Follicle-stimulating hormone (FSH) plays a central role in mammals reproduction, with the actions of FSH mediated by follicle-stimulating hormone receptors (FSHRs) on the surface of target cells. The purposes of this ...Follicle-stimulating hormone (FSH) plays a central role in mammals reproduction, with the actions of FSH mediated by follicle-stimulating hormone receptors (FSHRs) on the surface of target cells. The purposes of this study were to determine and evaluate the biological activities for the commercialization of recombinant follicle-stimulating hormone (rFSH) in vitro through the cellular internalization using cloned 293T-FSHR cell lines as target. Using imaging approaches we have found here that a little fluorescent signal from the surface of the cell transferred to the cytoplasm and accumulated around the nucleus by endocytosis. Compared with the control groups, the commercialization of rFSH have not the significant differences of internalization, but the rFSH have promoted the internalization of the fluorescent, suggested that this detection system might as a protocol for the bioactivity of recombinant therapeutic proteins in vitro.展开更多
Understanding the processes of charge generation, transfer and capture is important for the design and synthesis of efficient photocatalysts. In this work, light-induced charge separation and effect of O_(2) on electr...Understanding the processes of charge generation, transfer and capture is important for the design and synthesis of efficient photocatalysts. In this work, light-induced charge separation and effect of O_(2) on electron transfer processes in SrTiO_(3) were investigated by electron paramagnetic resonance(EPR). It was found that photoinduced electron transfer from O_(2)- to Ti^(4+) produced Ti^(3+) and O- redox radical pairs under vacuum condition. Under oxygen atmosphere, however, surface bound superoxide radicals O_(2)-were formed by electron reduction of adsorbed oxygen at initial photoirradiation stage, and quenched by the reverse electron transfer to Ti^(4+) upon further photoirradiation. Formation of long-lived charge separation associated [Ti^(3+)---O-] species and the reversibility of surface bound superoxide radicals mediating the processes of photogenerated electrons may be accountable for the high activity of SrTiO_(3) in photocatalytic water splitting reaction.展开更多
Our previous study found that the adsorption performance of porous carbon for Gd(Ⅲ) could be significantly improved by increasing the N,and O functional groups on its surface.Unfortunately,the adsorption capacity of ...Our previous study found that the adsorption performance of porous carbon for Gd(Ⅲ) could be significantly improved by increasing the N,and O functional groups on its surface.Unfortunately,the adsorption capacity of porous carbon is low due to the limited number of N,and O functional groups that can be loaded on its surface.Due to the advantage of customizable functional groups of porous organic polymers(POPs),the triazine-based Tb-MEL and hydroxyl-modified triazine-based Tp-MEL were synthesized by a one-step hydrothermal method using nitrogen-rich melamine as the raw material and triformylbenzene(Tb) and 2,4,6-triformylphloroglucinol(Tp),respectively.The Gd(Ⅲ) adsorption isotherms and kinetic curves of Tb-MEL,and Tp-MEL at pH=6 and T=25℃ are in high agreement with the Langmuir isotherm(R^(2)>0.998) and pseudo-second-order kinetics(R^(2)>0.993),respectively.The fitted maximum adsorption capacity(q_(max)) is about 136.05 mg/g,much higher than 58.38 mg/g of Tb-MEL.The adsorption efficiency for Gd(Ⅲ) at pH=7 is close to 100%,and Tp-MEL maintains 62.4% of the initial adsorption capacity after ten cycle s of sorption/desorption of Gd(Ⅲ),with an average elution efficiency of more than 90%.Adsorption selection performance tests show that Tp-MEL has good adsorption selectivity for HREE ions,and the selectivity is as follows:Lu^(3+)>Y^(3+)>Gd^(3+)>Nd^(3+)>La^(3+)>Al^(3+)>Ca^(2+)>Mg^(2+).Batch adsorption,Brunauer-Emmett-Teller(BET) method,and X-ray photoelectron spectrometer(XPS)tests show that hydroxyl modifications lose the specific surface area of the polymer,and the functional groups contribute more to the adsorption performance than the specific surface area.展开更多
Plasmonic photocatalysis with tunable light absorption has aroused significant attention in so-lar-to-chemical energy conversion.However,the energy conversion efficiency of plasmonic photo-catalysts is impeded by inef...Plasmonic photocatalysis with tunable light absorption has aroused significant attention in so-lar-to-chemical energy conversion.However,the energy conversion efficiency of plasmonic photo-catalysts is impeded by ineffective charge separation and the lack of highly active sites for redox reactions.In this work,the Au nanoparticle size and Au-TiO2 interaction of the Au/TiO2 plasmonic photocatalyst were adjusted simultaneously using a post-calcination treatment.The visi-ble-ight-induced water oxidation activity exhibited a volcano-like relationship with the calcination temperature;the treated photocatalyst at 600°C manifested the highest activity.Characterization with UV-visible spectra,XRD,SEM,and XPS revealed that the effect of the Au nanoparticle size and Au-TiO2 interaction were both responsible for the increase in plasmon-induced water oxidation activity.展开更多
