Hepatocellular carcinoma(HCC) is responsible for a significant number of cancer-related deaths worldwide and its incidence is increasing. Locoregional treatments, which are precision procedures guided by imaging to sp...Hepatocellular carcinoma(HCC) is responsible for a significant number of cancer-related deaths worldwide and its incidence is increasing. Locoregional treatments, which are precision procedures guided by imaging to specifically target liver tumors, play a critical role in the management of a substantial portion of HCC cases. These therapies have become an essential element of the HCC treatment landscape, with transarterial chemoembolization(TACE)being the treatment of choice for patients with intermediate to advanced stages of the disease. Other locoregional therapies, like radiofrequency ablation, are highly effective for small, early-stage HCC. Nevertheless, the advent of targeted immunotherapy has challenged these established treatments. Tyrosine kinase inhibitors(TKIs) and immune checkpoint inhibitors(ICIs) have shown remarkable efficacy in clinical settings. However, their specific uses and the development of resistance in subsequent treatments have led clinicians to reevaluate the future direction of HCC therapy. This review concentrates on the distinct features of both systemic and novel locoregional therapies. We investigate their effects on the tumor microenvironment at the molecular level and discuss how targeted immunotherapy can be effectively integrated with locoregional therapies. We also examine research findings from retrospective studies and randomized controlled trials on various combined treatment regimens, assessing their validity to determine the future evolution of locoregional therapies within the framework of personalized, comprehensive treatment.展开更多
With the escalating flow of information and digital communication,information security has become an increasingly important issue.Traditional cryptographic methods are being threatened by advancing progress in computi...With the escalating flow of information and digital communication,information security has become an increasingly important issue.Traditional cryptographic methods are being threatened by advancing progress in computing,while physical encryption methods are favored as a viable and compelling avenue.Metasurfaces,which are known for their extraordinary ability to manipulate optical parameters at the nanoscale,exhibit significant potential for the revolution of optical devices,making them a highly promising candidate for optical encryption applications.Here,a single-sized metasurface with four independent channels is proposed for conducting steganography and multi-key information encryption.More specifically,plaintext is transformed into a ciphertext image,which is encoded into a metasurface,while the decryption key is discretely integrated into another channel within the same metasurface.Two different keys for steganographic image unveiling are also encoded into the metasurface and can be retrieved with different channels and spatial positions.This distributed multi-key encryption approach can enhance security,while strategically distributing images across distinct spatial zones serves as an additional measure to reduce the risk of information leakage.This minimalist designed metasurface,with its advantages of high information density and robust security,holds promise across applications including portable encryption,high-camouflaged image display,and high-density optical storage.展开更多
Tunable magnetic phase transition in two-dimensional materials is a fascinating subject of research.We perform first-principle calculations based on density functional theory to clarify the magnetic property of CrSeTe...Tunable magnetic phase transition in two-dimensional materials is a fascinating subject of research.We perform first-principle calculations based on density functional theory to clarify the magnetic property of CrSeTe monolayer modulated by the biaxial compressive strain.Based on the stable structure confirmed by the phonon calculation,CrSeTe is determined to be a ferromagnetic metal that undergoes a phase transition from a ferromagnetic state to an antiferromagnetic state with nearly 2.75%compressive strain.We identify the stress-magnetism behavior originating from the changes in interactions between the nearest-neighboring Cr atoms(J_(1)) and the next-nearest-neighboring Cr atoms(J_(2)).Through Monte Carlo simulation,we find that the Curie temperature of the CrSeTe monolayer is 160 K.The CrSeTe monolayer could be an intriguing platform for the two-dimensional systems and potential spintronic material.展开更多
Unifying the models for topology design and kinematic analysis has long been a desire for the research of parallel kinematic machines(PKMs). This requires that analytical description, formulation and operation for bot...Unifying the models for topology design and kinematic analysis has long been a desire for the research of parallel kinematic machines(PKMs). This requires that analytical description, formulation and operation for both finite and instantaneous motions are performed by the same mathematical tool. Based upon finite and instantaneous screw theory, a unified and systematic approach for topology design and kinematic analysis of PKMs is proposed in this paper. Using the derivative mapping between finite and instantaneous screws built in the authors’ previous work, the finite and instantaneous motions of PKMs are analytically described by the simple and non?redundant screws in quasi?vector and vector forms. And topological and parametric models of PKMs are algebraically formulated and related. These related topological and parametric models are ready to do type synthesis and kinematic analysis of PKMs under the unified framework of screw theory. In order to show the validity of the proposed approach, a kind of two?translational and three?rotational(2T3R)5?axis PKMs is taken as example. Numerous new structures of the 2T3R PKMs are synthe?sized as the results of topology design, and their Jacobian matrix is obtained easily for parameter optimization and performance evaluation. Some of the synthesized PKMs have outstanding capabilities in terms of large workspaces and flexible orientations, and have great potential for industrial applications of machining and manufacture. Among them, METROM PKM is a typical example which has attracted a lot of attention from global companies and already been developed as commercial products. The approach is a general and unified approach that can be used in the innovative design of different kinds of PKMs.展开更多
