Foreign body reactions to the wear debris and corrosion products from the implants,and bacterial infections are the main factors leading to the implant failures.In order to resolve these problems,the antibacterial TiN...Foreign body reactions to the wear debris and corrosion products from the implants,and bacterial infections are the main factors leading to the implant failures.In order to resolve these problems,the antibacterial TiN/Cu nanocomposite coatings with various N_(2) partial pressures were deposited on 304 stainless steels(SS)using an arc ion plating(AIP)system,named TiN/Cu-x(x=0.5,1.0,1.5 Pa).The results of X-ray diffraction analysis,energy-dispersive X-ray spectroscopy,and scanning electron microscopy showed that the N_(2) partial pressures determined the Cu contents,surface defects,and crystallite sizes of TiN/Cu nanocomposite coatings,which further influenced the comprehensive abilities.And the hardness and wear resistances of TiN/Cu coatings were enhanced with increase of the crystallite sizes.Under the co-actions of surface defects,crystallite sizes,and Cu content,TiN/Cu-1.0 and TiN/Cu-1.5 coatings possessed excellent corrosion resistance.Besides,the biological tests proved that all the TiN/Cu coatings showed no cytotoxicity with strong antibacterial ability.Among them,TiN/Cu-1.5 coating significantly promoted the cell proliferation,which is expected to be a novel antibacterial,corrosion-resistant,and wear-resistant coating on the surfaces of medical implants.展开更多
Applications of process systems engineering(PSE)in plants and enterprises are boosting industrial reform from automation to digitization and intelligence.For ethylene thermal cracking,knowledge expression,numerical mo...Applications of process systems engineering(PSE)in plants and enterprises are boosting industrial reform from automation to digitization and intelligence.For ethylene thermal cracking,knowledge expression,numerical modeling and intelligent optimization are key steps for intelligent manufacturing.This paper provides an overview of progress and contributions to the PSE-aided production of thermal cracking;introduces the frameworks,methods and algorithms that have been proposed over the past10 years and discusses the advantages,limitations and applications in industrial practice.An entire set of molecular-level modeling approaches from feedstocks to products,including feedstock molecular reconstruction,reaction-network auto-generation and cracking unit simulation are described.Multilevel control and optimization methods are exhibited,including at the operational,cycle,plant and enterprise level.Relevant software packages are introduced.Finally,an outlook in terms of future directions is presented.展开更多
In paired Fermi systems,strong many-body effects exhibit in the crossover regime between the Bardeen–Cooper–Schrieffer(BCS)and the Bose–Einstein condensation(BEC)limits.The concept of the BCS–BEC crossover,which i...In paired Fermi systems,strong many-body effects exhibit in the crossover regime between the Bardeen–Cooper–Schrieffer(BCS)and the Bose–Einstein condensation(BEC)limits.The concept of the BCS–BEC crossover,which is studied intensively in the research field of cold atoms,has been extended to condensed matters.Here by analyzing the typical superconductors within the BCS–BEC phase diagram,we find that FeSe-based superconductors are prone to shift their positions in the BCS–BEC crossover regime by charge doping or substrate substitution,since their Fermi energies and the superconducting gap sizes are comparable.Especially at the interface of single-layer FeSe on SrTiO3 substrate,the superconductivity is relocated closer to the crossover unitary than other doped FeSe-based materials,indicating that the pairing interaction is effectively modulated.We further show that hole-doping can drive the interfacial system into the phase with possible pre-paired electrons,demonstrating its flexible tunability within the BCS–BEC crossover regime.展开更多
In order to explore the potential of profit margin improvement,a novel three-scale integrated optimization model of furnace simulation,cyclic scheduling,and supply chain of ethylene plants is proposed and evaluated.A ...In order to explore the potential of profit margin improvement,a novel three-scale integrated optimization model of furnace simulation,cyclic scheduling,and supply chain of ethylene plants is proposed and evaluated.A decoupling strategy is proposed for the solution of the three-scale model,which uses our previously proposed reactor scale model for operation optimization and then transfers the obtained results as a parameter table in the joint MILP optimization of plant-supply chain scale for cyclic scheduling.This optimization framework simplifies the fundamental mixed-integer nonlinear programming(MINLP)into several sub-models,and improves the interpretability and extendibility.In the evaluation of an industrial case,a profit increase at a percentage of 3.25%is attained in optimization compared to the practical operations.Further sensitivity analysis is carried out for strategy evolving study when price policy,supply chain,and production requirement parameters are varied.These results could provide useful suggestions for petrochemical enterprises on thermal cracking production.展开更多
Objective Telomere length, as an emerging marker of biological age,isrelatedwithhypertension.Ouraimistoinvestigatethe relationship between telomere trajectory and blood pressure change as well as the incident cardiova...Objective Telomere length, as an emerging marker of biological age,isrelatedwithhypertension.Ouraimistoinvestigatethe relationship between telomere trajectory and blood pressure change as well as the incident cardiovascular events in a longitudinal hypertensive cohort in China.展开更多
Background:Arterial stiffening increases with age and blood pressure and is associated with cardiovascular disease(CVD),but the relationship between blood pressure lowering and arterial stiffening is still uncertain,e...Background:Arterial stiffening increases with age and blood pressure and is associated with cardiovascular disease(CVD),but the relationship between blood pressure lowering and arterial stiffening is still uncertain,especially in older people.This study aimed to evaluate the effect of intensive blood pressure treatment on the progression of arterial stiffness and risk of CVD in older patients with hypertension.Methods:The Strategy of Blood Pressure Intervention in the Elderly Hypertensive Patients(STEP)trial was a multicenter,randomized,controlled trial performed at 42 clinical centers throughout China,and 8511 patients aged 60-80 years with essential hypertension were enrolled and randomly assigned to systolic blood pressure(SBP)target of 110 mmHg to<130 mmHg(intensive treatment)or 130 mmHg to<150 mmHg(standard treatment).Patients underwent repeated examinations of the brachial-ankle pulse wave velocity(baPWV)and ankle-brachial index(ABI)at baseline,and the arterial stiffness was evaluated at the 3-year follow-up.A total of 5339 patients who had twice repeated measurements were included in this study.Changes in arterial stiffness between the intensive and standard treatment groups were analyzed using a multivariate linear regression model.The Cox proportional hazard regression model was used to evaluate the effect of intensive treatment on primary CVD outcomes.Results:The changes in baPWV were 61.5 cm/s(95%confidence interval[CI]:49.8-73.2 cm/s)in the intensive treatment group and 98.4 cm/s(95%CI:86.7-110.1 cm/s)in the standard treatment group(P<0.001).Intensive treatment significantly delayed the progression of arterial stiffness,with an annual change of 23.1 cm·s^(-1)·year-1 vs.36.7 cm·s^(-1)·year^(-1)of baPWV in the intensive and standard treatment groups,respectively.During a median follow-up period of 3.36 years,primary CVD outcomes occurred in 77(2.9%)patients in the intensive treatment group compared with 93(3.5%)in the standard treatment group.Intensive treatment resulted in a significantly lower CVD risk in patients aged 70-80 years or with SBP<140 mmHg.Conclusion:Intensive blood pressure control with an SBP target of 110 mmHg to<130 mmHg could delay the progression of arterial stiffness and reduce the risk of CVD in older patients with hypertension.Clinical trial registration:http://www.clinicaltrials.gov;No.NCT03015311.展开更多