Nanowires(NWs)and self-assemble nanostructures made of chalcogenide semiconductor nanocrystals(NCs)are of great interests to the fundamental studies and practical applications.In this study,we reported a seeded-mediat...Nanowires(NWs)and self-assemble nanostructures made of chalcogenide semiconductor nanocrystals(NCs)are of great interests to the fundamental studies and practical applications.In this study,we reported a seeded-mediated growth of AgInS_(2)NWs and their intriguing self-assembly nanostructures with fingerprint-like shape.The key to the formation and self-assembly of AgInS_(2)NWs was the presence of In-S species that was a type of molecular metal chalcogenide complexes,serving as specific inorganic ligands for the growth of NWs and cross-linker molecules for the self-assembly of fingerprint-like nanostructures.Systematic studies were carried out to investigate the reaction factors,including the thermodynamics,amount and type of In precursors,and 1-dodecanethiol usage,to the success of the desired products.展开更多
AIM:To isolate and analyze the DNA sequences which are methylated differentially between gastric cancer and normal gastric mucosa. METHODS: The differentially methylated DNA sequences between gastric cancer and normal...AIM:To isolate and analyze the DNA sequences which are methylated differentially between gastric cancer and normal gastric mucosa. METHODS: The differentially methylated DNA sequences between gastric cancer and normal gastric mucosa were isolated by methylation-sensitive representational difference analysis (MS-RDA). Similarities between the separated fragments and the human genomic DNA were analyzed with Basic Local Alignment Search Tool (BLAST). RESULTS: Three differentially methylated DNA sequences were obtained, two of which have been accepted by GenBank. The accession numbers are AY887106 and AY887107. AY887107 was highly similar to the 11th exon of LOC440683 (98%), 3' end of LOC440887 (99%), and promoter and exon regions of DRD5 (94%). AY887106 was consistent (98%) with a CpG island in ribosomal RNA isolated from colorectal cancer by Minoru Toyota in 1999. CONCLUSION: The methylation degree is different between gastric cancer and normal gastric mucosa. The differentially methylated DNA sequences can be isolated effectively by MS-RDA.展开更多
A novel hot rolled steel LG600A with the tensile strength exceeding 700 MPa was developed for automatic teller machine application. Thelow-cost C-Mn steel was microalloyed with：0.08 mass%- 0.12 mass% Ti rather than n...A novel hot rolled steel LG600A with the tensile strength exceeding 700 MPa was developed for automatic teller machine application. Thelow-cost C-Mn steel was microalloyed with：0.08 mass%- 0.12 mass% Ti rather than noble alloying elements, such as Nb, V, Mo, and Cu, etc. The novel steel had a good surface quality and welding property. After the hot rolled steel coils were leveled, the steel plates, the length of which was even down to 1 500 mm, had an excellent flatness. The effects of hot rolling parameters on mechanical per formance, m icrostructure and recrystallization behavior were studied. The metallurgical concept for the steel production was also discussed. The result shows that decreasing the finish rolling temperature, increasing cooling rate in the first cooling stage and decreasing the cooling rate in the last cooling stage, together with coiling at a modestly high coiling temperature all resulted in the refined grains and TiC precipitates, thereby improving the strength and toughness of this new steel greatly.展开更多
The investigation based on experiments and crystal plasticity simulation is carried out to undertake research on mesodeformation inhomogeneity of metals under cyclic loading at grain level.Symmetrical tension-compress...The investigation based on experiments and crystal plasticity simulation is carried out to undertake research on mesodeformation inhomogeneity of metals under cyclic loading at grain level.Symmetrical tension-compression cycle tests are performed on pure copper specimens to observe the inhomogeneous distribution of slip deformation and its evolution with cycle number.Cyclic hardening process and stable hysteretic behavior of pure copper under cyclic loading are simulated by applying a crystal plasticity constitutive model including nonlinear kinematic hardening associated with the polycrystalline representative volume element(RVE)constructed by Voronoi tessellation.Inhomogeneous deformation processes of materials under six different strain amplitudes are simulated by 1600 cycles,respectively.We discuss the variation law of the inhomogeneous meso-deformation distribution of material with the increase in cycle number,and research the rationality of characterizing the inhomogeneous deformation distribution and variation with the statistical standard deviation of the micro-longitudinal strain or the statistical average of the first principal strain based on the statistical analysis of the inhomogeneous deformation of the polycrystalline RVE model during the cycling process.It is found that these two parameters are related to and approximately inversely proportional to the length of measuring gauge.展开更多
The Zygosaccharomyces rouxii is a kind of fermentation yeast which yield flavoring substance in the production of soy sauce. In order to the overexpression of the target protein in wild type strains, we choose PYEs2.0...The Zygosaccharomyces rouxii is a kind of fermentation yeast which yield flavoring substance in the production of soy sauce. In order to the overexpression of the target protein in wild type strains, we choose PYEs2.0 as the original carrier, the acyl-coA binding protein (ACBP) and GFP gene have been cloned in the multiple cloning site. The screening of labeled URA3 gene was replaced by KanMX gene which anti G418. The vector was obtained through the screening of G418 at the concentration of 25 ug/ml.展开更多
