Objective: Survival benefit of adjuvant chemotherapy(AC) of patients with intrapulmonary lymph node(IPLN)metastasis(level 12-14) needs investigation.We evaluated the impact of AC on patients whose metastatic nodes wer...Objective: Survival benefit of adjuvant chemotherapy(AC) of patients with intrapulmonary lymph node(IPLN)metastasis(level 12-14) needs investigation.We evaluated the impact of AC on patients whose metastatic nodes were limited to intrapulmonary levels after systematic dissection of N1 nodes.Methods: First,155 consective cases of lung cancer confirmed as pathologic N1 were collected and evaluated.Patients received systematic dissection of N2 and N1 nodes.For patients with IPLN metastasis,survival outcomes were compared between those receiving AC and those not receiving AC.Results: In this group,112 cases(72.3%) had IPLN metastasis and 55 cases(35.5%) had N1 involvement limited to level 13-14 without further disease spread to higher levels.Patients with IPLN involvement had a better prognosis than that of patients with hilar-interlobar involvement.For the intrapulmonary N1 group(level 12-14-positive,level 10-11-negative or unknown,n=112),no survival benefit was found between the AC group and nonAC group [5-year overall survival(OS): 54.6±1.6 vs.50.4±2.4 months,P=0.177].However,76 of 112 cases for whom harvesting of level-10 and level-11 nodes was done did not show cancer involvement in pathology reports(level 12-14-positive,level 10-11 both negative),oncologic outcome was better for patients receiving AC than those not receiving AC in this subgroup(5-year OS: 57.3±1.5 vs.47.1±3.2 months,P=0.002).Conclusions: Oncologic outcome may be improved by AC for patients with involvement of N1 nodes limited to intrapulmonary levels after complete examination of N1 nodes.展开更多
Objective: As a novel blood supply pattern, vasculogenic mimicry(VM) has attracted increasingly attention in recent years, which may partly compensate for the absence of feeding and facilitate tumor perfusion. However...Objective: As a novel blood supply pattern, vasculogenic mimicry(VM) has attracted increasingly attention in recent years, which may partly compensate for the absence of feeding and facilitate tumor perfusion. However, anti-angiogenic drugs have little effect on VM. The grape seed proanthocyanidins(GSPs), a kind of promising bioactive phytochemical, has shown anti-carcinogenesis and anti-angiogenic in several tumor models. However, GSPs regulation of VM and its possible mechanisms in a H22 hepatoma carcinoma model remain not clear. The aim of this study was to examine the effects of GSPs on proliferation and VM in a H22 hepatoma carcinoma model and to investigate the underlying mechanism. Methods: Seventy-five mice were divided into the control group and experimental groups treated with different concentration of GSPs. CD34-PAS dual staining was employed to identify the VM structure. The immunohistochemical staining for investigating the expression of VEGF, Eph A2 and MMP-2 protein was performed. Results: Treatment of the H22 model with Endostar(4 mg/kg), 50, 100, 200 mg/kg of the GSPs resulted in 6.87%, 17.81%, 27.43%, 53.52% inhibition in tumor growth, respectively. The mean weight of tumors were significantly lower in GSPs(100 mg/kg) and GSPs(200 mg/kg) groups than in the control group(all P < 0.01). Similarly, compared with the control group, the number of VM channels were significantly reduced in GSPs(100 mg/kg) and GSPs(200 mg/kg) groups(all P < 0.01). Immunohistochemistry showed significant decreases in the expression levels of VEGF, Eph A2 and MMP-2 protein in GSPs(100 mg/kg) and GSPs(200 mg/kg) groups when compared with control group(all P < 0.001). Conclusion: This is the first report providing evidence that GSPs inhibit the VM structure by regulation of the VEGF/Eph A2/MMPs signaling pathway. Therefore, we concluded that GSPs has the potential of being a clinical anti-VM inhibitor.展开更多
As a foundation of quantum physics,uncertainty relations describe ultimate limit for the measurement uncertainty of incompatible observables.Traditionally,uncertainty relations are formulated by mathematical bounds fo...As a foundation of quantum physics,uncertainty relations describe ultimate limit for the measurement uncertainty of incompatible observables.Traditionally,uncertainty relations are formulated by mathematical bounds for a specific state.Here we present a method for geometrically characterizing uncertainty relations as an entire area of variances of the observables,ranging over all possible input states.We find that for the pair of position and momentum operators,Heisenberg's uncertainty principle points exactly to the attainable area of the variances of position and momentum.Moreover,for finite-dimensional systems,we prove that the corresponding area is necessarily semialgebraic;in other words,this set can be represented via finite polynomial equations and inequalities,or any finite union of such sets.In particular,we give the analytical characterization of the areas of variances of(a)a pair of one-qubit observables and(b)a pair of projective observables for arbitrary dimension,and give the first experimental observation of such areas in a photonic system.展开更多
In gas insulation switch(GIS)substation,secondary devices such as linemonitoring devices are placed in the switching field,and these electronic devices are vulnerable to transient electromagnetic interference caused b...In gas insulation switch(GIS)substation,secondary devices such as linemonitoring devices are placed in the switching field,and these electronic devices are vulnerable to transient electromagnetic interference caused by switching operation.In order to facilitate the measurement and research of electromagnetic disturbance data under different working conditions,a simulation test device is developed in this paper,which can be used to simulate electromagnetic disturbance of GIS substation sensor and secondary device port under switch operation.A four-channel parallel gas switch was designed,and the main characteristic parameters of electromagnetic disturbance generated by the simulation device were measured by using high-frequency pulse power supply as the excitation source.The comparison between the measured waveform and the measured disturbance characteristic parameters of GIS substation shows that it is in good agreement with the measured waveform characteristics,conforms to the basic characteristics of damped oscillation wave,and can be used in the secondary equipment port disturbance voltage coupling characteristics,protection measures evaluation and assessment method research.展开更多
