Background:The high incidence of gallstone recurrence was a major concern for laparoscopic gallbladderpreserving surgery.This study aimed to investigate the risk factors for gallstone recurrence after gallbladder-pres...Background:The high incidence of gallstone recurrence was a major concern for laparoscopic gallbladderpreserving surgery.This study aimed to investigate the risk factors for gallstone recurrence after gallbladder-preserving surgery and to establish an individualized nomogram model to predict the risk of gallstone recurrence.Methods:The clinicopathological and follow-up data of 183 patients who were initially diagnosed with gallstones and treated with gallbladder-preserving surgery at our hospital from January 2012 to January 2019 were retrospectively collected.The independent predictive factors for gallstone recurrence following gallbladder-preserving surgery were identified by multivariate logistic regression analysis.A nomogram model for the prediction of gallstone recurrence was constructed based on the selected variables.The C-index,receiver operating characteristic(ROC)curve and calibration curve were used to evaluate the predictive power of the nomogram model for gallstone recurrence.Results:During the follow-up period,a total of 65 patients experienced gallstone recurrence,and the recurrence rate was 35.5%.Multivariate logistic regression analysis revealed that the course of gallstones>2 years[odds ratio(OR)=2.567,95%confidence interval(CI):1.270-5.187,P=0.009],symptomatic gallstones(OR=2.589,95%CI:1.059-6.329,P=0.037),multiple gallstones(OR=2.436,95%CI:1.133-5.237,P=0.023),history of acute cholecystitis(OR=2.778,95%CI:1.178-6.549,P=0.020)and a greasy diet(OR=2.319,95%CI:1.186-4.535,P=0.014)were independent risk factors for gallstone recurrence after gallbladder-preserving surgery.A nomogram model for predicting the recurrence of gallstones was established based on the above five variables.The results showed that the C-index of the nomogram model was 0.692,suggesting it was valuable to predict gallstone recurrence.Moreover,the calibration curve showed good consistency between the predicted probability and actual probability.Conclusions:The nomogram model for the prediction of gallstone recurrence might help clinicians develop a proper treatment strategy for patients with gallstones.Gallbladder-preserving surgery should be cautiously considered for patients with high recurrence risks.展开更多
Data assimilation(DA)and uncertainty quantification(UQ)are extensively used in analysing and reducing error propagation in high-dimensional spatial-temporal dynamics.Typical applications span from computational fluid ...Data assimilation(DA)and uncertainty quantification(UQ)are extensively used in analysing and reducing error propagation in high-dimensional spatial-temporal dynamics.Typical applications span from computational fluid dynamics(CFD)to geoscience and climate systems.Recently,much effort has been given in combining DA,UQ and machine learning(ML)techniques.These research efforts seek to address some critical challenges in high-dimensional dynamical systems,including but not limited to dynamical system identification,reduced order surrogate modelling,error covariance specification and model error correction.A large number of developed techniques and methodologies exhibit a broad applicability across numerous domains,resulting in the necessity for a comprehensive guide.This paper provides the first overview of state-of-the-art researches in this interdisciplinary field,covering a wide range of applications.This review is aimed at ML scientists who attempt to apply DA and UQ techniques to improve the accuracy and the interpretability of their models,but also at DA and UQ experts who intend to integrate cutting-edge ML approaches to their systems.Therefore,this article has a special focus on how ML methods can overcome the existing limits of DA and UQ,and vice versa.Some exciting perspectives of this rapidly developing research field are also discussed.Index Terms-Data assimilation(DA),deep learning,machine learning(ML),reduced-order-modelling,uncertainty quantification(UQ).展开更多
BACKGROUND B-mode-ultrasound-guided percutaneous cholecystostomy(PC)may be performed by a transhepatic or transperitoneal approach,called percutaneous transhepatic gallbladder drainage(PHGD)and percutaneous transperit...BACKGROUND B-mode-ultrasound-guided percutaneous cholecystostomy(PC)may be performed by a transhepatic or transperitoneal approach,called percutaneous transhepatic gallbladder drainage(PHGD)and percutaneous transperitoneal gallbladder drainage(PPGD),respectively.We compared the impact of PC related to the route of catheter placement on subsequent laparoscopic cholecystectomy(LC).AIM To compare the impact of PC related to the route of catheter placement on subsequent LC.METHODS We retrospectively studied 103 patients with acute calculous cholecystitis who underwent scheduled LC after PC between January 2010 and January 2019.Group I included 58 patients who underwent scheduled LC after PHGD.Group II included 45 patients who underwent scheduled LC after PPGD.Clinical outcomes were analyzed according to each group.RESULTS Baseline demographic characteristics did not differ significantly between both groups(P>0.05).Both PHGD and PPGD were able to quickly resolve cholecystitis sepsis.Group I showed significantly higher efficacy than group II in terms of lower pain score during puncture(3.1 vs 4.5;P=0.001)and at 12 h follow-up(1.5 vs 2.2;P=0.001),lower rate of fever within 24 h after PC(13.8%vs 42.2%;P=0.001),shorted operation duration(118.3 vs 139.6 min;P=0.001),lower amount of intraoperative bleeding(72.1 vs 109.4 mL;P=0.001)and shorter length of hospital stay(14.3 d vs 18.0 d;P=0.001).However,group II had significantly lower rate of local bleeding at the PC site(2.2%vs 20.7%;P=0.005)and lower rate of severe adhesion(33.5%vs 55.2%;P=0.048).No significant differences were noted between both groups regarding the conversion rate to laparotomy,rate of subtotal cholecystectomy,complications and pathology.CONCLUSION B-mode-ultrasound-guided PHGD is superior to PPGD followed by LC for treatment of acute calculous cholecystitis,with shorter operating time,minimal amount of intraoperative bleeding and short length of hospital stay.展开更多