The first fractured shale gas well of China was constructed in 2010.After 10 years of development,China has become the second country that possesses the core technology of shale gas development around the world,realiz...The first fractured shale gas well of China was constructed in 2010.After 10 years of development,China has become the second country that possesses the core technology of shale gas development around the world,realized the shale gas fracturing techniques from zero to one and from lagging to partially leading,and constructed the fracturing theory and technology system suitable for middle-shallow marine shale gas exploitation.In order to provide beneficial guidance for the efficient exploitation of shale gas in China in the future,this paper comprehensively reviews development history and status of domestic fundamental theories,optimized design methods,fluid systems,tools and technologies of shale gas fracturing and summarizes the research results in fundamental theories and optimized design methods,such as fracturing sweet-spot cognition,fracture network propagation simulation and control,rock hydration and flowback control,and SRV(stimulated reservoir volume)evaluation and characterization.The development and application of slick-water fracturing fluid system and new fracturing fluid with little or no water is discussed.The development and independent research&development level of multi-stage fracturing tools are evaluated,including drillable composite plug,soluble plug,large-diameter plug and casing cementing sleeve.The implementation situations of field technologies and processes are illustrated,including the early conventional multi-stage multi-cluster fracturing and the current“dense cluster”fracturing and temporary plugging fracturing.Based on this,the current challenges to domestic shale gas fracturing technologies are analyzed systematically,and the development direction of related technologies is forecast.In conclusion,it is necessary for China to continuously research the fracturing theories,technologies and methods suitable for domestic deep and ultra-deep marine shale gas,terrestrial shale gas and transitional shale gas to facilitate the future efficient development of shale gas in China.展开更多
Refractories have an important effect on the cleanliness of molten steel.The interaction between CeAlO_(3) refractories and Ce treated steel was explored and compared with that between Al_(2)O_(3) refractories and Ce ...Refractories have an important effect on the cleanliness of molten steel.The interaction between CeAlO_(3) refractories and Ce treated steel was explored and compared with that between Al_(2)O_(3) refractories and Ce treated steel.The results show that the Ce content in steel decreases sharply after contact with Al_(2)O_(3) refractories and the pick-up of dissolved Al occurs.Compared with the test of Al_(2)O_(3) refractories,the loss of Ce content is less in the test of CeAlO_(3) refractory,and the total oxygen content and dissolved Al content in steel increase less.The dense and continuous Ce_(2)O_(2)S interface layer is observed at the CeAlO_(3) refractories/steel interface,which can serve as the metallurgical isolation layer and hinder the further interaction between refractories and steel.Therefore,the higher steel cleanliness and less penetration of refractories by molten steel are obtained in the test of CeAlO_(3) refractories.The CeAlO_(3) refractories show a promising prospect in the production of clean Ce treated steel.展开更多
In this work,the theoretical analysis and experiment results investigating the influence of plasma-induced reflected wave variations on microwave transmission characterization are presented.Firstly,an analytical trans...In this work,the theoretical analysis and experiment results investigating the influence of plasma-induced reflected wave variations on microwave transmission characterization are presented.Firstly,an analytical transmission line model for transmission characterization of plasma in shock tube is derived and validated against full-wave simulation.Then,the theoretical analysis of transmission characterization based on a time-dependent reconstruction algorithm that takes into account the variations of reflected wave is presented and the influence of reflection variations under various states of plasma is also investigated.The unusual increase in the amplitude of transmitted wave is theoretically predicted and experimentally demonstrated as well.Finally,the experiment results are also presented to illustrate the effects of reflected wave variations in practical microwave transmission characterization of supersonic plasma excited in shock tube.展开更多
Follicle stimulating hormone (FSH) is a kind of glycoprotein gonadotropin, and plays an important role in the diagnosis and treatment of infertility. Follicle stimulating hormone receptor (FSHR) is a kind of G protein...Follicle stimulating hormone (FSH) is a kind of glycoprotein gonadotropin, and plays an important role in the diagnosis and treatment of infertility. Follicle stimulating hormone receptor (FSHR) is a kind of G protein coupled receptor (GPCR), found in the ovary and testes, and its activation is required for the hormonal operation during the breeding period. In this study, an experimental model of FSHR mediated FSH into cell membrane, which exhibited a phenomenon of fluorescent localized on cell surfaces internalized into cell interior, was established to verify biological activity of FSH.展开更多
