Zinc–air batteries(ZABs)are expected to be some of the most promising power sources for wearable and portable electronic devices and have received widespread research interest.As an ion conductor connecting anodes an...Zinc–air batteries(ZABs)are expected to be some of the most promising power sources for wearable and portable electronic devices and have received widespread research interest.As an ion conductor connecting anodes and cathodes,the electrolyte is critical for the overall performance of ZABs(e.g.,energy density,rechargeability,and operating voltage).Compared with liquid electrolytes,polymer-based electrolytes have superior characteristics for ZABs,such as negligible electrolyte leakage,three-phase interface stabilization,and dendrite suppression.In this perspective,we focus on recent progress in polymer-based electrolytes for ZABs.After a brief introduction to ZABs and electrolytes,we emphasize the development of polymer-based electrolytes in terms of their intrinsic properties and interfacial chemistry.Finally,challenges and viable strategies are proposed for polymer-based electrolytes in ZABs.We hope that this work will provide useful guidance to spur the development of high-performance ZABs based on advanced polymer-based electrolytes.展开更多
Fuel cells have attracted extensive attention due to their high conversion efficiency and environmental friendliness.However,their wider application is limited by the poor activity and high cost of platinum(Pt),which ...Fuel cells have attracted extensive attention due to their high conversion efficiency and environmental friendliness.However,their wider application is limited by the poor activity and high cost of platinum(Pt),which is widely used as the cathode catalyst to overcome the slow kinetics associated with oxygen reduction reaction(ORR).Pt‐based composites with one‐dimensional(1D)nanoarchitectures demonstrate great advantages towards efficient ORR catalysis.This review focuses on the recent advancements in the design and synthesis of 1D Pt‐based ORR catalysts.After introducing the fundamental ORR mechanism and the advanced 1D architectures,their synthesis strategies(template‐based and template‐free methods)are discoursed.Subsequently,their morphology and structure optimization are highlighted,followed by the superstructure assembly using 1D Pt‐based blocks.Finally,the challenges and perspectives on the synthesis innovation,structure design,physical characterization,and theoretical investigations are proposed for 1D Pt‐based ORR nanocatalysts.We anticipate this study will inspire more research endeavors on efficient ORR nanocatalysts in fuel cell application.展开更多
Oxygen electrocatalysts are of great importance for the air electrode in zinc-air batteries(ZABs).Owing to the high specific surface area,controllable pore size and unsaturated metal active sites,metal-organic framewo...Oxygen electrocatalysts are of great importance for the air electrode in zinc-air batteries(ZABs).Owing to the high specific surface area,controllable pore size and unsaturated metal active sites,metal-organic frameworks(MOFs)derivatives have been widely studied as oxygen electrocatalysts in ZABs.To date,many strategies have been developed to generate efficient oxygen electrocatalysts from MOFs for improving the performance of ZABs.In this review,the latest progress of the MOF-derived non-noble metal-oxygen electrocatalysts in ZABs is reviewed.The performance of these MOF-derived catalysts toward oxygen reduction,and oxygen evolution reactions is discussed based on the categories of metal-free carbon materials,single-atom catalysts,metal cluster/carbon composites and metal compound/carbon composites.Moreover,we provide a comprehensive overview on the design strategies of various MOF-derived non-noble metal-oxygen electrocatalysts and their structure-performance relationship.Finally,the challenges and perspectives are provided for further advancing the MOF-derived oxygen electrocatalysts in ZABs.展开更多
The sensitivity problem to mesh distortion and the low accuracy problem of the stress solutions are two inherent difficulties in the finite element method.By applying the fundamental analytical solutions (in global Ca...The sensitivity problem to mesh distortion and the low accuracy problem of the stress solutions are two inherent difficulties in the finite element method.By applying the fundamental analytical solutions (in global Cartesian coordinates) to the Airy stress function of the anisotropic materials,8-and 12-node plane quadrilateral hybrid stress-function (HS-F) elements are successfully developed based on the principle of the minimum complementary energy.Numerical results show that the present new elements exhibit much better and more robust performance in both displacement and stress solutions than those obtained from other models.They can still perform very well even when the element shapes degenerate into a triangle and a concave quadrangle.It is also demonstrated that the proposed construction procedure is an effective way for developing shape-free finite element models which can completely overcome the sensitivity problem to mesh distortion and can produce highly accurate stress solutions.展开更多
Blocking the programmed death-ligand 1(PD-L1)on tumor cells with monoclonal antibody therapy has emerged as powerful weapon in cancer immunotherapy.However,only a minority of patients presented immune responses in cli...Blocking the programmed death-ligand 1(PD-L1)on tumor cells with monoclonal antibody therapy has emerged as powerful weapon in cancer immunotherapy.However,only a minority of patients presented immune responses in clinical trials.To develop an alternative treatment method based on immune checkpoint blockade,we designed a novel and efficient CRISPR-Cas9 genome editing system delivered by cationic copolymer aPBAE to downregulate PD-L1 expression on tumor cells via specifically knocking out Cyclin-dependent kinase 5(Cdk5)gene in vivo.The expression of PD-L1 on tumor cells was significantly attenuated by knocking out Cdk5,leading to effective tumor growth inhibition in murine melanoma and lung metastasis suppression in triple-negative breast cancer.Importantly,we demonstrated that aPBAE/Cas9-Cdk5 treatment elicited strong T cell-mediated immune responses in tumor microenvironment that the population of CD8^+T cells was significantly increased while regulatory T cells(Tregs)was decreased.It may be the first case to exhibit direct in vivo PD-L1 downregulation via CRISPR-Cas9 genome editing technology for cancer therapy.It will provide promising strategy for preclinical antitumor treatment through the combination of nanotechnology and genome engineering.展开更多
