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
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
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
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
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
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
AIM: To compare the yield of adenomas between narrow band imaging and white light when using high definition/magnification. METHODS: This prospective, non-randomized comparative study was performed at the endoscopy un...AIM: To compare the yield of adenomas between narrow band imaging and white light when using high definition/magnification. METHODS: This prospective, non-randomized comparative study was performed at the endoscopy unit of veteran affairs medical center in Phoenix, Arizona. Consecutive patients undergoing first average risk colorectal cancer screening colonoscopy were selected. Two experienced gastroenterologists performed all the procedures that were blinded to each other's findings. Demographic details were recorded. Data are presented as mean ± SEM. Proportional data were compared using the χ2 test and means were compared using the Student's t test. Tandem colonoscopy was performed in a sequential and segmental fashion using one of 3 strategies: white light followed by narrow band imaging [Group A: white light(WL) → narrow band imaging(NBI)]; narrow band imaging followed by white light(Group B: NBI → WL) and, white light followed by white light(Group C: WL → WL). Detection rate of missed polyps and adenomas were evaluated in all three groups. RESULTS: Three hundred patients were studied(100 in each Group). Although the total time for the colonoscopy was similar in the 3 groups(23.8 ± 0.7, 22.2 ± 0.5 and 24.1 ± 0.7 min for Groups A, B and C, respectively), it reached statistical significance between Groups B and C(P < 0.05). The cecal intubation time in Groups B and C was longer than for Group A(6.5 ± 0.4 min and 6.5 ± 0.4 min vs 4.9 ± 0.3 min; P < 0.05). The withdrawal time for Groups A and C was longer than Group B(18.9 ± 0.7 min and 17.6 ± 0.6min vs 15.7 ± 0.4 min; P < 0.05). Overall miss rate for polyps and adenomas detected in three groups during the second look was 18% and 17%, respectively(P = NS). Detection rate for polyps and adenomas after first look with white light was similar irrespective of the light used during the second look(WL → WL: 13.7% for polyps, 12.6% for adenomas; WL → NBI: 14.2% for polyps, 11.3% for adenomas). Miss rate of polyps and adenomas however was significantly higher when NBI was used first(29.3% and 30.3%, respectively; P < 0.05). Most missed adenomas were ≤ 5 mm in size. There was only one advanced neoplasia(defined by size only) missed during the first look. CONCLUSION: Our data suggest that the tandem nature of the procedure rather than the optical techniques was associated with the detection of additional polyps' and adenomas.展开更多
Endoscopy is an indispensible diagnostic and thera-peutic instrument for gastrointestinal diseases. Endo-cytoscopy and confocal endomicroscopy are two types of ultra high magnification endoscopy techniques.Standard en...Endoscopy is an indispensible diagnostic and thera-peutic instrument for gastrointestinal diseases. Endo-cytoscopy and confocal endomicroscopy are two types of ultra high magnification endoscopy techniques.Standard endoscopy allows for 50 × magnification,whereas endocytoscopy can magnify up to 1400 × and confocal endomicroscopy can magnify up to 1000 ×.These methods open the realm of real time micros copicevaluation of the GI tract, including cellular and subcellular structures. Confocal endomicroscopy has the additional advantage of being able to visualize subsurface structures. The use of high magnification endoscopy inconjunction with standard endoscopy allows for a real-time microscopic assessment of areas with macroscopic abnormalities, providing "virtual biopsies" with valuable information about cellular and subcellular changes. Thiscan minimize the number of biopsies taken at the time of endoscopy. The use of this technology may assistin detecting premalignant or malignant changes at anearlier state, allowing for earlier intervention and treatment. High magnification endoscopy has shown promising results in clinical trials for Barrett's esophagus,esophageal adenocarcinoma, esophageal squamous cell cancer, gastric cancer, celiac disease, colorectalcancer, and inflammatory bowel disease. As the use of high magnification endoscopy techniques increases,the clinical applications will increase as well. Of the two systems, only confocal endomicroscopy is currently commercially available. Like all new technologies there will be an initial learning curve before operators become proficient in obtaining high quality images and discerning abnormal from normal pathology. Validatedcriteria for the diagnosis of the various gastrointestinal diseases will need to be developed for each method. Inthis review, the basic principles of both modalities are discussed, along with their clinical applic ability and limitations.展开更多