To discuss the structure design and optimization of building curtain wall, the dynamic characteristics of point supported glass curtain wall system are analyzed by the finite element method. The various technologies a...To discuss the structure design and optimization of building curtain wall, the dynamic characteristics of point supported glass curtain wall system are analyzed by the finite element method. The various technologies are made use of, and according to the characteristics of the structure system, the finite element analysis model with steel structure glass plate beam element and shell element as the basic elements is established. Then, the dynamic characteristics are analyzed, and the modal parameters such as inherent frequency and vibration type are identified. The research results show that the node displacement response power spectrum under the load of wind is obtained, which provides the basis for rationally optimizing the structure. Based on the above findings, it is concluded that the optimization design based on finite element model has a wide significance, which is a useful attempt to reduce the blindness of design and has great engineering significance and application value.展开更多
Chondrocyte is considered the only cell type in cartilage.However,the cell hetero-geneity of chondrocytes in human articular cartilage is still not well defined,which hinders our understanding of the pathogenesis of o...Chondrocyte is considered the only cell type in cartilage.However,the cell hetero-geneity of chondrocytes in human articular cartilage is still not well defined,which hinders our understanding of the pathogenesis of osteoarthritis(OA).Here,we constructed a single-cell transcriptomic atlas of chondrocytes in healthy cartilage and identified nine chondrocyte sub-sets including homeostatic chondrocytes,proliferate fibrochondrocytes,and hypertrophic chondrocytes(HTC).Interestingly,we identified two distinct HTC subpopulations,among which HTC-1 specifically expressed genes associated with apoptosis and programmed cell death.We identified two main trajectories of chondrocytes,one of which differentiates into fibrochondrocytes,while the other terminates in apoptosis.Comparison of chondrocyte subsets between healthy and OA cartilage showed that proliferate fibrochondrocytes and HTC-1 expanded in OA patients,whereas homeostatic chondrocytes decreased.Interestingly,we discovered an OA-specific proliferate fibrochondrocyte subset that may contribute to the development of OA via inflammation.In summary,this study significantly enhanced our understanding of cell heterogeneity of chondrocytes in articular cartilage and provides insight into the pathogenesis of OA.展开更多
Per-and polyfluoroalkyl substances(PFAS)are persistent environmental pollutants known for their bioaccumulative nature.Reduced bone mineral density(BMD)is associated with an increased risk of developing osteoporosis.T...Per-and polyfluoroalkyl substances(PFAS)are persistent environmental pollutants known for their bioaccumulative nature.Reduced bone mineral density(BMD)is associated with an increased risk of developing osteoporosis.This pioneering study aims to assess the effects of different PFAS compounds on bone mineral.We conducted searches on online databases.Inclusion criteria included the presence of associations between perfluorooctanoic acid(PFOA),perfluorooctanesulfonate(PFOS),perfluorohexanesulfonic acid(PFHxS),perfluorononanoic acid(PFNA),and perfluorodecanoic acid(PFDA)and BMD,BMD zscore,and bone mineral content(BMC).Meta-analyses were performed.Best evidence synthesis(BES)was performed to summarize the results.The results of BES showed that the evidence of PFOS,PFOA and PFNA with reduced bone mineral were moderate.The variability in methods for assessing bone mineral and sex differences are potential sources of heterogeneity in the results.Meta analysis showed that PFOA was associated with BMD(β−0.01,95%CI−0.01 to−0.00;I^(2)=0%).Subgroup analysis by sex showed that PFOS(β−0.01,95%CI−0.01 to−0.00;I^(2)=50%),PFOA(β−0.01,95%CI−0.01 to+0.00;I^(2)=29%)were negatively correlated with BMD.This systematic review and BES revealed negative correlations between exposure to PFOS,PFOA,PFNA and bone mineral.Sex emerged as a potential factor affecting the negative effects of PFAS on bone mineral.The damage of PFAS to bone mineral still requires further exploration.展开更多
文摘Follicle-stimulating hormone (FSH) plays a central role in mammals reproduction, with the actions of FSH mediated by follicle-stimulating hormone receptors (FSHRs) on the surface of target cells. The purposes of this study were to determine and evaluate the biological activities for the commercialization of recombinant follicle-stimulating hormone (rFSH) in vitro through the cellular internalization using cloned 293T-FSHR cell lines as target. Using imaging approaches we have found here that a little fluorescent signal from the surface of the cell transferred to the cytoplasm and accumulated around the nucleus by endocytosis. Compared with the control groups, the commercialization of rFSH have not the significant differences of internalization, but the rFSH have promoted the internalization of the fluorescent, suggested that this detection system might as a protocol for the bioactivity of recombinant therapeutic proteins in vitro.