Electrical pollution is a worldwide concern,because it is potentially harmful to human health.Trees not only play a significant role in moderating the climate,but also can be used as shields against electrical polluti...Electrical pollution is a worldwide concern,because it is potentially harmful to human health.Trees not only play a significant role in moderating the climate,but also can be used as shields against electrical pollution.Shielding effects on the electric field strength under transmission lines by two tree species,Populus alba and Larix gmelinii,were examined in this study.The electrical resistivity at different heights of trees was measured using a PiCUS sonic tomograph,which can image the electrical impedance for trees.The electric field strength around the trees was measured with an elf field strength measurement system,HI-3604,and combined with tree resistivity to develop a model for calculating the electric field intensity around trees using the finite element method.In addition,the feasibility of the finite element method was confirmed by comparing the calculated results and experimental data.The results showed that the trees did reduce the electric field strength.The electric field intensity was reduced by 95.6%,and P.alba was better than L.gmelinii at shielding.展开更多
Electromagnetic(EM)metamaterials are artificially engineered materials with extraordinary EM properties beyond the limit of existing nat-ural materials;thus,they have been widely used to manipulate the amplitude,phase...Electromagnetic(EM)metamaterials are artificially engineered materials with extraordinary EM properties beyond the limit of existing nat-ural materials;thus,they have been widely used to manipulate the amplitude,phase,polarization,frequency,wave vector,waveform,and other degrees of freedom of EM waves in many practical applications.In this review,we will summarize recent advances in this flourishing field of EM metamateri-als,first from the perspectives of the classical regime and then the quantum regime.More specifically,in the classical regime,traditional EM metamate-rials are based on effective medium theory,and they have limitations of fixed functionalities and an inability to control EM waves in real time.To over-come these restrictions,information metamaterials,including digital coding and field-programmable metamaterials,have recently been proposed to en-able real-time manipulation of EM waves based on the theory of information science.By taking advantage of information metamaterials and artificial in-telligence,another crucial milestone of intelligent metamaterials has been achieved in the development of classical metamaterials.After overviewing EM metamaterials in the classical regime,we discuss cutting-edge studies of EM metamaterials in the quantum regime,namely,topological metamaterials and quantum metamaterials.These nonclassical metamaterials show excellent ability to flexibly manipulate the quantum states,and they extend the clas-sical information metamaterials into the field of quantum information science.At the end of this review,we will give some conclusions and perspectives on this fast-evolving field.展开更多
There is an increasing need to remotely monitor people in daily life using radio-frequency probe signals.However,conventional systems can hardly be deployed in real-world settings since they typically require objects ...There is an increasing need to remotely monitor people in daily life using radio-frequency probe signals.However,conventional systems can hardly be deployed in real-world settings since they typically require objects to either deliberately cooperate or carry a wireless active device or identification tag.To accomplish complicated successive tasks using a single device in real time,we propose the simultaneous use of a smart metasurface imager and recognizer,empowered by a network of artificial neural networks(ANNs)for adaptively controlling data flow.Here,three ANNs are employed in an integrated hierarchy,transforming measured microwave data into images of the whole human body,classifying specifically designated spots(hand and chest)within the whole image,and recognizing human hand signs instantly at a Wi-Fi frequency of 2.4 GHz.Instantaneous in situ full-scene imaging and adaptive recognition of hand signs and vital signs of multiple non-cooperative people were experimentally demonstrated.We also show that the proposed intelligent metasurface system works well even when it is passively excited by stray Wi-Fi signals that ubiquitously exist in our daily lives.The reported strategy could open up a new avenue for future smart cities,smart homes,human-device interaction interfaces,health monitoring,and safety screening free of visual privacy issues.展开更多
Intelligent coding metasurface is a kind of information-carrying metasurface that can manipulate electromagnetic waves and associate digital information simultaneously in a smart way.One of its widely explored applica...Intelligent coding metasurface is a kind of information-carrying metasurface that can manipulate electromagnetic waves and associate digital information simultaneously in a smart way.One of its widely explored applications is to develop advanced schemes of dynamic holographic imaging.By now,the controlling coding sequences of the metasurface are usually designed by performing iterative approaches,including the Gerchberg–Saxton(GS)algorithm and stochastic optimization algorithm,which set a large barrier on the deployment of the intelligent coding metasurface in many practical scenarios with strong demands on high efficiency and capability.Here,we propose an efficient non-iterative algorithm for designing intelligent coding metasurface holograms in the context of unsupervised conditional generative adversarial networks(cGANs),which is referred to as physics-driven variational auto-encoder(VAE)cGAN(VAE-cGAN).Sharply different from the conventional cGAN with a harsh requirement on a large amount of manual-marked training data,the proposed VAE-cGAN behaves in a physics-driving way and thus can fundamentally remove the difficulties in the conventional cGAN.Specifically,the physical operation mechanism between the electric-field distribution and metasurface is introduced to model the VAE decoding module of the developed VAE-cGAN.Selected simulation and experimental results have been provided to demonstrate the state-of-the-art reliability and high efficiency of our VAE-cGAN.It could be faithfully expected that smart holograms could be developed by deploying our VAE-cGAN on neural network chips,finding more valuable applications in communication,microscopy,and so on.展开更多