In this paper,two new guidance laws based on differential game theory are proposed and investigated for the attacker in an attacker-defender-target scenario.The conditions for the attacker winning the game are analyze...In this paper,two new guidance laws based on differential game theory are proposed and investigated for the attacker in an attacker-defender-target scenario.The conditions for the attacker winning the game are analyzed when the target and defender using the differential game guidance law based on the linear model.The core ideas underlying the two guidance laws are the attacker evading to a critical safe boundary from the defender,and then maintaining a critical miss distance.The guidance law more appropriate for the attacker to win the game differs according to the initial parameters.Unlike other guidance laws,when using the derived guidance laws there is no need to know the target and the defender’s control efforts.The results of numerical simulations show that the attacker can evade the defender and hit the target successfully by using the proposed derived guidance laws.展开更多
To improve the surface integrity and high cycle fatigue property of Ti6Al4V ELI alloy,the electric pulse has been introduced into the ultrasonic surface rolling process(USRP),which is called electric pulse-assisted ul...To improve the surface integrity and high cycle fatigue property of Ti6Al4V ELI alloy,the electric pulse has been introduced into the ultrasonic surface rolling process(USRP),which is called electric pulse-assisted ultrasonic surface rolling process(EUSRP).With the help of“electroplasticity”of the electric pulse,the thickness of the surface gradient deformation layer was about three times of the USRP specimens by adjusting the pulse current level.However,the surface hardness decreases due to the continuous effect of the pulse current and the“skin effect”during treatment.It is worth noting that the higher the applied pulse current,the more severe the softening.This paradox causes the fatigue performance of EUSRP specimens lower than that of USRP specimens.To break this paradox,the EUSRP treatment is followed by a USRP treatment.The EUSRP-2(with a pulse current of 200 A)+USRP specimens exhibit excellent surface hardness,a gradient deformation layer thickness of about 400μm,low surface roughness and high compressive residual compressive stress.Besides,the hardening mechanisms of the different surface strengthening specimens have been quantitatively analyzed in combination with microstructure analysis.The fatigue life of Ti6Al4V ELI alloy can be improved by about 25 times at 780 MPa using the EUSRP-2+USRP treatment,the main reason for the highest fatigue life is the deepest surface gradient layer and the deepest crack initiation site.The fatigue limit of the EUSRP-2+USRP specimens is not the highest because too much surface hardening causes compressive residual stress relaxation during cycling and the beneficial effect of compressive residual stress is eliminated.展开更多
This study aims to investigate the protective effects of BlingLife®-berry extract on the eyes.BlingLife®-berry extract is a mixture of high-quality natural berries,including blackcurrant,aromia,bilberry and ...This study aims to investigate the protective effects of BlingLife®-berry extract on the eyes.BlingLife®-berry extract is a mixture of high-quality natural berries,including blackcurrant,aromia,bilberry and maquiberry.The main active ingredient responsible for theeye-protective effects is anthocyanins.Anthocyanins are natural water-soluble pigments belonging to the flavonoid class,and theyhave multiple benefits,including improving vision,anti-inflammatory and antibacterial properties,and antioxidant effects.Dueto the dual benefits of anthocyanins in protecting vision and eliminating free radicals,this study explores the comprehensive eye protective effects of BlingLife®-berry extract in terms of combating blue light-induced eye damage and oxidative stress-inducedvisual fatigue.The results provide robust evidence for the in vivo effects and further technological applications of BlingLife®-berry extract.展开更多
Singular spectrum analysis is widely used in geodetic time series analysis.However,when extracting time-varying periodic signals from a large number of Global Navigation Satellite System(GNSS)time series,the selection...Singular spectrum analysis is widely used in geodetic time series analysis.However,when extracting time-varying periodic signals from a large number of Global Navigation Satellite System(GNSS)time series,the selection of appropriate embedding window size and principal components makes this method cumbersome and inefficient.To improve the efficiency and accuracy of singular spectrum analysis,this paper proposes an adaptive singular spectrum analysis method by combining spectrum analysis with a new trace matrix.The running time and correlation analysis indicate that the proposed method can adaptively set the embedding window size to extract the time-varying periodic signals from GNSS time series,and the extraction efficiency of a single time series is six times that of singular spectrum analysis.The method is also accurate and more suitable for time-varying periodic signal analysis of global GNSS sites.展开更多