基金financially supported by the National Key R&D Program of China under contact No.2017YFA0204804the National Natural Science Foundation of China under contact Nos.21761142018,21473189 and 22088102 for supporting Fundamental Research Center of Artificial Photosynthesis(FRe CAP)。
文摘Understanding the processes of charge generation, transfer and capture is important for the design and synthesis of efficient photocatalysts. In this work, light-induced charge separation and effect of O_(2) on electron transfer processes in SrTiO_(3) were investigated by electron paramagnetic resonance(EPR). It was found that photoinduced electron transfer from O_(2)- to Ti^(4+) produced Ti^(3+) and O- redox radical pairs under vacuum condition. Under oxygen atmosphere, however, surface bound superoxide radicals O_(2)-were formed by electron reduction of adsorbed oxygen at initial photoirradiation stage, and quenched by the reverse electron transfer to Ti^(4+) upon further photoirradiation. Formation of long-lived charge separation associated [Ti^(3+)---O-] species and the reversibility of surface bound superoxide radicals mediating the processes of photogenerated electrons may be accountable for the high activity of SrTiO_(3) in photocatalytic water splitting reaction.
基金supported by the National Natural Science Foundation of China (41662004)。
文摘Our previous study found that the adsorption performance of porous carbon for Gd(Ⅲ) could be significantly improved by increasing the N,and O functional groups on its surface.Unfortunately,the adsorption capacity of porous carbon is low due to the limited number of N,and O functional groups that can be loaded on its surface.Due to the advantage of customizable functional groups of porous organic polymers(POPs),the triazine-based Tb-MEL and hydroxyl-modified triazine-based Tp-MEL were synthesized by a one-step hydrothermal method using nitrogen-rich melamine as the raw material and triformylbenzene(Tb) and 2,4,6-triformylphloroglucinol(Tp),respectively.The Gd(Ⅲ) adsorption isotherms and kinetic curves of Tb-MEL,and Tp-MEL at pH=6 and T=25℃ are in high agreement with the Langmuir isotherm(R^(2)>0.998) and pseudo-second-order kinetics(R^(2)>0.993),respectively.The fitted maximum adsorption capacity(q_(max)) is about 136.05 mg/g,much higher than 58.38 mg/g of Tb-MEL.The adsorption efficiency for Gd(Ⅲ) at pH=7 is close to 100%,and Tp-MEL maintains 62.4% of the initial adsorption capacity after ten cycle s of sorption/desorption of Gd(Ⅲ),with an average elution efficiency of more than 90%.Adsorption selection performance tests show that Tp-MEL has good adsorption selectivity for HREE ions,and the selectivity is as follows:Lu^(3+)>Y^(3+)>Gd^(3+)>Nd^(3+)>La^(3+)>Al^(3+)>Ca^(2+)>Mg^(2+).Batch adsorption,Brunauer-Emmett-Teller(BET) method,and X-ray photoelectron spectrometer(XPS)tests show that hydroxyl modifications lose the specific surface area of the polymer,and the functional groups contribute more to the adsorption performance than the specific surface area.
基金supported by the National Natural Science Foundation of China (21633010)the National Basic Research Program of China (973 pro‐gram, 2014CB239400)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB01020300)~~
文摘Plasmonic photocatalysis with tunable light absorption has aroused significant attention in so-lar-to-chemical energy conversion.However,the energy conversion efficiency of plasmonic photo-catalysts is impeded by ineffective charge separation and the lack of highly active sites for redox reactions.In this work,the Au nanoparticle size and Au-TiO2 interaction of the Au/TiO2 plasmonic photocatalyst were adjusted simultaneously using a post-calcination treatment.The visi-ble-ight-induced water oxidation activity exhibited a volcano-like relationship with the calcination temperature;the treated photocatalyst at 600°C manifested the highest activity.Characterization with UV-visible spectra,XRD,SEM,and XPS revealed that the effect of the Au nanoparticle size and Au-TiO2 interaction were both responsible for the increase in plasmon-induced water oxidation activity.
