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The effect of NDGA-modified etchant on the enzymatic degradation resistance and mechanical properties of collagen matrix

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Chinese Chemical Letters 2018年第1期29卷 205-208页

作者： Shi-Qiang Gong zhen-jie xue Shu-Teng Liao Ya-Bo Wu Yan Liu Center of Stomatology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Beijing National Laboratory for Molecular Science Key Laboratory of Analytical Chemistry for Living Biosystems Institute of Chemistry the Chinese Academy of Sciences Laboratory of Biomimetic Nanomaterials Department of Orthodontics Peking University School and Hospital of Stomatology National Engineering Laboratory for Digital and Material Technology of Stomatology Beijing Key Laboratory of Digital Stomatology

Enzymatic degradation of demineralized collagen matrix seriously impairs durable resin-dentin bonding. In this study, we evaluated the effect of nordihydroguaiaretic acid （NDGA）-modified etchant on the resistance to enzymatic degradation and mechanical properties of demineralized collagen matrix. Dentin beams were randomly demineralized by following solutions： 1 ） 10% phosphoric acid （PhA） solution, 2） 10% dimethyl sulfoxide （DMSO）-PhA solution, 3） NDGA-modified etchant, and 4） proanthocyanidins （PA）-modified etchant. The demineralized dentin collagen was then digested by type l collagenase solution. The collagenase degradation resistance was evaluated by measuring loss of dry mass, hydroxyproline release, and elastic modulus change. The degradation rate and hydroxyproline release of dentin collagen treated with NDGA-modified etchant were significantly lower than those in the other groups （P〈 0.001）. The elastic modulus of dentin beams treated with NDGA-modified etchant did not increase significantly. However, after 48 h of collagenase degradation, the loss of elastic modulus of dentin beams treated with NDGA-modified etchant was significantly lower than that of the control group （P〈 0.001）. The NDGA-modified etchant could improve the resistance to enzymatic degradation of type l collagenase degradation, and the stability of the mechanical properties of dentin collagen. This proof-of-concept study validates the etch-and-crosslink technique that improves durability of dentin bonding through simultaneous dentin etching and collagen crosslinking.

关键词： NDGACrosslinkDegradationMechanical propertiesCollagen

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Climatic impacts induced by winter wheat irrigation over North China simulated by the nonhydrostatic RegCM4.7

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Advances in Climate Change Research 2024年第2期15卷 197-210页

作者： Jia WU zhen-Yu HAN xue-jie GAO zheng-Jia LIU National Climate Centre China Meteorological AdministrationBeijing 100081China Key Laboratory for Climate Studies China Meteorological AdministrationBeijing 100081China Climate Change Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China

Quantification of the impact of winter wheat irrigation on the climate and the occurrence of extreme climatic events over North China is crucial for regional adaptation *** related studies mainly focused on the impact on surface processes;however,few focused on the effects of extreme events using high-resolution nonhydrostatic regional climate ***,the 9-km-resolution nonhydrostatic RegCM4.7 was coupled with a crop irrigation scheme and an updated winter wheat irrigation dataset to better simulate irrigation *** experiments were conducted with and without winter wheat irrigation to isolate the effects of *** showed that irrigation simulation reduces the model biases in temperature,precipitation,latent heat flux,soil moisture,sensitive heat flux,and top-layer soil ***,it also reduces the bias and increases the correlation with observations obtained in irrigated areas,especially in summer,indicating better representation of irrigation *** wheat irrigation tends to cause substantial cooling of the local surface maximum,minimum,and mean air temperatures(by-1.68,-0.34,and-0.79℃,respectively)over irrigated areas of North China,with the largest changes observed in relation to maximum ***,precipitation is found to increase during spring and summer,which is strongly related to water vapor transport in the lower levels of the *** analyses indicated that the number of annual mean hot days decrease(-13.9 d),whereas the number of both comfort days(+10.2 d)and rainy days(days with total precipitation greater than 1 mm:+6.6 d)increase over irrigated areas,demonstrating beneficial feedback to human perception and ***,although the heat wave risk increases(number of annual mean heat wave days:+5.8 d),the impact is limited to small areas within irrigated ***,no notable change was found in terms of heavy rainfall events and precipitation intensity