For the system of water samples collected from Yangtze River,the effects of seasonal variation and Fe（III） concentrations on the formation and distribution of trihalomethanes （THMs） during chlorination have been i...For the system of water samples collected from Yangtze River,the effects of seasonal variation and Fe（III） concentrations on the formation and distribution of trihalomethanes （THMs） during chlorination have been investigated.The corresponding lifetime cancer risk of the formed THMs to human beings was estimated using the parameters and procedure issued by the US EPA.The results indicated that the average concentration of THMs （100.81 μg/L） in spring was significantly higher than that in other seasons,which was related to the higher bromide ion concentration resulted from the intrusion of tidal saltwater.The total cancer risk in spring reached 8.23 × 10 ？5 and 8.86 × 10 ？5 for males and females,respectively,which were about two times of those in summer under the experimental conditions.Furthermore,it was found that the presence of Fe（III） resulted in the increased level of THMs and greater cancer risk from exposure to humans.Under weak basic conditions,about 10% of the increment of THMs from the water samples in spring was found in the presence of 0.5 mg/L Fe（III） compared with the situation without Fe（III）.More attention should be given to the effect of the coexistence of Fe（III） and bromide ions on the risk assessment of human intake of THMs from drinking water should be paid more attention,especially in the coastland and estuaries.展开更多
Tumor microenvironment(TME)-activatable probes have been proven to effectively increase signal-tobackground ratios(SBRs)and improve the success rate of complete tumor resection.However,many fluorescence probes have to...Tumor microenvironment(TME)-activatable probes have been proven to effectively increase signal-tobackground ratios(SBRs)and improve the success rate of complete tumor resection.However,many fluorescence probes have to be loaded into a nanocarrier for tumor targeted delivery,which consequently encounters poor drug loading,heterogeneous composition and non-encapsulated drug aggregates occurred during nanoformulation fabrications.Herein,a nitroreductase(NTR)-activated“OFF-ON”near-infrared fluorescence nanoprobe,named Nano Bodipy,was synthesized by the spontaneous self-assembling of NTRresponsive dye-polyethylene glycol(PEG)amphiphilic polymer in water.The NTR-responsive dye acted as the hydrophobic segment in the amphiphilic polymer,yielding a homogeneous composition and a high loading of 12.2 wt%(according to calculation)in the synthesized Nano Bodipy.The synthesized Nano Bodipy can efficiently accumulate in tumors via the enhanced permeability and retention(EPR)effect,enabling non-invasive tumor-targeted fluorescence imaging and guiding complete tumor resection.Once the synthesized Nano Bodipy entered the tumor cells,they dissociated and were activated by overexpressed NTR.With the real-time fluorescence guide of Nano Bodipy,complete tumor resection surgery was performed successfully.展开更多
Atomic force microscopy (AFM) was employed to quantitatively detect the interaction between a transcription factor, ZmDREBIA, and its target DNA sequence (DRE).The specificity of the interaction was revealed by compar...Atomic force microscopy (AFM) was employed to quantitatively detect the interaction between a transcription factor, ZmDREBIA, and its target DNA sequence (DRE).The specificity of the interaction was revealed by comparing the binding probability of ZmDREBIA to DRE element with core sequence ACCGAC and to the ERE element with core sequence AGCCGCC. Moreover, the single-molecular unbinding force between ZmDREBIA and DRE element was determined using Poisson statistical method to be 99±9 pN.The results indicated that AFM could serve as a sensitive and reliable technique to probe the interaction properties of the transcription factor and DNA element at single-molecular level, thus indicating that AFM is advantageous over the traditional methods, such as the electrophoretic mobility shift assay, regarding to the functional analysis of transcription factors.展开更多
Cellular immunity mediated by CD8+T cells plays an indispensable role in bacterial and viral clearance and cancers.However,persistent antigen stimulation of CD8+T cells leads to an exhausted or dysfunctional cellular ...Cellular immunity mediated by CD8+T cells plays an indispensable role in bacterial and viral clearance and cancers.However,persistent antigen stimulation of CD8+T cells leads to an exhausted or dysfunctional cellular state characterized by the loss of effector function and high expression of inhibitory receptors during chronic viral infection and in tumors.Numerous studies have shown that glycogen synthase kinase 3(GSK3)controls the function and development of immune cells,but whether GSK3 affects CD8+T cells is not clearly elucidated.Here,we demonstrate that mice with deletion of Gsk3αand Gsk3βin activated CD8+T cells(DKO)exhibited decreased CTL differentiation and effector function during acute and chronic viral infection.In addition,DKO mice failed to control tumor growth due to the upregulated expression of inhibitory receptors and augmented T-cell exhaustion in tumor-infiltrating CD8+T cells.Strikingly,anti-PD-1 immunotherapy substantially restored tumor rejection in DKO mice.Mechanistically,GSK3 regulates T-cell exhaustion by suppressing TCR-induced nuclear import of NFAT,thereby in turn dampening NFAT-mediated exhaustion-related gene expression,including TOX/TOX2 and PD-1.Thus,we uncovered the molecular mechanisms underlying GSK3 regulation of CTL differentiation and T-cell exhaustion in anti-tumor immune responses.展开更多
Proanthocyanidins(PAs) are specialized metabolites that infuence persimmon fruit quality.Normal astringent(A)-type and non-astringent(NA)-type mutants show significant variation in PA accumulation, but the infuencing ...Proanthocyanidins(PAs) are specialized metabolites that infuence persimmon fruit quality.Normal astringent(A)-type and non-astringent(NA)-type mutants show significant variation in PA accumulation, but the infuencing mechanism remains unclear. In this study, among the six identified DTXs/MATEs proteins associated with PA accumulation, we observed that allelic variation and preferential transport by Dk DTX5/MATE5 induced variation in PA accumulation for A-type and NA-type fruit. The expression pattern of Dk DTX5/MATE5 was correlated with PA accumulation in NA-type fruit. Upregulation and downregulation of Dk DTX5/MATE5 promoted and inhibited PA accumulation, respectively, in the NA-type fruit. Interestingly, transporter assays of Xenopus laevis oocytes indicated that Dk DTX5/MATE5 preferentially transported the PA precursors catechin, epicatechin, and epicatechin gallate, resulting in their increased ratios relative to the total PAs, which was the main source of variation in PA accumulation between the A-type and NA-type. The allele lacking Ser-84 in Dk DTX5/MATE5 was identified as a dominantly expressed gene in the A-type and lost its transport function. Site-directed mutagenesis revealed that Dk DTX5/MATE5 binds to PA precursors via Ser-84. These findings clarify the association between the transporter function of Dk DTX5/MATE5 and PA variation, and can contribute to the breeding of new cultivars with improved fruit quality.展开更多
