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501 results on '"Zhang, Xiangxiang"'

1. Design of laser uniform illumination system based on aspheric lens and compound ellipsoidal cavity

Author

Lu, Yu, Zhang, Xiangxiang, Wu, Ruilong, and Yang, Yi

Subjects
Physics - Optics
Abstract

In order to achieve uniform laser illumination with small aperture diameter and large field Angle,study laser active illumination system.An aspheric mirror combined with a composite ellipsoidal cavity is designed to achieve uniform illumination in this paper.Through an aspheric mirror,the fundamental mode of Gaussian beam is shaped into double Gaussian radiation and Flat-top radiation.The double Gaussian radiation rays are reflected again by the complex ellipsoidal cavity and decomposed into equal radiation flux,which is superimposed with the through Flat-top radiation rays to form a uniform distribution.The parameters of the complex ellipsoidal cavity are obtained by mapping equalization algorithm.After the superposition of the aspherical transmission Flat-top shaping and the composite ellipsoidal cavity secondary reflection shaping,the aperture is 29.7mm,whose aperture angle is 84.0 degrees,and the uniformity is 92.7% with 2m distance and 3.6m diameter.The optimization of uniformity is influenced by three factors:RMS,transmission and reflection power density ratio MT/R and transmission and reflection overlap degree.RMS and MT/R determine the design effect of the composite ellipsoidal cavity, which depends on the maximum reflection Angle and transmission Angle.MT/R is negatively correlated with the maximum reflection of Angle,and RMS is positively correlated with the transmission Angle.When the maximum reflection Angle is set to 32.0 degrees and the transmission Angle to 8.0 degrees,the minimum root-mean-square focusing radius is 108.6um,and the minimum effective transmission reflection power density ratio is 1.07.The degree overlap of transmission and reflection directly affects the uniformity of the target plane.The degree of transmission and reflection is adjusted by setting an adjustment factor.When the adjustment factor is 0.9,the uniformity of the target plane reaches the maximum., Comment: 7 pages, 13 figures

Published
2023

14. Mechanism and protective measures of low fertility quality in men caused by ionizing radiation

Author

Zhang Xiangxiang, Yang Yong

Subjects
ionizing radiation, ionizing radiation protection, sperm, male, fertility quality, Medicine
Abstract

In the modern world，ionizing radiation has been prevalent in daily lives and work environment due to rapid development of nuclear technology. It is invisible and exerts multiple adverse effects on various human systems and organs. As one of the cells that are highly-sensitive to ionizing radiation，male testicular germ cells are highly-susceptible to damage and exposure to varying levels of ionizing radiation can cause a range of adverse effects，including sperm parameters and sperm chromosomes and DNA，leading to a decline in male fertility and abnormal offspring development. Consequently，it is of utmost importance to promote rational and scientific protection against ionizing radiation damage while attaching importance to the life-saving cause of safeguarding male fertility，which is of great importance to the well-being of future generations. In this article，the biological effect of ionizing radiation on male reproductive organs，the damage effect of ionizing radiation on male testicular germ cells，and the protection of declined male fertility caused by ionizing radiation were illustrated，aiming to provide reference for relevant clinical trials.

Published
2023
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22. CMSN: Continuous Multi-stage Network and Variable Margin Cosine Loss for Temporal Action Proposal Generation

Author

Hu, Yushuai, Jin, Yaochu, Li, Runhua, and Zhang, Xiangxiang

Subjects
Computer Science - Computer Vision and Pattern Recognition
Abstract

Accurately locating the start and end time of an action in untrimmed videos is a challenging task. One of the important reasons is the boundary of action is not highly distinguishable, and the features around the boundary are difficult to discriminate. To address this problem, we propose a novel framework for temporal action proposal generation, namely Continuous Multi-stage Network (CMSN), which divides a video that contains a complete action instance into six stages, namely Backgroud, Ready, Start, Confirm, End, Follow. To distinguish between Ready and Start, End and Follow more accurately, we propose a novel loss function, Variable Margin Cosine Loss (VMCL), which allows for different margins between different categories. Our experiments on THUMOS14 show that the proposed method for temporal proposal generation performs better than the state-of-the-art methods using the same network architecture and training dataset.