This study used an anodic etching(AE)method to construct a hierarchical rough surface on the surface of the Cu-bearing antibacterial titanium alloy,Ti-xCu(x=3,5,7 wt%),a three-dimensional structure with nested micro-/...This study used an anodic etching(AE)method to construct a hierarchical rough surface on the surface of the Cu-bearing antibacterial titanium alloy,Ti-xCu(x=3,5,7 wt%),a three-dimensional structure with nested micro-/submicro-pores and internal cavities,which is conducive to the adhesion and growth of bone cells.After AE treatment,with increase of the Cu content in the alloy,the surface of Ti-Cu alloy became sharper,with more fine micropores and internal cavities,thus increasing the surface area.The results indicated that the AE/Ti-Cu alloy exhibited good antibacterial properties and had the effect of inhibiting bacterial biofilm formation.AE treatment could increase the Cu ions release of Ti-Cu alloy in saline,and the higher the Cu content in the alloy,the more Cu ions release,resulting in stronger antibacterial performance of the alloy.AE/Ti-Cu alloy showed excellent biocompatibility,similar to the pure Ti.Therefore,anodic etching is a safe and effective surface treatment method for Ti-Cu alloy,with good clinical application prospects.展开更多
To the Editor:The global burden of premature coronary artery disease(CAD)is increasing among the young population.Premature CAD generally refers to the occurrence of obstructive coronary atherothrombotic lesions in me...To the Editor:The global burden of premature coronary artery disease(CAD)is increasing among the young population.Premature CAD generally refers to the occurrence of obstructive coronary atherothrombotic lesions in men and women aged<55 years and<65 years,respectively,and particularly in those aged<45 years.[1]The incidence of CAD in the younger population has remained stable or has increased,despite the declining incidence in older adults.Patients with premature CAD have a poor long-term prognosis,experiencing a high rate of recurrent ischemic events,rapid progression to multivessel disease,and frequent premature death.[1]Thus,it is crucial to identify the underlying causes of premature CAD that are distinct from those of age-related CAD and improve patient outcomes through precise diagnosis and treatment.展开更多
In this work,the microbiologically influenced corrosion(MIC)of Fe_(40)(CoCrMnNi)_(60) and Fe_(60)(CoCrMnNi)_(40) medium entropy alloys(MEAs)induced by Pseudomonas aeruginosa(P.aeruginosa)was investigated.Corrosion beh...In this work,the microbiologically influenced corrosion(MIC)of Fe_(40)(CoCrMnNi)_(60) and Fe_(60)(CoCrMnNi)_(40) medium entropy alloys(MEAs)induced by Pseudomonas aeruginosa(P.aeruginosa)was investigated.Corrosion behaviors during 14 days of immersion in sterile and P.aeruginosa-inoculated culture media are presented.Under sterile conditions,both MEAs exhibited good corrosion resistance against the culture medium solution.In the presence of P.aeruginosa,the pitting corrosion of MEAs was promoted.The results of inductively coupled plasma‒mass spectrometry(ICP‒MS)and potentiodynamic polarization tests showed that the presence of P.aeruginosa promoted the selective dissolution of passive film and accelerated the corrosion of MEAs.The results of X-ray photoelectron spectroscopy(XPS)and Mott-Schottky measurements further demonstrated the degradation effect of P.aeruginosa on the passive film.Compared with Fe_(60)(CoCrMnNi)_(40),Fe_(40)(CoCrMnNi)_(60) manifested better resistance to the MIC caused by P.aeruginosa,which may be attributed to more Cr oxides and fewer Fe oxides of the passive film.展开更多
Grain refinement has been found to be able to improve the strength of metals without reducing their plasticity or ductility.In this work,ultrafine-grained Ti6Al7Nb-xCu(x=0,3 wt%,6 wt%,9 wt%)alloys were fabricated base...Grain refinement has been found to be able to improve the strength of metals without reducing their plasticity or ductility.In this work,ultrafine-grained Ti6Al7Nb-xCu(x=0,3 wt%,6 wt%,9 wt%)alloys were fabricated based on the clinically used Ti6Al7Nb alloy via Cu alloying fabrication strategy combined with dynamic recrystallization(DRX)from martensite during hot work.Our results indicate that Cu alloying is not only effective in reducing the width of martensite laths after quenching in theβphase region but also increases the nucleation rate of DRX during the high-temperature deformation.Additionally,the Ti2Cu phase that precipitates from the matrix can pin the grain boundaries and inhibit their growth during the high-temperature deformation.The optimal Cu concentration of Ti6Al7Nb-xCu alloy is determined to be 6 wt%,and the optimal deformation temperature is determined to be 750°C.At this Cu content and deformation temperature,the grain size is only 270 nm,the tensile strength is up to 1266±10 MPa,and the elongation is 17%.Compared with the commercial Ti6Al7Nb alloy,the ultrafine-grained Ti6Al7Nb-6Cu alloy has better overall mechanical properties,good biocompatibility,and unique antibacterial properties.This work provides a theoretical basis for fabricating the new antibacterial titanium-based alloys with high strength.展开更多
Ti-Cu alloys with different Cu contents(3, 5 and 7 wt%) were fabricated and studied as novel antibacterial biomaterials for dental application. The Ti-Cu alloys were annealing treated at different temperatures(740℃, ...Ti-Cu alloys with different Cu contents(3, 5 and 7 wt%) were fabricated and studied as novel antibacterial biomaterials for dental application. The Ti-Cu alloys were annealing treated at different temperatures(740℃, 830℃ and 910℃) in order to obtain three typical microstructures, β-Ti + Ti2Cu, β-Ti + transformed α-Ti, and transformed α-Ti. Mechanical, antibacterial and biocorrosion properties of Ti-Cu alloys with different microstructures were well analyzed by scanning electron microscopy(SEM),X-ray diffraction(XRD), transmission electron microscopy(TEM), tensile test, electrochemical test and antibacterial test. The results indicated that the Ti-Cu alloys with microstructure of β-Ti + Ti2 Cu showed the best ductility compared with other Ti-Cu alloys with microstructures of β-Ti + transformed α-Ti and complete transformed α-Ti, and meanwhile, increase of the Cu content significantly contributed to the decreased ductility due to the increasing amount of Ti2 Cu, which brought both solid solution strengthening and precipitation strengthening. Finally, the Ti-5 Cu alloy with microstructure of β-Ti + Ti2 Cu exhibited excellent ductility, antibacterial property and corrosion resistance, providing a great potential in clinical application for dental implants.展开更多
