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Alkyl Radical Initiated Cyclization/Cascade for Synthesizing Lactam-Substituted Alkyl Sulfones

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Chinese Journal of Chemistry 2024年第16期42卷 1853-1859页

作者： Li-Jun Wu Kai-Yi Zhang Pei Yang Chuan-Chong peng Jin-Hui Liu Qing Li Da-zhi Sun Shuangfeng Yin College of Sciences Central South University of Forestry and TechnologyChangshaHunan410004 China School of Chemistry and Chemical Engineering Inner Mongolia UniversityHohhotInner Mongolia010021 China

An alkyl radical initiated cyclization/tandem reaction of alkyl bromides and alkyl electrophiles by using potassium metabisulphite(K_(2.S_(2.O_(5))as a connector is developed for the synthesis of various lactam-substituted alkyl ***,this process does not require a metal catalyst or metal powder reductant,highlighting its environmentally friendly *** reaction demonstrates outstanding substrate adaptability and a high tolerance towards diverse functional ***,the biologically active molecules and commercially available drugs with a late-stage modification are also highly compatible with this *** studies revealed that the reaction proceeds through a single-step process involving intramolecular radical cyclization,"SO_(2."insertion,and external alkyl incorporation.

关键词： Alkyl radical Metal-free catalyzed Cyclization/cascade Potassium metabisulphite Electrophiles Alkyl sulfones Lactams Alkyl bromides Sodium formate

High-density lipoprotein regulates angiogenesis by affecting autophagy via miRNA-181a-5p

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Science China(Life Sciences) 2024年第2期67卷 286-300页

作者： Bi-Ang Kang Hua-Ming Li Ya-Ting Chen Meng-Jie Deng Yan Li Yue-Ming peng Jian-Jun Gao zhi-Wei Mo Jia-Guo Zhou zhi-Jun Ou Jing-Song Ou Division of Cardiac Surgery Cardiovascular Diseases InstituteThe First Affiliated HospitalSun Yat-sen UniversityGuangzhou 510080China National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases Guangzhou 510080China NHC key Laboratory of Assisted Circulation(Sun Yat-sen University) Guangzhou 510080China Guangdong Provincial Engineering and Technology Center for Diagnosis and Treatment of Vascular Diseases Guangzhou 510080China Division of Vascular Surgery The First Affiliated HospitalSun Yat-sen UniversityGuangzhou 510080China Department of Pharmacology Cardiac and Cerebral Vascular Research CenterZhongshan School of MedicineSun Yat-sen UniversityGuangzhou 510080China Division of Hypertension and Vascular Diseases Department of CardiologyCardiovascular Diseases InstituteThe First Affiliated HospitalSun Yat-sen UniversityGuangzhou 510080China Guangdong Provincial Key Laboratory of Brain Function and Disease Zhongshan School of MedicineSun Yat-sen UniversityGuangzhou 510080China

We previously demonstrated that normal high-density lipoprotein(nHDL)can promote angiogenesis,whereas HDL from patients with coronary artery disease(d HDL)is dysfunctional and impairs *** plays a critical role in angiogenesis,and HDL regulates ***,it is unclear whether n HDL and d HDL regulate angiogenesis by affecting *** cells(ECs)were treated with n HDL and d HDL with or without an autophagy ***,endothelial nitric oxide synthase(e NOS)expression,miRNA expression,nitric oxide(NO)production,superoxide anion(O2.(·-))generation,EC migration,and tube formation were evaluated.n HDL suppressed the expression of miR-181a-5p,which promotes autophagy and the expression of e NOS,resulting in NO production and the inhibition of O2.(·-)generation,and ultimately increasing in EC migration and tube formation.d HDL showed opposite effects compared to n HDL and ultimately inhibited EC migration and tube *** found that autophagy-related protein 5(ATG5)was a direct target of ***5 silencing or miR-181a-5p mimic inhibited n HDL-induced autophagy,e NOS expression,NO production,EC migration,tube formation,and enhanced O2.(·-)generation,whereas overexpression of ATG5 or miR-181a-5p inhibitor reversed the above effects of d ***5 expression and angiogenesis were decreased in the ischemic lower limbs of hypercholesterolemic low-density lipoprotein receptor null(LDLr^(-/-))mice when compared to C57BL/6 ***5 overexpression improved angiogenesis in ischemic hypercholesterolemic LDLr^(-/-)*** together,nHDL was able to stimulate autophagy by suppressing miR-181a-5p,subsequently increasing e NOS expression,which generated NO and promoted *** contrast,d HDL inhibited angiogenesis,at least partially,by increasing miR-181a-5p expression,which decreased autophagy and e NOS expression,resulting in a decrease in NO production and an increase in O2.(·-)*** findings reveal a nov

