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Heteronuclear intermolecular single-quantum coherences in liquid nuclear magnetic resonance 被引量:1
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作者 陈松 朱小钦 +1 位作者 蔡淑惠 陈忠 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第3期915-920,共6页
This paper analyses the heteronuclear Cosy Revamped by Asymmetric Z-gradient Echo Detection pulse sequence. General theoretical expressions of the pulse sequence with arbitrary flip angles were derived by using dipola... This paper analyses the heteronuclear Cosy Revamped by Asymmetric Z-gradient Echo Detection pulse sequence. General theoretical expressions of the pulse sequence with arbitrary flip angles were derived by using dipolar field treatment and signals originating from heteronuclear intermolecular single-quantum coherences (iSQCs) in highly-polarized two spin-1/2 systems were mainly discussed in order to find the optimal flip angles. The results show that signals from heteronuclear iSQCs decay slower than those from intermolecular double-quantum coherences or intermolecular zero-quantum coherences. Magical angle experiments validate that the signals are from heteronuclear iSQCs and insensitive to the imperfection of radio-frequency flip angles. All experimental observations are in excellent agreement with theoretical predictions. The quantum-mechanical treatment leads to similar predictions to the dipolar field treatment. 展开更多
关键词 nuclear magnetic resonance heteronuclear multiple-quantum coherences distant dipolar field highly-polarized system
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Electroencephalographic coherences during emotion identification task
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作者 Erzsebet Marosi Holczberger Jorge Bernal +4 位作者 Juan Silva Guillermina Yanez Mario Rodríguez Belen Prieto Vicente Guerrero 《World Journal of Neuroscience》 2012年第4期248-253,共6页
Coherence, a measure of spectral similarity, may estimate cortical coupling between two EEG signals as a function of frequency. The coherence between EEG signals from different brain areas depends on the structural co... Coherence, a measure of spectral similarity, may estimate cortical coupling between two EEG signals as a function of frequency. The coherence between EEG signals from different brain areas depends on the structural connection and functional coupling between two regions. The theory of hemispheric specialization proposes left hemisphere activation to positive emotions and right one to negative emotions. Other proposal is that right hemisphere activation occurs with emotional stimuli. In the present study EEG coherences were calculated during the presentation of the International Affective Pictures to 36 healthy male university students. The subjects’ task was to determine the valence of the stimuli. Base line recording were done with subjects observing the blank monitor. Our results showed higher coherences during the emotional condition. No differences between negative and positive emotions were obtained. Neutral pictures evoked the highest coherence values. These data suggest that coherences between functionally coupled brain areas do not reflect emotional recognition of the valence of stimuli, but they are internal indicators of different mental processes such as memory, mental effort and arousal. Our findings do not support the theory of hemispheric specialization, neither the theory of right hemisphere;rather they suggest a complex activation pattern that involves mostly frontal areas in connection with the entire cortex. 展开更多
关键词 EEG coherences Emotions of Positive and Negative Valence International Affective Pictures
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Giant Kerr nonlinearity induced by interacting quantum coherences from decays and incoherent pumping
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作者 白艳锋 杨文星 +1 位作者 韩定安 喻小强 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第11期266-270,共5页
A scheme for generating the giant enhancement of the Kerr nonlinearity in a four-level system with the quantum coherences from the decays and the incoherent pumping is proposed. Compared with that generated in a gener... A scheme for generating the giant enhancement of the Kerr nonlinearity in a four-level system with the quantum coherences from the decays and the incoherent pumping is proposed. Compared with that generated in a general four- level system, the Kerr nonlinearity can be enhanced by several orders of magnitude with vanishing linear absorption. By using the numerical results, we show that the remarkable enhancement should be attributed to the interaction of the quantum coherences from the decays and the incoherent pumping. 展开更多
关键词 Kerr nonlinearity coherence induced by incoherent pumping spontaneously generatedcoherence
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Multiple Quantum Coherences(MQ) NMR and Entanglement Dynamics in the Mixed-Three-Spin XXX Heisenberg Model with Single-Ion Anisotropy
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作者 Hamid Arian Zad 《Communications in Theoretical Physics》 SCIE CAS CSCD 2016年第12期629-637,共9页