Epidemiological studies of the COVID-19 patients have suggested the male bias in outcomes of lung illness.To experimentally demonstrate the epidemiological results,we performed animal studies to infect male and female...Epidemiological studies of the COVID-19 patients have suggested the male bias in outcomes of lung illness.To experimentally demonstrate the epidemiological results,we performed animal studies to infect male and female Syrian hamsters with SARS-CoV-2.Remarkably,high viral titer in nasal washings was detectable in male hamsters who presented symptoms of weight loss,weakness,piloerection,hunched back and abdominal respiration,as well as severe pneumonia,pulmonary edema,consolidation,and fibrosis.In contrast with the males,the female hamsters showed much lower shedding viral titers,moderate symptoms,and relatively mild lung pathogenesis.The obvious differences in the susceptibility to SARS-CoV-2 and severity of lung pathogenesis between male and female hamsters provided experimental evidence that SARS-CoV-2 infection and the severity of COVID-19 are associated with gender.展开更多
For camouflage applications,the performance requirements for metamaterials in different electromagnetic spectra are usually contradictory,which makes it difficult to develop satisfactory design schemes with multispect...For camouflage applications,the performance requirements for metamaterials in different electromagnetic spectra are usually contradictory,which makes it difficult to develop satisfactory design schemes with multispectral compatibility.Fortunately,empowered by machine learning,metamaterial design is no longer limited to directly solving Maxwell’s equations.The design schemes and experiences of metamaterials can be analyzed,summarized,and learned by computers,which will significantly improve the design efficiency for the sake of practical engineer-ing applications.Here,we resort to the machine learning to solve the multispectral compatibility problem of metamaterials and demonstrate the design of a new metafilm with multiple mechanisms that can realize small microwave scattering,low infrared emissivity,and visible transparency simultaneously using a multilayer back-propagation neural network.The rapid evolution of structural design is realized by establishing a mapping between spectral curves and structural parameters.By training the network with different materials,the designed network is more adaptable.Through simulations and experimental verifications,the designed architecture has good accuracy and robustness.This paper provides a facile method for fast designs of multispectral metafilms that can find wide applications in satellite solar panels,aircraft windows,and others.展开更多
Varicella-zoster virus(VZV) is a neurotropic alphaherpesvirus that causes chickenpox and shingles. ORF7 is an important virulence determinant of VZV in both human skin and nerve tissues,however, its specific function ...Varicella-zoster virus(VZV) is a neurotropic alphaherpesvirus that causes chickenpox and shingles. ORF7 is an important virulence determinant of VZV in both human skin and nerve tissues,however, its specific function and involved molecular mechanism in VZV pathogenesis remain largely elusive. Previous yeast two-hybrid studies on intraviral protein-protein interaction network in herpesviruses have revealed that VZV ORF7 may interact with ORF53, which is a virtually unstudied but essential viral protein. The aim of this study is to identify and characterize VZV ORF53, and to investigate its relationship with ORF7. For this purpose, we prepared monoclonal antibodies against ORF53 and, for the first time, characterized it as a ~40 k Da viral protein predominantly localizing to the trans-Golgi network of the infected host cell. Next, we further confirmed the interaction between ORF7 and ORF53 by co-immunoprecipitation and co-localization studies in both plasmid-transfected and VZV-infected cells. Moreover, interestingly, we found that ORF53 lost its trans-Golgi network localization and became dispersed in the cytoplasm of host cells infected with an ORF7-deleted recombinant VZV, and thus ORF7 seems to play a role in normal subcellular localization of ORF53. Collectively, these results suggested that ORF7 and ORF53 may function as a complex during infection, which may be implicated in VZV pathogenesis.展开更多
Controlling electromagnetic waves and information simultaneously by information metasurfaces is of central importance in modern society.Intelligent metasurfaces are smart platforms to manipulate the wave-information-m...Controlling electromagnetic waves and information simultaneously by information metasurfaces is of central importance in modern society.Intelligent metasurfaces are smart platforms to manipulate the wave-information-matter interactions without manual intervention by synergizing engineered ultrathin structures with active devices and algorithms,which evolve from the passive composite materials for tailoring wave-matter interactions that cannot be achieved in nature.Here,we review the recent progress of intelligent metasurfaces in wave-information-matter controls by providing the historical background and underlying physical mechanisms.Then we explore the application of intelligent metasurfaces in developing novel wireless communication architectures,with particular emphasis on metasurface-modulated backscatter wireless communications.We also explore the wave-based computing by using the intelligent metasurfaces,focusing on the emerging research direction in intelligent sensing.Finally,we comment on the challenges and highlight the potential routes for the further developments of the intelligent metasurfaces for controls,communications and computing.展开更多
