检索结果-南通市图书馆

Sequence structure controllable polymerization-induced self-assembly

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第1期67卷 390-397页

作者： Zi-Xuan Chang Ren-Man Zhu chun-Yan hong Wen-Jian Zhang Department of Polymer Science and Engineering University of Science and Technology of ChinaHefei 230026China Institute of Physical Science and Information Technology Anhui UniversityHefei 230601China Key Laboratory of Environment-Friendly Polymeric Materials of Anhui Province Anhui UniversityHefei 230601China

Polymerization-induced self-assembly(PISA)combines synthesis and self-assembly of artificial polymers in one-pot,which brings us one step closer to emulating ***,the reported PISA formulations primarily focus on developing nano-objects with new chemical compositions and rarely on structural regulation of polymers with specific ***,sequence structure controllable polymerization-induced self-assembly(SCPISA)is reported by using 7-(2-methacryloyloxyethoxy)-4-methylcoumarin(CMA)as a *** the copolymerization of 2-hydroxyethyl methacrylate(HEMA)and CMA,controlled incorporation of CMA units into the polymer chains can be realized by programmable light/heat ***-based P(HEMA-co-CMA)copolymers with the same composition but different sequence structures generate a range of ***,the morphologies of the resultant nano-objects can also be controlled by regulating the feed molar ratio of CMA and HEMA,which is similar to the conventional PISA,but the synthesis procedure is obviously simplified in *** versatility of the methodology is further demonstrated by the fabrication of different functional nano-objects with sequence structure-dependent morphologies in SCPISA systems with different functional monomers.

关键词： polymerization-induced self-assembly sequence-controlled polymers PET-RAFT polymerization

MiRNA-145-5p inhibits gastric cancer progression via the serpin family E member 1-extracellular signal-regulated kinase-1/2 axis

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2024年第5期16卷 2123-2140页

作者： hong-Xia Bai Xue-Mei Qiu chun-hong Xu Jian-Qiang Guo Department of Gastroenterology The Second Hospital of Shandong UniversityJinan 250000Shandong ProvinceChina Department of Gastroenterology Liaocheng People’s HospitalLiaocheng 252000Shandong ProvinceChina Department of Reproductive Center Zaozhuang Maternal and Child Health Care HospitalZaozhuang 277000Shandong ProvinceChina

BACKGROUND MicroRNAs(miRNAs)regulate gene expression and play a critical role in cancer ***,there is still a limited understanding of the function and regulatory mechanism of miRNAs in gastric cancer(GC).AIM To investigate the role and molecular mechanism of miRNA-145-5p(miR145-5p)in the progression of *** Real-time polymerase chain reaction(RT-PCR)was used to detect miRNA expression in human GC tissues and *** ability of cancer cells to migrate and invade was assessed using wound-healing and transwell assays,*** proliferation was measured using cell counting kit-8 and colony formation assays,and apoptosis was evaluated using flow *** of the epithelial-mesenchymal transition(EMT)-associated protein was determined by Western *** of miR-145-5p were predicated using bioinformatics analysis and verified using a dual-luciferase reporter *** family E member 1(SERPINE1)expression in GC tissues and cells was evaluated using RT-PCR and immunohistochemical *** correlation between SERPINE1 expression and overall patient survival was determined using Kaplan-Meier plot *** association between SERPINE1 and GC progression was also tested.A rescue experiment of SERPINE1 overexpression was conducted to verify the relationship between this protein and *** mechanism by which miR-145-5p influences GC progression was further explored by assessing tumor formation in nude *** GC tissues and cells had reduced miR-145-5p expression and SERPINE1 was identified as a direct target of this *** of miR-145-5p was associated with decreased GC cell proliferation,invasion,migration,and EMT,and these effects were reversed by forcing SERPINE1 ***-Meier plot analysis revealed that patients with higher SERPINE1 expression had a shorter survival rate than those with lower SERPINE1 *** mouse tumorigenesis experiments confirmed that miR-145-5p target

关键词： Gastric cancer MicroRNA-145-5p Serpin family E member 1 Epithelial-mesenchymal transition Proliferation Extracellular signal-regulated kinase-1/2