We analytically investigate Multiple Quantum(MQ) NMR dynamics in a mixed-three-spin(1/2,1,1/2)system with XXX Heisenberg model at the front of an external homogeneous magnetic field B. A single-ion anisotropy property... We analytically investigate Multiple Quantum(MQ) NMR dynamics in a mixed-three-spin(1/2,1,1/2)system with XXX Heisenberg model at the front of an external homogeneous magnetic field B. A single-ion anisotropy property ζ is considered for the spin-1. The intensities dependence of MQ NMR coherences on their orders(zeroth and second orders) for two pairs of spins(1,1/2) and(1/2,1/2) of the favorite tripartite system are obtained. It is also investigated dynamics of the pairwise quantum entanglement for the bipartite(sub)systems(1,1/2) and(1/2,1/2)permanently coupled by, respectively, coupling constants J_1 and J_2, by means of concurrence and fidelity. Then, some straightforward comparisons are done between these quantities and the intensities of MQ NMR coherences and ultimately some interesting results are reported. We also show that the time evolution of MQ coherences based on the reduced density matrix of the pair spins(1,1/2) is closely connected with the dynamics of the pairwise entanglement. Finally, we prove that one can introduce MQ coherence of the zeroth order corresponds to the pair spins(1,1/2) as an entanglement witness at some special time intervals. 展开更多
关键词 multiple quantum coherence single-ion anisotropy concurrence entanglement witness
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高分辨率纵波时差实时提取方法研究与应用
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作者 郭尚静 苏远大 +2 位作者 张利伟 赵龙 凌子晨 《测井技术》 2026年第1期172-180,共9页
声波测井是油气勘探中的重要技术之一,纵波时差可用于岩性划分、力学参数计算、优化钻完井方案等。在声波速度测井现场作业中,纵波时差曲线的实时提取普遍采用首波到时门槛法,该方法在薄互层地层与非常规储层的应用中,存在纵波时差提取... 声波测井是油气勘探中的重要技术之一,纵波时差可用于岩性划分、力学参数计算、优化钻完井方案等。在声波速度测井现场作业中,纵波时差曲线的实时提取普遍采用首波到时门槛法,该方法在薄互层地层与非常规储层的应用中,存在纵波时差提取精度低、纵向分辨率不足的问题,难以满足薄互层精细识别与评价的工程需求。本文采用多源相似叠加法构建具有相同跨度的子阵列,结合慢度—时间相关法(Slowness—Time Coherence,STC),实现不同分辨率纵波时差提取,在此基础上,针对岩性变化剧烈地层中固定时窗提取不稳定的问题,提出了一种动态时窗方法,使开窗位置能够随地层声学特征变化自适应调整,最终形成了高分辨率纵波时差实时提取方法,并将此方法集成至中海油田服务股份有限公司的增强型成像测井系统(Enhanced Logging Imaging System,ELIS)中,在山西、新疆和墨西哥等不同地质条件区块开展了现场应用验证。研究结果表明:①多源相似叠加与常规STC方法能够有效提高纵波时差提取的纵向分辨率,针对0.5 ft^(*)薄层,厚度识别准确率可达91.3%;②动态时窗显著提高了岩性变化剧烈地层中纵波时差提取的稳定性,同时增强了时差提取结果与自然伽马曲线之间的相关性;③高分辨率纵波时差实时提取方法的现场应用验证了该方法实时提取的纵波时差曲线在岩性剧烈变化地层中的鲁棒性与普适性,以及所得纵波时差曲线的准确性和高分辨率特征。结论认为,本文提出的高分辨率纵波时差实时提取方法能够有效获取薄层声学响应特征,为薄互层及非常规储层的精细识别与实时评价提供了一种高效、可靠的技术手段。 展开更多
关键词 高分辨率纵波时差 多源相似叠加 动态时窗 实时提取 慢度—时间相关法(Slowness—Time Coherence STC) 声波速度测井 子阵列跨度组合 薄互层评价
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Broadband high-coherence supercontinuum in Al_(0.24)Ga_(0.76)As photonic crystal fibers
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作者 XIA Yong-tao HOU Shang-lin +4 位作者 FENG Yun-long XIE Cai-jian LEI Jing-li WU Gang YAN Zu-yong 《中国光学(中英文)》 北大核心 2026年第1期164-178,共15页
An alternative elliptical and circle air-hole-assisted Al_(0.24)Ga_(0.76)As photonic crystal fiber(PCF)was proposed for generating broadband high-coherence mid-infrared supercontinuum,and the dispersion,effect-ive mod... An alternative elliptical and circle air-hole-assisted Al_(0.24)Ga_(0.76)As photonic crystal fiber(PCF)was proposed for generating broadband high-coherence mid-infrared supercontinuum,and the dispersion,effect-ive mode area and nonlinear coefficient were investigated by using finite element method(FEM),the evolu-tion of optical pulses propagating along the fiber was simulated,and the supercontinuum and the coherence were analyzed and evaluated under different pumping conditions.The results show that a supercontinuum spectrum with a spectral width of 4.852μm can be obtained in the proposed fiber with d_(1)/Λof 0.125,d_(2)/Λof 0.583 and the zero-dispersion wavelength of 3.228μm by pumping with a Gaussian pulse with a peak power of 800 W and a full width at half maximum(FWHM)of 20 fs at wavelength of 3.3μm.When the fiber is pumped by the pulse with the peak power of 2000 W,the FWHM of 80 fs at the wavelength of 4.0μm in the in the anomalous dispersion region,the modulation instability is obviously suppressed,and the high-coher-ence supercontinuum spectrum spanning from 1.1μm to 8.99μm is observed.A part of the pulse energy is transferred to the anomalous dispersion region when pumped at the wavelength of 2.8μm in the normal dis-persion region and a broadband high-coherence supercontinuum spectrum extending from 0.8μm to 9.8μm is generated in the 10 mm proposed fiber.This paper introduces elliptical air holes in the Al_(0.24)Ga_(0.76)As photonic crystal fiber,which enhances flexibility for tailoring the performance of supercontinuum,ultimately achieving the broadest supercontinuum spectrum with the shortest fiber length to date. 展开更多
关键词 SUPERCONTINUUM photonic crystal fiber COHERENCE Al_(0.24)Ga_(0.76)As
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Therapeutic approaches to diabetic macular edema assessed using optical coherence tomography and optical coherence tomography angiography
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作者 Parisa Alsadat Dadkhah Hamed Taheri +14 位作者 Masoud Noroozi Asma Rasouli Zahra Sheikh Saba Imanparvar Saeed Zivari Lashkajani Nahid Samadi Javad Nadem Behzadmehr Amirian Goharsharieh Alishiri Ata Akhtari Kohnehshahri Arshia Shafiei Amirreza Heydarlou Reza Khademi Anahita Rahmati Niloofar Deravi 《International Journal of Ophthalmology(English edition)》 2026年第1期160-174,共15页