Entosis, a ceU-in-ceU process, has been implicated in the formation of aneuploidy associated with an aberrant cell division control. Microtubule plus-end-tracking protein TI P150 facilitates the loading of MCAK onto t...Entosis, a ceU-in-ceU process, has been implicated in the formation of aneuploidy associated with an aberrant cell division control. Microtubule plus-end-tracking protein TI P150 facilitates the loading of MCAK onto the microtubule plus ends and orchestrates micro- tubule plus-end dynamics during cell division. Here we show that TIP150 cooperates with MCAK to govern entosis via a regulatory cir- cuitry that involves Aurora A-mediated phosphorylation of MCAK. Our biochemical analyses show that MCAK forms an intra-molecular association, which is essential for TIP150 binding. Interestingly, Aurora A-mediated phosphorylation of MCAK modulates its intra-mo- lecular association, which perturbs the MCAK-TI P150 interaction in vitro and inhibits entosis in vivo. To probe if MCAK-TIP150 inter- action regulates microtubule plasticity to affect the mechanical properties of ceUs during entosis, we used an optical trap to measure the mechanical rigidity of live MCF7 ceils. We find that the MCAK cooperates with TIP150 to promote microtubule dynamics and modulate the mechanical rigidity of the cells during entosis. Our results show that a dynamic interaction of MCAK-TI P150 orchestrated by Aurora A-mediated phosphorylation governs entosis via regulating microtubule plus-end dynamics and cell rigidity. These data reveal a previously unknown mechanism of Aurora A regulation in the control of microtubule plasticity during ceU-in-ceU pro- cesses.展开更多
Implant-related infection and early bone integration are the main risk factors of implants for long-term service,to overcome these difficulties,SLA-TiCu surface was prepared by sandblasting and large-grits etching(SLA...Implant-related infection and early bone integration are the main risk factors of implants for long-term service,to overcome these difficulties,SLA-TiCu surface was prepared by sandblasting and large-grits etching(SLA)treatment on a novel antibacterial titanium-copper alloy(TiCu),which is the most prevalent surface treatment with micro/submicron hierarchical structures to titanium-based implants.Effects of SLA-TiCu surface on the adhesion,proliferation,apoptosis and differentiation of MC3T3-E1 cells as well as the antibacterial activity against a common orthopedic pathogen(Staphylococcus aureus)were studied.Compared to the following surfaces:sandblasting and large-grits etched pure titanium(SLATi),mechanically ground pure titanium and TiCu alloy(M-Ti and M-TiCu),these results indicated that SLA-TiCu surface obviously enhanced the bone-related gene expressions(alkaline phosphates(ALP),collagen typeⅠ(COLⅠ),Runt-related transcription factor 2(RUN x 2),and osteopontin(OPN)).Moreover,SLA-TiCu surface could maintain a sustainable release of Cu2+ions and effectively inhibited the viability of bacteria.This study demonstrated that SLA-TiCu surface possessed multifunctional characteristics of improved osteogenic ability and antibacterial activity,making it promising as a novel implant material for hard tissue repairs such as orthopedics and dental implants.展开更多
The Ti6Al4V-Cu alloy was reported to show good antibacterial properties, which was promising to reduce the hazard of the bacterial infection problem. For the purpose of preparing Ti6Al4V-Cu alloy with satisfied compre...The Ti6Al4V-Cu alloy was reported to show good antibacterial properties, which was promising to reduce the hazard of the bacterial infection problem. For the purpose of preparing Ti6Al4V-Cu alloy with satisfied comprehensive properties, it’s important to study the heat treatment and the appropriate Cu content of the alloy. In this study, high Cu content Ti6Al4V-x Cu(x = 4.5, 6, 7.5 wt%) alloys were prepared, and firstly the annealing heat treatments were optimized in the α+β+Ti2Cu triple phase region to obtain satisfied tensile mechanical properties. Then the effect of Cu content on the tribological property, corrosion resistance, antibacterial activity and cytotoxicity of the Ti6Al4 V-x Cu alloys were systematically studied to obtain the appropriate Cu content. The results showed that the optimal annealing temperatures for Ti6Al4 V-x Cu(x = 4.5, 6, 7.5 wt%) alloys were 720, 740 and 760℃, respectively, which was resulted from the proper volume fractions of α,β and Ti2Cu phases in the microstructure. The additions of 4.5 wt% and 6 wt% Cu into the medical Ti6Al4 V alloy could enhance the wear resistance and corrosion resistance of the alloy, but the addition of 7.5 wt% Cu showed an opposite effect. With the increase of the Cu content, the antibacterial property was enhanced due to the increased volume fraction of Ti2Cu phase in the microstructure, but when the Cu content was increased to 7.5 wt%, cytotoxicity was presented. A medium Cu content of 6 wt%, with annealing temperature of 740℃ make the alloy possesses the best comprehensive properties of tensile properties, wear resistance, corrosion resistance, antibacterial property and biocompatibility, which is promising for future medical applications.展开更多
Ti-15 Zr-xCu(3≤x≤7,wt.%) novel antibacterial and antibiofilm alloys with competitive mechanical properties,biological responses and corrosion resistance were designed and fabricated.Annealing heat treatment on Ti-15...Ti-15 Zr-xCu(3≤x≤7,wt.%) novel antibacterial and antibiofilm alloys with competitive mechanical properties,biological responses and corrosion resistance were designed and fabricated.Annealing heat treatment on Ti-15 Zr-7 Cu(TZC-7 A),after holding for 2 h at slightly above their beta transus temperature(BTT) ensured their tensile strength(UTS),yield strength(YS) and hardness(HRV) were improved by31.2%,20% and 12.3% respectively compared to the control without Cu,Ti-15 Zr(T-15 ZA).Although the3 wt.% Cu alloy displayed the highest elongation(26%),the TZC-7 A alloy also possessed a good ductility.Presence of evenly dispersed Ti2 Cu and Zr2 Cu Cu-rich intermetallic phases formed as interwoven and alternating lamellae within the α+β matrix as a result of Cu addition,as revealed by X-ray diffraction(XRD),scanning electron microscopy(SEM) and transmission electron microscopy(TEM).These greatly contributed to their strengthening and bactericidal properties.Over 98% antibacterial effect against E.coli and S.aureus have been imparted,coupled with excellent biofilm inhibition.Potentiodynamic polarization curves showed that the TZC-7 A alloy possessed higher corrosion resistance than commercially pure titanium,cp-Ti;contact angle test revealed enhanced hydrophilicity;while confocal laser scanning microscopy(CLSM) and cell counting kit(CCK-8) assays also displayed drastically lowered bacterial adhesion rate with comparatively no cytotoxicity.Cell attachment on all alloys was similar but the best spread was obtained on TZC-7 A after 24 h.The developed alloy has good potential as an antibacterial implant material with combination of optimized properties.展开更多
