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Resting-state brain network remodeling after different nerve reconstruction surgeries:a functional magnetic resonance imaging study in brachial plexus injury rats
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作者 Yunting Xiang Xiangxin Xing +6 位作者 Xuyun Hua Yuwen Zhang Xin Xue Jiajia Wu Mouxiong Zheng He Wang Jianguang Xu 《Neural Regeneration Research》 SCIE CAS 2025年第5期1495-1504,共10页
Distinct brain remodeling has been found after different nerve reconstruction strategies,including motor representation of the affected limb.However,differences among reconstruction strategies at the brain network lev... Distinct brain remodeling has been found after different nerve reconstruction strategies,including motor representation of the affected limb.However,differences among reconstruction strategies at the brain network level have not been elucidated.This study aimed to explore intranetwork changes related to altered peripheral neural pathways after different nerve reconstruction surgeries,including nerve repair,endto-end nerve transfer,and end-to-side nerve transfer.Sprague–Dawley rats underwent complete left brachial plexus transection and were divided into four equal groups of eight:no nerve repair,grafted nerve repair,phrenic nerve end-to-end transfer,and end-to-side transfer with a graft sutured to the anterior upper trunk.Resting-state brain functional magnetic resonance imaging was obtained 7 months after surgery.The independent component analysis algorithm was utilized to identify group-level network components of interest and extract resting-state functional connectivity values of each voxel within the component.Alterations in intra-network resting-state functional connectivity were compared among the groups.Target muscle reinnervation was assessed by behavioral observation(elbow flexion)and electromyography.The results showed that alterations in the sensorimotor and interoception networks were mostly related to changes in the peripheral neural pathway.Nerve repair was related to enhanced connectivity within the sensorimotor network,while end-to-side nerve transfer might be more beneficial for restoring control over the affected limb by the original motor representation.The thalamic-cortical pathway was enhanced within the interoception network after nerve repair and end-to-end nerve transfer.Brain areas related to cognition and emotion were enhanced after end-to-side nerve transfer.Our study revealed important brain networks related to different nerve reconstructions.These networks may be potential targets for enhancing motor recovery. 展开更多
关键词 brain functional networks end-to-end nerve transfer end-to-side nerve transfer independent component analysis nerve repair peripheral plexus injury resting-state functional connectivity
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Comparative Quantitative Analysis of Retinal Superficial Capillary Plexus in Patients with Retinal Vein Occlusion and Unaffected Fellow Eyes
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作者 Sinan Aptikadir Nelly Sivkova 《Open Journal of Ophthalmology》 2024年第3期218-228,共11页
