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Multi-Level Image Segmentation Combining Chaotic Initialized Chimp Optimization Algorithm and Cauchy Mutation
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作者 shujing li Zhangfei li +2 位作者 Wenhui Cheng Chenyang Qi linguo li 《Computers, Materials & Continua》 SCIE EI 2024年第8期2049-2063,共15页
To enhance the diversity and distribution uniformity of initial population,as well as to avoid local extrema in the Chimp Optimization Algorithm(CHOA),this paper improves the CHOA based on chaos initialization and Cau... To enhance the diversity and distribution uniformity of initial population,as well as to avoid local extrema in the Chimp Optimization Algorithm(CHOA),this paper improves the CHOA based on chaos initialization and Cauchy mutation.First,Sin chaos is introduced to improve the random population initialization scheme of the CHOA,which not only guarantees the diversity of the population,but also enhances the distribution uniformity of the initial population.Next,Cauchy mutation is added to optimize the global search ability of the CHOA in the process of position(threshold)updating to avoid the CHOA falling into local optima.Finally,an improved CHOA was formed through the combination of chaos initialization and Cauchy mutation(CICMCHOA),then taking fuzzy Kapur as the objective function,this paper applied CICMCHOA to natural and medical image segmentation,and compared it with four algorithms,including the improved Satin Bowerbird optimizer(ISBO),Cuckoo Search(ICS),etc.The experimental results deriving from visual and specific indicators demonstrate that CICMCHOA delivers superior segmentation effects in image segmentation. 展开更多
关键词 Image segmentation image thresholding chimp optimization algorithm chaos initialization Cauchy mutation
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Dechlorination of Trichloroethylene in Groundwater by Nanoscale Bimetallic Fe/Pd Particles 被引量:2
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作者 Tielong li shujing li +1 位作者 Yongchao li Zhaohui JIN 《Journal of Water Resource and Protection》 2009年第2期78-83,共6页
Palladium/iron bimetallic nanoparticles were synthesized using microemulsion method in the water-in-oil (W/O) microemulsion system, which was made up of iso-octane, cetyltrimethyl-ammonium bromide (CTAB), butanol and ... Palladium/iron bimetallic nanoparticles were synthesized using microemulsion method in the water-in-oil (W/O) microemulsion system, which was made up of iso-octane, cetyltrimethyl-ammonium bromide (CTAB), butanol and water and characterized by measuring the conductivity of the solution. Transmission electron microscope (TEM) and energy dispersive X-ray microanalysis (EDX) analysis showed that the av-erage diameter of synthesized palladium/iron bimetallic nanoparticles was less than 80 nm, which was much smaller than the particles produced by the solution method. The palladium/iron bimetallic nanoscale particles produced in the laboratory showed better performance on dechlorinating TCE than the other materials. The nanoscale Fe/Pd particles exhibited high reactivity. When Pd content is 0.5%, the best TCE dechlorination efficiency is achieved within 30min. And Fe/Pd nanoparticles show persistent reaction activity in some sense. 展开更多
关键词 TRICHLOROETHYLENE MICROEMULSION NANOSCALE PD/FE PARTICLES
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PI3 kinase isoform p110δis more important than p110αin KIT signaling in hematopoietic cells
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作者 liANGYING ZHANG SHAOTING ZHANG +4 位作者 ZHAOYANG FAN ZONGYING JIANG ANBU liU shujing li JIANMIN SUN 《BIOCELL》 SCIE 2022年第9期2081-2087,共7页
PI3 kinases are important for KIT signaling and KIT mutants mediated cell transformation.In order to know the difference of PI3 kinase isoforms p110αand p110δin the signaling of wild-type KIT and the often occurred ... PI3 kinases are important for KIT signaling and KIT mutants mediated cell transformation.In order to know the difference of PI3 kinase isoforms p110αand p110δin the signaling of wild-type KIT and the often occurred KIT mutation D816V in hematopoietic malignancy mastocytosis,the predominant PI3 kinase isoform p110δin hematopoietic tissues was knocked out in hematopoietic cells.We found that loss of p110δexpression dramatically inhibits PI3 kinase activation mediated by both wild-type KIT and KIT/D816V.By over