In order to reduce implant-related infections and improve early osseointegration,we performed HF+anodic oxidation on the surface of the new antibacterial Ti-Cu alloy to make the titanium-based implants have a micro/su...In order to reduce implant-related infections and improve early osseointegration,we performed HF+anodic oxidation on the surface of the new antibacterial Ti-Cu alloy to make the titanium-based implants have a micro/submicron structure.On this basis,a series of surface-modified Ti-x Cu alloys with different Cu contents(3,5 and 7 wt%)were fabricated and a comprehensive study was conducted on MC3 T3-E1 cell adhesion,proliferation,apoptosis and its antibacterial activity against Staphylococcus aureus.Results showed that the Ti-x Cu alloys by HF etching+anodized possessed multifunctional characteristics of antibiofilm and antibacterial abilities,excellent biocompatibility and osteogenesis promoting abilities.Increment of Cu content significantly contributed to the antibacterial and osteogenic properties of HF etching+anodized Ti-Cu alloys.Cell proliferation rates of HF etching+anodized Ti-7 Cu alloys were lower than those of Ti-3 Cu and Ti-5 Cu alloys,while the early cell apoptosis rates were higher than Ti-3 Cu and Ti-5 Cu groups.All the above results finally presented that the HF etching+anodized Ti-5 Cu alloy exhibited extremely strong antibacterial properties,good biological compatibility and osteogenic ability,as well as the most excellent ductility and corrosion resistance,providing a great potential application for the future dental implantation.展开更多
The adsorption behavior, antibacterial, and corrosion properties of a Ti-3 Cu alloy were studied in a phosphate-buffered saline solution containing 0, 1, 3, and 6 gL^(-1) bovine serum albumin protein at 37℃ and pH = ...The adsorption behavior, antibacterial, and corrosion properties of a Ti-3 Cu alloy were studied in a phosphate-buffered saline solution containing 0, 1, 3, and 6 gL^(-1) bovine serum albumin protein at 37℃ and pH = 7.4(±0.2). The protein adsorption behavior was examined via cyclic voltammetry, secondary ions mass spectroscopy(SIMS), and angle-resolved X-ray photoelectron spectroscopy(ARXPS). The corrosion property was analyzed by the open circuit potential(OCP), potentiodynamic polarization(PD),and electrochemical impedance spectroscopy(EIS) examinations. The antibacterial test was conducted according to the GB/T 21510 China Standard. It was observed that the surface charge density(QA DS) was directly proportional to the amount of the adsorbed BSA protein, signifying that the protein adsorption was accompanied by the charge transfer, pointing to chemisorptions phenomena. BSA amino groups and other organic species were observed in the surface analysis examinations. It was shown that the formation of barrier complexes between the TiO_(2) oxide-layer and PBS solution resulted in decreasing the release of Cu-ions, which consequently reduced the antibacterial activity. On the other hand, these barrier complexes improved the corrosion resistance by increasing the charge transfer resistance and double-layer capacitance of the Ti-3 Cu alloy.展开更多
This work was focused on study of anti-infection ability and its underlying mechanism of a novel dental implant made of titanium-copper(TiCu)alloy.In general,most studies on antibacterial implants have used a single p...This work was focused on study of anti-infection ability and its underlying mechanism of a novel dental implant made of titanium-copper(TiCu)alloy.In general,most studies on antibacterial implants have used a single pathogen to test their anti-infection ability using infectious animal models.However,dental implant-associated infections are polymicrobial diseases.We innovatively combine the classic ligature model in dogs with sucrose-rich diets to induce oral infections via the canine native oral bacteria.The anti-infection ability,biocompatibility and underlying mechanism of TiCu implant were systematically investigated in comparison with pure Ti implant via general inspection,hematology,imageology(micro-CT),microbiology(16S rDNA and metagenome),histology,and Cu ion detections.Compared with Ti implant,TiCu implant demonstrated remarkable anti-infection potentials with excellent biocompatibility.Additionally,the underlying anti-infection mechanism of TiCu implant was considered to involve maintaining the oral microbiota homeostasis.It was found that the carbohydrates in the plaques formed on the surface of TiCu implant were metabolized through the tricarboxylic acid cycle(TCA)cycles,which prevented the formation of an acidic microenvironment and inhibited the accumulation of acidogens and pathogens,thereby maintaining the microflora balance between aerobic and anaerobic bacteria.展开更多
The effects of different aging conditions on the microstructure,strength,corrosion resistance,cytotoxicity and antibacterial ability of Ti-15Zr-xCu(3≤x≤7,wt%)(TZC)alloys were systematically investigated.Microstructu...The effects of different aging conditions on the microstructure,strength,corrosion resistance,cytotoxicity and antibacterial ability of Ti-15Zr-xCu(3≤x≤7,wt%)(TZC)alloys were systematically investigated.Microstructural evolution and behavior were analyzed by X-ray diffraction(XRD)patterns and scanning electron microscopy with energy-dispersive spectroscopy(SEM-EDS),while potentiodynamic polarization technique was employed to characterize the corrosion response of the alloys after solution-treatment and aging(STA).High-temperature aging at 660℃ for 4 h(660-4)gave the best combination of properties by enabling significant precipitation of the Cu-rich Ti_(2)Cu and Zr_(2)Cu compounds,and mild formation of the Zr_(7)Cu_(10) secondary phase.The high kinetics at this condition was beneficial to the complete precipitation and more homogeneous distribution of the intermetallic particles.These led to the inhibition of dislocation movements and allowed for significantly improved mechanical strengths with added ductility,availability of more Cu ions for the desired oligodynamic activity without evoking cytotoxicity,better corrosion resistance and very high antibacterial ability(over 99.5%),thus improving the overall properties of the TZC alloys for biomedical applications.展开更多
基金financially supported by National Key Research and Development Program of China (Nos. 2018YFC1106601 and 2016YFC1100601)Liaoning Revitalization Talents Program (No. XLYC1807069)+1 种基金National Natural Science Foundation of China (Nos. 51631009 and 31870954)Key Projects for Foreign Cooperation of Bureau of International Cooperation Chinese Academy of Sciences (No. 174321KYSB20180006)
文摘Foreign body reactions to the wear debris and corrosion products from the implants,and bacterial infections are the main factors leading to the implant failures.In order to resolve these problems,the antibacterial TiN/Cu nanocomposite coatings with various N_(2) partial pressures were deposited on 304 stainless steels(SS)using an arc ion plating(AIP)system,named TiN/Cu-x(x=0.5,1.0,1.5 Pa).The results of X-ray diffraction analysis,energy-dispersive X-ray spectroscopy,and scanning electron microscopy showed that the N_(2) partial pressures determined the Cu contents,surface defects,and crystallite sizes of TiN/Cu nanocomposite coatings,which further influenced the comprehensive abilities.And the hardness and wear resistances of TiN/Cu coatings were enhanced with increase of the crystallite sizes.Under the co-actions of surface defects,crystallite sizes,and Cu content,TiN/Cu-1.0 and TiN/Cu-1.5 coatings possessed excellent corrosion resistance.Besides,the biological tests proved that all the TiN/Cu coatings showed no cytotoxicity with strong antibacterial ability.Among them,TiN/Cu-1.5 coating significantly promoted the cell proliferation,which is expected to be a novel antibacterial,corrosion-resistant,and wear-resistant coating on the surfaces of medical implants.
