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Dammarane-type triterpenoids from Gynostemma longipes and their protective activities on hypoxia-induced injury in PC12 cells

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Chinese Journal of Natural Medicines 2024年第5期22卷 466-480页

作者： LIANG Haizhen CHEN Xiaojuan LI Qi zhang Mengmeng LU Pengxin zhang Jie SONG Juan zhang tao GUO Baolin MA Baiping Department of Pharmaceutical Sciences Beijing Institute of Radiation MedicineBeijing 100850China Institute of Medicinal Plant Development Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100193China AnKang Chia Tai Pharmaceutical Co. Ltd.Shaanxi 725000China

Sixteen new dammarane-type triterpenoid saponins(1-16)featuring diverse structural variations in the side chain at C-17,along with twenty-one known analogues(17-37),have been isolated from the rhizomes of Gynostemma longipes C.Y.Wu,a plant renowned for its medicinal and edible properties.The structural elucidation of these compounds was accomplished through comprehensive analyses of 1D and 2D NMR and HRMS spectroscopic data,supplemented by comparison with previously reported data.Subsequent assays on the isolates for their protective effects against hypoxia-induced damage in pheochromocytoma cells(PC12 cells)revealed that nine saponins exhibited significant anti-hypoxic activities.Further investigation into the anti-hypoxia mechanisms of the representative saponins demonstrated that compounds 22 and 36 markedly reduced the levels of hypoxia-induced apoptosis.Additionally,these compounds were found to decrease the release of lactate dehydrogenase(LDH)and malondialdehyde(MDA),while increasing the activity of superoxide dismutase(SOD),thereby indicating that the saponins could mitigate hypoxia-induced injuries by ameliorating apoptosis and oxidative stress.These findings offer substantial evidence for the future utilization and development of G.longipes,identifying dammarane-type triterpenoid saponins as its active anti-hypoxic constituents.

关键词： Gynostemma longipes Dammarane-type saponins Anti-hypoxia effect Apoptosis

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Non-Blind Image Deblurring via Shear Total Variation Norm

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Wuhan University Journal of Natural Sciences 2024年第3期 219-227页

作者： LI Weiyu zhang tao GAO Qiuli School of Microelectronics and Data Science Anhui University of Technology

In this paper, we propose a novel shear gradient operator by combining the shear and gradient operators. The shear gradient operator performs well to capture diverse directional information in the image gradient domain. Based on the shear gradient operator, we extend the total variation(TV) norm to the shear total variation(STV) norm by adding two shear gradient terms. Subsequently, we introduce a shear total variation deblurring model. Experimental results are provided to validate the ability of the STV norm to capture the detailed information. Leveraging the Block Circulant with Circulant Blocks(BCCB) structure of the shear gradient matrices, the alternating direction method of multipliers(ADMM) algorithm can be used to solve the proposed model efficiently. Numerous experiments are presented to verify the performance of our algorithm for non-blind image deblurring.

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Diversity and interactions of lichen mycobionts and photobionts in the Fildes Region, King George Island,maritime Antarctica

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Advances in Polar Science 2024年

作者： ZHU Yuwen YU Liyan zhang tao China Pharmaceutical Culture Collection Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences &Peking Union Medical College

Lichens, as dual organisms comprising a major mycobiont and a major photobiont, exhibit remarkable survival capabilities in extreme conditions, such as those found in Antarctica. Despite their adaptability, the diversity and distribution of lichen photobionts in the ice-free areas of maritime Antarctica remain less understood compared to their mycobiont counterparts.In our study, we investigated the diversity of both lichen mycobionts and photobionts in 56 samples collected from the Fildes Region on King George Island, maritime Antarctica. Through sequencing of the nuclear ribosomal internal transcribed spacer regions and subsequent phylogenetic analysis, we examined the relationships and association patterns between mycobionts and photobionts. Our findings revealed 19 taxa of lichen mycobionts across 13 families and seven orders, along with nine photobiont species within the class Trebouxiophyceae. These photobionts encompassed six Trebouxia species, one Asterochloris species,one Chloroidium species, and one Stichococcus species. In particular, a new Trebouxia lineage(Trebouxia sp. OTU D08) and a new Chloroidium lineage were found. The analysis indicated that many mycobionts could be associated with multiple photobiont species, a pattern also observed among the photobionts. These results contribute significantly to our understanding of the complex diversity of lichen mycobionts and photobionts in the ice-free areas of maritime Antarctica.

