With the development of the city and the increase of the population, the de<span style="font-family:Verdana;">mand for transportation is increasing. The increases in transportation ways </span>&l...With the development of the city and the increase of the population, the de<span style="font-family:Verdana;">mand for transportation is increasing. The increases in transportation ways </span><span style="font-family:Verdana;">and demand have also brought certain energy and environmental problems t</span><span style="font-family:Verdana;">o transportati</span><span style="font-family:Verdana;">on construction. A good transportation environment and green travel experience have an important role in promoting the happiness of urban lif</span><span style="font-family:Verdana;">e and the sustainable development of society. Based on this, the follo</span><span style="font-family:Verdana;">wing solutions are proposed for the construction and development of urban green </span><span style="font-family:Verdana;">transportation. First, as a guiding role, the government should formulate active transportation and green transportation policies to promote the reform of multiple p</span><span style="font-family:Verdana;">ublic transportation methods. Second, as a leading role, the market can support a variety of the construction of green travel modes, which could encourage the development of shared bicycles and new energy vehicles. Third, </span><span style="font-family:Verdana;">as the main role of city, the citizens would like to choose green travel tools wi</span><span style="font-family:Verdana;">th the guid</span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">ance</span></span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> in the conscious level. If we built green behavior into a fashionable business card of the city, green behavior will lead the city’s transportation construction and development.</span></span></span></span></span>展开更多
We designed an improved direct-current capacitor voltage balancing control model predictive control(MPC)for single-phase cascaded H-bridge multilevel photovoltaic(PV)inverters.Compared with conventional voltage balanc...We designed an improved direct-current capacitor voltage balancing control model predictive control(MPC)for single-phase cascaded H-bridge multilevel photovoltaic(PV)inverters.Compared with conventional voltage balanc-ing control methods,the method proposed could make the PV strings of each submodule operate at their maximum power point by independent capacitor voltage control.Besides,the predicted and reference value of the grid-connected current was obtained according to the maximum power output of the maximum power point tracking.A cost function was con-structed to achieve the high-precision grid-connected control of the CHB inverter.Finally,the effectiveness of the proposed control method was verified through a semi-physical simulation platform with three submodules.展开更多
Ripening of the model fruit tomato(Solanum lycopersicum)is controlled by a transcription factor network including NAC(NAM,ATAF1/2,and CUC2)domain proteins such as No-ripening(NOR),SlNAC1,and SlNAC4,but very little is ...Ripening of the model fruit tomato(Solanum lycopersicum)is controlled by a transcription factor network including NAC(NAM,ATAF1/2,and CUC2)domain proteins such as No-ripening(NOR),SlNAC1,and SlNAC4,but very little is known about the NAC targets or how they regulate ripening.Here,we conducted a systematic search of fruit-expressed NAC genes and showed that silencing NOR-like1(Solyc07g063420)using virus-induced gene silencing(VIGS)inhibited specific aspects of ripening.Ripening initiation was delayed by 14 days when NOR-like1 function was inactivated by CRISPR/Cas9 and fruits showed obviously reduced ethylene production,retarded softening and chlorophyll loss,and reduced lycopene accumulation.RNA-sequencing profiling and gene promoter analysis suggested that genes involved in ethylene biosynthesis(SlACS2,SlACS4),color formation(SlGgpps2,SlSGR1),and cell wall metabolism(SlPG2a,SlPL,SlCEL2,and SlEXP1)are direct targets of NOR-like1.Electrophoretic mobility shift assays(EMSA),chromatin immunoprecipitation-quantitative PCR(ChIP-qPCR),and dual-luciferase reporter assay(DLR)confirmed that NOR-like1 bound to the promoters of these genes both in vitro and in vivo,and activated their expression.Our findings demonstrate that NOR-like1 is a new positive regulator of tomato fruit ripening,with an important role in the transcriptional regulatory network.展开更多