Purpose: To evaluate optical coherence tomography angiography (OCT-A) data obtained from the superficial retinal capillary plexus of patients with retinal vein occlusion and comparative analysis with data registered f... Purpose: To evaluate optical coherence tomography angiography (OCT-A) data obtained from the superficial retinal capillary plexus of patients with retinal vein occlusion and comparative analysis with data registered from unaffected fellow eyes. Methods: The examined patients were classified into 2 groups: group 1—eyes with established retinal vein occlusion (n = 29) and group 2—unaffected fellow eyes of patients with retinal vein occlusion (n = 24). The scanning protocol “Angiography 3 × 3 mm” of Zeiss Cirrus HD-OCT 6000, AngioPlex Metrix was used to evaluate the retinal superficial capillary plexus. The analyzed parameters were vascular density and perfusion density, as well as the area, perimeter, and circularity of the foveolar avascular zone (FAZ). Results: The comparative analysis of FAZ parameters at the superficial capillary plexus (SCP) between group 1 (eyes with retinal vein occlusion) and group 2 (unaffected fellow eyes) showed significant results for the three parameters, respectively area (p = 0.003), perimeter (p ≤ 0.001), and circularity (p = 0.011) of FAZ. The comparative analysis of the vascular network at SCP in patients with diagnosed retinal vein occlusion and unaffected fellow eyes showed significant results for vascular density (VD) in the central (p = 0.038) and inner (p ≤ 0.001) zones as well as total VD (p ≤ 0.001) were statistically significant. Moreover, the results obtained in the study of vascular perfusion (VP) indicated significant results in the inner zone (p ≤ 0.001) and total VP (p = 0.001). Vascular perfusion in the central zone (p = 0.116) was the only parameter not to meet significant results. Conclusion: The current study observed a significant enlargement of the FAZ and loss of its circularity, along with a reduction in vascular network parameters at the superficial retinal capillary plexus level. 展开更多
关键词 Retinal Vein Occlusion Optical Coherence Tomography Angiography Superficial Retinal capillary plexus
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Small-worldness of brain networks after brachial plexus injury: a resting-state functional magnetic resonance imaging study 被引量:6
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作者 Wei-Wei Wang Ye-Chen Lu +4 位作者 Wei-Jun Tang Jun-Hai Zhang Hua-Ping Sun Xiao-Yuan Feng Han-Qiu Liu 《Neural Regeneration Research》 SCIE CAS CSCD 2018年第6期1061-1065,共5页
Research on brain function after brachial plexus injury focuses on local cortical functional reorganization,and few studies have focused on brain networks after brachial plexus injury.Changes in brain networks may hel... Research on brain function after brachial plexus injury focuses on local cortical functional reorganization,and few studies have focused on brain networks after brachial plexus injury.Changes in brain networks may help understanding of brain plasticity at the global level.We hypothesized that topology of the global cerebral resting-state functional network changes after unilateral brachial plexus injury.Thus,in this cross-sectional study,we recruited eight male patients with unilateral brachial plexus injury(right handedness,mean age of 27.9±5.4years old)and eight male healthy controls(right handedness,mean age of 28.6±3.2).After acquiring and preprocessing resting-state magnetic resonance imaging data,the cerebrum was divided into 90 regions and Pearson’s correlation coefficient calculated between regions.These correlation matrices were then converted into a binary matrix with affixed sparsity values of 0.1–0.46.Under sparsity conditions,both groups satisfied this small-world property.The clustering coefficient was markedly lower,while average shortest path remarkably higher in patients compared with healthy controls.These findings confirm that cerebral functional networks in patients still show smallworld characteristics,which are highly effective in information transmission in the brain,as well as normal controls.Alternatively,varied small-worldness suggests that capacity of information transmission and integration in different brain regions in brachial plexus injury patients is damaged. 展开更多