Driven by the serious ecological problems,it is urgent to explore high-efficiency sustainable energy technologies.Oxygen electrocatalysis acts as important half-reactions in the emerging electrochemical energy techniq...Driven by the serious ecological problems,it is urgent to explore high-efficiency sustainable energy technologies.Oxygen electrocatalysis acts as important half-reactions in the emerging electrochemical energy techniques including electrolysis and batteries.Gel composites exhibit the merits of rich porous,superior hydrophilic,and large specific surface area,which can significantly improve the electrolyte penetration and boost the kinetics process of oxygen electrocatalysis.In this invited contribution,the advances and challenges of a novel gel materials for oxygen electrocatalysis are summarized.Starting from the structure-activity-performance relationship of gel materials,synthetic routes of nanostructured gel materials,namely,radical polymerization,sol-gel method,hydrothermal/solvothermal reactions,and ligand-substitution method,are introduced.Afterward,the gel composites are divided into polymer-based,metal-based,and carbon-based materials in turn,and their applications in oxygen electrocatalysis are discussed respectively.At the end,the perspective and challenges for advanced gel oxygen electrocatalysts are proposed.展开更多
Rye(Secale cereale)is an important crop with multiple uses and a valuable genetic resource for wheat breeding.However,due to its complex genome and outcrossing nature,the origin of cultivated rye remains elusive.The g...Rye(Secale cereale)is an important crop with multiple uses and a valuable genetic resource for wheat breeding.However,due to its complex genome and outcrossing nature,the origin of cultivated rye remains elusive.The geneticist N.I.Vavilov proposed that cultivated rye had been domesticated from weedy rye,rather than directly from wild species like other crops.Unraveling the domestication history of rye will extend our understanding of crop evolution and upend our inherent understanding of agricultural weeds.To this end,in this study we generated the 8.5 Tb of whole-genome resequencing data from 116 worldwide accessions of wild,weedy,and cultivated rye,and demonstrated that cultivated rye was domesticated directly from weedy relatives with a similar but enhanced genomic selection by humans.We found that a repertoire of genes that experienced artificial selection is associated with important agronomic traits,including shattering,grain yield,and disease resistance.Furthermore,we identified a composite introgression in cultivated rye from the wild perennial Secale strictum and detected a 2-Mb introgressed fragment containing a candidate ammonium transporter gene with potential effect on the grain yield and plant growth of rye.Taken together,our findings unravel the domestication history of cultivated rye,suggest that interspecific introgression serves as one of the likely causes of obscure species taxonomy of the genus Secale,and provide an important resource for future rye and wheat breeding.展开更多
This paper is concerned with a mutualism ecological model with stochastic perturba- tions. The local existence and uniqueness of a positive solution are obtained with positive initial value, and the asymptotic behavio...This paper is concerned with a mutualism ecological model with stochastic perturba- tions. The local existence and uniqueness of a positive solution are obtained with positive initial value, and the asymptotic behavior to the problem is studied. Moreover, we show that the solution is stochastically bounded, uniformly continuous and stochastic perma- nence. The sufficient conditions for the system to be extinct are given and the conditionsfor the system to be persistent are also established. At last, some figures are presented to illustrate our main results.展开更多
This article presents a novel and flexible bubble modelling technique for multi-fluid simulations using a volume fraction representation. By combining the volume fraction data obtained from a primary multi-fluid simul...This article presents a novel and flexible bubble modelling technique for multi-fluid simulations using a volume fraction representation. By combining the volume fraction data obtained from a primary multi-fluid simulation with simple and efficient secondary bubble simulation, a range of real-world bubble phenomena are captured with a high degree of physical realism, including large bubble deformation,sub-cell bubble motion, bubble stacking over the liquid surface, bubble volume change, dissolving of bubbles,etc. Without any change in the primary multi-fluid simulator, our bubble modelling approach is applicable to any multi-fluid simulator based on the volume fraction representation.展开更多
The process of selectively introducing a CF_(3) group into an organic molecule using inexpensive, stable, and solid sodium trifluoromethanesulfinate has rapidly advanced in recent years to become an eco-friendly metho...The process of selectively introducing a CF_(3) group into an organic molecule using inexpensive, stable, and solid sodium trifluoromethanesulfinate has rapidly advanced in recent years to become an eco-friendly method used by organic chemists to synthesize various natural and bioactive molecules. This review focuses on advances made within the last five years regarding C-H functionalisation, namely thermochemical C(sp^(2))-H (thio)trifluoromethylations, photochemical C(sp^(2))-H trifluoromethylations, and electrochemical C(sp^(2))-H trifluoromethylations, using Langlois’ reagent (NaSO_(2)CF_(3)).展开更多
基金supported by the National Natural Science Foundation of China(22075092)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(B21003).