Overt and harmful diabetes mellitus(DM)has detrimental effects on individuals and,by extension,the community.Among the microvascular DM complications is diabetic retinopathy(DR).DR may cause irreversible vision deteri... Overt and harmful diabetes mellitus(DM)has detrimental effects on individuals and,by extension,the community.Among the microvascular DM complications is diabetic retinopathy(DR).DR may cause irreversible vision deterioration in cases of poor blood glucose regulation.Changes in vascular permeability are key trigger points for diabetic macular edema(DME),a condition characterized by the accumulation of fluid in the macula.The development of vascular endothelial growth factor(VEGF)pathway inhibitors has provided a pathogenesis-based treatment approach for DME.Optical coherence tomography(OCT)provides highresolution imaging of the anatomy,including the aging of DME and its structural damage,in distinct morphologic subtypes of macular edema,thereby supporting the assessment of macular edema treatment.The availability of repeated OCT monitoring provides clinical reassurance through the treatment.OCT angiography(OCTA)provides retinal blood flow maps with high spatial resolution.The ability promotes an understanding of disease pathogenesis and facilitates the implementation of new therapeutic methods.This review compares the potential of OCT and OCTA in the diagnosis and treatment of DME,as well as their respective therapeutic applications. 展开更多
关键词 diabetic macular edema optical coherence tomography optical coherence tomography angiography vascular endothelial growth factor
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Quantitative correlation between stress variation and charge signals of loaded coal and its implication for dynamic fracturing of surrounding rock
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作者 Jinguo Lyu Zhanpeng Xue +3 位作者 Yishan Pan Lianpeng Dai Zhi Tang Xuebin Wang 《International Journal of Mining Science and Technology》 2026年第2期313-331,共19页
To address the key scientific challenge of monitoring the dynamic fracturing of surrounding rock in deep roadways,this study systematically investigates the quantitative relationship between stress and charge signals ... To address the key scientific challenge of monitoring the dynamic fracturing of surrounding rock in deep roadways,this study systematically investigates the quantitative relationship between stress and charge signals during coal mass loading.By integrating innovative analytical approaches,introducing quantitative evaluation indices,and developing a charge–stress inversion model,and incorporating underground monitoring practices,significant progress has been achieved in elucidating the correlation between stress variations and charge signals throughout the entire coal mass fracturing process.First,in the field of stress–charge correlation analysis,empirical mode decomposition(EMD)was combined with wavelet coherence analysis for the first time,enabling the removal of slow-varying stress trends while retaining high-frequency fluctuations.This approach allowed for the quantitative characterization of the evolution of coherence between stress variations and charge fluctuations across multiple time scales.Second,coherence skewness and the proportion of high-coherence intervals were innovatively introduced to examine the influence of time scale selection on correlation results.On this basis,a criterion for determining the near-optimal observation scale of charge signals was proposed,providing a quantitative reference for time scale selection in similar signal analyses.Finally,by correlating charge signals with coal damage factors and stress states,a charge-based damage evolution equation was established to achieve effective stress inversion.Combined with in situ monitoring of stress and charge in roadway surrounding rock,this approach revealed the correlation characteristics of stress and charge intensity responses during the dynamic fracturing process.The results indicate,first,that charge signals are not significantly correlated with the absolute stress level of coal but are directly associated with stress variations following coal damage and failure,with the amplitude of charge fluctuations increasing alongside stress fluctuations.Second,coherence between stress and charge signals varies markedly across time scales,with excessively small or large scales leading to distortion,and the scale corresponding to the peak proportion of intervals with coherence>0.8 was identified as the near-optimal observation scale.Third,charge signals can effectively characterize coal damage factors,and the established damage evolution equation can effectively invert stress variation trends.Fourth,in underground roadways,zones of dynamic fracturing in surrounding rock are commonly located in areas where stress concentration overlaps with regions of high charge intensity,further confirming the strong consistency between charge and stress variations.These findings improve the theoretical framework of charge signal responses in loaded coal and provide a scientific basis for precise“stress-charge”monitoring of dynamic disasters,offering practical potential for engineering applications. 展开更多
关键词 CHARGE Stress Coherence coefficient Time scale Dynamic fracturing
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Energy dynamics and circuit implementation for a neuron with a memcapacitive membrane
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作者 Binchi WANG Yitong GUO +1 位作者 Guodong REN Jun MA 《ENGINEERING Information Technology & Electronic Engineering》 2026年第1期59-70,共12页
