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Human radiological safety assessment for petawatt laser-driven ion acceleration experiments in CLAPA-T

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Matter and Radiation at Extremes 2024年第4期9卷 8-15页

作者： Xiaopeng Zhang Jiarui Zhao Shengxuan Xu Xun Chen Ying Gao Shiyou Chen Kun Zhu Xueqing Yan wenjun Ma State Key Laboratory of Nuclear Physics and Technology and Key Laboratory of HEDP of the Ministry of EducationCAPTPeking UniversityBeijing 100871China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsCASBeijing 100049China Beijing Laser Acceleration Innovation Center HuairouBeijing 101400China Institute of Guangdong Laser Plasma Technology BaiyunGuangzhou 510540China

The newly built Compact Laser Plasma Accelerator-Therapy facility at Peking University will deliver 60 J/1 Hz laser pulses with 30 fs *** by this petawatt laser facility,proton beams with energy up to 200 MeV are expected to be generated for tumor *** high-repetition operation,both prompt radiation and residual radiation may cause safety ***,human radiological safety assessment before commissioning is *** this paper,we simulate both prompt and residual radiation using the Geant4 and FLUKA Monte Carlo codes with reasonable proton and as-produced electron beam *** find that the prompt radiation can be shielded well by the concrete wall of the experimental hall,but the risk from residual radiation is nonnegligible and necessitates adequate radiation *** the basis of the simulation results,we discuss the constraints imposed by radiation safety considerations on the annual working time,and we propose radiation cooling strategies for different shooting modes.

关键词： laser prompt acceleration

Enzymatic self-assembly/disassembly turns “ON”/“OFF” the mimetic hydrolytic activity of histidine nanofibers

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Science China Chemistry 2024年第2期67卷 517-522页

作者： Xianbao Sun Manli Wang Xiaoyang Liu wenjun Zhan Guangqiong Xu Qiaochu Jiang Hai-Dong Xu Fuqiang Wang Gaolin Liang State Key Laboratory of Digital Medical Engineering School of Biological Science and Medical EngineeringSoutheast UniversityNanjing210096China Analysis Center Nanjing Medical UniversityNanjing210029China

Mimetic enzymes are devised as alternates or supplements of natural enzymes in broad fields but regulating their activities in a switchable manner remains ***,we proposed an enzymatic self-assembly/disassembly strategy to address this issue.A peptide molecule Nap FFEYIH(YH) was rationally designed which,after self-assembling into nanofibers,lined up the histidine moieties to form active hydrolysis centers for mimicking hydrolase *** dephosphorylation of Nap FFEYp IH(Yp H) by alkaline phosphatase to yield YH also turned “ON” the hydrolase *** turn,phosphorylation of YH by phosphokinase epidermal growth factor receptor to yield Yp H disassembled the nanofibers and thus turned the activity “OFF”.As such,the “ON”/“OFF” of the mimetic hydrolase activities could be regulated under physiological conditions through ALP/EGFR-mediated self-assembly/disassembly of histidine *** work provides a feasible strategy for the on-demand fabrication of artificial enzymes with controllable and superior activities.

关键词： disassembly hydrolytic activity mimetic enzyme phosphorylation self-assembly

Endothelial phosphodiesterase 4B inactivation ameliorates endothelial-to-mesenchymal transition and pulmonary hypertension

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Acta Pharmaceutica Sinica B 2024年第4期14卷 1726-1741页

作者： Yanjiang Xing Yangfeng Hou Tianfei Fan Ran Gao Xiaohang Feng Bolun Li Junling Pang wenjun Guo Ting shu Jinqiu Li Jie Yang Qilong Mao Ya Luo Xianmei Qi Peiran Yang Chaoyang Liang Hongmei Zhao Wenhui Chen Jing Wang Chen Wang State Key Laboratory of Respiratory Health and Multimorbidity Institute of Basic Medical SciencesChinese Academy of Medical SciencesPeking Union Medical CollegeBeijing 100005China Department of Lung Transplantation National Center for Respiratory MedicineNational Clinical Research Center for Respiratory DiseasesChina–Japan Friendship HospitalInstitute of Respiratory MedicineChinese Academy of Medical SciencesBeijing 100029China Haihe Laboratory of Cell Ecosystem Chinese Academy of Medical Sciences and Peking Union Medical CollegeTianjin 300051China The State Key Laboratory of Complex Severeand Rare DiseasesInstitute of Basic Medical SciencesChinese Academy of Medical SciencesDepartment of PathophysiologyPeking Union Medical CollegeBeijing 100005China Department of Pharmacy West China HospitalSichuan UniversityChengdu 610044China