expression of p110αin p110δknock out cells,wild-type KIT mediated PI3 kinase activation was not changed while over expression of p110δincreased PI3 kinase activation.Similarly,in KIT/D816V expressing cells without p110δexpression,over expression of p110δbut not p110αrestored PI3 kinase activation.In agreement with the signaling results,cell proliferation,cell survival and cell cycle assay further showed that over expression of p110δbut not p110αin p110δknock out cells increases both wild-type KIT and KIT/D816V mediated cell survival and proliferation.These results suggested that p110δplays a more important role than p110αin KIT signaling and KIT mutant mediated cell transformation in hematopoietic cells. 展开更多
关键词 MASTOCYTOSIS MUTATION Cell transformation
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The role of circadian rhythm in breast cancer 被引量:3
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作者 shujing li Xiang Ao Huijian Wu 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2013年第4期442-450,共9页
The circadian rhythm is an endogenous time keeping system shared by most organisms. The circadian clock is comprised of both peripheral oscillators in most organ tissues of the body and a central pacemaker located in ... The circadian rhythm is an endogenous time keeping system shared by most organisms. The circadian clock is comprised of both peripheral oscillators in most organ tissues of the body and a central pacemaker located in the suprachiasmatic nucleus (SCN) of the central nervous system. The circadian rhythm is crucial in maintaining the normal physiology of the organism including, but not limited to, cell proliferation, cell cycle progression, and cellular metabolism; whereas disruption of the circadian rhythm is closely related to multi-tumorigenesis. In the past several years, studies from different fields have revealed that the genetic or functional disruption of the molecular circadian rhythm has been found in various cancers, such as breast, prostate, and ovarian. In this review, we will investigate and present an overview of the current research on the influence of circadian rhythm regulating proteins on breast cancer. 展开更多
关键词 Circadian rhythm breast cancer circadian proteins CHRONOTHERAPY
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Identification of Crop Diseases Based on Improved Genetic Algorithm and Extreme Learning Machine 被引量:2
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作者 linguo li lijuan Sun +2 位作者 Jian Guo shujing li Ping Jiang 《Computers, Materials & Continua》 SCIE EI 2020年第10期761-775,共15页
As an indispensable task in crop protection,the detection of crop diseases directly impacts the income of farmers.To address the problems of low crop-disease identification precision and detection abilities,a new meth... As an indispensable task in crop protection,the detection of crop diseases directly impacts the income of farmers.To address the problems of low crop-disease identification precision and detection abilities,a new method of detection is proposed based on improved genetic algorithm and extreme learning machine.Taking five different typical diseases with common crops as the objects,this method first preprocesses the images of crops and selects the optimal features for fusion.Then,it builds a model of crop disease identification for extreme learning machine,introduces the hill-climbing algorithm to improve the traditional genetic algorithm,optimizes the initial weights and thresholds of the machine,and acquires the approximately optimal solution.And finally,a data set of crop diseases is used for verification,demonstrating that,compared with several other common machine learning methods,this method can effectively improve the crop-disease identification precision and detection abilities and provide a basis for the identification of other crop diseases. 展开更多
关键词 CROPS disease identification extreme learning machine improved genetic algorithm
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A Multi-Category Brain Tumor Classification Method Bases on Improved ResNet50 被引量:1
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作者 linguo li shujing li Jian Su 《Computers, Materials & Continua》 SCIE EI 2021年第11期2355-2366,共12页