Botrytis cinerea is a necrotrophic fungal pathogen that impacts a wide range of hosts, including Arabidopsis. Pretreatment with nitric oxide (NO) donor sodium nitroprusside (SNP) on Arabidopsis leaves suppressed Botry...Botrytis cinerea is a necrotrophic fungal pathogen that impacts a wide range of hosts, including Arabidopsis. Pretreatment with nitric oxide (NO) donor sodium nitroprusside (SNP) on Arabidopsis leaves suppressed Botrytis cinerea infection development. Additionally, in this study the dosage levels of SNP applied to the leaves had no direct, toxic impact on the development of the pathogen. The relationship between NO and reactive oxidant species (ROS) was studied by using both spectrophotometrical methods and staining leaf material with fluorescent dyes, nitro blue tetrazolium (NBT), and with 3,3-diaminobenzidine (DAB). The results showed that exogenous NO restrained the generation of ROS, especially H2O2, as the pathogen interacted with the Arabidopsis plant. And this inhibition of reactive oxidant burst coincided with delay infection development in NO-supplied leaves. The influence of elevated level of NO on antioxidant enzymes was investigated in this study. The activities of catalase (CAT) and guaiacol peroxidase (POD) were increased to different degrees in both: 1) SNP treated only leaves, and 2) SNP pretreated leaves that were subsequently inoculateted with pathogens. However, the activity of superoxide dismutase (SOD) was unchanged in the leaves studied. The decrease in H2O2 content probably resulted from the increase in activities of POD and CAT. Our study suggests that NO might trigger some metabolic reactions, i.e. enhanced enzyme activity that restrains H2O2 which ultimately results in resistance to B. cinerea infection.展开更多
To the Editor:Severe acute pancreatitis(SAP)is a common critical disease in gastroenterology,and 69.3%of patients have acute kidney injury(AKI).^([1])Early diagnosis and treatment are very important in improving the p...To the Editor:Severe acute pancreatitis(SAP)is a common critical disease in gastroenterology,and 69.3%of patients have acute kidney injury(AKI).^([1])Early diagnosis and treatment are very important in improving the prognosis of these patients.In recent years,machine learning models have been widely used in the medical field due to their excellent prediction performance.Some scholars have developed machine learning models that can solve the AKI prediction problem in specific populations and achieved good results.^([2])However,considering that the occurrence of AKI in patients with pancreatitis is also closely related to factors such as amylase and inflammatory markers,it is necessary to construct an AKI prediction model for the pancreatitis population.展开更多
The significance of early detection and isolation of infected individuals,along with the quantitative assessment of antibodies against the virus,has gained widespread recognition during the ongoing covid-19 pandemic.T...The significance of early detection and isolation of infected individuals,along with the quantitative assessment of antibodies against the virus,has gained widespread recognition during the ongoing covid-19 pandemic.This necessitates the development of cost-effective,user-friendly,decentralized testing methods characterized by both high sensitivity and specificity.In this article,we present a comprehensive review of an innovative,low-cost rapid decentralized immunoassay technology,applicable across various diagnostic and quantitative testing scenarios.Distinguishing itself from conventional immunoassay technologies,this method is featured with mechanically enhanced specificity without compromising sensitivity.We delve into the basic principle of the technology and a comparative analysis of this technology in relation to other immunodiagnostic methods,highlighting its potential applications in a wide spectrum of diagnostic tests.展开更多
As an apex predator the Amur tiger(Panthera tigris altaica)could play a pivotal role in maintaining the integrity of forest ecosystems in Northeast Asia.Due to habitat loss and harvest over the past century,tige...As an apex predator the Amur tiger(Panthera tigris altaica)could play a pivotal role in maintaining the integrity of forest ecosystems in Northeast Asia.Due to habitat loss and harvest over the past century,tigers rapidly declined in China and are now restricted to the Russian Far East and bordering habitat in nearby China.To facilitate restoration of the tiger in its historical range,reliable estimates of population size are essential to assess effectiveness of conservation interventions.Here we used camera trap data collected in Hunchun National Nature Reserve from April to June 2013 and 2014 to estimate tiger density and abundance using both maximum likelihood and Bayesian spatially explicit capture-recapture(SECR)methods.A minimum of 8 individuals were detected in both sample periods and the documentation of marking behavior and reproduction suggests the presence of a resident population.Using Bayesian SECR modeling within the 11400 km2 state space,density estimates were 0.33 and 0.40 individuals/100 km^(2) in 2013 and 2014,respectively,corresponding to an estimated abundance of 38 and 45 animals for this transboundary Sino-Russian population.In a maximum likelihood framework,we estimated densities of 0.30 and 0.24 individuals/100 km^(2) corresponding to abundances of 34 and 27,in 2013 and 2014,respectively.These density estimates are comparable to other published estimates for resident Amur tiger populations in the Russian Far East.This study reveals promising signs of tiger recovery in Northeast China,and demonstrates the importance of connectivity between the Russian and Chinese populations for recovering tigers in Northeast China.展开更多