Because of their elastic links and joints,high-speed parallel robots for pick-and-place operations inevitably suffer from residual vibrations that significantly degrade their positioning accuracy.An effective approach...Because of their elastic links and joints,high-speed parallel robots for pick-and-place operations inevitably suffer from residual vibrations that significantly degrade their positioning accuracy.An effective approach based on the input shaping technique is presented in this paper for suppressing the residual vibration in these parallel robots.After addressing the design principle of an input shaper for a parallel robot with flexible actuated joints,a robust optimal input shaper is developed by considering the configuration-dependent flexible modes and minimizing the maximum percentage of residual vibration at the end-effector.The input shaper allows a good overall performance to be achieved throughout the entire workspace.Experimental results on a 4-DOF SCARA-type parallel robot show that the residual vibration of the end-effector is dramatically reduced and the dynamic positioning accuracy of the robot significantly improved.展开更多
During the 15th IFToMM World Congress on Mechanism and Machine Science(MMS)in Krakow,Poland on 30 June-4 July 2019,a special opening session has been organized to celebrate the 50-years anniversary o f IFToMM with unv...During the 15th IFToMM World Congress on Mechanism and Machine Science(MMS)in Krakow,Poland on 30 June-4 July 2019,a special opening session has been organized to celebrate the 50-years anniversary o f IFToMM with unveiling of a bronze commemorative plaque,Fig.1.展开更多
Darwin’s finches are the most classic case of evolution.Early studies on the evolution of this species were mainly based on morphology.Until now,the mitochondrial genome of Geospiza magnirostris has been sequenced an...Darwin’s finches are the most classic case of evolution.Early studies on the evolution of this species were mainly based on morphology.Until now,the mitochondrial genome of Geospiza magnirostris has been sequenced and the study explored the characteristics of the complete genome of G.magnirostris and verified the evolutionary position of it.The 13 PCGs initiated by ATN codons.The stop codons of three PCGs(ND2,COX3 and ND4)were incomplete,with only T-or TA-replacing complete form TAA or TAG.All the tRNA genes expressed a typical cloverleaf secondary structure,except for tRNA^(Ser1)(AGY),whose dihydrouridine(DHU)arm was lack and instead with a simple loop.In the sequence of the control region of G.magnirostris,we found six simple repeat tandem sequences with a total length of 42 bp.Two characteristic conserved overlapping junction(ATGCTAA)and(CAAGAAAG)were observed as reported for eight selected Passeriformes birds.A special conserved overlapping junction(ATCTTACC)involved in mitochondrial transcription termination was found between tRNA^(Tyr) and COX1 in G.magnirostris’s control region.Four most frequently used amino acids in G.magnirostris’s PCGs were Leu1(CUN),Ile,Thr,Ala.The codon usage of G.magnirostris was relatively average,and there was no particular bias.The ratio Ka/Ks results showed that G.magnirostris receives less natural selection pressure.The phylogenetic relationships and cluster analysis of relative codon usage showed that G.magnirostris and Thraupis episcopus clustered in one branch.The phylogenetic position of G.magnirostris was consistent with the traditional taxonomic of Thraupis.The results supported the conclusion that G.magnirostris belongs to the morphological classification of the family Thraupidae.展开更多
luid jet polishing(FJP)is a non-contact polishing technology that can fabricate free-form optical surfaces with sub-micron-level form accuracy and nano-level surface roughness,especially for hard and brittle materials...luid jet polishing(FJP)is a non-contact polishing technology that can fabricate free-form optical surfaces with sub-micron-level form accuracy and nano-level surface roughness,especially for hard and brittle materials.The surface generation model of FJP can be used to guide the determination and optimization of process parameters and is of great significance for understanding the evolution mechanism of surface microtopography.However,predictive models for the microscopic topography of polished surfaces are still lacking.This study established a macroscopic surface profile model for predicting 3D material removal characteristics and surface texture by combining the 3D computer fluid dynamics(CFD)simulation model and single-particle erosion mechanism.A fractal theory-based erosion model has been built to calculate the material removal caused by the erosion of a single abrasive particle on the rough surface;thus,it predicts the micro-topography and surface roughness of the polished samples.A series of polishing experiments were conducted to analyze the feasibility and accuracy of the model quantitatively and study the influence mechanism of process parameters on the material removal characteristics and surface quality.Results indicated that the models could well predict material removal and surface roughness.The prediction accuracy of the surface roughness Ra and maximum removal depth is better than 91.6%and 90%,respectively.It is also found that the material removal rate of FJP could reach 0.517 mm3/min,and the surface roughness convergence rate could reach 62.9%.展开更多
Increasing evidence suggests that deregulated RNA splicing factors play critical roles in tumorigenesis;however,their specific involvement in colon cancer remains largely unknown.Here we report that the splicing facto...Increasing evidence suggests that deregulated RNA splicing factors play critical roles in tumorigenesis;however,their specific involvement in colon cancer remains largely unknown.Here we report that the splicing factor RBM25 is overexpressed in colon cancer,and this increased expression correlates with a poor prognosis of patients with colon cancer.Functionally,RBM25 ablation suppresses the growth of colon cancer cells both in vitro and in vivo.Mechanistically,our transcriptome-wide analysis of splicing events revealed that RBM25 regulates a large number of cancer-related alternative splicing events across the human genome in colon cancer.Particularly,RBM25 regulates the splicing of MNK2 by interacting with the poly G rich region in exon 14a,thereby inhibiting the selection of the proximal 3'splice site(ss),resulting in the production of the oncogenic short isoform,MNK2b.Knockdown of RBM25 leads to an increase in the MNK2a isoform and a decrease in the MNK2b isoform.Importantly,re-expression of MNK2b or blocking the 3′ss of the alternative exon 14a with ASO partially reverses the RBM25 knockdown mediated tumor suppression.Moreover,MNK2b levels were significantly increased in colon cancer tissues,which is positively correlated with the expression level of RBM25.Collectively,our findings uncover the critical role of RBM25 as a key splicing factor in colon cancer,suggesting its potential as a prognostic marker and therapeutic target.展开更多
