The spatial distributions of different kinds of ions are usually not completely the same in the process of extracting.In order to study the reason for the different characteristics of ion extraction, a simplified simu...The spatial distributions of different kinds of ions are usually not completely the same in the process of extracting.In order to study the reason for the different characteristics of ion extraction, a simplified simulation model of Cu+ andCr+ ions extraction process was established by 2D3V (two-dimensional in space and three- dimensional in velocity space)particle-in-cell (PIC) method. The effects of different extraction voltages from 0 V to 500 V on the density distribution ofCu+ and Cr+ ions and the change of plasma emission surface were analyzed. On the basis of this model, the ion densitydistribution characteristics of Cu+ ions mixed with Li+, Mg+, K+, Fe+, Y+, Ag+, Xe+, Au+, and Pb+ ions respectivelyunder 200-V extraction voltage are further simulated, and it is revealed that the atomic mass of the ions is the key reason fordifferent ion density distributions when different kinds of ions are mixed and extracted, which provides support for furtherunderstanding of ion extraction characteristics.展开更多
In current wireless communication and electronic systems,digital signals and electromagnetic(EM)radiation are processed by different modules.Here,we propose a mechanism to fuse the modulation of digital signals and th...In current wireless communication and electronic systems,digital signals and electromagnetic(EM)radiation are processed by different modules.Here,we propose a mechanism to fuse the modulation of digital signals and the manipulation of EM radiation on a single programmable metasurface(PM).The PM consists of massive subwavelength-scale digital coding elements.A set of digital states of all elements forms simultaneous digital information roles for modulation and the wave-control sequence code of the PM.By designing digital coding sequences in the spatial and temporal domains,the digital information and farfield patterns of the PM can be programmed simultaneously and instantly in desired ways.For the experimental demonstration of the mechanism,we present a programmable wireless communication system.The same system can realize transmissions of digital information in single-channel modes with beamsteerable capability and multichannel modes with multiple independent information.The measured results show the excellent performance of the programmable system.This work provides excellent prospects for applications in fifth-or sixth-generation wireless communications and modern intelligent platforms for unmanned aircrafts and vehicles.展开更多
The electromagnetic satellite Zhangheng 01(ZH-01) was successfully launched on February 2, 2018. The GNSS Radio Occultation(GRO) receiver on board the satellite is able to observe the occultation events of GPS and Bei...The electromagnetic satellite Zhangheng 01(ZH-01) was successfully launched on February 2, 2018. The GNSS Radio Occultation(GRO) receiver on board the satellite is able to observe the occultation events of GPS and BeiDou navigation satellites. We analyzed the data acquired during the in-orbit testing period. We concludes that the GRO ionosphere inversion results are reasonable,the trend is correct, the satellite can observe about 600 ionosphere occultation events each day. The global coverage of more than 30000 consecutive GRO events in more than two months were analyzed and compared with COSMIC observations: both the GRO and COSMIC occultation can realize global coverage: the Nm F2 and Hm F2 global distributions are similar and change obviously with latitude. We used three digisondes at different latitudes to analyze and compare the spatio-temporally consistent GRO data: the RMSE of GRO Nm F2 relative to digisonde is better than 9.41%, the correlation coefficient is better than 0.8682: the relative RMSE of Hm F2 is better than 7.80% and the correlation coefficient is better than 0.7066.展开更多
The programmable metasurface(PM)is an antenna array architecture that realizes flexible beam steering.This functionality is achieved by controlling the unit cells designed with micro components such as positive-intrin...The programmable metasurface(PM)is an antenna array architecture that realizes flexible beam steering.This functionality is achieved by controlling the unit cells designed with micro components such as positive-intrinsic-negative(PIN)diodes,which offers potential cost reductions in the next generation wireless communication systems.Although PM has been a popular topic in antenna design,its implementations in real-time systems accompanied by signal processing algorithms are challenging.In this paper,novel predictive tracking algorithms for mobile communication scenarios using a PM are created and implemented in a real-time system operating at 28 GHz.An angular speed prediction(ASP)algorithm is proposed to compute the position of user equipment(UE)based on the previously recorded beam directions.As another solution,an angle correction(AC)algorithm is proposed to further improve the prediction and tracking accuracy.As a benchmark,the comparisons to a previous PM tracking algorithm without prediction are presented.Both simulation and measurement results show that the prediction algorithms successfully improve the tracking performance,which also prove the feasibilities of PM-based systems to solve complex real-time signal processing problems.展开更多