基金The authors gratefully acknowledge the National Natural Science Foundation of China for its financial support(U1462206).
文摘Applications of process systems engineering(PSE)in plants and enterprises are boosting industrial reform from automation to digitization and intelligence.For ethylene thermal cracking,knowledge expression,numerical modeling and intelligent optimization are key steps for intelligent manufacturing.This paper provides an overview of progress and contributions to the PSE-aided production of thermal cracking;introduces the frameworks,methods and algorithms that have been proposed over the past10 years and discusses the advantages,limitations and applications in industrial practice.An entire set of molecular-level modeling approaches from feedstocks to products,including feedstock molecular reconstruction,reaction-network auto-generation and cracking unit simulation are described.Multilevel control and optimization methods are exhibited,including at the operational,cycle,plant and enterprise level.Relevant software packages are introduced.Finally,an outlook in terms of future directions is presented.
基金Supported by the National Key R&D Program of China under Grant Nos 2017YFA0303600,2016YFA0300600 and2016YFA0202300the National Natural Science Foundation of China under Grant No 11634016+3 种基金the Strategic Priority Research Program(B)of Chinese Academy of Sciences under Grant No XDB07030100the Research Program of Beijing Academy of Quantum Information Sciences under Grant No Y18G09the Youth Innovation Promotion Association of Chinese Academy of Sciences under Grant No 2016008the Hundred Talents Program of Chinese Academy of Sciences
文摘In paired Fermi systems,strong many-body effects exhibit in the crossover regime between the Bardeen–Cooper–Schrieffer(BCS)and the Bose–Einstein condensation(BEC)limits.The concept of the BCS–BEC crossover,which is studied intensively in the research field of cold atoms,has been extended to condensed matters.Here by analyzing the typical superconductors within the BCS–BEC phase diagram,we find that FeSe-based superconductors are prone to shift their positions in the BCS–BEC crossover regime by charge doping or substrate substitution,since their Fermi energies and the superconducting gap sizes are comparable.Especially at the interface of single-layer FeSe on SrTiO3 substrate,the superconductivity is relocated closer to the crossover unitary than other doped FeSe-based materials,indicating that the pairing interaction is effectively modulated.We further show that hole-doping can drive the interfacial system into the phase with possible pre-paired electrons,demonstrating its flexible tunability within the BCS–BEC crossover regime.
基金the National Natural Science Foundation of China for its financial support(U1462206,21991100,21991104)。
文摘In order to explore the potential of profit margin improvement,a novel three-scale integrated optimization model of furnace simulation,cyclic scheduling,and supply chain of ethylene plants is proposed and evaluated.A decoupling strategy is proposed for the solution of the three-scale model,which uses our previously proposed reactor scale model for operation optimization and then transfers the obtained results as a parameter table in the joint MILP optimization of plant-supply chain scale for cyclic scheduling.This optimization framework simplifies the fundamental mixed-integer nonlinear programming(MINLP)into several sub-models,and improves the interpretability and extendibility.In the evaluation of an industrial case,a profit increase at a percentage of 3.25%is attained in optimization compared to the practical operations.Further sensitivity analysis is carried out for strategy evolving study when price policy,supply chain,and production requirement parameters are varied.These results could provide useful suggestions for petrochemical enterprises on thermal cracking production.
文摘Objective Telomere length, as an emerging marker of biological age,isrelatedwithhypertension.Ouraimistoinvestigatethe relationship between telomere trajectory and blood pressure change as well as the incident cardiovascular events in a longitudinal hypertensive cohort in China.
基金supported by grants from the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(Nos.2016-I2M-1-006 and 2021-I2M-1-011)
文摘Background:Arterial stiffening increases with age and blood pressure and is associated with cardiovascular disease(CVD),but the relationship between blood pressure lowering and arterial stiffening is still uncertain,especially in older people.This study aimed to evaluate the effect of intensive blood pressure treatment on the progression of arterial stiffness and risk of CVD in older patients with hypertension.Methods:The Strategy of Blood Pressure Intervention in the Elderly Hypertensive Patients(STEP)trial was a multicenter,randomized,controlled trial performed at 42 clinical centers throughout China,and 8511 patients aged 60-80 years with essential hypertension were enrolled and randomly assigned to systolic blood pressure(SBP)target of 110 mmHg to<130 mmHg(intensive treatment)or 130 mmHg to<150 mmHg(standard treatment).Patients underwent repeated examinations of the brachial-ankle pulse wave velocity(baPWV)and ankle-brachial index(ABI)at baseline,and the arterial stiffness was evaluated at the 3-year follow-up.A total of 5339 patients who had twice repeated measurements were included in this study.Changes in arterial stiffness between the intensive and standard treatment groups were analyzed using a multivariate linear regression model.The Cox proportional hazard regression model was used to evaluate the effect of intensive treatment on primary CVD outcomes.Results:The changes in baPWV were 61.5 cm/s(95%confidence interval[CI]:49.8-73.2 cm/s)in the intensive treatment group and 98.4 cm/s(95%CI:86.7-110.1 cm/s)in the standard treatment group(P<0.001).Intensive treatment significantly delayed the progression of arterial stiffness,with an annual change of 23.1 cm·s^(-1)·year-1 vs.36.7 cm·s^(-1)·year^(-1)of baPWV in the intensive and standard treatment groups,respectively.During a median follow-up period of 3.36 years,primary CVD outcomes occurred in 77(2.9%)patients in the intensive treatment group compared with 93(3.5%)in the standard treatment group.Intensive treatment resulted in a significantly lower CVD risk in patients aged 70-80 years or with SBP<140 mmHg.Conclusion:Intensive blood pressure control with an SBP target of 110 mmHg to<130 mmHg could delay the progression of arterial stiffness and reduce the risk of CVD in older patients with hypertension.Clinical trial registration:http://www.clinicaltrials.gov;No.NCT03015311.