Epithelial Protein Lost in Neoplasm (EPLIN) is a cytoskeletal associated protein implicated in regulating actin dynamoics and cellular motility and whose expression is frequently downregulated in a number of human can...Epithelial Protein Lost in Neoplasm (EPLIN) is a cytoskeletal associated protein implicated in regulating actin dynamoics and cellular motility and whose expression is frequently downregulated in a number of human cancers. The current study examined the expression levels of EPLIN-α in a pulmonary cancer cohort and its association with clinical pathological factors using quantitative polymerase chain reaction. Additionally, EPLIN-α was over-expressed in the SKMES-1 pulmonary cancer cell line through transfection with a plasmid containing the expression sequence for EPLIN-α. The role of EPLIN-α was subsequently examined using a variety of in vitro functional assays. Decreased levels of EPLIN-α were seen in cancerous tissues compared to normal background tissue. Lower levels of EPLIN-α were also associated with higher TNM stage and nodal involvement. In vitro over-expression of EPLIN-α inhibited SKMES-1 growth rates (p = 0.05 vs. plasmid control) and motility (p = 0.002 vs. plasmid control), though did not have any significant effects on cell-matrix adhesion or cell invasion. Taken together, the current study indicates that lower levels of EPLIN-α may be associated with poorer prognosis and more advanced pulmonary cancer, where this molecule appears to play a suppressive role on cell growth and migration.展开更多
Although notable progress has been made in the study of Steady-State Visual Evoked Potential(SSVEP)-based Brain-Computer Interface(BCI),several factors that limit the practical applications of BCIs still exist.One of ...Although notable progress has been made in the study of Steady-State Visual Evoked Potential(SSVEP)-based Brain-Computer Interface(BCI),several factors that limit the practical applications of BCIs still exist.One of these factors is the importability of the stimulator.In this study,Augmented Reality(AR)technology was introduced to present the visual stimuli of SSVEP-BCI,while the robot grasping experiment was designed to verify the applicability of the AR-BCI system.The offline experiment was designed to determine the best stimulus time,while the online experiment was used to complete the robot grasping task.The offline experiment revealed that better information transfer rate performance could be achieved when the stimulation time is 2 s.Results of the online experiment indicate that all 12 subjects could control the robot to complete the robot grasping task,which indicates the applicability of the AR-SSVEP-humanoid robot(NAO)system.This study verified the reliability of the AR-BCI system and indicated the applicability of the AR-SSVEP-NAO system in robot grasping tasks.展开更多
The large-photon-number quantum state is a fundamental but nonresolved request for practical quantum information applications.We propose an N-photon state generation scheme that is feasible and scalable,using lithium ...The large-photon-number quantum state is a fundamental but nonresolved request for practical quantum information applications.We propose an N-photon state generation scheme that is feasible and scalable,using lithium niobate on insulator circuits.Such a scheme is based on the integration of a common building block called photon-number doubling unit(PDU)for deterministic single-photon parametric downconversion and upconversion.The PDU relies on a 107-optical-quality-factor resonator and mW-level on-chip power,which is within the current fabrication and experimental limits.N-photon state generation schemes,with cluster and Greenberger–Horne–Zeilinger state as examples,are shown for different quantum tasks.展开更多
OBJECTIVE:To observe the therapeutic effect of percutaneous kyphoplasty(PKP) and oral Zishengukang(ZSGK) for the treatment of osteoporotic vertebral compression fractures(OVCFs).METHODS:Seventy patients were randomly ...OBJECTIVE:To observe the therapeutic effect of percutaneous kyphoplasty(PKP) and oral Zishengukang(ZSGK) for the treatment of osteoporotic vertebral compression fractures(OVCFs).METHODS:Seventy patients were randomly divided into a control group(PKP group) and an experimental group(PKP plus ZSGK group).The 35 patients in the experimental group were prescribed 6 g oral ZSGK three times a day for 90 days after PKP.Visual analog pain scale(VAS),Oswestry functional score,vertebral height and Cobb's angle were recorded and compared before treatment and at one week,one month and three months after treatment.RESULTS:Vertebral height and Cobb's angle significantly improved and VAS and Oswestry functional score were significantly lower in both groups after PKP than pre-operatively(P<0.01).Three months after treatment,VAS and Oswestry functional score in the experimental group were lower than controls(P<0.05),even though vertebral height and Cobb's angle were comparable(P>0.05).CONCLUSION:PKP combined with oral ZSGK provide superior short-term and long-term symptom control after OVCF than PKP alone.展开更多
Quantum computing is seeking to realize hardware-optimized algorithms for application-related computational tasks.NP(nondeterministic-polynomial-time)is a complexity class containing many important but intractable pro...Quantum computing is seeking to realize hardware-optimized algorithms for application-related computational tasks.NP(nondeterministic-polynomial-time)is a complexity class containing many important but intractable problems like the satisfiability of potentially conflict constraints(SAT).According to the well-founded exponential time hypothesis,verifying an SAT instance of size n requires generally the complete solution in an O(n)-bit proof.In contrast,quantum verification algorithms,which encode the solution into quantum bits rather than classical bit strings,can perform the verification task with quadratically reduced information about the solution in O~(Õ−−√n)qubits.Here we realize the quantum verification machine of SAT with single photons and linear optics.By using tunable optical setups,we efficiently verify satisfiable and unsatisfiable SAT instances and achieve a clear completeness-soundness gap even in the presence of experimental imperfections.The protocol requires only unentangled photons,linear operations on multiple modes and at most two-photon joint measurements.These features make the protocol suitable for photonic realization and scalable to large problem sizes with the advances in high-dimensional quantum information manipulation and large scale linear-optical systems.Our results open an essentially new route toward quantum advantages and extend the computational capability of optical quantum computing.展开更多
