目的探讨老年急性冠状动脉(冠脉)综合征患者贫血对预后的影响。方法检索PubMed、Scopus、OVID、Cochrane library、Web of Science、Embase、中国知网、中国生物医学、万方、维普数据库中关于贫血与老年急性冠脉综合征预后影响的相关研...目的探讨老年急性冠状动脉(冠脉)综合征患者贫血对预后的影响。方法检索PubMed、Scopus、OVID、Cochrane library、Web of Science、Embase、中国知网、中国生物医学、万方、维普数据库中关于贫血与老年急性冠脉综合征预后影响的相关研究。检索时限为建库至2022年12月10日,由两名评审员按文献的纳入和排除标准独立完成文献筛选及数据提取,采用Stata 16.0软件进行统计分析。结果在最初检索的1399篇文献中,13篇9540例患者符合纳入标准,平均年龄70.3岁,合并贫血2872例(30.1%),非贫血患者6668例。老年急性冠脉综合征贫血与非贫血患者比较,贫血增加患者的死亡风险(RR=2.28,95%CI:1.74~3.00),同时亦增加缺血(RR=1.36,95%CI:1.13~1.64)和出血事件(RR=2.18,95%CI:1.59~3.01)的发生风险(均P<0.05)。结论贫血增加老年急性冠脉综合征患者死亡风险,与不良预后相关。展开更多
As one of the most ideal display approaches,holographic 3-dimensional(3D)display has always been a research hotspot since the holographic images reproduced in such system are very similar to what humans see the actual...As one of the most ideal display approaches,holographic 3-dimensional(3D)display has always been a research hotspot since the holographic images reproduced in such system are very similar to what humans see the actual environment.However,current holographic 3D displays suffer from critical bottlenecks of narrow viewing angle and small size.Here,we propose a tunable liquid crystal grating-based holographic 3D display system with wide viewing angle and large size.Our tunable liquid crystal grating,providing an adjustable period and the secondary diffraction of the reconstructed image,enables to simultaneously implement two different hologram generation methods in achieving wide viewing angle and enlarged size,respectively.By using the secondary diffraction mechanism of the tunable liquid crystal grating,the proposed system breaks through the limitations of narrow viewing angle and small size of holographic 3D display.The proposed system shows a viewing angle of 57.4°,which is nearly 7 times of the conventional case with a single spatial light modulator,and the size of the reconstructed image is enlarged by about 4.2.The proposed system will have wide applications in medical diagnosis,advertising,education and entertainment and other fields.展开更多
Holographic 3D display is highly desirable for numerous applications ranging from medical treatments to military affairs.However,it is challenging to simultaneously achieve large viewing angle and high-fidelity color ...Holographic 3D display is highly desirable for numerous applications ranging from medical treatments to military affairs.However,it is challenging to simultaneously achieve large viewing angle and high-fidelity color reconstruction due to the intractable constraints of existing technology.Here,we conceptually propose and experimentally demonstrate a simple and feasible pathway of using a well-designed color liquid crystal grating to overcome the inevitable chromatic aberration and enlarge the holographic viewing angle,thus enabling large-viewing-angle and color holographic 3D display.The use of color liquid crystal grating allows performing secondary diffraction modulation on red,green and blue reproduced images simultaneously and extending the viewing angle in the holographic 3D display system.In principle,a chromatic aberration-free hologram generation mechanism in combination with the color liquid crystal grating is proposed to pave the way for on such a superior holographic 3D display.The proposed system shows a color viewing angle of~50.12°,which is about 7 times that of the traditional system with a single spatial light modulator.This work presents a paradigm for achieving desirable holographic 3D display,and is expected to provide a new way for the wide application of holographic display.展开更多
An ideal holographic 3D display should have the characteristics of large viewing angle,full color,and low speckle noise.However,the viewing angle of the holographic 3D display is usually limited by existing strategies...An ideal holographic 3D display should have the characteristics of large viewing angle,full color,and low speckle noise.However,the viewing angle of the holographic 3D display is usually limited by existing strategies,which vastly hinders its extensive application.In this paper,a large viewing angle holographic 3D display system based on maximum diffraction modulation is proposed.The core of the proposed system comprises the spatial light modulators(SLMs)and