Pulmonary hypertension (PH) is a fatal disorder characterized by pulmonary vascular remodeling and obstruction. The phosphodiesterase 4 (PDE4) family hydrolyzes cyclic AMP (cAMP) and is comprised of four subtypes (PDE4A–D). Previous studies have shown the beneficial effects of pan-PDE4 inhibitors in rodent PH;however, this class of drugs is associated with side effects owing to the broad inhibition of all four PDE4 isozymes. Here, we demonstrate that PDE4B is the predominant PDE isozyme in lungs and that it was upregulated in rodent and human PH lung tissues. We also confirmed that PDE4B is mainly expressed in the lung endothelial cells (ECs). Evaluation of PH in Pde4b wild type and knockout mice confirmed that Pde4b is important for the vascular remodeling associated with PH. In vivo EC lineage tracing demonstrated that Pde4b induces PH development by driving endothelial-to-mesenchymal transition (EndMT), and mechanistic studies showed that Pde4b regulates EndMT by antagonizing the cAMP-dependent PKA–CREB–BMPRII axis. Finally, treating PH rats with a PDE4B-specific inhibitor validated that PDE4B inhibition has a significant pharmacological effect in the alleviation of PH. Collectively, our findings indicate a critical role for PDE4B in EndMT and PH, prompting further studies of PDE4B-specific inhibitors as a therapeutic strategy for PH.

关键词： Phosphodiesterase 4B Pulmonary hypertension Endothelial-to-mesenchymal transition

Bone tissue engineering scaffold materials: Fundamentals, advances, and challenges

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Chinese Chemical Letters 2024年第2期35卷 176-186页

作者： Chang Xu Zhize Liu Xi Chen Yang Gao wenjun Wang Xijing Zhuang Hao Zhang Xufeng Dong Department of Cardiovascular Surgery Central Hospital of Dalian University of TechnologyDalian 116089China School of Materials Science and Engineering Dalian University of TechnologyDalian 116024China Department of Orthopaedics Central Hospital of Dalian University of TechnologyDalian 116089China Department of Dermatology Allergologyand VenereologyUniversity of LübeckLübeck 23562Germany

Bone damage caused by trauma and tumors is a serious problem for human health, therefore, three-dimensional (3D) scaffolding materials that stimulate and promote the regeneration of broken bone tissues have become the focus of current research in the field of bone damage *** this regard, a preferential combination of materials and preparation techniques is considered crucial for the preparation of advanced bone tissue engineering scaffolds to better facilitate the regeneration of broken *** this review, current research advances and challenges in bone tissue engineering scaffolds are discussed and analyzed in ***, we elucidated the structure and self-healing mechanism of bone ***, the main applications of different materials, including inorganic and organic materials, in bone tissue engineering scaffolds are ***, we overview the latest research progress of the mainstream preparation strategies of bone tissue engineering scaffolds, and provide an in-depth analysis of the different advantages of each ***, promising future directions and challenges of bone tissue engineering scaffolds are systematically discussed.

