Objective:This study was designed to evaluate the feasibility,efficacy,and safety of percutaneous ureteroscopy laser unroofing as an ambulatory surgery for symptomatic simple renal cysts under multilevel paravertebral...Objective:This study was designed to evaluate the feasibility,efficacy,and safety of percutaneous ureteroscopy laser unroofing as an ambulatory surgery for symptomatic simple renal cysts under multilevel paravertebral nerve block anesthesia.Methods:From December 2015 to September 2017,33 simple renal cyst patients who had surgical indications were enrolled.Under ultrasound guidance,the T10/T11,T11/T12,and T12/L1 paravertebral spaces were identified,and 7-10 mL 0.5%ropivacaine was injected at each segment.Then a puncture needle was placed inside the cyst cavity under ultrasonic monitoring.A guidewire was introduced followed by sequential dilation up to 28/30 Fr.The extra parenchymal portion of the cyst wall was dissociated and incised using a thulium laser,and a pathological examination was performed.Results:Sensory loss to pinprick from T8 to L1 and sensory loss to ice from T6 to L2 were observed in all patients.None of the patients complained of pain during surgery.No serious complications occurred perioperatively.After the surgery,all patients recovered their lower limb muscle strength quickly,got out of bed,resumed oral feeding,and left the hospital within 24 h of admission.The pathologic diagnosis of all cyst walls was a simple renal cyst.The mean follow-up was 35.8 months.At the end of follow-up,the cyst units were reduced in size by more than 50%compared to the preoperative size,and no patient experienced a recurrence.Conclusion:Multi-level paravertebral nerve block for percutaneous ureteroscopy laser unroofing as an ambulatory surgery mode is feasible,safe,and effective for the treatment of simple renal cysts in selected patients.展开更多
Although some genes that cause Kallmann syndrome (KS) have been identified by traditional linkage analysis and candidate gene techniques, the syndrome's molecular etiology in the majority of patients remains poorly...Although some genes that cause Kallmann syndrome (KS) have been identified by traditional linkage analysis and candidate gene techniques, the syndrome's molecular etiology in the majority of patients remains poorly understood. In this paper, we present the clinical assessments of a consanguineous Hart Chinese family with three KS descendants. To understand the molecular etiology of KS from a genome-wide perspective, we investigated the genome-wide profile of structural variation in this family using the Affymetrix Genome-Wide Human SNP Array 6.0 platform. The results revealed that the three affected individuals had common copy number variants (microdeletions) on chromosomes lp21.1, 2q32.2, 8q21.13, 14q21.2 and Xp22.31. Moreover, the copy number variants on Xp22.31 were located in the intron of KAL 1, which causes X-linked KS. Two PCR assays were performed on these regions to validate the results obtained using the chips. In addition, genomic microdeletions in this region were verified in one of 29 Han Chinese sporadic KS cases and one of four other family cases, but not in 26 Han Chinese sporadic normosmic idiopathic hypogonadotropic hypogonadism cases and 100 unrelated Han Chinese normal controls. Our results provide a novel insight into the relative contributions of certain copy number variants to KS's molecular etiology and generate a list of interesting candidate regions for further studies.展开更多
Natural fish scales demonstrate outstanding mechanical efficiency owing to their elaborate architectures and thereby may serve as ideal prototypes for the architectural design of man-made materials.Here bioinspired ma...Natural fish scales demonstrate outstanding mechanical efficiency owing to their elaborate architectures and thereby may serve as ideal prototypes for the architectural design of man-made materials.Here bioinspired magnesium composites with fish-scale-like orthogonal plywood and double-Bouligand architectures were developed by pressureless infiltration of a magnesium melt into the woven contextures of continuous titanium fibers.The composites exhibit enhanced strength and work-hardening ability compared to those estimated from a simple mixture of their constituents at ambient to elevated temperatures.In particular,the double-Bouligand architecture can effectively deflect cracking paths,alleviate strain localization,and adaptively reorient titanium fibers within the magnesium matrix during the deformation of the composite,representing a successful implementation of the property-optimizing mechanisms in fish scales.The strength of the composites,specifically the effect of their bioinspired architectures,was interpreted based on the adaptation of classical laminate theory.This study may offer a feasible approach for developing new bioinspired metal-matrix composites with improved performance and provide theoretical guidance for their architectural designs.展开更多
Objective:To investigate oncological outcomes in patients with bladder cancer who underwent minimally invasive radical cystectomy(MIRC)or open radical cystectomy(ORC).Methods:We identified patients with bladder cancer...Objective:To investigate oncological outcomes in patients with bladder cancer who underwent minimally invasive radical cystectomy(MIRC)or open radical cystectomy(ORC).Methods:We identified patients with bladder cancer who underwent radical cystectomy(RC)in 13 centers of the Chinese Bladder Cancer Consortium(CBCC).Perioperative outcomes were compared between MIRC and ORC.The influence of surgical approaches on overall survival(OS)and cancer-specific survival(CSS)in the entire study group and subgroups classified according to pathologic stage or lymph node(LN)status was assessed with the log-rank test.Multivariable Cox proportional hazard models were used to evaluate the association among OS,CSS and risk factors of interest.Results:Of 2098 patients who underwent RC,1243 patients underwent MIRC(1087 laparoscopic RC and 156 robotic-assisted RC,respectively),while 855 patients underwent ORC.No significant differences were noted in positive surgical margin rate and 90-day postoperative mortality rate.MIRC was associated with less estimated blood loss,more LN yield,higher rate of neobladder diversion,longer operative time,and longer length of hospital stay.There was no significant difference in OS and CSS according to surgical approaches(pZ0.653,and 0.816,respectively).Subgroup analysis revealed that OS and CSS were not significantly different regardless of the status of extravesical involvement or LN involvement.Multivariable Cox regression analyses showed that the surgical approach was not a significant predictor of OS and CSS.Conclusions:Our study showed that MIRC was comparable to conventional ORC in terms of OS and CSS.展开更多
Lithium sulfur batteries are one of the most promising alternative electrochemical systems,but their practical applications are largely hindered by the serious shuttling problems and sluggish redox kinetics.Here,the c...Lithium sulfur batteries are one of the most promising alternative electrochemical systems,but their practical applications are largely hindered by the serious shuttling problems and sluggish redox kinetics.Here,the conductive and polar niobium nitride(NbN)is in-situ introduced onto graphene with ultrasmall size and high dispersion,and their composite is used to construct an efficient lithium polysulfide blocking layer.The graphene helps to construct highly conductive pathways,and niobium nitride serves as the sulfiphilic sites to chemically adsorb the migrating lithium polysulfides and catalyze their redox conversion.Hence,the cells with the Nb N/G interlayers exhibit a long cycle life with a lower capacity decay of 0.096%/cycle at 1 C for 300 cycles and high rate capability of 937 m Ah g^-1 at 2 C.Further coupling with a sulfur/carbon nanofiber electrode,the cell with an ultra-high sulfur loading of 10.8 mg cm^-2 delivers an areal capacity of 12.5 m Ah cm^-2 at 0.1 C.展开更多