Quantum stochastic phase estimation has many applications in the precise measurement of various physical parameters.Similar to the estimation of a constant phase,there is a standard quantum limit for stochastic phase ...Quantum stochastic phase estimation has many applications in the precise measurement of various physical parameters.Similar to the estimation of a constant phase,there is a standard quantum limit for stochastic phase estimation,which can be obtained with the Mach-Zehnder interferometer and coherent input state.Recently,it has been shown that the stochastic standard quantum limit can be surpassed with nonclassical resources such as squcezed light.However,practical methods to achieve quantum enhancement in the stochastic phase estimation remain largely unexplored.Here we propose a method utilizing the SU(1,1)interferometer and coherent input states to cstimate a stochastic optical phase.As an example,we investigate the Ornstcin-Uhlenback stochastic phase.We analyze the performance of this method for three key estimation problems:prediction,tracking,and smoothing.The results show significant reduction of the mean square error compared with the Mach-Zehnder interferometer under the same photon number flux inside the interferometers.In particular,we show that the method with the SU(1,1)interferometer can achieve fundamental quantum scaling,achieve stochastic Heisenberg scalinga and surpass the precision of the canonical measurement.展开更多
A series of novel phenyl-urea derivatives which can simultaneously activate gluco kinase(GK)and peroxisome proliferator-activated receptorγ(PPARγ)was designed and prepared,and their activation of GK and PPARγ was e...A series of novel phenyl-urea derivatives which can simultaneously activate gluco kinase(GK)and peroxisome proliferator-activated receptorγ(PPARγ)was designed and prepared,and their activation of GK and PPARγ was evaluated.The structure--activity relationships of these compounds are also described.Three compounds showed potent ability to activate both GK and PPARγ.The possible binding mode of one of these compounds with GK and PPARγ were predicted by molecular docking simulation.展开更多
Hollow-core fiber(HCF)promises to unify air-borne light propagation and non-line-of-sight transmission,thus holding great potential for versatile photonics-based quantum information applications.The early version of H...Hollow-core fiber(HCF)promises to unify air-borne light propagation and non-line-of-sight transmission,thus holding great potential for versatile photonics-based quantum information applications.The early version of HCF based on photonic-bandgap guidance has not proven itself a reliable quantum channel because of the poor modal purity in both spatial and polarization domains,as well as significant difficulty in fabrication when the wavelength shifts to the visible region.In this work,based on the polarization degree of freedom,we demonstrate high-fidelity(∼0.98)single-photon transmission and distribution of entangled photons over a 36.4 m hollow-core conjoined-tube fiber(CTF)by using commercial silicon single-photon avalanche photodiodes.Our CTF realizes the combined merits of low loss,high spatial modal purity,low polarization degradation,and low chromatic dispersion.We also demonstrate single-photon low-latency(∼99.96%speed of light in vacuum)transmission,paving the way for extensive uses of HCF links in versatile photonics-based quantum information processing.展开更多
As a method to extract information from optical systems,imaging can be viewed as a parameter estimation problem.The fundamental precision in locating one emitter or estimating the separation between two incoherent emi...As a method to extract information from optical systems,imaging can be viewed as a parameter estimation problem.The fundamental precision in locating one emitter or estimating the separation between two incoherent emitters is bounded below by the multiparameter quantum Cramér-Rao bound(QCRB).Multiparameter QCRB gives an intrinsic bound in parameter estimation.We determine the ultimate potential of quantum-limited imaging for improving the resolution of a far-field,diffraction-limited optical field within the paraxial approximation.We show that the quantum Fisher information matrix(QFIm)in about one emitter’s position is independent on its true value.We calculate the QFIm of two unequal-brightness emitters’relative positions and intensities;the results show that only when the relative intensity and centroids of two-point sources,including longitudinal and transverse directions,are known exactly,the separation in different directions can be estimated simultaneously with finite precision.Our results give the upper bounds on certain far-field imaging technology and will find wide use in applications from microscopy to astrometry.展开更多
Laser communication using photons should consider not only the transmission environment’s effects,but also the performance of the single-photon detector used and the photon number distribution.Photon communication ba...Laser communication using photons should consider not only the transmission environment’s effects,but also the performance of the single-photon detector used and the photon number distribution.Photon communication based on the superconducting nanowire single-photon detector(SNSPD)is a new technology that addresses the current sensitivity limitations at the level of single photons in deep space communication.The communication’s bit error rate(BER)is limited by dark noise in the space environment and the photon number distribution with a traditional single-pixel SNSPD,which is unable to resolve the photon number distribution.In this work,an enhanced photon communication method was proposed based on the photon number resolving function of four-pixel array SNSPDs.A simulated picture transmission was carried out,and the error rate in this counting mode can be reduced by 2 orders of magnitude when compared with classical optical communication.However,in the communication mode using photon-enhanced counting,the four-pixel response amplitude for counting was found to restrain the communication rate,and this counting mode is extremely dependent on the incident light intensity through experiments,which limits the sensitivity and speed of the SNSPD array’s performance advantage.Therefore,a BER theoretical calculation model for laser communication was presented using the Bayesian estimation algorithm in order to analyze the selection of counting methods for information acquisition under different light intensities and to make better use of the SNSPD array’s high sensitivity and speed and thus to obtain a lower BER.The counting method and theoretical model proposed in this work refer to array SNSPDs in the deep space field.展开更多