Objective:To study the correlation of CD40 ligand (CD40L) and CXC ligand (CXCL5) expression with inflammatory response and plaque properties in patients with coronary heart disease.Methods: Patients who were diagnosed...Objective:To study the correlation of CD40 ligand (CD40L) and CXC ligand (CXCL5) expression with inflammatory response and plaque properties in patients with coronary heart disease.Methods: Patients who were diagnosed with coronary heart disease in Xiantao First People's Hospital in Hubei Province between February 2015 and April 2017 were selected as the CHD group of the study, and healthy volunteers who received physical examination during the same period were selected the control group. The peripheral blood was collected to separate RNA, and the CD40L and CXCL5 expression were determined;peripheral blood was collected to separate serum, and the contents of inflammatory response indexes, lipid metabolism indexes and collagen metabolism indexes were determined.Results: CD40L and CXCL5 mRNA expression in peripheral blood of CHD group were significantly higher than those of control group;TNF-α, IFN-γ, IL-6, PCSK9, sdLDLC, ox-LDL, Gal-3, Lp-PLA2, ICTP, ADAMTS4, CatK and CyPA contents in serum of CHD group were significantly higher than those of control group whereas IL-10, TGF-β1, TIMP1 and TIMP2 contents were significantly lower than those of control group;CD40L and CXCL5 expression in peripheral blood were positively correlated with TNF-α, IFN-γ, IL-6, PCSK9, sdLDLC, ox-LDL, Gal-3, Lp-PLA2, ICTP, ADAMTS4, CatK and CyPA contents in serum, and negatively correlated with IL-10, TGF-β1, TIMP1 and TIMP2 contents.Conclusion: Abnormal high expression of CD40L and CXCL5 can aggravate the inflammatory response and reduce the plaque stability in patients with coronary heart disease.展开更多
The generation of mature and healthy oocytes is the most critical event in the entire female reproductive process,and the mechanisms regulating this process remain to be studied.Here,we demonstrate that Smith-like(LSM...The generation of mature and healthy oocytes is the most critical event in the entire female reproductive process,and the mechanisms regulating this process remain to be studied.Here,we demonstrate that Smith-like(LSM)family member 14B(LSM14B)regulates oocyte maturation,and the loss of LSM14B in mouse ovaries leads to abnormal oocyte MII arrest and female infertility.Next,we find the aberrant transcriptional activation,indicated by abnormal non-surrounded nucleolus and surrounded nucleolus oocyte proportions,and abnormal chromosome assembly and segregation in Lsm14b-deficient mouse oocytes.The global transcriptome analysis suggests that many transcripts involved in cytoplasmic processing body(P-body)function are altered in Lsm14b-deficient mouse oocytes.Deletion of Lsm14b results in the expression and/or localization changes of P-body components(such as LSM14A,DCP1A,and 4E-T).Notably,DDX6,a key component of the P-body,is downregulated and accumulates in the nuclei in Lsm14b-deficient mouse oocytes.Taken together,our data suggest that LSM14B links mouse oocyte maturation to female fertility through the regulation of the P-body.展开更多
Metamaterials are artificial structures that are usually described by effective medium parameters on the macroscopic scale,and these metamaterials are referred to as‘analog metamaterials’.Here,we propose‘digital me...Metamaterials are artificial structures that are usually described by effective medium parameters on the macroscopic scale,and these metamaterials are referred to as‘analog metamaterials’.Here,we propose‘digital metamaterials’through two steps.First,we present‘coding metamaterials’that are composed of only two types of unit cells,with 0 and p phase responses,which we name‘0’and‘1’elements,respectively.By coding‘0’and‘1’elements with controlled sequences(i.e.,1-bit coding),we can manipulate electromagnetic(EM)waves and realize different functionalities.The concept of coding metamaterials can be extended from 1-bit coding to 2-bit coding or higher.In 2-bit coding,four types of unit cells,with phase responses of 0,p/2,p,and 3p/2,are required to mimic the‘00’,‘01’,‘10’and‘11’elements,respectively.The 2-bit coding has greater freedom than 1-bit coding for controlling EM waves.Second,we propose a unique metamaterial particle that has either a‘0’or‘1’response controlled by a biased diode.Based on this particle,we present‘digital metamaterials’with unit cells that possess either a‘0’or‘1’state.Using a field-programmable gate array,we realize digital control over the digital metamaterial.By programming different coding sequences,a single digital metamaterial has the ability to manipulate EM waves in different manners,thereby realizing‘programmable metamaterials’.The above concepts and physical phenomena are confirmed through numerical simulations and experiments using metasurfaces.展开更多