The treatment of diabetic chronic wounds remains a global challenge due to the up-regulated inflammation response,oxidant stress,and persistent infection during healing process.Developing wound dressing materials with...The treatment of diabetic chronic wounds remains a global challenge due to the up-regulated inflammation response,oxidant stress,and persistent infection during healing process.Developing wound dressing materials with ideal biocompatibility,adequate mechanical strength,considerable under-water adhesion,sufficient anti-inflammation,antioxidant,and antibacterial properties is on-demand for clinical applications.In this study,we developed a bioactive skin-mimicking hydrogel band-aid through the combination of tannic acid(TA)and imidazolidinyl urea reinforced polyurethane(PMI)(TAP hydrogel)and explored its potentials in various medical applications,including hemostasis,normal skin incision,full-thickness skin wounds,and bacterial-infection skin incision on diabetic mice.TA was loaded into PMI hydrogel network to enhance the mechanical properties of TAP hydrogels through multiple non-covalent interactions(break strength:0.28-0.64 MPa;elongation at break:650-930%),which could resist the local stress and maintain the structural integrity of wound dressings during applications.Moreover,owing to the promising moisture-resistant adhesiveness and organ hemostasis,outstanding anti-inflammation,antibacterial,and antioxidant properties,TAP hydrogels could efficiently promote the recovery of skin incision and defects on diabetic mice.To further simulate the practical situation and explore the potential in clinical application,we also verified the treatment efficiency of TAP hydrogel in S.aureus-infected skin incision model on diabetic mice.展开更多
Development of biocompatible hydrogel adhesives with robust tissue adhesion to realize instant hemorrhage control and injury sealing,especially for emergency rescue and tissue repair,is still challenging.Herein,we rep...Development of biocompatible hydrogel adhesives with robust tissue adhesion to realize instant hemorrhage control and injury sealing,especially for emergency rescue and tissue repair,is still challenging.Herein,we report a potent hydrogel adhesive by free radical polymerization of N-acryloyl aspartic acid(AASP)in a facile and straightforward way.Through delicate adjustment of steric hindrance,the synergistic effect between interface interactions and cohesion energy can be achieved in PAASP hydrogel verified by X-ray photoelectron spectroscopy(XPS)analysis and simulation calculation compared to poly(N-acryloyl glutamic acid)(PAGLU)and poly(N-acryloyl amidomalonic acid)(PAAMI)hydrogels.The adhesion strength of the PAASP hydrogel could reach 120 kPa to firmly seal the broken organs to withstand the external force with persistent stability under physiological conditions,and rapid hemostasis in different hemorrhage models on mice is achieved using PAASP hydrogel as physical barrier.Furthermore,the paper-based Fe^(3+)transfer printing method is applied to construct PAASP-based Janus hydrogel patch with both adhesive and non-adhesive surfaces,by which simultaneous wound healing and postoperative anti-adhesion can be realized in gastric perforation model on mice.This advanced hydrogel may show vast potential as bio-adhesives for emergency rescue and tissue/organ repair.展开更多
P-chirogenic compounds have been applied in different fields,especially in asymmetric catalysis as ligands and organocatalysts.However,broader applicability has been severely restricted by the lack of efficient synthe...P-chirogenic compounds have been applied in different fields,especially in asymmetric catalysis as ligands and organocatalysts.However,broader applicability has been severely restricted by the lack of efficient synthetic methods.Consequently,developing efficient methods to access these compounds is of high synthetic value.Herein,we report a convenient,efficient,and unprecedented pathway to construct valuable P-chirogenic compounds via chiral selenide-catalyzed enantioselective electrophilic aromatic halogenation.Using a new chiral bifunctional selenide as the catalyst,a variety of bis(2-hydroxyaryl)aryl phosphine oxides were efficiently converted to the corresponding chlorinated and brominated P-chirogenic compounds with good to excellent enantioselectivities.By slightly adjusting the catalyst and solvent,this method is also able to prepare chiral alkyl diaryl phosphine oxides and diaryl phosphinates.Furthermore,control experiments revealed the decomposition pathways of catalysts and the possible reasons why chiral selenide catalyst was more effective than chiral sulfide catalyst.The effect of hydrogen bonding was studied,and the reason why the chlorination took place on the various aromatic rings was elucidated when the substrates were switched from triaryl phosphine oxides to alkyl diaryl phosphine oxides and diaryl phosphinates.展开更多