Metal chalcogenides (MCs) are significant semiconducting materials possessing a variety of applications in catalysts , thermoelectrics , rewritable memory, thin film transistors (TFTs), and solar cells, usually presen...Metal chalcogenides (MCs) are significant semiconducting materials possessing a variety of applications in catalysts , thermoelectrics , rewritable memory, thin film transistors (TFTs), and solar cells, usually presenting as solid films. Until now, one can deposit the bulk materials on a substrate by either topdown method such as thermal evaporation or bottom-up deposition from molecular precursors. The latter approach, usually described as solution processing, allows low-energy, low-cost, high-speed and high-throughput manufacturing, and is compatible with a variety of substrates .展开更多
In optical metrological protocols to measure physical quantities,it is,in principle,always beneficial to in crease photon number n to improve measurement precision.However,practical constraints prevent the arbitrary i...In optical metrological protocols to measure physical quantities,it is,in principle,always beneficial to in crease photon number n to improve measurement precision.However,practical constraints prevent the arbitrary increase of n due to the imperfections of a practical detector,especially when the detector response is dominated by the saturation effect.In this work,we show that a modified weak measurement protocol,namely,biased weak measurement significantly improves the precision of optical metrology in the presence of saturation effect.This method detects an ultra-small fraction of photons while main tains a considerable amount of metrological information.The biased pre-coupling leads to an additi onal reduction of photons in the post-selection and gene rates an extinction point in the spectrum distribution,which is extremely sensitive to the estimated parameter and difficult to be saturated.Therefore,the Fisher information can be persistently enhanced by increasing the photon number.In our magnetic-sensing experiment,biased weak measurement achieves precision approximately one order of magnitude better than those of previously used methods.The proposed method can be applied in various optical measurement schemes to remarkably mitigate the detector saturation effect with low-cost apparatuses.展开更多
The quantum properties of quantum measurements are indispensable resources in quantum information processing and have drawn extensive research interest.The conventional approach to revealing quantum properties relies ...The quantum properties of quantum measurements are indispensable resources in quantum information processing and have drawn extensive research interest.The conventional approach to revealing quantum properties relies on the reconstruction of entire measurement operators by quantum detector tomography.However,many specific properties can be determined by a part of the matrix components of the measurement operators,which makes it possible to simplify the characterization process.We propose a general framework to directly obtain individual matrix elements of the measurement operators by sequentially measuring two noncompatible observables.This method allows us to circumvent the complete tomography of the quantum measurement and extract the required information.We experimentally implement this scheme to monitor the coherent evolution of a general quantum measurement by determining the off-diagonal matrix elements.The investigation of the measurement precision indicates the good feasibility of our protocol for arbitrary quantum measurements.Our results pave the way for revealing the quantum properties of quantum measurements by selectively determining the matrix components of the measurement operators.展开更多
基金supported in part by National Key R&D Program of China(No.2018YFC0910700)the Beijing Municipal Administration of Hospitals'Youth Programme(No.QML20171103)+2 种基金the Special Fund of Beijing Municipal Administration of Hospitals Clinical Medicine Development(No.XMLX201841)the Beijing Municipal Science&Technology Commission(No.Z161100000516063)Beijing Human Resources and Social Security Bureau(Beijing Millions of Talents Project,2018A05)
文摘Objective: Survival benefit of adjuvant chemotherapy(AC) of patients with intrapulmonary lymph node(IPLN)metastasis(level 12-14) needs investigation.We evaluated the impact of AC on patients whose metastatic nodes were limited to intrapulmonary levels after systematic dissection of N1 nodes.Methods: First,155 consective cases of lung cancer confirmed as pathologic N1 were collected and evaluated.Patients received systematic dissection of N2 and N1 nodes.For patients with IPLN metastasis,survival outcomes were compared between those receiving AC and those not receiving AC.Results: In this group,112 cases(72.3%) had IPLN metastasis and 55 cases(35.5%) had N1 involvement limited to level 13-14 without further disease spread to higher levels.Patients with IPLN involvement had a better prognosis than that of patients with hilar-interlobar involvement.For the intrapulmonary N1 group(level 12-14-positive,level 10-11-negative or unknown,n=112),no survival benefit was found between the AC group and nonAC group [5-year overall survival(OS): 54.6±1.6 vs.50.4±2.4 months,P=0.177].However,76 of 112 cases for whom harvesting of level-10 and level-11 nodes was done did not show cancer involvement in pathology reports(level 12-14-positive,level 10-11 both negative),oncologic outcome was better for patients receiving AC than those not receiving AC in this subgroup(5-year OS: 57.3±1.5 vs.47.1±3.2 months,P=0.002).Conclusions: Oncologic outcome may be improved by AC for patients with involvement of N1 nodes limited to intrapulmonary levels after complete examination of N1 nodes.