Russell body gastritis(RBG) is an unusual type of chronic gastritis characterized by marked infiltration of Mott cells,which are plasma cells filled with spherical eosinophilic bodies referred to as Russell bodies.It ...Russell body gastritis(RBG) is an unusual type of chronic gastritis characterized by marked infiltration of Mott cells,which are plasma cells filled with spherical eosinophilic bodies referred to as Russell bodies.It was initially thought that Helicobacter pylori(H.pylori) infection was a major cause of RBG and that the infiltrating Mott cells were polyphenotypic;however,a number of cases of RBG without H.pylori infection or with monoclonal Mott cells have been reported.Thus,diagnostic difficulty exists in distinguishing RBG with monoclonal Mott cells from malignant lymphoma.Here,we report an unusual case of an 86-year-old-Japanese man with H.pylori-positive RBG.During the examination of melena,endoscopic evaluation confirmed a 13-mm whitish,flat lesion in the gastric antrum.Magnification endoscopy with narrowband imaging suggested that the lesion was most likely a poorly differentiated adenocarcinoma.Biopsy findings were consistent with chronic gastritis with many Mott cells with intranuclear inclusions referred to as Dutcher bodies.Endoscopic submucosal dissection confirmed the diagnosis of RBG with kappa-restricted monoclonal Mott cells.Malignant lymphoma was unlikely given the paucity of cytological atypia and Ki-67 immunoreactivity of monoclonal Mott cells.This is the first reported case of RBG with endoscopic diagnosis of malignant tumor and the presence of Dutcher bodies.展开更多
The magnitude of dynamic load produced by high-speed trains depends on many factors,of which train speed is the most critical one.However,it is quite difficult to determine the effect of train speed on dynamic load us...The magnitude of dynamic load produced by high-speed trains depends on many factors,of which train speed is the most critical one.However,it is quite difficult to determine the effect of train speed on dynamic load using the theoretical methods due to the complexity of the interaction between vehicle and track-subgrade.Thus large-scale model test has gradually become an important approach for studying dynamic responses of ballastless track-subgrade of high-speed railway.In this study,a full-scale model of ballastless track-subgrade was constructed in accordance with the design and construction standards for Shanghai-Nanjing intercity high-speed railway line firstly.Then,the dynamic strain of slab and the dynamic earth pressure of subgrade were measured by conducting single wheel axle excitation test.In addition,the relationship between the dynamic load magnification factor（DLF） and the train speed was obtained.Finally,the DLF of track-subgrade under different train speeds was proposed,similar to that given by German Railway Standard.展开更多
AIM： To evaluate the use of web-based technologies to assess the learning curve and reassess reproducibility of a simplified version of a classification for gastric magnification chromoendoscopy （MC）. METHODS： As ...AIM： To evaluate the use of web-based technologies to assess the learning curve and reassess reproducibility of a simplified version of a classification for gastric magnification chromoendoscopy （MC）. METHODS： As part of a multicenter trial, a hybrid approach was taken using a CD-ROM, with 20 films of MC lasting 5 s each and an ＂autorun＂ file triggering a local HTML frameset referenced to a remote questionnaire through an Internet connection. Three endoscopists were asked to prospectively and independently classify 10 of these films randomly selected with at least 3 d apart. The answers were centrally stored and returned to participants together with adequate feedback with the right answer. RESULTS： For classification in 3 groups, both intra- [Cohen＇s kappa （K） = 0.79-1.00 to 0.89-1.00] and inter-observer agreement increased from 1st （moderate） to 6th observation （k = 0.94）. Also, agreement with reference increased in the last observations （0.90, 1.00 and 1.00, for observers A, B and C, respectively）. Validity of 100% was obtained by all observers at their 4th observation. When a 4th （sub）group was considered, inter-observer agreement was almost perfect （K = 0.92） at 6th observation. The relation with reference clearly improved into K （0.93-1.00） and sensitivity （75%-100%） at their 6th observations. CONCLUSION： This MC classification seems to be easily explainable and learnable as shown by excellent intra- and inter-observer agreement, and improved agreement with reference. A web system such as the one used in this study may be useful for endoscopic or other image based diagnostic procedures with respect to definition, education and dissemination.展开更多