Brain tumor is one of the most common tumors with high mortality.Early detection is of great significance for the treatment and rehabilitation of patients.The single channel convolution layer and pool layer of traditi... Brain tumor is one of the most common tumors with high mortality.Early detection is of great significance for the treatment and rehabilitation of patients.The single channel convolution layer and pool layer of traditional convolutional neural network(CNN)structure can only accept limited local context information.And most of the current methods only focus on the classification of benign and malignant brain tumors,multi classification of brain tumors is not common.In response to these shortcomings,considering that convolution kernels of different sizes can extract more comprehensive features,we put forward the multi-size convolutional kernel module.And considering that the combination of average-pooling with max-pooling can realize the complementary of the high-dimensional information extracted by the two structures,we proposed the dual-channel pooling layer.Combining the two structures with ResNet50,we proposed an improved ResNet50 CNN for the applications in multi-category brain tumor classification.We used data enhancement before training to avoid model over fitting and used five-fold cross-validation in experiments.Finally,the experimental results show that the network proposed in this paper can effectively classify healthy brain,meningioma,diffuse astrocytoma,anaplastic oligodendroglioma and glioblastoma. 展开更多
关键词 Brain tumor convolutional neural network multi-size convolutional kernel module dual-channel pooling layer ResNet50
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Fuzzy Hybrid Coyote Optimization Algorithm for Image Thresholding
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作者 linguo li Xuwen Huang +3 位作者 Shunqiang Qian Zhangfei li shujing li Romany F.Mansour 《Computers, Materials & Continua》 SCIE EI 2022年第8期3073-3090,共18页
In order to address the problems of Coyote Optimization Algorithm in image thresholding,such as easily falling into local optimum,and slow convergence speed,a Fuzzy Hybrid Coyote Optimization Algorithm(here-inafter re... In order to address the problems of Coyote Optimization Algorithm in image thresholding,such as easily falling into local optimum,and slow convergence speed,a Fuzzy Hybrid Coyote Optimization Algorithm(here-inafter referred to as FHCOA)based on chaotic initialization and reverse learning strategy is proposed,and its effect on image thresholding is verified.Through chaotic initialization,the random number initialization mode in the standard coyote optimization algorithm(COA)is replaced by chaotic sequence.Such sequence is nonlinear and long-term unpredictable,these characteristics can effectively improve the diversity of the population in the optimization algorithm.Therefore,in this paper we first perform chaotic initialization,using chaotic sequence to replace random number initialization in standard COA.By combining the lens imaging reverse learning strategy and the optimal worst reverse learning strategy,a hybrid reverse learning strategy is then formed.In the process of algorithm traversal,the best coyote and the worst coyote in the pack are selected for reverse learning operation respectively,which prevents the algorithm falling into local optimum to a certain extent and also solves the problem of premature convergence.Based on the above improvements,the coyote optimization algorithm has better global convergence and computational robustness.The simulation results show that the algorithmhas better thresholding effect than the five commonly used optimization algorithms in image thresholding when multiple images are selected and different threshold numbers are set. 展开更多
关键词 Coyote optimization algorithm image segmentation multilevel thresholding logistic chaotic map hybrid inverse learning strategy
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Magnetic phase diagram of single-layer CrBr_(3)
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作者 Wei Jiang Yue-Fei Hou +2 位作者 shujing li Zhen-Guo Fu Ping Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第12期577-582,共6页