By inserting an air cavity into a one-dimensional photonic crystal of LiF/GaSb, a tunable filter covering the whole visible range is proposed. Following consideration of the dispersion of the materials, through modula...By inserting an air cavity into a one-dimensional photonic crystal of LiF/GaSb, a tunable filter covering the whole visible range is proposed. Following consideration of the dispersion of the materials, through modulating the thickness of the air cavity, we demonstrate that a single resonant peak can shift from 416.1 to 667.3 nm in the band gap at normal incidence by means of the transfer matrix method. The research also shows that the transmittance of the channel can be maximized when the number of periodic Li F/Ga Sb layers on one side of the air defect layer is equal to that of the other side. When adding a period to both sides respectively, the full width at half maximum of the defect mode is reduced by one order of magnitude. This structure will provide a promising approach to fabricate practical tunable filters in the visible region with ultra-wide tuning range.展开更多
Chiral benzo-fused N-heterocycles are frequently found in natural and synthetic products.However,their synthesis usually suffers from different limitations such as difficulty in accessing appropriate starting material...Chiral benzo-fused N-heterocycles are frequently found in natural and synthetic products.However,their synthesis usually suffers from different limitations such as difficulty in accessing appropriate starting materials and unsatisfactory stereoselectivities.In this work,an unprecedented chiral sulfide-catalyzed enantioselective Friedel-Crafts-type electrophilic chlorination is shown to construct various 3,4-functionalized tetrahydroquinolines with excellent enantio-and diastereoselectivities from readily available aniline derivatives.Interestingly,employing N-allyl 1-naphthanilides as substrates,divergent reactions via chlorocarbocyclization and dearomatization occurred to afford two chiral polycyclic benzo-fused N-heterocycles.The system that we developed extends the scope of asymmetric chlorination to general substrateswithout the need of a N-H group,and significantly promotes the synthesis of enantioenriched benzo-fused N-heterocycles.展开更多
文摘With the development of the city and the increase of the population, the de<span style="font-family:Verdana;">mand for transportation is increasing. The increases in transportation ways </span><span style="font-family:Verdana;">and demand have also brought certain energy and environmental problems t</span><span style="font-family:Verdana;">o transportati</span><span style="font-family:Verdana;">on construction. A good transportation environment and green travel experience have an important role in promoting the happiness of urban lif</span><span style="font-family:Verdana;">e and the sustainable development of society. Based on this, the follo</span><span style="font-family:Verdana;">wing solutions are proposed for the construction and development of urban green </span><span style="font-family:Verdana;">transportation. First, as a guiding role, the government should formulate active transportation and green transportation policies to promote the reform of multiple p</span><span style="font-family:Verdana;">ublic transportation methods. Second, as a leading role, the market can support a variety of the construction of green travel modes, which could encourage the development of shared bicycles and new energy vehicles. Third, </span><span style="font-family:Verdana;">as the main role of city, the citizens would like to choose green travel tools wi</span><span style="font-family:Verdana;">th the guid</span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">ance</span></span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> in the conscious level. If we built green behavior into a fashionable business card of the city, green behavior will lead the city’s transportation construction and development.</span></span></span></span></span>
基金Research on Control Methods and Fault Tolerance of Multilevel Electronic Transformers for PV Access(Project number:042300034204)Research on Open-Circuit Fault Diagnosis and Seamless Fault-Tolerant Control of Multiple Devices in Modular Multilevel Digital Power Amplifiers(Project number:202203021212210)Research on Key Technologies and Demonstrations of Low-Voltage DC Power Electronic Converters Based on SiC Devices Access(Project number:202102060301012)。
文摘We designed an improved direct-current capacitor voltage balancing control model predictive control(MPC)for single-phase cascaded H-bridge multilevel photovoltaic(PV)inverters.Compared with conventional voltage balanc-ing control methods,the method proposed could make the PV strings of each submodule operate at their maximum power point by independent capacitor voltage control.Besides,the predicted and reference value of the grid-connected current was obtained according to the maximum power output of the maximum power point tracking.A cost function was con-structed to achieve the high-precision grid-connected control of the CHB inverter.Finally,the effectiveness of the proposed control method was verified through a semi-physical simulation platform with three submodules.
基金This work was supported by the National Natural Science Foundation of China(NSFC 31571898,31772029,31572173).