Objective:Real-word data on long-acting luteinizing hormone-releasing hormone(LHRH)agonists in Chinese patients with prostate cancer are limited.This study aimed to determine the real-world effectiveness and safety of...Objective:Real-word data on long-acting luteinizing hormone-releasing hormone(LHRH)agonists in Chinese patients with prostate cancer are limited.This study aimed to determine the real-world effectiveness and safety of the LHRH agonist,goserelin,particularly the long-acting 10.8-mg depot formulation,and the follow-up patterns among Chinese prostate cancer patients.Methods:This was a multicenter,prospective,observational study in hormone treatment-na?ve patients with localized or locally advanced prostate cancer who were prescribed goserelin 10.8-mg depot every 12 weeks or 3.6-mg depot every 4 weeks with or without an anti-androgen.The patients had follow-up evaluations for 26 weeks.The primary outcome was the effectiveness of goserelin in reducing serum testosterone and prostate-specific antigen(PSA)levels.The secondary outcomes included testosterone and PSA levels,attainment of chemical castration(serum testosterone<50 ng/d L),and goserelin safety.The exploratory outcome was the monitoring pattern for serum testosterone and PSA.All analyses were descriptive.Results:Between September 2017 and December 2019,a total of 294 eligible patients received≥1 dose of goserelin;287 patients(97.6%)were treated with goserelin 10.8-mg depot.At week 24±2,the changes from baseline[standard deviation(95%confidence interval)]in serum testosterone(n=99)and PSA(n=131)were-401.0 ng/d L[308.4 ng/d L(-462.5,-339.5 ng/d L)]and-35.4 ng/m L[104.4 ng/m L(-53.5,-17.4 ng/m L)],respectively.Of 112 evaluable patients,100(90.2%)achieved a serum testosterone level<50 ng/d L.Treatment-emergent adverse events(TEAEs)and severe TEAEs occurred in 37.1%and 10.2%of patients,respectively.The mean testing frequency(standard deviation)was 1.6(1.5)for testosterone and 2.2(1.6)for PSA.Conclusions:Goserelin 10.8-mg depot effectively achieved and maintained castration and was well-tolerated in Chinese patients with localized and locally advanced prostate cancer.展开更多
Objective:To evaluate the efficiency,safety and clinical outcomes of Retziussparing robot-assisted radical prostatectomy(RS-RARP)in comparison with the standard RARP.Methods:A systematic search from Web of Science,Pub...Objective:To evaluate the efficiency,safety and clinical outcomes of Retziussparing robot-assisted radical prostatectomy(RS-RARP)in comparison with the standard RARP.Methods:A systematic search from Web of Science,PubMed,EMBase,Cochrane Library and Google Scholar was performed using the terms“Retzius-sparing”,“Bocciardi approach”and“robot-assisted radical prostatectomy”.Video articles and abstract papers for academic conferences were excluded.Meta-analysis of interested outcomes such as positive surgical margins(PSMs)and continence recovery was undertaken.A comprehensive literature review of all studies regarding Retzius-sparing(RS)approach was conducted and summarized.Results:From 2010 to 2017,11 original articles about RS-RARP approach were retrieved.Of that,only four studies comparing the RS-RARP approach to the conventional RARP were comparable for meta-analysis.Faster overall continence recovery within 1 month after the surgery was noted in the RS group(61%vs.43%;pZ0.004).PSMs of pT2 and pT3 stages were not significantly different between the groups(10.0%vs.7.4%;p Z 0.39 and 13.1%vs.9.5%,p Z 0.56,respectively).Of all the studies,only one reported sexual recovery outcomes after RS treatment in which 40%of the participants achieved sexual intercourse within the first month.Conclusion:Though more technically demanding than the conventional RARP,the RS technique is a safe and feasible approach.This meta-analysis and literature review indicates that RS technique,as opposed to the conventional approach,is associated with a faster continence recovery while PSMs were comparable between the two groups.The limitations of observational studies and the small data in our meta-analysis may prevent an ultimate conclusion.Future well-designed RCTs are needed to validate and confirm our findings.展开更多
Objective:To present our experience and technique with robot-assisted uretero-neocystos tomy(RAUN)procedure in adults.Methods:Between February 2015 and August 2018,a total of 30(34 ureters)patients who un-derwent RAUN...Objective:To present our experience and technique with robot-assisted uretero-neocystos tomy(RAUN)procedure in adults.Methods:Between February 2015 and August 2018,a total of 30(34 ureters)patients who un-derwent RAUN surgery under a single surgeon were retrospectively reviewed.Perioperative data such as age,sex,body mass index(BMI),American society of anesthes iologists score,esti-mated blood loss,surgical technique,operative time,complications,length of hospital stay,and stent removal time were recorded.During the follow-up,patients underwent renal func-tion test,urinalysis,and renal ultrasound examination for evaluation.Success was defined as symptomatic and radiologic relieve.Lastly,a literature search was conducted to review all published articles regarding RAUN surgery in adults.Results:The patients'mean age,BMI,EBL,operative time,and follow-up period were 45.4 years,23.1 kg/m^2,65.6 mL,182.9 min,and 21.3 months,respectively.The two most common indications for the surgery were benign ureteral strictures and ureteric injuries secondaryto a previous radical hysterectomy.Of the 34 cases,26(76.5%)and 8(23.5%)patients received pri-mary RAUN and RAUN with psoas hitch technique,respectively.Refluxing RAUN method was performed in all cases.No intraoperative complications were found.Two patients had a radio-logic and symptomatic recurrence;one was managed with a repeat surgery while the other received ureteral dilatation treatment.Conclusion:Both our study and the published literature showed that RAUN is a safe,less inva-sive,and effective surgical technique that can easily replicate the open ureteroneocystostomy for managing lower ureteral diseases.展开更多
Electrical contact materials are generally Ag-or Cu-based composites and play a critical role in ensuring the reliability and efficiency of electrical equipments and electronic instruments.The MAX(M is an early transi...Electrical contact materials are generally Ag-or Cu-based composites and play a critical role in ensuring the reliability and efficiency of electrical equipments and electronic instruments.The MAX(M is an early transition metal,A is an element from III or IV main groups,and X is carbon or/and nitrogen)phase ceramics display a unique combination of properties and may serve as an ideal reinforcement phase for electrical contact materials.The biological materials evolved in nature generally exhibit three-dimensional(3D)interpenetrating-phase architectures,which may offer useful inspiration for the architectural design of electrical contact materials.Here,a series of bi-continuous Ag-Ti_(3)SiC_(2) MAX phase composites with high ceramic contents exceeding 50 vol.%and having micron-and ultrafine-scaled 3D interpenetrating-phase architectures,wherein both constituents were continuous and mutually interspersed,were exploited by pressureless infiltration of Ag melt into partially sintered Ti_(3)SiC_(2) scaffolds.The mechanical and electrical properties as well as the friction and wear performance of the composites were investigated and revealed to be closely dependent on the ceramic contents and characteristic structural dimensions.The composites exhibited a good combination of properties with high hardness over 2.3 GPa,high flexural strength exceeding 530 MPa,decent fracture toughness over 10 MPa·m^(1/2),and good wear resistance with low wear rate at an order of 10^(-5)mm^(3)/(N·m),which were much superior compared to the counterparts made by powder metallurgy methods.In particular,the hardness,electrical conductivity,strength,and fracture toughness of the composites demonstrated a simultaneous improvement as the structure was refined from micron-to ultrafine-scales at equivalent ceramic contents.The good combination of properties along with the facile processing route makes the Ag-Ti_(3)SiC_(2)3D interpenetrating-phase composites appealing for electrical contact applications.展开更多