We theoretically provide a magnetic phase diagram for the single-layer(SL)CrBr_(3),which could be effectively tuned by both strain engineering and charge doping in SL-CrBr_(3).Through systematical first-principles cal... We theoretically provide a magnetic phase diagram for the single-layer(SL)CrBr_(3),which could be effectively tuned by both strain engineering and charge doping in SL-CrBr_(3).Through systematical first-principles calculations and Heisenberg model Hamiltonian simulations,three different magnetic phases in SL-CrBr_(3),which are off-plane ferromagnetic,in-plane ferromagnetic and in-plane Neél-antiferromagnetic phases,are found in the strain and charge doping regimes we studied.Furthermore,our results show that higher order Heisenberg exchange parameters and anisotropy exchange parameters should be taken into account for accurately illustrating the magnetic phase transition in SL-CrBr_(3).As a result,we find from the SpinW simulation that the Curie temperature is about T_(c)=38.4 K,which is well consistent with the experimental result 34 K[Nano Lett.193138(2019)].The findings here may be confirmed in future experiments,and may be useful for the potential applications of SL-CrBr_(3)in spintronics field. 展开更多
关键词 magnetic anisotropy single-layer CrBr_(3) Néel-antiferromagnetic phase
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Preparation of Nanoiron by Water-in-Oil (W/O) Microemulsion for Reduction of Nitrate in Groundwater
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作者 Tielong li shujing li +2 位作者 Shuaima WANG Yi AN Zhaohui JIN 《Journal of Water Resource and Protection》 2009年第1期16-21,共6页
Nanometer-sized iron particles with monodispersity and narrow size distribution were synthesized by modi-fied microemulsion system using environment-friendly non-ionic surfactants Span 80 and Tween 60 as mixed surfact... Nanometer-sized iron particles with monodispersity and narrow size distribution were synthesized by modi-fied microemulsion system using environment-friendly non-ionic surfactants Span 80 and Tween 60 as mixed surfactants. The synthesized iron nanoparticles were characterized by using powder X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that the synthesized particles were mainly composed of α-Fe with an average diameter of 80-90 nm. The chemical activity of the obtained iron nanoparticles was evaluated by the denitrification of nitrate in water. On neutral condition, complete denitri-fication of nitrate was achieved by freshly synthesized nanoiron within 30 min. Ammonia was the main product, with good material balance at the end of the reaction. Two possible reaction pathways for nitrate reduction by nanoiron have been proposed in this study. 展开更多
关键词 IRON Nanoparticles MICROEMULSION REDUCTION NITRATE
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Driver Steering Behaviour Modelling Based on Neuromuscular Dynamics and Multi‑Task Time‑Series Transformer
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作者 Yang Xing Zhongxu Hu +5 位作者 Xiaoyu Mo Peng Hang shujing li Yahui liu Yifan Zhao Chen Lv 《Automotive Innovation》 EI CSCD 2024年第1期45-58,共14页
Driver steering intention prediction provides an augmented solution to the design of an onboard collaboration mechanism between human driver and intelligent vehicle.In this study,a multi-task sequential learning frame... Driver steering intention prediction provides an augmented solution to the design of an onboard collaboration mechanism between human driver and intelligent vehicle.In this study,a multi-task sequential learning framework is developed to pre-dict future steering torques and steering postures based on upper limb neuromuscular electromyography signals.The joint representation learning for driving postures and steering intention provides an in-depth understanding and accurate modelling of driving steering behaviours.Regarding different testing scenarios,two driving modes,namely,both-hand and single-right-hand modes,are studied.For each driving mode,three different driving postures are further evaluated.Next,a multi-task time-series transformer network(MTS-Trans)is developed to predict the future steering torques and driving postures based on the multi-variate sequential input and the self-attention mechanism.To evaluate the multi-task learning performance and information-sharing characteristics within the network,four distinct two-branch network architectures are evaluated.Empirical validation is conducted through a driving simulator-based experiment,encompassing 21 participants.The pro-posed model achieves accurate prediction results on future steering torque prediction as well as driving posture recognition for both two-hand and single-hand driving modes.These findings hold significant promise for the advancement of driver steering assistance systems,fostering mutual comprehension and synergy between human drivers and intelligent vehicles. 展开更多