关键词： high-density lipoprotein angiogenesis autophagy ATG5 miRNA endothelial nitric oxide synthase

Mixed Dead-time Effect Suppression Strategy for Modular Multilevel Converters

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1075-1084页

作者： zhi Geng Minxiao Han School of Electrical and Electronic Engineering North China Electric Power UniversityBeijing 102206China IEEE

Dead time is necessary for the coupled power switches to prevent shoot-through,especially in the modular multilevel converters(MMCs)with a large number of power *** paper proposes a dead-time effect suppression strategy for MMCs with nearest level *** operational principles of MMCs are first *** to the operational features of MMCs,the method that removes a switching signal from the coupled switches and the reduced switching frequency voltage balancing algorithms(RSFVBAs)are mixed in the proposed *** the intervals that are furthest away from the zerocrossing points(ZCP)of arm currents,the single switching signal method can completely eliminate the dead-time effect(DTE).Alternatively,the DTE is suppressed by the RSFVBA in intervals that are close to the *** the combination of the two methods,the dependence of the DTE suppression method on currents is reduced and the influences of ZCP are also released without degrading the normal operation performance of ***,the output performance of MMCs is improved and the voltage stress on the arm inductor dramatically ***,the validation of the method is verified by the simulation results with the professional tool Matlab/Simulink.

关键词： Dead-time effect modular multilevel converters switching frequency voltage balancing algorithm

Isotopic dependence of the yield ratios of light fragments from different projectiles and their unified neutron skin thicknesses

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Nuclear Science and Techniques 2024年第3期35卷 228-236页

作者： Ting-zhi Yan Shan Li School of Energy and Power Engineering Northeast Electric Power UniversityJilin 132012China

The yield ratios of neutron-proton(R(n/p))and^(3)H-^(3)He(R(^(3)H∕^(3)He))with reduced rapidity from 0 to 0.5 were simulated at 50 MeV/u even-even ^(36−56)Ca+^(40)Ca,even-even ^(48−78)Ni+^(58)Ni,and ^(100−139)Sn(every third isotopes)+112.Sn for full reduced impact parameters using the isospin-dependent quantum molecular dynamics(IQMD)*** neutron and proton density distributions and root-mean-square radii of the reaction systems were obtained using the Skyrme-Hartree-Fock model,which was used for the phase space initialization of the projectile and target in *** defined the unified neutron skin thickness asΔRnp=2.>^(1∕2. n−2.>^(1∕2.p,which was negative for neutron-deficient *** unifiedΔRnp values for nuclei with the same relative neutron excess from different isotopic chains were nearly equal,except for extreme neutron-rich isotopes,which is a type of scaling *** yield ratios of the three isotopic chain-induced reactions,which depended on the reduced impact parameter and unified neutron skin thickness,were *** results showed that both R(n/p)and R(^(3)H∕^(3)He)decreased with a reduced impact parameter for extreme neutron-deficient isotopes;however,they increased with reduced impact parameters for extreme neutron-rich isotopes,and increased with theΔRnp of the projectiles for all reduced impact *** addition,a scaling phenomenon was observed betweenΔR np and the yield ratios in peripheral colli-sions from different isotopic chain projectiles(except for extreme neutron-rich isotopes).Thus,R(n/p)and R(^(3)H∕^(3)He)from peripheral collisions were suggested as experimental probes for extracting the neutron or proton skin thicknesses of non-extreme neutron-rich nuclei from different isotopic chains.