A precise zoom magnification is important for semiconductor industry and biomedical research. A novel measurement method is demonstrated for optical zoom magnification measurement in this paper. The magnification is o...A precise zoom magnification is important for semiconductor industry and biomedical research. A novel measurement method is demonstrated for optical zoom magnification measurement in this paper. The magnification is obtained by pattern correction between barcode image formed by optical zoom and reference image generated by an ideal optical model. Measurement accuracy which is better than 0.06% has been achieved for optical zoom magnification. Compared with traditional concept, the measurement results are only dependent on two line edges. The barcode correlation method can achieve higher accuracy and better robustness by using the information over the whole field of view.展开更多
The digital seismometers with high accuracy are installed at depths of -200 m, -100 m in borehole and on the surface in Dongchuan. By analysis of spectra ratio, the local events (with epicentral distances between 8.5 ...The digital seismometers with high accuracy are installed at depths of -200 m, -100 m in borehole and on the surface in Dongchuan. By analysis of spectra ratio, the local events (with epicentral distances between 8.5 km and 95 km, magnitudes ML = 1.3-5.1) recorded are used to calculate site magnification factor at different depths (-100 m and surface) in Dongchuan. Comparing results with that at the depth of -200 m, the site magnification factors at three components of N-S, E-W and U-D corresponding to the depth of -100 m at 8 frequencies (f = 0.75, 1.0, 1.5, 2, 3, 4, 6, and 12 Hz) are 1.0-1.49 when 0.75 Hz- [less-than or equal to] f [less-than or equal to] 2 Hz and 0.47-0.99 when 2 Hz less than or equal f less than or equal 12 Hz. On the surface, site magnification factors at three components are all greater than 1, i.e. between 1.6 and 7.63. The correlation coefficients of site magnification factors for S wave and coda at the depth of -100 m and on surface are 0.82 and 0.81 when 0.75 Hz [less-than or equal to] f [less-than or equal to] 2 Hz, 0.47 and 0.45 when 2 Hz less than or equal f less than or equal 12 Hz, respectively.展开更多
Purpose:The aim of this paper was to examine the distribution of macular,retinal nerve fiber layer(RNFL)thickness and optic disc parameters of myopic and hyperopic eyes in comparison withemmetropic control eyes and to...Purpose:The aim of this paper was to examine the distribution of macular,retinal nerve fiber layer(RNFL)thickness and optic disc parameters of myopic and hyperopic eyes in comparison withemmetropic control eyes and to investigate their variation according to axial length(AL)andspherical equivalent(SE)in healthy children.Methods:This study included 293 pairs of eyes of 293children(145 boys and 148 girks),ranging in age from 6 to 17 years,Subjects were dividedaccording to SE in control(emmetropia,99 children),myopia(100 children)and hyperopia(94children)groups and according to axial AL in 68 short(<22.00 mm,68),medium(from≥22.00 mmto 25.00 mm,189)and long eyes(>25.00 mm,36).Macular parameters,RNFL thickness and opticdisc morphology were assessed by the Cirrus^(TM) HD-OCT.AL was measured using the IOL-Mastersystem.Littmann's formula was used for calculating the corrected AL-related ocular magnification.Results Mean age(±SD)was 10.84±3.05 years;mean(±SD)SE was+0.14±0.51 D(range from8.75 to+8.25 D)and mean AL(±SD)was 23.12±1.49.Average RNFL thickness,averagemacular thickness and macular volume decreased as AL and myopia increased.No correlationsbetween AL/SE and optic disc parameters were found after correcting for magnification effect.Conclusions:AL and refractive error affect measurements of macular and RNFL thickness inhealthy children.To make a correct interpretation of ocT measurements,ocular magnificationeffect should be taken into account by clinicians or OCT manufacturers.展开更多
Arc-soft-toe bracket(ASTB), as a joint structure in the marine structure, is the hot spot with significant stress concentration, therefore, fatigue behavior of ASTBs is an important point of concern in their design. S...Arc-soft-toe bracket(ASTB), as a joint structure in the marine structure, is the hot spot with significant stress concentration, therefore, fatigue behavior of ASTBs is an important point of concern in their design. Since macroscopic geometric factors obviously influence the stress flaws in joints, the shapes and sizes of ASTBs should represent the stress distribution around cracks in the hot spots. In this paper, we introduce a geometric magnification factor for reflecting the macroscopic geometric effects of ASTB crack features and construct a 3D finite element model to simulate the distribution of stress intensity factor(SIF) at