Significantly Enhanced Melt Memory Effect of Metallocene-made Isotactic Polypropylene Containing Talc

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第2期42卷 213-222,I0008页

作者： hong-Wen Sun Fu-Shan Wang Yan Gao Fu-Qing Wei Jia-chun Feng State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai200433China Lanzhou Petrochemical Corporation of PetroChina Lanzhou730060China Lanzhou Petrochemical Research Center Petrochemical Research Institute of PetroChinaLanzhou730060China

The melt memory effect is a widely observed phenomenon in semi-crystalline polymers. In practical applications, various additives are usually introduced into polymers, which may affect their melt memory behavior. In this work, the effect of talc on the melt memory effect of metallocene-made isotactic polypropylene(M-PP) was investigated in detail by using the differential scanning calorimetry. The results indicated that the introduction of talc significantly strengthened the melt memory effect of M-PP. Specifically, the upper limit temperature of Domain II increased from 161 ℃ to 174 ℃, resulting in a substantial widening of the temperature range of Domain IIa from 1 ℃ to 14 ℃. Analysis of the crystal orientation of the M-PP containing talc cooled from various Ts suggested that the remarkably enhanced melt memory effect could be ascribed to the stabilization of oriented nuclei facilitated by talc. This stabilizing effect was likely attributable to the prefreezing effect or the sorption interaction between talc and the M-PP chains.

关键词： Metallocene-made isotactic polypropylene Talc Melt memory effect Crystal orientation

Microstructure Evolution and Nanomechanical Behavior of Micro-Area in Molten Pool of Selective Laser Melting(CoCrNi)_(82)Al_(9)Ti_(9)High-Entropy Alloy

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2024年第6期37卷 1019-1033页

作者： hong-Wei Zhang Li-Wei Lan Zhe-Yu Yang Chang-chun Li Wen-Xian Wang College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan030024China Ministry of Education Key Laboratory of Interface Science and Engineering in Advanced MaterialsTaiyuan University of TechnologyTaiyuan030024China Shanxi-Zhejiang University New Materials and Chemical Research Institute Taiyuan030032China

In this work,the phase evolution mechanism and nanomechanical properties of(CoCrNi))(82)Al_(9)Ti_(9)high-entropy alloy(HEA)prepared by selective laser melting(SLM)in the molten pool were *** HEA contains multiple primary elements and undergoes high-temperature gradient and rapid cooling during *** leads to significant inhomogeneity of nano-scale microstructure characteristics and instability of *** optimizing process parameters,the microstructure evolution at the optimal parameter volume energy density of 440 J/mm^(3)was studied.A phase transition from BCC to FCC occurred in the melt *** the micro-area of the melt pool results in a temperature rise and the combustion-induced loss of Al ***,the Ni element content increases significantly outside the melt *** process enhances the phase stability of FCC and facilitates phase ***,rapid cooling leads to the formation of distinctive ultrafine equiaxial crystals inside the melt pool,accompanied by the generation of intracrystalline needle-like nano-scale *** the melt pool,the accumulation of energy results in the formation of coarse ***,the nano-hardness inside the molten pool is remarkably high at 11.79 GPa,while the outside the molten pool is reduced to 9.58 *** the fracture toughness outside the melt pool also *** with inside the melt pool,the residual stress outside the melt pool changed from compressive to tensile stress and decreased from 603.28 to 322.84 MPa.

关键词： High-entropy alloys Selective laser melting Microstructure evolution Nanoindentation

Elastic three-dimensional phononic topological insulators with Dirac hierarchy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 54-62页

作者： Shao-Yong Huo Qiu-Shuang Yang Jiu-Jiu Chen hong-Kang Li Long-Chao Yao Fu-chun He chun-Ming Fu College of Mechanical Engineering University of South ChinaHengyang 421001China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China