基金supported by the National Natural Science Foundation of China(Nos.61735004 and 61974009)the Key Laboratory of New Energy and Rare Earth Resource Utilization of State Ethnic Affairs Commission(No.NERE201903)。
文摘Nanowires(NWs)and self-assemble nanostructures made of chalcogenide semiconductor nanocrystals(NCs)are of great interests to the fundamental studies and practical applications.In this study,we reported a seeded-mediated growth of AgInS_(2)NWs and their intriguing self-assembly nanostructures with fingerprint-like shape.The key to the formation and self-assembly of AgInS_(2)NWs was the presence of In-S species that was a type of molecular metal chalcogenide complexes,serving as specific inorganic ligands for the growth of NWs and cross-linker molecules for the self-assembly of fingerprint-like nanostructures.Systematic studies were carried out to investigate the reaction factors,including the thermodynamics,amount and type of In precursors,and 1-dodecanethiol usage,to the success of the desired products.
基金The Key Project Fund of the Science and Technology Program of Hunan Province, No. 04SK1004the Scientific Research Fund of Educational Department, Hunan Province, No. 99C195
文摘AIM:To isolate and analyze the DNA sequences which are methylated differentially between gastric cancer and normal gastric mucosa. METHODS: The differentially methylated DNA sequences between gastric cancer and normal gastric mucosa were isolated by methylation-sensitive representational difference analysis (MS-RDA). Similarities between the separated fragments and the human genomic DNA were analyzed with Basic Local Alignment Search Tool (BLAST). RESULTS: Three differentially methylated DNA sequences were obtained, two of which have been accepted by GenBank. The accession numbers are AY887106 and AY887107. AY887107 was highly similar to the 11th exon of LOC440683 (98%), 3' end of LOC440887 (99%), and promoter and exon regions of DRD5 (94%). AY887106 was consistent (98%) with a CpG island in ribosomal RNA isolated from colorectal cancer by Minoru Toyota in 1999. CONCLUSION: The methylation degree is different between gastric cancer and normal gastric mucosa. The differentially methylated DNA sequences can be isolated effectively by MS-RDA.
文摘A novel hot rolled steel LG600A with the tensile strength exceeding 700 MPa was developed for automatic teller machine application. Thelow-cost C-Mn steel was microalloyed with：0.08 mass%- 0.12 mass% Ti rather than noble alloying elements, such as Nb, V, Mo, and Cu, etc. The novel steel had a good surface quality and welding property. After the hot rolled steel coils were leveled, the steel plates, the length of which was even down to 1 500 mm, had an excellent flatness. The effects of hot rolling parameters on mechanical per formance, m icrostructure and recrystallization behavior were studied. The metallurgical concept for the steel production was also discussed. The result shows that decreasing the finish rolling temperature, increasing cooling rate in the first cooling stage and decreasing the cooling rate in the last cooling stage, together with coiling at a modestly high coiling temperature all resulted in the refined grains and TiC precipitates, thereby improving the strength and toughness of this new steel greatly.
基金the National Natural Science Foundation of China(Nos.11632007 and 11472085)the Project of Promoting the Basic Ability of Scientific Research of Young and Middle-aged Teachers in Universities of Guangxi(No.2019KY1365),which are gratefully acknowledged.
文摘The investigation based on experiments and crystal plasticity simulation is carried out to undertake research on mesodeformation inhomogeneity of metals under cyclic loading at grain level.Symmetrical tension-compression cycle tests are performed on pure copper specimens to observe the inhomogeneous distribution of slip deformation and its evolution with cycle number.Cyclic hardening process and stable hysteretic behavior of pure copper under cyclic loading are simulated by applying a crystal plasticity constitutive model including nonlinear kinematic hardening associated with the polycrystalline representative volume element(RVE)constructed by Voronoi tessellation.Inhomogeneous deformation processes of materials under six different strain amplitudes are simulated by 1600 cycles,respectively.We discuss the variation law of the inhomogeneous meso-deformation distribution of material with the increase in cycle number,and research the rationality of characterizing the inhomogeneous deformation distribution and variation with the statistical standard deviation of the micro-longitudinal strain or the statistical average of the first principal strain based on the statistical analysis of the inhomogeneous deformation of the polycrystalline RVE model during the cycling process.It is found that these two parameters are related to and approximately inversely proportional to the length of measuring gauge.