关键词 nerve regeneration brachial plexus injury functional magnetic resonance imaging small-world network small-world property topology properties functional reorganization clustering coefficient shortest path peripheral nerve injury neural regeneration
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DNA Sequencing by Capillary Electrophoresis Using Quasi-inter-penetrating Network Formed by Polyacrylamide and Poly(N-hydroxymethylacrylamide)
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作者 Wen Long ZHANG Yan Mei WANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第8期1061-1064,共4页
Quasi-interpenetrating network formed by polyacrylamide and poly (N-hydroxymethylacrylamide) was designed, synthesized, and tested for DNA sequencing by capillary electrophoresis. The performance of quasi-IPN on DNA... Quasi-interpenetrating network formed by polyacrylamide and poly (N-hydroxymethylacrylamide) was designed, synthesized, and tested for DNA sequencing by capillary electrophoresis. The performance of quasi-IPN on DNA sequencing was determined by the acrylamide to N-hydroxymethylacrylamide molar ratio and sequencing temperature. 展开更多
关键词 capillary electrophoresis DNA sequencing quasi-interpenetrating network.
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Quantitative analysis of retinal intermediate and deep capillary plexus in patients with retinal deep vascular complex ischemia
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作者 Xin-Xin Li Tian-Wei Qian +2 位作者 Ya-Nan Lyu Xun Xu Su-Qin Yu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2021年第7期1025-1033,共9页
AIM: To quantitatively analyze the retinal intermediate and deep capillary plexus(ICP and DCP) in patients with retinal deep vascular complex ischemia(RDVCI), using 3D projection artifacts removal(3D PAR) optical cohe... AIM: To quantitatively analyze the retinal intermediate and deep capillary plexus(ICP and DCP) in patients with retinal deep vascular complex ischemia(RDVCI), using 3D projection artifacts removal(3D PAR) optical coherence tomography angiography(OCTA).METHODS: RDVCI patients and gender-and agematched healthy controls were assessed and underwent OCTA examinations. The parafoveal vessel density(PFVD) of retinal deep vascular complex(DVC), ICP, and DCP were analyzed, and the percentage of reduction(PR) of PFVD was calculated.RESULTS: Twenty-four eyes in 22 RDVCI patients(20 in acute phase and 4 in chronic phase) and 24 eyes of 22 healthy subjects were enrolled as the control group. Significant reduction of PFVD in DVC, ICP, and DCP was observed in comparison with the controls(DVC: acute: 43.59%±6.58% vs 49.92%±5.49%, PR=12.69%;chronic: 43.50%±3.33% vs 51.20%±3.80%, PR=15.04%. ICP: acute: 40.28%±7.91% vs 46.97%±7.14%, PR=14.23%;chronic: 41.48%±2.87% vs 46.43%±3.29%, PR=10.66%. DCP: acute: 45.44%±8.27% vs 51.51%±9.97%, PR=11.79%;chronic: 37.78%±3.48% vs 51.73%±5.17%, PR=26.97%;all P<0.05). No significant PR difference was found among DVC, ICP, and DCP of RDVCI in acute phase(P=0.812), but significant difference in chronic phase(P=0.006, DVC vs DCP, ICP vs DCP). No significant difference in PR between acute and chronic phases in the DVC(P=0.735) or ICP(P=0.681) was found, but significant difference in the DCP(P=0.041).CONCLUSION: The PFVD of DVC, ICP, and DCP in RDVCI is significantly decreased in both acute and chronic phases. ICP impairment is stabilized from acute to chronic phase in RDVCI, whereas subsequent DCP impairment is uncovered and can be explained by ischemia-reperfusion damage. 展开更多
