There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESⅢ and B fac...There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESⅢ and B factories, and the observation of an intriguing proton-antiproton threshold enhancement and the possibly related X(1835) meson state at BESⅢ, as well as the threshold measurements of charm mesons and charm baryons. We present a detailed survey of the important topics in tau-charm physics and hadron physics that can be further explored at BESⅢ during the remaining operation period of BEPCⅡ. This survey will help in the optimization of the data-taking plan over the coming years, and provides physics motivation for the possible upgrade of BEPCⅡ to higher luminosity.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
To explore the effect of early enteral nutrition （EN） on postoperative nutritional status, intestinal permeability, and immune 6anction in elderly patients with esophageal cancer or cardiac cancer. Methods： A total...To explore the effect of early enteral nutrition （EN） on postoperative nutritional status, intestinal permeability, and immune 6anction in elderly patients with esophageal cancer or cardiac cancer. Methods： A total of 96 patients with esophageal cancer or cardiac cancer who underwent surgical treatment in our hospital from June 2007 to December 2010 were enrolled in this study. They were divided into EN group （n=50） and parenteral nutrition （PN） group （n=46） based on the nutrition support modes. The body weight, time to first flatus/defecation, average hospital stay, complications and mortality after the surgery as well as the liver function indicators were recorded and analyzed. Peripheral blood samples were collected on the days 1, 4 and 7 after surgery. The plasma diamine oxidase （DAO） activity and D-lactate level were determined to assess the intestinal permeability. The plasma endotoxin levels were determined using dynamic turbidimetric assay to assess the protective effect of EN on intestinal mucosal barrier. The postoperative blood levels of inflammatory cytokines and immunoglobulins were determined using enzyme- linked immunosorbent assay （ELISA）. Results： After the surgery, the time to first flatus/defecation, average hospital stay, and complications were significantly less in the EN group than those in the PN group （P〈0.05）, whereas the EN group had significantly higher albumin levels than the PN group （P〈0.05）. On the 7th postoperative day, the DAO activity, D-lactate level and endotoxin contents were significantly lower in the EN group than those in the PN group （all P〈0.05）. In addition, the EN group had significantly higher IgA, IgG, IgM, and CD4 levels than the PN group （P〈0.05） but significantly lower IL-2, IL-6, and TNF-a levels （P〈0.05）. Conclusions： In elderly patients with esophageal cancer or cardiac cancer, early EN after surgery can effectively improve the nutritional status, protect intestinal mucosal barrier （by reducing plasma展开更多
Tissue engineering has become a promising strategy for repairing damaged cartilage and bone tissue. Among the scaffolds for tissue-engineering applications, injectable hydrogels have demonstrated great potential for u...Tissue engineering has become a promising strategy for repairing damaged cartilage and bone tissue. Among the scaffolds for tissue-engineering applications, injectable hydrogels have demonstrated great potential for use as three-dimensional cell culture scaffolds in cartilage and bone tissue engineering, owing to their high water content, similarity to the natural extracellular matrix(ECM), porous framework for cell transplantation and proliferation, minimal invasive properties, and ability to match irregular defects. In this review, we describe the selection of appropriate biomaterials and fabrication methods to prepare novel injectable hydrogels for cartilage and bone tissue engineering. In addition, the biology of cartilage and the bony ECM is also summarized. Finally, future perspectives for injectable hydrogels in cartilage and bone tissue engineering are discussed.展开更多
Four wetland maps for all China have been produced,based on Landsat and CBERS-02B remote sensing data between 1978 and 2008 (1978,1990,2000 and 2008).These maps were mainly developed by manual interpretation and valid...Four wetland maps for all China have been produced,based on Landsat and CBERS-02B remote sensing data between 1978 and 2008 (1978,1990,2000 and 2008).These maps were mainly developed by manual interpretation and validated by substantial field investigation in 2009.Based on these maps,we analyzed the 2008 wetland distribution in China and discussed wetland changes and their drivers over the past 30 years.(i) There were about 324097 km 2 of wetlands in 2008,for which inland marshes or swamps were the most common wetland type (35%),with lakes (26%) second.Most of the wetlands were in Heilongjiang,Inner Mongolia,Qinghai and Tibet,occupying about 55% of the national wetland area.(ii) From 1978 to 2008,China's wetland area continually and significantly decreased,by about 33% based on changes in the wetland map.This was in sharp contrast to the increase in artificial wetlands,which increased by about 122%.Inland marshes accounted for the main loss of total wetlands from 1978 to 2000.From 2000 through 2008,riverine and lacustrine wetlands constituted the main wetland loss.Fortunately however,the rate of wetland loss decreased from 5523 to 831 km 2 /a.(iii) The change ratio of lost natural wetlands (including inland and coastal wetlands) to non-wetlands has decreased slightly over the past 30 years.From 1978 to 1990,nearly all natural wetlands (98%) lost were transformed into non-wetlands.However,the ratio declined to 86% from 1990 to 2000,and to 77% from 2000 to 2008.(iv) All Chinese provinces were divided into three groups according to patterns of wetland changes,which could relate to the driving forces of such changes.Tibet was completely different from other provinces,as it was one representative example in which there was a net wetland increase,because of global warming and decreased human activity since 1990.Increased economic development caused considerable wetland loss in most eastern provinces,and artificial wetlands increased.展开更多