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Rational design of robust and transparent superrepellent surfaces for long-term marine antifouling

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Science China Technological Sciences 2024年第7期67卷 2031-2039页

作者： CHEN Hui WANG Zhi WANG DaHeng XIAO Feng FU Guang-En BU XueLing ZHAO Lei zhang tao WU DaHeng PU JiBin The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science & Technology Key Laboratory of Advanced Marine Materials Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences

Superhydrophobic surfaces have demonstrated exceptional efficacy in combatting biofouling contaminations of optical devices and equipment in marine applications. However, the fabrication of highly transparent superhydrophobic materials remains a formidable challenge due to the inherent trade-off between surface roughness for superhydrophobicity and optical transparency.Herein, we design a robust and transparent superhydrophobic coating(Si-POSS) embedded silica nanoparticles(200 nm) with fluorinated polyhedral oligomeric silsesquioxanes(F-POSS) and zinc pyrithione(ZPT). The Si-POSS coating exhibits excellent water repellence toward diverse liquids and optical transmittance exceeding 90% in the visible spectrum. Moreover, the Si-POSS coating sustains long-term anti-bacterial(> 99.11%) and anti-algal effects for over 30 days, accompanied by mechanical,chemical, and thermal stability. This research asserts that the Si-POSS coating with outstanding combined characteristics holds significant potential for marine applications, particularly in self-cleaning and antifouling endeavors.

关键词： superhydrophobic surface transparent marine antifouling nanoparticles

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Representation strategy for unsupervised domain adaptation on person re-identification

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Optoelectronics Letters 2024年

作者： LI Hao zhang tao LI Shuang LI Xuan ZHAO Xin College of Automotive Engineering Tianjin Vocational Institute School of Electrical and Information Engineering Tianjin University School of Electrical Engineering and Automation Tianjin University of Technology

The task of unsupervised person re-identification (Re-ID) is to transfer the knowledge learned in the source domain with no labels to the target domain with no labels. Due to the significant differences in the background of different datasets， the trained model is challenging to extract person features accurately on unsupervised domain adaptive (UDA). Most UDA methods for person re-ID use single-image representation (SIR) during the feature extraction. These methods might ignore the difference among the cross-view images with the same identity. For this problem， the Joint Learning Image Representation Strategy for Unsupervised Domain Adaptation (JLIRS-UDA)， which takes cross-image representation (CIR) into account for UDA， is proposed. The network architecture of JLIRS-UDA consists of two networks with branching networks. Each network consists of a shared network and two branching networks the SIR branch and CIR branch. The two branching networks aim to learn the SIR and CIR， respectively. To ensure the accuracy of the pseudo-label generation， the Segmenting Dynamic Clustering (SDC) method， which divides the training process into two phases， is proposed. Precisely， in the first phases， SDC adopts the single image features in the clustering phase to ensure that accurate feature details can be learned. In the second phase， SDC fuses SIR and CIR as the final feature for clustering to interactively promote the SIR branch and CIR branch. JLIRS-UDA learns the SIR and CIR jointly in the UDA task training phase. Compared with state-of-the-arts， the strategy proposed in this paper has achieved a significant improvement of 7.1% mAP on the tasks of Market-1501 to DukeMTMC-reID. The slightest improvement in accuracy also achieved +0.8% on Market-1501 to MSMT17..

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Pre-combustion mercury removal with co-production of hydrogen via coal electrolysis

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Journal of Environmental Sciences 2024年第2期136卷 382-389页

作者： Xiang Lyu Runming tao Tianyu zhang Chemical and Biomolecular Engineering Department Ohio University165 Stocker CenterAthensOH45701USA Electrification and Energy Infrastructures Division Oak Ridge National LaboratoryOak RidgeTN37831USA Beijing Key Lab for Source Control Technology of Water Pollution College of Environmental Science and EngineeringBeijing Forestry UniversityBeijing 100083China Engineering Research Center for Water Pollution Source Control&Eco-remediation College of Environmental Science and EngineeringBeijing Forestry UniversityBeijing 100083China

Pre-combustion mercury removal via coal electrolysis was performed and investigated on a bench-scale coal electrolytic cell(CEC)systemically,and factorial design was used to determine the effect of different operating conditions(coal particle size,operating temperature,operating cell voltage,and flow rate of slurry)on the percentage of mercury removal,percentage of ash removal,and dry heating value change.The results showed that the operating cell voltage,as well as the interaction between operating cell voltage and coal particle size,are significant factors in the percentage of mercury removal.There is no significant factor in the percentage of ash removal and the dry heating value change,but the coal could be purified while keeping the dry heating value almost constant after electrolysis.A co-product of hydrogen could be produced during coal electrolysis with 50%lower energy consumption compared with water electrolysis.Meanwhile,a mechanism for mercury removal in coal was proposed.The facts indicate that coal electrolysis is a promising method for precombustion mercury removal.