文摘Zinc–air batteries(ZABs)are expected to be some of the most promising power sources for wearable and portable electronic devices and have received widespread research interest.As an ion conductor connecting anodes and cathodes,the electrolyte is critical for the overall performance of ZABs(e.g.,energy density,rechargeability,and operating voltage).Compared with liquid electrolytes,polymer-based electrolytes have superior characteristics for ZABs,such as negligible electrolyte leakage,three-phase interface stabilization,and dendrite suppression.In this perspective,we focus on recent progress in polymer-based electrolytes for ZABs.After a brief introduction to ZABs and electrolytes,we emphasize the development of polymer-based electrolytes in terms of their intrinsic properties and interfacial chemistry.Finally,challenges and viable strategies are proposed for polymer-based electrolytes in ZABs.We hope that this work will provide useful guidance to spur the development of high-performance ZABs based on advanced polymer-based electrolytes.
文摘Fuel cells have attracted extensive attention due to their high conversion efficiency and environmental friendliness.However,their wider application is limited by the poor activity and high cost of platinum(Pt),which is widely used as the cathode catalyst to overcome the slow kinetics associated with oxygen reduction reaction(ORR).Pt‐based composites with one‐dimensional(1D)nanoarchitectures demonstrate great advantages towards efficient ORR catalysis.This review focuses on the recent advancements in the design and synthesis of 1D Pt‐based ORR catalysts.After introducing the fundamental ORR mechanism and the advanced 1D architectures,their synthesis strategies(template‐based and template‐free methods)are discoursed.Subsequently,their morphology and structure optimization are highlighted,followed by the superstructure assembly using 1D Pt‐based blocks.Finally,the challenges and perspectives on the synthesis innovation,structure design,physical characterization,and theoretical investigations are proposed for 1D Pt‐based ORR nanocatalysts.We anticipate this study will inspire more research endeavors on efficient ORR nanocatalysts in fuel cell application.
基金This work is supported by the National Natural Science Foundation of China(22075092)the Program for HUST Academic Frontier Youth Team(2018QYTD15).
文摘Oxygen electrocatalysts are of great importance for the air electrode in zinc-air batteries(ZABs).Owing to the high specific surface area,controllable pore size and unsaturated metal active sites,metal-organic frameworks(MOFs)derivatives have been widely studied as oxygen electrocatalysts in ZABs.To date,many strategies have been developed to generate efficient oxygen electrocatalysts from MOFs for improving the performance of ZABs.In this review,the latest progress of the MOF-derived non-noble metal-oxygen electrocatalysts in ZABs is reviewed.The performance of these MOF-derived catalysts toward oxygen reduction,and oxygen evolution reactions is discussed based on the categories of metal-free carbon materials,single-atom catalysts,metal cluster/carbon composites and metal compound/carbon composites.Moreover,we provide a comprehensive overview on the design strategies of various MOF-derived non-noble metal-oxygen electrocatalysts and their structure-performance relationship.Finally,the challenges and perspectives are provided for further advancing the MOF-derived oxygen electrocatalysts in ZABs.
基金supported by the National Natural Science Foundation of China(Grant No.10872108,10876100)the Program for New Century Excellent Talents in University(Grant No. NCET-07-0477)+1 种基金the National Basic Research Program of China(Grant No. 2010CB832701)ASFC
文摘The sensitivity problem to mesh distortion and the low accuracy problem of the stress solutions are two inherent difficulties in the finite element method.By applying the fundamental analytical solutions (in global Cartesian coordinates) to the Airy stress function of the anisotropic materials,8-and 12-node plane quadrilateral hybrid stress-function (HS-F) elements are successfully developed based on the principle of the minimum complementary energy.Numerical results show that the present new elements exhibit much better and more robust performance in both displacement and stress solutions than those obtained from other models.They can still perform very well even when the element shapes degenerate into a triangle and a concave quadrangle.It is also demonstrated that the proposed construction procedure is an effective way for developing shape-free finite element models which can completely overcome the sensitivity problem to mesh distortion and can produce highly accurate stress solutions.
基金supported by the National Natural Science Foundation of China(81872810,81673374 and 81871473)Wuhan University of Science and Technology Plan for Applied Fundamental Research(2017060201010146,China)the Fundamental Research Funds for the Central Universities(2018KFYYXJJ019,2019KFYRCPY049 and 2016YXMS138,China).
文摘Blocking the programmed death-ligand 1(PD-L1)on tumor cells with monoclonal antibody therapy has emerged as powerful weapon in cancer immunotherapy.However,only a minority of patients presented immune responses in clinical trials.To develop an alternative treatment method based on immune checkpoint blockade,we designed a novel and efficient CRISPR-Cas9 genome editing system delivered by cationic copolymer aPBAE to downregulate PD-L1 expression on tumor cells via specifically knocking out Cyclin-dependent kinase 5(Cdk5)gene in vivo.The expression of PD-L1 on tumor cells was significantly attenuated by knocking out Cdk5,leading to effective tumor growth inhibition in murine melanoma and lung metastasis suppression in triple-negative breast cancer.Importantly,we demonstrated that aPBAE/Cas9-Cdk5 treatment elicited strong T cell-mediated immune responses in tumor microenvironment that the population of CD8^+T cells was significantly increased while regulatory T cells(Tregs)was decreased.It may be the first case to exhibit direct in vivo PD-L1 downregulation via CRISPR-Cas9 genome editing technology for cancer therapy.It will provide promising strategy for preclinical antitumor treatment through the combination of nanotechnology and genome engineering.