DNA circuits are powerful tools in various applications such as logical computation,molecular diagnosis and synthetic biology.Leakage is a major problem in constructing complex DNA circuits.It directly affects the out...DNA circuits are powerful tools in various applications such as logical computation,molecular diagnosis and synthetic biology.Leakage is a major problem in constructing complex DNA circuits.It directly affects the output signal and harms the circuit’s performance significantly.In the traditional DNA circuits,the gate complex is a duplex structure.There are insufficient energy barriers to prevent spontaneous detachment of strands,resulting in a leak prone.Herein,we have developed triplex-structure based DNA circuit with ultra-low leakage and high signal-to-noise ratio(SNR).The triplex structure improves the stability in the absence of input.At the same time,the driving force of the strand displacement cascades reduces the influence of the triplex structure on the desired reaction.The SNR of the DNA circuit was increased to 695,while the desired reaction rate remained 90%of the conventional translator circuit.The triplex-structure mediated leakage prevention strategy was further tested at different temperatures and in DNA translator and seesaw circuits.We also constructed modular basic logic gates with a high efficiency and low leakage.On this basis,we further constructed triplex-structure based tertiary DNA logic circuits,and the SNR reached 295,which,to the best of our knowledge,was among the highest of the field.We believe that our scheme provides a novel,valid,and general tool for reducing leakages,and we anticipate that it will be widely adopted in DNA nanotechnology.展开更多
The strength and thermal conductivity of compacted graphite iron(CGI)are crucial performance indicators in its engineering application.The presence of graphite in CGI significantly influences the two properties.In the...The strength and thermal conductivity of compacted graphite iron(CGI)are crucial performance indicators in its engineering application.The presence of graphite in CGI significantly influences the two properties.In the previous studies,graphite in CGI was often described using two-dimensional(2D)morphology.In this study,the three-dimensional(3D)size,shape,and distribution of graphite in CGI were analyzed using X-ray tomography.Based on this,a new method is introduced to calculate the 3D vermicularity and compare it with the 2D vermicularity in terms of tensile properties and thermal conductivity.The results demonstrate that vermicular graphite exhibits greater connectivity in 3D observation compared to 2D observation.Therefore,the calculation method of 3D vermicularity is determined by considering the surface area and volume of the connected graphite.Then a linear relationship between 3 and 2D vermicularity has been observed.By comparing the correlation coefficient,it has been found that the 3D vermicularity offers a more accurate method to establish the relationship among graphite morphology,thermal conductivity and tensile property of CGI.展开更多
Transpiration cooling technique is a reusable and high-efficiency thermal protection system(TPS),which is potential to improve the reusability and security of re-entry space vehicle.Relatively low density,high permeab...Transpiration cooling technique is a reusable and high-efficiency thermal protection system(TPS),which is potential to improve the reusability and security of re-entry space vehicle.Relatively low density,high permeability and high porosity are general requirements for porous media of transpiration cooling systems.In this work,a new porous high entropy metal hexaboride(Y0.2Yb0.2Sm0.2Nd0.2Eu0.2)B6 is designed and prepared by the in-situ reaction/partial sintering method.Two reaction routes are designed to synthesize(Y0.2Yb0.2Sm0.2Nd0.2Eu0.2)B6,including boron thermal reduction and borocarbon thermal reduction.The as-prepared porous HE(Y0.2Yb0.2Sm0.2Nd0.2Eu0.2)B6 ceramics possess homogeneous microstructure and exhibit low density,high porosity,high compressive strength and high permeability.The combination of these properties makes porous HE(Y0.2Yb0.2Sm0.2Nd0.2Eu0.2)B6 promising as a candidate porous media for various transpiration cooling applications.展开更多
The structures of tungsten and tungsten carbide scaffolds play a key role in determining the properties of their infiltrated composites for multifunctional applications.However,it is challenging to construct and contr...The structures of tungsten and tungsten carbide scaffolds play a key role in determining the properties of their infiltrated composites for multifunctional applications.However,it is challenging to construct and control the architectures by means of self-assembly in W/WC systems because of their large densities.Here we present the development of unidirectionally porous architectures,with high porosities exceeding 65 vol.%,for W and WC scaffolds which in many respects reproduce the design motif of natural wood using a direct ice-templating technique.This was achieved by adjusting the viscosities of suspensions to retard sedimentation during freezing.The processing,structural characteristics and mechanical properties of the resulting scaffolds were investigated with the correlations between them explored.Quantitative relationships were established to describe their strengths based on the mechanics of cellular solids by taking into account both inter-and intra-lamellar pores.The fracture mechanisms were also identified,especially in light of the porosity.This study extends the effectiveness of the ice-templating technique for systems with large densities or particle sizes.It further provides preforms for developing new natureinspired multifunctional materials,as represented by W/WC-Cu composites.展开更多
Post-weld single aging treatment(solution treatment at 510 ℃ for 1 h, water quenching,and aging at 155 ℃ for 16 h) and post-weld double aging treatment(solution treatment at 510 ℃ for 1 h, water quenching, aging...Post-weld single aging treatment(solution treatment at 510 ℃ for 1 h, water quenching,and aging at 155 ℃ for 16 h) and post-weld double aging treatment(solution treatment at 510 ℃ for 1 h, water quenching, aging at 155 ℃ for 16 h, and aging at 130 ℃ for 12 h) are carried out on Al-Cu-Li alloy joints by electron beam welding(EBW) respectively. The effects of aging treatments on microstructures and mechanical properties of welded joints are investigated. Results show that the mechanical properties of welded joints are obviously improved after both aging treatments. The strength coefficient of joints is increased from 0.64 in an as-welded condition(AW) to 0.90 after post-weld double aging treatment. Microstructure analysis shows that the precipitates of the fusion zone within grains and grain boundaries are less in the AW condition. After post-weld heat treatment(PWHT), a lot of fine needle-like phases T_1(Al_2 Cu Li) precipitate in grain boundaries of the fusion zone, and more horseshoe-shaped β' (Al_3 Zr) particles precipitate within grains. In addition,grains of the fusion zone are refined after post-weld double aging treatment, which leads to an effect of grain refinement strengthening. Consequently, the mechanical properties of welded joints are greatly improved.展开更多
