffusion model is proposed in this letter.A Low-Resolution(LR)image is first magnifiedusing bilinear interpolation,and then an iterative image restoration method,with the use of an ani-sotropic diffusion model and a Gaussian moving-average constraint,is applied to the magnified image.The estimated GVF of a High-Resolution(HR)image can be used to remove the jagged effect and topreserve the textural structure in the image.Meanwhile,the use of the Gaussian moving-average LRmodel can provide a data fidelity constraint,which renders a magnified image closer to the ideal HRversion.Experimental results show that the proposed method can improve the quality of magnifiedimages in terms of both objective and subjective criteria. 展开更多
关键词 Image magnification Super resolution Anisotropic diffusion Gradient-Vector Flow (GVF)
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