关键词 intermediate and deep capillary plexus 3D projection artifacts removal optical coherence tomography angiography retinal deep vascular complex ischemia
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A practical technique of reverse orbicularis oculi muscle resection with preserved subcutaneous capillary network for double eyelid blepharoplasty
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作者 Bin Yang Jinhua Xu +3 位作者 Enjing Wang Xinghai Gao Lun Liu Bin Xu 《Chinese Journal of Plastic and Reconstructive Surgery》 2022年第3期115-118,共4页
Background: Traditional full-incision double eyelid blepharoplasty has several significant disadvantages, including slow recovery and bilateral asymmetry, which results in high rates of patient dissatisfaction. These ... Background: Traditional full-incision double eyelid blepharoplasty has several significant disadvantages, including slow recovery and bilateral asymmetry, which results in high rates of patient dissatisfaction. These problems can be minimized using improved surgical techniques aimed at reducing tissue damage and bleeding, decreasing operation time, and especially at protecting the subcutaneous capillary network during the operation. We therefore aimed to guard the capillary network and reduce intraoperative bleeding using the practical technique of reverse orbicularis oculi muscle resection.Methods: Fifty cases of double eyelid blepharoplasty with traditional full-incision(group A) and 61 cases of reverse double eyelid blepharoplasty with a preserved capillary network(group B) were divided into two groups from October 1 to December 31, 2021 and from March 1 to May 31, 2022, respectively. The orbicularis oculi muscle was removed reversely from the front of the tarsal plate using double eyelid blepharoplasty, and the muscular membrane and subcutaneous capillary network were preserved. The operation time recorded in previous medical records was checked and compared with that of our novel technique. The recovery of double eyelid blepharoplasty was determined at 1, 4, and 12 weeks after the operation and patient satisfaction was also compared with that in previous medical records of patients in group A.Results: The reverse double eyelid blepharoplasty procedure was less complicated and easier to control than the traditional full-incision double eyelid blepharoplasty methodology. The average operation time of the double eyelid blepharoplasty cases with traditional full-incision was significantly greater than that of the cases of reverse double eyelid blepharoplasty with the capillary network preserved(45.68 ± 5.27 min and 31.11 ± 5.58 min,respectively;t=14.018 9, P=0.000 0). Patient satisfaction was 42% and 78.69%, respectively, at 1 week postoperation(χ~2=15.724 8, P=0.000 1), 62% and 90.16% at 4 weeks post-operation(χ~2=12.490 2, P=0.000 4),and 90% and 95.08%, at 12 weeks post-operation(χ~2=1.061 1, P=0.303 0).Conclusion: Reverse double eyelid blepharoplasty with preserved subcutaneous capillary network effectively decreases the operation time and improves post-operative patient satisfaction. It is a double eyelid blepharoplasty method worthy of popularization. 展开更多
关键词 Double eyelid blepharoplasty Subcutaneous capillary network Orbicularis oculi muscle Postoperative satisfaction
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Numerical Study of Thermal Performance of a Capillary Evaporator in a Loop Heat Pipe with Liquid-Saturated Wick 被引量:1
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作者 Masahito Nishikawara Hosei Nagano +1 位作者 Laetitia Mottet Marc Prat 《Journal of Electronics Cooling and Thermal Control》 2014年第4期118-127,共10页