Vortex light is a unique beam characterized by a spiral phase as it propagates. A fundamental parameter of vortex light is the topological charge, which determines the amount of angular momentum and plays a crucial ro...Vortex light is a unique beam characterized by a spiral phase as it propagates. A fundamental parameter of vortex light is the topological charge, which determines the amount of angular momentum and plays a crucial role in tailoring its behavior. However, conventional measurement methods for determining the topological charge, such as those based on interference and phase modulation, tend to be intricate and complex. In this regard, a labeled vortex beam generator is proposed, composed of a metasurface with a single-celled configuration. When the metasurface is illuminated by light of the designed wavelength, the outgoing light exhibits a vortex structure. Furthermore, the topological charge numbers can be directly observed with distinct labeled patterns when the metasurface is placed in an orthogonal-polarized optical path. With advantages such as ultra-compactness, high robustness, and exceptional precision, the proposed metasurface exhibits significant potential for applications in optical communication, light manipulation, optical sensing, etc.展开更多
Recently,the development of chemodynamic therapy(CDT)offers a potential approach for fighting bacteria and treating infectious diseases,in which those CDT nanoagents can catalyze the generation of hydroxyl radicals(&#...Recently,the development of chemodynamic therapy(CDT)offers a potential approach for fighting bacteria and treating infectious diseases,in which those CDT nanoagents can catalyze the generation of hydroxyl radicals(·OH)to destroy bacteria.In this work,to improve the efficiency of CDT,we have designed a new kind of metformin(Met)-capped two-dimensional Cu_(2)(OH)_(3)Cl nanosheets(CuOHCl-Met NSs)with good monodispersity,highly positive charge,and good biocompatibility for improving antibacterial effect and accelerating wound healing.With the capped Met,CuOHCl-Met NSs can effectively kill bacteria under a low concentration(6μg·mL^(−1))and a short treatment time(in 15 min),showing great advantages over the counterpart without Met.In vivo results demonstrated that CuOHCl-Met NSs accelerated the tissue regeneration of staphylococcus aureus-infected dermal wounds.This study provides a new pathway for improving efficiency of CDT nanoagent through using old drug.展开更多
With the development of engineered nanomaterials and nanomedicines,uti-lization of nanomaterials to generate excessive reactive oxygen species underexogenous ultrasound(US)irradiation for realizing disease therapy,nam...With the development of engineered nanomaterials and nanomedicines,uti-lization of nanomaterials to generate excessive reactive oxygen species underexogenous ultrasound(US)irradiation for realizing disease therapy,namelysonodynamic therapy(SDT),has attracted widespread attention.Comparedwith traditional photodynamic therapy,US shows deeper tissue penetration toreach deep-seated location.However,the development of high-efficiencysonosensitizers remains one of the gravest challenges in current relatedresearch and future clinical application.Latterly,benefiting from the piezo-tronic and piezo-phototronic effects,novel sonosensitizers based on piezo-electric semiconductor(PS)nanomaterials have exhibited inspiring applicationprospects in SDT.In this review,we outline the structures and physico-chemical properties of PS nanomaterials that has potential applications inSDT,and introduce the presumed mechanisms of PS nanomaterials in SDT.Then,the latest research progress of PS nanomaterials as sonosensitizers incancer therapy and antibacterial applications are summarized.Finally,theexisting challenges and future development trends in this field are prospected.展开更多
The mobile hybrid machining robot has a very bright application prospect in the field of high-efficiency and high-precision machining of large aerospace structures.However,an inappropriate base placement may make the ...The mobile hybrid machining robot has a very bright application prospect in the field of high-efficiency and high-precision machining of large aerospace structures.However,an inappropriate base placement may make the robot encounter a singular configuration,or even fail to complete the entire machining task due to unreachability.In addition to considering the two constraints of reachability and non-singularity,this paper also optimizes the robot base placement with stiffness as the goal to improve the machining quality.First of all,starting from the structure of the robot,the reachability and nonsingularity constraints are transformed into a simple geometric constraint imposed on the base placement:feasible base placement area.Then,genetic algorithm is used to search for the base placement with near optimal stiffness(near optimal base placement for short)in the feasible base placement area.Finally,multiple controlled experiments were carried out by taking the milling of a protuberance on the spacecraft cabin as an example.It is found that the calculated optimal base placement meets all the constraints and that the machining quality was indeed improved.In addition,compared with simple genetic algorithm,it is proved that the feasible base placement area method can shorten the running time of the whole program.展开更多
