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Curve Shortening Flow in Arbitrary Dimensional Euclidian Space

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Acta Mathematica Sinica,English Series 2005年第4期21卷 715-722页

作者： Yun Yan YANG xiao xiang jiao School of Mathematical Sciences Peking University Beijing 100871 P. R. China Graduate School Chinese Academy of Sciences P. R. China

In this paper, curve shortening flow in Euclidian space R^n（n≥3） is studied, and S. Altschuler＇s results about flow for space curves are generalized. We prove that the curve shortening flow converges to a straight line in infinite time if the initial curve is a ramp. We also prove the planar phenomenon when the curve shortening flow blows up.

关键词： Curve shortening flow Singularity formation Blow up

Development and validation of a nomogram model for predicting the risk of pre-hospital delay in patients with acute myocardial infarction

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World Journal of Cardiology 2024年第2期16卷 80-91页

作者： jiao-Yu Cao Li-xiang Zhang xiao-Juan Zhou Department of Cardiology The First Affiliated Hospital of USTCDivision of Life Science and MedicineUniversity of Science and Technology of ChinaHefei 230001Anhui ProvinceChina

BACKGROUND Acute myocardial infarction(AMI)is a severe cardiovascular disease caused by the blockage of coronary arteries that leads to ischemic necrosis of the *** medical contact is critical for successful AMI treatment,and delays increase the risk of death for ***-hospital delay time(PDT)is a significant challenge for reducing treatment times,as identifying high-risk patients with AMI remains *** study aims to construct a risk prediction model to identify high-risk patients and develop targeted strategies for effective and prompt care,ultimately reducing PDT and improving treatment *** To construct a nomogram model for forecasting pre-hospital delay(PHD)likelihood in patients with AMI and to assess the precision of the nomogram model in predicting PHD *** A retrospective cohort design was employed to investigate predictive factors for PHD in patients with AMI diagnosed between January 2022 and September *** study included 252 patients,with 180 randomly assigned to the development group and the remaining 72 to the validation group in a 7:3 *** risk factors influencing PHD were identified in the development group,leading to the establishment of a nomogram model for predicting PHD in patients with *** model's predictive performance was evaluated using the receiver operating characteristic curve in both the development and validation *** Independent risk factors for PHD in patients with AMI included living alone,hyperlipidemia,age,diabetes mellitus,and digestive system diseases(P<0.05).A characteristic curve analysis indicated area under the receiver operating characteristic curve values of 0.787(95%confidence interval:0.716–0.858)and 0.770(95%confidence interval:0.660-0.879)in the development and validation groups,respectively,demonstrating the model's good discriminatory *** Hosmer–Lemeshow goodness-of-fit test revealed no statistically significant disparity between the an

关键词： Pre-hospital delay Acute myocardial infarction Risk prediction Nomogram

Prediction of undeformed chip thickness distribution and surface roughness in ultrasonic vibration grinding of inner hole of bearings

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第4期25卷 311-323页

作者： Yanqin LI Daohui xiang Guofu GAO Feng jiao Bo ZHAO School of Mechanical and Power Engineering Henan Polytechnic UniversityJiaozuo 454000China

Ultrasonic vibration grinding differs from traditional grinding in terms of its material removal *** randomness of grain-workpiece interaction in ultrasonic vibration grinding can produce variable chips and impact the surface roughness of ***,previous studies used iterative method to calculate the unformed chip thickness(UCT),which has low computational *** this study,a symbolic difference method is proposed to calculate the *** UCT distributions are obtained to describe the stochastic interaction characteristics of ultrasonic grinding ***,the UCT distribution characteristics under different machining parameters are ***,a surface roughness prediction model is established based on the UCT ***,the correctness of the model is verified by *** study provides a quick and accurate method for predicting surface roughness in longitudinal ultrasonic vibration grinding.

关键词： Ultrasonic vibration grinding Undeformed chip thickness(UCT) Distribution characteristics Surface roughness

Sulfuretin exerts diversified functions in the processing of amyloid precursor protein

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Genes & Diseases 2021年第6期8卷 867-881页

作者： Jian Chen Biao Luo Bi-Rou Zhong Kun-Yi Li Qi-Xin Wen Li Song xiao-jiao xiang Gui-Feng Zhou Li-Tian Hu xiao-Juan Deng Yuan-Lin Ma Guo-Jun Chen Department of Neurology The First Affiliated Hospital of Chongqing Medical UniversityChongqing Key Laboratory of Neurology1 Youyi RoadChongqing400016PR China Department of Neurology Nanchong Central HospitalThe Second Clinical College of North Sichuan Medical CollegeNanchongSichuan Province637000PR China