Brain-computer interfaces(BCIs),invasive or non-invasive,have projected unparalleled vision and promise for assisting patients in need to better their interaction with the surroundings.Inspired by the BCI-based rehabi...Brain-computer interfaces(BCIs),invasive or non-invasive,have projected unparalleled vision and promise for assisting patients in need to better their interaction with the surroundings.Inspired by the BCI-based rehabilitation technologies for nerve-system impairments and amputation,we propose an electromagnetic brain-computer-metasurface(EBCM)paradigm,regulated by human’s cognition by brain signals directly and non-invasively.We experimentally show that our EBCM platform can translate human’s mind from evoked potentials of P300-based electroencephalography to digital coding information in the electromagnetic domain non-invasively,which can be further processed and transported by an information metasurface in automated and wireless fashions.Directly wireless communications of the human minds are performed between two EBCM operators with accurate text transmissions.Moreover,several other proof-of-concept mind-control schemes are presented using the same EBCM platform,exhibiting flexibly-customized capabilities of information processing and synthesis like visual-beam scanning,wave modulations,and pattern encoding.展开更多
Metamaterials and metasurfaces have inspired worldwide interest in the recent two decades due to their extraordinary performance in controlling material parameters and electromagnetic properties.However,most studies o...Metamaterials and metasurfaces have inspired worldwide interest in the recent two decades due to their extraordinary performance in controlling material parameters and electromagnetic properties.However,most studies on metamaterials and metasurfaces are focused on manipulations of electromagnetic fields and waves,because of their analog natures.The concepts of digital coding and programmable metasurfaces proposed in 2014 have opened a new perspective to characterize and design metasurfaces in a digital way,and made it possible to control electromagnetic fields/waves and process digital information simultaneously,yielding the birth of a new direction of information metasurfaces.On the other hand,artificial intelligence(AI)has become more important in automatic designs of metasurfaces.In this review paper,we first show the intrinsic natures and advantages of information metasurfaces,including information operations,programmable and real-time control capabilities,and space–time-coding strategies.Then we introduce the recent advances in designing metasurfaces using AI technologies,and particularly discuss the close combinations of information metasurfaces and AI to generate intelligent metasurfaces.We present self-adaptively smart metasurfaces,AI-based intelligent imagers,microwave cameras,and programmable AI machines based on optical neural networks.Finally,we indicate the challenges,applications,and future directions of information and intelligent metasurfaces.展开更多
A 59-year-old female patient was admitted to our center complaining of upper abdominal pain,fatigue,and intermittent fever for the past 4 months.Her cancer antigen 125(CA125)level was 143.8 U/mL.The computed tomograph...A 59-year-old female patient was admitted to our center complaining of upper abdominal pain,fatigue,and intermittent fever for the past 4 months.Her cancer antigen 125(CA125)level was 143.8 U/mL.The computed tomography(CT)scan showed multiple low-density foci in the liver with arterial enhancement,suggestive of liver metastases(Figure 1A).Meanwhile,the positron emission tomography(PET)/CT scan demonstrated multiple FDG avid lesions in the liver with multiple enlarged lymph nodes in the left supraclavicular,mediastinal,supradiaphragmatic,hilar,and retroperitoneal regions,suggestive of liver and lymph nodal metastases(Figure 1B).展开更多
文摘Background:The high incidence of gallstone recurrence was a major concern for laparoscopic gallbladderpreserving surgery.This study aimed to investigate the risk factors for gallstone recurrence after gallbladder-preserving surgery and to establish an individualized nomogram model to predict the risk of gallstone recurrence.Methods:The clinicopathological and follow-up data of 183 patients who were initially diagnosed with gallstones and treated with gallbladder-preserving surgery at our hospital from January 2012 to January 2019 were retrospectively collected.The independent predictive factors for gallstone recurrence following gallbladder-preserving surgery were identified by multivariate logistic regression analysis.A nomogram model for the prediction of gallstone recurrence was constructed based on the selected variables.The C-index,receiver operating characteristic(ROC)curve and calibration curve were used to evaluate the predictive power of the nomogram model for gallstone recurrence.Results:During the follow-up period,a total of 65 patients experienced gallstone recurrence,and the recurrence rate was 35.5%.Multivariate logistic regression analysis revealed that the course of gallstones>2 years[odds ratio(OR)=2.567,95%confidence interval(CI):1.270-5.187,P=0.009],symptomatic gallstones(OR=2.589,95%CI:1.059-6.329,P=0.037),multiple gallstones(OR=2.436,95%CI:1.133-5.237,P=0.023),history of acute cholecystitis(OR=2.778,95%CI:1.178-6.549,P=0.020)and a greasy diet(OR=2.319,95%CI:1.186-4.535,P=0.014)were independent risk factors for gallstone recurrence after gallbladder-preserving surgery.A nomogram model for predicting the recurrence of gallstones was established based on the above five variables.The results showed that the C-index of the nomogram model was 0.692,suggesting it was valuable to predict gallstone recurrence.Moreover,the calibration curve showed good consistency between the predicted probability and actual probability.Conclusions:The nomogram model for the prediction of gallstone recurrence might help clinicians develop a proper treatment strategy for patients with gallstones.Gallbladder-preserving surgery should be cautiously considered for patients with high recurrence risks.
