期刊文献+
共找到283,419篇文章
< 1 2 250 >
每页显示 20 50 100
A virtual model of the retina based on histological data as a tool for evaluation of the visual fields
1
作者 Francisco-Javier Carreras Ángel V.Delgado José.L.García-Serrano 《Annals of Eye Science》 2017年第1期113-126,共14页
Background:To settle the fundamentals of a numerical procedure that relates retinal ganglion-cell density and threshold sensitivity in the visual field.The sensitivity of a generated retina and visual pathways to virt... Background:To settle the fundamentals of a numerical procedure that relates retinal ganglion-cell density and threshold sensitivity in the visual field.The sensitivity of a generated retina and visual pathways to virtual stimuli are simulated,and the conditions required to reproduce glaucoma-type defects both in the optic-nerve head(ONH)and visual fields are explored.Methods:A definition of selected structural elements of the optic pathways is a requisite to a translation of clinical knowledge to computer programs for visual field exploration.The program is able to generate a database of normalized visual fields.The relationship between the number of extant receptive fields and threshold sensitivity is plotted for background sensitivity and corresponding automated perimetry.A solution in two planes to the 3D distribution of axons in the ONH is proposed.Visual fields with induced damage in the optic disc are comparable in pattern and quantity to glaucomatous records.Results:The two-level simulation of the ONH facilitates the analysis of optic-cup/retinal defects.We can generate the virtual optic pathways tailored to the age and morphology of the patient’s eye,and it is possible to reproduce glaucomatous damage by“reverse engineering”engineering.The virtual cortical model renders a quantitative relationship between visual defect and neural damage.Conclusions:A two-level computing of the retina/optic nerve facilitates the analysis of neuroretinal defects and can be incorporated to automatic perimeters to facilitate visual field analysis. 展开更多
关键词 Computer modeling early optic pathways neuroretinal defects threshold sensitivity visual fields
下载PDF
Heterogeneous Image Knowledge Driven Visual Perception 被引量:1
2
作者 Lan Yan Wenbo Zheng Fei-Yue Wang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第1期255-257,共3页
Dear Editor,This letter is concerned with visual perception closely related to heterogeneous images.Facing the huge challenge brought by different image modalities,we propose a visual perception framework based on het... Dear Editor,This letter is concerned with visual perception closely related to heterogeneous images.Facing the huge challenge brought by different image modalities,we propose a visual perception framework based on heterogeneous image knowledge,i.e.,the domain knowledge associated with specific vision tasks,to better address the corresponding visual perception problems. 展开更多
关键词 visual visual KNOWLEDGE
下载PDF
Predictive visual field outcomes after optic chiasm decompressive surgery by retinal vessels parameters using optical coherence tomography angiography
3
作者 Wen-Juan Yu Jin Xiao +3 位作者 Guang-Xin Wang Chang Jiang Wei Zha Rong-Feng Liao 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第2期365-373,共9页
AIM:To evaluate the predictive value of superficial retinal capillary plexus(SRCP)and radial peripapillary capillary(RPC)for visual field recovery after optic cross decompression and compare them with peripapillary ne... AIM:To evaluate the predictive value of superficial retinal capillary plexus(SRCP)and radial peripapillary capillary(RPC)for visual field recovery after optic cross decompression and compare them with peripapillary nerve fiber layer(pRNFL)and ganglion cell complex(GCC).METHODS:This prospective longitudinal observational study included patients with chiasmal compression due to sellar region mass scheduled for decompressive surgery.Generalized estimating equations were used to compare retinal vessel density and retinal layer thickness preand post-operatively and with healthy controls.Logistic regression models were used to assess the relationship between preoperative GCC,pRNFL,SRCP,and RPC parameters and visual field recovery after surgery.RESULTS:The study included 43 eyes of 24 patients and 48 eyes of 24 healthy controls.Preoperative RPC and SRCP vessel density and pRNFL and GCC thickness were lower than healthy controls and higher than postoperative values.The best predictive GCC and pRNFL models were based on the superior GCC[area under the curve(AUC)=0.866]and the tempo-inferior pRNFL(AUC=0.824),and the best predictive SRCP and RPC models were based on the nasal SRCP(AUC=0.718)and tempo-inferior RPC(AUC=0.825).There was no statistical difference in the predictive value of the superior GCC,tempo-inferior pRNFL,and tempo-inferior RPC(all P>0.05).CONCLUSION:Compression of the optic chiasm by tumors in the saddle area can reduce retinal thickness and blood perfusion.This reduction persists despite the recovery of the visual field after decompression surgery.GCC,pRNFL,and RPC can be used as sensitive predictors of visual field recovery after decompression surgery. 展开更多