关键词 Driver steering behaviours Neuromuscular dynamics Multi-task learning Sequential transformer Intelligent vehicles
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Effect of Cross-Modal Perceptual Training on Audiovisual Integration in Older Adults
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作者 Hang Ping shujing li +4 位作者 Canting Xiong Yan li Xiaoyu li Xiaofeng Fang Yan li 《Open Journal of Therapy and Rehabilitation》 2024年第4期347-355,共9页
Background: Previous studies have demonstrated the plasticity of perceptual sensitivity and compensatory mechanisms of audiovisual integration (AVI) in older adults. However, the impact of perceptual training on audio... Background: Previous studies have demonstrated the plasticity of perceptual sensitivity and compensatory mechanisms of audiovisual integration (AVI) in older adults. However, the impact of perceptual training on audiovisual integrative abilities remains unclear. Methods: This study randomly assigned 40 older adults to either a training or control group. The training group underwent a five-day audiovisual perceptual program, while the control group received no training. Participants completed simultaneous judgment (SJ) and audiovisual detection tasks before and after training. Results: Findings indicated improved perceptual sensitivity to audiovisual synchrony in the training group, with AVI significantly higher post-test compared to pre-test (9.95% vs. 13.87%). No significant change was observed in the control group (9.61% vs. 10.77%). Conclusion: These results suggested that cross-modal perceptual training might be an effective candidate cognitive intervention to ease the dysfunction of unimodal sensory. 展开更多
关键词 Perceptual Training Audiovisual Integration Simultaneous Judgement Task Audiovisual Detection Task Older
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MZF1(Myeloid Zinc Finger 1)activates transcriptional activity of p53 and suppresses breast cancer cell proliferation via acetyltransferase PCAF(P300/CBP associated factor)
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作者 Bowen li shujing li +6 位作者 Xiaoxia Shi Yini Zhang Zhiqiang Xin Yuxi Yang Binggong Zhao Ping Ren Huijian Wu 《Genes & Diseases》 SCIE CSCD 2023年第5期1775-1778,共4页
p53 is an important tumor suppressor gene.The p53 pathway is activated in response to cellular stress stimulation.However,in more than 50%of breast cancers,p53 is mutated or inactivated,which permits cancer growth.1 A... p53 is an important tumor suppressor gene.The p53 pathway is activated in response to cellular stress stimulation.However,in more than 50%of breast cancers,p53 is mutated or inactivated,which permits cancer growth.1 Although a large number of co-regulators of p53 have been identified,the integrated molecular network of p53 and the key co-factors that could transactivate p53 remain unclear.2 Myeloid Zinc Finger 1(MZF1),a member of the SCAN-ZFP(SCAN-Zinc finger protein)family,has been involved in the occurrence and development of various types of malignant tumors,including breast cancer.3 However,the exact mechanism of action remains unclear.Our study aims to investigate the cross-regulatory loop between MZF1 and p53 in breast cancer cells. 展开更多
关键词 SCAN Zinc P53
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CHD4-induced up-regulation of ERα activity contributes to breast cancer progression
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作者 Aman Sattout Xiaomin Yu +5 位作者 Zhuo Sun Yanan li Yulin li shujing li Wei Huo Huijian Wu 《Genes & Diseases》 SCIE CSCD 2024年第3期132-135,共4页
The estrogen signaling system is a crucial regulator of metabolicandphysiologicalprocesses.However,abnormal activation of estrogen signaling may play a role in breast cancer initiation and progression.Crucial to this ... The estrogen signaling system is a crucial regulator of metabolicandphysiologicalprocesses.However,abnormal activation of estrogen signaling may play a role in breast cancer initiation and progression.Crucial to this pathway is the interaction between estrogen receptor alpha(ERa)and various co-transcription activators.1 Although numerous studies have investigated ER coregulators,the protein-protein interaction networks of ERa are not fully understood.Recent research has shown that high chromodomain helicase DNA-binding 4(CHD4)expression is linked to poor prognosis in various cancers.2,?In this study,we demonstrated that both CHD4 and ERαcontribute to breast cancer progression while providing evidence of the regulatory processes and functional interplay between these two proteins. 展开更多