Machine learning(ML) has been widely applied to the upper layers of wireless communication systems for various purposes, such as deployment of cognitive radio and communication network. However, its application to the...Machine learning(ML) has been widely applied to the upper layers of wireless communication systems for various purposes, such as deployment of cognitive radio and communication network. However, its application to the physical layer is hampered by sophisticated channel environments and limited learning ability of conventional ML algorithms. Deep learning(DL) has been recently applied for many fields, such as computer vision and natural language processing, given its expressive capacity and convenient optimization capability. The potential application of DL to the physical layer has also been increasingly recognized because of the new features for future communications, such as complex scenarios with unknown channel models, high speed and accurate processing requirements; these features challenge conventional communication theories. This paper presents a comprehensive overview of the emerging studies on DL-based physical layer processing, including leveraging DL to redesign a module of the conventional communication system(for modulation recognition, channel decoding, and detection) and replace the communication system with a radically new architecture based on an autoencoder. These DL-based methods show promising performance improvements but have certain limitations, such as lack of solid analytical tools and use of architectures that are specifically designed for communication and implementation research, thereby motivating future research in this field.展开更多
There is considerable potential for integrating transarterial chemoembolization(TACE),programmed death-(ligand)1(PD-[L]1)inhibitors,and molecular targeted treatments(MTT)in hepatocellular carcinoma(HCC).It is necessar...There is considerable potential for integrating transarterial chemoembolization(TACE),programmed death-(ligand)1(PD-[L]1)inhibitors,and molecular targeted treatments(MTT)in hepatocellular carcinoma(HCC).It is necessary to investigate the therapeutic efficacy and safety of TACE combined with PD-(L)1 inhibitors and MTT in real-world situations.In this nationwide,retrospective,cohort study,826 HCC patients receiving either TACE plus PD-(L)1 blockades and MTT(combination group,n=376)or TACE monotherapy(monotherapy group,n=450)were included from January 2018 to May 2021.The primary endpoint was progression-free survival(PFS)according to modified RECIST.The secondary outcomes included overall survival(OS),objective response rate(ORR),and safety.We performed propensity score matching approaches to reduce bias between two groups.After matching,228 pairs were included with a predominantly advanced disease population.Median PFS in combination group was 9.5 months(95%confidence interval[CI],8.4-11.0)versus 8.0 months(95%CI,6.6-9.5)(adjusted hazard ratio[HR],0.70,P=0.002).OS and ORR were also significantly higher in combination group(median OS,19.2[16.1-27.3]vs.15.7 months[13.0-20.2];adjusted HR,0.63,P=0.001;ORR,60.1%vs.32.0%;P<0.001).Grade 3/4 adverse events were observed at a rate of 15.8%and 7.5%in combination and monotherapy groups,respectively.Our results suggest that TACE plus PD-(L)1 blockades and MTT could significantly improve PFS,OS,and ORR versus TACE monotherapy for Chinese patients with predominantly advanced HCC in real-world practice,with an acceptable safety profile.展开更多
Soil salinization is one of the most common land degradation processes. In this study, spectral measurements of saline soil samples collected from the Yellow River Delta region of China were conducted in laboratory an...Soil salinization is one of the most common land degradation processes. In this study, spectral measurements of saline soil samples collected from the Yellow River Delta region of China were conducted in laboratory and hyperspectral data were acquired from an EO-1 Hyperion sensor to quantitatively map soil salinity in the region. A soil salinity spectral index (SSI) was constructed from continuum-removed reflectance (CR-reflectance) at 2052 and 2203 nm, to analyze the spectral absorption features of the salt-affected soils. There existed a strong correlation (r = 0.91) between the SSI and soil salt content (SSC). Then, a model for estimation of SSC with SSI was established using univariate regression and validation of the model yielded a root mean square error (RMSE) of 0.986 and an R2 of 0.873. The model was applied to a Hyperion reflectance image on a pixel-by-pixel basis and the resulting quantitative salinity map was validated successfully with RMSE = 1.921 and R2 = 0.627. These suggested that the satellite hyperspectral data had the potential for predicting SSC in a large area.展开更多
To review the rockburst proneness(or tendency)criteria of rock materials and compare the judgment accuracy of them,twenty criteria were summarized,and their judgment accuracy was evaluated and compared based on the la...To review the rockburst proneness(or tendency)criteria of rock materials and compare the judgment accuracy of them,twenty criteria were summarized,and their judgment accuracy was evaluated and compared based on the laboratory tests on fourteen types of rocks.This study begins firstly by introducing the twenty rockburst proneness criteria,and their origins,definitions,calculation methods and grading standards were summarized in detail.Subsequently,to evaluate and compare the judgment accuracy of the twenty criteria,a series of laboratory tests were carried out on fourteen types of rocks,and the rockburst proneness judgment results of the twenty criteria for the fourteen types of rocks were obtained accordingly.Moreover,to provide a unified basis for the judgment accuracy evaluation of above criteria,a classification standard(obtained according to the actual failure results and phenomena of rock specimen)of rockburst proneness in laboratory tests was introduced.The judgment results of the twenty criteria were compared with the judgment results of this classification standard.The results show that the judgment results of the criterion based on residual elastic energy(REE)index are completely consistent with the actual rockburst proneness,and the other criteria have some inconsistent situations more or less.Moreover,the REE index is based on the linear energy storage law and defined in form of a difference value and considered the whole failure process,and these superior characteristics ensure its accuracy.It is believed that the criterion based on REE index is comparatively more accurate and scientific than other criteria,and it can be recommended to be applied to judge the rockburst proneness of rock materials.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