关键词 sellar region mass retinal vessels optic chiasm optical coherence tomography angiography visual field decompressive surgery
原文传递
Values of macular ganglion cell-inner plexiform layer and 10-2 visual field measurements in detecting and evaluating glaucoma
4
作者 Hai-Jian Hu Ping Li +7 位作者 Bin Tong Yu-Lian Pang Hong-Dou Luo Fei-Fei Wang Chan Xiong Yu-Lin Yu Hai He Xu Zhang 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第5期852-860,共9页
AIM:To assess the performance of macular ganglion cell-inner plexiform layer thickness(mGCIPLT)and 10-2 visual field(VF)parameters in detecting early glaucoma and evaluating the severity of advanced glaucoma.METHODS:T... AIM:To assess the performance of macular ganglion cell-inner plexiform layer thickness(mGCIPLT)and 10-2 visual field(VF)parameters in detecting early glaucoma and evaluating the severity of advanced glaucoma.METHODS:Totally 127 eyes from 89 participants(36 eyes of 19 healthy participants,45 eyes of 31 early glaucoma patients and 46 eyes of 39 advanced glaucoma patients)were included.The relationships between the optical coherence tomography(OCT)-derived parameters and VF sensitivity were determined.Patients with early glaucoma were divided into eyes with or without central 10°of the VF damages(CVFDs),and the diagnostic performances of OCT-derived parameters were assessed.RESULTS:In early glaucoma,the mGCIPLT was significantly correlated with 10-2 VF pattern standard deviation(PSD;with average mGCIPLT:β=-0.046,95%CI,-0.067 to-0.024,P<0.001).In advanced glaucoma,the mGCIPLT was related to the 24-2 VF mean deviation(MD;with average mGCIPLT:β=0.397,95%CI,0.199 to 0.595,P<0.001),10-2 VF MD(with average mGCIPLT:β=0.762,95%CI,0.485 to 1.038,P<0.001)and 24-2 VF PSD(with average mGCIPLT:β=0.244,95%CI,0.124 to 0.364,P<0.001).Except for the minimum and superotemporal mGCIPLT,the decrease of mGCIPLT in early glaucomatous eyes with CVFDs was more severe than that of early glaucomatous eyes without CVFDs.The area under the curve(AUC)of the average mGCIPLT(AUC=0.949,95%CI,0.868 to 0.982)was greater than that of the average circumpapillary retinal nerve fiber layer thickness(cpRNFLT;AUC=0.827,95%CI,0.674 to 0.918)and rim area(AUC=0.799,95%CI,0.610 to 0.907)in early glaucomatous eyes with CVFDs versus normal eyes.CONCLUSION:The 10-2 VF and mGCIPLT parameters are complementary to 24-2 VF,cpRNFLT and ONH parameters,especially in detecting early glaucoma with CVFDs and evaluating the severity of advanced glaucoma in group level. 展开更多
关键词 10-2 visual field ganglion cell-inner plexiform layer retinal nerve fiber layer thickness GLAUCOMA
原文传递
Visual Modflow在和田县农业经济新区地下水资源评价中的应用
5
作者 杭辉 苏前龙 《陕西水利》 2024年第3期27-30,共4页
为全面了解地下水系统受各种激励因素影响后的水动力场和地下水量变化规律,以及为当地地下水资源开发与利用提供科学的指导意见,本次在和田县农业经济新区地下水资源评价中采用可视化标准软件Visnal Modflow实现地下水资源的模拟与预报... 为全面了解地下水系统受各种激励因素影响后的水动力场和地下水量变化规律,以及为当地地下水资源开发与利用提供科学的指导意见,本次在和田县农业经济新区地下水资源评价中采用可视化标准软件Visnal Modflow实现地下水资源的模拟与预报,通过构建三维非稳定流数值模型,使用迭代方法求解,并根据设计开采量对地下水水位变动做出预测,再基于建模预测结果,结合经济新区地下水资源量确定合理的地下水开采量。 展开更多
关键词 visual Modflow 数值模拟 概念模型
下载PDF
Bioactive material promotes longdistance regeneration of optic nerve to restore visual functions
6
作者 Kai Liu 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第1期160-160,共1页
Visual system is vital to human beings.Unfortunately,the optic nerve lacks the ability to regenerate after injury.Therefo re,long-distance regeneration of the optic nerve is a major unsolved medical problem in the wor... Visual system is vital to human beings.Unfortunately,the optic nerve lacks the ability to regenerate after injury.Therefo re,long-distance regeneration of the optic nerve is a major unsolved medical problem in the world(Laha et al.,2017).Recently,Li and So groups' study showed that the bioactive material(ciliary neurotrophic factor[CNTF]-chitosan) could promote long-distance regeneration of the completely transected optic nerve in adult rats and partially restored the visual functions(Liu et al.,2023).This study sheds light on the clinical potential for repairing the severely injured optic nerve. 展开更多