Electrochemical system with electro-Fenton reaction is an effective pathway for oxidative degradation of refractory organic pollutants for water treatment.However,the method is limited by the low catalytic efficiency ...Electrochemical system with electro-Fenton reaction is an effective pathway for oxidative degradation of refractory organic pollutants for water treatment.However,the method is limited by the low catalytic efficiency and high electrical cost in practical applications.This work presents a self-powered and high-efficient electrochemical system for water treatment including pollutant degradation and bacterial inactivation,which is composed of a self-powered triboelectric nanogenerator(TENG)converting mechanical energy into electrical energy,a power management circuit integrated with a supercapacitor to store the harvesting electrical energy temporarily,and an electrochemical setup integrated with two-dimentional Co(OH)_(2)/Pt nanosheet as electrocatalyst.The nanocatalyst,ultrafine Pt nanoparticles(Pt NPs)loaded on Co(OH)_(2) nanosheet(Co(OH)_(2)/Pt),is synthesized by a facile one step hydrothermal reaction without any surfactant,which can improve H_(2)O_(2)and hydroxyl radical production via redox reaction.This self-powered electrocatalytic system is able to degrade nearly 100%of organic pollutant within 100 min,and efficiently kill bacteria.This work shows great potential to develop high-efficient and self-powered electrochemical water treatment system through integrating TENG and nanocatalyst.展开更多
Although research interest in aqueous metal-sulfur batteries(AMSs)has surged due to their intrinsic low cost and high capacity,the practical application of AMSs remains a considerable challenge because of the restrict...Although research interest in aqueous metal-sulfur batteries(AMSs)has surged due to their intrinsic low cost and high capacity,the practical application of AMSs remains a considerable challenge because of the restrictive cycling stability.To circumvent this issue,we propose an innovative and simple pre-copper strategy to realize a high-durability aqueous Cu-S battery.The precopper strategy can effectively promote a stable metal dissolution/deposition,compensate for charge carriers,and facilitate reaction kinetics during the subsequent process.As a result,the aqueous Cu-S battery when coupled with S-decorated porous Ti_(3)C_(2)(S-d-Ti_(3)C_(2))exhibits excellent electrochemical performance,delivering a highly reversible capacity of 1805.4 mAh·g^(-1)in the initial cycle at 0.8 A·g^(-1),impressive cycling stability with 90.2%capacity retention over 800 cycles,and ultralow polarization~0.08 V even at a high current density of 3.1 A·g^(-1).The findings obtained in this work could pave the way for the design of highperformance sulfur-based aqueous batteries,which fill the vacancy of the necessary metal anode,delivering merits in both cost and cycle life.展开更多
With the rapid development of photo-responsive nanomaterials,photo-triggered therapeutic strategies such as photothermal therapy(PTT)and photodynamic therapy(PDT)have been new alternatives to current cancer therapeuti...With the rapid development of photo-responsive nanomaterials,photo-triggered therapeutic strategies such as photothermal therapy(PTT)and photodynamic therapy(PDT)have been new alternatives to current cancer therapeutic methods.Herein,we have fabricated oxygen vacancy-engineered BaTiO_(3)(BTO-Ov)nanoparticles(NPs)for near-infrared(NIR)light-triggered PTT,PDT,and catalytic therapy cooperatively for significantly improving cancer therapy.Compared to pristine BaTiO_(3)nanoparticles,BTO-Ov has stronger NIR light absorption and narrower band gap structure,which results in superior photothermal conversion and superoxide radical generation capabilities through PTT and PDT.Meanwhile,due to the existence of Ti^(3+),BTO-Ov also exhibits peroxidase(POD)-like activity to produce hydroxyl radical under tumor environment,which can be further improved under 808 nm light irradiation.Both in vitro and in vivo results demonstrate that such a multifunctional therapeutic nanoplatform can achieve a high therapeutic efficacy triggered by a single NIR light irradiation.The defect engineering strategy can be used as a general approach to fabricate multifunctional cancer therapeutic nanoplatform.展开更多
The high-voltage power source is one of the important research directions of triboelectric nanogenerator(TENG).In this paper,a high-voltage output TENG(HVO-TENG)is proposed with direct current/alternating current(DC/A...The high-voltage power source is one of the important research directions of triboelectric nanogenerator(TENG).In this paper,a high-voltage output TENG(HVO-TENG)is proposed with direct current/alternating current(DC/AC)optimal combination method for wind energy harvesting.Through the optimal design of a direct current generation unit(DCGU)and an alternating current generation unit(ACGU),the HVO-TENG can produce DC voltage of 21.5 kV and AC voltage of 200 V,simultaneously.The HVOTENG can continuously illuminate more than 6,000 light emitting diodes(LEDs),which is enough to drive more possible applications of TENG.Besides,this paper explored application experiments on HVO-TENG.Demonstrative experiments indicate that the high-voltage DC output is used for producing ozone,while the AC output can light up ultraviolet(UV)LEDs.The HVOTENG can increase the ozone concentration(C)in an airtight container to 3 parts per million(ppm)after 7 h and continuously light up UV LEDs.All these demonstrations verify that the HVO-TENG has important guiding significance for designing high performance TENG.展开更多
文摘Hepatocellular carcinoma(HCC) is responsible for a significant number of cancer-related deaths worldwide and its incidence is increasing. Locoregional treatments, which are precision procedures guided by imaging to specifically target liver tumors, play a critical role in the management of a substantial portion of HCC cases. These therapies have become an essential element of the HCC treatment landscape, with transarterial chemoembolization(TACE)being the treatment of choice for patients with intermediate to advanced stages of the disease. Other locoregional therapies, like radiofrequency ablation, are highly effective for small, early-stage HCC. Nevertheless, the advent of targeted immunotherapy has challenged these established treatments. Tyrosine kinase inhibitors(TKIs) and immune checkpoint inhibitors(ICIs) have shown remarkable efficacy in clinical settings. However, their specific uses and the development of resistance in subsequent treatments have led clinicians to reevaluate the future direction of HCC therapy. This review concentrates on the distinct features of both systemic and novel locoregional therapies. We investigate their effects on the tumor microenvironment at the molecular level and discuss how targeted immunotherapy can be effectively integrated with locoregional therapies. We also examine research findings from retrospective studies and randomized controlled trials on various combined treatment regimens, assessing their validity to determine the future evolution of locoregional therapies within the framework of personalized, comprehensive treatment.