Intelligence at either the material or metamaterial level is a goal that researchers have been pursuing.From passive to active,metasurfaces have been developed to be programmable to dynamically and arbitrarily manipul...Intelligence at either the material or metamaterial level is a goal that researchers have been pursuing.From passive to active,metasurfaces have been developed to be programmable to dynamically and arbitrarily manipulate electromagnetic(EM)wavefields.However,the programmable metasurfaces require manual control to switch among different functionalities.Here,we put forth a smart metasurface that has self-adaptively reprogrammable functionalities without human participation.The smart metasurface is capable of sensing ambient environments by integrating an additional sensor(s)and can adaptively adjust its EM operational functionality through an unmanned sensing feedback system.As an illustrative example,we experimentally develop a motion-sensitive smart metasurface integrated with a three-axis gyroscope,which can adjust self-adaptively the EM radiation beams via different rotations of the metasurface.We develop an online feedback algorithm as the control software to make the smart metasurface achieve single-beam and multibeam steering and other dynamic reactions adaptively.The proposed metasurface is extendable to other physical sensors to detect the humidity,temperature,illuminating light,and so on.Our strategy will open up a new avenue for future unmanned devices that are consistent with the ambient environment.展开更多
A patch with the capability of avoiding wound infection and promoting tissue remolding is of great value for wound healing.In this paper,we develop a biomass chitosan microneedle array(CSMNA)patch integrated with smar...A patch with the capability of avoiding wound infection and promoting tissue remolding is of great value for wound healing.In this paper,we develop a biomass chitosan microneedle array(CSMNA)patch integrated with smart responsive drug delivery for promoting wound healing.Chitosan possesses many outstanding features such as the natural antibacterial property and has been widely utilized for wound healing.Besides,the microstructure of microneedles enables the effective delivery of loaded drugs into the target area and avoids the excessive adhesion between the skin and the patch.Also,vascular endothelial growth factor(VEGF)is encapsulated in the micropores of CSMNA by temperature sensitive hydrogel.Therefore,the smart release of the drugs can be controllably realized via the temperature rising induced by the inflammation response at the site of wounds.It is demonstrated that the biomass CSMNA patch can promote inflammatory inhibition,collagen deposition,angiogenesis,and tissue regeneration during the wound closure.Thus,this versatile CSMNA patch is potentially valuable for wound healing in clinical applications.展开更多
The terahertz region is a special region of the electromagnetic spectrum that incorporates the advantages of both microwaves and infrared light waves.In the past decade,metamaterials with effective medium parameters o...The terahertz region is a special region of the electromagnetic spectrum that incorporates the advantages of both microwaves and infrared light waves.In the past decade,metamaterials with effective medium parameters or gradient phases have been studied to control terahertz waves and realize functional devices.Here,we present a new approach to manipulate terahertz waves by using coding metasurfaces that are composed of digital coding elements.We propose a general coding unit based on a Minkowski closed-loop particle that is capable of generating 1-bit coding(with two phase states of 0 and 180°),2-bit coding(with four phase states of 0,90°,180°,and 270°),and multi-bit coding elements in the terahertz frequencies by using different geometric scales.We show that multi-bit coding metasurfaces have strong abilities to control terahertz waves by designing-specific coding sequences.As an application,we demonstrate a new scattering strategy of terahertz waves—broadband and wide-angle diffusion—using a 2-bit coding metasurface with a special coding design and verify it by both numerical simulations and experiments.The presented method opens a new route to reducing the scattering of terahertz waves.展开更多
There have been continuous efforts to seek novel functional two-dimensional semiconductors with high performance for future applications in nanoelectronics and optoelectronics. In this work, we introduce a successful ...There have been continuous efforts to seek novel functional two-dimensional semiconductors with high performance for future applications in nanoelectronics and optoelectronics. In this work, we introduce a successful experimental approach to fabricate monolayer phosphorene by mechanical cleavage and a subsequent Ar＊ plasma thinning process. The thickness of phosphorene is unambiguously determined by optical contrast spectra combined with atomic force microscopy （AFM）. Raman spectroscopy is used to characterize the pristine and plasma-treated samples. The Raman frequency of the A2g mode stiffens, and the intensity ratio of A2g to Alg modes shows a monotonic discrete increase with the decrease of phosphorene thickness down to a monolayer. All those phenomena can be used to identify the thickness of this novel two-dimensional semiconductor. This work on monolayer phosphorene fabrication and thickness determination will facilitate future research on phosphorene.展开更多
BACKGROUND:Contrast agents help to improve visibility in magnetic resonance(MR)imaging.However,owing to the large interstitial spaces of the liver,there is a reduction in the natural contrast gradient between lesions ...BACKGROUND:Contrast agents help to improve visibility in magnetic resonance(MR)imaging.However,owing to the large interstitial spaces of the liver,there is a reduction in the natural contrast gradient between lesions and healthy tissue.This study was undertaken to evaluate the efficacy and safety of the liverspecific MR imaging contrast agent gadoxetate disodium(GdEOB-DTPA)in Chinese patients.METHODS:This was a single-arm,open-label,multicenter study in patients with known or suspected focal liver lesions referred for contrast-enhanced MR imaging.MR imaging was performed in 234 patients before and after a single intravenous bolus of Gd-EOB-DTPA(0.025 mmol/kg body weight).Images were evaluated by clinical study investigators and three independent,blinded radiologists.The primary efficacy endpoint was sensitivity in lesion detection.RESULTS:Gd-EOB-DTPA improved sensitivity in lesion detection by 9.46%compared with pre-contrast imaging for the average of the three blinded readers(94.78%vs 85.32%for Gd-EOB-DTPA vs pre-contrast,respectively).Improvements in detection were more pronounced in lesions less than 1cm.Gd-EOB-DTPA improved diagnostic accuracy in lesion classification.CONCLUSIONS:This open-label study demonstrated that Gd-EOB-DTPA improves diagnostic sensitivity in liver lesions,particularly in those smaller than 1 cm.Gd-EOB-DTPA also significantly improves the diagnostic accuracy in lesion classification,and furthermore,Gd-EOB-DTPA is safe in Chinese patients with liver lesions.展开更多