关键词 visual visual FUNCTIONS
下载PDF
MULTIPLE INTERSECTIONS OF SPACE-TIME ANISOTROPIC GAUSSIAN FIELDS
7
作者 陈振龙 苑伟杰 《Acta Mathematica Scientia》 SCIE CSCD 2024年第1期275-294,共20页
Let X={X(t)∈R^(d),t∈R^(N)}be a centered space-time anisotropic Gaussian field with indices H=(H_(1),…,H_(N))∈(0,1)~N,where the components X_(i)(i=1,…,d)of X are independent,and the canonical metric√(E(X_(i)(t)-X... Let X={X(t)∈R^(d),t∈R^(N)}be a centered space-time anisotropic Gaussian field with indices H=(H_(1),…,H_(N))∈(0,1)~N,where the components X_(i)(i=1,…,d)of X are independent,and the canonical metric√(E(X_(i)(t)-X_(i)(s))^(2))^(1/2)(i=1,…,d)is commensurate with■for s=(s_(1),…,s_(N)),t=(t_(1),…,t_(N))∈R~N,α_(i)∈(0,1],and with the continuous functionγ(·)satisfying certain conditions.First,the upper and lower bounds of the hitting probabilities of X can be derived from the corresponding generalized Hausdorff measure and capacity,which are based on the kernel functions depending explicitly onγ(·).Furthermore,the multiple intersections of the sample paths of two independent centered space-time anisotropic Gaussian fields with different distributions are considered.Our results extend the corresponding results for anisotropic Gaussian fields to a large class of space-time anisotropic Gaussian fields. 展开更多
关键词 anisotropic Gaussian field multiple intersections Hausdorff measure capacity
下载PDF
Dynamic SLAM Visual Odometry Based on Instance Segmentation:A Comprehensive Review
8
作者 Jiansheng Peng Qing Yang +3 位作者 Dunhua Chen Chengjun Yang Yong Xu Yong Qin 《Computers, Materials & Continua》 SCIE EI 2024年第1期167-196,共30页
Dynamic Simultaneous Localization and Mapping(SLAM)in visual scenes is currently a major research area in fields such as robot navigation and autonomous driving.However,in the face of complex real-world envi-ronments,... Dynamic Simultaneous Localization and Mapping(SLAM)in visual scenes is currently a major research area in fields such as robot navigation and autonomous driving.However,in the face of complex real-world envi-ronments,current dynamic SLAM systems struggle to achieve precise localization and map construction.With the advancement of deep learning,there has been increasing interest in the development of deep learning-based dynamic SLAM visual odometry in recent years,and more researchers are turning to deep learning techniques to address the challenges of dynamic SLAM.Compared to dynamic SLAM systems based on deep learning methods such as object detection and semantic segmentation,dynamic SLAM systems based on instance segmentation can not only detect dynamic objects in the scene but also distinguish different instances of the same type of object,thereby reducing the impact of dynamic objects on the SLAM system’s positioning.This article not only introduces traditional dynamic SLAM systems based on mathematical models but also provides a comprehensive analysis of existing instance segmentation algorithms and dynamic SLAM systems based on instance segmentation,comparing and summarizing their advantages and disadvantages.Through comparisons on datasets,it is found that instance segmentation-based methods have significant advantages in accuracy and robustness in dynamic environments.However,the real-time performance of instance segmentation algorithms hinders the widespread application of dynamic SLAM systems.In recent years,the rapid development of single-stage instance segmentationmethods has brought hope for the widespread application of dynamic SLAM systems based on instance segmentation.Finally,possible future research directions and improvementmeasures are discussed for reference by relevant professionals. 展开更多
关键词 Dynamic SLAM instance segmentation visual odometry
下载PDF
Classification of congenital cataracts based on multidimensional phenotypes and its association with visual outcomes
9
作者 Yuan Tan Ying-Shi Zou +8 位作者 Ying-Lin Yu Le-Yi Hu Ting Zhang Hui Chen Ling Jin Duo-Ru Lin Yi-Zhi Liu Hao-Tian Lin Zhen-Zhen Liu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第3期473-479,共7页