基金the support of the Leverhulme Centre for Wildfires,Environment and Society through the Leverhulme Trust(RC-2018-023)Sibo Cheng,César Quilodran-Casas,and Rossella Arcucci acknowledge the support of the PREMIERE project(EP/T000414/1)+5 种基金the support of EPSRC grant:PURIFY(EP/V000756/1)the Fundamental Research Funds for the Central Universitiesthe support of the SASIP project(353)funded by Schmidt Futures–a philanthropic initiative that seeks to improve societal outcomes through the development of emerging science and technologiesDFG for the Heisenberg Programm Award(JA 1077/4-1)the National Natural Science Foundation of China(61976120)the Natural Science Key Foundat ion of Jiangsu Education Department(21KJA510004)。
文摘Data assimilation(DA)and uncertainty quantification(UQ)are extensively used in analysing and reducing error propagation in high-dimensional spatial-temporal dynamics.Typical applications span from computational fluid dynamics(CFD)to geoscience and climate systems.Recently,much effort has been given in combining DA,UQ and machine learning(ML)techniques.These research efforts seek to address some critical challenges in high-dimensional dynamical systems,including but not limited to dynamical system identification,reduced order surrogate modelling,error covariance specification and model error correction.A large number of developed techniques and methodologies exhibit a broad applicability across numerous domains,resulting in the necessity for a comprehensive guide.This paper provides the first overview of state-of-the-art researches in this interdisciplinary field,covering a wide range of applications.This review is aimed at ML scientists who attempt to apply DA and UQ techniques to improve the accuracy and the interpretability of their models,but also at DA and UQ experts who intend to integrate cutting-edge ML approaches to their systems.Therefore,this article has a special focus on how ML methods can overcome the existing limits of DA and UQ,and vice versa.Some exciting perspectives of this rapidly developing research field are also discussed.Index Terms-Data assimilation(DA),deep learning,machine learning(ML),reduced-order-modelling,uncertainty quantification(UQ).
文摘BACKGROUND B-mode-ultrasound-guided percutaneous cholecystostomy(PC)may be performed by a transhepatic or transperitoneal approach,called percutaneous transhepatic gallbladder drainage(PHGD)and percutaneous transperitoneal gallbladder drainage(PPGD),respectively.We compared the impact of PC related to the route of catheter placement on subsequent laparoscopic cholecystectomy(LC).AIM To compare the impact of PC related to the route of catheter placement on subsequent LC.METHODS We retrospectively studied 103 patients with acute calculous cholecystitis who underwent scheduled LC after PC between January 2010 and January 2019.Group I included 58 patients who underwent scheduled LC after PHGD.Group II included 45 patients who underwent scheduled LC after PPGD.Clinical outcomes were analyzed according to each group.RESULTS Baseline demographic characteristics did not differ significantly between both groups(P>0.05).Both PHGD and PPGD were able to quickly resolve cholecystitis sepsis.Group I showed significantly higher efficacy than group II in terms of lower pain score during puncture(3.1 vs 4.5;P=0.001)and at 12 h follow-up(1.5 vs 2.2;P=0.001),lower rate of fever within 24 h after PC(13.8%vs 42.2%;P=0.001),shorted operation duration(118.3 vs 139.6 min;P=0.001),lower amount of intraoperative bleeding(72.1 vs 109.4 mL;P=0.001)and shorter length of hospital stay(14.3 d vs 18.0 d;P=0.001).However,group II had significantly lower rate of local bleeding at the PC site(2.2%vs 20.7%;P=0.005)and lower rate of severe adhesion(33.5%vs 55.2%;P=0.048).No significant differences were noted between both groups regarding the conversion rate to laparotomy,rate of subtotal cholecystectomy,complications and pathology.CONCLUSION B-mode-ultrasound-guided PHGD is superior to PPGD followed by LC for treatment of acute calculous cholecystitis,with shorter operating time,minimal amount of intraoperative bleeding and short length of hospital stay.