In order to suppress the fast decrease of the transfer efficiency of magnetic resonance coupled wireless power transfer system(MRCWPTS) with distance increase,this paper investigates the impact factors of the system t...In order to suppress the fast decrease of the transfer efficiency of magnetic resonance coupled wireless power transfer system(MRCWPTS) with distance increase,this paper investigates the impact factors of the system transfer efficiency and is,then formulates a new efficiency optimal control method based on frequency control.Based upon this control method two optimal control schemes are designed to achieve transfer efficiency control of the system.Simulations and experiments show that the proposed efficiency optimal control method can effectively stabilize the system transfer efficiency in a certain range so as to successfully solve the subtle issue of transfer efficiency variation with distance.展开更多
Using a dedicated data sample taken in 2018 on the J/ψpeak,we perform a detailed study of the trigger efficiencies of the BESIII detector.The efficiencies are determined from three representative physics processes,na...Using a dedicated data sample taken in 2018 on the J/ψpeak,we perform a detailed study of the trigger efficiencies of the BESIII detector.The efficiencies are determined from three representative physics processes,namely Bhabha scattering,dimuon production and generic hadronic events with charged particles.The combined efficiency of all active triggers approaches 100%in most cases,with uncertainties small enough not to affect most physics analyses.展开更多
N6-methyladenosine(m6A),and its reader protein YTHDF1,play a pivotal role in human tumorigenesis by affecting nearly everystage of RNA metabolism.Autophagy activation is one of the ways by which cancer cells survive h...N6-methyladenosine(m6A),and its reader protein YTHDF1,play a pivotal role in human tumorigenesis by affecting nearly everystage of RNA metabolism.Autophagy activation is one of the ways by which cancer cells survive hypoxia.However,the possibleinvolvement of m6A modification of mRNA in hypoxia-induced autophagy was unexplored in human hepatocellular carcinoma(HCO).In this study,specific variations in YTHDF1 expression were detected in YTHDF1-overexpressing,knockout,and-knockdownHCC cells,HCC organoids,and HCC patient-derived xenograft(PDX)murine models.YTHDF1 expression and hypoxia inducedautophagy were significantly correlated in vitro;signifhcant overexpression of YTHDF1 in HCC tissues was associated with poorprognosis,Multivariate cox regression analysis identihed YTHDF1 expression as an independent prognostic factor in patients withHCC.Multiple HC models conhrmed that YTHDF1 deficiency inhibited HCC autophagy,growth,and metastasis.Luciferase reporterassays and chromatin immunoprecipitation demonstrated that HlIF-1a regulated YTHDF1 transcription by directly binding to itspromoter region under hypoxia.The results of methylated RNA immunoprecipitation sequencing,proteomics,and polysomeprofling indicated that YTHDF1 contibuted to the translation of autophagy-related genes ATG2A and ATG14 by binding to m6A-modifhed ATG2A and ATG14 mRNA,thus facilitating autophagy and autophagy-related malignancy of HCC.Taken together,HlE-1d-induced YTHDF1 expression was associated with hypoxia-induced autophagy and autophagy-related HCC progression via promoting translation of autophagy-related genes ATG2A and ATG14 in a m6A-dependent manner.Our fndings suggest thatYTHDF1 is a potential prognostic biomarker and therapeutic target for patients with HCC.展开更多
Harmonic manipulations are important for applications such as wireless communications,radar detection and biological monitoring.A general approach to tailor the harmonics involves the use of additional amplifiers and ...Harmonic manipulations are important for applications such as wireless communications,radar detection and biological monitoring.A general approach to tailor the harmonics involves the use of additional amplifiers and phase shifters for the precise control of harmonic amplitudes and phases after the mixing process;however,this approach leads to issues of high cost and system integration.Metasurfaces composed of a periodic array of subwavelength resonators provide additional degrees of freedom to realize customized responses to incident light and highlight the possibility for nonlinear control by taking advantage of time-domain properties.Here,we designed and experimentally characterized a reflective time-domain digital coding metasurface,with independent control of the harmonic amplitude and phase.As the reflection coefficient is dynamically modulated in a predefined way,a large conversion rate is observed from the carrier signal to the harmonic components,with magnitudes and phases that can be accurately and separately engineered.In addition,by encoding the reflection phases of the meta-atoms,beam scanning for multiple harmonics can be implemented via different digital coding sequences,thus removing the need for intricate phase-shift networks.This work paves the way for efficient harmonic control for applications in communications,radar,and related areas.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
基金Supported in part by National Key Basic Research Program of China (2015CB856700)National Natural Science Foundation of China (NSFC) (11335008,11425524, 11625523, 11635010, 11735014, 11822506, 11935018)+18 种基金the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Programthe CAS Center for Excellence in Particle Physics (CCEPP)Joint Large-Scale Scientific Facility Funds of the NSFC and CAS (U1532257, U1532258, U1732263)CAS Key Research Program of Frontier Science (QYZDJ-SSW-SLH003, QYZDJ-SSW-SLH040)100 Talents Program of CASCAS PIFIthe Thousand Talents Program of ChinaIN-PAC and Shanghai Key Laboratory for Particle Physics and CosmologyGerman Research Foundation DFG under Contracts NosCollaborative Research Center CRC 1044, FOR 2359Istituto Nazionale di Fisica Nucleare, ItalyKoninklijke Nederlandse Akademie van Wetenschappen (KNAW) (530-4CDP03)Ministry of Development of Turkey (DPT2006K-120470)National Science and Technology fundThe Knut and Alice Wallenberg Foundation (Sweden) (2016.0157)The Swedish Research CouncilU. S. Department of Energy (DE-FG02-05ER41374, DESC-0010118, DE-SC-0012069)University of Groningen (Ru G) and the Helmholtzzentrum fuer Schwerionenforschung Gmb H (GSI), Darmstadtthe Russian Ministry of Science and Higher Education (14.W03.31.0026).
文摘There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESⅢ and B factories, and the observation of an intriguing proton-antiproton threshold enhancement and the possibly related X(1835) meson state at BESⅢ, as well as the threshold measurements of charm mesons and charm baryons. We present a detailed survey of the important topics in tau-charm physics and hadron physics that can be further explored at BESⅢ during the remaining operation period of BEPCⅡ. This survey will help in the optimization of the data-taking plan over the coming years, and provides physics motivation for the possible upgrade of BEPCⅡ to higher luminosity.