the crack endings. Sensitivity analyses with respect to the geometric ratio Ht/Lb, R/Lb, Lt/Lb are performed, and the relations between the geometric factor and these parameters are presented. A set of parametric equations with respect to the geometric magnification factor is obtained using a curve fitting technique. A nonlinear relationship exists between the SIF and the ratio of ASTB arm to toe length. When the ratio of ASTB arm to toe length reaches a marginal value, the SIF of crack at the ASTB toe is not influenced by ASTB geometric parameters. In addition, the arc shape of the ASTB slope edge can transform the stress flowing path, which significantly affects the SIF at the ASTB toe. A proper method to reduce stress concentration is setting a slope edge arc size equal to the ASTB arm length.展开更多
Vibration can be introduced in all mechanical fields in our life.Engineers try to avoid its negative effect leading in some cases to deformation in the machines.Many researches are dedicated to study the identificatio...Vibration can be introduced in all mechanical fields in our life.Engineers try to avoid its negative effect leading in some cases to deformation in the machines.Many researches are dedicated to study the identification of damping especially in multi degree of freedom systems with particular attention to the source of energy dissipation.They focus on developing new tools or methods which may be used in real problems to obtain accurate results about the amount(or value)and the location of energy dissipation in the structure.The aim of this paper is to present an original procedure aims to experimentally determine the modal damping ratio of a mechanical structure.The proposed procedure consists of extracting the Frequency Response Function of the vibrating system using the video magnification method and then calculate the modal damping ratio using the 3-dB method.These experimental measurements are carried out by giving an external force on a cantilever beam,then the modal damping ratios are extracted using motion magnification.The obtained results show a relative error less than 4.2% between the experimental measurements and the analytical calculation for the Frequency Response Function(FRF)curves.The novelty of the paper is to combine the video magnification technique and the 3dB method in a procedure that aims to experimentally measure the modal damping of a mechanical structure.The proposed procedure in this paper represents the damping identification as a simple and easy engineering application.展开更多
thermal magnification device is proposed by using effective thermal conductivity. Different fromtransformation optics method, the magnification design is realized analytically by enforcingequality of effective ther...thermal magnification device is proposed by using effective thermal conductivity. Different fromtransformation optics method, the magnification design is realized analytically by enforcingequality of effective thermal conductivity on the magnification device and the reference case inspecified domains. The validity of theoretical analysis is checked by numerical simulation results,which demonstrates the magnifying effects of the proposed design. The device only needsisotropic and homogeneous materials that are easy to obtain in nature. It is also shown that theobtained magnifying conditions are the same as those derived by separation of variables. But theproposed method proves more flexible for multilayered materials and simpler for non-sphericalobjects under non-uniform thermal fields. It can also be extended to other fields and applicationsgoverned by Laplace equation.展开更多
A high optical magnification three-dimensional imaging system is proposed using an optic microscope whose ocular （eyepiece） is retained and the structure of the transmission mode is not destroyed. The elemental imag...A high optical magnification three-dimensional imaging system is proposed using an optic microscope whose ocular （eyepiece） is retained and the structure of the transmission mode is not destroyed. The elemental image array is captured through the micro lens array. Due to the front diffuse transmission element, each micro lens sees a slightly different spatial perspective of the scene, and a different independent image is formed in each micro lens channel. Each micro lens channel is imaged by a Fourier lens and captured by a CCD. The design translating the stage in x or y provides no parallax. Compared with the conventional integral imaging of micro-objects, the optical magnification of micro-objects in the proposed system can enhanced remarkably. The principle of the enhancement of the image depth is explained in detail and the experimental results are presented.展开更多
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
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
文摘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.