Three-dimensional(3D)phononic topological insulators(TIs)featuring two-dimensional(2D)surface states and one-dimensional(1D)hinge states have opened up a new route for multi-dimensional robust wave transport,providing unprecedented methods for integrated acoustic sensors and energy harvesting ***,aiming at the elastic 3D phononic TI with gapless surface states and hinge states,the realization of elastic 3D phononic TIs with gapless surface states and hinge states is a significant challenge due to the complicated multi-mode polarization of elastic waves in 3D *** this study,we demonstrate an elastic 3D phononic TI with a Dirac hierarchy by elaborately operating the corresponding spatial symmetries of the chiral honeycomb ***,a 3D double Dirac cone of elastic wave can be achieved by doubling the lattice along the outof-plane direction to fold two iso-frequency Weyl *** topological phase transitions and 2D gapless two-fold Dirac surface states of elastic wave are realized by breaking the half-lattice spatial translation ***,based on the Brillouin zone folding along the in-plane direction,the 2D gapless two-fold surface Dirac cones are folded into four-fold surface Dirac ***,by inducing the relative radius of adjacent holes to break the in-plane spatial inversion symmetry,the fourfold surface Dirac cones are gapped and associated with a surface state inversion,in which the gapless 1D hinge Dirac dispersion is *** research offers a route for engineering the hierarchies of TIs in 3D elastic wave systems and provides new possibilities for designing 3D ultrasonic devices with unconventional functions.

关键词： Dirac topological hierarchy

Concerted Steric and Electronic Strategy in Thermostable Salicylaldiminato Nickel Catalysts for Ethylene(Co)polymerization

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第8期42卷 1085-1092页

作者： hong-Yu Ji hong-Liang Mu chun-Feng Tang Yu-Xing Zhang Yue Chi Zhong-Bao Jian Key Laboratory of Advanced Structural Materials Ministry of EducationSchool of Materials Science and EngineeringChangchun University of TechnologyChangchun 130012China State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China

Olefin polymerization is one of the most im portant chemical reactions in *** work presents a strategy that emphasizes the synergistic meta/poro-steric hindrance of N-aryl groups and electronic effects in newly synthesized neutral salicylaldiminato nickel *** nickel(Ⅱ)catalysts exhibit exceptional thermostability,ranging from 30℃to 130℃,demonstrating enhanced catalytic activities and broadly regulated polyethylene molecular weights(3-341 kg·mol^(-1))and controlled polymer branch density(2-102 brs/1000C).The preferred catalyst Ni3 with concerted steric and electronic effects enables the production of solid-state semi-crystalline polyethylene materials at temperatures below 90℃.Notably,Ni3 exhibits an impressive tolerance of 110℃and can withstand even the challenging polymerization temperature of 130℃,leading to the production of polyethylene wax and ***,functionalized polyethylene is produced.

关键词： Polyolefin Salicylaldiminato ligand Nickel catalyst Oil Wax

Modeling and characterization on electroplastic effect during dynamic deformation of 5182-O aluminum alloy

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2024年第8期34卷 2455-2475页

作者： hong-chun SHANG Song-chen WANG Yan-shan LOU School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710049China

The coupling effects of electrical pulse,temperature,strain rate,and strain on the flow behavior and plasticity of 5182-O aluminum alloy were investigated and *** isothermal tensile test and electrically-assisted isothermal tensile test were performed at the same temperature,and three typical models were further embedded in ABAQUS/Explicit for numerical simulation to illustrate the electroplastic *** results show that electric pulse reduces the deformation resistance but enhances the elongation *** calibration accuracy of the proposed modified Lim−Huh model for highly nonlinear and coupled dynamic hardening behavior is not much improved compared to the modified Kocks−Mecking ***,the artificial neural network model is very suitable to describe the macromechenical response of materials under the coupling effect of different variables.

关键词： machine learning aluminium alloy electroplastic effect coupling effect finite element analysis

Mechanism of local solidification time variations with melt rate during vacuum arc remelting process of 8Cr4Mo4V high-strength steel

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第2期31卷 377-388页

作者： Tao Pan hong-chun Zhu Zhou-hua Jiang Hua-bing Li Rui Zhang Hao Feng School of Metallurgy Northeastern UniversityShenyang110819LiaoningChina State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819LiaoningChina