Metamaterials based on effective media can be used to produce a number of unusual physical properties(for example,negative refraction and invisibility cloaking)because they can be tailored with effective medium parame...Metamaterials based on effective media can be used to produce a number of unusual physical properties(for example,negative refraction and invisibility cloaking)because they can be tailored with effective medium parameters that do not occur in nature.Recently,the use of coding metamaterials has been suggested for the control of electromagnetic waves through the design of coding sequences using digital elements‘0’and‘1,'which possess opposite phase responses.Here we propose the concept of an anisotropic coding metamaterial in which the coding behaviors in different directions are dependent on the polarization status of the electromagnetic waves.We experimentally demonstrate an ultrathin and flexible polarization-controlled anisotropic coding metasurface that functions in the terahertz regime using specially designed coding elements.By encoding the elements with elaborately designed coding sequences(both 1-bit and 2-bit sequences),the x-and y-polarized waves can be anomalously reflected or independently diffused in three dimensions.The simulated far-field scattering patterns and near-field distributions are presented to illustrate the dual-functional performance of the encoded metasurface,and the results are consistent with the measured results.We further demonstrate the ability of the anisotropic coding metasurfaces to generate a beam splitter and realize simultaneous anomalous reflections and polarization conversions,thus providing powerful control of differently polarized electromagnetic waves.The proposed method enables versatile beam behaviors under orthogonal polarizations using a single metasurface and has the potential for use in the development of interesting terahertz devices.展开更多
A digital-coding programmable metasurface(DCPM)is a type of functional system that is composed of subwavelength-scale digital coding elements with opposite phase responses.By configuring the digital coding elements,a ...A digital-coding programmable metasurface(DCPM)is a type of functional system that is composed of subwavelength-scale digital coding elements with opposite phase responses.By configuring the digital coding elements,a DCPM can construct dynamic near-field image patterns in which the intensity of each pixel of the image can be dynamically and independently modulated.Thus,a DCPM can perform both spatial and temporal modulations.Here,this advantage is used to realize multichannel direct transmissions of near-field information.Three points are selected in the near-field region to form three independent channels.By applying various digital phase codes on the DCPM,independent binary digital symbols defined by amplitude codes(namely,weak and strong amplitudes)are transmitted through the three channels.The measured near-field distributions and temporal transmissions of the system agree with numerical calculations.Compared with the conventional multichannel transmission,the proposed mechanism achieves simultaneous spatial and temporal modulations by treating DCPM as an energy radiator and information modulator,thereby enduing DCPM with high potential in near-field information processing and communications.展开更多
Background:Infectious diseases such as SARS and H1N1 can significantly impact people’s lives and cause severe social and economic damages.Recent outbreaks have stressed the urgency of effective research on the dynami...Background:Infectious diseases such as SARS and H1N1 can significantly impact people’s lives and cause severe social and economic damages.Recent outbreaks have stressed the urgency of effective research on the dynamics of infectious disease spread.However,it is difficult to predict when and where outbreaks may emerge and how infectious diseases spread because many factors affect their transmission,and some of them may be unknown.Methods:One feasible means to promptly detect an outbreak and track the progress of disease spread is to implement surveillance systems in regional or national health and medical centres.The accumulated surveillance data,including temporal,spatial,clinical,and demographic information can provide valuable information that can be exploited to better understand and model the dynamics of infectious disease spread.The aim of this work is to develop and empirically evaluate a stochastic model that allows the investigation of transmission patterns of infectious diseases in heterogeneous populations.Results:We test the proposed model on simulation data and apply it to the surveillance data from the 2009 H1N1 pandemic in Hong Kong.In the simulation experiment,our model achieves high accuracy in parameter estimation(less than 10.0%mean absolute percentage error).In terms of the forward prediction of case incidence,the mean absolute percentage errors are 17.3%for the simulation experiment and 20.0%for the experiment on the real surveillance data.Conclusion:We propose a stochastic model to study the dynamics of infectious disease spread in heterogeneous populations from temporal-spatial surveillance data.The proposed model is evaluated using both simulated data and the real data from the 2009 H1N1 epidemic in Hong Kong and achieves acceptable prediction accuracy.We believe that our model can provide valuable insights for public health authorities to predict the effect of disease spread and analyse its underlying factors and to guide new control efforts.展开更多