关键词 BREAST CANCER ERΑ
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Phosphorylation Promotes the Accumulation of PERIOD Protein Foci
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作者 Mengna li shujing li Luoying Zhang 《Research》 SCIE EI CSCD 2024年第1期59-69,共11页
Circadian clock drives the 24-h rhythm in our behavior and physiology.The molecular clock consists of a series of transcriptional/translational feedback loops operated by a number of clock genes.A very recent study re... Circadian clock drives the 24-h rhythm in our behavior and physiology.The molecular clock consists of a series of transcriptional/translational feedback loops operated by a number of clock genes.A very recent study reported that the clock protein PERIOD(PER)is organized into discrete foci at the nuclear envelope in fly circadian neurons,which is believed to be important for controlling the subcellular localization of clock genes.Loss of inner nuclear membrane protein lamin B receptor(LBR)leads to disruption of these foci,but how they are regulated is yet unknown.Here,we found that PER foci are likely phase-separated condensates,the formation of which is mediated by intrinsically disordered region in PER.Phosphorylation promotes the accumulation of these foci.Protein phosphatase 2A,which is known to dephosphorylate PER,hampers the accumulation of the foci.On the other hand,the circadian kinase DOUBLETIME(DBT)which phosphorylates PER enhances the accumulation of the foci.LBR likely facilitates PER foci accumulation by destabilizing the catalytic subunit of protein phosphatase 2A,MICROTUBULE STAR(MTS).In conclusion,here,we demonstrate a key role for phosphorylation in promoting the accumulation of PER foci,while LBR modulates this process by impinging on the circadian phosphatase MTS. 展开更多
关键词 CONCLUSION SEPARATED TRANSLATIONAL
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Progress in the mechanism and targeted drug therapy for COPD 被引量:32
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作者 Cuixue Wang Jiedong Zhou +4 位作者 Jinquan Wang shujing li Atsushi Fukunaga Junji Yodoi Hai Tian 《Signal Transduction and Targeted Therapy》 SCIE CSCD 2020年第1期359-378,共20页
Chronic obstructive pulmonary disease(COPD)is emphysema and/or chronic bronchitis characterised by long-term breathing problems and poor airflow.The prevalence of COPD has increased over the last decade and the drugs ... Chronic obstructive pulmonary disease(COPD)is emphysema and/or chronic bronchitis characterised by long-term breathing problems and poor airflow.The prevalence of COPD has increased over the last decade and the drugs most commonly used to treat it,such as glucocorticoids and bronchodilators,have significant therapeutic effects;however,they also cause side effects,including infection and immunosuppression.Here we reviewed the pathogenesis and progression of COPD and elaborated on the effects and mechanisms of newly developed molecular targeted COPD therapeutic drugs.Among these new drugs,we focussed on thioredoxin(Trx).Trx effectively prevents the progression of COPD by regulating redox status and protease/anti-protease balance,blocking the NF-κB and MAPK signalling pathways,suppressing the activation and migration of inflammatory cells and the production of cytokines,inhibiting the synthesis and the activation of adhesion factors and growth factors,and controlling the cAMP-PKA and PI3K/Akt signalling pathways.The mechanism by which Trx affects COPD is different from glucocorticoid-based mechanisms which regulate the inflammatory reaction in association with suppressing immune responses.In addition,Trx also improves the insensitivity of COPD to steroids by inhibiting the production and internalisation of macrophage migration inhibitory factor(MIF).Taken together,these findings suggest that Trx may be the ideal drug for treating COPD. 展开更多
关键词 DRUGS TARGETED INHIBITING
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Generation of polarization-entangled photon pairs in a cold atomic ensemble 被引量:3
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作者 Yuelong Wu shujing li +3 位作者 Wei Ge Zhongxiao Xu Long Tian Hai Wang 《Science Bulletin》 SCIE EI CAS CSCD 2016年第4期302-306,共5页