文摘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.
文摘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.
文摘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.
基金Supported by an unrestricted grant to Dr. Ragunath by Olympus Keymed United Kingdom
文摘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.
基金a grant from the Research Grants Council othe Hong Kong Special Administrative Region,China(NoPolyU 5199/06E)by the National Natural ScienceFoundation of China(No.60472036,No.60431020,No60402036,No.60772069)the Natural Science Foundation of Beijing(No.4062006).
文摘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.
文摘AIM: To compare the yield of adenomas between narrow band imaging and white light when using high definition/magnification. METHODS: This prospective, non-randomized comparative study was performed at the endoscopy unit of veteran affairs medical center in Phoenix, Arizona. Consecutive patients undergoing first average risk colorectal cancer screening colonoscopy were selected. Two experienced gastroenterologists performed all the procedures that were blinded to each other's findings. Demographic details were recorded. Data are presented as mean ± SEM. Proportional data were compared using the χ2 test and means were compared using the Student's t test. Tandem colonoscopy was performed in a sequential and segmental fashion using one of 3 strategies: white light followed by narrow band imaging [Group A: white light(WL) → narrow band imaging(NBI)]; narrow band imaging followed by white light(Group B: NBI → WL) and, white light followed by white light(Group C: WL → WL). Detection rate of missed polyps and adenomas were evaluated in all three groups. RESULTS: Three hundred patients were studied(100 in each Group). Although the total time for the colonoscopy was similar in the 3 groups(23.8 ± 0.7, 22.2 ± 0.5 and 24.1 ± 0.7 min for Groups A, B and C, respectively), it reached statistical significance between Groups B and C(P < 0.05). The cecal intubation time in Groups B and C was longer than for Group A(6.5 ± 0.4 min and 6.5 ± 0.4 min vs 4.9 ± 0.3 min; P < 0.05). The withdrawal time for Groups A and C was longer than Group B(18.9 ± 0.7 min and 17.6 ± 0.6min vs 15.7 ± 0.4 min; P < 0.05). Overall miss rate for polyps and adenomas detected in three groups during the second look was 18% and 17%, respectively(P = NS). Detection rate for polyps and adenomas after first look with white light was similar irrespective of the light used during the second look(WL → WL: 13.7% for polyps, 12.6% for adenomas; WL → NBI: 14.2% for polyps, 11.3% for adenomas). Miss rate of polyps and adenomas however was significantly higher when NBI was used first(29.3% and 30.3%, respectively; P < 0.05). Most missed adenomas were ≤ 5 mm in size. There was only one advanced neoplasia(defined by size only) missed during the first look. CONCLUSION: Our data suggest that the tandem nature of the procedure rather than the optical techniques was associated with the detection of additional polyps' and adenomas.
文摘Endoscopy is an indispensible diagnostic and thera-peutic instrument for gastrointestinal diseases. Endo-cytoscopy and confocal endomicroscopy are two types of ultra high magnification endoscopy techniques.Standard endoscopy allows for 50 × magnification,whereas endocytoscopy can magnify up to 1400 × and confocal endomicroscopy can magnify up to 1000 ×.These methods open the realm of real time micros copicevaluation of the GI tract, including cellular and subcellular structures. Confocal endomicroscopy has the additional advantage of being able to visualize subsurface structures. The use of high magnification endoscopy inconjunction with standard endoscopy allows for a real-time microscopic assessment of areas with macroscopic abnormalities, providing "virtual biopsies" with valuable information about cellular and subcellular changes. Thiscan minimize the number of biopsies taken at the time of endoscopy. The use of this technology may assistin detecting premalignant or malignant changes at anearlier state, allowing for earlier intervention and treatment. High magnification endoscopy has shown promising results in clinical trials for Barrett's esophagus,esophageal adenocarcinoma, esophageal squamous cell cancer, gastric cancer, celiac disease, colorectalcancer, and inflammatory bowel disease. As the use of high magnification endoscopy techniques increases,the clinical applications will increase as well. Of the two systems, only confocal endomicroscopy is currently commercially available. Like all new technologies there will be an initial learning curve before operators become proficient in obtaining high quality images and discerning abnormal from normal pathology. Validatedcriteria for the diagnosis of the various gastrointestinal diseases will need to be developed for each method. Inthis review, the basic principles of both modalities are discussed, along with their clinical applic ability and limitations.