文摘The Zygosaccharomyces rouxii is a kind of fermentation yeast which yield flavoring substance in the production of soy sauce. In order to the overexpression of the target protein in wild type strains, we choose PYEs2.0 as the original carrier, the acyl-coA binding protein (ACBP) and GFP gene have been cloned in the multiple cloning site. The screening of labeled URA3 gene was replaced by KanMX gene which anti G418. The vector was obtained through the screening of G418 at the concentration of 25 ug/ml.
文摘The first fractured shale gas well of China was constructed in 2010.After 10 years of development,China has become the second country that possesses the core technology of shale gas development around the world,realized the shale gas fracturing techniques from zero to one and from lagging to partially leading,and constructed the fracturing theory and technology system suitable for middle-shallow marine shale gas exploitation.In order to provide beneficial guidance for the efficient exploitation of shale gas in China in the future,this paper comprehensively reviews development history and status of domestic fundamental theories,optimized design methods,fluid systems,tools and technologies of shale gas fracturing and summarizes the research results in fundamental theories and optimized design methods,such as fracturing sweet-spot cognition,fracture network propagation simulation and control,rock hydration and flowback control,and SRV(stimulated reservoir volume)evaluation and characterization.The development and application of slick-water fracturing fluid system and new fracturing fluid with little or no water is discussed.The development and independent research&development level of multi-stage fracturing tools are evaluated,including drillable composite plug,soluble plug,large-diameter plug and casing cementing sleeve.The implementation situations of field technologies and processes are illustrated,including the early conventional multi-stage multi-cluster fracturing and the current“dense cluster”fracturing and temporary plugging fracturing.Based on this,the current challenges to domestic shale gas fracturing technologies are analyzed systematically,and the development direction of related technologies is forecast.In conclusion,it is necessary for China to continuously research the fracturing theories,technologies and methods suitable for domestic deep and ultra-deep marine shale gas,terrestrial shale gas and transitional shale gas to facilitate the future efficient development of shale gas in China.
基金the National Natural Science Foundation of China(Nos.U1860205 and 52004189)Project of Hubei Provincial Department of Science and Technology(Nos.2022BAA021 and 2022CFB051)+1 种基金China Postdoctoral Science Foundation(Nos.2022M721109 and 2023T160210)Young Elite Scientists Sponsorship Program by CAST(No.2022QNRC001).
文摘Refractories have an important effect on the cleanliness of molten steel.The interaction between CeAlO_(3) refractories and Ce treated steel was explored and compared with that between Al_(2)O_(3) refractories and Ce treated steel.The results show that the Ce content in steel decreases sharply after contact with Al_(2)O_(3) refractories and the pick-up of dissolved Al occurs.Compared with the test of Al_(2)O_(3) refractories,the loss of Ce content is less in the test of CeAlO_(3) refractory,and the total oxygen content and dissolved Al content in steel increase less.The dense and continuous Ce_(2)O_(2)S interface layer is observed at the CeAlO_(3) refractories/steel interface,which can serve as the metallurgical isolation layer and hinder the further interaction between refractories and steel.Therefore,the higher steel cleanliness and less penetration of refractories by molten steel are obtained in the test of CeAlO_(3) refractories.The CeAlO_(3) refractories show a promising prospect in the production of clean Ce treated steel.
基金supported by National Natural Science Foundation of China(Nos.62001095 and U20B2043)the Fundamental Research Funds for the Central Universities of China(No.ZYGX2018KYQD200)+1 种基金the National Science and Technology Major Project of the Ministry of Science and Technology of China(No.SQ2019YFA040012)the National Defense Basic Scientific Research Program of China(No.2020-JCJQ-ZD-072)。
文摘In this work,the theoretical analysis and experiment results investigating the influence of plasma-induced reflected wave variations on microwave transmission characterization are presented.Firstly,an analytical transmission line model for transmission characterization of plasma in shock tube is derived and validated against full-wave simulation.Then,the theoretical analysis of transmission characterization based on a time-dependent reconstruction algorithm that takes into account the variations of reflected wave is presented and the influence of reflection variations under various states of plasma is also investigated.The unusual increase in the amplitude of transmitted wave is theoretically predicted and experimentally demonstrated as well.Finally,the experiment results are also presented to illustrate the effects of reflected wave variations in practical microwave transmission characterization of supersonic plasma excited in shock tube.
文摘Follicle stimulating hormone (FSH) is a kind of glycoprotein gonadotropin, and plays an important role in the diagnosis and treatment of infertility. Follicle stimulating hormone receptor (FSHR) is a kind of G protein coupled receptor (GPCR), found in the ovary and testes, and its activation is required for the hormonal operation during the breeding period. In this study, an experimental model of FSHR mediated FSH into cell membrane, which exhibited a phenomenon of fluorescent localized on cell surfaces internalized into cell interior, was established to verify biological activity of FSH.