基金supported by the National Natural Science Foundation of China(12204359 and 12174292)the China Postdoctoral Science Foundation(2022TQ0243 and 2022M722448)+1 种基金the Natural Science Foundation of Hubei Province(2022CFB641)the Natural Science Foundation of Jiangsu Province(BK20231210).
文摘With the escalating flow of information and digital communication,information security has become an increasingly important issue.Traditional cryptographic methods are being threatened by advancing progress in computing,while physical encryption methods are favored as a viable and compelling avenue.Metasurfaces,which are known for their extraordinary ability to manipulate optical parameters at the nanoscale,exhibit significant potential for the revolution of optical devices,making them a highly promising candidate for optical encryption applications.Here,a single-sized metasurface with four independent channels is proposed for conducting steganography and multi-key information encryption.More specifically,plaintext is transformed into a ciphertext image,which is encoded into a metasurface,while the decryption key is discretely integrated into another channel within the same metasurface.Two different keys for steganographic image unveiling are also encoded into the metasurface and can be retrieved with different channels and spatial positions.This distributed multi-key encryption approach can enhance security,while strategically distributing images across distinct spatial zones serves as an additional measure to reduce the risk of information leakage.This minimalist designed metasurface,with its advantages of high information density and robust security,holds promise across applications including portable encryption,high-camouflaged image display,and high-density optical storage.
基金the National Natural Science Foundation of China(Grant Nos.61874060,U1932159,and 61911530220)the Natural Science Foundation of Jiangsu Province(Grant No.BK20181388)+3 种基金the Natural Science Research of Jiangsu Higher Education Institutions of China(Grant No.21KJD140005)the Foundation of Nanjing University of Posts and Telecommunications(NUPT)‘1311 Talent Program’supported by the Natural Science Foundation of Jiangsu Province(Grant No.20KJB430010)NUPTSF(Grant No.NY219164)。
文摘Tunable magnetic phase transition in two-dimensional materials is a fascinating subject of research.We perform first-principle calculations based on density functional theory to clarify the magnetic property of CrSeTe monolayer modulated by the biaxial compressive strain.Based on the stable structure confirmed by the phonon calculation,CrSeTe is determined to be a ferromagnetic metal that undergoes a phase transition from a ferromagnetic state to an antiferromagnetic state with nearly 2.75%compressive strain.We identify the stress-magnetism behavior originating from the changes in interactions between the nearest-neighboring Cr atoms(J_(1)) and the next-nearest-neighboring Cr atoms(J_(2)).Through Monte Carlo simulation,we find that the Curie temperature of the CrSeTe monolayer is 160 K.The CrSeTe monolayer could be an intriguing platform for the two-dimensional systems and potential spintronic material.
基金Supported by National Natural Science Foundation of China(Grant No.51675366)Tianjin Research Program of Application Foundation and Advanced Technology(Grant Nos.16JCYBJC19300,15JCZDJC38900)
文摘Unifying the models for topology design and kinematic analysis has long been a desire for the research of parallel kinematic machines(PKMs). This requires that analytical description, formulation and operation for both finite and instantaneous motions are performed by the same mathematical tool. Based upon finite and instantaneous screw theory, a unified and systematic approach for topology design and kinematic analysis of PKMs is proposed in this paper. Using the derivative mapping between finite and instantaneous screws built in the authors’ previous work, the finite and instantaneous motions of PKMs are analytically described by the simple and non?redundant screws in quasi?vector and vector forms. And topological and parametric models of PKMs are algebraically formulated and related. These related topological and parametric models are ready to do type synthesis and kinematic analysis of PKMs under the unified framework of screw theory. In order to show the validity of the proposed approach, a kind of two?translational and three?rotational(2T3R)5?axis PKMs is taken as example. Numerous new structures of the 2T3R PKMs are synthe?sized as the results of topology design, and their Jacobian matrix is obtained easily for parameter optimization and performance evaluation. Some of the synthesized PKMs have outstanding capabilities in terms of large workspaces and flexible orientations, and have great potential for industrial applications of machining and manufacture. Among them, METROM PKM is a typical example which has attracted a lot of attention from global companies and already been developed as commercial products. The approach is a general and unified approach that can be used in the innovative design of different kinds of PKMs.