文摘Russell body gastritis(RBG) is an unusual type of chronic gastritis characterized by marked infiltration of Mott cells,which are plasma cells filled with spherical eosinophilic bodies referred to as Russell bodies.It was initially thought that Helicobacter pylori(H.pylori) infection was a major cause of RBG and that the infiltrating Mott cells were polyphenotypic;however,a number of cases of RBG without H.pylori infection or with monoclonal Mott cells have been reported.Thus,diagnostic difficulty exists in distinguishing RBG with monoclonal Mott cells from malignant lymphoma.Here,we report an unusual case of an 86-year-old-Japanese man with H.pylori-positive RBG.During the examination of melena,endoscopic evaluation confirmed a 13-mm whitish,flat lesion in the gastric antrum.Magnification endoscopy with narrowband imaging suggested that the lesion was most likely a poorly differentiated adenocarcinoma.Biopsy findings were consistent with chronic gastritis with many Mott cells with intranuclear inclusions referred to as Dutcher bodies.Endoscopic submucosal dissection confirmed the diagnosis of RBG with kappa-restricted monoclonal Mott cells.Malignant lymphoma was unlikely given the paucity of cytological atypia and Ki-67 immunoreactivity of monoclonal Mott cells.This is the first reported case of RBG with endoscopic diagnosis of malignant tumor and the presence of Dutcher bodies.
基金the National Natural Science Foundation of China(51225804,U1234204,51222803,51178418)for the financial supports
文摘The magnitude of dynamic load produced by high-speed trains depends on many factors,of which train speed is the most critical one.However,it is quite difficult to determine the effect of train speed on dynamic load using the theoretical methods due to the complexity of the interaction between vehicle and track-subgrade.Thus large-scale model test has gradually become an important approach for studying dynamic responses of ballastless track-subgrade of high-speed railway.In this study,a full-scale model of ballastless track-subgrade was constructed in accordance with the design and construction standards for Shanghai-Nanjing intercity high-speed railway line firstly.Then,the dynamic strain of slab and the dynamic earth pressure of subgrade were measured by conducting single wheel axle excitation test.In addition,the relationship between the dynamic load magnification factor（DLF） and the train speed was obtained.Finally,the DLF of track-subgrade under different train speeds was proposed,similar to that given by German Railway Standard.
基金Sociedade Portuguesa de Endoscopia Digestiva (Research Grant 2002)the European Society for Gastrointestinal Endoscopy
文摘AIM： To evaluate the use of web-based technologies to assess the learning curve and reassess reproducibility of a simplified version of a classification for gastric magnification chromoendoscopy （MC）. METHODS： As part of a multicenter trial, a hybrid approach was taken using a CD-ROM, with 20 films of MC lasting 5 s each and an ＂autorun＂ file triggering a local HTML frameset referenced to a remote questionnaire through an Internet connection. Three endoscopists were asked to prospectively and independently classify 10 of these films randomly selected with at least 3 d apart. The answers were centrally stored and returned to participants together with adequate feedback with the right answer. RESULTS： For classification in 3 groups, both intra- [Cohen＇s kappa （K） = 0.79-1.00 to 0.89-1.00] and inter-observer agreement increased from 1st （moderate） to 6th observation （k = 0.94）. Also, agreement with reference increased in the last observations （0.90, 1.00 and 1.00, for observers A, B and C, respectively）. Validity of 100% was obtained by all observers at their 4th observation. When a 4th （sub）group was considered, inter-observer agreement was almost perfect （K = 0.92） at 6th observation. The relation with reference clearly improved into K （0.93-1.00） and sensitivity （75%-100%） at their 6th observations. CONCLUSION： This MC classification seems to be easily explainable and learnable as shown by excellent intra- and inter-observer agreement, and improved agreement with reference. A web system such as the one used in this study may be useful for endoscopic or other image based diagnostic procedures with respect to definition, education and dissemination.