关键词： Biomaterials Bone defects Tissue engineering Scaffolds Osteogenesis

Peroxidase-like active Cu-ZIF-8 with rich copper(I)-nitrogen sites for excellent antibacterial performances toward drug-resistant bacteria

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Nano Research 2024年第8期17卷 7427-7435页

作者： Xiaoze Wang Hui Wang Jingkun Zhang Ning Han wenjun Ma Donghai Zhang Mingshui Yao Xianliang Wang Yunfa Chen State Key Laboratory of Mesoscience and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of the Chinese Academy of Sciences Beijing 100049China Laboratory of Theoretical and Computational Nanoscience CAS Key Laboratory of Nanosystem and Hierarchial FabricationCAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China China CDC Key Laboratory of Environment and Population Health National Institute of Environmental HealthChinese Center for Disease Control and PreventionBeijing 100021China

Bacterial pathogens pose a serious threat to human health,and there is an urgent need to develop highly effective antibacterial materials to eliminate the increasingly serious contamination of drug-resistant ***,a Cu-doped ZIF-8 particle with unsaturated copper exhibits high peroxidase-like activity.99.998%antibacterial efficiency against *** can be achieved for 30 min at a low concentration of 50μg·mL^(−1),as well as complete sterilization against ***(up to 8 log).99.999%antibacterial efficiency against Methicillin-resistant Staphylococcus aureus can be achieved,performing orders of magnitude higher than *** mechanism shows that the unsaturated Cu-Nx sites are enzyme-like active centers,which could promote the consumption of bacteria reducing substances by H_(2)O_(2),and the generated*OH further aggravates bacterial oxidative stress and membrane *** importantly,the oxidation activity of adsorbed oxygen species on Cu-ZIF-8 is enhanced by charge transfer and structural changes between the ligand and copper center like natural ***-doped ZIF-8 with peroxidase-like activity shows great potential in antibacterial application and the revealed catalytic mechanism is helpful for understanding the high antibacterial activity of nanoparticles with Cu-Nx sites.

关键词： Cu-doped ZIF-8 peroxidase-like reactive oxygen species(ROS) catalytic mechanism antibacterial activity

Influence of sea-land breeze on the formation and dissipation of severe dense fog and its burst reinforcement in the Yellow Sea coastal area,China

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Science China Earth Sciences 2024年第2期67卷 432-449页

作者： Ya GAO Duanyang LIU shuqi YAN wenjun ZHOU Hongbin WANG Fan ZU Qin MEI Chuanxiang YI Ye SHENG Key Laboratory of Transportation Meteorology of China Meteorological Administration Nanjing210041China Yancheng Meteorological Bureau Yancheng224000China Nanjing Joint Institute for Atmospheric Sciences Nanjing210041China Key Laboratory of Disaster Weather Chinese Academy of Meteorological SciencesBeijing100086China

Based on the global reanalysis data of the National Centers for Environmental Prediction(NCEP)/National Center for Atmospheric Research,the surface meteorological observation data,sounding data and satellite observation data,this paper comprehensively analyzes the evolution process and formation mechanism of a persistent severe dense fog process occurred on February 15–17,2015 in Yancheng,eastern *** the numerical simulation experiment of Weather Research and Forecast(WRF)model,we further analyze the impact of sea-land breeze on the formation and burst reinforcement of *** show that the precipitation caused by the southwesterly airflow in front of the upper-level trough and the low-pressure inverted trough are conducive to the formation of early rain fog,while the nighttime clear radiance under the control of surface cold high and the infiltration of weak cold advection are conducive to the formation and development of later radiation-advection *** WRF model simulates the fog evolution process,which is basically consistent with the actual fog area,and the simulation results are credible to a certain *** simulation results show that the establishment of sea breeze has an advection cooling effect on the near surface layer,which is conducive to the formation and development of the inversion layer on the near surface,providing stable stratification conditions for the formation and burst reinforcement of *** one hand,the strengthening of sea breeze circulation can continuously transport water vapor to the study *** the other,the occurrence of ultra-low level jet is favorable for the accumulation of low-level water *** the same time,the inversion intensity further strengthens,which is in favor of the burst reinforcement and long-term maintenance of fog.