基金co-supported by the National Natural Science Foundation of China(No.11672093)the Shanghai Aerospace Science and Technology Innovation Foundation,China(No.SAST2016039)
文摘In this paper,two new guidance laws based on differential game theory are proposed and investigated for the attacker in an attacker-defender-target scenario.The conditions for the attacker winning the game are analyzed when the target and defender using the differential game guidance law based on the linear model.The core ideas underlying the two guidance laws are the attacker evading to a critical safe boundary from the defender,and then maintaining a critical miss distance.The guidance law more appropriate for the attacker to win the game differs according to the initial parameters.Unlike other guidance laws,when using the derived guidance laws there is no need to know the target and the defender’s control efforts.The results of numerical simulations show that the attacker can evade the defender and hit the target successfully by using the proposed derived guidance laws.
基金supported by the Natural Science Foundation of Guangdong,China(No.2022A1515010023)Zhuhai Industrial Core Research Project(No.2220004002348).
文摘To improve the surface integrity and high cycle fatigue property of Ti6Al4V ELI alloy,the electric pulse has been introduced into the ultrasonic surface rolling process(USRP),which is called electric pulse-assisted ultrasonic surface rolling process(EUSRP).With the help of“electroplasticity”of the electric pulse,the thickness of the surface gradient deformation layer was about three times of the USRP specimens by adjusting the pulse current level.However,the surface hardness decreases due to the continuous effect of the pulse current and the“skin effect”during treatment.It is worth noting that the higher the applied pulse current,the more severe the softening.This paradox causes the fatigue performance of EUSRP specimens lower than that of USRP specimens.To break this paradox,the EUSRP treatment is followed by a USRP treatment.The EUSRP-2(with a pulse current of 200 A)+USRP specimens exhibit excellent surface hardness,a gradient deformation layer thickness of about 400μm,low surface roughness and high compressive residual compressive stress.Besides,the hardening mechanisms of the different surface strengthening specimens have been quantitatively analyzed in combination with microstructure analysis.The fatigue life of Ti6Al4V ELI alloy can be improved by about 25 times at 780 MPa using the EUSRP-2+USRP treatment,the main reason for the highest fatigue life is the deepest surface gradient layer and the deepest crack initiation site.The fatigue limit of the EUSRP-2+USRP specimens is not the highest because too much surface hardening causes compressive residual stress relaxation during cycling and the beneficial effect of compressive residual stress is eliminated.
文摘This study aims to investigate the protective effects of BlingLife®-berry extract on the eyes.BlingLife®-berry extract is a mixture of high-quality natural berries,including blackcurrant,aromia,bilberry and maquiberry.The main active ingredient responsible for theeye-protective effects is anthocyanins.Anthocyanins are natural water-soluble pigments belonging to the flavonoid class,and theyhave multiple benefits,including improving vision,anti-inflammatory and antibacterial properties,and antioxidant effects.Dueto the dual benefits of anthocyanins in protecting vision and eliminating free radicals,this study explores the comprehensive eye protective effects of BlingLife®-berry extract in terms of combating blue light-induced eye damage and oxidative stress-inducedvisual fatigue.The results provide robust evidence for the in vivo effects and further technological applications of BlingLife®-berry extract.
基金supported by the National Natural Science Foundation of China(Grants:42204006,42274053,42030105,and 41504031)the Open Research Fund Program of the Key Laboratory of Geospace Environment and Geodesy,Ministry of Education,China(Grants:20-01-03 and 21-01-04)。
文摘Singular spectrum analysis is widely used in geodetic time series analysis.However,when extracting time-varying periodic signals from a large number of Global Navigation Satellite System(GNSS)time series,the selection of appropriate embedding window size and principal components makes this method cumbersome and inefficient.To improve the efficiency and accuracy of singular spectrum analysis,this paper proposes an adaptive singular spectrum analysis method by combining spectrum analysis with a new trace matrix.The running time and correlation analysis indicate that the proposed method can adaptively set the embedding window size to extract the time-varying periodic signals from GNSS time series,and the extraction efficiency of a single time series is six times that of singular spectrum analysis.The method is also accurate and more suitable for time-varying periodic signal analysis of global GNSS sites.
基金financially supported by National Mega-Project of Science and Technology of China (No.2008ZX07421-002)the National Eleventh Five-Year Pillar Program of Science and Technology of China (No.2006BAJ04A07)
文摘For the system of water samples collected from Yangtze River,the effects of seasonal variation and Fe（III） concentrations on the formation and distribution of trihalomethanes （THMs） during chlorination have been investigated.The corresponding lifetime cancer risk of the formed THMs to human beings was estimated using the parameters and procedure issued by the US EPA.The results indicated that the average concentration of THMs （100.81 μg/L） in spring was significantly higher than that in other seasons,which was related to the higher bromide ion concentration resulted from the intrusion of tidal saltwater.The total cancer risk in spring reached 8.23 × 10 ？5 and 8.86 × 10 ？5 for males and females,respectively,which were about two times of those in summer under the experimental conditions.Furthermore,it was found that the presence of Fe（III） resulted in the increased level of THMs and greater cancer risk from exposure to humans.Under weak basic conditions,about 10% of the increment of THMs from the water samples in spring was found in the presence of 0.5 mg/L Fe（III） compared with the situation without Fe（III）.More attention should be given to the effect of the coexistence of Fe（III） and bromide ions on the risk assessment of human intake of THMs from drinking water should be paid more attention,especially in the coastland and estuaries.