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.
文摘To explore the effect of early enteral nutrition （EN） on postoperative nutritional status, intestinal permeability, and immune 6anction in elderly patients with esophageal cancer or cardiac cancer. Methods： A total of 96 patients with esophageal cancer or cardiac cancer who underwent surgical treatment in our hospital from June 2007 to December 2010 were enrolled in this study. They were divided into EN group （n=50） and parenteral nutrition （PN） group （n=46） based on the nutrition support modes. The body weight, time to first flatus/defecation, average hospital stay, complications and mortality after the surgery as well as the liver function indicators were recorded and analyzed. Peripheral blood samples were collected on the days 1, 4 and 7 after surgery. The plasma diamine oxidase （DAO） activity and D-lactate level were determined to assess the intestinal permeability. The plasma endotoxin levels were determined using dynamic turbidimetric assay to assess the protective effect of EN on intestinal mucosal barrier. The postoperative blood levels of inflammatory cytokines and immunoglobulins were determined using enzyme- linked immunosorbent assay （ELISA）. Results： After the surgery, the time to first flatus/defecation, average hospital stay, and complications were significantly less in the EN group than those in the PN group （P〈0.05）, whereas the EN group had significantly higher albumin levels than the PN group （P〈0.05）. On the 7th postoperative day, the DAO activity, D-lactate level and endotoxin contents were significantly lower in the EN group than those in the PN group （all P〈0.05）. In addition, the EN group had significantly higher IgA, IgG, IgM, and CD4 levels than the PN group （P〈0.05） but significantly lower IL-2, IL-6, and TNF-a levels （P〈0.05）. Conclusions： In elderly patients with esophageal cancer or cardiac cancer, early EN after surgery can effectively improve the nutritional status, protect intestinal mucosal barrier （by reducing plasma
基金supported by NSFC (nos 61471168, 61571187,61301043,and 61527806)China Postdoctoral Science Foundation (2016T90403)the Economical Forest Cultivation and Utilization of 2011 Collaborative Innovation Center in Hunan Province [(2013)448]
文摘Tissue engineering has become a promising strategy for repairing damaged cartilage and bone tissue. Among the scaffolds for tissue-engineering applications, injectable hydrogels have demonstrated great potential for use as three-dimensional cell culture scaffolds in cartilage and bone tissue engineering, owing to their high water content, similarity to the natural extracellular matrix(ECM), porous framework for cell transplantation and proliferation, minimal invasive properties, and ability to match irregular defects. In this review, we describe the selection of appropriate biomaterials and fabrication methods to prepare novel injectable hydrogels for cartilage and bone tissue engineering. In addition, the biology of cartilage and the bony ECM is also summarized. Finally, future perspectives for injectable hydrogels in cartilage and bone tissue engineering are discussed.
基金supported by the National High-tech R&D Program of China(2009AA122003)
文摘Four wetland maps for all China have been produced,based on Landsat and CBERS-02B remote sensing data between 1978 and 2008 (1978,1990,2000 and 2008).These maps were mainly developed by manual interpretation and validated by substantial field investigation in 2009.Based on these maps,we analyzed the 2008 wetland distribution in China and discussed wetland changes and their drivers over the past 30 years.(i) There were about 324097 km 2 of wetlands in 2008,for which inland marshes or swamps were the most common wetland type (35%),with lakes (26%) second.Most of the wetlands were in Heilongjiang,Inner Mongolia,Qinghai and Tibet,occupying about 55% of the national wetland area.(ii) From 1978 to 2008,China's wetland area continually and significantly decreased,by about 33% based on changes in the wetland map.This was in sharp contrast to the increase in artificial wetlands,which increased by about 122%.Inland marshes accounted for the main loss of total wetlands from 1978 to 2000.From 2000 through 2008,riverine and lacustrine wetlands constituted the main wetland loss.Fortunately however,the rate of wetland loss decreased from 5523 to 831 km 2 /a.(iii) The change ratio of lost natural wetlands (including inland and coastal wetlands) to non-wetlands has decreased slightly over the past 30 years.From 1978 to 1990,nearly all natural wetlands (98%) lost were transformed into non-wetlands.However,the ratio declined to 86% from 1990 to 2000,and to 77% from 2000 to 2008.(iv) All Chinese provinces were divided into three groups according to patterns of wetland changes,which could relate to the driving forces of such changes.Tibet was completely different from other provinces,as it was one representative example in which there was a net wetland increase,because of global warming and decreased human activity since 1990.Increased economic development caused considerable wetland loss in most eastern provinces,and artificial wetlands increased.
文摘Machine learning(ML) has been widely applied to the upper layers of wireless communication systems for various purposes, such as deployment of cognitive radio and communication network. However, its application to the physical layer is hampered by sophisticated channel environments and limited learning ability of conventional ML algorithms. Deep learning(DL) has been recently applied for many fields, such as computer vision and natural language processing, given its expressive capacity and convenient optimization capability. The potential application of DL to the physical layer has also been increasingly recognized because of the new features for future communications, such as complex scenarios with unknown channel models, high speed and accurate processing requirements; these features challenge conventional communication theories. This paper presents a comprehensive overview of the emerging studies on DL-based physical layer processing, including leveraging DL to redesign a module of the conventional communication system(for modulation recognition, channel decoding, and detection) and replace the communication system with a radically new architecture based on an autoencoder. These DL-based methods show promising performance improvements but have certain limitations, such as lack of solid analytical tools and use of architectures that are specifically designed for communication and implementation research, thereby motivating future research in this field.