文摘Objective: As a novel blood supply pattern, vasculogenic mimicry(VM) has attracted increasingly attention in recent years, which may partly compensate for the absence of feeding and facilitate tumor perfusion. However, anti-angiogenic drugs have little effect on VM. The grape seed proanthocyanidins(GSPs), a kind of promising bioactive phytochemical, has shown anti-carcinogenesis and anti-angiogenic in several tumor models. However, GSPs regulation of VM and its possible mechanisms in a H22 hepatoma carcinoma model remain not clear. The aim of this study was to examine the effects of GSPs on proliferation and VM in a H22 hepatoma carcinoma model and to investigate the underlying mechanism. Methods: Seventy-five mice were divided into the control group and experimental groups treated with different concentration of GSPs. CD34-PAS dual staining was employed to identify the VM structure. The immunohistochemical staining for investigating the expression of VEGF, Eph A2 and MMP-2 protein was performed. Results: Treatment of the H22 model with Endostar(4 mg/kg), 50, 100, 200 mg/kg of the GSPs resulted in 6.87%, 17.81%, 27.43%, 53.52% inhibition in tumor growth, respectively. The mean weight of tumors were significantly lower in GSPs(100 mg/kg) and GSPs(200 mg/kg) groups than in the control group(all P < 0.01). Similarly, compared with the control group, the number of VM channels were significantly reduced in GSPs(100 mg/kg) and GSPs(200 mg/kg) groups(all P < 0.01). Immunohistochemistry showed significant decreases in the expression levels of VEGF, Eph A2 and MMP-2 protein in GSPs(100 mg/kg) and GSPs(200 mg/kg) groups when compared with control group(all P < 0.001). Conclusion: This is the first report providing evidence that GSPs inhibit the VM structure by regulation of the VEGF/Eph A2/MMPs signaling pathway. Therefore, we concluded that GSPs has the potential of being a clinical anti-VM inhibitor.
基金Supported by the National Key Research and Development Program of China(Grant No.2017YFA0303703)the National Natural Science Foundation of China(Grant Nos.91836303,61975077,61490711,11690032,11875160,and U1801661)+5 种基金the Natural Science Foundation of Guangdong Province(Grant No.2017B030308003)the Key R&D Program of Guangdong Province(Grant No.2018B030326001)the Science,Technology and Innovation Commission of Shenzhen Municipality(Grant Nos.JCYJ20170412152620376,JCYJ20170817105046702,and KYTDPT20181011104202253)the Economy,Trade and Information Commission of Shenzhen Municipality(Grant No.201901161512)Guangdong Provincial Key Laboratory(Grant No.2019B121203002)ARC DECRA 180100156 and ARC DP210102449.
文摘As a foundation of quantum physics,uncertainty relations describe ultimate limit for the measurement uncertainty of incompatible observables.Traditionally,uncertainty relations are formulated by mathematical bounds for a specific state.Here we present a method for geometrically characterizing uncertainty relations as an entire area of variances of the observables,ranging over all possible input states.We find that for the pair of position and momentum operators,Heisenberg's uncertainty principle points exactly to the attainable area of the variances of position and momentum.Moreover,for finite-dimensional systems,we prove that the corresponding area is necessarily semialgebraic;in other words,this set can be represented via finite polynomial equations and inequalities,or any finite union of such sets.In particular,we give the analytical characterization of the areas of variances of(a)a pair of one-qubit observables and(b)a pair of projective observables for arbitrary dimension,and give the first experimental observation of such areas in a photonic system.
基金Science and Technology Project of State Grid Corporation of China(Project No.5226SX18000F)Science and Technology Project of State Grid Shaanxi Electric Power Company(Project No.5226KY18002M).
文摘In gas insulation switch(GIS)substation,secondary devices such as linemonitoring devices are placed in the switching field,and these electronic devices are vulnerable to transient electromagnetic interference caused by switching operation.In order to facilitate the measurement and research of electromagnetic disturbance data under different working conditions,a simulation test device is developed in this paper,which can be used to simulate electromagnetic disturbance of GIS substation sensor and secondary device port under switch operation.A four-channel parallel gas switch was designed,and the main characteristic parameters of electromagnetic disturbance generated by the simulation device were measured by using high-frequency pulse power supply as the excitation source.The comparison between the measured waveform and the measured disturbance characteristic parameters of GIS substation shows that it is in good agreement with the measured waveform characteristics,conforms to the basic characteristics of damped oscillation wave,and can be used in the secondary equipment port disturbance voltage coupling characteristics,protection measures evaluation and assessment method research.