关键词： Nonhydrostatic regional climate model Irrigation effect Extreme events North China

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Mechanical performance of 22SiMn2TiB steel welded with lowtransformation- temperature filler wire and stainless steel filler wire

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Journal of Iron and Steel Research International 2024年第4期31卷 967-981页

作者： Zi-dong Lin Kai-jie Song zhen Sun Zi-qian Zhu xue-feng Zhao Constantinos Goulas Wei Ya Xing-hua Yu School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China Department of Design Production and Management Faculty of Engineering Technology.University of TwenteEnschede 7500 AETheNetherlands Rotterdam Additive Manufacture Fieldlab(RAMLAB) Rotterdam 3089 JWTheNetherlands

TX-80 low-transformation-temperature(LTT)welding wire was used to replace the traditional ER 307Si welding wire to realize the connection of 22SiMn2TiB armor steel in manual overlay *** previously existing issues,such as welding cracks,large welding deformation,and severe welding residual stress,were solved to ensure good strength and ductility *** particular,with the same welding conditions,TX-80 LTT wire eliminates welding *** reduces the welding deformation no matter the base pretreatment of pre-setting angle or no pre-setting *** comparison,it was found that the microstructure at the TX-80 weld is mainly composed of martensite and a small amount of retained *** contrast,the microstructure of the ER 307Si weld consists of a large amount of austenite and a small amount of skeleton-like *** variation trend of residual stress and microhardness from the weld to the base were investigated and compared with the mechanical properties of base *** TX-80 and the ER 307Si tensile samples elongation is 6.76%and 6.01%,while the ultimate tensile strengths are 877 and 667 MPa,*** average impact toughness at room temperature of the ER 307Si weld is 143.9 J/cm^(2),much higher than that of the TX-80 weld,which is only 36.7 J/cm^(2).The relationship between impact and tensile properties with microstructure species and distribution was *** addition,the fracture surface of the tensile and the impact samples was observed and *** dimples,fewer pores,larger radiation zone,and shear lips of TX-80 samples indicate better tensile ductility and worse impact toughness than those of ER 307Si weld.

关键词： Low-transformation-temperature material 22SiMn2TiB steel Welding deformation Residual stress Martensitic transformation Mechanical property

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An interlaminar damage shell model for typical composite structures

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Chinese Journal of Aeronautics 2024年第1期37卷 118-137页

作者： jie ZHOU zhen WU zhengliang LIU Xiaohui REN School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China National Key Laboratory of Strength and Structural Integrity Xi’an 710065China School of Mechanical Engineering Xi’an Aeronautical UniversityXi’an 710065China

Using the plate/shell elements in commercial software,accurate analysis of interlaminar initial damage in typical composite structures is still a challenging *** propose an accurate and efficient model for analysis of interlaminar initial damage,the following work is carried out:(A)A higher-order theory is firstly proposed by introducing the local Legendre polynomials,and then a novel shell element containing initial damage prediction is developed,which can directly predict transverse shear stresses without any postprocessing *** variables at each node are independent of number of layers,so the proposed model is more efficient than the 3D-FEM.(B)Compression experiment is carried out to verify the capability of the proposed *** results obtained from the proposed model are in good agreement with experimental data.(C)Several examples have been analyzed to further assess the capability of the proposed model by comparing to the 3D-FEM ***,accuracy and efficiency have been evaluated in different damage criterion by comparing with the selected *** numerical results show that the proposed model can well predict the initial interlaminar damage as well as other ***,the model is implemented with UEL subroutine,so that the present approach can be readily utilized to analyze the initial damage in typical composite structures.