关键词： Exotic nuclei Unified neutron skin thickness Yield ratios IQMD

Clinicopathological analysis of small intestinal metastasis from extra-abdominal/extra-pelvic malignancy

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World Journal of Gastrointestinal Oncology 2024年第10期16卷 4138-4145页

作者： zhi Zhang Jing Liu peng-Fei Yu Hai-Rui Yang Jin-Yang Li zhi-Wei Dong Wei Shi Guo-Li Gu Department of General Surgery Anhui Medical University First Affiliated HospitalHefei 230002Anhui ProvinceChina Department of General Surgery Air Force Clinical CollegeChina Medical UniversityBeijing 100142China Department of General Surgery Air Force Medical CenterAir Force Clinical College of China Medical UniversityBeijing 100142China Department of General Surgery Air Force Medical CenterChinese People’s Liberation ArmyFifth Clinical(Air Force Clinical College)of China Medical UniversityBeijing 100142China Department of General Surgery Beijing Changping HospitalBeijing 102200China Department of General Surgery Air Force Medical CenterBeijing 100142China

BACKGROUND The metastatic tumors in the small intestine secondary to extra-abdominal/extrapelvic malignancy are extremely ***,the small intestine metastases are extremely prone to misdiagnosis and missed diagnosis due to the lack of specific clinical manifestations and examination methods,thus delaying its ***,in order to improve clinical diagnosis and treatment capabilities,it is necessary to summarize its clinical pathological characteristics and *** To summarize the clinicopathological characteristics of patients with small intestinal metastases from extra-abdominal/extra-pelvic malignancy,and to improve the clinical capability of diagnosis and treatment for rare metastatic tumors in the small *** The clinical data of patients with small intestinal metastases from extra-abdominal/extra-pelvic malignancy were retrieved and summarized,who admitted to and treated in the Air Force Medical Center,Chinese People’s Liberation *** descriptive statistics were performed on the general conditions,primary tumors,secondary tumors in the small intestine,diagnosis and treatment processes,and *** Totally 11 patients(9 males and 2.females)were enrolled in this study,including 8 cases(72.3%)of primary lung cancer,1 case(9.1%)of malignant lymphoma of the thyroid,1 case(9.1%)of cutaneous malignant melanoma,and 1 case(9.1%)of testicular *** median age at the diagnosis of primary tumors was 57.9 years old,the median age at the diagnosis of metastatic tumors in the small intestine was 58.81 years old,and the average duration from initial diagnosis of primary tumors to definite diagnosis of small intestinal metastases was 9 months(0-36 months).Moreover,small intestinal metastases was identified at the diagnosis of primary tumors in 4 *** small intestinal metastases were distributed in the jejunum and ileum,with such clinical manifestations as hematochezia(5,45.4%)and abdominal pain,vomiting and other obstr

关键词： Small intestinal Metastases Clinicopathological features Prognostic analysis Malignancy

Microstructures and mechanical properties of laser-directed energy deposited CrCoNi medium-entropy alloy

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Rare Metals 2024年第7期43卷 3286-3300页

作者： Wen-Jie Zhao Chang-Yu Liu peng-Cheng Che zhi-Liang Ning Hong-Bo Fan Jian-Fei Sun Yong-Jiang Huang Alfonso H.W.Ngan National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001China Space Environment Simulation Research Infrastructure Harbin Institute of TechnologyHarbin 150001China Department of Mechanical Engineering The University of Hong KongHong Kong 999077China

The distinctive intrinsic heat treatment(IHT)originating from cyclic reheating in the laser-directed energy deposition(LDED) has attracted growing attention in recent *** this investigation,simulations and experimental characterizations were performed to examine the impact of IHT on the micros true ture and mechanical properties of LDED-fabricated CrCoNi medium-entropy alloy(MEA).The results show that the intensity of the IHT is proportional to the utilized laser energy density(LED).As the LED increased,significant dynamic recrystallization and grain refinement occurred within the alloy due to the enhanced intensity of ***,the high LED leads to severe hot cracking within the as-built MEA,resulting in inferior *** decreasing LED,the hot cracking was effectively ***,low LED weakened the intensity of IHT and consequently inhibited kinetic conditions of dynamic recrystallization,resulting in a heterogeneous grain structure characterized by multi-scale-sized *** structure provides significant hetero-deformation-induced hardening during plastic deformation,enabling the alloy to have a sustainable work-hardening *** expect that this work will have implications in taking full advantage of the unique IHT of the LDED process to fabricate ME As with excellent metallurgical quality and mechanical performance.