liquid crystal grating.We also present a new feasible scheme for the realization of large viewing angle holographic 3D display.This is achieved by considering the maximum diffraction angle of SLM as the limited diffraction modulation range of each image point.By doing so,we could not only give access to the maximum hologram size of the object,but also tune the reconstructed image of secondary diffraction by using a self-engineered liquid crystal grating.More importantly,the proposed maximum diffraction modulation scheme enables the viewing angle of the proposed system to be enlarged to 73.4°.The proposed system has huge application potential in the fields such as education,culture,and entertainment.展开更多
Holographic 3D display technology,widely considered the ultimate solution for real 3D display,has broad applications in fields including advertisement,industrial manufacturing and military.However,it is difficult to s...Holographic 3D display technology,widely considered the ultimate solution for real 3D display,has broad applications in fields including advertisement,industrial manufacturing and military.However,it is difficult to simultaneously realize color holographic 3D display with wide viewing angle and high brightness required for an immersive visual experience.Here,a novel holographic 3D display system based on a customized achromatic liquid crystal grating and a phase-only spatial light modulator is proposed.Thanks to the secondary diffraction performed by the achromatic liquid crystal grating,nine secondary diffraction images of red,green and blue channels overlap in space in time sequence.Additionally,a high brightness hologram encoding method is developed,which introduces a frequency loss function with dynamic weights to ensure that differences of all frequency components in the frequency domain can be learned.The proposed method dramatically enhances light energy utilization by a factor of five,resulting in significantly brighter reconstructed images while substantially attenuating background noise in non-target regions.This groundbreaking system,achieving a remarkable~65°wide viewing angle with good image quality and high brightness,represents a significant advancement in holographic technology,offering a comprehensive solution for wide-viewing-angle,high-brightness,color 3D displays with potential applications across diverse technological domains.展开更多
文摘目的探讨老年急性冠状动脉(冠脉)综合征患者贫血对预后的影响。方法检索PubMed、Scopus、OVID、Cochrane library、Web of Science、Embase、中国知网、中国生物医学、万方、维普数据库中关于贫血与老年急性冠脉综合征预后影响的相关研究。检索时限为建库至2022年12月10日,由两名评审员按文献的纳入和排除标准独立完成文献筛选及数据提取,采用Stata 16.0软件进行统计分析。结果在最初检索的1399篇文献中,13篇9540例患者符合纳入标准,平均年龄70.3岁,合并贫血2872例(30.1%),非贫血患者6668例。老年急性冠脉综合征贫血与非贫血患者比较,贫血增加患者的死亡风险(RR=2.28,95%CI:1.74~3.00),同时亦增加缺血(RR=1.36,95%CI:1.13~1.64)和出血事件(RR=2.18,95%CI:1.59~3.01)的发生风险(均P<0.05)。结论贫血增加老年急性冠脉综合征患者死亡风险,与不良预后相关。
基金supported by the National Key Research and Development Program of China(2021YF82802100)the National Natural Science Foundation of China(62020106010,61927809).
文摘As one of the most ideal display approaches,holographic 3-dimensional(3D)display has always been a research hotspot since the holographic images reproduced in such system are very similar to what humans see the actual environment.However,current holographic 3D displays suffer from critical bottlenecks of narrow viewing angle and small size.Here,we propose a tunable liquid crystal grating-based holographic 3D display system with wide viewing angle and large size.Our tunable liquid crystal grating,providing an adjustable period and the secondary diffraction of the reconstructed image,enables to simultaneously implement two different hologram generation methods in achieving wide viewing angle and enlarged size,respectively.By using the secondary diffraction mechanism of the tunable liquid crystal grating,the proposed system breaks through the limitations of narrow viewing angle and small size of holographic 3D display.The proposed system shows a viewing angle of 57.4°,which is nearly 7 times of the conventional case with a single spatial light modulator,and the size of the reconstructed image is enlarged by about 4.2.The proposed system will have wide applications in medical diagnosis,advertising,education and entertainment and other fields.