文摘Epithelial Protein Lost in Neoplasm (EPLIN) is a cytoskeletal associated protein implicated in regulating actin dynamoics and cellular motility and whose expression is frequently downregulated in a number of human cancers. The current study examined the expression levels of EPLIN-α in a pulmonary cancer cohort and its association with clinical pathological factors using quantitative polymerase chain reaction. Additionally, EPLIN-α was over-expressed in the SKMES-1 pulmonary cancer cell line through transfection with a plasmid containing the expression sequence for EPLIN-α. The role of EPLIN-α was subsequently examined using a variety of in vitro functional assays. Decreased levels of EPLIN-α were seen in cancerous tissues compared to normal background tissue. Lower levels of EPLIN-α were also associated with higher TNM stage and nodal involvement. In vitro over-expression of EPLIN-α inhibited SKMES-1 growth rates (p = 0.05 vs. plasmid control) and motility (p = 0.002 vs. plasmid control), though did not have any significant effects on cell-matrix adhesion or cell invasion. Taken together, the current study indicates that lower levels of EPLIN-α may be associated with poorer prognosis and more advanced pulmonary cancer, where this molecule appears to play a suppressive role on cell growth and migration.
基金Research was supported in part by the National Natural Science Foundation of China(No.62171473)Beijing Science and Technology Program(No.Z201100004420015)Fundamental Research Funds for the Central Universities of China(No.FRF-TP-20-017A1).
文摘Although notable progress has been made in the study of Steady-State Visual Evoked Potential(SSVEP)-based Brain-Computer Interface(BCI),several factors that limit the practical applications of BCIs still exist.One of these factors is the importability of the stimulator.In this study,Augmented Reality(AR)technology was introduced to present the visual stimuli of SSVEP-BCI,while the robot grasping experiment was designed to verify the applicability of the AR-BCI system.The offline experiment was designed to determine the best stimulus time,while the online experiment was used to complete the robot grasping task.The offline experiment revealed that better information transfer rate performance could be achieved when the stimulation time is 2 s.Results of the online experiment indicate that all 12 subjects could control the robot to complete the robot grasping task,which indicates the applicability of the AR-SSVEP-humanoid robot(NAO)system.This study verified the reliability of the AR-BCI system and indicated the applicability of the AR-SSVEP-NAO system in robot grasping tasks.
基金supported by the National Natural Science Foundation of China (22005293, U19A2092 and 22275180)the National Key Research and Development Program of China (2019YFA0405600)+1 种基金the Institute of Energy, Hefei Comprehensive National Science Center (21KZS212)the Collaborative Innovation Program of Hefei Science Center, CAS。
基金supported by the National Key R&D Program of China(No.2019YFA0705000)the Key R&D Program of Guangdong Province(No.2018B030329001)+4 种基金the Leading-edge Technology Program of Jiangsu Natural Science Foundation(No.BK20192001)the National Natural Science Foundation of China(Nos.51890861,11690033,and 11974178)the Excellent Research Program of Nanjing University(No.ZYJH002)the support of the National Postdoctoral Program for Innovative Talents(No.BX2021122)China Postdoctoral Science Foundation(No.2022M711570).
文摘The large-photon-number quantum state is a fundamental but nonresolved request for practical quantum information applications.We propose an N-photon state generation scheme that is feasible and scalable,using lithium niobate on insulator circuits.Such a scheme is based on the integration of a common building block called photon-number doubling unit(PDU)for deterministic single-photon parametric downconversion and upconversion.The PDU relies on a 107-optical-quality-factor resonator and mW-level on-chip power,which is within the current fabrication and experimental limits.N-photon state generation schemes,with cluster and Greenberger–Horne–Zeilinger state as examples,are shown for different quantum tasks.
文摘OBJECTIVE:To observe the therapeutic effect of percutaneous kyphoplasty(PKP) and oral Zishengukang(ZSGK) for the treatment of osteoporotic vertebral compression fractures(OVCFs).METHODS:Seventy patients were randomly divided into a control group(PKP group) and an experimental group(PKP plus ZSGK group).The 35 patients in the experimental group were prescribed 6 g oral ZSGK three times a day for 90 days after PKP.Visual analog pain scale(VAS),Oswestry functional score,vertebral height and Cobb's angle were recorded and compared before treatment and at one week,one month and three months after treatment.RESULTS:Vertebral height and Cobb's angle significantly improved and VAS and Oswestry functional score were significantly lower in both groups after PKP than pre-operatively(P<0.01).Three months after treatment,VAS and Oswestry functional score in the experimental group were lower than controls(P<0.05),even though vertebral height and Cobb's angle were comparable(P>0.05).CONCLUSION:PKP combined with oral ZSGK provide superior short-term and long-term symptom control after OVCF than PKP alone.
基金This work was supported by the National Key Research and Development Program of China(Grant Nos.2019YFA0308700,2017YFA0303703 and 2018YFB1003202)the National Natural Science Foundation of China(Grant Nos.61972191,11690032,61975077 and 91836303)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.020214380068)P.Y.acknowledges financial support by Anhui Initiative in Quantum Information Technologies(Grant No.AHY150100).