基金financially supported by the Natural Science Foundation of Liaoning Province(No.2022-MS-079).
文摘This study used an anodic etching(AE)method to construct a hierarchical rough surface on the surface of the Cu-bearing antibacterial titanium alloy,Ti-xCu(x=3,5,7 wt%),a three-dimensional structure with nested micro-/submicro-pores and internal cavities,which is conducive to the adhesion and growth of bone cells.After AE treatment,with increase of the Cu content in the alloy,the surface of Ti-Cu alloy became sharper,with more fine micropores and internal cavities,thus increasing the surface area.The results indicated that the AE/Ti-Cu alloy exhibited good antibacterial properties and had the effect of inhibiting bacterial biofilm formation.AE treatment could increase the Cu ions release of Ti-Cu alloy in saline,and the higher the Cu content in the alloy,the more Cu ions release,resulting in stronger antibacterial performance of the alloy.AE/Ti-Cu alloy showed excellent biocompatibility,similar to the pure Ti.Therefore,anodic etching is a safe and effective surface treatment method for Ti-Cu alloy,with good clinical application prospects.
基金supported by grants from the National Key Research and Development Program of China(Nos.2022YFC2703100,2020YFC0861000,and 2016YFC0901500)National Natural Science Foundation(No.82170486)+1 种基金Beijing Natural Science Foundation(No.L202046)CAMS Innovation Fund for Medical Sciences(Nos.2021-I2M-1-003 and 2017-I2M-2-001),and Center for Rare Diseases Research,Chinese Academy of Medical Sciences,Beijing,China.
文摘To the Editor:The global burden of premature coronary artery disease(CAD)is increasing among the young population.Premature CAD generally refers to the occurrence of obstructive coronary atherothrombotic lesions in men and women aged<55 years and<65 years,respectively,and particularly in those aged<45 years.[1]The incidence of CAD in the younger population has remained stable or has increased,despite the declining incidence in older adults.Patients with premature CAD have a poor long-term prognosis,experiencing a high rate of recurrent ischemic events,rapid progression to multivessel disease,and frequent premature death.[1]Thus,it is crucial to identify the underlying causes of premature CAD that are distinct from those of age-related CAD and improve patient outcomes through precise diagnosis and treatment.
基金financially supported by the National Natural Science Foundation of China(Nos.52001021,52161160308)the China Postdoctoral Science Foundation(Nos.2021M700372 and 2021M700381)+1 种基金the Joint Fund of Basic and Applied Basic Research Fund of Guangdong Province(No.2021B1515130009)the Open Fund from State Key Laboratory of Metal Material for Marine Equipment and Application(No.SKLMEA-K202006).
文摘In this work,the microbiologically influenced corrosion(MIC)of Fe_(40)(CoCrMnNi)_(60) and Fe_(60)(CoCrMnNi)_(40) medium entropy alloys(MEAs)induced by Pseudomonas aeruginosa(P.aeruginosa)was investigated.Corrosion behaviors during 14 days of immersion in sterile and P.aeruginosa-inoculated culture media are presented.Under sterile conditions,both MEAs exhibited good corrosion resistance against the culture medium solution.In the presence of P.aeruginosa,the pitting corrosion of MEAs was promoted.The results of inductively coupled plasma‒mass spectrometry(ICP‒MS)and potentiodynamic polarization tests showed that the presence of P.aeruginosa promoted the selective dissolution of passive film and accelerated the corrosion of MEAs.The results of X-ray photoelectron spectroscopy(XPS)and Mott-Schottky measurements further demonstrated the degradation effect of P.aeruginosa on the passive film.Compared with Fe_(60)(CoCrMnNi)_(40),Fe_(40)(CoCrMnNi)_(60) manifested better resistance to the MIC caused by P.aeruginosa,which may be attributed to more Cr oxides and fewer Fe oxides of the passive film.
基金financially supported by the National Key Research and Development Program of China(No.2022YFC2406003)the Bintech-IMR R&D Program(No.GYY-JSBU-2022-008).
文摘Grain refinement has been found to be able to improve the strength of metals without reducing their plasticity or ductility.In this work,ultrafine-grained Ti6Al7Nb-xCu(x=0,3 wt%,6 wt%,9 wt%)alloys were fabricated based on the clinically used Ti6Al7Nb alloy via Cu alloying fabrication strategy combined with dynamic recrystallization(DRX)from martensite during hot work.Our results indicate that Cu alloying is not only effective in reducing the width of martensite laths after quenching in theβphase region but also increases the nucleation rate of DRX during the high-temperature deformation.Additionally,the Ti2Cu phase that precipitates from the matrix can pin the grain boundaries and inhibit their growth during the high-temperature deformation.The optimal Cu concentration of Ti6Al7Nb-xCu alloy is determined to be 6 wt%,and the optimal deformation temperature is determined to be 750°C.At this Cu content and deformation temperature,the grain size is only 270 nm,the tensile strength is up to 1266±10 MPa,and the elongation is 17%.Compared with the commercial Ti6Al7Nb alloy,the ultrafine-grained Ti6Al7Nb-6Cu alloy has better overall mechanical properties,good biocompatibility,and unique antibacterial properties.This work provides a theoretical basis for fabricating the new antibacterial titanium-based alloys with high strength.
基金financially supported by the National Natural Science Foundation of China (Nos. 51631009 and 51811530320)the National Key Research and Development Program of China (Nos. 2018YFC1106600 and 2016YFC1100600)+1 种基金the Innovation Fund Project of Institute of Metal Research, Chinese Academy of Sciences (No. 2017-ZD01)the Key Projects for Foreign Cooperation of Bureau of International Cooperation Chinese Academy of Sciences (No. 174321KYSB2018000)
文摘Ti-Cu alloys with different Cu contents(3, 5 and 7 wt%) were fabricated and studied as novel antibacterial biomaterials for dental application. The Ti-Cu alloys were annealing treated at different temperatures(740℃, 830℃ and 910℃) in order to obtain three typical microstructures, β-Ti + Ti2Cu, β-Ti + transformed α-Ti, and transformed α-Ti. Mechanical, antibacterial and biocorrosion properties of Ti-Cu alloys with different microstructures were well analyzed by scanning electron microscopy(SEM),X-ray diffraction(XRD), transmission electron microscopy(TEM), tensile test, electrochemical test and antibacterial test. The results indicated that the Ti-Cu alloys with microstructure of β-Ti + Ti2 Cu showed the best ductility compared with other Ti-Cu alloys with microstructures of β-Ti + transformed α-Ti and complete transformed α-Ti, and meanwhile, increase of the Cu content significantly contributed to the decreased ductility due to the increasing amount of Ti2 Cu, which brought both solid solution strengthening and precipitation strengthening. Finally, the Ti-5 Cu alloy with microstructure of β-Ti + Ti2 Cu exhibited excellent ductility, antibacterial property and corrosion resistance, providing a great potential in clinical application for dental implants.