关键词： Compression experiment Finite element method Initial damage Interlaminar stress Plate/shell element

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Lactobacilli inhibit interleukin-8 production induced by Helicobacter pylori lipopolysaccharide-activated Toll-like receptor 4

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World Journal of Gastroenterology 2008年第32期14卷 5090-5095页

作者： Chao Zhou Feng-zhen Ma xue-jie Deng Hong Yuan Hong-Sheng Ma Department of Gastroenterology West China Hospital of Sichuan University Chengdu 610041 Sichuan Province China

AIM： To investigate the effect of Lactobacillus bulgaricus （LBG） on the Toll-like receptor 4 （TLR4） pathway and interleukin-8 （IL-8） production in SGC-7901 cells treated with Helicobacter pyloriSydney strain 1 lipopolysaccharide （HpyloriSS1-LPS）. METHODS： SGC-7901 cells were treated with HpyloriSS1-LPS in the presence or absence of pretreatment for 1 h with viable LBG or supernatant recovered from LBG culture MRS broth （LBG-s）. Cellular lysates were prepared for Western blot with anti-TLR4, anti-transforming growth factor β-activated kinase 1 （TAK1）, anti-phospho-TAK1, anti-nuclear factor κB （NF-κB）, anti-p38 mitogen-activated protein kinase （p38MAPK）, and anti-phospho-p38MAPK antibodies. The amount of IL-8 in cell culture medium was measured by ELISA. RESULTS： H pyloriSS1-LPS up-regulated the expression of TLR4, stimulated the phosphorylation of TAKI, subsequently enhanced the activation of NF- κB and the phosphorylation of p38MAPK in a time- dependent manner, leading to augmentation of IL-8 production in SGC-7901 cells. Viable LBG or LBG-s pretreatment attenuated the expression of TLR4, inhibited the phosphorylation of TAK1 and p38MAPK, prevented the activation of NF-κB, and consequently blocked IL-8 ***： H py/oriSS1-LPS induces IL-8 production through activating TLR4 signaling in SGC-7901 cells and viable LBG or LBG-s prevents H pyloriSS1-LPS-mediated IL-8 production via inhibition of the TLR4 pathway.

关键词： Lactobacillus Helicobacter pylori Lipopoly-saccharide Toll-like receptor 4, Interleukin-8

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Projected changes in Köppen-Trewartha climate zones under 1.5-4℃global warming targets over mid-high latitudes of Northern Asia using an ensemble of RegCM4 simulations

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Advances in Climate Change Research 2024年第2期15卷 185-196页

作者： jie WU xue-jie GAO Xian-Bing TANG Filippo GIORGI School of Geography and Environmental Engineering Gannan Normal UniversityGanzhou 341000China Climate Change Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing 210044China University of Chinese Academy of Sciences Beijing 100049China The Abdus Salam International Centre for Theoretical Physics Trieste 34100Italy

Mid-high latitude Northern Asia is one of the most vulnerable and sensitive areas to global warming,but relatively less studied *** used an ensemble of a regional climate model(RegCM4)projections to assess future changes in surface air temperature,precipitation and Köppen-Trewartha(K-T)climate types in Northern Asia under the 1.5-4℃global warming ***4 is driven by five CMIP5 global models over an East Asia domain at a grid spacing of 25 *** of the present day(1986-2005)simulations shows that the ensembles of RegCM4(ensR)and driving GCMs(ensG)reproduce the major characters of the observed temperature,precipitation and K-T climate zones reasonably *** and more realistic spatial detail is found in RegCM4 compared to the driving GCMs.A general warming and overall increases in precipitation are projected over the region,with these changes being more pronounced at higher warming *** projected warming by ensR shows different spatial patterns,and is in general lower,compared to ensG in most months of the year,while the percentage increases of precipitation are maximum during the cold *** future changes in K-T climate zones are characterized by a substantial expansion of Dc(temperature oceanic)and retreat of Ec(sub-arctic continental)over the region,reaching∼20%under the 4℃warming *** most notable change in climate types in ensR is found over Japan(∼60%),followed by Southern Siberia,Mongolia,and the Korean Peninsula(∼40%).The largest change in the K-T climate types is found when increasing from 2 to 3℃.The results will help to better assess the impacts of climate change and in implementation of appropriate adaptation measures over the region.