Sulfuretin is a flavonoid that protects cell from damage induced by reactive oxygen species and *** this study,we investigated the role of sulfuretin in the processing of amyloid precursor protein(APP),in association with the two catalytic enzymes the a-secretase a disintegrin and metalloproteinase(ADAM10),and the beta-site APP cleaving enzyme 1(BACE1)that play important roles in the generation of β amyloid protein(Aβ)in Alzheimer’s disease(AD).We found that sulfuretin increased the levels of the immature but not the mature form of ADAM10 *** enhanced ADAM10 transcription by sulfuretin was mediated by the nucleotides444 to300 in the promoter region,and was attenuated by silencing or mutation of transcription factor retinoid X receptor(RXR)and by GW6471,a specific inhibitor of peroxisome proliferator-activated receptor α(PPAR-α).We further found that sulfuretin preferentially increased protein levels of the immature form of APP(im-APP)but significantly reduced those of BACE1,sAPPβ and β-CTF,whereas Ab1-42 levels were slightly ***,the effect of sulfuretin on BACE1 and im-APP was selectively attenuated by the translation inhibitor cycloheximide and by lysosomal inhibitor chloroquine,*** together,(1)RXR/PPAR-α signaling was involved in sulfuretin-mediated ADAM10 transcription.(2)Alteration of Aβ protein level by sulfuretin was not consistent with that of ADAM10 and BACE1 protein levels,but was consistent with the elevated level of im-APP protein,suggesting that im-APP,an isoform mainly localized to trans-Golgi network,plays an important role in Ab generation.

关键词： Ab ADAM10 BACE1 Immature APP RXR/PPAR-a Sulfuretin Trans-Golgi network

Three-dimensional porous bimetallic metal–organic framework/gelatin aerogels: A readily recyclable peroxymonosulfate activator for efficient and continuous organic dye removal

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Chinese Journal of Chemical Engineering 2024年第7期71卷 193-202页

作者： Wenlong xiang Xian Zhang Rou xiao Yanhui Zhang College of Chemistry Chemical Engineering and EnvironmentFujian Province Key Laboratory of Morden Analytical Science and Separation TechnologyMinnan Normal UniversityZhangzhou 363000China Fujian Provincial University Key Laboratory of Pollution Monitoring and Control Minnan Normal UniversityZhangzhou 363000China

As promising catalysts for the degradation of organic pollutants,metal–organic frameworks(MOFs)often face limitations due to the particle agglomeration and challenging recovery in liquid-catalysis application,stemming from their powdery *** macroscopic structures from pulverous MOF is thus of great importance for broadening their practical *** this study,three-dimensional porous MOF aerogel catalysts were successfully fabricated for degrading organic dyes by activating peroxymonosulfate(PMS).MOF/gelatin aerogel(MOF/GA)catalysts were prepared by directly integrating bimetallic FeCo-BDC with gelatin solutions,followed by freeze-drying and low-temperature *** FeCo-BDC-0.15/GA/PMS system exhibited remarkable performance in degrading various organic dyes,eliminating 99.2%of rhodamine B within a mere 5 *** to the GA/PMS system,there was over a 300-fold increase in the reaction rate ***,high removal efficiency was maintained across varying conditions,including different solution pH,co-existing inorganic anions,and natural water *** trapping experiments and electron paramagnetic resonance analysis revealed that the degradation involved radical(SO_(4)^(-)·)and non-radical routes(^(1)O_(2)),of which ^(1)O_(2) was ***,even after a continuous 400-min reaction in a fixed-bed reactor at a liquid hourly space velocity of 27 h^(-1),the FeCo-BDC/GA composite sustained a degradation efficiency exceeding 98.7%.This work presents highly active MOF-gelatin aerogels for dye degradation and expands the potential for their large-scale,continuous treatment application in organic dye wastewater management.