基金Supported by National Natural Science Foundation of China(Grant No.51721003)State Key Laboratory of Robotics and System(HIT)(Grant No.SKLRS–2018–KF-09)。
文摘Because of their elastic links and joints,high-speed parallel robots for pick-and-place operations inevitably suffer from residual vibrations that significantly degrade their positioning accuracy.An effective approach based on the input shaping technique is presented in this paper for suppressing the residual vibration in these parallel robots.After addressing the design principle of an input shaper for a parallel robot with flexible actuated joints,a robust optimal input shaper is developed by considering the configuration-dependent flexible modes and minimizing the maximum percentage of residual vibration at the end-effector.The input shaper allows a good overall performance to be achieved throughout the entire workspace.Experimental results on a 4-DOF SCARA-type parallel robot show that the residual vibration of the end-effector is dramatically reduced and the dynamic positioning accuracy of the robot significantly improved.
文摘During the 15th IFToMM World Congress on Mechanism and Machine Science(MMS)in Krakow,Poland on 30 June-4 July 2019,a special opening session has been organized to celebrate the 50-years anniversary o f IFToMM with unveiling of a bronze commemorative plaque,Fig.1.
基金The study was supported by National Natural Science Foundation of China[Grant No.U20A20118]College Students’Innovative Entrepreneurial Training Plan Program of Shannxi Province[Grant No.S202010712295].
文摘Darwin’s finches are the most classic case of evolution.Early studies on the evolution of this species were mainly based on morphology.Until now,the mitochondrial genome of Geospiza magnirostris has been sequenced and the study explored the characteristics of the complete genome of G.magnirostris and verified the evolutionary position of it.The 13 PCGs initiated by ATN codons.The stop codons of three PCGs(ND2,COX3 and ND4)were incomplete,with only T-or TA-replacing complete form TAA or TAG.All the tRNA genes expressed a typical cloverleaf secondary structure,except for tRNA^(Ser1)(AGY),whose dihydrouridine(DHU)arm was lack and instead with a simple loop.In the sequence of the control region of G.magnirostris,we found six simple repeat tandem sequences with a total length of 42 bp.Two characteristic conserved overlapping junction(ATGCTAA)and(CAAGAAAG)were observed as reported for eight selected Passeriformes birds.A special conserved overlapping junction(ATCTTACC)involved in mitochondrial transcription termination was found between tRNA^(Tyr) and COX1 in G.magnirostris’s control region.Four most frequently used amino acids in G.magnirostris’s PCGs were Leu1(CUN),Ile,Thr,Ala.The codon usage of G.magnirostris was relatively average,and there was no particular bias.The ratio Ka/Ks results showed that G.magnirostris receives less natural selection pressure.The phylogenetic relationships and cluster analysis of relative codon usage showed that G.magnirostris and Thraupis episcopus clustered in one branch.The phylogenetic position of G.magnirostris was consistent with the traditional taxonomic of Thraupis.The results supported the conclusion that G.magnirostris belongs to the morphological classification of the family Thraupidae.
基金the National Natural Science Foundation of China(No.51905376).
文摘luid jet polishing(FJP)is a non-contact polishing technology that can fabricate free-form optical surfaces with sub-micron-level form accuracy and nano-level surface roughness,especially for hard and brittle materials.The surface generation model of FJP can be used to guide the determination and optimization of process parameters and is of great significance for understanding the evolution mechanism of surface microtopography.However,predictive models for the microscopic topography of polished surfaces are still lacking.This study established a macroscopic surface profile model for predicting 3D material removal characteristics and surface texture by combining the 3D computer fluid dynamics(CFD)simulation model and single-particle erosion mechanism.A fractal theory-based erosion model has been built to calculate the material removal caused by the erosion of a single abrasive particle on the rough surface;thus,it predicts the micro-topography and surface roughness of the polished samples.A series of polishing experiments were conducted to analyze the feasibility and accuracy of the model quantitatively and study the influence mechanism of process parameters on the material removal characteristics and surface quality.Results indicated that the models could well predict material removal and surface roughness.The prediction accuracy of the surface roughness Ra and maximum removal depth is better than 91.6%and 90%,respectively.It is also found that the material removal rate of FJP could reach 0.517 mm3/min,and the surface roughness convergence rate could reach 62.9%.
基金supported by the National Key Research and Development Program of China(2022YFA1104002,2023YFE0117500)the National Natural Science Foundation of China(82225034,82273427)+1 种基金the Science and Technology Innovation Talent Support Program of Dalian(2022RJ15,2022JJ11CG009)the Liaoning Revitalization Talents Program(XLYC2202027)。
文摘Increasing evidence suggests that deregulated RNA splicing factors play critical roles in tumorigenesis;however,their specific involvement in colon cancer remains largely unknown.Here we report that the splicing factor RBM25 is overexpressed in colon cancer,and this increased expression correlates with a poor prognosis of patients with colon cancer.Functionally,RBM25 ablation suppresses the growth of colon cancer cells both in vitro and in vivo.Mechanistically,our transcriptome-wide analysis of splicing events revealed that RBM25 regulates a large number of cancer-related alternative splicing events across the human genome in colon cancer.Particularly,RBM25 regulates the splicing of MNK2 by interacting with the poly G rich region in exon 14a,thereby inhibiting the selection of the proximal 3'splice site(ss),resulting in the production of the oncogenic short isoform,MNK2b.Knockdown of RBM25 leads to an increase in the MNK2a isoform and a decrease in the MNK2b isoform.Importantly,re-expression of MNK2b or blocking the 3′ss of the alternative exon 14a with ASO partially reverses the RBM25 knockdown mediated tumor suppression.Moreover,MNK2b levels were significantly increased in colon cancer tissues,which is positively correlated with the expression level of RBM25.Collectively,our findings uncover the critical role of RBM25 as a key splicing factor in colon cancer,suggesting its potential as a prognostic marker and therapeutic target.