关键词： Intrinsic heat treatment Laser-directed energy deposition CrCoNi MEA Dynamic recrystallization Heterogeneous grain structure

Thermal and mechanical behavior of casting copper alloy wheel during wheel and belt continuous casting process

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China Foundry 2024年第1期21卷 82-90页

作者： Kun Gao Yan peng School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004HebeiChina

To investigate the thermal and mechanical behavior of casting wheel,a two-dimensional thermoelastic-plastic finite element model was used to predict the temperature,stress and distortion distribution of the casting wheel during the wheel and belt continuous casting *** effects of grinding thickness and casting speed on the thermal and mechanical behaviors of the center of the hot face of the casting wheel were discussed in *** each rotation,the casting wheel passes through four different spray *** results show that the temperature distribution of the casting wheel in different spray zones is similar,the temperature of the hot face is the highest and the temperature reaches the peak in the spray zoneⅢ.The stress and distortion depend on the temperature distribution,and the maximum stress and distortion of the hot face are 358.2.MPa and 1.82.mm,*** temperature at the center of the hot face decreases with increasing grinding thickness and increases with increasing casting speed.

关键词： casting wheel finite element model grinding thickness casting speed hot face spray zones

Numerical simulation of fluid flow and free surface fluctuations during wheel and belt casting process

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Journal of Iron and Steel Research International 2024年第5期31卷 1117-1126页

作者： Kun Gao Yan peng National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao066004HebeiChina

The unstable fluid flow and severe free surface fluctuations in the wheel and belt caster can affect the quality of the cast *** lower level height tends to entrap inclusions in the molten *** the other hand,the higher level height makes the production process more dangerous due to the overflow of high temperature fluid from the mold.A computational model of the molten metal pouring process was *** transient fluid flow and free surface fluctuations behavior were calculated using the three-dimensional large eddy simulation model and the volume of fluid *** results show that the flow velocity of the main jet gradually decreases under the influence of the low kinetic energy fluid in the *** is an obvious oscillation in the tail of the jet,while the flow field is asymmetric in *** jet is closer to the inside radius side due to the Coanda effect,and there is a recirculation zone on the inside radius and the outside radius respectively,according to the 10 s time-averaged *** with the industrial observation and simulation results,the shape of the free surface is a wave that varies with *** addition,the free surface height is lowest and the flow velocity is highest in the region near the jet.

关键词： Fluid flow Free surface Wheel and belt caster Large eddy simulation Volume of fluid method

Two-Stage Online Debiased Lasso Estimation and Inference for High-Dimensional Quantile Regression with Streaming Data

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Journal of Systems Science & Complexity 2024年第3期37卷 1251-1270页

作者： peng Yanjin WANG Lei School of Statistics and Data Science KLMDASRLEBPS and LPMCNankai UniversityTianjin 300071China

In this paper,the authors propose a two-stage online debiased lasso estimation and statistical inference method for high-dimensional quantile regression(QR)models in the presence of streaming *** the first stage,the authors modify the QR score function based on kernel smoothing and obtain the online lasso smoothed QR estimator through iterative *** estimation process only involves the current data batch and specific historical summary statistics,which perfectly accommodates to the special structure of streaming *** the second stage,an online debiasing procedure is carried out to eliminate biases caused by the lasso penalty as well as the accumulative approximation error so that the asymptotic normality of the resulting estimator can be *** authors conduct extensive numerical experiments to evaluate the performance of the proposed *** experiments demonstrate the effectiveness of the proposed method and support the theoretical *** application to the Beijing PM2.5 Dataset is also presented.

关键词： Adaptive tuning asymptotic normality debiased lasso online updating quantile regres-sion