Heat transfer of a capillary evaporator in a loop heat pipe was analyzed through 3D numerical simulations to study the effects of the thermal conductivity of the wick, the contact area between the casing and the wick,... Heat transfer of a capillary evaporator in a loop heat pipe was analyzed through 3D numerical simulations to study the effects of the thermal conductivity of the wick, the contact area between the casing and the wick, and the subcooling in the compensation chamber (CC) on the thermal performance of the evaporator. A pore network model with a distribution of pore radii was used to simulate liquid flow in the porous structure of the wick. To obtain high accuracy, fine meshes were used at the boundaries among the casing, the wick, and the grooves. Distributions of temperature, pressure, and mass flow rate were compared for polytetra-fluoroethylene (PTFE) and stainless steel wicks. The thermal conductivity of the wick and the contact area between the casing and the wick significantly impacted thermal performance of the evaporator heat-transfer coefficient and the heat leak to the CC. The 3D analysis provided highly accurate values for the heat leak;in some cases, the heat leaks of PTFE and stainless steel wicks showed little differences. In general, the heat flux is concentrated at the boundaries between the casing, the wick, and the grooves;therefore, thermal performance can be optimized by increasing the length of the boundary. 展开更多
关键词 capillary EVAPORATOR Loop HEAT Pipe Numerical Simulation PORE network Model TWO-PHASE HEAT Transfer
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An Algorithm to Determine the Truncated Weibull Parameters for Distribution of Throats and Pores in Random Network Models
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作者 Fei Shi Junda Wu +2 位作者 Tao Chang Cangjun Sun Xiaozhang Wu 《Journal of Geoscience and Environment Protection》 2022年第10期46-53,共8页
In random network models, sizes for pores and throats are distributed according to a truncated Weibull distribution. As a result, parameters defining the shape of the distribution are critical for the characteristic o... In random network models, sizes for pores and throats are distributed according to a truncated Weibull distribution. As a result, parameters defining the shape of the distribution are critical for the characteristic of the network. In this paper, an algorithm to distribute pores and throats in random network was established to more representatively describe the topology of porous media. First, relations between Weibull parameters and the distribution of dimensionless throat sizes were studied and a series of standard curves were obtained. Then, by analyzing the capillary pressure curve of the core sample, frequency distribution histogram of throat sizes was obtained. All the sizes were transformed to dimensionless numbers ranged from 0 to 1. Curves of the core were compared to the standard curves, and truncated Weibull parameters could be determined according an inverse algorithm. Finally, aspect ratio and average length of throats were adjusted to simultaneously fit the porosity and the capillary pressure curves and the whole network was established. The predicted relative permeability curves were in good agreement with the experimental data of cores, indicating the validity of the algorithm. 展开更多
关键词 Random network Models capillary Pressure Curve Average Dimensionless Throat Sizes Truncated Weibull Distribution
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不同程度非增殖性糖尿病视网膜病变的OCTA表现
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作者 代梦欢 李冬莉 +5 位作者 崔忆辛 申璐 李齐瑞 饶玲娜 郭姝蓉 袁玲 《国际眼科杂志》 2024年第2期307-311,共5页