基金This study is supported by National Key Research and Development Program of China(2021YFE0205800)National Natural Science Foundation of China(12204359,62205252)+2 种基金China Postdoctoral Science Foundation(2022TQ0243,2022M722448)the Fundamental Research Funds for the Central Universities(2042022kf1013)Natural Science Foundation of Hubei Province(2022CFB641).
文摘Vortex light is a unique beam characterized by a spiral phase as it propagates. A fundamental parameter of vortex light is the topological charge, which determines the amount of angular momentum and plays a crucial role in tailoring its behavior. However, conventional measurement methods for determining the topological charge, such as those based on interference and phase modulation, tend to be intricate and complex. In this regard, a labeled vortex beam generator is proposed, composed of a metasurface with a single-celled configuration. When the metasurface is illuminated by light of the designed wavelength, the outgoing light exhibits a vortex structure. Furthermore, the topological charge numbers can be directly observed with distinct labeled patterns when the metasurface is placed in an orthogonal-polarized optical path. With advantages such as ultra-compactness, high robustness, and exceptional precision, the proposed metasurface exhibits significant potential for applications in optical communication, light manipulation, optical sensing, etc.
基金supported by the National Natural Science Foundation of China(Nos.82072065 and 81471784).
文摘Recently,the development of chemodynamic therapy(CDT)offers a potential approach for fighting bacteria and treating infectious diseases,in which those CDT nanoagents can catalyze the generation of hydroxyl radicals(·OH)to destroy bacteria.In this work,to improve the efficiency of CDT,we have designed a new kind of metformin(Met)-capped two-dimensional Cu_(2)(OH)_(3)Cl nanosheets(CuOHCl-Met NSs)with good monodispersity,highly positive charge,and good biocompatibility for improving antibacterial effect and accelerating wound healing.With the capped Met,CuOHCl-Met NSs can effectively kill bacteria under a low concentration(6μg·mL^(−1))and a short treatment time(in 15 min),showing great advantages over the counterpart without Met.In vivo results demonstrated that CuOHCl-Met NSs accelerated the tissue regeneration of staphylococcus aureus-infected dermal wounds.This study provides a new pathway for improving efficiency of CDT nanoagent through using old drug.
基金supported by the National Natural Science Foundation of China(82072065 and 81471784)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA16021103)+1 种基金the Fundamental Research Funds for the Central Universities(E2EG6802X2 and E2E46801)the National Youth Talent Support Program.
基金Strategic Priority Research Program of the Chinese Academy of Sciences,Grant/Award Number:XDA16021103National Natural Science Foundation of China,Grant/Award Numbers:81471784,82072065+1 种基金National Youth Talent Support ProgramFundamental Research Funds for the Central Universities,Grant/Award Number:E2EG6802X2。
文摘With the development of engineered nanomaterials and nanomedicines,uti-lization of nanomaterials to generate excessive reactive oxygen species underexogenous ultrasound(US)irradiation for realizing disease therapy,namelysonodynamic therapy(SDT),has attracted widespread attention.Comparedwith traditional photodynamic therapy,US shows deeper tissue penetration toreach deep-seated location.However,the development of high-efficiencysonosensitizers remains one of the gravest challenges in current relatedresearch and future clinical application.Latterly,benefiting from the piezo-tronic and piezo-phototronic effects,novel sonosensitizers based on piezo-electric semiconductor(PS)nanomaterials have exhibited inspiring applicationprospects in SDT.In this review,we outline the structures and physico-chemical properties of PS nanomaterials that has potential applications inSDT,and introduce the presumed mechanisms of PS nanomaterials in SDT.Then,the latest research progress of PS nanomaterials as sonosensitizers incancer therapy and antibacterial applications are summarized.Finally,theexisting challenges and future development trends in this field are prospected.
基金supported by National Natural Science Foundation of China(Nos.91948301,52175025 and 51721003).
文摘The mobile hybrid machining robot has a very bright application prospect in the field of high-efficiency and high-precision machining of large aerospace structures.However,an inappropriate base placement may make the robot encounter a singular configuration,or even fail to complete the entire machining task due to unreachability.In addition to considering the two constraints of reachability and non-singularity,this paper also optimizes the robot base placement with stiffness as the goal to improve the machining quality.First of all,starting from the structure of the robot,the reachability and nonsingularity constraints are transformed into a simple geometric constraint imposed on the base placement:feasible base placement area.Then,genetic algorithm is used to search for the base placement with near optimal stiffness(near optimal base placement for short)in the feasible base placement area.Finally,multiple controlled experiments were carried out by taking the milling of a protuberance on the spacecraft cabin as an example.It is found that the calculated optimal base placement meets all the constraints and that the machining quality was indeed improved.In addition,compared with simple genetic algorithm,it is proved that the feasible base placement area method can shorten the running time of the whole program.