The output voltages for the capacitive elements of a neural circuit model can be mapped into dimensionless capacitive variables,which present firing patterns similar to the membrane potentials detected in biological n... The output voltages for the capacitive elements of a neural circuit model can be mapped into dimensionless capacitive variables,which present firing patterns similar to the membrane potentials detected in biological neurons.The inclusion of a memcapacitor also en‐ables consideration of membrane deformation effects,enhancing the model’s capacity to simulate neuronal behavior across varying physio‐logical and environmental conditions.In this study,a capacitor and a memcapacitor are connected through a linear resistor in parallel with other electric components in different branch circuits composed of an inductor and a nonlinear resistor.The electrical activities in a neuron with a double-layer membrane and two capacitive variables are discussed in detail after converting the nonlinear equations for the neural circuit into a theoretical neuron model.A dimensionless neuron model and its corresponding energy function are derived.The field energy function for the neural circuit is converted into an equivalent Hamilton energy function and further validated via the Helmholtz theorem.Furthermore,the average value of energy serves as an indicator for predicting stochastic resonance,as supported by analyzing the distribu‐tion of the coefficient of variation.The neuronal firing patterns are shown to be energy-dependent.An adaptive control strategy is proposed to regulate mode transitions in electrical activities of the neuron.An analog equivalent circuit is constructed to experimentally verify the nu‐merical results,thereby supporting the reliability of the proposed neuron model. 展开更多
关键词 Neural circuit Neuron model Hamilton energy Memcapacitor Coherence resonance
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Evaluation of tooth physiological characteristics based on PS-OCT
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作者 Songwen Xu Weike Wang +3 位作者 Di Yang Xiaoyi Zhao Hao Liu Yanmei Liang 《Journal of Innovative Optical Health Sciences》 2026年第2期89-101,共13页
Accurate and early evaluation of dental physiological characteristics is essential for effective disease detection and management.Polarization-sensitive optical coherence tomography(PS-OCT)is a noninvasive high-resolu... Accurate and early evaluation of dental physiological characteristics is essential for effective disease detection and management.Polarization-sensitive optical coherence tomography(PS-OCT)is a noninvasive high-resolution imaging technique that can obtain tooth structure and physiological features through intensity,retardation and degree of polarization uniformity(DOPU)images.In this study,we use the information provided by the PS-OCT system,especially the retardation information,to assess the physiological characteristics of teeth.In addition,we introduce a novel parameter—the rate of change of the retardation value(R)—to evaluate the magnitude of birefringence of enamel,which serves as an indicator of enamel health and mineralization.The results demonstrate that PS-OCT not only provides structural detail comparable to microcomputed tomography(microCT),but also yields additional physiological characteristics insights through polarization-based contrast.These findings highlight the strong potential of PS-OCT for early diagnosis,functional evaluation and personalized monitoring in dental care. 展开更多
关键词 Polarization-sensitive optical coherence tomography RETARDATION TOOTH physiological characteristics
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A bibliometric and visualized analysis of choriocapillaris from 2013 to 2023
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作者 Pu-Ying Wei Xi-Zhe Wang Jin-Ming Han 《International Journal of Ophthalmology(English edition)》 2026年第3期600-611,共12页
AIM:To assess the current research status and emerging trends of the choriocapillaris(CC)by bibliometric analysis.METHODS:Publications spanning from January 2013 to May 2023 were retrieved on June 27th,2023,using the ... AIM:To assess the current research status and emerging trends of the choriocapillaris(CC)by bibliometric analysis.METHODS:Publications spanning from January 2013 to May 2023 were retrieved on June 27th,2023,using the Web of Science Core Collection.Bibliometric and visualized analyses were performed employing the bibliometrix,CiteSpace and VOSviewer.RESULTS:A total of 1563 papers met the inclusion criteria,and a publication growth trend was observed.The United States was the leading country in the CC field.Retina and Investigative Ophthalmology&Visual Science stood out as highly impactful and prolific journals.Research topics in the CC field encompassed choroidal neovascularization,choroidal thickness,central serous chorioretinopathy,agerelated macular degeneration,myopia,choroidal vascularity index,and diabetic retinopathy,based on the co-citation analysis.The keyword“high myopia”experienced a burst lasting until 2023.CONCLUSION:In the past decade,research in the field of CC has flourished due to recent advancements in choroidal imaging;with focus shifting towards elucidating its role in various diseases.This will provide novel insights into managing chorioretinal diseases and vision-preserving interventions. 展开更多
关键词 BIBLIOMETRIC CHORIOCAPILLARIS age-related macular degeneration optical coherence tomography angiography