基金The study was supported by National Key Research and Development Program(2018YFA0704100,2018YFA0704104)National Natural Science Foundation of China(81827805,82130060)Jiangsu Provincial Special Program of Medical Science(BE2019750).The funding sources had no role in the writing of the report,or decision to submit the paper for publication.
文摘There is considerable potential for integrating transarterial chemoembolization(TACE),programmed death-(ligand)1(PD-[L]1)inhibitors,and molecular targeted treatments(MTT)in hepatocellular carcinoma(HCC).It is necessary to investigate the therapeutic efficacy and safety of TACE combined with PD-(L)1 inhibitors and MTT in real-world situations.In this nationwide,retrospective,cohort study,826 HCC patients receiving either TACE plus PD-(L)1 blockades and MTT(combination group,n=376)or TACE monotherapy(monotherapy group,n=450)were included from January 2018 to May 2021.The primary endpoint was progression-free survival(PFS)according to modified RECIST.The secondary outcomes included overall survival(OS),objective response rate(ORR),and safety.We performed propensity score matching approaches to reduce bias between two groups.After matching,228 pairs were included with a predominantly advanced disease population.Median PFS in combination group was 9.5 months(95%confidence interval[CI],8.4-11.0)versus 8.0 months(95%CI,6.6-9.5)(adjusted hazard ratio[HR],0.70,P=0.002).OS and ORR were also significantly higher in combination group(median OS,19.2[16.1-27.3]vs.15.7 months[13.0-20.2];adjusted HR,0.63,P=0.001;ORR,60.1%vs.32.0%;P<0.001).Grade 3/4 adverse events were observed at a rate of 15.8%and 7.5%in combination and monotherapy groups,respectively.Our results suggest that TACE plus PD-(L)1 blockades and MTT could significantly improve PFS,OS,and ORR versus TACE monotherapy for Chinese patients with predominantly advanced HCC in real-world practice,with an acceptable safety profile.
基金Supported by the Open Foundation of State Key Laboratory of Remote Sensing Science,the Institute of Remote Sensing Applications of the Chinese Academy of Sciences and Beijing Normal University (No.2009KFJJ002)the National Natural Science Foundation of China (No.30590370)
文摘Soil salinization is one of the most common land degradation processes. In this study, spectral measurements of saline soil samples collected from the Yellow River Delta region of China were conducted in laboratory and hyperspectral data were acquired from an EO-1 Hyperion sensor to quantitatively map soil salinity in the region. A soil salinity spectral index (SSI) was constructed from continuum-removed reflectance (CR-reflectance) at 2052 and 2203 nm, to analyze the spectral absorption features of the salt-affected soils. There existed a strong correlation (r = 0.91) between the SSI and soil salt content (SSC). Then, a model for estimation of SSC with SSI was established using univariate regression and validation of the model yielded a root mean square error (RMSE) of 0.986 and an R2 of 0.873. The model was applied to a Hyperion reflectance image on a pixel-by-pixel basis and the resulting quantitative salinity map was validated successfully with RMSE = 1.921 and R2 = 0.627. These suggested that the satellite hyperspectral data had the potential for predicting SSC in a large area.
基金Project(41877272)supported by the National Natural Science Foundation of ChinaProject(2020zzts715)supported by the Fundamental Research Funds for the Central Universities of Central South University,ChinaProject(2242020R10023)supported by the Fundamental Research Funds for the Central Universities of Southeast University,China。
文摘To review the rockburst proneness(or tendency)criteria of rock materials and compare the judgment accuracy of them,twenty criteria were summarized,and their judgment accuracy was evaluated and compared based on the laboratory tests on fourteen types of rocks.This study begins firstly by introducing the twenty rockburst proneness criteria,and their origins,definitions,calculation methods and grading standards were summarized in detail.Subsequently,to evaluate and compare the judgment accuracy of the twenty criteria,a series of laboratory tests were carried out on fourteen types of rocks,and the rockburst proneness judgment results of the twenty criteria for the fourteen types of rocks were obtained accordingly.Moreover,to provide a unified basis for the judgment accuracy evaluation of above criteria,a classification standard(obtained according to the actual failure results and phenomena of rock specimen)of rockburst proneness in laboratory tests was introduced.The judgment results of the twenty criteria were compared with the judgment results of this classification standard.The results show that the judgment results of the criterion based on residual elastic energy(REE)index are completely consistent with the actual rockburst proneness,and the other criteria have some inconsistent situations more or less.Moreover,the REE index is based on the linear energy storage law and defined in form of a difference value and considered the whole failure process,and these superior characteristics ensure its accuracy.It is believed that the criterion based on REE index is comparatively more accurate and scientific than other criteria,and it can be recommended to be applied to judge the rockburst proneness of rock materials.
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 in part by the National Key Research and Development Program of China(2017YFA0700201,2017YFA0700202,and 2017YFA0700203)in part by the National Natural Science Foundation of China(61631007,61571117,61501112,61501117,61522106,61731010,61735010,61722106,61701107,and 61701108)+1 种基金in part by the 111 Project(111-2-05)in part by the Fund for International Cooperation and Exchange of the National Natural Science Foundation of China(61761136007).
文摘Intelligence at either the material or metamaterial level is a goal that researchers have been pursuing.From passive to active,metasurfaces have been developed to be programmable to dynamically and arbitrarily manipulate electromagnetic(EM)wavefields.However,the programmable metasurfaces require manual control to switch among different functionalities.Here,we put forth a smart metasurface that has self-adaptively reprogrammable functionalities without human participation.The smart metasurface is capable of sensing ambient environments by integrating an additional sensor(s)and can adaptively adjust its EM operational functionality through an unmanned sensing feedback system.As an illustrative example,we experimentally develop a motion-sensitive smart metasurface integrated with a three-axis gyroscope,which can adjust self-adaptively the EM radiation beams via different rotations of the metasurface.We develop an online feedback algorithm as the control software to make the smart metasurface achieve single-beam and multibeam steering and other dynamic reactions adaptively.The proposed metasurface is extendable to other physical sensors to detect the humidity,temperature,illuminating light,and so on.Our strategy will open up a new avenue for future unmanned devices that are consistent with the ambient environment.