●AIM:To establish a classification for congenital cataracts that can facilitate individualized treatment and help identify individuals with a high likelihood of different visual outcomes.●METHODS:Consecutive patient... ●AIM:To establish a classification for congenital cataracts that can facilitate individualized treatment and help identify individuals with a high likelihood of different visual outcomes.●METHODS:Consecutive patients diagnosed with congenital cataracts and undergoing surgery between January 2005 and November 2021 were recruited.Data on visual outcomes and the phenotypic characteristics of ocular biometry and the anterior and posterior segments were extracted from the patients’medical records.A hierarchical cluster analysis was performed.The main outcome measure was the identification of distinct clusters of eyes with congenital cataracts.●RESULTS:A total of 164 children(299 eyes)were divided into two clusters based on their ocular features.Cluster 1(96 eyes)had a shorter axial length(mean±SD,19.44±1.68 mm),a low prevalence of macular abnormalities(1.04%),and no retinal abnormalities or posterior cataracts.Cluster 2(203 eyes)had a greater axial length(mean±SD,20.42±2.10 mm)and a higher prevalence of macular abnormalities(8.37%),retinal abnormalities(98.52%),and posterior cataracts(4.93%).Compared with the eyes in Cluster 2(57.14%),those in Cluster 1(71.88%)had a 2.2 times higher chance of good best-corrected visual acuity[<0.7 logMAR;OR(95%CI),2.20(1.25–3.81);P=0.006].●CONCLUSION:This retrospective study categorizes congenital cataracts into two distinct clusters,each associated with a different likelihood of visual outcomes.This innovative classification may enable the personalization and prioritization of early interventions for patients who may gain the greatest benefit,thereby making strides toward precision medicine in the field of congenital cataracts. 展开更多
关键词 CLASSIFICATION congenital cataract PHENOTYPE visual acuity cluster analysis
原文传递
Accumulation of Heavy Metals in Maga-Pouss Rice Fields (Far-North Region, Cameroon) and Transfer to Rice Grains
10
作者 Diane Madomguia Gilbert Bello Basokdou +3 位作者 Kalieu W. Appoline Isabelle Patrice Kuitekam Dongo Edouard Nya Serge Hubert Zebaze Togouet 《Agricultural Sciences》 2024年第3期311-326,共16页
Monitoring of heavy metals contamination of agricultural products and their transfer and bioaccumulation in crops like rice has become a hot topic worldwide over the last two decades. The present study was carried out... Monitoring of heavy metals contamination of agricultural products and their transfer and bioaccumulation in crops like rice has become a hot topic worldwide over the last two decades. The present study was carried out to determine the accumulation of heavy metals in rice fields and their transfer to rice grains. Soil, irrigation water and rice grains samples were gathered in Maga-Pouss, Far-North, Cameroon. Concentrations of six heavy metals (lead, cadmium, zinc, copper, iron and mercury) were evaluated by Atomic Absorption Spectrophotometer (AAS). Mercury was not detected in this study. Average concentrations of metals were in this order (in mg/kg): Fe (188.60 ± 97.06) > Pb (63.63 ± 7.11) > Cd (2.59 ± 0.29) > Zn (1.10 ± 1.05) > Cu (0.80 ± 0.73) in water and Pb (105.50 ± 31.11) > Fe (105.50 ± 31.11) > Cu (45.93 ± 14.39) > Zn (22.52 ± 6.40) > Cd (3.15 ± 0.49) in soil. Water in Maga-Pouss rice fields appears to be more harmful than the soil, notably for lead, cadmium and copper. In rice grains, heavy metals were found in this order (mg/kg): Fe (188.01 ± 82.62) > Cu (27.20 ± 0.00) > Zn (23.61 ± 12.42) > Pb (19.50 ± 19.91) > Cd (2.02 ± 1.05). The mean bioconcentration factor (BCF) of metals from soil to rice grains was in the following order: Fe (2.60) > Zn (1.05) > Cd (0.64) > Cu (0.59) > Pb (0.18). From water to rice grains, the order is: Cu (37.26) > Zn (22.49) > Cd (6.97) > Pb (2.74) > Fe (1.94). Rice field pH and electrical conductivity favored the uptake of lead, copper and cadmium by rice grains. The findings of this study will be good documentation for risk assessment, and decision-making by environmental managers in this region. 展开更多
关键词 Heavy Metals Rice Field Bioconcenration Factor Maga-Pouss ACCUMULATION
下载PDF
Utility of real-time 3D visualization system in the early stage of phacoemulsification training
11
作者 Zhe Xu Dan Chen +4 位作者 Jing-Wei Xu Yi-Xuan Feng Ce Shi Li Zhang Wen Xu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第3期577-582,共6页