文摘Ripening of the model fruit tomato(Solanum lycopersicum)is controlled by a transcription factor network including NAC(NAM,ATAF1/2,and CUC2)domain proteins such as No-ripening(NOR),SlNAC1,and SlNAC4,but very little is known about the NAC targets or how they regulate ripening.Here,we conducted a systematic search of fruit-expressed NAC genes and showed that silencing NOR-like1(Solyc07g063420)using virus-induced gene silencing(VIGS)inhibited specific aspects of ripening.Ripening initiation was delayed by 14 days when NOR-like1 function was inactivated by CRISPR/Cas9 and fruits showed obviously reduced ethylene production,retarded softening and chlorophyll loss,and reduced lycopene accumulation.RNA-sequencing profiling and gene promoter analysis suggested that genes involved in ethylene biosynthesis(SlACS2,SlACS4),color formation(SlGgpps2,SlSGR1),and cell wall metabolism(SlPG2a,SlPL,SlCEL2,and SlEXP1)are direct targets of NOR-like1.Electrophoretic mobility shift assays(EMSA),chromatin immunoprecipitation-quantitative PCR(ChIP-qPCR),and dual-luciferase reporter assay(DLR)confirmed that NOR-like1 bound to the promoters of these genes both in vitro and in vivo,and activated their expression.Our findings demonstrate that NOR-like1 is a new positive regulator of tomato fruit ripening,with an important role in the transcriptional regulatory network.
文摘Botrytis cinerea is a necrotrophic fungal pathogen that impacts a wide range of hosts, including Arabidopsis. Pretreatment with nitric oxide (NO) donor sodium nitroprusside (SNP) on Arabidopsis leaves suppressed Botrytis cinerea infection development. Additionally, in this study the dosage levels of SNP applied to the leaves had no direct, toxic impact on the development of the pathogen. The relationship between NO and reactive oxidant species (ROS) was studied by using both spectrophotometrical methods and staining leaf material with fluorescent dyes, nitro blue tetrazolium (NBT), and with 3,3-diaminobenzidine (DAB). The results showed that exogenous NO restrained the generation of ROS, especially H2O2, as the pathogen interacted with the Arabidopsis plant. And this inhibition of reactive oxidant burst coincided with delay infection development in NO-supplied leaves. The influence of elevated level of NO on antioxidant enzymes was investigated in this study. The activities of catalase (CAT) and guaiacol peroxidase (POD) were increased to different degrees in both: 1) SNP treated only leaves, and 2) SNP pretreated leaves that were subsequently inoculateted with pathogens. However, the activity of superoxide dismutase (SOD) was unchanged in the leaves studied. The decrease in H2O2 content probably resulted from the increase in activities of POD and CAT. Our study suggests that NO might trigger some metabolic reactions, i.e. enhanced enzyme activity that restrains H2O2 which ultimately results in resistance to B. cinerea infection.
文摘To the Editor:Severe acute pancreatitis(SAP)is a common critical disease in gastroenterology,and 69.3%of patients have acute kidney injury(AKI).^([1])Early diagnosis and treatment are very important in improving the prognosis of these patients.In recent years,machine learning models have been widely used in the medical field due to their excellent prediction performance.Some scholars have developed machine learning models that can solve the AKI prediction problem in specific populations and achieved good results.^([2])However,considering that the occurrence of AKI in patients with pancreatitis is also closely related to factors such as amylase and inflammatory markers,it is necessary to construct an AKI prediction model for the pancreatitis population.
基金funded by the Singapore Ministry of Education Academic Research Funds Tier 2(MOE-T2EP50220-0015)the Ministry of Education under the Research Centres of Excellence programme,the Ministry of Education,Decentralized GAP Funding(TAP2002020-05-18)+1 种基金NUS Efforts Against COVID-19(NUSEAC)FundingNational Research Foundation(NRF)of Singapore,through its NRF Investigator-ship Programme(NRF-NRFI2016-03).
文摘The significance of early detection and isolation of infected individuals,along with the quantitative assessment of antibodies against the virus,has gained widespread recognition during the ongoing covid-19 pandemic.This necessitates the development of cost-effective,user-friendly,decentralized testing methods characterized by both high sensitivity and specificity.In this article,we present a comprehensive review of an innovative,low-cost rapid decentralized immunoassay technology,applicable across various diagnostic and quantitative testing scenarios.Distinguishing itself from conventional immunoassay technologies,this method is featured with mechanically enhanced specificity without compromising sensitivity.We delve into the basic principle of the technology and a comparative analysis of this technology in relation to other immunodiagnostic methods,highlighting its potential applications in a wide spectrum of diagnostic tests.