基金supported by the National Natural Science Foundation of China(Nos.51903201,82172798)the Natural Science Foundation of Shaanxi Province(No.2023-YBSF-270)+1 种基金the Open Program of NHC Key Laboratory of Nuclear Medicine and Jiangsu Key Laboratory of Molecular Nuclear Medicine(No.KF202203)Horizontal Project of the First Affiliated Hospital of Xi'an Jiaotong University(No.202304174)。
文摘Tumor microenvironment(TME)-activatable probes have been proven to effectively increase signal-tobackground ratios(SBRs)and improve the success rate of complete tumor resection.However,many fluorescence probes have to be loaded into a nanocarrier for tumor targeted delivery,which consequently encounters poor drug loading,heterogeneous composition and non-encapsulated drug aggregates occurred during nanoformulation fabrications.Herein,a nitroreductase(NTR)-activated“OFF-ON”near-infrared fluorescence nanoprobe,named Nano Bodipy,was synthesized by the spontaneous self-assembling of NTRresponsive dye-polyethylene glycol(PEG)amphiphilic polymer in water.The NTR-responsive dye acted as the hydrophobic segment in the amphiphilic polymer,yielding a homogeneous composition and a high loading of 12.2 wt%(according to calculation)in the synthesized Nano Bodipy.The synthesized Nano Bodipy can efficiently accumulate in tumors via the enhanced permeability and retention(EPR)effect,enabling non-invasive tumor-targeted fluorescence imaging and guiding complete tumor resection.Once the synthesized Nano Bodipy entered the tumor cells,they dissociated and were activated by overexpressed NTR.With the real-time fluorescence guide of Nano Bodipy,complete tumor resection surgery was performed successfully.
文摘Atomic force microscopy (AFM) was employed to quantitatively detect the interaction between a transcription factor, ZmDREBIA, and its target DNA sequence (DRE).The specificity of the interaction was revealed by comparing the binding probability of ZmDREBIA to DRE element with core sequence ACCGAC and to the ERE element with core sequence AGCCGCC. Moreover, the single-molecular unbinding force between ZmDREBIA and DRE element was determined using Poisson statistical method to be 99±9 pN.The results indicated that AFM could serve as a sensitive and reliable technique to probe the interaction properties of the transcription factor and DNA element at single-molecular level, thus indicating that AFM is advantageous over the traditional methods, such as the electrophoretic mobility shift assay, regarding to the functional analysis of transcription factors.
基金supported by the National Natural Science Foundation of China(31770953,81830047,and 81961138008 to CX and 32070877 to W-HL),1000 Young Talents Program of China(NX)the Fundamental Research Funds for the Central Universities of China-Xiamen University(20720170064 to CX).
文摘Cellular immunity mediated by CD8+T cells plays an indispensable role in bacterial and viral clearance and cancers.However,persistent antigen stimulation of CD8+T cells leads to an exhausted or dysfunctional cellular state characterized by the loss of effector function and high expression of inhibitory receptors during chronic viral infection and in tumors.Numerous studies have shown that glycogen synthase kinase 3(GSK3)controls the function and development of immune cells,but whether GSK3 affects CD8+T cells is not clearly elucidated.Here,we demonstrate that mice with deletion of Gsk3αand Gsk3βin activated CD8+T cells(DKO)exhibited decreased CTL differentiation and effector function during acute and chronic viral infection.In addition,DKO mice failed to control tumor growth due to the upregulated expression of inhibitory receptors and augmented T-cell exhaustion in tumor-infiltrating CD8+T cells.Strikingly,anti-PD-1 immunotherapy substantially restored tumor rejection in DKO mice.Mechanistically,GSK3 regulates T-cell exhaustion by suppressing TCR-induced nuclear import of NFAT,thereby in turn dampening NFAT-mediated exhaustion-related gene expression,including TOX/TOX2 and PD-1.Thus,we uncovered the molecular mechanisms underlying GSK3 regulation of CTL differentiation and T-cell exhaustion in anti-tumor immune responses.
基金supported by the National Key R&D Program of China (2019YFD1000600)。
文摘Proanthocyanidins(PAs) are specialized metabolites that infuence persimmon fruit quality.Normal astringent(A)-type and non-astringent(NA)-type mutants show significant variation in PA accumulation, but the infuencing mechanism remains unclear. In this study, among the six identified DTXs/MATEs proteins associated with PA accumulation, we observed that allelic variation and preferential transport by Dk DTX5/MATE5 induced variation in PA accumulation for A-type and NA-type fruit. The expression pattern of Dk DTX5/MATE5 was correlated with PA accumulation in NA-type fruit. Upregulation and downregulation of Dk DTX5/MATE5 promoted and inhibited PA accumulation, respectively, in the NA-type fruit. Interestingly, transporter assays of Xenopus laevis oocytes indicated that Dk DTX5/MATE5 preferentially transported the PA precursors catechin, epicatechin, and epicatechin gallate, resulting in their increased ratios relative to the total PAs, which was the main source of variation in PA accumulation between the A-type and NA-type. The allele lacking Ser-84 in Dk DTX5/MATE5 was identified as a dominantly expressed gene in the A-type and lost its transport function. Site-directed mutagenesis revealed that Dk DTX5/MATE5 binds to PA precursors via Ser-84. These findings clarify the association between the transporter function of Dk DTX5/MATE5 and PA variation, and can contribute to the breeding of new cultivars with improved fruit quality.