关键词： Radiation-advection fog Sea-land breeze Atmospheric boundary layer Fog burst reinforcement WRF model

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特长隧道斜井反井法综合施工技术研究

铁道建筑技术 2018年第2期 25-28,72页

作者：舒文军中铁十二局集团第三工程有限公司山西太原030024

二郎山隧道全长约13.4 km,是雅安至康定高速公路全线控制性工程。原设计斜井采用倒坡施工,通过方案优化,斜井采用反井法施工方案。文章结合二郎山隧道康定端斜井工程实例,介绍了斜井反井法施工过程开挖爆破、通风降尘、车辆行驶安全、... 详细信息

二郎山隧道全长约13.4 km,是雅安至康定高速公路全线控制性工程。原设计斜井采用倒坡施工,通过方案优化,斜井采用反井法施工方案。文章结合二郎山隧道康定端斜井工程实例,介绍了斜井反井法施工过程开挖爆破、通风降尘、车辆行驶安全、二衬施工的关键施工技术。该技术的采用,不仅保障了斜井施工进度与安全,同时节约了便道修建、临建施工及抽水费用,还极大的保护了二郎山脆弱的生态环境,为类似工程施工提供了新思路。

关键词：斜井反井法水幕降尘避险车道自行式台车

Hot Deformation Behavior of Ti-6Al-4V-0.5Ni-0.5Nb Titanium Alloy

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Journal of Wuhan University of Technology(Materials Science) 2024年第5期39卷 1270-1277页

作者： ZHU Guochuan LIU Qiang SONG Shengyin HUI Songxiao YU Yang YE wenjun QI Jun TANG Zhengwei XU Penghai CNPC Tubular Goods Research Institute Xi’an 710077China State Key Laboratory for Fabrication&Processing of Nonferrous Metals Beijing General Research Institute for Nonferrous MetalsBeijing 100088China China Petroleum Tarim Oilfield Company Korla 841000China

Characterization of hot deformation behavior of Ti-6Al-4V-0.5Ni-0.5Nb titanium alloy was investigated through isothermal compression at various temperatures from 750 to 1050℃and strain rate from 0.01 to 10 s^(-1).The isothermal compression experiment results showed that the peak stress of Ti-6Al-4V-0.5Ni-0.5Nb titanium alloy decreased with the temperature increasing and the strain rate *** softening mechanism was dynamic recovery below T_(β)and changed to dynamic recrystallization above T_(β).The arrheniustype relationship was used to calculate the constitutive equation of Ti-6Al-4V-0.5Ni-0.5Nb alloy in two-phase *** was found that the apparent activation energies were 427.095 kJ·mol^(-1)in theα+βphase region and 205.451 kJ·mol^(-1)in theβphase region,*** the basis of dynamic materials model,the processing map is generated,which shows that the highest peak efficiency of power dissipation of 56%occurs at about 1050℃/0.01 s^(-1).It can be found in the processing maps that the strain had significant effect on the peak region of power dissipation efficiency of Ti-6Al-4V-0.5Ni-0.5Nb ***,optimized hot working regions were investigated and validated through microstructure *** optimum thermo mechanical process condition for hot working of Ti-6Al-4V-0.5Ni-0.5Nb titanium alloy was suggested to be in the temperature range of 950-1000℃with a strain rate of 0.01-0.1 s^(-1).

关键词： titanium alloy hot deformation processing map dynamic recrystallization

Synthesis methods and powder quality of titanium monocarbide

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Chinese Journal of Chemical Engineering 2024年第08期 10-18页

作者： Maoqiao Xiang wenjun Ding Qinghua Dong Qingshan Zhu State Key Laboratory of Mesoscience and Engineering Institute of Process Engineering Chinese Academy of Sciences School of Chemical Engineering University of the Chinese Academy of Sciences Innovation Academy for Green Manufacture Chinese Academy of Sciences

Titanium monocarbide(TiC), which is the most stable titanium-based carbide, has attracted considerable interest in the fields of energy, catalysis, and structural materials due to its excellent properties. Synthesis of high-quality TiC powders with low cost and high efficiency is crucial for industrial applications;however major challenges face its realization. Herein, the methods for synthesizing TiC powders based on a reaction system are reviewed. This analysis is focused on the underlying mechanisms by which synthesis methods affect the quality of powders. Notably, strategies for improving the synthesis of highquality powders are analyzed from the perspective of enhancing heat and mass transfer ***, the critical issues, challenges, and development trends of the synthesis technology and application of high-quality TiC powder are discussed.

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来源：博看期刊