基金supported by grants from the Natural Science Foundation of China(31270567,31210103911,31421063,31200410 and 31470566)the National Scientific and Technical Foundation Project of China(2012FY112000).
文摘As an apex predator the Amur tiger(Panthera tigris altaica)could play a pivotal role in maintaining the integrity of forest ecosystems in Northeast Asia.Due to habitat loss and harvest over the past century,tigers rapidly declined in China and are now restricted to the Russian Far East and bordering habitat in nearby China.To facilitate restoration of the tiger in its historical range,reliable estimates of population size are essential to assess effectiveness of conservation interventions.Here we used camera trap data collected in Hunchun National Nature Reserve from April to June 2013 and 2014 to estimate tiger density and abundance using both maximum likelihood and Bayesian spatially explicit capture-recapture(SECR)methods.A minimum of 8 individuals were detected in both sample periods and the documentation of marking behavior and reproduction suggests the presence of a resident population.Using Bayesian SECR modeling within the 11400 km2 state space,density estimates were 0.33 and 0.40 individuals/100 km^(2) in 2013 and 2014,respectively,corresponding to an estimated abundance of 38 and 45 animals for this transboundary Sino-Russian population.In a maximum likelihood framework,we estimated densities of 0.30 and 0.24 individuals/100 km^(2) corresponding to abundances of 34 and 27,in 2013 and 2014,respectively.These density estimates are comparable to other published estimates for resident Amur tiger populations in the Russian Far East.This study reveals promising signs of tiger recovery in Northeast China,and demonstrates the importance of connectivity between the Russian and Chinese populations for recovering tigers in Northeast China.
基金the following foundation:National Natural Science Foundation of China(NSFC 51803165)Natural Science Basic Research Plan in Shaanxi Province of China(2019JQ-167)+2 种基金Fundamental Research Funds for the Central Universities(xjj2018050 and xzy022019070)“Young Talent Support Plan”of Xi’an Jiaotong Universitythe Opening Project of Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research,College of Stomatology,Xi’an Jiaotong University(2019LHM-KFKT007)。
文摘The treatment of diabetic chronic wounds remains a global challenge due to the up-regulated inflammation response,oxidant stress,and persistent infection during healing process.Developing wound dressing materials with ideal biocompatibility,adequate mechanical strength,considerable under-water adhesion,sufficient anti-inflammation,antioxidant,and antibacterial properties is on-demand for clinical applications.In this study,we developed a bioactive skin-mimicking hydrogel band-aid through the combination of tannic acid(TA)and imidazolidinyl urea reinforced polyurethane(PMI)(TAP hydrogel)and explored its potentials in various medical applications,including hemostasis,normal skin incision,full-thickness skin wounds,and bacterial-infection skin incision on diabetic mice.TA was loaded into PMI hydrogel network to enhance the mechanical properties of TAP hydrogels through multiple non-covalent interactions(break strength:0.28-0.64 MPa;elongation at break:650-930%),which could resist the local stress and maintain the structural integrity of wound dressings during applications.Moreover,owing to the promising moisture-resistant adhesiveness and organ hemostasis,outstanding anti-inflammation,antibacterial,and antioxidant properties,TAP hydrogels could efficiently promote the recovery of skin incision and defects on diabetic mice.To further simulate the practical situation and explore the potential in clinical application,we also verified the treatment efficiency of TAP hydrogel in S.aureus-infected skin incision model on diabetic mice.
基金the National Natural Science Foundation of China(NSFC 52173139)the Shaanxi International Science and Technology Cooperation Program Project(2020KW-062)+1 种基金the“Young Talent Support Plan”of Xi’an Jiaotong University,and Fundamental Research Funds for the Central Universities(xzy022021040)supported by the Opening Research Fund from Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research,College of Stomatology,Xi’an Jiaotong University(2021LHM-KFKT003).