目的:利用光学相干断层扫描血管成像(OCTA)探讨不同程度非增殖性糖尿病视网膜病变(NPDR)的表现差异。方法:横断面研究。纳入糖尿病患者77例77眼,分为非DR组(NDR,23眼)和NPDR组(54眼),其中轻度NPDR(20眼)、中度NPDR(20眼)和重度NPDR(14眼... 目的:利用光学相干断层扫描血管成像(OCTA)探讨不同程度非增殖性糖尿病视网膜病变(NPDR)的表现差异。方法:横断面研究。纳入糖尿病患者77例77眼,分为非DR组(NDR,23眼)和NPDR组(54眼),其中轻度NPDR(20眼)、中度NPDR(20眼)和重度NPDR(14眼)。NDR组与NPDR组的黄斑区中央凹无血管区(FAZ)面积、浅层和深层毛细血管密度(SSP和DSP)、视力(LogMAR)进行比较,不同程度NPDR的视力、FAZ面积、SSP和DSP水平进行比较,FAZ面积、视力、SSP和DSP与病情严重程度进行相关性分析。结果:与NDR组相比,NPDR组的视力值(LogMAR)、黄斑区FAZ面积增大,SSP和DSP降低(P<0.05);不同程度NPDR的视力、FAZ面积、SSP和DSP水平差异显著(P<0.05)。视力(LogMAR)、FAZ面积与病情严重程度呈正相关,SSP和DSP与病情严重程度呈负相关。结论:随着NPDR病情的进展,视力(LogMAR)、FAZ面积增大,SSP和DSP降低。 展开更多
关键词 非增殖性糖尿病视网膜病变 光学相干断层扫描血管成像(OCTA) 视力 黄斑区中央凹无血管区面积 浅层毛细血管丛 深层毛细血管丛
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一种轻薄型光伏/光热集热器性能分析及实验研究
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作者 陈艺鑫 陈健斌 +2 位作者 李旭东 李勇 刁永发 《发电技术》 CSCD 2024年第4期666-674,共9页
【目的】野外作业和户外生存对能源的需求越来越大,现有常规供能方式存在一些重要缺陷,例如常规发电机需携带大量燃油、蓄电池重量大等。太阳能光伏/光热(photovoltaic/thermal,PV/T)发电技术可有效解决户外生存和野外作业能源缺乏的问... 【目的】野外作业和户外生存对能源的需求越来越大,现有常规供能方式存在一些重要缺陷,例如常规发电机需携带大量燃油、蓄电池重量大等。太阳能光伏/光热(photovoltaic/thermal,PV/T)发电技术可有效解决户外生存和野外作业能源缺乏的问题,而现有的PV/T集热器多为刚性结构、重量大而不便于携带。【方法】提出一种基于铜铟镓硒薄膜电池和毛细管网相结合的轻薄型PV/T组件,通过实验的方法研究该组件的集热性能及水流量对组件光电、光热转换效率的影响。【结果】在典型上海气候下,该组件的全天电效率、热效率分别为13.04%、22.50%;在平均辐照度为760 W/m^(2)的实验条件下,水流量为2.1 L/min时,此PV/T的集能性能最优;毛细管网内冷却水可有效降低电池温度(10℃)、提高能量利用效率(23.94%)。【结论】该组件具有高功率密度、轻便灵活的特点,可用于野外作业、户外生存时的能源供给,为户外能源装备的设计提供了新思路。 展开更多
关键词 光伏/光热集热器 毛细管网 便携式能源装备
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多孔介质各向异性动态渗透率模型
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作者 裴雪皓 刘月田 +3 位作者 林子愉 樊平天 米辽 薛亮 《石油勘探与开发》 EI CSCD 北大核心 2024年第1期173-181,共9页
基于迂曲毛细管网络模型,推导建立了各向异性渗透率与岩石正应变间的关系式,即各向异性动态渗透率模型(ADPM),采用孔隙尺度流动模拟对模型进行了验证,并对单轴应变过程进行了计算,分析了变形过程中影响不同方向渗透率变化的主要因素。... 基于迂曲毛细管网络模型,推导建立了各向异性渗透率与岩石正应变间的关系式,即各向异性动态渗透率模型(ADPM),采用孔隙尺度流动模拟对模型进行了验证,并对单轴应变过程进行了计算,分析了变形过程中影响不同方向渗透率变化的主要因素。研究表明:层状油气藏开采的单轴应变过程中,有效面孔率对各方向的渗透率影响规律一致,随着有效面孔率的减小,渗透率对应变的敏感程度增大;垂直于压缩方向的渗透率对应变的敏感程度随迂曲度的增加而减小,沿压缩方向的渗透率对应变的敏感程度随迂曲度的增加而增大。初始各方向迂曲度相同的层状油气藏,在压力下降的过程中,迂曲度对各方向渗透率变化幅度的相对关系起决定性作用,迂曲度小于1.6时,岩石水平方向渗透率的降幅要高于垂向渗透率,迂曲度大于1.6时则相反,传统动态渗透率模型无法表征这一现象。经孔隙尺度模拟实验数据的验证,新模型拟合精度高,可以有效表征不同方向变形对各方向渗透率的影响。 展开更多
关键词 多孔介质 动态渗透率 各向异性 毛细管网络模型 迂曲度 正应变 流动模拟 渗透率变化特征
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Anisotropic dynamic permeability model for porous media
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作者 PEI Xuehao LIU Yuetian +3 位作者 LIN Ziyu FAN Pingtian MI Liao XUE Liang 《Petroleum Exploration and Development》 SCIE 2024年第1期193-202,共10页
Based on the tortuous capillary network model,the relationship between anisotropic permeability and rock normal strain,namely the anisotropic dynamic permeability model(ADPM),was derived and established.The model was ... Based on the tortuous capillary network model,the relationship between anisotropic permeability and rock normal strain,namely the anisotropic dynamic permeability model(ADPM),was derived and established.The model was verified using pore-scale flow simulation.The uniaxial strain process was calculated and the main factors affecting permeability changes in different directions in the deformation process were analyzed.In the process of uniaxial strain during the exploitation of layered oil and gas reservoirs,the effect of effective surface porosity on the permeability in all directions is consistent.With the decrease of effective surface porosity,the sensitivity of permeability to strain increases.The sensitivity of the permeability perpendicular to the direction of compression to the strain decreases with the increase of the tortuosity,while the sensitivity of the permeability in the direction of compression to the strain increases with the increase of the tortuosity.For layered reservoirs with the same initial tortuosity in all directions,the