Long-segment lichen sclerosus(LS)urethral stricture is a challenge for urologists.Limited data are available for surgeons to make a surgical decision between Kulkarni and Asopa urethroplasty.In this retrospective stud...Long-segment lichen sclerosus(LS)urethral stricture is a challenge for urologists.Limited data are available for surgeons to make a surgical decision between Kulkarni and Asopa urethroplasty.In this retrospective study,we investigated the outcomes of these two procedures in patients with LS urethral stricture.Between January 2015 and December 2020,77 patients with LS urethral stricture underwent Kulkarni and Asopa procedures for urethroplasty in the Department of Urology,Shanghai Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine(Shanghai,China).Of the 77 patients,42(54.5%)underwent the Asopa procedure and 35(45.5%)underwent the Kulkarni procedure.The overall complication rate was 34.2%in the Kulkarni group and 19.0%in the Asopa group,and no difference was observed(P=0.105).Among the complications,no statistical difference was observed in the incidence of urethral stricture recurrence(P=0.724)or glans dehiscence(P=0.246)except for postoperative meatus stenosis(P=0.020).However,the recurrence-free survival rate between the two procedures was significantly different(P=0.016).Cox survival analysis showed that antiplatelet/anticoagulant therapy use(P=0.020),diabetes(P=0.003),current/former smoking(P=0.019),coronary heart disease(P<0.001),and stricture length(P=0.028)may lead to a higher hazard ratio of complications.Even so,these two techniques can still provide acceptable results with their own advantages in the surgical treatment of LS urethral strictures.The surgical alternative should be considered comprehensively according to the patient characteristics and surgeon preferences.Moreover,our results showed that antiplatelet/anticoagulant therapy use,diabetes,coronary heart disease,current/former smoking,and stricture length may be contributing factors of complications.Therefore,patients with LS are advised to undergo early interventions for better therapeutic effects.展开更多
基金the Presidential Foundation of China Academy of Engineering Physics(Grant No.YZJJZQ2022016)the National Natural Science Foun-dation of China(Grant No.52207177).
文摘The spatial distributions of different kinds of ions are usually not completely the same in the process of extracting.In order to study the reason for the different characteristics of ion extraction, a simplified simulation model of Cu+ andCr+ ions extraction process was established by 2D3V (two-dimensional in space and three- dimensional in velocity space)particle-in-cell (PIC) method. The effects of different extraction voltages from 0 V to 500 V on the density distribution ofCu+ and Cr+ ions and the change of plasma emission surface were analyzed. On the basis of this model, the ion densitydistribution characteristics of Cu+ ions mixed with Li+, Mg+, K+, Fe+, Y+, Ag+, Xe+, Au+, and Pb+ ions respectivelyunder 200-V extraction voltage are further simulated, and it is revealed that the atomic mass of the ions is the key reason fordifferent ion density distributions when different kinds of ions are mixed and extracted, which provides support for furtherunderstanding of ion extraction characteristics.
基金supported by the Fund for International Cooperation and Exchange of National Natural Science Foundation of China(61761136007)the National Key Research and Development Program of China(2017YFA0700201,2017YFA0700202,and 2017YFA0700203)+3 种基金the National Natural Science Foundation of China(6217010363,61631007,61571117,61501112,61501117,61871109,61522106,61731010,61735010,61722106,61701107,and 61701108)the Natural Science Foundation of Jiangsu Province(BK20211161)the 111 Project(111-2-05)ZhiShan Young Scholar Program of Southeast University.
文摘In current wireless communication and electronic systems,digital signals and electromagnetic(EM)radiation are processed by different modules.Here,we propose a mechanism to fuse the modulation of digital signals and the manipulation of EM radiation on a single programmable metasurface(PM).The PM consists of massive subwavelength-scale digital coding elements.A set of digital states of all elements forms simultaneous digital information roles for modulation and the wave-control sequence code of the PM.By designing digital coding sequences in the spatial and temporal domains,the digital information and farfield patterns of the PM can be programmed simultaneously and instantly in desired ways.For the experimental demonstration of the mechanism,we present a programmable wireless communication system.The same system can realize transmissions of digital information in single-channel modes with beamsteerable capability and multichannel modes with multiple independent information.The measured results show the excellent performance of the programmable system.This work provides excellent prospects for applications in fifth-or sixth-generation wireless communications and modern intelligent platforms for unmanned aircrafts and vehicles.