●AIM:To determine the teaching effects of a real-time three dimensional(3D)visualization system in the operating room for early-stage phacoemulsification training.●METHODS:A total of 10 ophthalmology residents of th... ●AIM:To determine the teaching effects of a real-time three dimensional(3D)visualization system in the operating room for early-stage phacoemulsification training.●METHODS:A total of 10 ophthalmology residents of the first-year postgraduate were included.All the residents were novices to cataract surgery.Real-time cataract surgical observations were performed using a custom-built 3D visualization system.The training lasted 4wk(32h)in all.A modified International Council of Ophthalmology’s Ophthalmology Surgical Competency Assessment Rubric(ICO-OSCAR)containing 4 specific steps of cataract surgery was applied.The self-assessment(self)and expert-assessment(expert)were performed through the microsurgical attempts in the wet lab for each participant.●RESULTS:Compared with pre-training assessments(self 3.2±0.8,expert 2.5±0.6),the overall mean scores of posttraining(self 5.2±0.4,expert 4.7±0.6)were significantly improved after real-time observation training of 3D visualization system(P<0.05).Scores of 4 surgical items were significantly improved both self and expert assessment after training(P<0.05).●CONCLUSION:The 3D observation training provides novice ophthalmic residents with a better understanding of intraocular microsurgical techniques.It is a useful tool to improve teaching efficiency of surgical education. 展开更多
关键词 3D visualization system phacoemulsification training wet lab
原文传递
基于Visual Components的套筒类零件柔性制造单元的应用研究
12
作者 潘文宏 《煤矿机械》 2024年第5期188-191,共4页
为实现多品种中、小批量零件的智能化加工,以套筒类零件加工为研究对象,通过对零件工艺的分析,为满足单元加工、搬运、翻转等功能需求,对数控机床和工业机器人进行选型,实现柔性制造单元的设计。利用Visual Components软件进行单元搭建... 为实现多品种中、小批量零件的智能化加工,以套筒类零件加工为研究对象,通过对零件工艺的分析,为满足单元加工、搬运、翻转等功能需求,对数控机床和工业机器人进行选型,实现柔性制造单元的设计。利用Visual Components软件进行单元搭建、仿真优化反馈以提高真实产线运行效率。利用Profinet实现制造单元真实搭建,完成单元安装调试。套筒类零件柔性制造单元的设计为生产线设计提供了新思路。 展开更多
关键词 套筒类零件 柔性制造单元 visual Components PROFINET
原文传递
Prevalence of visual impairment and estimation of refractive errors among school children in Kakamega,Kenya
13
作者 Isabel Signes-Soler Alfred Ragot +2 位作者 Sheilah Nangena Andrew Wekesa Raúl Montalbán Llamusí 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第5期932-939,共8页
AIM:To investigate the prevalence of visual impairment(VI)and provide an estimation of uncorrected refractive errors in school-aged children,conducted by optometry students as a community service.METHODS:The study was... AIM:To investigate the prevalence of visual impairment(VI)and provide an estimation of uncorrected refractive errors in school-aged children,conducted by optometry students as a community service.METHODS:The study was cross-sectional.Totally 3343 participants were included in the study.The initial examination involved assessing the uncorrected distance visual acuity(UDVA)and visual acuity(VA)while using a+2.00 D lens.The inclusion criteria for a subsequent comprehensive cycloplegic eye examination,performed by an optometrist,were as follows:a UDVA<0.6 decimal(0.20 logMAR)and/or a VA with+2.00 D≥0.8 decimal(0.96 logMAR).RESULTS:The sample had a mean age of 10.92±2.13y(range 4 to 17y),and 51.3%of the children were female(n=1715).The majority of the children(89.7%)fell within the age range of 8 to 14y.Among the ethnic groups,the highest representation was from the Luhya group(60.6%)followed by Luo(20.4%).Mean logMAR UDVA choosing the best eye for each student was 0.29±0.17(range 1.70 to 0.22).Out of the total,246 participants(7.4%)had a full eye examination.The estimated prevalence of myopia(defined as spherical equivalent≤-0.5 D)was found to be 1.45%of the total sample.While around 0.18%of the total sample had hyperopia value exceeding+1.75 D.Refractive astigmatism(cil<-0.75 D)was found in 0.21%(7/3343)of the children.The VI prevalence was 1.26%of the total sample.Among our cases of VI,76.2%could be attributed to uncorrected refractive error.Amblyopia was detected in 0.66%(22/3343)of the screened children.There was no statistically significant correlation observed between age or gender and refractive values.CONCLUSION:The primary cause of VI is determined to be uncorrected refractive errors,with myopia being the most prevalent refractive error observed.These findings underscore the significance of early identification and correction of refractive errors in school-aged children as a means to alleviate the impact of VI. 展开更多
关键词 visual impairment refractive errors MYOPIA AMBLYOPIA sustainable development goals
原文传递
Effect of applied electric fields on supralinear dendritic integration of interneuron
14
作者 樊亚琴 魏熙乐 +1 位作者 卢梅丽 伊国胜 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期84-95,共12页