关键词： Catalyst Environment Wastewater Metal–organic framework Gelatin aerogel Peroxymonosulfate

Distortion-aware beamforming design for multi-beam satellite communications with nonlinear power amplifiers

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Science China(Information Sciences) 2024年第6期67卷 359-369页

作者： xiang xiao Li YOU Kezhi WANG Xiqi GAO National Mobile Communications Research Laboratory Southeast University Purple Mountain Laboratories Department of Computer Science Brunel University London

Hardware components can cause different impairments, including power amplifier(PA) nonlinearities, which inevitably impact the system performance of satellite communications(SATCOM). In this work, we consider a multi-beam SATCOM downlink system and investigate the distortion-aware beamforming scheme with the characteristics of PA non-linearities. Notably, we aim to maximize the resource efficiency(RE), defined as the weighted sum of energy efficiency(EE) with spectral efficiency(SE), to obtain a flexible EE-SE tradeoff while accounting for the characteristics of PA distortion and the total power *** that the optimization objective is a sum of ratios and the high non-convexity involved in constraints,we propose an efficient approach that exploits the quadratic transformation, the Lagrange multiplier method,and the gradient ascent approach to handle this issue. Simulation results demonstrate the effectiveness of the distortion-aware beamforming approach in achieving the EE-SE tradeoff and exhibit a substantial RE performance gain over the conventional approach with ideal linear PAs assumed at the satellite transmitters.

关键词： multi-beam satellite communications nonlinear power amplifier energy and spectral efficiency tradeoff resource efficiency robust beamforming

复格拉斯曼流形G(2,5)中的调和2-球面(英文)

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中国科学院研究生院学报 2011年第5期28卷 573-582页

作者：李康焦晓祥中国科学院研究生院数学科学学院北京100049

运用调和序列和活动标架研究复格拉斯曼流形G(2,5)中的调和2-球面.通过S2上全纯微分形式的构造,简化G(2,5)中沿调和2-球面的活动标架,并且给出高斯曲率的上界估计.

关键词：调和2-球面高斯曲率全纯微分形式调和序列

复格拉斯曼流形G(2,5)中的全纯2球(英文)

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中国科学院研究生院学报 2011年第2期28卷 131-140页

作者：费杰焦晓祥中国科学院研究生院数学科学学院北京100049

利用调和序列和活动标架研究了复格拉斯曼流形G(2,5)中线性满的全纯2球.利用SU(2)的不可约酉表示构造了G(2,5)中的一些齐性全纯2球.在U(5)等价意义下确定常高斯曲率为2/3和4/3的所有线性满的退化全纯2球.最后证明在某一特定条件下常高... 详细信息

利用调和序列和活动标架研究了复格拉斯曼流形G(2,5)中线性满的全纯2球.利用SU(2)的不可约酉表示构造了G(2,5)中的一些齐性全纯2球.在U(5)等价意义下确定常高斯曲率为2/3和4/3的所有线性满的退化全纯2球.最后证明在某一特定条件下常高斯曲率为4/3的非退化的全纯2球一定是U(5)等价的.

关键词：全纯2球高斯曲率复格拉斯曼流形调和序列

Increased Expression of Serum Monocyte Chemoattractant Protein-1,Chemokine(C-C motif)Ligand 3,and Interleukins in Patients With Vitiligo

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International Journal of Dermatology and Venereology 2024年第1期7卷 40-43页

作者： xiao-Ling Zhao Ya-Lan Li Zi-Han Li xiao-Chong Zhang Li-Hui An Yu-jiao Sun Deng-xiang Liu Fang Cheng Cancer Laboratory Xingtai People’s HospitalXingtaiHebei 054001China Endocrine Department Xingtai People’s HospitalXingtaiHebei 130500China Dermatological Department Xingtai People’s HospitalXingtaiHebei 054001China

Objective:Vitiligo is a chronic,acquired depigmentation of the skin,which can be divided into active and stable *** stable and active stages are not immutable and often *** of internal markers would help to diagnose the active stage of vitiligo,and the purpose of this study was to find potential active markers in the progression of ***:We compared 30 healthy controls to 60 patients with vitiligo(30 with active disease and 30 with stable disease)regarding the expression of serum monocyte chemoattractant protein(MCP)-1,chemokine(C-C motif)ligand(CCL)3,CCL5,CCL21,interleukin(IL)-6,and *** were collected from May 2017 to December *** detection was carried out by enzyme-linked immunosorbent *** difference between groups was compared by Kruskal-Wallis H test and Mann-Whitney U ***:We found that the serum levels of MCP-1,CCL3,IL-6,and IL-17 were significantly higher in patients with vitiligo than in healthy controls(P<0.01)and that IL-17 was higher in patients with active vitiligo than in those with stable vitiligo(P<0.01).After 3months of treatment,the serum IL-17 level of patients with active vitiligo was not significantly different from that before treatment(P=0.526);after 6months of treatment,however,the serum IL-17 level had significantly decreased(P<0.01).Conclusion:These findings suggest that the serum IL-17 level can be used as a marker of vitiligo disease activity giving it certain guiding significance for clinical treatment.

关键词： clinical marker serum cytokines vitiligo