文摘The electromagnetic satellite Zhangheng 01(ZH-01) was successfully launched on February 2, 2018. The GNSS Radio Occultation(GRO) receiver on board the satellite is able to observe the occultation events of GPS and BeiDou navigation satellites. We analyzed the data acquired during the in-orbit testing period. We concludes that the GRO ionosphere inversion results are reasonable,the trend is correct, the satellite can observe about 600 ionosphere occultation events each day. The global coverage of more than 30000 consecutive GRO events in more than two months were analyzed and compared with COSMIC observations: both the GRO and COSMIC occultation can realize global coverage: the Nm F2 and Hm F2 global distributions are similar and change obviously with latitude. We used three digisondes at different latitudes to analyze and compare the spatio-temporally consistent GRO data: the RMSE of GRO Nm F2 relative to digisonde is better than 9.41%, the correlation coefficient is better than 0.8682: the relative RMSE of Hm F2 is better than 7.80% and the correlation coefficient is better than 0.7066.
文摘The programmable metasurface(PM)is an antenna array architecture that realizes flexible beam steering.This functionality is achieved by controlling the unit cells designed with micro components such as positive-intrinsic-negative(PIN)diodes,which offers potential cost reductions in the next generation wireless communication systems.Although PM has been a popular topic in antenna design,its implementations in real-time systems accompanied by signal processing algorithms are challenging.In this paper,novel predictive tracking algorithms for mobile communication scenarios using a PM are created and implemented in a real-time system operating at 28 GHz.An angular speed prediction(ASP)algorithm is proposed to compute the position of user equipment(UE)based on the previously recorded beam directions.As another solution,an angle correction(AC)algorithm is proposed to further improve the prediction and tracking accuracy.As a benchmark,the comparisons to a previous PM tracking algorithm without prediction are presented.Both simulation and measurement results show that the prediction algorithms successfully improve the tracking performance,which also prove the feasibilities of PM-based systems to solve complex real-time signal processing problems.
文摘Objective:To study the correlation of CD40 ligand (CD40L) and CXC ligand (CXCL5) expression with inflammatory response and plaque properties in patients with coronary heart disease.Methods: Patients who were diagnosed with coronary heart disease in Xiantao First People's Hospital in Hubei Province between February 2015 and April 2017 were selected as the CHD group of the study, and healthy volunteers who received physical examination during the same period were selected the control group. The peripheral blood was collected to separate RNA, and the CD40L and CXCL5 expression were determined;peripheral blood was collected to separate serum, and the contents of inflammatory response indexes, lipid metabolism indexes and collagen metabolism indexes were determined.Results: CD40L and CXCL5 mRNA expression in peripheral blood of CHD group were significantly higher than those of control group;TNF-α, IFN-γ, IL-6, PCSK9, sdLDLC, ox-LDL, Gal-3, Lp-PLA2, ICTP, ADAMTS4, CatK and CyPA contents in serum of CHD group were significantly higher than those of control group whereas IL-10, TGF-β1, TIMP1 and TIMP2 contents were significantly lower than those of control group;CD40L and CXCL5 expression in peripheral blood were positively correlated with TNF-α, IFN-γ, IL-6, PCSK9, sdLDLC, ox-LDL, Gal-3, Lp-PLA2, ICTP, ADAMTS4, CatK and CyPA contents in serum, and negatively correlated with IL-10, TGF-β1, TIMP1 and TIMP2 contents.Conclusion: Abnormal high expression of CD40L and CXCL5 can aggravate the inflammatory response and reduce the plaque stability in patients with coronary heart disease.
基金supported by the National Key R&D Program of China(2021YFC2700201 to X.W.)the National Natural Science Foundation of China(32070831,32270897 to X.W.).