A 2D axisymmetric numerical model was established to investigate the variations of molten pool with different melt rates during the vacuum arc remelting of 8Cr4Mo4V high-strength steel,and the ingot growth was simulated by dynamic mesh *** results show that as the ingot grows,the molten pool profile changes from shallow and flat to V-shaped,and both the molten pool depth and the mushy width ***,the variation of both the molten pool shape and the mushy width melt rate is clarified by the thermal equilibrium *** melt rate increases,both the molten pool depth and the mushy width *** is caused by the increment in sensible heat stored in the ingot due to the limitation of the cooling capacity of the *** nonlinear increment in sensible heat leads to a nonlinear increase in the mushy *** addition,as melt rate increases,the local solidification time(LST)of ingot decreases obviously at first and then *** melt rate is controlled in a suitable range,LST is the lowest and the secondary dendrite arm spacing of the ingot is the smallest,which can effectively improve the compactness degree of 8Cr4Mo4V high-strength steel.

关键词： 8Cr4Mo4V high-strength steel Vacuum arc remelting process Melt rate Molten pool Local solidification time

Percutaneous transhepatic cholangioscopy-assisted biliary polypectomy for local palliative treatment of intraductal papillary neoplasm of the bile duct

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2024年第5期16卷 1821-1832页

作者： Xu Ren Yong-Ping Qu chun-Lan Zhu Xiao-hong Xu hong Jiang Yi-Xia Lu hong-Peng Xue Digestive Disease Hospital of Heilongjiang Provincial Hospital Heilongjiang Provincial Clinical Medical Research Center for Minimally Invasive Diagnosis and Treatment of Pancreaticobiliary DiseasesHarbin 150001Heilongjiang ProvinceChina Digestive Endoscopy Center of Heilongjiang Provincial Hospital Heilongjiang Provincial Clinical Medical Research Center for Minimally Invasive Diagnosis and Treatment of Pancreaticobiliary DiseasesHarbin 150001Heilongjiang ProvinceChina Second Department of Gastroenterology Digestive Disease Hospital of Heilongjiang Provincial Hospitaland Heilongjiang Provincial Clinical Medical Research Center for Minimally Invasive Diagnosis and Treatment of Pancreaticobiliary DiseasesHarbin 150001Heilongjiang ProvinceChina Department of Pathology Heilongjiang Provincial HospitalHarbin 150001Heilongjiang ProvinceChina

BACKGROUND Intraductal papillary neoplasm of the bile duct(IPNB)is a premalignant biliarytype epithelial neoplasm with intraductal papillary or villous *** reported local palliative therapeutic modalities,including endoscopic nasobiliary drainage,stenting and biliary curettage,endoscopic biliary polypectomy,percutaneous biliary drainage,laser ablation,argon plasma coagulation,photodynamic therapy,and radiofrequency ablation to relieve mechanical obstruction are limited with weaknesses and *** have applied percutaneous transhepatic cholangioscopy(PTCS)-assisted biliary polypectomy(PTCS-BP)technique for the management of IPNB including mucin-hypersecreting cast-like and polypoid type tumors since *** To assess the technical feasibility,efficacy,and safety of PTCS-BP for local palliative treatment of *** Patients with mucin-hypersecreting cast-like or polypoid type IPNB and receiving PTCS-BP between September 2010 and December 2019 were ***-BP was performed by using a half-moon type snare with a soft stainless-steel wire,and the tumor was snared and resected with *** primary outcome was its feasibility,indicated by technical *** secondary outcomes were efficacy,including therapeutic success,curative resection,and clinical success,and *** Five patients(four with mucin-hypersecreting cast-like type and one with polypoid type IPNB)were ***-and high-grade intraepithelial neoplasia(HGIN)and recurrent IPNB with invasive carcinoma were observed in one,two,and two patients,*** cholangitis and/or obstructive jaundice were presented in all four patients with mucin-hypersecreting cast-like type *** five patients achieved technical success of *** patients(three with mucin-hypersecreting cast-like type and one with polypoid type IPNB)obtained therapeutic success;one with mucin-hypersecreting cast-like type tumors in the intrahepatic small bile duct and HGIN h

关键词： Intraductal papillary neoplasm of the bile duct Percutaneous transhepatic cholangioscopy Biliary polypectomy Feasibility Efficacy