文摘A precise zoom magnification is important for semiconductor industry and biomedical research. A novel measurement method is demonstrated for optical zoom magnification measurement in this paper. The magnification is obtained by pattern correction between barcode image formed by optical zoom and reference image generated by an ideal optical model. Measurement accuracy which is better than 0.06% has been achieved for optical zoom magnification. Compared with traditional concept, the measurement results are only dependent on two line edges. The barcode correlation method can achieve higher accuracy and better robustness by using the information over the whole field of view.
基金Department of International Corporation of Yunnan Province and Tokyo University of Japan.
文摘The digital seismometers with high accuracy are installed at depths of -200 m, -100 m in borehole and on the surface in Dongchuan. By analysis of spectra ratio, the local events (with epicentral distances between 8.5 km and 95 km, magnitudes ML = 1.3-5.1) recorded are used to calculate site magnification factor at different depths (-100 m and surface) in Dongchuan. Comparing results with that at the depth of -200 m, the site magnification factors at three components of N-S, E-W and U-D corresponding to the depth of -100 m at 8 frequencies (f = 0.75, 1.0, 1.5, 2, 3, 4, 6, and 12 Hz) are 1.0-1.49 when 0.75 Hz- [less-than or equal to] f [less-than or equal to] 2 Hz and 0.47-0.99 when 2 Hz less than or equal f less than or equal 12 Hz. On the surface, site magnification factors at three components are all greater than 1, i.e. between 1.6 and 7.63. The correlation coefficients of site magnification factors for S wave and coda at the depth of -100 m and on surface are 0.82 and 0.81 when 0.75 Hz [less-than or equal to] f [less-than or equal to] 2 Hz, 0.47 and 0.45 when 2 Hz less than or equal f less than or equal 12 Hz, respectively.
文摘Purpose:The aim of this paper was to examine the distribution of macular,retinal nerve fiber layer(RNFL)thickness and optic disc parameters of myopic and hyperopic eyes in comparison withemmetropic control eyes and to investigate their variation according to axial length(AL)andspherical equivalent(SE)in healthy children.Methods:This study included 293 pairs of eyes of 293children(145 boys and 148 girks),ranging in age from 6 to 17 years,Subjects were dividedaccording to SE in control(emmetropia,99 children),myopia(100 children)and hyperopia(94children)groups and according to axial AL in 68 short(<22.00 mm,68),medium(from≥22.00 mmto 25.00 mm,189)and long eyes(>25.00 mm,36).Macular parameters,RNFL thickness and opticdisc morphology were assessed by the Cirrus^(TM) HD-OCT.AL was measured using the IOL-Mastersystem.Littmann's formula was used for calculating the corrected AL-related ocular magnification.Results Mean age(±SD)was 10.84±3.05 years;mean(±SD)SE was+0.14±0.51 D(range from8.75 to+8.25 D)and mean AL(±SD)was 23.12±1.49.Average RNFL thickness,averagemacular thickness and macular volume decreased as AL and myopia increased.No correlationsbetween AL/SE and optic disc parameters were found after correcting for magnification effect.Conclusions:AL and refractive error affect measurements of macular and RNFL thickness inhealthy children.To make a correct interpretation of ocT measurements,ocular magnificationeffect should be taken into account by clinicians or OCT manufacturers.