tortuosity plays a decisive role in the relative relationship between the variations of permeability in all directions during pressure drop.When the tortuosity is less than 1.6,the decrease rate of horizontal permeability is higher than that of vertical permeability,while the opposite is true when the tortuosity is greater than 1.6.This phenomenon cannot be represented by traditional dynamic permeability model.After the verification by experimental data of pore-scale simulation,the new model has high fitting accuracy and can effectively characterize the effects of deformation in different directions on the permeability in all directions. 展开更多
关键词 porous media dynamic permeability ANISOTROPY capillary network model TORTUOSITY normal strain flow simulation permeability change characteristics
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Acute macular neuroretinopathy following COVID-19 infection:Three case reports
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作者 Chao Bi Chun-Mei Huang +2 位作者 Ye-Qiang Shi Chao Huang Tao Yu 《World Journal of Clinical Cases》 SCIE 2024年第25期5775-5783,共9页
BACKGROUND During the Coronavirus disease 2019(COVID-19)pandemic,a notable increase in acute macular neuroretinopathy(AMN)cases was observed.This study aimed to investigate the potential association between AMN and CO... BACKGROUND During the Coronavirus disease 2019(COVID-19)pandemic,a notable increase in acute macular neuroretinopathy(AMN)cases was observed.This study aimed to investigate the potential association between AMN and COVID-19 by examining 3 cases in China.CASE SUMMARY The first case involved a 30-year-old man who presented with progressive vision loss following a COVID-19 infection.Optical coherence tomography(OCT)and near-infrared imaging identified hallmark AMN lesions,hyperreflective disruptions within the outer plexiform layer,and hyporeflective anomalies in the ellipsoid zone,leading to an AMN diagnosis.Despite partial visual recovery,OCT angiography(OCTA)revealed persistent microvascular changes,specifically a decreased vascular density in the deep capillary plexus.The second case was a 24-year-old woman who experienced blurred vision and exhibited bilateral cottonwool spots on fundus examination post-COVID-19.Imaging confirmed the presence of AMN along with paracentral acute middle maculopathy(PAMM).Follow-up OCTA found a progressive reduction in vascular density,indicating ongoing microvascular compromise.The third case was a 28-year-old woman who reported sensations of occlusion in her right eye following a COVID-19 infection.Imaging confirmed both AMN and PAMM,revealing similar decreases of microvascular density on OCTA despite a significant improvement in visual acuity.We noted that all 3 patients had received the COVID-19 vaccine prior to the appearance of symptoms.CONCLUSION The findings highlight the diagnostic utility of advanced ocular imaging in detecting AMN in COVID-19 patients and the importance of comprehensive eye examinations. 展开更多
关键词 Acute macular neuroretinopathy Paracentral acute middle maculopathy COVID-19 Optical coherence tomography Optical coherence tomography angiography Deep capillary plexus Case report
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西安某综合体项目毛细管网辐射空调系统重难点问题浅析
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作者 蒋能飞 尹畅昱 严载竟 《制冷》 2024年第4期5-9,共5页
本文结合西安某综合体毛细管网辐射空调系统设计实例,对毛细管网辐射空调系统的室内设计参数、送风状态、送风方式、水管管材等问题进行了浅析与归纳,为辐射空调系统在综合体项目中的应用提供参考借鉴。
关键词 毛细管网辐射空调系统 送风 水管管材 浅析
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产前使用皮质激素对早产鼠脉络丛毛细血管成熟度的影响 被引量:9
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作者 刘敬 卢静 +2 位作者 张为远 乔欣 王琪 《实用儿科临床杂志》 CAS CSCD 北大核心 2008年第2期104-105,共2页