The evolution of micro-pores in a single crystal nickel-based superalloy during creep at 980 ℃/220 MPa was investigated by X-ray computed tomography. Time-dependent ex-situ 3D information including the number, volume...The evolution of micro-pores in a single crystal nickel-based superalloy during creep at 980 ℃/220 MPa was investigated by X-ray computed tomography. Time-dependent ex-situ 3D information including the number, volume fraction, distribution and morphology of micro-pores was analyzed. The results reveal that the signifi cant formation and growth of micro-pores occur at the end of secondary/beginning of tertiary creep stage. The irregular large pores as well as high density pores located at strain concentration region are the major detrimental factors facilitating the creep damage. Creep failure is resulted from the connection of surface cracks induced by oxidation, and the internal cracks generated from growth and merging of micro-pores.展开更多
Electron beam melting (EBM) has been used to manufacture β-type Ti-24Nb-4Zr-8Sn porous compo- nents with 70% porosity, EBM-produced components have favorable structural features (i.e. smooth strut surfaces, fewer ...Electron beam melting (EBM) has been used to manufacture β-type Ti-24Nb-4Zr-8Sn porous compo- nents with 70% porosity, EBM-produced components have favorable structural features (i.e. smooth strut surfaces, fewer defects) and an (α + β)-type microstructure, similar to that subjected to aging treat- ment. EBM-produced components exhibit more than twice the strength-to-modulus ratio of porous Ti- 6A1-4V components having the same porosity. The processing-microstructure-property relationship and deformation behavior of EBM-produced components are discussed in detail. Such porous titanium com- ponents composed of non-toxic elements and having high strength-to-modulus ratio are highly attractive for biomedical applications.展开更多
Mg(and Mg alloys)and Ti(and Ti alloys)are two important classes of metallic implant materials which are respectively completely degradable and non-degradable after implantation.Making composites composed of them offer...Mg(and Mg alloys)and Ti(and Ti alloys)are two important classes of metallic implant materials which are respectively completely degradable and non-degradable after implantation.Making composites composed of them offers the promise for combining their property advantages for bone repair.Here,we present a Mg-Ti composite fabricated by pressureless infiltration of pure Mg melt into 3D printed Ti scaffold,and demonstrate a potential of the composite for use as new partially degradable and bioactive implant materials.The composite has such architecture that the Mg and Ti phases are topologically bicontinuous and mutually interspersed in 3D space,and exhibits several advantages over its constituents,such as higher strengths than as-cast pure Mg and Ti scaffold along with lower Young’s modulus than dense Ti.Additionally,the degradation of Mg phase may induce the formation and ingrowth of new bone tissues into the Ti scaffold to form mechanical interlocking between them;in this process,the Ti scaffold provides constant support and Young’s modulus adaptively decreases toward that of bone.Despite the accelerated corrosion than pure Mg,the composite remains non-cytotoxic and does not cause obvious adverse reactions after implantation as revealed by in vitro and in vivo experiments.This study may offer a new possibility for combining mechanical durability and bioactivity in implant materials,and allow for customized and targeted design of the implant.展开更多
Detailed three-dimensional(3 D)microtomography characterizations of inclusions in electrode matrix,mushy zone(MZ)and liquid melt film(LMF)were performed to elucidate the motion and removal behavior of inclusions in el...Detailed three-dimensional(3 D)microtomography characterizations of inclusions in electrode matrix,mushy zone(MZ)and liquid melt film(LMF)were performed to elucidate the motion and removal behavior of inclusions in electrode tip during magnetically controlled electroslag remelting(MC-ESR)process.A transient 2 D numerical model was also built to verify the experimental results and proposed mechanisms.The number and size of inclusions exhibited an obvious increasing trend from edge to mid region in LMF,while remained almost the same in electrode matrix and MZ.The inclusions in LMF migrated from edge to mid region of LMF,accompanied with removal process.In addition,the kinetic conditions for inclusion migrating to LMF/slag interface(LSI)were enhanced during MC-ESR process,thereby improving the inclusion removal efficiency in LMF.This work highlights the 3 D characterization and motion/removal mechanisms of inclusions in electrode tip,as well as sheds new light on preparing high purity materials.展开更多
The replacement of synthetic foam materials using natural biological ones is of great significance for saving energy/resources and reducing environmental pollutions.Here we characterized the microstructure and mechani...The replacement of synthetic foam materials using natural biological ones is of great significance for saving energy/resources and reducing environmental pollutions.Here we characterized the microstructure and mechanical properties of natural cornstalk pith,which has a large annual output yet lacks an effective exploitation,and evaluated its feasibility for applications as a substitute for synthetic foam materials.The cornstalk pith was revealed to be a cellular material composed of closed cells elongated along the growth direction of com plant and reinforced by well-aligned vascular bundles penetrating the foam matrix.The compressive behavior is featured by a stable stress plateau which is favorable for energy absorption with its mechanical properties largely dependent on the hydration state and loading configuration.In particular,the initial dimension and mechanical properties of cornstalk pith can be effectively recovered after deformation simply by hydration treatment owing to swelling effect caused by the turgor pressure from osmosis.The cornstalk pith demonstrates an outstanding combination of low density and high energy absorption efficiency among various foam materials,specifically with its plateau stress and energy absorption comparable or even superior to those of some typical synthetic foam materials.These along with the huge resources and good biodegradability make it a promising natural energy absorbing cellular material for replacing synthetic counterparts.展开更多
文摘Objective:This study was designed to evaluate the feasibility,efficacy,and safety of percutaneous ureteroscopy laser unroofing as an ambulatory surgery for symptomatic simple renal cysts under multilevel paravertebral nerve block anesthesia.Methods:From December 2015 to September 2017,33 simple renal cyst patients who had surgical indications were enrolled.Under ultrasound guidance,the T10/T11,T11/T12,and T12/L1 paravertebral spaces were identified,and 7-10 mL 0.5%ropivacaine was injected at each segment.Then a puncture needle was placed inside the cyst cavity under ultrasonic monitoring.A guidewire was introduced followed by sequential dilation up to 28/30 Fr.The extra parenchymal portion of the cyst wall was dissociated and incised using a thulium laser,and a pathological examination was performed.Results:Sensory loss to pinprick from T8 to L1 and sensory loss to ice from T6 to L2 were observed in all patients.None of the patients complained of pain during surgery.No serious complications occurred perioperatively.After the surgery,all patients recovered their lower limb muscle strength quickly,got out of bed,resumed oral feeding,and left the hospital within 24 h of admission.The pathologic diagnosis of all cyst walls was a simple renal cyst.The mean follow-up was 35.8 months.At the end of follow-up,the cyst units were reduced in size by more than 50%compared to the preoperative size,and no patient experienced a recurrence.Conclusion:Multi-level paravertebral nerve block for percutaneous ureteroscopy laser unroofing as an ambulatory surgery mode is feasible,safe,and effective for the treatment of simple renal cysts in selected patients.