关键词： Mid-high latitudes of Northern Asia Köppen climate zones Global warming targets Regional climate model

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SG-NeRF:Sparse-Input Generalized Neural Radiance Fields for Novel View Synthesis

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Journal of Computer Science & Technology 2024年第4期39卷 785-797页

作者： Kuo Xu jie Li zhen-Qiang Li Yang-jie Cao School of Cyber Science and Engineering Zhengzhou UniversityZhengzhou 450002China Intelligent Big Data System(iBDSys)Lab Shanghai Jiao Tong UniversityShanghai 200240China School of Computer and Artificial Intelligence Zhengzhou UniversityZhengzhou 450001China

Traditional neural radiance fields for rendering novel views require intensive input images and pre-scene optimization,which limits their practical *** propose a generalization method to infer scenes from input images and perform high-quality rendering without pre-scene optimization named SG-NeRF(Sparse-Input Generalized Neural Radiance Fields).Firstly,we construct an improved multi-view stereo structure based on the convolutional attention and multi-level fusion mechanism to obtain the geometric features and appearance features of the scene from the sparse input images,and then these features are aggregated by multi-head attention as the input of the neural radiance *** strategy of utilizing neural radiance fields to decode scene features instead of mapping positions and orientations enables our method to perform cross-scene training as well as inference,thus enabling neural radiance fields to generalize for novel view synthesis on unseen *** tested the generalization ability on DTU dataset,and our PSNR(peak signal-to-noise ratio)improved by 3.14 compared with the baseline method under the same input *** addition,if the scene has dense input views available,the average PSNR can be improved by 1.04 through further refinement training in a short time,and a higher quality rendering effect can be obtained.

关键词： Neural Radiance Fields(NeRF) multi-view stereo(MVS) new view synthesis(NVS)

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Oxidation behavior of low-grade vanadiferous titanomagnetite concentrate with high titanium

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Journal of Iron and Steel Research International 2024年第2期31卷 329-341页

作者： Jin-sheng Liu zhen-xing Xing Gong-jin Cheng xue-yong Ding Xiang-xin xue School of Metallurgy Northeastern UniversityShenyang110819LiaoningChina Liaoning Key Laboratory of Recycling Science for Metallurgical Resources Shenyang110819LiaoningChina Innovation Research Institute of Vanadium and Titanium Resource Industry Technology Northeastern UniversityShenyang110819LiaoningChina

In order to clarify the oxidation mechanisms and make better use of the low-grade vanadiferous titanomagnetite concentrate with high titanium(LVTC),the oxidation behavior of LVTC was *** results showed that oxidation degree was achieved within 90 min when temperature was not lower than 700°C,and the main phases of the oxidized LVTC consisted of Fe9TiO15,Fe2O3,CaSiTiO5 and a small amount of *** temperature is favorable to the formation of *** surface of LVTC gradually becomes rough,with fine particles of needle-like and granular shape appearing on the surface,which finally turn from laminar to creamy,spread out,and are interspersed with many tiny *** phase oxidation paths in LVTC were as follows:(1)Fe2.75Ti0.25O4→Fe9TiO15+Fe2O3;(2)Fe2.75Ti0.25O4→Fe2O3+FeTiO3→Fe2TiO5;(3)FeTiO3→Fe2O3+Fe2Ti3O9→*** is predominantly mesoporous whether oxidized or not,with the pores mainly distributed in the range of 2–40 nm,and the specific surface area of LVTC decreases significantly with increasing temperature.