关键词： Pre-combustion mercury removal Coal electrolysis Ash removal Dry heating value Hydrogen production

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Deep Guided Attention Network for Joint Denoising and Demosaicing in Real Image

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Chinese Journal of Electronics 2024年第1期33卷 303-312页

作者： tao zhang Ying FU Jun zhang School of Computer Science and Technology Beijing Institute of Technology Advanced Reasearch Institute of Multidisciplinary Science Beijing Institute of Technology

Denoising(DN) and demosaicing(DM) are the first crucial stages in the image signal processing pipeline. Recently, researches pay more attention to solve DN and DM in a joint manner, which is an extremely undetermined inverse problem. Existing deep learning methods learn the desired prior on synthetic dataset, which limits the generalization of learned network to the real world data. Moreover, existing methods mainly focus on the raw data property of high green information sampling rate for DM, but occasionally exploit the high intensity and signalto-noise(SNR) of green channel. In this work, a deep guided attention network(DGAN) is presented for real image joint DN and DM(JDD), which considers both high SNR and high sampling rate of green information for DN and DM, respectively. To ease the training and fully exploit the data property of green channel, we first train DN and DM sub-networks sequentially and then learn them jointly, which can alleviate the error accumulation. Besides, in order to support the real image JDD, we collect paired raw clean RGB and noisy mosaic images to conduct a realistic dataset. The experimental results on real JDD dataset show the presented approach performs better than the state-of-the-art methods, in terms of both quantitative metrics and qualitative visualization.

关键词： Image denoising Image demosaicing Joint processing Guided attention Paired real dataset

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H?lder continuous weak solutions of the 2D Boussinesq equation with thermal diffusion

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Science China Mathematics 2024年第8期67卷 1777-1806页

作者： Tianwen Luo tao tao Liqun zhang Yau Mathematical Sciences Center Tsinghua University School of Mathematics Shandong University Institute of Mathematics Academy of Mathematics and Systems ScienceChinese Academy of Sciences School of Mathematical Sciences University of Chinese Academy of Sciences

We show the existence of H?lder continuous periodic weak solutions of the 2D Boussinesq equation with thermal diffusion which satisfy the prescribed kinetic energy. More precisely, for any smooth e(t):[0, 1]→■ and ... 详细信息

关键词： 2D Boussinesq equation with thermal diffusion Hölder continuous periodic weak solutions prescribed kinetic energy

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Securing multi-chain consensus against diverse miner behavior attacks in blockchain networks

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Frontiers of Information Technology & Electronic Engineering 2024年第4期25卷 540-554页

作者： Wenbo zhang tao WANG Chaoyang zhang Jingyu FENG School of Cyberspace Security Xi’an University of Posts and TelecommunicationsXi’an 710121China Postal Savings Bank of China Xi’an 710000China

As cross-chain technologies enable interactions among different blockchains(hereinafter“chains”),multi-chain consensus is becoming increasingly important in blockchain networks.However,more attention has been paid to single-chain consensus schemes.Multi-chain consensus schemes with trusted miner participation have not been considered,thus offering opportunities for malicious users to launch diverse miner behavior(DMB)attacks on different chains.DMB attackers can be friendly in the consensus process on some chains,called mask chains,to enhance their trust value,while on others,called kill chains,they engage in destructive behaviors on the network.In this paper,we propose a multi-chain consensus scheme named Proof-of-DiscTrust(PoDT)to defend against DMB attacks.The idea of distinctive trust(DiscTrust)is introduced to evaluate the trust value of each user across different chains.The trustworthiness of a user is split into local and global trust values.A dynamic behavior prediction scheme is designed to enforce DiscTrust to prevent an intensive DMB attacker from maintaining strong trust by alternately creating true or false blocks on the kill chain.Three trusted miner selection algorithms for multi-chain environments can be implemented to select network miners,chain miners,and chain miner leaders,separately.Simulation results show that PoDT is secure against DMB attacks and more effective than traditional consensus schemes in multi-chain environments.

关键词： Blockchain Cross-chain Trust mechanism Multi-chain consensus

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B cell development and antibody responses in human immune system mice:current status and future perspective

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Science China(Life Sciences) 2024年第4期67卷 645-652页

作者： tao zhang Wentao Liu Yong-Guang Yang Key Laboratory of Organ Regeneration&Transplantation of the Ministry of Education The First Hospital of Jilin UniversityChangchun 130061China National-Local Joint Engineering Laboratory of Animal Models for Human Diseases Jilin UniversityChangchun 130061China International Center of Future Science Jilin UniversityChangchun 130061China

Humanized immune system(HIS)mice have been developed and used as a small surrogate model to study human immune function under normal or disease conditions.Although variations are found between models,most HIS mice show robust human T cell responses.However,there has been unsuccessful in constructing HIS mice that produce high-affinity human antibodies,primarily due to defects in terminal B cell differentiation,antibody affinity maturation,and development of primary follicles and germinal centers.In this review,we elaborate on the current knowledge about and previous attempts to improve human B cell development in HIS mice,and propose a potential strategy for constructing HIS mice with improved humoral immunity by transplantation of human follicular dendritic cells(FDCs)to facilitate the development of secondary follicles.

关键词： humanized immune system mouse humoral immunity germinal center B cell follicular dendritic cell

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