文摘Although some genes that cause Kallmann syndrome (KS) have been identified by traditional linkage analysis and candidate gene techniques, the syndrome's molecular etiology in the majority of patients remains poorly understood. In this paper, we present the clinical assessments of a consanguineous Hart Chinese family with three KS descendants. To understand the molecular etiology of KS from a genome-wide perspective, we investigated the genome-wide profile of structural variation in this family using the Affymetrix Genome-Wide Human SNP Array 6.0 platform. The results revealed that the three affected individuals had common copy number variants (microdeletions) on chromosomes lp21.1, 2q32.2, 8q21.13, 14q21.2 and Xp22.31. Moreover, the copy number variants on Xp22.31 were located in the intron of KAL 1, which causes X-linked KS. Two PCR assays were performed on these regions to validate the results obtained using the chips. In addition, genomic microdeletions in this region were verified in one of 29 Han Chinese sporadic KS cases and one of four other family cases, but not in 26 Han Chinese sporadic normosmic idiopathic hypogonadotropic hypogonadism cases and 100 unrelated Han Chinese normal controls. Our results provide a novel insight into the relative contributions of certain copy number variants to KS's molecular etiology and generate a list of interesting candidate regions for further studies.
基金the financial support by the National Key R&D Program of China under grant number 2020YFA0710404the National Natural Science Foundation of China under grant number 51871216+6 种基金the KC Wong Education Foundation(GJTD-2020-09)the Liao Ning Revitalization Talents Programthe State Key Laboratory for Modification of Chemical Fibers and Polymer Materials at Donghua Universitythe Opening Project of Jiangsu Province Key Laboratory of High-End Structural Materials under grant number hsm1801the Opening Project of National Key Laboratory of Shock Wave and Detonation Physics under grant number 6142A03203002the Youth Innovation Promotion Association CASsupported by the Multi-University Research Initiative under grant number AFOSR-FA9550-151-0009 from the Air Force Office of Scientific Research
文摘Natural fish scales demonstrate outstanding mechanical efficiency owing to their elaborate architectures and thereby may serve as ideal prototypes for the architectural design of man-made materials.Here bioinspired magnesium composites with fish-scale-like orthogonal plywood and double-Bouligand architectures were developed by pressureless infiltration of a magnesium melt into the woven contextures of continuous titanium fibers.The composites exhibit enhanced strength and work-hardening ability compared to those estimated from a simple mixture of their constituents at ambient to elevated temperatures.In particular,the double-Bouligand architecture can effectively deflect cracking paths,alleviate strain localization,and adaptively reorient titanium fibers within the magnesium matrix during the deformation of the composite,representing a successful implementation of the property-optimizing mechanisms in fish scales.The strength of the composites,specifically the effect of their bioinspired architectures,was interpreted based on the adaptation of classical laminate theory.This study may offer a feasible approach for developing new bioinspired metal-matrix composites with improved performance and provide theoretical guidance for their architectural designs.
基金supported by the National Natural Science Foundation of China(Grant No.81825016,81772719,81772728,81572514)the Key Areas Research and Development Program of Guangdong(Grant No.2018B010109006)Medical Scientific Research Foundation of Guangdong Province(Grant No.A2018388).
文摘Objective:To investigate oncological outcomes in patients with bladder cancer who underwent minimally invasive radical cystectomy(MIRC)or open radical cystectomy(ORC).Methods:We identified patients with bladder cancer who underwent radical cystectomy(RC)in 13 centers of the Chinese Bladder Cancer Consortium(CBCC).Perioperative outcomes were compared between MIRC and ORC.The influence of surgical approaches on overall survival(OS)and cancer-specific survival(CSS)in the entire study group and subgroups classified according to pathologic stage or lymph node(LN)status was assessed with the log-rank test.Multivariable Cox proportional hazard models were used to evaluate the association among OS,CSS and risk factors of interest.Results:Of 2098 patients who underwent RC,1243 patients underwent MIRC(1087 laparoscopic RC and 156 robotic-assisted RC,respectively),while 855 patients underwent ORC.No significant differences were noted in positive surgical margin rate and 90-day postoperative mortality rate.MIRC was associated with less estimated blood loss,more LN yield,higher rate of neobladder diversion,longer operative time,and longer length of hospital stay.There was no significant difference in OS and CSS according to surgical approaches(pZ0.653,and 0.816,respectively).Subgroup analysis revealed that OS and CSS were not significantly different regardless of the status of extravesical involvement or LN involvement.Multivariable Cox regression analyses showed that the surgical approach was not a significant predictor of OS and CSS.Conclusions:Our study showed that MIRC was comparable to conventional ORC in terms of OS and CSS.
基金financial support from the National Key R&D Program of China(2016YFB0100100 and 2016YFA0200100)the National Natural Science Foundation of China(Nos.51972313,51525206 and 51521091)+1 种基金the Strategic Priority Research Program of Chinese Academy of Science(XDA22010602)China Petrochemical Cooperation(No.218025)。
文摘Lithium sulfur batteries are one of the most promising alternative electrochemical systems,but their practical applications are largely hindered by the serious shuttling problems and sluggish redox kinetics.Here,the conductive and polar niobium nitride(NbN)is in-situ introduced onto graphene with ultrasmall size and high dispersion,and their composite is used to construct an efficient lithium polysulfide blocking layer.The graphene helps to construct highly conductive pathways,and niobium nitride serves as the sulfiphilic sites to chemically adsorb the migrating lithium polysulfides and catalyze their redox conversion.Hence,the cells with the Nb N/G interlayers exhibit a long cycle life with a lower capacity decay of 0.096%/cycle at 1 C for 300 cycles and high rate capability of 937 m Ah g^-1 at 2 C.Further coupling with a sulfur/carbon nanofiber electrode,the cell with an ultra-high sulfur loading of 10.8 mg cm^-2 delivers an areal capacity of 12.5 m Ah cm^-2 at 0.1 C.