基金supported by the Strategic Priority Research Program of The Chinese Academy of Sciences(No.XDA16021103)National Natural Science Foundation(Nos.82072065 and 81471784)+1 种基金the National Youth Talent Support Program and the China Postdoctoral Science Foundation(Nos.BX2021299 and 2021M703166)the Fundamental Research Funds for the Central Universities.
文摘Electrochemical system with electro-Fenton reaction is an effective pathway for oxidative degradation of refractory organic pollutants for water treatment.However,the method is limited by the low catalytic efficiency and high electrical cost in practical applications.This work presents a self-powered and high-efficient electrochemical system for water treatment including pollutant degradation and bacterial inactivation,which is composed of a self-powered triboelectric nanogenerator(TENG)converting mechanical energy into electrical energy,a power management circuit integrated with a supercapacitor to store the harvesting electrical energy temporarily,and an electrochemical setup integrated with two-dimentional Co(OH)_(2)/Pt nanosheet as electrocatalyst.The nanocatalyst,ultrafine Pt nanoparticles(Pt NPs)loaded on Co(OH)_(2) nanosheet(Co(OH)_(2)/Pt),is synthesized by a facile one step hydrothermal reaction without any surfactant,which can improve H_(2)O_(2)and hydroxyl radical production via redox reaction.This self-powered electrocatalytic system is able to degrade nearly 100%of organic pollutant within 100 min,and efficiently kill bacteria.This work shows great potential to develop high-efficient and self-powered electrochemical water treatment system through integrating TENG and nanocatalyst.
基金We appreciate support from the National Natural Science Foundation of China(Nos.22005315 and22179109)Central Universities Fundamental Research Funds(No.SWU-KR22002)Chongqing Natural Science Foundation(No.cstc2020jcyjzdxmX0010).
文摘Although research interest in aqueous metal-sulfur batteries(AMSs)has surged due to their intrinsic low cost and high capacity,the practical application of AMSs remains a considerable challenge because of the restrictive cycling stability.To circumvent this issue,we propose an innovative and simple pre-copper strategy to realize a high-durability aqueous Cu-S battery.The precopper strategy can effectively promote a stable metal dissolution/deposition,compensate for charge carriers,and facilitate reaction kinetics during the subsequent process.As a result,the aqueous Cu-S battery when coupled with S-decorated porous Ti_(3)C_(2)(S-d-Ti_(3)C_(2))exhibits excellent electrochemical performance,delivering a highly reversible capacity of 1805.4 mAh·g^(-1)in the initial cycle at 0.8 A·g^(-1),impressive cycling stability with 90.2%capacity retention over 800 cycles,and ultralow polarization~0.08 V even at a high current density of 3.1 A·g^(-1).The findings obtained in this work could pave the way for the design of highperformance sulfur-based aqueous batteries,which fill the vacancy of the necessary metal anode,delivering merits in both cost and cycle life.
基金the National Nature Science Foundation of China(Nos.82072065 and 81471784)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA16021103)the National Youth Talent Support Program.
文摘With the rapid development of photo-responsive nanomaterials,photo-triggered therapeutic strategies such as photothermal therapy(PTT)and photodynamic therapy(PDT)have been new alternatives to current cancer therapeutic methods.Herein,we have fabricated oxygen vacancy-engineered BaTiO_(3)(BTO-Ov)nanoparticles(NPs)for near-infrared(NIR)light-triggered PTT,PDT,and catalytic therapy cooperatively for significantly improving cancer therapy.Compared to pristine BaTiO_(3)nanoparticles,BTO-Ov has stronger NIR light absorption and narrower band gap structure,which results in superior photothermal conversion and superoxide radical generation capabilities through PTT and PDT.Meanwhile,due to the existence of Ti^(3+),BTO-Ov also exhibits peroxidase(POD)-like activity to produce hydroxyl radical under tumor environment,which can be further improved under 808 nm light irradiation.Both in vitro and in vivo results demonstrate that such a multifunctional therapeutic nanoplatform can achieve a high therapeutic efficacy triggered by a single NIR light irradiation.The defect engineering strategy can be used as a general approach to fabricate multifunctional cancer therapeutic nanoplatform.
基金National Key R&D Project from the Minister of Science and Technology(Nos.2016YFA0202701 and 2016YFA0202704)the Beijing Municipal Science and Technology Commission(No.Z171100002017017).
文摘The high-voltage power source is one of the important research directions of triboelectric nanogenerator(TENG).In this paper,a high-voltage output TENG(HVO-TENG)is proposed with direct current/alternating current(DC/AC)optimal combination method for wind energy harvesting.Through the optimal design of a direct current generation unit(DCGU)and an alternating current generation unit(ACGU),the HVO-TENG can produce DC voltage of 21.5 kV and AC voltage of 200 V,simultaneously.The HVOTENG can continuously illuminate more than 6,000 light emitting diodes(LEDs),which is enough to drive more possible applications of TENG.Besides,this paper explored application experiments on HVO-TENG.Demonstrative experiments indicate that the high-voltage DC output is used for producing ozone,while the AC output can light up ultraviolet(UV)LEDs.The HVOTENG can increase the ozone concentration(C)in an airtight container to 3 parts per million(ppm)after 7 h and continuously light up UV LEDs.All these demonstrations verify that the HVO-TENG has important guiding significance for designing high performance TENG.