文摘Development of biocompatible hydrogel adhesives with robust tissue adhesion to realize instant hemorrhage control and injury sealing,especially for emergency rescue and tissue repair,is still challenging.Herein,we report a potent hydrogel adhesive by free radical polymerization of N-acryloyl aspartic acid(AASP)in a facile and straightforward way.Through delicate adjustment of steric hindrance,the synergistic effect between interface interactions and cohesion energy can be achieved in PAASP hydrogel verified by X-ray photoelectron spectroscopy(XPS)analysis and simulation calculation compared to poly(N-acryloyl glutamic acid)(PAGLU)and poly(N-acryloyl amidomalonic acid)(PAAMI)hydrogels.The adhesion strength of the PAASP hydrogel could reach 120 kPa to firmly seal the broken organs to withstand the external force with persistent stability under physiological conditions,and rapid hemostasis in different hemorrhage models on mice is achieved using PAASP hydrogel as physical barrier.Furthermore,the paper-based Fe^(3+)transfer printing method is applied to construct PAASP-based Janus hydrogel patch with both adhesive and non-adhesive surfaces,by which simultaneous wound healing and postoperative anti-adhesion can be realized in gastric perforation model on mice.This advanced hydrogel may show vast potential as bio-adhesives for emergency rescue and tissue/organ repair.
基金the National Natural Science Foundation of China(grant nos.91856109 and 21772239)the Fundamental Research Funds for the Central Universities(grant no.20lgzd21)the Leading Scientific,Technical and Innovation Talents of Guangdong Special Support Program(grant no.2019TX05Y638)for financial support.
文摘P-chirogenic compounds have been applied in different fields,especially in asymmetric catalysis as ligands and organocatalysts.However,broader applicability has been severely restricted by the lack of efficient synthetic methods.Consequently,developing efficient methods to access these compounds is of high synthetic value.Herein,we report a convenient,efficient,and unprecedented pathway to construct valuable P-chirogenic compounds via chiral selenide-catalyzed enantioselective electrophilic aromatic halogenation.Using a new chiral bifunctional selenide as the catalyst,a variety of bis(2-hydroxyaryl)aryl phosphine oxides were efficiently converted to the corresponding chlorinated and brominated P-chirogenic compounds with good to excellent enantioselectivities.By slightly adjusting the catalyst and solvent,this method is also able to prepare chiral alkyl diaryl phosphine oxides and diaryl phosphinates.Furthermore,control experiments revealed the decomposition pathways of catalysts and the possible reasons why chiral selenide catalyst was more effective than chiral sulfide catalyst.The effect of hydrogen bonding was studied,and the reason why the chlorination took place on the various aromatic rings was elucidated when the substrates were switched from triaryl phosphine oxides to alkyl diaryl phosphine oxides and diaryl phosphinates.
基金Project supported by the National Natural Science Foundation of China(Nos.61575138,61307069,51205273)the Top Young Academic Leaders and the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi
文摘By inserting an air cavity into a one-dimensional photonic crystal of LiF/GaSb, a tunable filter covering the whole visible range is proposed. Following consideration of the dispersion of the materials, through modulating the thickness of the air cavity, we demonstrate that a single resonant peak can shift from 416.1 to 667.3 nm in the band gap at normal incidence by means of the transfer matrix method. The research also shows that the transmittance of the channel can be maximized when the number of periodic Li F/Ga Sb layers on one side of the air defect layer is equal to that of the other side. When adding a period to both sides respectively, the full width at half maximum of the defect mode is reduced by one order of magnitude. This structure will provide a promising approach to fabricate practical tunable filters in the visible region with ultra-wide tuning range.
基金the National Natural Science Foundation of China(grant nos.91856109 and 21772239)the Fundamental Research Funds for the Central Universities(grant no.20lgzd21)the Leading Scientific,Technical and Innovation Talents of Guangdong Special Support Program(grant no.2019TX05Y638)for financial support.
文摘Chiral benzo-fused N-heterocycles are frequently found in natural and synthetic products.However,their synthesis usually suffers from different limitations such as difficulty in accessing appropriate starting materials and unsatisfactory stereoselectivities.In this work,an unprecedented chiral sulfide-catalyzed enantioselective Friedel-Crafts-type electrophilic chlorination is shown to construct various 3,4-functionalized tetrahydroquinolines with excellent enantio-and diastereoselectivities from readily available aniline derivatives.Interestingly,employing N-allyl 1-naphthanilides as substrates,divergent reactions via chlorocarbocyclization and dearomatization occurred to afford two chiral polycyclic benzo-fused N-heterocycles.The system that we developed extends the scope of asymmetric chlorination to general substrateswithout the need of a N-H group,and significantly promotes the synthesis of enantioenriched benzo-fused N-heterocycles.