文摘Objective:Real-word data on long-acting luteinizing hormone-releasing hormone(LHRH)agonists in Chinese patients with prostate cancer are limited.This study aimed to determine the real-world effectiveness and safety of the LHRH agonist,goserelin,particularly the long-acting 10.8-mg depot formulation,and the follow-up patterns among Chinese prostate cancer patients.Methods:This was a multicenter,prospective,observational study in hormone treatment-na?ve patients with localized or locally advanced prostate cancer who were prescribed goserelin 10.8-mg depot every 12 weeks or 3.6-mg depot every 4 weeks with or without an anti-androgen.The patients had follow-up evaluations for 26 weeks.The primary outcome was the effectiveness of goserelin in reducing serum testosterone and prostate-specific antigen(PSA)levels.The secondary outcomes included testosterone and PSA levels,attainment of chemical castration(serum testosterone<50 ng/d L),and goserelin safety.The exploratory outcome was the monitoring pattern for serum testosterone and PSA.All analyses were descriptive.Results:Between September 2017 and December 2019,a total of 294 eligible patients received≥1 dose of goserelin;287 patients(97.6%)were treated with goserelin 10.8-mg depot.At week 24±2,the changes from baseline[standard deviation(95%confidence interval)]in serum testosterone(n=99)and PSA(n=131)were-401.0 ng/d L[308.4 ng/d L(-462.5,-339.5 ng/d L)]and-35.4 ng/m L[104.4 ng/m L(-53.5,-17.4 ng/m L)],respectively.Of 112 evaluable patients,100(90.2%)achieved a serum testosterone level<50 ng/d L.Treatment-emergent adverse events(TEAEs)and severe TEAEs occurred in 37.1%and 10.2%of patients,respectively.The mean testing frequency(standard deviation)was 1.6(1.5)for testosterone and 2.2(1.6)for PSA.Conclusions:Goserelin 10.8-mg depot effectively achieved and maintained castration and was well-tolerated in Chinese patients with localized and locally advanced prostate cancer.
文摘Objective:To evaluate the efficiency,safety and clinical outcomes of Retziussparing robot-assisted radical prostatectomy(RS-RARP)in comparison with the standard RARP.Methods:A systematic search from Web of Science,PubMed,EMBase,Cochrane Library and Google Scholar was performed using the terms“Retzius-sparing”,“Bocciardi approach”and“robot-assisted radical prostatectomy”.Video articles and abstract papers for academic conferences were excluded.Meta-analysis of interested outcomes such as positive surgical margins(PSMs)and continence recovery was undertaken.A comprehensive literature review of all studies regarding Retzius-sparing(RS)approach was conducted and summarized.Results:From 2010 to 2017,11 original articles about RS-RARP approach were retrieved.Of that,only four studies comparing the RS-RARP approach to the conventional RARP were comparable for meta-analysis.Faster overall continence recovery within 1 month after the surgery was noted in the RS group(61%vs.43%;pZ0.004).PSMs of pT2 and pT3 stages were not significantly different between the groups(10.0%vs.7.4%;p Z 0.39 and 13.1%vs.9.5%,p Z 0.56,respectively).Of all the studies,only one reported sexual recovery outcomes after RS treatment in which 40%of the participants achieved sexual intercourse within the first month.Conclusion:Though more technically demanding than the conventional RARP,the RS technique is a safe and feasible approach.This meta-analysis and literature review indicates that RS technique,as opposed to the conventional approach,is associated with a faster continence recovery while PSMs were comparable between the two groups.The limitations of observational studies and the small data in our meta-analysis may prevent an ultimate conclusion.Future well-designed RCTs are needed to validate and confirm our findings.
文摘Objective:To present our experience and technique with robot-assisted uretero-neocystos tomy(RAUN)procedure in adults.Methods:Between February 2015 and August 2018,a total of 30(34 ureters)patients who un-derwent RAUN surgery under a single surgeon were retrospectively reviewed.Perioperative data such as age,sex,body mass index(BMI),American society of anesthes iologists score,esti-mated blood loss,surgical technique,operative time,complications,length of hospital stay,and stent removal time were recorded.During the follow-up,patients underwent renal func-tion test,urinalysis,and renal ultrasound examination for evaluation.Success was defined as symptomatic and radiologic relieve.Lastly,a literature search was conducted to review all published articles regarding RAUN surgery in adults.Results:The patients'mean age,BMI,EBL,operative time,and follow-up period were 45.4 years,23.1 kg/m^2,65.6 mL,182.9 min,and 21.3 months,respectively.The two most common indications for the surgery were benign ureteral strictures and ureteric injuries secondaryto a previous radical hysterectomy.Of the 34 cases,26(76.5%)and 8(23.5%)patients received pri-mary RAUN and RAUN with psoas hitch technique,respectively.Refluxing RAUN method was performed in all cases.No intraoperative complications were found.Two patients had a radio-logic and symptomatic recurrence;one was managed with a repeat surgery while the other received ureteral dilatation treatment.Conclusion:Both our study and the published literature showed that RAUN is a safe,less inva-sive,and effective surgical technique that can easily replicate the open ureteroneocystostomy for managing lower ureteral diseases.
基金supports from the National Key R&D Program of China(No.2020YFA0710404)the National Natural Science Foundation of China(No.52173269),the KC Wong Education Foundation(No.GJTD-2020-09)the Liaoning Revitalization Talents Program,and the Youth Innovation Promotion Association CAS(No.2019191).
文摘Electrical contact materials are generally Ag-or Cu-based composites and play a critical role in ensuring the reliability and efficiency of electrical equipments and electronic instruments.The MAX(M is an early transition metal,A is an element from III or IV main groups,and X is carbon or/and nitrogen)phase ceramics display a unique combination of properties and may serve as an ideal reinforcement phase for electrical contact materials.The biological materials evolved in nature generally exhibit three-dimensional(3D)interpenetrating-phase architectures,which may offer useful inspiration for the architectural design of electrical contact materials.Here,a series of bi-continuous Ag-Ti_(3)SiC_(2) MAX phase composites with high ceramic contents exceeding 50 vol.%and having micron-and ultrafine-scaled 3D interpenetrating-phase architectures,wherein both constituents were continuous and mutually interspersed,were exploited by pressureless infiltration of Ag melt into partially sintered Ti_(3)SiC_(2) scaffolds.The mechanical and electrical properties as well as the friction and wear performance of the composites were investigated and revealed to be closely dependent on the ceramic contents and characteristic structural dimensions.The composites exhibited a good combination of properties with high hardness over 2.3 GPa,high flexural strength exceeding 530 MPa,decent fracture toughness over 10 MPa·m^(1/2),and good wear resistance with low wear rate at an order of 10^(-5)mm^(3)/(N·m),which were much superior compared to the counterparts made by powder metallurgy methods.In particular,the hardness,electrical conductivity,strength,and fracture toughness of the composites demonstrated a simultaneous improvement as the structure was refined from micron-to ultrafine-scales at equivalent ceramic contents.The good combination of properties along with the facile processing route makes the Ag-Ti_(3)SiC_(2)3D interpenetrating-phase composites appealing for electrical contact applications.