Published
2019

25. Ultrasmall Polyphenol‐NAD+ Nanoparticle‐Mediated Renal Delivery for Mitochondrial Repair and Anti‐Inflammatory Treatment of AKI‐to‐CKD Progression

Author

Kong, Ying, primary, Chen, Xu, additional, Liu, Feng, additional, Tang, Jiageng, additional, Zhang, Yijing, additional, Zhang, Xiangxiang, additional, Zhang, Luyao, additional, Zhang, Tong, additional, Wang, Yaqi, additional, Su, Mengxiao, additional, Zhang, Qixin, additional, Chen, Hanxiang, additional, Zhou, Di, additional, Yi, Fan, additional, Liu, Hong, additional, and Fu, Yi, additional

Published
2024
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44. Inhibition of the CEBPβ-NFκB interaction by nanocarrier-packaged Carnosic acid ameliorates glia-mediated neuroinflammation and improves cognitive function in an Alzheimer’s disease model

Author

Wang Yi-Bin, Li Xiang, Yang Bing, Zhang Qi, Jiao Fei-Tong, Wang Minghong, Zhang Xiangxiang, Kang Le, Li Yan, Sui Ping, Gao Yufei, Xu Ye, and Wang Chun-Yan

Subjects
Cytology, QH573-671
Abstract

Abstract Neuroinflammation occurs early in Alzheimer’s disease (AD). The initial stage of AD is related to glial dysfunction, which contributes to impairment of Aβ clearance and disruption of synaptic connection. CEBPβ, a member of the CCAAT-enhancer-binding protein (CEBP) family, modulates the expression of inflammation-associated genes, and its expression is elevated in brains undergoing degeneration and injured brains. However, the mechanism underlying CEBPβ-mediated chronic inflammation in AD is unclear. In this study, we observed that increases in the levels of nuclear CEBPβ facilitated the interaction of CEBPβ with the NFκB p65 subunit, increasing the transcription of proinflammatory cytokines in the APP/PS1 mouse brain. Oral administration of nanocarrier-packaged carnosic acid (CA) reduced the aberrant activation of microglia and astrocytes and diminished mature IL-1β, TNFα and IL-6 production in the APP/PS1 mouse brain. CA administration reduced β-amyloid (Aβ) deposition and ameliorated cognitive impairment in APP/PS1 mice. We observed that CA blocked the interaction of CEBPβ with NFκB p65, and chromatin immunoprecipitation revealed that CA reduced the transcription of the NFκB target genes TNFα and IL-6. We confirmed that CA alleviated inflammatory mediator-induced neuronal degeneration and reduced Aβ secretion by inhibiting the CEBPβ-NFκB signalling pathway in vitro. Sulfobutyl ether-beta-cyclodextrin (SBEβCD) was used as the encapsulation agent for the CA-loaded nanocarrier to overcome the poor water solubility and enhance the brain bioavailability of CA. The CA nanoparticles (NPs) had no obvious toxicity. We demonstrated a feasible SBEβCD-based nanodelivery system targeting the brain. Our data provide experimental evidence that CA-loaded NPs are potential therapeutic agents for AD treatment.

Published
2022
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47. Functional Prototissues Using Artificial Cells as Building Blocks and Their Biomedical Applications.

Author

Zhang, Xiangxiang, Li, Chao, Yang, Boyu, Wang, Weichen, Zhao, Jingjing, Zhao, Wan, Dong, Mingdong, and Han, Xiaojun

Abstract

The construction of living systems from the bottom‐up helps to explore the complex processes of life and to understand their working mechanism. Prototissues, constructed using artificial cells as building blocks, mimic life systems at a high‐order tissue level, whilst artificial cells usually mimic living cells at the individual cell level. The 3D biomimetic prototissues demonstrate exceptional performances and collective functions, which reveal the working mechanisms of living tissues and hold promising potential for biomedical applications. This review systematically summarized the research progress of the field of prototissues. The engineering methods for fabricating two types of prototissues are introduced first, followed by the functions of prototissues including collective behaviors and signal communications, as well as their biomedical applications. The challenges and future trends are proposed at the end of the paper. [ABSTRACT FROM AUTHOR]

Published
2024
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