基金supported by the National Natural Science Foundation of China (NSFC) (Nos. 51490675 and 11572300)the Natural Science Foundation of Shandong Province (NSFSD) (No. ZR2015EM025)the Fundamental Research Fund for Central Universities (Ocean University of China)
文摘Arc-soft-toe bracket(ASTB), as a joint structure in the marine structure, is the hot spot with significant stress concentration, therefore, fatigue behavior of ASTBs is an important point of concern in their design. Since macroscopic geometric factors obviously influence the stress flaws in joints, the shapes and sizes of ASTBs should represent the stress distribution around cracks in the hot spots. In this paper, we introduce a geometric magnification factor for reflecting the macroscopic geometric effects of ASTB crack features and construct a 3D finite element model to simulate the distribution of stress intensity factor(SIF) at the crack endings. Sensitivity analyses with respect to the geometric ratio Ht/Lb, R/Lb, Lt/Lb are performed, and the relations between the geometric factor and these parameters are presented. A set of parametric equations with respect to the geometric magnification factor is obtained using a curve fitting technique. A nonlinear relationship exists between the SIF and the ratio of ASTB arm to toe length. When the ratio of ASTB arm to toe length reaches a marginal value, the SIF of crack at the ASTB toe is not influenced by ASTB geometric parameters. In addition, the arc shape of the ASTB slope edge can transform the stress flowing path, which significantly affects the SIF at the ASTB toe. A proper method to reduce stress concentration is setting a slope edge arc size equal to the ASTB arm length.
文摘Vibration can be introduced in all mechanical fields in our life.Engineers try to avoid its negative effect leading in some cases to deformation in the machines.Many researches are dedicated to study the identification of damping especially in multi degree of freedom systems with particular attention to the source of energy dissipation.They focus on developing new tools or methods which may be used in real problems to obtain accurate results about the amount(or value)and the location of energy dissipation in the structure.The aim of this paper is to present an original procedure aims to experimentally determine the modal damping ratio of a mechanical structure.The proposed procedure consists of extracting the Frequency Response Function of the vibrating system using the video magnification method and then calculate the modal damping ratio using the 3-dB method.These experimental measurements are carried out by giving an external force on a cantilever beam,then the modal damping ratios are extracted using motion magnification.The obtained results show a relative error less than 4.2% between the experimental measurements and the analytical calculation for the Frequency Response Function(FRF)curves.The novelty of the paper is to combine the video magnification technique and the 3dB method in a procedure that aims to experimentally measure the modal damping of a mechanical structure.The proposed procedure in this paper represents the damping identification as a simple and easy engineering application.
基金supported by the National Natural Science Foundation of China (11732002,11672089, 11325210, and 11421091)
文摘thermal magnification device is proposed by using effective thermal conductivity. Different fromtransformation optics method, the magnification design is realized analytically by enforcingequality of effective thermal conductivity on the magnification device and the reference case inspecified domains. The validity of theoretical analysis is checked by numerical simulation results,which demonstrates the magnifying effects of the proposed design. The device only needsisotropic and homogeneous materials that are easy to obtain in nature. It is also shown that theobtained magnifying conditions are the same as those derived by separation of variables. But theproposed method proves more flexible for multilayered materials and simpler for non-sphericalobjects under non-uniform thermal fields. It can also be extended to other fields and applicationsgoverned by Laplace equation.
基金Supported by the Scientific Research Fund Project of the Education Department of Shaanxi Province under Grant No 15JK1732the Natural Science Foundation of Shaanxi Province under Grant No2014JQ1044the Science Foundation of Northwest University under Grant No 12NW01
文摘A high optical magnification three-dimensional imaging system is proposed using an optic microscope whose ocular （eyepiece） is retained and the structure of the transmission mode is not destroyed. The elemental image array is captured through the micro lens array. Due to the front diffuse transmission element, each micro lens sees a slightly different spatial perspective of the scene, and a different independent image is formed in each micro lens channel. Each micro lens channel is imaged by a Fourier lens and captured by a CCD. The design translating the stage in x or y provides no parallax. Compared with the conventional integral imaging of micro-objects, the optical magnification of micro-objects in the proposed system can enhanced remarkably. The principle of the enhancement of the image depth is explained in detail and the experimental results are presented.
文摘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.
基金supported by the Key Research and Development Program of Jiangsu Province under Grant BE2022059-3,CTBC Bank through the Industry-Academia Cooperation Project,as well as by the Ministry of Science and Technology of Taiwan through Grants MOST-108-2218-E-002-055,MOST-109-2223-E-009-002-MY3,MOST-109-2218-E-009-025,and MOST431109-2218-E-002-015.
文摘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.