基金financially supported by the National Natural Science Foundation of China(No.22102125)The Scientific Research Foundation of Wuhan Institute of Technology(No.K2021040)the Innovation Foundation of Key Laboratory of Green Chemical Engineering Process of Ministry of Education(No.GCX202108)are also acknowledged.
文摘Driven by the serious ecological problems,it is urgent to explore high-efficiency sustainable energy technologies.Oxygen electrocatalysis acts as important half-reactions in the emerging electrochemical energy techniques including electrolysis and batteries.Gel composites exhibit the merits of rich porous,superior hydrophilic,and large specific surface area,which can significantly improve the electrolyte penetration and boost the kinetics process of oxygen electrocatalysis.In this invited contribution,the advances and challenges of a novel gel materials for oxygen electrocatalysis are summarized.Starting from the structure-activity-performance relationship of gel materials,synthetic routes of nanostructured gel materials,namely,radical polymerization,sol-gel method,hydrothermal/solvothermal reactions,and ligand-substitution method,are introduced.Afterward,the gel composites are divided into polymer-based,metal-based,and carbon-based materials in turn,and their applications in oxygen electrocatalysis are discussed respectively.At the end,the perspective and challenges for advanced gel oxygen electrocatalysts are proposed.
基金This work was supported by the National Natural Science Foundation(grant 9143511)Department of Science and Technology of Zhejiang Province(grant 2020C02002)+1 种基金the Zhejiang Natural Science Foundation(grant LZ17C130001)the Jiangsu Collaborative Innovation Center for Modern Crop Production,and the 111 Project(grant B17039)to L.F.
文摘Rye(Secale cereale)is an important crop with multiple uses and a valuable genetic resource for wheat breeding.However,due to its complex genome and outcrossing nature,the origin of cultivated rye remains elusive.The geneticist N.I.Vavilov proposed that cultivated rye had been domesticated from weedy rye,rather than directly from wild species like other crops.Unraveling the domestication history of rye will extend our understanding of crop evolution and upend our inherent understanding of agricultural weeds.To this end,in this study we generated the 8.5 Tb of whole-genome resequencing data from 116 worldwide accessions of wild,weedy,and cultivated rye,and demonstrated that cultivated rye was domesticated directly from weedy relatives with a similar but enhanced genomic selection by humans.We found that a repertoire of genes that experienced artificial selection is associated with important agronomic traits,including shattering,grain yield,and disease resistance.Furthermore,we identified a composite introgression in cultivated rye from the wild perennial Secale strictum and detected a 2-Mb introgressed fragment containing a candidate ammonium transporter gene with potential effect on the grain yield and plant growth of rye.Taken together,our findings unravel the domestication history of cultivated rye,suggest that interspecific introgression serves as one of the likely causes of obscure species taxonomy of the genus Secale,and provide an important resource for future rye and wheat breeding.
文摘This paper is concerned with a mutualism ecological model with stochastic perturba- tions. The local existence and uniqueness of a positive solution are obtained with positive initial value, and the asymptotic behavior to the problem is studied. Moreover, we show that the solution is stochastically bounded, uniformly continuous and stochastic perma- nence. The sufficient conditions for the system to be extinct are given and the conditionsfor the system to be persistent are also established. At last, some figures are presented to illustrate our main results.
基金supported by the National High Technology Research and Development Program of China (No. 2013AA013903)the National Natural Science Foundation of China (No. 61120106007)+3 种基金Research Grant of Beijing Higher Institution Engineering Research CenterTsinghua University Initiative Scientific Research Programsupported in part by the U.S. National Science Foundationthe University of North Carolina Arts & Sciences Foundation
文摘This article presents a novel and flexible bubble modelling technique for multi-fluid simulations using a volume fraction representation. By combining the volume fraction data obtained from a primary multi-fluid simulation with simple and efficient secondary bubble simulation, a range of real-world bubble phenomena are captured with a high degree of physical realism, including large bubble deformation,sub-cell bubble motion, bubble stacking over the liquid surface, bubble volume change, dissolving of bubbles,etc. Without any change in the primary multi-fluid simulator, our bubble modelling approach is applicable to any multi-fluid simulator based on the volume fraction representation.
基金Natural Science Foundation of Zhejiang Province(No. LY21B060009) for financial support。
文摘The process of selectively introducing a CF_(3) group into an organic molecule using inexpensive, stable, and solid sodium trifluoromethanesulfinate has rapidly advanced in recent years to become an eco-friendly method used by organic chemists to synthesize various natural and bioactive molecules. This review focuses on advances made within the last five years regarding C-H functionalisation, namely thermochemical C(sp^(2))-H (thio)trifluoromethylations, photochemical C(sp^(2))-H trifluoromethylations, and electrochemical C(sp^(2))-H trifluoromethylations, using Langlois’ reagent (NaSO_(2)CF_(3)).