目的探讨产前使用皮质激素能否促进早产鼠脉络丛毛细血管的成熟度。方法将受孕SD大鼠随机分为实验和对照组。实验组分别在受孕第13、14、15、16天开始予地塞米松腹腔注射,4mg/(kg.次),1次/d,连用2d;对照组腹腔注射9g/L盐水。二组孕鼠分... 目的探讨产前使用皮质激素能否促进早产鼠脉络丛毛细血管的成熟度。方法将受孕SD大鼠随机分为实验和对照组。实验组分别在受孕第13、14、15、16天开始予地塞米松腹腔注射,4mg/(kg.次),1次/d,连用2d;对照组腹腔注射9g/L盐水。二组孕鼠分别在最后一次注射地塞米松或9g/L盐水24h后行剖宫产出仔鼠,称体质量处死后取脑,并称脑质量,而后用30g/L戊二醛固定,透射电镜观察其脉络丛毛细血管内皮基膜状态及毛细血管内皮细胞间的紧密连接情况。二组体质量、脑质量比较采用t检验。结果电镜下,实验和对照组比较,毛细血管间的连接变得更为紧密;毛细血管基膜的厚度增加;膜蛋白颗粒排列趋于紧密。二组早产鼠各时间点的出生体质量和脑质量均无显著性差异(Pa>0.05)。结论产前使用皮质激素可在一定程度上促进早产鼠脉络丛毛细血管成熟。 展开更多
关键词 早产 皮质激素 脉络丛 毛细血管
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舌粘膜及粘膜下血管网的构筑及其临床意义 被引量:6
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作者 吴海燕 何光篪 陈尔瑜 《解剖学报》 CAS 1988年第4期357-360,450,共5页
本研究应用手术显微镜和扫描电镜观察了人舌粘膜的微血管构筑。舌深动脉长支和舌背动脉终支在舌粘膜下形成一完整的致密动脉网,跨越界沟和舌正中线,成为一整体。由动脉网发出微动脉支进入舌粘膜内,形成粘膜内的毛细血管网和各种乳头毛... 本研究应用手术显微镜和扫描电镜观察了人舌粘膜的微血管构筑。舌深动脉长支和舌背动脉终支在舌粘膜下形成一完整的致密动脉网,跨越界沟和舌正中线,成为一整体。由动脉网发出微动脉支进入舌粘膜内,形成粘膜内的毛细血管网和各种乳头毛细血管丛。另外,还讨论了舌粘膜下馓血管构筑和舌瓣设计与临床舌诊的关系。 展开更多
关键词 微血管构筑 动脉网 毛细血管网(丛) 舌瓣
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基于太阳能热水的毛细管网壁面低温辐射采暖系统 被引量:11
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作者 冯国会 崔洁 +2 位作者 黄凯良 李慧星 郭慧宇 《沈阳建筑大学学报(自然科学版)》 CAS 北大核心 2013年第2期320-326,共7页
目的分析毛细管网作为高效的散热末端,应用于太阳能热水采暖系统的可行性.方法建立了以毛细管网为散热末端的太阳能热水采暖系统,测试铺设于壁面的毛细管网的散热性能以及其对室内热性能的影响,对比了毛细管网与普通地板采暖散热末端的... 目的分析毛细管网作为高效的散热末端,应用于太阳能热水采暖系统的可行性.方法建立了以毛细管网为散热末端的太阳能热水采暖系统,测试铺设于壁面的毛细管网的散热性能以及其对室内热性能的影响,对比了毛细管网与普通地板采暖散热末端的经济性.结果研究表明:毛细管网墙壁采暖的传热系数k=1.638 W/(m2.k),换热效率为79.9%;在供回水温度40~35℃,室外平均温度-22℃情况下,运行期间能使房间平均温度维持在17.65℃;对太阳能热水采暖系统而言,毛细管网比普通地板采暖散热末端具有更好的综合性能,成本节约达9%.结论毛细管席间距很小的平行毛细管均匀分布,热交换面积大,同时毛细管网与室内通过辐射方式换热,使室内温度分布均匀,且提供了最佳的热舒适性;太阳能与毛细管辐射供暖系统相结合,不仅节省了大量能源,还提高了空间的利用率. 展开更多
关键词 太阳能采暖 毛细管网 散热性能 经济性
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基于模型和神经网络的绝热毛细管快速仿真方法 被引量:16
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作者 丁国良 张春路 刘浩 《工程热物理学报》 EI CAS CSCD 北大核心 2000年第2期133-137,共5页
为简化毛细管模型,采用分相集中参数方法,将平均比容的权重因子作为两相区简化的特征参数,用人工神经网络方法建立特征参数与其影响参数之间的非线性映射。神经网络的学习样本采用工质R12,检验样本包括R12、R22、R134... 为简化毛细管模型,采用分相集中参数方法,将平均比容的权重因子作为两相区简化的特征参数,用人工神经网络方法建立特征参数与其影响参数之间的非线性映射。神经网络的学习样本采用工质R12,检验样本包括R12、R22、R134a和R600a等多种工质。在常用制冷空调工况范围内,该简化模型与分布参数模型相比,平均偏差03%,计算速度提高1个数量级。 展开更多
关键词 绝热毛细管 模型 人工神经网络 制冷装置 仿真
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苹果切片干燥收缩变形的孔道网络模拟及试验 被引量:11
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作者 徐英英 文怀兴 +3 位作者 谭礼斌 袁越锦 王栋 袁月定 《农业工程学报》 EI CAS CSCD 北大核心 2021年第12期289-298,共10页
为揭示果蔬干燥收缩变形的传热传质与应力应变的机理,确定果蔬微孔结构特性及内部毛细力等因素对其干燥过程的影响,该研究运用孔道网络方法、热质传递原理和细观力学理论等交叉学科知识,构建了孔隙尺度下果蔬切片干燥收缩变形的孔道网... 为揭示果蔬干燥收缩变形的传热传质与应力应变的机理,确定果蔬微孔结构特性及内部毛细力等因素对其干燥过程的影响,该研究运用孔道网络方法、热质传递原理和细观力学理论等交叉学科知识,构建了孔隙尺度下果蔬切片干燥收缩变形的孔道网络模型,采用VC++开发孔道网络求解程序,模拟分析了果蔬切片的湿分场、温度场以及应力应变场等情况,并以苹果切片作为果蔬典型代表进行了热风干燥试验及模型验证。结果表明:湿含量、温度和收缩变形率的模拟值与试验值的相对误差小于10%,模型可有效模拟果蔬干燥热质传递与应力应变的收缩变形真实过程,再现了干燥过程中的“非规则收缩变形”现象;孔道网络模拟的湿分场、温度场及应力应变场均呈现为不规则非对称变化规律,产生了明显的干斑、湿斑、非规则干燥前沿等;毛细应力和湿应力对果蔬干燥收缩变形影响较大,其中毛细应力是引起非规则收缩变形的主导因素;孔隙结构参数对果蔬干燥过程影响显著;孔隙率越大,干燥时间越长,毛细应力越小;配位数越大,毛细应力越大,干燥时间越长;孔隙直径分布呈现均一直径分布规律的物料产生的毛细应力大,其次为孔隙直径分布呈现正态分布规律的物料和试验物料分布。研究结果为果蔬干燥品质及工艺优化分析提供了一定的理论基础。 展开更多
关键词 干燥 模型 毛细力 孔道网络 传热传质 应力应变
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利用三维随机网络模型研究油水两相流动 被引量:27
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作者 姚军 陶军 李爱芬 《石油学报》 EI CAS CSCD 北大核心 2007年第2期94-97,101,共5页
利用计算机模拟建立了由孔隙孔喉组成的三维立方网络模型,孔隙孔喉的大小按正态分布随机产生。分析了流体在模型中的流动过程,建立了求解毛细管压力和相对渗透率的数学模型,对模型进行求解后得到了与理论相符的结果。平均配位数和模型... 利用计算机模拟建立了由孔隙孔喉组成的三维立方网络模型,孔隙孔喉的大小按正态分布随机产生。分析了流体在模型中的流动过程,建立了求解毛细管压力和相对渗透率的数学模型,对模型进行求解后得到了与理论相符的结果。平均配位数和模型大小对计算结果影响的研究结果表明:增加平均配位数可以提高模型连通性,计算结果与理论分析结果一致,而模型大小对计算结果的影响并不明显。与其他理想模型相比,利用三维随机网络模型可以更真实地研究油水两相流动特征。 展开更多
关键词 网络模型 多相流 毛细管压力 相对渗透率 配位数 数学模型
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