基金financially supported by the National Key Research and Development Program(2017YFD0600101)the Central University Basic Research and Operating Expenses of Special Funding(2572016CB04)the Harbin Application Technology Research and Development Projects(2016RQQXJ134)
文摘Electrical pollution is a worldwide concern,because it is potentially harmful to human health.Trees not only play a significant role in moderating the climate,but also can be used as shields against electrical pollution.Shielding effects on the electric field strength under transmission lines by two tree species,Populus alba and Larix gmelinii,were examined in this study.The electrical resistivity at different heights of trees was measured using a PiCUS sonic tomograph,which can image the electrical impedance for trees.The electric field strength around the trees was measured with an elf field strength measurement system,HI-3604,and combined with tree resistivity to develop a model for calculating the electric field intensity around trees using the finite element method.In addition,the feasibility of the finite element method was confirmed by comparing the calculated results and experimental data.The results showed that the trees did reduce the electric field strength.The electric field intensity was reduced by 95.6%,and P.alba was better than L.gmelinii at shielding.
基金supported by the National Natural Science Foundation of China(Grant Nos.62201136,62175215,62101124,and 62288101)National Key Research and Development Program of China(Grant Nos.2017YFA0700201,2017YFA0700202,and 2017YFA0700203)+1 种基金the Natural Science Foundation of Jiangsu Province(Grant Nos.BK20210209,BK20212002,and BK20220808)111 Project(Grant No.111-2-05).
文摘Electromagnetic(EM)metamaterials are artificially engineered materials with extraordinary EM properties beyond the limit of existing nat-ural materials;thus,they have been widely used to manipulate the amplitude,phase,polarization,frequency,wave vector,waveform,and other degrees of freedom of EM waves in many practical applications.In this review,we will summarize recent advances in this flourishing field of EM metamateri-als,first from the perspectives of the classical regime and then the quantum regime.More specifically,in the classical regime,traditional EM metamate-rials are based on effective medium theory,and they have limitations of fixed functionalities and an inability to control EM waves in real time.To over-come these restrictions,information metamaterials,including digital coding and field-programmable metamaterials,have recently been proposed to en-able real-time manipulation of EM waves based on the theory of information science.By taking advantage of information metamaterials and artificial in-telligence,another crucial milestone of intelligent metamaterials has been achieved in the development of classical metamaterials.After overviewing EM metamaterials in the classical regime,we discuss cutting-edge studies of EM metamaterials in the quantum regime,namely,topological metamaterials and quantum metamaterials.These nonclassical metamaterials show excellent ability to flexibly manipulate the quantum states,and they extend the clas-sical information metamaterials into the field of quantum information science.At the end of this review,we will give some conclusions and perspectives on this fast-evolving field.
基金supported by the National Key Research and Development Program of China under Grant Nos.2017YFA0700201,2017YFA0700202,and 2017YFA0700203the National Natural Science Foundation of China under Grant Nos.61471006,61631007,and 61571117the 111 Project under Grant No.111-2-05.
文摘There is an increasing need to remotely monitor people in daily life using radio-frequency probe signals.However,conventional systems can hardly be deployed in real-world settings since they typically require objects to either deliberately cooperate or carry a wireless active device or identification tag.To accomplish complicated successive tasks using a single device in real time,we propose the simultaneous use of a smart metasurface imager and recognizer,empowered by a network of artificial neural networks(ANNs)for adaptively controlling data flow.Here,three ANNs are employed in an integrated hierarchy,transforming measured microwave data into images of the whole human body,classifying specifically designated spots(hand and chest)within the whole image,and recognizing human hand signs instantly at a Wi-Fi frequency of 2.4 GHz.Instantaneous in situ full-scene imaging and adaptive recognition of hand signs and vital signs of multiple non-cooperative people were experimentally demonstrated.We also show that the proposed intelligent metasurface system works well even when it is passively excited by stray Wi-Fi signals that ubiquitously exist in our daily lives.The reported strategy could open up a new avenue for future smart cities,smart homes,human-device interaction interfaces,health monitoring,and safety screening free of visual privacy issues.
基金National Key Research and Development Program of China(2017YFA0700201,2017YFA0700202,2017YFA0700203,2018YFA0701900).
文摘Intelligent coding metasurface is a kind of information-carrying metasurface that can manipulate electromagnetic waves and associate digital information simultaneously in a smart way.One of its widely explored applications is to develop advanced schemes of dynamic holographic imaging.By now,the controlling coding sequences of the metasurface are usually designed by performing iterative approaches,including the Gerchberg–Saxton(GS)algorithm and stochastic optimization algorithm,which set a large barrier on the deployment of the intelligent coding metasurface in many practical scenarios with strong demands on high efficiency and capability.Here,we propose an efficient non-iterative algorithm for designing intelligent coding metasurface holograms in the context of unsupervised conditional generative adversarial networks(cGANs),which is referred to as physics-driven variational auto-encoder(VAE)cGAN(VAE-cGAN).Sharply different from the conventional cGAN with a harsh requirement on a large amount of manual-marked training data,the proposed VAE-cGAN behaves in a physics-driving way and thus can fundamentally remove the difficulties in the conventional cGAN.Specifically,the physical operation mechanism between the electric-field distribution and metasurface is introduced to model the VAE decoding module of the developed VAE-cGAN.Selected simulation and experimental results have been provided to demonstrate the state-of-the-art reliability and high efficiency of our VAE-cGAN.It could be faithfully expected that smart holograms could be developed by deploying our VAE-cGAN on neural network chips,finding more valuable applications in communication,microscopy,and so on.