文摘Entosis, a ceU-in-ceU process, has been implicated in the formation of aneuploidy associated with an aberrant cell division control. Microtubule plus-end-tracking protein TI P150 facilitates the loading of MCAK onto the microtubule plus ends and orchestrates micro- tubule plus-end dynamics during cell division. Here we show that TIP150 cooperates with MCAK to govern entosis via a regulatory cir- cuitry that involves Aurora A-mediated phosphorylation of MCAK. Our biochemical analyses show that MCAK forms an intra-molecular association, which is essential for TIP150 binding. Interestingly, Aurora A-mediated phosphorylation of MCAK modulates its intra-mo- lecular association, which perturbs the MCAK-TI P150 interaction in vitro and inhibits entosis in vivo. To probe if MCAK-TIP150 inter- action regulates microtubule plasticity to affect the mechanical properties of ceUs during entosis, we used an optical trap to measure the mechanical rigidity of live MCF7 ceils. We find that the MCAK cooperates with TIP150 to promote microtubule dynamics and modulate the mechanical rigidity of the cells during entosis. Our results show that a dynamic interaction of MCAK-TI P150 orchestrated by Aurora A-mediated phosphorylation governs entosis via regulating microtubule plus-end dynamics and cell rigidity. These data reveal a previously unknown mechanism of Aurora A regulation in the control of microtubule plasticity during ceU-in-ceU pro- cesses.
基金financially supported by the National Key Research and Development Program of China(2018YFC1106601,2016YFC1100601)Liao Ning Revitalization Talents Program(XLYC1807069)+1 种基金National Natural Science Foundation(No.51631009,31870954)Key Projects for Foreign Cooperation of Bureau of International Cooperation Chinese Academy of Sciences(174321KYSB2018000)。
文摘Implant-related infection and early bone integration are the main risk factors of implants for long-term service,to overcome these difficulties,SLA-TiCu surface was prepared by sandblasting and large-grits etching(SLA)treatment on a novel antibacterial titanium-copper alloy(TiCu),which is the most prevalent surface treatment with micro/submicron hierarchical structures to titanium-based implants.Effects of SLA-TiCu surface on the adhesion,proliferation,apoptosis and differentiation of MC3T3-E1 cells as well as the antibacterial activity against a common orthopedic pathogen(Staphylococcus aureus)were studied.Compared to the following surfaces:sandblasting and large-grits etched pure titanium(SLATi),mechanically ground pure titanium and TiCu alloy(M-Ti and M-TiCu),these results indicated that SLA-TiCu surface obviously enhanced the bone-related gene expressions(alkaline phosphates(ALP),collagen typeⅠ(COLⅠ),Runt-related transcription factor 2(RUN x 2),and osteopontin(OPN)).Moreover,SLA-TiCu surface could maintain a sustainable release of Cu2+ions and effectively inhibited the viability of bacteria.This study demonstrated that SLA-TiCu surface possessed multifunctional characteristics of improved osteogenic ability and antibacterial activity,making it promising as a novel implant material for hard tissue repairs such as orthopedics and dental implants.
基金financially supported by the National Key Research and Development Program of China (Nos. 2018YFC1106600 and 2016YFC1100600)the Innovation Fund Project of Institute of Metal Research, Chinese Academy of Sciences (No. 2017-ZD01)+1 种基金the National Natural Science Foundation (Nos. 51631009 and 51811530320)Key Projects for Foreign Cooperation of Bureau of International Cooperation Chinese Academy of Sciences (No. 174321KYSB2018000)
文摘The Ti6Al4V-Cu alloy was reported to show good antibacterial properties, which was promising to reduce the hazard of the bacterial infection problem. For the purpose of preparing Ti6Al4V-Cu alloy with satisfied comprehensive properties, it’s important to study the heat treatment and the appropriate Cu content of the alloy. In this study, high Cu content Ti6Al4V-x Cu(x = 4.5, 6, 7.5 wt%) alloys were prepared, and firstly the annealing heat treatments were optimized in the α+β+Ti2Cu triple phase region to obtain satisfied tensile mechanical properties. Then the effect of Cu content on the tribological property, corrosion resistance, antibacterial activity and cytotoxicity of the Ti6Al4 V-x Cu alloys were systematically studied to obtain the appropriate Cu content. The results showed that the optimal annealing temperatures for Ti6Al4 V-x Cu(x = 4.5, 6, 7.5 wt%) alloys were 720, 740 and 760℃, respectively, which was resulted from the proper volume fractions of α,β and Ti2Cu phases in the microstructure. The additions of 4.5 wt% and 6 wt% Cu into the medical Ti6Al4 V alloy could enhance the wear resistance and corrosion resistance of the alloy, but the addition of 7.5 wt% Cu showed an opposite effect. With the increase of the Cu content, the antibacterial property was enhanced due to the increased volume fraction of Ti2Cu phase in the microstructure, but when the Cu content was increased to 7.5 wt%, cytotoxicity was presented. A medium Cu content of 6 wt%, with annealing temperature of 740℃ make the alloy possesses the best comprehensive properties of tensile properties, wear resistance, corrosion resistance, antibacterial property and biocompatibility, which is promising for future medical applications.
基金supported financially by the National Key Research and Development Program of China (Nos. 2018YFC1106601 and 2016YFC1100600)National Natural Science Foundation (No. 51631009)+2 种基金Youth Innovation Promotion Association, CAS (No. 2014168)Promoting Liaoning Province Talents Program-Top Young Talents (XLYC1807069)the support of CAS-TWAS President Fellowship。
文摘Ti-15 Zr-xCu(3≤x≤7,wt.%) novel antibacterial and antibiofilm alloys with competitive mechanical properties,biological responses and corrosion resistance were designed and fabricated.Annealing heat treatment on Ti-15 Zr-7 Cu(TZC-7 A),after holding for 2 h at slightly above their beta transus temperature(BTT) ensured their tensile strength(UTS),yield strength(YS) and hardness(HRV) were improved by31.2%,20% and 12.3% respectively compared to the control without Cu,Ti-15 Zr(T-15 ZA).Although the3 wt.% Cu alloy displayed the highest elongation(26%),the TZC-7 A alloy also possessed a good ductility.Presence of evenly dispersed Ti2 Cu and Zr2 Cu Cu-rich intermetallic phases formed as interwoven and alternating lamellae within the α+β matrix as a result of Cu addition,as revealed by X-ray diffraction(XRD),scanning electron microscopy(SEM) and transmission electron microscopy(TEM).These greatly contributed to their strengthening and bactericidal properties.Over 98% antibacterial effect against E.coli and S.aureus have been imparted,coupled with excellent biofilm inhibition.Potentiodynamic polarization curves showed that the TZC-7 A alloy possessed higher corrosion resistance than commercially pure titanium,cp-Ti;contact angle test revealed enhanced hydrophilicity;while confocal laser scanning microscopy(CLSM) and cell counting kit(CCK-8) assays also displayed drastically lowered bacterial adhesion rate with comparatively no cytotoxicity.Cell attachment on all alloys was similar but the best spread was obtained on TZC-7 A after 24 h.The developed alloy has good potential as an antibacterial implant material with combination of optimized properties.