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Intravitreal Conbercept injection for different types of macular edema in retinal vein occlusion
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作者 Xue Jiarui Qian Xiaoping +1 位作者 Dong Jinghong Wu Changfan 《国际眼科杂志》 2026年第3期361-367,共7页
AIM:To analyze the effect of conbercept treatment on different types of macular edema secondary to retinal vein occlusion(RVO-ME)using optical coherence tomography(OCT)images.METHODS:This retrospective study included ... AIM:To analyze the effect of conbercept treatment on different types of macular edema secondary to retinal vein occlusion(RVO-ME)using optical coherence tomography(OCT)images.METHODS:This retrospective study included patients who first received conbercept injections for RVO-ME at Yijishan Hospital of Wannan Medical College from December 1,2017,to March 31,2022.Data on disease duration,age,hypertension,OCT images,central macular thickness(CMT),and best-corrected visual acuity(BCVA)were collected before and at 4-6 wk after treatment.Patients were divided into 4 groups according to different types of macular edema:cystoid macular edema(CME),sponge-like diffuse retinal thickening(SDRT),serous retinal detachment(SRD),and mixed type(FULL).Changes in CMT and visual acuity before and after treatment were compared among the groups to analyze differences in the effect of conbercept treatment on different ME types,and the effect of baseline CMT and visual acuity on post-treatment visual acuity.RESULTS:Totally 139 patients(139 eyes)were classified as having macular edema,including 62 males(44.6%)and 77 females(55.4%),with a mean age of 58.9±10.9 years,and they were divided into 4 groups based on different types of macular edema,including 54 cases(54 eyes)(mean age 59.6±11.1 years)in the CME group,23 cases(23 eyes;mean age 56.6±10.2 years)in the SDRT group,22 cases(22 eyes;mean age 57.8±12.0 years)in the SDR group,and 40 cases(40 eyes;mean age 60.0±10.7 years)in the FULL group.There were no significant differences in the duration of disease or age between groups(P>0.05).There was a significant difference in preoperative CMT between groups(P=0.01,one-way ANOVA),with the CMT in the FULL group being significantly greater than that in the SDRT group(P=0.03).There were no significant differences in pre-treatment visual acuity between the four groups(P=0.26).After conbercept treatment,the macular central recess thickness was reduced and visual acuity was improved in all four groups,among which the CMT in the CME and FULL groups was reduced significantly compared with the other two groups(P<0.05),and the visual acuity in the CME and SRD groups was improved significantly compared with the other two groups(P<0.05).Postoperative visual acuity was negatively correlated with preoperative CMT(P=0.044)and positively correlated with preoperative visual acuity(P<0.01).CONCLUSION:The efficacy of intravitreal conbercept in the treatment of RVO and macular edema may be related to the type of edema observed on OCT images,in which the efficacy is best in patients with CME but poor in patients with SDRT. 展开更多
关键词 retinal vein occlusion macular edema conbercept coherent optical tomography
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Optical coherence tomography for surgical demarcation of GI tumor margins for accelerated decision-making during the surgical resection of tumors
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作者 Mohamed Nijas Veluthedath Anuradha Sekaran +3 位作者 Manjoosha R Yerrapragada Pradeep Rebala Duvvuru Nageshwar Reddy Renu John 《Journal of Innovative Optical Health Sciences》 2026年第2期116-128,共13页
Gastric cancer,including stomach tumors,poses significant health challenges due to late-stage diagnosis and limited early detection methods.Accurate imaging and precise tumor margin demarcation are critical for effect... Gastric cancer,including stomach tumors,poses significant health challenges due to late-stage diagnosis and limited early detection methods.Accurate imaging and precise tumor margin demarcation are critical for effective treatment planning and improved patient outcomes.Conventional imaging techniques,such as endoscopy and histopathology,provide valuable diagnostic information but cannot offer real-time assessment.We aim to explore the application of optical coherence tomography(OCT),combined with statistical and machine learning methods,for rapid tumor margin demarcation in gastrointestinal(GI)cancer tissues in exvivo.GI tumor specimens from 17 patients were imaged intraoperatively with OCT.Quantitative features were extracted from the images,and statistical and machine learning analyses were applied to distinguish tissue types.Subsequent histopathological evaluation was used as the reference standard for validation.The combination of OCT imaging and data-driven analysis enables clear differentiation between healthy,marginal and tumor tissues in near real-time.The KNN model achieved the highest classification accuracy(0.921±0.040),with SVM(0.906±0.038)and Extra Trees(0.901±0.034)also demonstrating robust performance in discriminating tissue margins.OCT findings demonstrate strong agreement with histopathology.Integrated with statistical and machine learning techniques,OCT enables rapid assessment of GI tumor margins.This approach provides quantitative objectivity and real-time feedback,closely approximating histopathological analysis and supporting improved surgical decision-making. 展开更多