基金This work was supported by grants from the National Science and Technology Major Project of Infectious Diseases(No.2017ZX10304402-002-003)the National Science and Technology Major Projects for Major New Drugs Innovation and Development(No.2018ZX09711003-005-003)+2 种基金the Science and Technology Project of Fujian Province(2020YZ014001)the Science and Technology Project of Xiamen City(3502Z2020YJ01)the CAMS Innovation Fund for Medical Sciences(No.2019RU022).
文摘Epidemiological studies of the COVID-19 patients have suggested the male bias in outcomes of lung illness.To experimentally demonstrate the epidemiological results,we performed animal studies to infect male and female Syrian hamsters with SARS-CoV-2.Remarkably,high viral titer in nasal washings was detectable in male hamsters who presented symptoms of weight loss,weakness,piloerection,hunched back and abdominal respiration,as well as severe pneumonia,pulmonary edema,consolidation,and fibrosis.In contrast with the males,the female hamsters showed much lower shedding viral titers,moderate symptoms,and relatively mild lung pathogenesis.The obvious differences in the susceptibility to SARS-CoV-2 and severity of lung pathogenesis between male and female hamsters provided experimental evidence that SARS-CoV-2 infection and the severity of COVID-19 are associated with gender.
基金Natural Science Basic Research Program of Shaanxi Province(2020JQ-471,2020JQ-472)National Key Research and Development Program of China(SQ2017YFA0700201)National Natural Science Foundation of China(12004437,51802349,61971435).
文摘For camouflage applications,the performance requirements for metamaterials in different electromagnetic spectra are usually contradictory,which makes it difficult to develop satisfactory design schemes with multispectral compatibility.Fortunately,empowered by machine learning,metamaterial design is no longer limited to directly solving Maxwell’s equations.The design schemes and experiences of metamaterials can be analyzed,summarized,and learned by computers,which will significantly improve the design efficiency for the sake of practical engineer-ing applications.Here,we resort to the machine learning to solve the multispectral compatibility problem of metamaterials and demonstrate the design of a new metafilm with multiple mechanisms that can realize small microwave scattering,low infrared emissivity,and visible transparency simultaneously using a multilayer back-propagation neural network.The rapid evolution of structural design is realized by establishing a mapping between spectral curves and structural parameters.By training the network with different materials,the designed network is more adaptable.Through simulations and experimental verifications,the designed architecture has good accuracy and robustness.This paper provides a facile method for fast designs of multispectral metafilms that can find wide applications in satellite solar panels,aircraft windows,and others.
基金supported by the National Natural Science Foundation of China (No. 81601762)the National Science and Technology Major Project of Infectious Diseases (No. 2017ZX10304402)+1 种基金the National Science and Technology Major Projects for Major New Drugs Innovation and Development (No. 2017ZX09101005-005-003)the Scientific Research Foundation of State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics (No. 2016ZY005)
文摘Varicella-zoster virus(VZV) is a neurotropic alphaherpesvirus that causes chickenpox and shingles. ORF7 is an important virulence determinant of VZV in both human skin and nerve tissues,however, its specific function and involved molecular mechanism in VZV pathogenesis remain largely elusive. Previous yeast two-hybrid studies on intraviral protein-protein interaction network in herpesviruses have revealed that VZV ORF7 may interact with ORF53, which is a virtually unstudied but essential viral protein. The aim of this study is to identify and characterize VZV ORF53, and to investigate its relationship with ORF7. For this purpose, we prepared monoclonal antibodies against ORF53 and, for the first time, characterized it as a ~40 k Da viral protein predominantly localizing to the trans-Golgi network of the infected host cell. Next, we further confirmed the interaction between ORF7 and ORF53 by co-immunoprecipitation and co-localization studies in both plasmid-transfected and VZV-infected cells. Moreover, interestingly, we found that ORF53 lost its trans-Golgi network localization and became dispersed in the cytoplasm of host cells infected with an ORF7-deleted recombinant VZV, and thus ORF7 seems to play a role in normal subcellular localization of ORF53. Collectively, these results suggested that ORF7 and ORF53 may function as a complex during infection, which may be implicated in VZV pathogenesis.
基金National Key Research and Development Program of China under Grant Nos.2021YFA1401002,2017YFA0700201,2017YFA0700202,and 2017YFA0700203,and the 111 Project under Grant No.111-2-05.