Evidences show that electric fields(EFs)induced by the magnetic stimulation could modulates brain activities by regulating the excitability of GABAergic interneuron.However,it is still unclear how and why the EF-induc... Evidences show that electric fields(EFs)induced by the magnetic stimulation could modulates brain activities by regulating the excitability of GABAergic interneuron.However,it is still unclear how and why the EF-induced polarization affects the interneuron response as the interneuron receives NMDA synaptic inputs.Considering the key role of NMDA receptor-mediated supralinear dendritic integration in neuronal computations,we suppose that the applied EFs could functionally modulate interneurons’response via regulating dendritic integration.At first,we build a simplified multi-dendritic circuit model with inhomogeneous extracellular potentials,which characterizes the relationship among EF-induced spatial polarizations,dendritic integration,and somatic output.By performing model-based singular perturbation analysis,it is found that the equilibrium point of fast subsystem can be used to asymptotically depict the subthreshold input–output(sI/O)relationship of dendritic integration.It predicted that EF-induced strong depolarizations on the distal dendrites reduce the dendritic saturation output by reducing driving force of synaptic input,and it shifts the steep change of sI/O curve left by reducing stimulation threshold of triggering NMDA spike.Also,the EF modulation prefers the global dendritic integration with asymmetric scatter distribution of NMDA synapses.Furthermore,we identify the respective contribution of EF-regulated dendritic integration and EF-induced somatic polarization to an action potential generation and find that they have an antagonistic effect on AP generation due to the varied NMDA spike threshold under EF stimulation. 展开更多
关键词 GABAergic interneuron electrical field supralinear dendritic integration action potential generation
原文传递
The cardiovascular system at high altitude:A bibliometric and visualization analysis
15
作者 Mao-Lin Zhao Zhong-Jie Lu +6 位作者 Li Yang Sheng Ding Feng Gao Yuan-Zhang Liu Xue-Lin Yang Xia Li Si-Yi He 《World Journal of Cardiology》 2024年第4期199-214,共16页
BACKGROUND When exposed to high-altitude environments,the cardiovascular system undergoes various changes,the performance and mechanisms of which remain controversial.AIM To summarize the latest research advancements ... BACKGROUND When exposed to high-altitude environments,the cardiovascular system undergoes various changes,the performance and mechanisms of which remain controversial.AIM To summarize the latest research advancements and hot research points in the cardiovascular system at high altitude by conducting a bibliometric and visualization analysis.METHODS The literature was systematically retrieved and filtered using the Web of Science Core Collection of Science Citation Index Expanded.A visualization analysis of the identified publications was conducted employing CiteSpace and VOSviewer.RESULTS A total of 1674 publications were included in the study,with an observed annual increase in the number of publications spanning from 1990 to 2022.The United States of America emerged as the predominant contributor,while Universidad Peruana Cayetano Heredia stood out as the institution with the highest publication output.Notably,Jean-Paul Richalet demonstrated the highest productivity among researchers focusing on the cardiovascular system at high altitude.Furthermore,Peter Bärtsch emerged as the author with the highest number of cited articles.Keyword analysis identified hypoxia,exercise,acclimatization,acute and chronic mountain sickness,pulmonary hypertension,metabolism,and echocardiography as the primary research hot research points and emerging directions in the study of the cardiovascular system at high altitude.CONCLUSION Over the past 32 years,research on the cardiovascular system in high-altitude regions has been steadily increasing.Future research in this field may focus on areas such as hypoxia adaptation,metabolism,and cardiopulmonary exercise.Strengthening interdisciplinary and multi-team collaborations will facilitate further exploration of the pathophysiological mechanisms underlying cardiovascular changes in high-altitude environments and provide a theoretical basis for standardized disease diagnosis and treatment. 展开更多
关键词 Cardiovascular system High altitude HYPOXIA Bibliometric analysis visualIZATION
下载PDF
Enhancing visual security: An image encryption scheme based on parallel compressive sensing and edge detection embedding
16