关键词： Low-grade vanadiferous titanomagnetite concentrate Oxidation degree Phase transformation Micromorphology Oxidation path Pore structure

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Sum-Rate Maximization in Active RIS-Assisted Multi-Antenna WPCN

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China Communications 2024年第6期21卷 23-39页

作者： Jiang jie Lyu Bin Chen Pengcheng Yang zhen School of Communications and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing 210003China Jiangsu Provincial Key Laboratory of Photonic and Electronic Materials Sciences and Technology Nanjing UniversityNanjing 210003China

In this paper,we propose an active reconfigurable intelligent surface(RIS)enabled hybrid relaying scheme for a multi-antenna wireless powered communication network(WPCN),where the active RIS is employed to assist both wireless energy transfer(WET)from the power station(PS)to energyconstrained users and wireless information transmission(WIT)from users to the receiving station(RS).For further performance enhancement,we propose to employ both transmit beamforming at the PS and receive beamforming at the *** formulate a sumrate maximization problem by jointly optimizing the RIS phase shifts and amplitude reflection coefficients for both the WET and the WIT,transmit and receive beamforming vectors,and network resource *** solve this non-convex problem,we propose an efficient alternating optimization algorithm with the linear minimum mean squared error criterion,semidefinite relaxation(SDR)and successive convex approximation ***,the tightness of applying the SDR is *** results demonstrate that our proposed scheme with 10 reflecting elements(REs)and 4 antennas can achieve 17.78%and 415.48%performance gains compared to the single-antenna scheme with 10 REs and passive RIS scheme with 100 REs,respectively.

关键词： active reconfigurable intelligent surface beamforming sum-rate maximization wireless powered communication network

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Assessment of climate damage in China based on integrated assessment framework

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Advances in Climate Change Research 2024年第1期15卷 124-133页

作者： jie LIU Xiang-zhen SHI Li YANG Chang-Yi LIU Jin-Cheng WANG Rui-Min ZHU xue-Li SHI Qiu-Feng LIU International Business School Shanxi Normal UniversityXi'an 710062China University of Chinese Academy of Social Sciences Bejing 102488China School of Economics and Management Xinjiang UniversityUrumqi 830046China Global Energy Interconnection Development and Cooperation Organization(GEIDCO) Bejing 100031China Hubei Enshi College Enshi 445099China CMA Earth System Modeling and Prediction Centre China Meteorological AdministrationBeijing 100081China National Climate Centre China Meteorological AdministrationBeijing 100081China

Developing a localized and consistent model framework for climate loss and damage assessment is crucial for the policy-making of climate change mitigation and *** study introduces a comprehensive,multidisciplinary Integrated Assessment Model(IAM)framework for evaluating climate damage in China,utilizing BCC-SESM climate model and FUND sectoral climate damage model under the SSP2-RCPs *** a bottom-up approach,the research estimates climate damage across eight major sectors,recalibrates sectoral climate damage functions and parameters for China,and elucidates distinctions among direct climate loss,market climate loss,and aggregate climate *** findings reveal that the total climate damage function for China follows a quadratic pattern in response to temperature *** 2050,the estimated climate damage is projected to be 5.4%,5.7%,and 8.2%of GDP under RCP2.6,RCP4.5,and RCP8.5,***,both direct and market climate losses are projected to remain below 2%of GDP by 2050,while the aggregate climate loss could reach as high as 8.2%,which is predominantly attributed to non-market *** a sectoral perspective,under the RCP8.5 scenario,human health damage constitutes the largest share(61.9%)of the total climate loss by 2050,followed by sea-level rise damage(18.6%).This study sheds lights on the adaptation policy that should attach importance to the non-market sectors,particularly focusing on human health and sea-level rise.

关键词： Climate loss and damage Integrated assessment model(IAM) FUND model Representative concentration pathways(RCPs)scenario BCC-SESM

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