基金the National Natural Science Foundation of China(No.81871732)the National Key Research and Development Program of China(No.2021YFC2701402)+4 种基金the Open Research Fund of State Key Laboratory of Bioelectronics,southeast University(No.Sklb2021-k06)the Open Foundation of NHC Key Laboratory of Birth Defect for Research and Prevention(Hunan Provincial Maternal and Child Health Care Hospital)(No.KF2020007)the Open Foundation of Translational Medicine National Science and Technology Infrastructure(Shanghai)(No.TMSK-2021-141)the Open Fund from Key Laboratory of Cellular Physiology(Shanxi Medical University)Ministry of Education,China(No.CPOF202103).
文摘DNA circuits are powerful tools in various applications such as logical computation,molecular diagnosis and synthetic biology.Leakage is a major problem in constructing complex DNA circuits.It directly affects the output signal and harms the circuit’s performance significantly.In the traditional DNA circuits,the gate complex is a duplex structure.There are insufficient energy barriers to prevent spontaneous detachment of strands,resulting in a leak prone.Herein,we have developed triplex-structure based DNA circuit with ultra-low leakage and high signal-to-noise ratio(SNR).The triplex structure improves the stability in the absence of input.At the same time,the driving force of the strand displacement cascades reduces the influence of the triplex structure on the desired reaction.The SNR of the DNA circuit was increased to 695,while the desired reaction rate remained 90%of the conventional translator circuit.The triplex-structure mediated leakage prevention strategy was further tested at different temperatures and in DNA translator and seesaw circuits.We also constructed modular basic logic gates with a high efficiency and low leakage.On this basis,we further constructed triplex-structure based tertiary DNA logic circuits,and the SNR reached 295,which,to the best of our knowledge,was among the highest of the field.We believe that our scheme provides a novel,valid,and general tool for reducing leakages,and we anticipate that it will be widely adopted in DNA nanotechnology.
基金supported by the National Natural Science Foundation of China(NSFC)under Grant.Nos.51871224 and 52130002the Guangdong Basic and Applied Basic Research Foundation(2021A1515010890).
文摘The strength and thermal conductivity of compacted graphite iron(CGI)are crucial performance indicators in its engineering application.The presence of graphite in CGI significantly influences the two properties.In the previous studies,graphite in CGI was often described using two-dimensional(2D)morphology.In this study,the three-dimensional(3D)size,shape,and distribution of graphite in CGI were analyzed using X-ray tomography.Based on this,a new method is introduced to calculate the 3D vermicularity and compare it with the 2D vermicularity in terms of tensile properties and thermal conductivity.The results demonstrate that vermicular graphite exhibits greater connectivity in 3D observation compared to 2D observation.Therefore,the calculation method of 3D vermicularity is determined by considering the surface area and volume of the connected graphite.Then a linear relationship between 3 and 2D vermicularity has been observed.By comparing the correlation coefficient,it has been found that the 3D vermicularity offers a more accurate method to establish the relationship among graphite morphology,thermal conductivity and tensile property of CGI.
基金financial supported by the National Natural Science Foundation of China(Nos.51672064 and U1435206).
文摘Transpiration cooling technique is a reusable and high-efficiency thermal protection system(TPS),which is potential to improve the reusability and security of re-entry space vehicle.Relatively low density,high permeability and high porosity are general requirements for porous media of transpiration cooling systems.In this work,a new porous high entropy metal hexaboride(Y0.2Yb0.2Sm0.2Nd0.2Eu0.2)B6 is designed and prepared by the in-situ reaction/partial sintering method.Two reaction routes are designed to synthesize(Y0.2Yb0.2Sm0.2Nd0.2Eu0.2)B6,including boron thermal reduction and borocarbon thermal reduction.The as-prepared porous HE(Y0.2Yb0.2Sm0.2Nd0.2Eu0.2)B6 ceramics possess homogeneous microstructure and exhibit low density,high porosity,high compressive strength and high permeability.The combination of these properties makes porous HE(Y0.2Yb0.2Sm0.2Nd0.2Eu0.2)B6 promising as a candidate porous media for various transpiration cooling applications.
基金the National Natural Science Foundation of China(Grant Nos.51871216 and 51501190)the Opening Project of Jiangsu Province Key Laboratory of High-end Structural Materials(Grant No.hsm1801)provided by the U.S.Air Force Office of Scientific Research,under MURI grant AFSOR-FA9550-15-1-0009 to the University of California Riverside through a subcontract to the University of California Berkeley。
文摘The structures of tungsten and tungsten carbide scaffolds play a key role in determining the properties of their infiltrated composites for multifunctional applications.However,it is challenging to construct and control the architectures by means of self-assembly in W/WC systems because of their large densities.Here we present the development of unidirectionally porous architectures,with high porosities exceeding 65 vol.%,for W and WC scaffolds which in many respects reproduce the design motif of natural wood using a direct ice-templating technique.This was achieved by adjusting the viscosities of suspensions to retard sedimentation during freezing.The processing,structural characteristics and mechanical properties of the resulting scaffolds were investigated with the correlations between them explored.Quantitative relationships were established to describe their strengths based on the mechanics of cellular solids by taking into account both inter-and intra-lamellar pores.The fracture mechanisms were also identified,especially in light of the porosity.This study extends the effectiveness of the ice-templating technique for systems with large densities or particle sizes.It further provides preforms for developing new natureinspired multifunctional materials,as represented by W/WC-Cu composites.
基金project was supported by the Aeronautical Science Foundation of China (No. 2015ZE52048)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Post-weld single aging treatment(solution treatment at 510 ℃ for 1 h, water quenching,and aging at 155 ℃ for 16 h) and post-weld double aging treatment(solution treatment at 510 ℃ for 1 h, water quenching, aging at 155 ℃ for 16 h, and aging at 130 ℃ for 12 h) are carried out on Al-Cu-Li alloy joints by electron beam welding(EBW) respectively. The effects of aging treatments on microstructures and mechanical properties of welded joints are investigated. Results show that the mechanical properties of welded joints are obviously improved after both aging treatments. The strength coefficient of joints is increased from 0.64 in an as-welded condition(AW) to 0.90 after post-weld double aging treatment. Microstructure analysis shows that the precipitates of the fusion zone within grains and grain boundaries are less in the AW condition. After post-weld heat treatment(PWHT), a lot of fine needle-like phases T_1(Al_2 Cu Li) precipitate in grain boundaries of the fusion zone, and more horseshoe-shaped β' (Al_3 Zr) particles precipitate within grains. In addition,grains of the fusion zone are refined after post-weld double aging treatment, which leads to an effect of grain refinement strengthening. Consequently, the mechanical properties of welded joints are greatly improved.