文摘To discuss the structure design and optimization of building curtain wall, the dynamic characteristics of point supported glass curtain wall system are analyzed by the finite element method. The various technologies are made use of, and according to the characteristics of the structure system, the finite element analysis model with steel structure glass plate beam element and shell element as the basic elements is established. Then, the dynamic characteristics are analyzed, and the modal parameters such as inherent frequency and vibration type are identified. The research results show that the node displacement response power spectrum under the load of wind is obtained, which provides the basis for rationally optimizing the structure. Based on the above findings, it is concluded that the optimization design based on finite element model has a wide significance, which is a useful attempt to reduce the blindness of design and has great engineering significance and application value.
基金supported by the National Key R&D Program of China (No.2021YFF1200900)National Natural Science Foundation of China (No.32170646,8197211)+5 种基金Guangdong Basic and Applied Basic Research Foundation (China) (No.2023A1515011908 to N.H.)Key-Area Research and Development Program of Guangdong Province,China (No.2023B1111020006)International Science and Technology CooperationnProgramnofGuangdong,China (No.2021A0505030011)Shenzhen Innovation Committee of Science and Technology (Guangdong,China) (No.JCYJ20220818100401003)Shenzhen Science and Technology Program (Guangdong,China) (No.SGDX20201103095800003,GJHZ20200731095606019,JCYJ20220818100401003)Shenzhen High-level Hospital Construction Fund (Guangdong,China) (No.1801004).
文摘Chondrocyte is considered the only cell type in cartilage.However,the cell hetero-geneity of chondrocytes in human articular cartilage is still not well defined,which hinders our understanding of the pathogenesis of osteoarthritis(OA).Here,we constructed a single-cell transcriptomic atlas of chondrocytes in healthy cartilage and identified nine chondrocyte sub-sets including homeostatic chondrocytes,proliferate fibrochondrocytes,and hypertrophic chondrocytes(HTC).Interestingly,we identified two distinct HTC subpopulations,among which HTC-1 specifically expressed genes associated with apoptosis and programmed cell death.We identified two main trajectories of chondrocytes,one of which differentiates into fibrochondrocytes,while the other terminates in apoptosis.Comparison of chondrocyte subsets between healthy and OA cartilage showed that proliferate fibrochondrocytes and HTC-1 expanded in OA patients,whereas homeostatic chondrocytes decreased.Interestingly,we discovered an OA-specific proliferate fibrochondrocyte subset that may contribute to the development of OA via inflammation.In summary,this study significantly enhanced our understanding of cell heterogeneity of chondrocytes in articular cartilage and provides insight into the pathogenesis of OA.
基金supported by the National key research and development program of China(2022YFC3602902,2022YFC3602901,2020YFC2008601)National Natural Science Foundation of China(Grant No.82160379)+2 种基金Programs from Science and Technology Department of Sichuan Province(2023NSFSC1906,2021YJ0462)National Clinical Research Center for Geriatrics,West China Hospital,Sichuan University(Z2023LC007,Z2024LC003)Postdoctoral Fellowship Program of CPSF(GZC20241158).
文摘Per-and polyfluoroalkyl substances(PFAS)are persistent environmental pollutants known for their bioaccumulative nature.Reduced bone mineral density(BMD)is associated with an increased risk of developing osteoporosis.This pioneering study aims to assess the effects of different PFAS compounds on bone mineral.We conducted searches on online databases.Inclusion criteria included the presence of associations between perfluorooctanoic acid(PFOA),perfluorooctanesulfonate(PFOS),perfluorohexanesulfonic acid(PFHxS),perfluorononanoic acid(PFNA),and perfluorodecanoic acid(PFDA)and BMD,BMD zscore,and bone mineral content(BMC).Meta-analyses were performed.Best evidence synthesis(BES)was performed to summarize the results.The results of BES showed that the evidence of PFOS,PFOA and PFNA with reduced bone mineral were moderate.The variability in methods for assessing bone mineral and sex differences are potential sources of heterogeneity in the results.Meta analysis showed that PFOA was associated with BMD(β−0.01,95%CI−0.01 to−0.00;I^(2)=0%).Subgroup analysis by sex showed that PFOS(β−0.01,95%CI−0.01 to−0.00;I^(2)=50%),PFOA(β−0.01,95%CI−0.01 to+0.00;I^(2)=29%)were negatively correlated with BMD.This systematic review and BES revealed negative correlations between exposure to PFOS,PFOA,PFNA and bone mineral.Sex emerged as a potential factor affecting the negative effects of PFAS on bone mineral.The damage of PFAS to bone mineral still requires further exploration.