关键词 Optical coherence tomography gastrointestinal tumor tumor demarcation optical biopsy
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Evaluation of retina and choroid via OCT in anti-DFS70/LEDGF positive healthy individuals
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作者 Ata Baytaroğlu Suzan Doğruya I.Merve Uçar Baytaroğlu 《International Journal of Ophthalmology(English edition)》 2026年第3期532-538,共7页
AIM:To investigate the association between anti-DFS70 antibody positivity and ocular parameters,specifically,the choroidal vascularity index(CVI)and other optical coherence tomography(OCT)metrics,in a healthy populati... AIM:To investigate the association between anti-DFS70 antibody positivity and ocular parameters,specifically,the choroidal vascularity index(CVI)and other optical coherence tomography(OCT)metrics,in a healthy population.METHODS:This age-and sex-matched case-control study enrolled 84 healthy individuals with positive anti-DFS70 antibody findings and 84 healthy negative controls.All participants underwent detailed ophthalmological examinations,including biometry and OCT imaging.Anti-DFS70 positivity was determined by indirect immunofluorescence and scored semi-quantitatively(1+to 3+).CVI was calculated from OCT images using a standardized protocol with Image J software.Statistical analyses,including Student’s t-test,Mann-Whitney U test,Spearman correlation,and logistic regression,were used to compare groups and identify predictive factors.RESULTS:The individuals who tested positive and negative for anti-DFS70 included in the study were matched for age(median age=47y)and sex(F:M=7:1).CVI was significantly lower in the anti-DFS70-positive group compared to the negative group.A higher anti-DFS70 antibody titer was significantly associated with decreased subfoveal and nasal choroidal thickness(P=0.016 and P=0.014,respectively).In univariate regression analysis,CVI was the only significant predictor of anti-DFS70 positivity[odds ratio(OR)=0.02,P=0.025].Multivariate analysis revealed a positive correlation between macular thinning outside the subfoveal area and anti-DFS70 status(P<0.05).CONCLUSION:Our study demonstrates a novel association between anti-DFS70 antibody positivity and reduced choroidal vascularity in healthy individuals.These findings suggest that anti-DFS70 antibodies may be associated with subtle choroidal vascular changes detectable by OCT,even in asymptomatic individuals.Further longitudinal research is warranted to clarify the underlying mechanisms and long-term clinical significance of these ocular changes. 展开更多
关键词 anti-DFS70 antibodies choroidal vascularity index optical coherence tomography AUTOIMMUNITY
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Retinal layers thickness and retinal vascular parameters in patients with multiple sclerosis
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作者 Mehdi Moghaddasi Mahsa Sardarinia +3 位作者 Mostafa Soltansanjari Ahmad Vafajoo Nafise Mohebi Simin Zare 《国际眼科杂志》 2026年第3期368-374,共7页
AIM:To investigate the changes of retinal vascular parameters and retinal layer thickness in patients with multiple sclerosis(MS).METHODS:This single-centered case-control study was performed on a MS group of 42 patie... AIM:To investigate the changes of retinal vascular parameters and retinal layer thickness in patients with multiple sclerosis(MS).METHODS:This single-centered case-control study was performed on a MS group of 42 patients diagnosed with MS and a control group of 43 healthy hospital staff matched in terms of age and sex at Iran University,department of neurology and ophthalmology from March 2020 to March 2021.The ophthalmic parameters of each patient were recorded,and optical coherence tomography was used to evaluate the retinal thickness in the layers.RESULTS:This study enrolled a total of 85 participants,with a mean age of 40.44±11.52 years,including 61 females(72%).The control group consisted of 43 individuals with a mean age of 39.49±11.07 years,while the MS group comprised 42 participants with a mean age of 41.40±12.01 years.The mean disease duration in the MS group was 8.45±6.04 a.The thickness of the ganglion cell layer in the right eye was significantly lower in the MS group compared to the control group(P=0.034).In addition,except for the left nasal sector(P=0.106),the mean peripapillary neurofibrillation in all examined sectors were significantly lower in the MS group than in the control group(P<0.05).The average vessel density in both the deep and superficial capillary plexuses across all regions of both eyes was lower in the MS group than in the control group,with all comparisons for the superficial capillary plexus showing statistical significance(P<0.05 for all except the left nasal sector).CONCLUSION:The thickness of the retina of patients with MS is significantly reduced.Therefore,optical coherence tomography results can be used as a reliable tool to evaluate disease progression and prognosis in MS patients. 展开更多
关键词 multiple sclerosis optical coherence tomography RETINA retinal vascular disorder retinal layer thickness
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Agreement between swept-source OCT-based and Scheimpflug-based optical biometers in myopic children
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作者 Ying-Yan Qin Zhao-Tian Zhang +4 位作者 Shu-Wen Xing Shi-Ya Lin Bai-Zhou Chen Liang-Ping Liu Yao Ni 《International Journal of Ophthalmology(English edition)》 2026年第2期339-345,共7页