文摘The generation of mature and healthy oocytes is the most critical event in the entire female reproductive process,and the mechanisms regulating this process remain to be studied.Here,we demonstrate that Smith-like(LSM)family member 14B(LSM14B)regulates oocyte maturation,and the loss of LSM14B in mouse ovaries leads to abnormal oocyte MII arrest and female infertility.Next,we find the aberrant transcriptional activation,indicated by abnormal non-surrounded nucleolus and surrounded nucleolus oocyte proportions,and abnormal chromosome assembly and segregation in Lsm14b-deficient mouse oocytes.The global transcriptome analysis suggests that many transcripts involved in cytoplasmic processing body(P-body)function are altered in Lsm14b-deficient mouse oocytes.Deletion of Lsm14b results in the expression and/or localization changes of P-body components(such as LSM14A,DCP1A,and 4E-T).Notably,DDX6,a key component of the P-body,is downregulated and accumulates in the nuclei in Lsm14b-deficient mouse oocytes.Taken together,our data suggest that LSM14B links mouse oocyte maturation to female fertility through the regulation of the P-body.
基金This work was supported in part by the National High Tech(863)Projects(2012AA030402 and 2011AA010202)in part by the National Science Foundation of China(61138001,60990320 and 60990324)in part by the 111 Project(111-2-05)and in part by the Joint Research Center on Terahertz Science.
文摘Metamaterials are artificial structures that are usually described by effective medium parameters on the macroscopic scale,and these metamaterials are referred to as‘analog metamaterials’.Here,we propose‘digital metamaterials’through two steps.First,we present‘coding metamaterials’that are composed of only two types of unit cells,with 0 and p phase responses,which we name‘0’and‘1’elements,respectively.By coding‘0’and‘1’elements with controlled sequences(i.e.,1-bit coding),we can manipulate electromagnetic(EM)waves and realize different functionalities.The concept of coding metamaterials can be extended from 1-bit coding to 2-bit coding or higher.In 2-bit coding,four types of unit cells,with phase responses of 0,p/2,p,and 3p/2,are required to mimic the‘00’,‘01’,‘10’and‘11’elements,respectively.The 2-bit coding has greater freedom than 1-bit coding for controlling EM waves.Second,we propose a unique metamaterial particle that has either a‘0’or‘1’response controlled by a biased diode.Based on this particle,we present‘digital metamaterials’with unit cells that possess either a‘0’or‘1’state.Using a field-programmable gate array,we realize digital control over the digital metamaterial.By programming different coding sequences,a single digital metamaterial has the ability to manipulate EM waves in different manners,thereby realizing‘programmable metamaterials’.The above concepts and physical phenomena are confirmed through numerical simulations and experiments using metasurfaces.
基金supported by the National Science Foundation of China(61571117,61522106,61138001,61302018 and 61401089)Natural Science Foundation of the Jiangsu Province(BK2012019)the 111 Project(111-2-05).
文摘Metamaterials based on effective media can be used to produce a number of unusual physical properties(for example,negative refraction and invisibility cloaking)because they can be tailored with effective medium parameters that do not occur in nature.Recently,the use of coding metamaterials has been suggested for the control of electromagnetic waves through the design of coding sequences using digital elements‘0’and‘1,'which possess opposite phase responses.Here we propose the concept of an anisotropic coding metamaterial in which the coding behaviors in different directions are dependent on the polarization status of the electromagnetic waves.We experimentally demonstrate an ultrathin and flexible polarization-controlled anisotropic coding metasurface that functions in the terahertz regime using specially designed coding elements.By encoding the elements with elaborately designed coding sequences(both 1-bit and 2-bit sequences),the x-and y-polarized waves can be anomalously reflected or independently diffused in three dimensions.The simulated far-field scattering patterns and near-field distributions are presented to illustrate the dual-functional performance of the encoded metasurface,and the results are consistent with the measured results.We further demonstrate the ability of the anisotropic coding metasurfaces to generate a beam splitter and realize simultaneous anomalous reflections and polarization conversions,thus providing powerful control of differently polarized electromagnetic waves.The proposed method enables versatile beam behaviors under orthogonal polarizations using a single metasurface and has the potential for use in the development of interesting terahertz devices.
基金supported by Fund for International Cooperation and Exchange of National Natural Science Foundation of China(61761136007)the National Key Research and Development Program of China(2017YFA0700201,2017YFA0700202,2017YFA0700203)+2 种基金the National Natural Science Foundation of China(61631007,61571117,61501112,61501117,61522106,61731010,61735010,61722106,61701107,and 61701108)the 111 Project(111-2-05)Zhishan Young Scholar Program of Southeast University.