文摘Controlling electromagnetic waves and information simultaneously by information metasurfaces is of central importance in modern society.Intelligent metasurfaces are smart platforms to manipulate the wave-information-matter interactions without manual intervention by synergizing engineered ultrathin structures with active devices and algorithms,which evolve from the passive composite materials for tailoring wave-matter interactions that cannot be achieved in nature.Here,we review the recent progress of intelligent metasurfaces in wave-information-matter controls by providing the historical background and underlying physical mechanisms.Then we explore the application of intelligent metasurfaces in developing novel wireless communication architectures,with particular emphasis on metasurface-modulated backscatter wireless communications.We also explore the wave-based computing by using the intelligent metasurfaces,focusing on the emerging research direction in intelligent sensing.Finally,we comment on the challenges and highlight the potential routes for the further developments of the intelligent metasurfaces for controls,communications and computing.
基金National Key Research and Development Program of China(2017YFA0700201,2017YFA0700202,and 2017YFA0700203)Major Project of Natural Science Foundation of Jiangsu Province(BK20212002)+9 种基金National Natural Science Foundation of China(61871127,61735010,61731010,61890544,61801117,61722106,61701107,61701108,61701246,61631007,61633010,61876064,62076099,61731010,and 11874142)State Key Laboratory of Millimeter Waves,Southeast University,China(K201924)Fundamental Research Funds for the Central Universities(2242018R30001)111 Project(111-2-05)Fund for International Cooperation and Exchange of National Natural Science Foundation of China(61761136007)Key R&D Program of Guangdong Province(2018B030339001)Key Realm R&D Program of Guangzhou(202007030007)Guangdong Basic and Applied Basic Research Foundation(2019A1515011773)Pearl River S&T Nova Program of Guangzhou(201906010043)C.-W.Q.acknowledges the financial support from the grant R-261-518-004-720 from Advanced Research and Technology Innovation Centre(ARTIC)。
文摘Brain-computer interfaces(BCIs),invasive or non-invasive,have projected unparalleled vision and promise for assisting patients in need to better their interaction with the surroundings.Inspired by the BCI-based rehabilitation technologies for nerve-system impairments and amputation,we propose an electromagnetic brain-computer-metasurface(EBCM)paradigm,regulated by human’s cognition by brain signals directly and non-invasively.We experimentally show that our EBCM platform can translate human’s mind from evoked potentials of P300-based electroencephalography to digital coding information in the electromagnetic domain non-invasively,which can be further processed and transported by an information metasurface in automated and wireless fashions.Directly wireless communications of the human minds are performed between two EBCM operators with accurate text transmissions.Moreover,several other proof-of-concept mind-control schemes are presented using the same EBCM platform,exhibiting flexibly-customized capabilities of information processing and synthesis like visual-beam scanning,wave modulations,and pattern encoding.
基金the National Key Research and Development Program of China(2017YFA0700201,2017YFA0700202,and 2017YFA0700203)the Major Project of Natural Science Foundation of Jiangsu Province(BK20212002)+4 种基金the National Natural Science Foundation of China(61871127,61735010,61731010,61890544,61801117,61722106,61701107,61701108,61701246,and 61631007)the State Key Laboratory of Millimeter Waves,Southeast University,China(K201924),the Fundamental Research Funds for the Central Universities(2242022R20017)the 111 Project(111-2-05)the Fund for International Cooperation and Exchange of the National Natural Science Foundation of China(61761136007)the China Postdoctoral Science Foundation(2021M700761).
文摘Metamaterials and metasurfaces have inspired worldwide interest in the recent two decades due to their extraordinary performance in controlling material parameters and electromagnetic properties.However,most studies on metamaterials and metasurfaces are focused on manipulations of electromagnetic fields and waves,because of their analog natures.The concepts of digital coding and programmable metasurfaces proposed in 2014 have opened a new perspective to characterize and design metasurfaces in a digital way,and made it possible to control electromagnetic fields/waves and process digital information simultaneously,yielding the birth of a new direction of information metasurfaces.On the other hand,artificial intelligence(AI)has become more important in automatic designs of metasurfaces.In this review paper,we first show the intrinsic natures and advantages of information metasurfaces,including information operations,programmable and real-time control capabilities,and space–time-coding strategies.Then we introduce the recent advances in designing metasurfaces using AI technologies,and particularly discuss the close combinations of information metasurfaces and AI to generate intelligent metasurfaces.We present self-adaptively smart metasurfaces,AI-based intelligent imagers,microwave cameras,and programmable AI machines based on optical neural networks.Finally,we indicate the challenges,applications,and future directions of information and intelligent metasurfaces.
文摘A 59-year-old female patient was admitted to our center complaining of upper abdominal pain,fatigue,and intermittent fever for the past 4 months.Her cancer antigen 125(CA125)level was 143.8 U/mL.The computed tomography(CT)scan showed multiple low-density foci in the liver with arterial enhancement,suggestive of liver metastases(Figure 1A).Meanwhile,the positron emission tomography(PET)/CT scan demonstrated multiple FDG avid lesions in the liver with multiple enlarged lymph nodes in the left supraclavicular,mediastinal,supradiaphragmatic,hilar,and retroperitoneal regions,suggestive of liver and lymph nodal metastases(Figure 1B).