基金supported by the National Key Research and Development Program of China(2021YFB2802100)the National Natural Science Foundation of China(62020106010,62275009,and U22A2079)。
文摘Holographic 3D display is highly desirable for numerous applications ranging from medical treatments to military affairs.However,it is challenging to simultaneously achieve large viewing angle and high-fidelity color reconstruction due to the intractable constraints of existing technology.Here,we conceptually propose and experimentally demonstrate a simple and feasible pathway of using a well-designed color liquid crystal grating to overcome the inevitable chromatic aberration and enlarge the holographic viewing angle,thus enabling large-viewing-angle and color holographic 3D display.The use of color liquid crystal grating allows performing secondary diffraction modulation on red,green and blue reproduced images simultaneously and extending the viewing angle in the holographic 3D display system.In principle,a chromatic aberration-free hologram generation mechanism in combination with the color liquid crystal grating is proposed to pave the way for on such a superior holographic 3D display.The proposed system shows a color viewing angle of~50.12°,which is about 7 times that of the traditional system with a single spatial light modulator.This work presents a paradigm for achieving desirable holographic 3D display,and is expected to provide a new way for the wide application of holographic display.
基金supported by the National Natural Science Foundation of China(62020106010,62275009,U22A2079,11974258).
文摘An ideal holographic 3D display should have the characteristics of large viewing angle,full color,and low speckle noise.However,the viewing angle of the holographic 3D display is usually limited by existing strategies,which vastly hinders its extensive application.In this paper,a large viewing angle holographic 3D display system based on maximum diffraction modulation is proposed.The core of the proposed system comprises the spatial light modulators(SLMs)and liquid crystal grating.We also present a new feasible scheme for the realization of large viewing angle holographic 3D display.This is achieved by considering the maximum diffraction angle of SLM as the limited diffraction modulation range of each image point.By doing so,we could not only give access to the maximum hologram size of the object,but also tune the reconstructed image of secondary diffraction by using a self-engineered liquid crystal grating.More importantly,the proposed maximum diffraction modulation scheme enables the viewing angle of the proposed system to be enlarged to 73.4°.The proposed system has huge application potential in the fields such as education,culture,and entertainment.
基金supported by the National Natural Science Foundation of China under Grant Nos:U22A2079,U21B2034,62275009,623B2008 and 62175006.
文摘Holographic 3D display technology,widely considered the ultimate solution for real 3D display,has broad applications in fields including advertisement,industrial manufacturing and military.However,it is difficult to simultaneously realize color holographic 3D display with wide viewing angle and high brightness required for an immersive visual experience.Here,a novel holographic 3D display system based on a customized achromatic liquid crystal grating and a phase-only spatial light modulator is proposed.Thanks to the secondary diffraction performed by the achromatic liquid crystal grating,nine secondary diffraction images of red,green and blue channels overlap in space in time sequence.Additionally,a high brightness hologram encoding method is developed,which introduces a frequency loss function with dynamic weights to ensure that differences of all frequency components in the frequency domain can be learned.The proposed method dramatically enhances light energy utilization by a factor of five,resulting in significantly brighter reconstructed images while substantially attenuating background noise in non-target regions.This groundbreaking system,achieving a remarkable~65°wide viewing angle with good image quality and high brightness,represents a significant advancement in holographic technology,offering a comprehensive solution for wide-viewing-angle,high-brightness,color 3D displays with potential applications across diverse technological domains.