AIM:To evaluate the agreement of axial length(AL),anterior chamber parameters,and total cornea power obtained by swept-source optical coherence tomography(SS-OCT)-based and Scheimpflug-based optical biometers in myopi... AIM:To evaluate the agreement of axial length(AL),anterior chamber parameters,and total cornea power obtained by swept-source optical coherence tomography(SS-OCT)-based and Scheimpflug-based optical biometers in myopic children.METHODS:AL,steep keratometry(K),flat K,posterior corneal keratometry(PK),total keratometry(TK),anterior chamber depth(ACD),horizontal corneal diameter(CD),and central corneal thickness(CCT)were obtained using IOL Master 700 and Pentacam AXL.The agreement between the devices was evaluated using intraclass correlation coefficients(ICC),Bland-Altman plots,and astigmatism vector analysis.RESULTS:Totally 175 myopic children(48.5%male)with a mean age of 10.29±2.14y were enrolled.The ICC and Bland-Altman plots indicated a satisfactory agreement for AL,ACD,and CCT.The mean difference in CD of-0.31±0.30 mm was considered clinically significant(>0.2 mm).Additionally,measurements of K and TK obtained from the IOL Master 700 showed good agreement.Nevertheless,there were clinically significant differences observed in PK,simulated keratometry(simK),total cornea power,and astigmatism(at least 10%of the cases with a difference of>10 degrees in meridian)between the two devices.CONCLUSION:The study findings demonstrate a significant difference in K,PK,astigmatism,and CD,indicating that the two optical biometers cannot be considered interchangeable.Therefore,it is recommended to utilize one kind device for follow-up examinations in myopic children. 展开更多
关键词 MYOPIA axial length total cornea power optical biometers swept-source optical coherence tomography
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Controllable phase-dependent optical switch in an atom-cavity system
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作者 Xu-Yang Li Yuan-Feng Lu +2 位作者 Ya-Jie Wu Ning Li Miao-Di Guo 《Chinese Physics B》 2026年第2期408-414,共7页
Coherent perfect absorption(CPA)and coherent perfect transmission(CPT)are two extreme states arising from the manipulation of optical fields.Generally,CPA and CPT occur under different input-field phases.Therefore,we ... Coherent perfect absorption(CPA)and coherent perfect transmission(CPT)are two extreme states arising from the manipulation of optical fields.Generally,CPA and CPT occur under different input-field phases.Therefore,we propose a scheme to realize an all-optical switch based on phase-dependent CPA–CPT conversion.In our proposal,the CPT state and the CPA state are treated as the on state and the off state,respectively.Consequently,the efficiency of this all-optical switch can reach the maximum value of 1.With the introduction of an incoherent pump field,the CPA state can be achieved under a weaker input probe field or can be converted into a CPT state.The results show that the optical switch can operate with weaker fields and can be further optimized by the application of an incoherent field. 展开更多
关键词 coherent perfect absorption CAVITY-QED optical switching
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Ranibizumab on optic disc perfusion in central retinal vein occlusion
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作者 Xuan Li Xiao-Feng Hao +2 位作者 Li-Ke Xie Jin-Hua Luo Meng-Jiao Zhang 《International Journal of Ophthalmology(English edition)》 2026年第1期77-82,共6页
AIM:To evaluate the therapeutic effects of ranibizumab on optic disc and macular microvascular perfusion in central retinal vein occlusion(CRVO)with macular edema(ME).METHODS:Optical coherence tomography angiology(OCT... AIM:To evaluate the therapeutic effects of ranibizumab on optic disc and macular microvascular perfusion in central retinal vein occlusion(CRVO)with macular edema(ME).METHODS:Optical coherence tomography angiology(OCTA)parameters,including optic disc vessel density(VD;including whole-disc VD,intra-disc VD,and peripapillary VD),superficial/deep capillary plexus(SCP/DCP)VD,and central macular thickness(CMT)were analyzed.Additional assessments included best-corrected visual acuity(BCVA)via Early Treatment Diabetic Retinopathy Study(ETDRS)chart and hemorheological profiling.CRVO patients received monthly intravitreal ranibizumab injections for three consecutive months.Pre-and post-treatment parameters were statistically compared.RESULTS:The study comprised 60 CRVO-ME patients(28 males;32 females),aged 50-78y(mean 63.3±7.6y)and 60 age-/sex-matched healthy controls.As compared with participants exhibiting normal funduscopic findings,CRVO patients demonstrated significantly elevated levels of low-shear-rate whole blood viscosity(LSR-WBV),high-shearrate whole blood viscosity(HSR-WBV),and aggregation index(AI,all P<0.05).In CRVO-affected eyes,vertical cupto-disc(C/D)ratio and optic cup volume were significantly smaller,whereas retinal nerve fiber layer(RNFL)thickness was significantly greater,compared to both unaffected contralateral eyes and normal control eyes(all P<0.05).Following treatment,VD of the entire optic disc(P<0.05),intra-disc VD(P<0.05),and peripapillary VD(P<0.05)all increased significantly relative to baseline.CMT decreased significantly(P<0.05),whereas macular SCP-VD and macular DCP-VD showed non-significant slight