文摘Quantum computing is seeking to realize hardware-optimized algorithms for application-related computational tasks.NP(nondeterministic-polynomial-time)is a complexity class containing many important but intractable problems like the satisfiability of potentially conflict constraints(SAT).According to the well-founded exponential time hypothesis,verifying an SAT instance of size n requires generally the complete solution in an O(n)-bit proof.In contrast,quantum verification algorithms,which encode the solution into quantum bits rather than classical bit strings,can perform the verification task with quadratically reduced information about the solution in O~(Õ−−√n)qubits.Here we realize the quantum verification machine of SAT with single photons and linear optics.By using tunable optical setups,we efficiently verify satisfiable and unsatisfiable SAT instances and achieve a clear completeness-soundness gap even in the presence of experimental imperfections.The protocol requires only unentangled photons,linear operations on multiple modes and at most two-photon joint measurements.These features make the protocol suitable for photonic realization and scalable to large problem sizes with the advances in high-dimensional quantum information manipulation and large scale linear-optical systems.Our results open an essentially new route toward quantum advantages and extend the computational capability of optical quantum computing.
基金National Key Research and Development Program of China(2017YFA0303703,2019YFA0308704)National Natural Science Foundation of China(11664017,11590052,11574155,51490711,61973077,91436211,91836303)+3 种基金Fundamental Research Funds for the Central Universitics(No.020214380068)Natural Science Foundjarion of Shanghai(17ZR1442900)Nanjing Universiry Innovation and Creative Program for PhD candidatc(2016017)Basic Research Project of Shanghai Science and Technology Commission(20JC1416100).
文摘Quantum stochastic phase estimation has many applications in the precise measurement of various physical parameters.Similar to the estimation of a constant phase,there is a standard quantum limit for stochastic phase estimation,which can be obtained with the Mach-Zehnder interferometer and coherent input state.Recently,it has been shown that the stochastic standard quantum limit can be surpassed with nonclassical resources such as squcezed light.However,practical methods to achieve quantum enhancement in the stochastic phase estimation remain largely unexplored.Here we propose a method utilizing the SU(1,1)interferometer and coherent input states to cstimate a stochastic optical phase.As an example,we investigate the Ornstcin-Uhlenback stochastic phase.We analyze the performance of this method for three key estimation problems:prediction,tracking,and smoothing.The results show significant reduction of the mean square error compared with the Mach-Zehnder interferometer under the same photon number flux inside the interferometers.In particular,we show that the method with the SU(1,1)interferometer can achieve fundamental quantum scaling,achieve stochastic Heisenberg scalinga and surpass the precision of the canonical measurement.
基金This project was financially supported as National S&T Major Special Project on Major New Drug Innovation(No.2009zx09103-036)by the National Nature Science Foun-dation of China(No.30572256).
文摘A series of novel phenyl-urea derivatives which can simultaneously activate gluco kinase(GK)and peroxisome proliferator-activated receptorγ(PPARγ)was designed and prepared,and their activation of GK and PPARγ was evaluated.The structure--activity relationships of these compounds are also described.Three compounds showed potent ability to activate both GK and PPARγ.The possible binding mode of one of these compounds with GK and PPARγ were predicted by molecular docking simulation.
基金National Key Research and Development Program of China(2017YFA0303703,2017YFA0303800)National Natural Science Foundation of China(61535009,61575218,61675011,61827820,61975077,91836303)+2 种基金Beijing Nova Program(Z181100006218097)Beijing Municipal Commission of Education(KZ201810005003)Fundamental Research Funds for the Central Universities(020214380068).
文摘Hollow-core fiber(HCF)promises to unify air-borne light propagation and non-line-of-sight transmission,thus holding great potential for versatile photonics-based quantum information applications.The early version of HCF based on photonic-bandgap guidance has not proven itself a reliable quantum channel because of the poor modal purity in both spatial and polarization domains,as well as significant difficulty in fabrication when the wavelength shifts to the visible region.In this work,based on the polarization degree of freedom,we demonstrate high-fidelity(∼0.98)single-photon transmission and distribution of entangled photons over a 36.4 m hollow-core conjoined-tube fiber(CTF)by using commercial silicon single-photon avalanche photodiodes.Our CTF realizes the combined merits of low loss,high spatial modal purity,low polarization degradation,and low chromatic dispersion.We also demonstrate single-photon low-latency(∼99.96%speed of light in vacuum)transmission,paving the way for extensive uses of HCF links in versatile photonics-based quantum information processing.
基金National Key Research and Development Program of China(2017YFA0303703,2018YFA030602)National Natural Science Foundation of China(91836303,61975077,11690032)Fundamental Research Funds for the Central Universities(020214380068)。
文摘As a method to extract information from optical systems,imaging can be viewed as a parameter estimation problem.The fundamental precision in locating one emitter or estimating the separation between two incoherent emitters is bounded below by the multiparameter quantum Cramér-Rao bound(QCRB).Multiparameter QCRB gives an intrinsic bound in parameter estimation.We determine the ultimate potential of quantum-limited imaging for improving the resolution of a far-field,diffraction-limited optical field within the paraxial approximation.We show that the quantum Fisher information matrix(QFIm)in about one emitter’s position is independent on its true value.We calculate the QFIm of two unequal-brightness emitters’relative positions and intensities;the results show that only when the relative intensity and centroids of two-point sources,including longitudinal and transverse directions,are known exactly,the separation in different directions can be estimated simultaneously with finite precision.Our results give the upper bounds on certain far-field imaging technology and will find wide use in applications from microscopy to astrometry.