We report an experimental generation of polarization-entangled photon pairs in a cold atomic ensemble. A single Stokes photon and one spin-wave excitation are simultaneously created via spontaneous Raman scattering. T... We report an experimental generation of polarization-entangled photon pairs in a cold atomic ensemble. A single Stokes photon and one spin-wave excitation are simultaneously created via spontaneous Raman scattering. The spin-wave excitation is then converted into an anti-Stokes photon via an electromagnetic-induced-transparency reading process. The measured cross-correlation functions between the Stokes and anti-Stokes photons for two orthogonal polarizations are -75 and 74, respectively, at a generation rate of the photon pair of -60/s. Based on such correlations, we obtain polarization-entangled photon pairs, whose Bell parameter is S = 2.77 4- 0.01, violating Bell-CHSH inequality by -77 standard deviations. The presented polarization-entangled photon source has high entanglement degree and fast generation rate, which will promise us to apply it in future quantum repeater. 展开更多
关键词 Polarization-entangled photon pairsSpontaneous Raman scattering Cold atomicensemble Cross-correlation function Bellparameter Spin-wave excitation
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De Haas–van Alphen study on three-dimensional topological semimetal pyrite PtBi2
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作者 Wenshuai Gao Xiangde Zhu +9 位作者 Jin Hu shujing li Fawei Zheng Hongwei Zhang Min Wu Guolin Zheng Ning Hao Ping Zhang Wei Ning Mingliang Tian 《Science Bulletin》 SCIE EI CAS CSCD 2019年第20期1496-1501,共6页
We present the systematic de Haas–van Alphen(d Hv A) quantum oscillations studies on the recently discovered topological Dirac semimetal pyrite PtBi2 single crystals. Remarkable d Hv A oscillations are emerged at a l... We present the systematic de Haas–van Alphen(d Hv A) quantum oscillations studies on the recently discovered topological Dirac semimetal pyrite PtBi2 single crystals. Remarkable d Hv A oscillations are emerged at a low field about 1.5 T. From the analyses of the d Hv A oscillations, we extract the high quantum mobilities, light effective masses and phase shift factors for the Dirac fermions in pyrite PtBi2. From the angular dependence of the d Hv A oscillations, we map out the topology of the Fermi surface.Furthermore, we identify two additional oscillation frequencies that are not probed by the Sd H oscillations, which provides us with opportunities to further understand its Fermi surface topology. 展开更多
关键词 TOPOLOGICAL SEMIMETAL PYRITE PtBi2 DE Haas–van Alphen effect FERMI surface topology
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Ba3LaNa(PO4)3F:Tm^3+,Dy^3+:A tunable blue-white color emitting phosphor via energy transfer for UV white LEDs
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作者 Dingdian Xu Wei Zhou +1 位作者 shujing li Dongsheng Bai 《Chinese Chemical Letters》 SCIE CAS CSCD 2020年第2期575-578,共4页
A series of Tm^3+/Dy^3+co-doped Ba3 LaNa(PO4)3 F(BLNPF) phosphors were synthesized successfully via a high-temperature solid-reaction,and luminescence properties were investigated.Upon near violet excitation,BLNPF:Tm^... A series of Tm^3+/Dy^3+co-doped Ba3 LaNa(PO4)3 F(BLNPF) phosphors were synthesized successfully via a high-temperature solid-reaction,and luminescence properties were investigated.Upon near violet excitation,BLNPF:Tm^3+,Dy^3+ phosphors exhibit Tm^3+:^1D2-^3 F4 and Dy^3+:^4 F(9/2)-^6 HJ(J=15/2,13/2,11/2)transitions with diffe rent luminescence intensity.The emitting color of the obtained products was found to shift from blue to white as a result of efficient energy transfer(ET) from Tm^3+to Dy^3+ions.According to photoluminescence emission intensity,the positive effect of activator on ET efficiency was calculated and the maximum ET efficiency was found around 72.6% with Dy^3+ concentration was 0.04.By means of Dexter's theoretical model,furthermore,dipole-dipole interaction was confirmed as the mechanism of energy transfer from Tm^3+ to Dy^3+ ions.The results suggested that BLNPF:Tm^3+,Dy^3+ phosphor might be a promising single-phased white-light-emitting phosphor for UV white-light LED. 展开更多
关键词 PHOSPHORS Ba3LaNa(PO4)3F Luminescence Energy transfer White light
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