基金financially supported by the National Key Research and Development Program of China(Nos.2018YFC1106601 and 2016YFC1100601)the LiaoNing Revitalization Talents Program(No.XLYC1807069)+1 种基金the National Natural Science Foundation of China(Nos.51631009 and 31870954)the Key Projects for Foreign Cooperation of Bureau of International Cooperation Chinese Academy of Sciences(No.174321KYSB2018000)。
文摘In order to reduce implant-related infections and improve early osseointegration,we performed HF+anodic oxidation on the surface of the new antibacterial Ti-Cu alloy to make the titanium-based implants have a micro/submicron structure.On this basis,a series of surface-modified Ti-x Cu alloys with different Cu contents(3,5 and 7 wt%)were fabricated and a comprehensive study was conducted on MC3 T3-E1 cell adhesion,proliferation,apoptosis and its antibacterial activity against Staphylococcus aureus.Results showed that the Ti-x Cu alloys by HF etching+anodized possessed multifunctional characteristics of antibiofilm and antibacterial abilities,excellent biocompatibility and osteogenesis promoting abilities.Increment of Cu content significantly contributed to the antibacterial and osteogenic properties of HF etching+anodized Ti-Cu alloys.Cell proliferation rates of HF etching+anodized Ti-7 Cu alloys were lower than those of Ti-3 Cu and Ti-5 Cu alloys,while the early cell apoptosis rates were higher than Ti-3 Cu and Ti-5 Cu groups.All the above results finally presented that the HF etching+anodized Ti-5 Cu alloy exhibited extremely strong antibacterial properties,good biological compatibility and osteogenic ability,as well as the most excellent ductility and corrosion resistance,providing a great potential application for the future dental implantation.
基金financially supported by the National Key Research and Development Program of China(2018YFC1106601)Liaoning Revitalization Talents Program(XLYC1807069)+1 种基金National Natural Science Foundation(No.51631009,31870954)support of the CSC scholarship。
文摘The adsorption behavior, antibacterial, and corrosion properties of a Ti-3 Cu alloy were studied in a phosphate-buffered saline solution containing 0, 1, 3, and 6 gL^(-1) bovine serum albumin protein at 37℃ and pH = 7.4(±0.2). The protein adsorption behavior was examined via cyclic voltammetry, secondary ions mass spectroscopy(SIMS), and angle-resolved X-ray photoelectron spectroscopy(ARXPS). The corrosion property was analyzed by the open circuit potential(OCP), potentiodynamic polarization(PD),and electrochemical impedance spectroscopy(EIS) examinations. The antibacterial test was conducted according to the GB/T 21510 China Standard. It was observed that the surface charge density(QA DS) was directly proportional to the amount of the adsorbed BSA protein, signifying that the protein adsorption was accompanied by the charge transfer, pointing to chemisorptions phenomena. BSA amino groups and other organic species were observed in the surface analysis examinations. It was shown that the formation of barrier complexes between the TiO_(2) oxide-layer and PBS solution resulted in decreasing the release of Cu-ions, which consequently reduced the antibacterial activity. On the other hand, these barrier complexes improved the corrosion resistance by increasing the charge transfer resistance and double-layer capacitance of the Ti-3 Cu alloy.
基金supported by the Bureau of International Cooperation,Chinese Academy of Sciences[174321KYSB20180006]National Key Research and Development Program of China[2018YFC1106600,2016YFC1100600]+1 种基金Natural Science Foundation of China[51631009,31870954]Liaoning Revitalization Talents Program[XLYC1807069].
文摘This work was focused on study of anti-infection ability and its underlying mechanism of a novel dental implant made of titanium-copper(TiCu)alloy.In general,most studies on antibacterial implants have used a single pathogen to test their anti-infection ability using infectious animal models.However,dental implant-associated infections are polymicrobial diseases.We innovatively combine the classic ligature model in dogs with sucrose-rich diets to induce oral infections via the canine native oral bacteria.The anti-infection ability,biocompatibility and underlying mechanism of TiCu implant were systematically investigated in comparison with pure Ti implant via general inspection,hematology,imageology(micro-CT),microbiology(16S rDNA and metagenome),histology,and Cu ion detections.Compared with Ti implant,TiCu implant demonstrated remarkable anti-infection potentials with excellent biocompatibility.Additionally,the underlying anti-infection mechanism of TiCu implant was considered to involve maintaining the oral microbiota homeostasis.It was found that the carbohydrates in the plaques formed on the surface of TiCu implant were metabolized through the tricarboxylic acid cycle(TCA)cycles,which prevented the formation of an acidic microenvironment and inhibited the accumulation of acidogens and pathogens,thereby maintaining the microflora balance between aerobic and anaerobic bacteria.
基金financially supported by the National Natural Science Foundation of China(Nos.51631009 and 31870954).S.K.Kolawole graciously appreciates CAS-TWAS President Fellowship for the scholarship aid。
文摘The effects of different aging conditions on the microstructure,strength,corrosion resistance,cytotoxicity and antibacterial ability of Ti-15Zr-xCu(3≤x≤7,wt%)(TZC)alloys were systematically investigated.Microstructural evolution and behavior were analyzed by X-ray diffraction(XRD)patterns and scanning electron microscopy with energy-dispersive spectroscopy(SEM-EDS),while potentiodynamic polarization technique was employed to characterize the corrosion response of the alloys after solution-treatment and aging(STA).High-temperature aging at 660℃ for 4 h(660-4)gave the best combination of properties by enabling significant precipitation of the Cu-rich Ti_(2)Cu and Zr_(2)Cu compounds,and mild formation of the Zr_(7)Cu_(10) secondary phase.The high kinetics at this condition was beneficial to the complete precipitation and more homogeneous distribution of the intermetallic particles.These led to the inhibition of dislocation movements and allowed for significantly improved mechanical strengths with added ductility,availability of more Cu ions for the desired oligodynamic activity without evoking cytotoxicity,better corrosion resistance and very high antibacterial ability(over 99.5%),thus improving the overall properties of the TZC alloys for biomedical applications.