基金supported by the National Natural Science Foundation of China(grants 61927805 , 51522302)the NSAF Foundation of China(grant U1530260)+2 种基金the Natural Science Foundation of Jiangsu(Grant no.BE2018707)the Special Fund for Military Medical Science(grants BWS16J007 , AWS17J009)the China Postdoctoral Science Foundation funded project(2019M663090).
文摘A patch with the capability of avoiding wound infection and promoting tissue remolding is of great value for wound healing.In this paper,we develop a biomass chitosan microneedle array(CSMNA)patch integrated with smart responsive drug delivery for promoting wound healing.Chitosan possesses many outstanding features such as the natural antibacterial property and has been widely utilized for wound healing.Besides,the microstructure of microneedles enables the effective delivery of loaded drugs into the target area and avoids the excessive adhesion between the skin and the patch.Also,vascular endothelial growth factor(VEGF)is encapsulated in the micropores of CSMNA by temperature sensitive hydrogel.Therefore,the smart release of the drugs can be controllably realized via the temperature rising induced by the inflammation response at the site of wounds.It is demonstrated that the biomass CSMNA patch can promote inflammatory inhibition,collagen deposition,angiogenesis,and tissue regeneration during the wound closure.Thus,this versatile CSMNA patch is potentially valuable for wound healing in clinical applications.
基金This work was supported by the National High Tech Projects(2012AA030402 and 2011AA010202)the National Science Foundation of China(61138001,61171024,61171026,61371035 and 11227904)+2 种基金the 111 Project(111-2-05)the Natural Science Foundation of Jiangsu Province(BK2012019)and the 973 Program(2014CB339800).
文摘The terahertz region is a special region of the electromagnetic spectrum that incorporates the advantages of both microwaves and infrared light waves.In the past decade,metamaterials with effective medium parameters or gradient phases have been studied to control terahertz waves and realize functional devices.Here,we present a new approach to manipulate terahertz waves by using coding metasurfaces that are composed of digital coding elements.We propose a general coding unit based on a Minkowski closed-loop particle that is capable of generating 1-bit coding(with two phase states of 0 and 180°),2-bit coding(with four phase states of 0,90°,180°,and 270°),and multi-bit coding elements in the terahertz frequencies by using different geometric scales.We show that multi-bit coding metasurfaces have strong abilities to control terahertz waves by designing-specific coding sequences.As an application,we demonstrate a new scattering strategy of terahertz waves—broadband and wide-angle diffusion—using a 2-bit coding metasurface with a special coding design and verify it by both numerical simulations and experiments.The presented method opens a new route to reducing the scattering of terahertz waves.
基金Acknowledgements The authors would like to thank Prof. Wei Ji from Renmin University for his kindness in sharing with us the unpublished results on the electronic structure calculations of black phosphorus, Prof. Pingheng Tan for his guidance on early Raman characterization, and Dr. Shuo Ding on her assistance with obtaining the optical image used in TOC. This work is financially supported by the National Natural Science Foundation of China （Nos. 51222202, 11104026, and 61376104）, the National Basic Research Program of China （No. 2014CB932500） and the Program for Innovative Research Teams in Universities of the Ministry of Education of China （No. IRT13037） and the Fundamental Research Funds for the Central Universities （No. 2014XZZX003-07）.
文摘There have been continuous efforts to seek novel functional two-dimensional semiconductors with high performance for future applications in nanoelectronics and optoelectronics. In this work, we introduce a successful experimental approach to fabricate monolayer phosphorene by mechanical cleavage and a subsequent Ar＊ plasma thinning process. The thickness of phosphorene is unambiguously determined by optical contrast spectra combined with atomic force microscopy （AFM）. Raman spectroscopy is used to characterize the pristine and plasma-treated samples. The Raman frequency of the A2g mode stiffens, and the intensity ratio of A2g to Alg modes shows a monotonic discrete increase with the decrease of phosphorene thickness down to a monolayer. All those phenomena can be used to identify the thickness of this novel two-dimensional semiconductor. This work on monolayer phosphorene fabrication and thickness determination will facilitate future research on phosphorene.
基金supported by a grant from Bayer HealthCare/Bayer Schering Pharma AG
文摘BACKGROUND:Contrast agents help to improve visibility in magnetic resonance(MR)imaging.However,owing to the large interstitial spaces of the liver,there is a reduction in the natural contrast gradient between lesions and healthy tissue.This study was undertaken to evaluate the efficacy and safety of the liverspecific MR imaging contrast agent gadoxetate disodium(GdEOB-DTPA)in Chinese patients.METHODS:This was a single-arm,open-label,multicenter study in patients with known or suspected focal liver lesions referred for contrast-enhanced MR imaging.MR imaging was performed in 234 patients before and after a single intravenous bolus of Gd-EOB-DTPA(0.025 mmol/kg body weight).Images were evaluated by clinical study investigators and three independent,blinded radiologists.The primary efficacy endpoint was sensitivity in lesion detection.RESULTS:Gd-EOB-DTPA improved sensitivity in lesion detection by 9.46%compared with pre-contrast imaging for the average of the three blinded readers(94.78%vs 85.32%for Gd-EOB-DTPA vs pre-contrast,respectively).Improvements in detection were more pronounced in lesions less than 1cm.Gd-EOB-DTPA improved diagnostic accuracy in lesion classification.CONCLUSIONS:This open-label study demonstrated that Gd-EOB-DTPA improves diagnostic sensitivity in liver lesions,particularly in those smaller than 1 cm.Gd-EOB-DTPA also significantly improves the diagnostic accuracy in lesion classification,and furthermore,Gd-EOB-DTPA is safe in Chinese patients with liver lesions.