reductions(P>0.05).At baseline,BCVA of CRVO eyes correlated with whole-disc VD(r=-0.276,P=0.033),intra-disc VD(r=-0.342,P=0.009),and peripapillary VD(r=-0.335,P=0.007),with intra-disc VD demonstrating the strongest association.Besides,BCVA improvement,after the treatment,correlated positively with whole-disc VD(r=0.342,P=0.008)and intradisc VD(r=0.396,P=0.002).CONCLUSION:Optic disc blood perfusion is more closely associated with visual acuity than macular perfusion,suggesting intra-disc VD may serve as a potential biomarker for monitoring visual acuity changes in CRVO.Multiple ranibizumab injections significantly improve optic disc perfusion but may have exerted detrimental effects on the macula.CRVO patients shows higher hemorheological parameters than those with normal fundi.Reduced vertical C/D ratio and optic cup volume may be linked to CRVO incidence,potentially acting as susceptibility factors. 展开更多
关键词 central retinal vein occlusion macular edema optic disc RANIBIZUMAB optical coherence tomography angiology
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Mitigating emittance and longitudinal profile degradation of non-ideal bunches caused by CSR in multi-bend deflecting beamlines
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作者 Xiu-Ji Chen Si Chen +1 位作者 Hai-Xiao Deng Dong Wang 《Nuclear Science and Techniques》 2026年第3期50-64,共15页
Preserving beam quality during the transport of high-brightness electron bunches is crucial for advanced accelerator applications,such as particle colliders,free-electron lasers,and recirculating linacs.However,cohere... Preserving beam quality during the transport of high-brightness electron bunches is crucial for advanced accelerator applications,such as particle colliders,free-electron lasers,and recirculating linacs.However,coherent synchrotron radiation(CSR)significantly degrades beam quality when electron bunches pass through multi-bend isochronous beamlines,particularly for short bunches with non-ideal longitudinal profiles.Although several methods have been proposed to mitigate CSR effects,most rely on small-angle approximations or are limited to idealized bunch profiles.In this study,we present two improved methods for designing isochronous triple-bend achromat(TBA)beamlines that effectively mitigate CSR-induced emittance growth and longitudinal profile distortion without relying on small-angle approximations.The first method,an enhanced integral optimization approach,simplifies numerical optimization and can accurately handle larger deflection angles,making it suitable for practical applications that require flexible lattice configurations.The second method,an optimized I-matrix approach,completely cancels steady-state and transient CSR kicks through specific matrix constraints and higher-order dispersion optimization,enabling effective CSR suppression even with very large deflection angles.Systematic simulations demonstrate that both methods achieve excellent preservation of transverse emittance and longitudinal profiles. 展开更多
关键词 Lattice design Coherent synchrotron radiation Horizontal emittance
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C-SegNet:a practical approach for automated diabetic macular edema segmentation in optical coherence tomography images
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作者 Zhi-Yuan Guan Ge Deng +6 位作者 Shi-Long Shi Zhen Tang Xian-Kun Dong Qiu-Yi Li Shu-Jing Shen Yong-Ling He Xue-Jun Qiu 《Biomedical Engineering Communications》 2026年第2期15-22,共8页
Background:Diabetic macular edema is a prevalent retinal condition and a leading cause of visual impairment among diabetic patients’Early detection of affected areas is beneficial for effective diagnosis and treatmen... Background:Diabetic macular edema is a prevalent retinal condition and a leading cause of visual impairment among diabetic patients’Early detection of affected areas is beneficial for effective diagnosis and treatment.Traditionally,diagnosis relies on optical coherence tomography imaging technology interpreted by ophthalmologists.However,this manual image interpretation is often slow and subjective.Therefore,developing automated segmentation for macular edema images is essential to enhance to improve the diagnosis efficiency and accuracy.Methods:In order to improve clinical diagnostic efficiency and accuracy,we proposed a SegNet network structure integrated with a convolutional block attention module(CBAM).This network introduces a multi-scale input module,the CBAM attention mechanism,and jump connection.The multi-scale input module enhances the network’s perceptual capabilities,while the lightweight CBAM effectively fuses relevant features across channels and spatial dimensions,allowing for better learning of varying information levels.Results:Experimental results demonstrate that the proposed network achieves an IoU of 80.127%and an accuracy of 99.162%.Compared to the traditional segmentation network,this model has fewer parameters,faster training and testing speed,and superior performance on semantic segmentation tasks,indicating its highly practical applicability.Conclusion:The C-SegNet proposed in this study enables accurate segmentation of Diabetic macular edema lesion images,which facilitates quicker diagnosis for healthcare professionals. 展开更多
关键词 multi-scale input diabetic macular edema image segmentation optical coherence tomography
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