作者 王一铭 黄树锋 +2 位作者 陈煌 杨健 蔡述庭 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期287-302,共16页
A novel image encryption scheme based on parallel compressive sensing and edge detection embedding technology is proposed to improve visual security. Firstly, the plain image is sparsely represented using the discrete... A novel image encryption scheme based on parallel compressive sensing and edge detection embedding technology is proposed to improve visual security. Firstly, the plain image is sparsely represented using the discrete wavelet transform.Then, the coefficient matrix is scrambled and compressed to obtain a size-reduced image using the Fisher–Yates shuffle and parallel compressive sensing. Subsequently, to increase the security of the proposed algorithm, the compressed image is re-encrypted through permutation and diffusion to obtain a noise-like secret image. Finally, an adaptive embedding method based on edge detection for different carrier images is proposed to generate a visually meaningful cipher image. To improve the plaintext sensitivity of the algorithm, the counter mode is combined with the hash function to generate keys for chaotic systems. Additionally, an effective permutation method is designed to scramble the pixels of the compressed image in the re-encryption stage. The simulation results and analyses demonstrate that the proposed algorithm performs well in terms of visual security and decryption quality. 展开更多
关键词 visual security image encryption parallel compressive sensing edge detection embedding
原文传递
Fluorescent Double Network Hydrogels with Ionic Responsiveness and High Mechanical Properties for Visual Detection
17
作者 郑湾 LIU Lerong +5 位作者 Lü Hanlin WANG Yuhang LI Feihu ZHANG Yixuan 陈艳军 WANG Yifeng 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第2期487-496,共10页
We developed a fluorescent double network hydrogel with ionic responsiveness and high mechanical properties for visual detection.The nanocomposite hydrogel of laponite and polyacrylamide serves as the first network,wh... We developed a fluorescent double network hydrogel with ionic responsiveness and high mechanical properties for visual detection.The nanocomposite hydrogel of laponite and polyacrylamide serves as the first network,while the ionic cross-linked hydrogel of terbium ions and sodium alginate serves as the second network.The double-network structure,the introduction of nanoparticles and the reversible ionic crosslinked interactions confer high mechanical properties to the hydrogel.Terbium ions are not only used as the ionic cross-linked points,but also used as green emitters to endow hydrogels with fluorescent properties.On the basis of the “antenna effect” of terbium ions and the ion exchange interaction,the fluorescence of the hydrogels can make selective responses to various ions(such as organic acid radical ions,transition metal ions) in aqueous solutions,which enables a convenient strategy for visual detection toward ions.Consequently,the fluorescent double network hydrogel fabricated in this study is promising for use in the field of visual sensor detection. 展开更多
关键词 visual detection ionic responsiveness fluorescent hydrogels double network hydrogels mechanical property
原文传递
Dual-Fields Rotational Total Skin Electron Therapy: Investigation and Implementation
18
作者 M. Ming Xu Iris Rusu Richard P. Garza 《International Journal of Medical Physics, Clinical Engineering and Radiation Oncology》 2024年第1期1-15,共15页
Purpose: To present a protocol of a dual-field rotational (DFR) total skin electron therapy (TSET) and to provide an assessment of clinical implementation, dosimetry properties, and skin dose evaluation. Methods and M... Purpose: To present a protocol of a dual-field rotational (DFR) total skin electron therapy (TSET) and to provide an assessment of clinical implementation, dosimetry properties, and skin dose evaluation. Methods and Materials: The DFR-TSET combined the Stanford 6-field and McGill rotational methods. Dual 6 MeV electron beams in high dose total skin electron mode were used for DFR-TSET on a commercial linac. Beam profiles and dosimetric properties were measured using solid phantoms. The dose rate at expanded source-to-surface distance (SSD) was a combination of static rate and rotational rate. In vivo dosimetry of patient skin was performed on patients’ skin using film, metal oxide semiconductor field-effect transistors (MOSFET), and optically stimulated luminescent dosimeters (OSLD). Results: Dual field rotational total skin electron therapy exhibited good (≤±10%) uniformity in the beam profiles in the vertical direction at an extended SSD of 332 cm with a gantry angulation of ±20˚ deviated from the horizontal direction. In-vivo measurements confirmed acceptable uniformity of the patients’ total body surfaces and revealed anatomically self-blocked or shielded areas where underdosing occurred. Conclusions: The clinical implementation of DFR-TSET effectively utilizes the special mode on a linac. This technique provides short beam-on times, uniform dose distribution, large treatment field, and reduced dose of x-ray contamination to the patients. In-vivo measurements indicate satisfactory delivery and dose uniformity of the prescribed dose. Electron boost fields are recommended at normal SSDs to address underdosed areas. 展开更多
关键词 Total Skin Electron Therapy Stanford 6 Field McGill Rotation Therapy In-Vivo Dosimetry
下载PDF
Suppression of stimulated Brillouin and Raman scatterings using an alternating frequency laser and transverse magnetic fields
19
作者 程瑞锦 李晓旬 +11 位作者 王清 刘德基 黄卓明 吕帅宇 周远志 张舒童 李雪铭 陈祖杰 王强 刘占军 曹莉华 郑春阳 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期545-553,共9页
A novel scheme to suppress both stimulated Brillouin scattering(SBS) and stimulated Raman scattering(SRS) by combining an alternating frequency(AF) laser and a transverse magnetic field is proposed. The AF laser allow... A novel scheme to suppress both stimulated Brillouin scattering(SBS) and stimulated Raman scattering(SRS) by combining an alternating frequency(AF) laser and a transverse magnetic field is proposed. The AF laser allows the laser frequency to change discretely and alternately over time. The suppression of SBS is significant as long as the AF difference is greater than the linear growth rate of SBS or the alternating time of the laser frequency is shorter than the linear growth time of SBS. However, the AF laser proves ineffective in suppressing SRS, which usually has a much higher linear growth rate than SBS. To remedy that, a transverse magnetic field is included to suppress the SRS instability. The electrons trapped in the electron plasma waves(EPWs) of SRS can be accelerated by the surfatron mechanism in a transverse magnetic field and eventually detrapped. While continuously extracting energy from EPWs, the EPWs are dissipated and the kinetic inflation of SRS is suppressed. The one-dimensional particle-in-cell simulation results show that both SBS and SRS can be effectively suppressed by combining the AF laser with a transverse magnetic field with tens of Tesla. The total reflectivity can be dramatically reduced by more than one order of magnitude. These results provide a potential reference for controlling SBS and SRS under the related parameters of inertial confinement fusion. 展开更多
关键词 stimulated Brillouin scattering stimulated Raman scattering alternating frequency laser transverse magnetic field
原文传递
Coupled Numerical Simulation of Electromagnetic and Flow Fields in a Magnetohydrodynamic Induction Pump
20
作者 He Wang Ying He 《Fluid Dynamics & Materials Processing》 EI 2024年第4期889-899,共11页
Magnetohydrodynamic(MHD)induction pumps are contactless pumps able to withstand harsh environments.The rate of fluid flow through the pump directly affects the efficiency and stability of the device.To explore the inf... Magnetohydrodynamic(MHD)induction pumps are contactless pumps able to withstand harsh environments.The rate of fluid flow through the pump directly affects the efficiency and stability of the device.To explore the influence of induction pump settings on the related delivery speed,in this study,a numerical model for coupled electromagnetic and flow field effects is introduced and used to simulate liquid metal lithium flow in the induction pump.The effects of current intensity,frequency,coil turns and coil winding size on the velocity of the working fluid are analyzed.It is shown that the first three parameters have a significant impact,while changes in the coil turns have a negligible influence.The maximum increase in working fluid velocity within the pump for the parameter combination investigated in this paper is approximately 618%.As the frequency is increased from 20 to 60 Hz,the maximum increase in the mean flow rate of the working fluid is approximately 241%.These research findings are intended to support the design and optimization of these devices. 展开更多
关键词 Magnetic fluid multi-physical field coupling induction pump numerical simulation liquid metal conveying
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部