基金National Key Research and Development Program of China(2017YFA0304002)National Natural Science Foundation of China(61571217,61521001,61801206,11227904)+1 种基金Priority Academic Program Development of Jiangsu Higher Education InstitutionsNanjing University。
文摘Laser communication using photons should consider not only the transmission environment’s effects,but also the performance of the single-photon detector used and the photon number distribution.Photon communication based on the superconducting nanowire single-photon detector(SNSPD)is a new technology that addresses the current sensitivity limitations at the level of single photons in deep space communication.The communication’s bit error rate(BER)is limited by dark noise in the space environment and the photon number distribution with a traditional single-pixel SNSPD,which is unable to resolve the photon number distribution.In this work,an enhanced photon communication method was proposed based on the photon number resolving function of four-pixel array SNSPDs.A simulated picture transmission was carried out,and the error rate in this counting mode can be reduced by 2 orders of magnitude when compared with classical optical communication.However,in the communication mode using photon-enhanced counting,the four-pixel response amplitude for counting was found to restrain the communication rate,and this counting mode is extremely dependent on the incident light intensity through experiments,which limits the sensitivity and speed of the SNSPD array’s performance advantage.Therefore,a BER theoretical calculation model for laser communication was presented using the Bayesian estimation algorithm in order to analyze the selection of counting methods for information acquisition under different light intensities and to make better use of the SNSPD array’s high sensitivity and speed and thus to obtain a lower BER.The counting method and theoretical model proposed in this work refer to array SNSPDs in the deep space field.
基金supported by the Fundamental Research Funds for the Central Universities (WK2060140023, WK2060140022, CX3430000001 and WK2060140024)the Major/Innovative Program of Development Foundation of Hefei Center for Physical Science and Technology (2016FXZY003)the National Natural Science Foundation of China (GG2060140085 and CX2310000097)
文摘Metal chalcogenides (MCs) are significant semiconducting materials possessing a variety of applications in catalysts , thermoelectrics , rewritable memory, thin film transistors (TFTs), and solar cells, usually presenting as solid films. Until now, one can deposit the bulk materials on a substrate by either topdown method such as thermal evaporation or bottom-up deposition from molecular precursors. The latter approach, usually described as solution processing, allows low-energy, low-cost, high-speed and high-throughput manufacturing, and is compatible with a variety of substrates .
基金the National Key Research and Development Program of China(Nos.2017YFA0304100,2016YFA0302700)National Natural Science Foundation of China(Grant Nos.11874344,92065107,61835004,11774335,91536219,11821404)+3 种基金Key Research Program of Frontier Sciences,CAS(No.QYZDY-SSW-SLH003)Anhui Initiative in Quantum Information Technologies(AHY020100,AHY060300)the Fundamental Research Funds for the Central Universities(Grant Nos.WK2030020019,WK2470000026)Science Foundation of the CAS(No.ZDRW-XH-2019-1).
文摘In optical metrological protocols to measure physical quantities,it is,in principle,always beneficial to in crease photon number n to improve measurement precision.However,practical constraints prevent the arbitrary increase of n due to the imperfections of a practical detector,especially when the detector response is dominated by the saturation effect.In this work,we show that a modified weak measurement protocol,namely,biased weak measurement significantly improves the precision of optical metrology in the presence of saturation effect.This method detects an ultra-small fraction of photons while main tains a considerable amount of metrological information.The biased pre-coupling leads to an additi onal reduction of photons in the post-selection and gene rates an extinction point in the spectrum distribution,which is extremely sensitive to the estimated parameter and difficult to be saturated.Therefore,the Fisher information can be persistently enhanced by increasing the photon number.In our magnetic-sensing experiment,biased weak measurement achieves precision approximately one order of magnitude better than those of previously used methods.The proposed method can be applied in various optical measurement schemes to remarkably mitigate the detector saturation effect with low-cost apparatuses.
基金supported by the National Key Research and Development Program of China(Grant Nos.2018YFA0306202 and 2017YFA0303703)National Natural Science Foundation of China(Grant Nos.91836303,61975077,61490711,and 11690032)Fundamental Research Funds for the Central Universities(Grant No.020214380068).
文摘The quantum properties of quantum measurements are indispensable resources in quantum information processing and have drawn extensive research interest.The conventional approach to revealing quantum properties relies on the reconstruction of entire measurement operators by quantum detector tomography.However,many specific properties can be determined by a part of the matrix components of the measurement operators,which makes it possible to simplify the characterization process.We propose a general framework to directly obtain individual matrix elements of the measurement operators by sequentially measuring two noncompatible observables.This method allows us to circumvent the complete tomography of the quantum measurement and extract the required information.We experimentally implement this scheme to monitor the coherent evolution of a general quantum measurement by determining the off-diagonal matrix elements.The investigation of the measurement precision indicates the good feasibility of our protocol for arbitrary quantum measurements.Our results pave the way for revealing the quantum properties of quantum measurements by selectively determining the matrix components of the measurement operators.