文摘A digital-coding programmable metasurface(DCPM)is a type of functional system that is composed of subwavelength-scale digital coding elements with opposite phase responses.By configuring the digital coding elements,a DCPM can construct dynamic near-field image patterns in which the intensity of each pixel of the image can be dynamically and independently modulated.Thus,a DCPM can perform both spatial and temporal modulations.Here,this advantage is used to realize multichannel direct transmissions of near-field information.Three points are selected in the near-field region to form three independent channels.By applying various digital phase codes on the DCPM,independent binary digital symbols defined by amplitude codes(namely,weak and strong amplitudes)are transmitted through the three channels.The measured near-field distributions and temporal transmissions of the system agree with numerical calculations.Compared with the conventional multichannel transmission,the proposed mechanism achieves simultaneous spatial and temporal modulations by treating DCPM as an energy radiator and information modulator,thereby enduing DCPM with high potential in near-field information processing and communications.
基金supported by Hong Kong Baptist University Strategic Development FundHong Kong General Research Grant HKBU12202114。
文摘Background:Infectious diseases such as SARS and H1N1 can significantly impact people’s lives and cause severe social and economic damages.Recent outbreaks have stressed the urgency of effective research on the dynamics of infectious disease spread.However,it is difficult to predict when and where outbreaks may emerge and how infectious diseases spread because many factors affect their transmission,and some of them may be unknown.Methods:One feasible means to promptly detect an outbreak and track the progress of disease spread is to implement surveillance systems in regional or national health and medical centres.The accumulated surveillance data,including temporal,spatial,clinical,and demographic information can provide valuable information that can be exploited to better understand and model the dynamics of infectious disease spread.The aim of this work is to develop and empirically evaluate a stochastic model that allows the investigation of transmission patterns of infectious diseases in heterogeneous populations.Results:We test the proposed model on simulation data and apply it to the surveillance data from the 2009 H1N1 pandemic in Hong Kong.In the simulation experiment,our model achieves high accuracy in parameter estimation(less than 10.0%mean absolute percentage error).In terms of the forward prediction of case incidence,the mean absolute percentage errors are 17.3%for the simulation experiment and 20.0%for the experiment on the real surveillance data.Conclusion:We propose a stochastic model to study the dynamics of infectious disease spread in heterogeneous populations from temporal-spatial surveillance data.The proposed model is evaluated using both simulated data and the real data from the 2009 H1N1 epidemic in Hong Kong and achieves acceptable prediction accuracy.We believe that our model can provide valuable insights for public health authorities to predict the effect of disease spread and analyse its underlying factors and to guide new control efforts.
基金This work was supported by the Project of Shanghai Medical Innovation and Clinical Research(No.20Y11904300)the Clinical Research Project of Shanghai Municipal Health Commission(No.202040437).
文摘Long-segment lichen sclerosus(LS)urethral stricture is a challenge for urologists.Limited data are available for surgeons to make a surgical decision between Kulkarni and Asopa urethroplasty.In this retrospective study,we investigated the outcomes of these two procedures in patients with LS urethral stricture.Between January 2015 and December 2020,77 patients with LS urethral stricture underwent Kulkarni and Asopa procedures for urethroplasty in the Department of Urology,Shanghai Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine(Shanghai,China).Of the 77 patients,42(54.5%)underwent the Asopa procedure and 35(45.5%)underwent the Kulkarni procedure.The overall complication rate was 34.2%in the Kulkarni group and 19.0%in the Asopa group,and no difference was observed(P=0.105).Among the complications,no statistical difference was observed in the incidence of urethral stricture recurrence(P=0.724)or glans dehiscence(P=0.246)except for postoperative meatus stenosis(P=0.020).However,the recurrence-free survival rate between the two procedures was significantly different(P=0.016).Cox survival analysis showed that antiplatelet/anticoagulant therapy use(P=0.020),diabetes(P=0.003),current/former smoking(P=0.019),coronary heart disease(P<0.001),and stricture length(P=0.028)may lead to a higher hazard ratio of complications.Even so,these two techniques can still provide acceptable results with their own advantages in the surgical treatment of LS urethral strictures.The surgical alternative should be considered comprehensively according to the patient characteristics and surgeon preferences.Moreover,our results showed that antiplatelet/anticoagulant therapy use,diabetes,coronary heart disease,current/former smoking,and stricture length may be contributing factors of complications.Therefore,patients with LS are advised to undergo early interventions for better therapeutic effects.