基金supported by the National Natural Science Foundation of China(Grant Nos.51631008,91860201,51771204,51911530154 and U1732131)the National Science and Technology Major Project(2017-VII-0008-0101,2017-VI0003-0073 and J2019-VI-0010)the Key Deployment Projects of the Chinese Academy of Sciences(ZDRW-CN-2019-01)。
文摘The evolution of micro-pores in a single crystal nickel-based superalloy during creep at 980 ℃/220 MPa was investigated by X-ray computed tomography. Time-dependent ex-situ 3D information including the number, volume fraction, distribution and morphology of micro-pores was analyzed. The results reveal that the signifi cant formation and growth of micro-pores occur at the end of secondary/beginning of tertiary creep stage. The irregular large pores as well as high density pores located at strain concentration region are the major detrimental factors facilitating the creep damage. Creep failure is resulted from the connection of surface cracks induced by oxidation, and the internal cracks generated from growth and merging of micro-pores.
基金supported partially by the National High-Tech R&D Program of China(863 Program,No.2015AA033702)the National Basic Research Program of China(Nos.2012CB619103 and 2012CB933901)+1 种基金the National Natural Science Foundation of China(Nos.51271182 and 51501200)the Australian Research Council Discovery Project(Nos.DP110101653 and DP130103592)
文摘Electron beam melting (EBM) has been used to manufacture β-type Ti-24Nb-4Zr-8Sn porous compo- nents with 70% porosity, EBM-produced components have favorable structural features (i.e. smooth strut surfaces, fewer defects) and an (α + β)-type microstructure, similar to that subjected to aging treat- ment. EBM-produced components exhibit more than twice the strength-to-modulus ratio of porous Ti- 6A1-4V components having the same porosity. The processing-microstructure-property relationship and deformation behavior of EBM-produced components are discussed in detail. Such porous titanium com- ponents composed of non-toxic elements and having high strength-to-modulus ratio are highly attractive for biomedical applications.
基金supported by the National Key R&D Program of China(No.2020YFA0710404)the National Natural Science Foundation of China(Nos.51871216 and 52173269)the Youth Innovation Promotion Association CAS.
文摘Mg(and Mg alloys)and Ti(and Ti alloys)are two important classes of metallic implant materials which are respectively completely degradable and non-degradable after implantation.Making composites composed of them offers the promise for combining their property advantages for bone repair.Here,we present a Mg-Ti composite fabricated by pressureless infiltration of pure Mg melt into 3D printed Ti scaffold,and demonstrate a potential of the composite for use as new partially degradable and bioactive implant materials.The composite has such architecture that the Mg and Ti phases are topologically bicontinuous and mutually interspersed in 3D space,and exhibits several advantages over its constituents,such as higher strengths than as-cast pure Mg and Ti scaffold along with lower Young’s modulus than dense Ti.Additionally,the degradation of Mg phase may induce the formation and ingrowth of new bone tissues into the Ti scaffold to form mechanical interlocking between them;in this process,the Ti scaffold provides constant support and Young’s modulus adaptively decreases toward that of bone.Despite the accelerated corrosion than pure Mg,the composite remains non-cytotoxic and does not cause obvious adverse reactions after implantation as revealed by in vitro and in vivo experiments.This study may offer a new possibility for combining mechanical durability and bioactivity in implant materials,and allow for customized and targeted design of the implant.
基金the financial support of the National Key Research and Development Program of China(Nos.2016YFB0300401,2018YFF0109404 and 2016YFB0301401)the National Natural Science Foundation of China(Nos.U1860202,U1732276,50134010,51704193,51904184 and 52004156)+1 种基金the Science and Technology Commission of Shanghai Municipality(Nos.13JC14025000 and 15520711000)the China Postdoctoral Science Foundation(No.2020M671072)。
文摘Detailed three-dimensional(3 D)microtomography characterizations of inclusions in electrode matrix,mushy zone(MZ)and liquid melt film(LMF)were performed to elucidate the motion and removal behavior of inclusions in electrode tip during magnetically controlled electroslag remelting(MC-ESR)process.A transient 2 D numerical model was also built to verify the experimental results and proposed mechanisms.The number and size of inclusions exhibited an obvious increasing trend from edge to mid region in LMF,while remained almost the same in electrode matrix and MZ.The inclusions in LMF migrated from edge to mid region of LMF,accompanied with removal process.In addition,the kinetic conditions for inclusion migrating to LMF/slag interface(LSI)were enhanced during MC-ESR process,thereby improving the inclusion removal efficiency in LMF.This work highlights the 3 D characterization and motion/removal mechanisms of inclusions in electrode tip,as well as sheds new light on preparing high purity materials.
基金The authors are grateful for the financial support by National Key R&D Program of China under Grant Number 2020YFA0710404the National Natural Science Foundation of China under grant number 51871216+1 种基金the LiaoNing Revitalization Talents Program,the State Key Laboratory for Modification of Chemical Fibers and Polymer Materials at Donghua Universitythe Opening Project of Jiangsu Province Key Laboratory of High-End Structural Materials under grant number hsm 1801,the Lu Jiaxi International Team Program supported by the K.C.Wong Education Foundation and CAS,and the Youth Innovation Promotion Association CAS.
文摘The replacement of synthetic foam materials using natural biological ones is of great significance for saving energy/resources and reducing environmental pollutions.Here we characterized the microstructure and mechanical properties of natural cornstalk pith,which has a large annual output yet lacks an effective exploitation,and evaluated its feasibility for applications as a substitute for synthetic foam materials.The cornstalk pith was revealed to be a cellular material composed of closed cells elongated along the growth direction of com plant and reinforced by well-aligned vascular bundles penetrating the foam matrix.The compressive behavior is featured by a stable stress plateau which is favorable for energy absorption with its mechanical properties largely dependent on the hydration state and loading configuration.In particular,the initial dimension and mechanical properties of cornstalk pith can be effectively recovered after deformation simply by hydration treatment owing to swelling effect caused by the turgor pressure from osmosis.The cornstalk pith demonstrates an outstanding combination of low density and high energy absorption efficiency among various foam materials,specifically with its plateau stress and energy absorption comparable or even superior to those of some typical synthetic foam materials.These along with the huge resources and good biodegradability make it a promising natural energy absorbing cellular material for replacing synthetic counterparts.