文摘In order to suppress the fast decrease of the transfer efficiency of magnetic resonance coupled wireless power transfer system(MRCWPTS) with distance increase,this paper investigates the impact factors of the system transfer efficiency and is,then formulates a new efficiency optimal control method based on frequency control.Based upon this control method two optimal control schemes are designed to achieve transfer efficiency control of the system.Simulations and experiments show that the proposed efficiency optimal control method can effectively stabilize the system transfer efficiency in a certain range so as to successfully solve the subtle issue of transfer efficiency variation with distance.
基金Supported in part by National Key Basic Research Program of China(2015CB856700)National Natural Science Foundation of China(NSFC)(11625523,11635010,11735014,11822506,11835012,11935015,11935016,11935018,11961141012)+15 种基金the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility ProgramJoint Large-Scale Scientific Facility Funds of the NSFC and CAS(U 1732263,U 1832207)CAS Key Research Program of Frontier Sciences(QYZDJ-SSWSLH003,QYZDJ-SSW-SLH040)100 Talents Program of CASINPAC and Shanghai Key Laboratory for Particle Physics and CosmologyERC(758462)German Research Foundation DFG under Contracts Nos.Collaborative Research Center CRC 1044,FOR 2359Istituto Nazionale di Fisica Nucleare,ItalyMinistry of Development o f Turkey(DPT2006K-120470)National Science and Technology fundOlle Engkvist Foundation(200-0605)STFC(United Kingdom)The Knut and Alice Wallenberg Foundation(Sweden)(2016.0157)The Royal Society,UK(DH140054,DH160214)The Swedish Research CouncilU.S.Department of Energy(DEFG02-05ER41374,DE-SC-0012069)。
文摘Using a dedicated data sample taken in 2018 on the J/ψpeak,we perform a detailed study of the trigger efficiencies of the BESIII detector.The efficiencies are determined from three representative physics processes,namely Bhabha scattering,dimuon production and generic hadronic events with charged particles.The combined efficiency of all active triggers approaches 100%in most cases,with uncertainties small enough not to affect most physics analyses.
基金supported by the Major Program of the National Natural Science Foundation of China(Grant No.81530048,31930020)Key Laboratory of Liver Transplantation,Chinese Academy of Medical Sciences(Grant No.2017PT32008,2018PT31043,2019PT320015)+2 种基金the National Natural Science Foundation of China(Grant No.81870488,81872365,81972266,81772569)the Shenzhen Foundation of Science and Technology(Grant No.JCYJ20170817172116272)the Sanm ing Project of Medicine in Shenzhen(Grant No.SZSM201812079).
文摘N6-methyladenosine(m6A),and its reader protein YTHDF1,play a pivotal role in human tumorigenesis by affecting nearly everystage of RNA metabolism.Autophagy activation is one of the ways by which cancer cells survive hypoxia.However,the possibleinvolvement of m6A modification of mRNA in hypoxia-induced autophagy was unexplored in human hepatocellular carcinoma(HCO).In this study,specific variations in YTHDF1 expression were detected in YTHDF1-overexpressing,knockout,and-knockdownHCC cells,HCC organoids,and HCC patient-derived xenograft(PDX)murine models.YTHDF1 expression and hypoxia inducedautophagy were significantly correlated in vitro;signifhcant overexpression of YTHDF1 in HCC tissues was associated with poorprognosis,Multivariate cox regression analysis identihed YTHDF1 expression as an independent prognostic factor in patients withHCC.Multiple HC models conhrmed that YTHDF1 deficiency inhibited HCC autophagy,growth,and metastasis.Luciferase reporterassays and chromatin immunoprecipitation demonstrated that HlIF-1a regulated YTHDF1 transcription by directly binding to itspromoter region under hypoxia.The results of methylated RNA immunoprecipitation sequencing,proteomics,and polysomeprofling indicated that YTHDF1 contibuted to the translation of autophagy-related genes ATG2A and ATG14 by binding to m6A-modifhed ATG2A and ATG14 mRNA,thus facilitating autophagy and autophagy-related malignancy of HCC.Taken together,HlE-1d-induced YTHDF1 expression was associated with hypoxia-induced autophagy and autophagy-related HCC progression via promoting translation of autophagy-related genes ATG2A and ATG14 in a m6A-dependent manner.Our fndings suggest thatYTHDF1 is a potential prognostic biomarker and therapeutic target for patients with HCC.
基金supported by the National Key Research and Development Program of China under Grant Nos.2017YFA0700201,2017YFA0700202,2017YFA0700203the National Science Foundation of China(61631007,61571117,61138001,61371035,61722106,61731010,11227904)the 111 Project(111-2-05).
文摘Harmonic manipulations are important for applications such as wireless communications,radar detection and biological monitoring.A general approach to tailor the harmonics involves the use of additional amplifiers and phase shifters for the precise control of harmonic amplitudes and phases after the mixing process;however,this approach leads to issues of high cost and system integration.Metasurfaces composed of a periodic array of subwavelength resonators provide additional degrees of freedom to realize customized responses to incident light and highlight the possibility for nonlinear control by taking advantage of time-domain properties.Here,we designed and experimentally characterized a reflective time-domain digital coding metasurface,with independent control of the harmonic amplitude and phase.As the reflection coefficient is dynamically modulated in a predefined way,a large conversion rate is observed from the carrier signal to the harmonic components,with magnitudes and phases that can be accurately and separately engineered.In addition,by encoding the reflection phases of the meta-atoms,beam scanning for multiple harmonics can be implemented via different digital coding sequences,thus removing the need for intricate phase-shift networks.This work paves the way for efficient harmonic control for applications in communications,radar,and related areas.
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.
