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Glycyrrhiza Flavonoids Promote Osteoblast Proliferation and Differentiation by Activating Runx2 via the PI3K/AKT Signaling Pathway
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作者 CHU Hongdan LIANG Zheng +4 位作者 XU Jingru WANG Zhenhua LI Gang GAN Jing XU Bo 《食品科学》 北大核心 2025年第20期188-198,共11页
In order to clarify the mechanism of action of licorice flavonoids in alleviating bone loss caused by osteoporosis,this study compared the effects of four glycyrrhiza flavonoids,naringenin,liquiritigenin,isoliquiritig... In order to clarify the mechanism of action of licorice flavonoids in alleviating bone loss caused by osteoporosis,this study compared the effects of four glycyrrhiza flavonoids,naringenin,liquiritigenin,isoliquiritigenin,and licochalcone A,on osteogenic differentiation and mineralization by molecular docking simulation,alkaline phosphatase(ALP)activity and osteocalcin(OCN)content assays,and Runt-related transcription factor 2(Runx2)expression,and explored their potential molecular mechanisms.The results of molecular docking showed that the docking score of liquiritigenin with the estrogen receptor(ER)was the highest.All four flavonoids up-regulated ALP activity and OCN concentration in MC3T3-E1 cells,thereby elevating the mineralization level,among which liquiritigenin was the most effective.Moreover,treatment with a phosphatidylinositol-3-kinase(PI3K)inhibitor(LY294002)inhibited liquiritigenin from inducing increased phosphorylation levels in the PI3K/protein kinase B(AKT)signaling pathway and up-regulation of Runx2 expression,suggesting that PI3K and AKT were involved in osteogenic action.Liquiritigenin reversed bone mineral density loss in a zebrafish osteoporosis model.These findings suggest that liquiritigenin has the most significant osteogenic effect among the four estrogen-like flavonoids,stimulating osteoblast differentiation and bone mineralization through the activation of Runx2 via the PI3K/AKT signaling pathways.In conclusion,this study highlights the great potential of liquiritigenin for preventing and treating osteoporosis. 展开更多
关键词 MC3T3-E1 cells LIQUIRITIGENIN OSTEOGENESIS phosphatidylinositol-3-kinase/protein kinase B signaling pathway zebrafish
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Low-frequency signal generation in space based on high-frequency electric-antenna array and Doppler effect
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作者 CUI Anjing LI Daojing +6 位作者 WU Jiang GAO Jinghan ZHOU Kai HU Chufeng WU Shumei SHI Danni LI Guang 《Journal of Systems Engineering and Electronics》 2025年第1期24-36,共13页
Low-frequency signals have been proven valuable in the fields of target detection and geological exploration.Nevertheless,the practical implementation of these signals is hindered by large antenna diameters,limiting t... Low-frequency signals have been proven valuable in the fields of target detection and geological exploration.Nevertheless,the practical implementation of these signals is hindered by large antenna diameters,limiting their potential applications.Therefore,it is imperative to study the creation of lowfrequency signals using antennas with suitable dimensions.In contrast to conventional mechanical antenna techniques,our study generates low-frequency signals in the spatial domain utilizing the principle of the Doppler effect.We also defines the antenna array architecture,the timing sequency,and the radiating element signal waveform,and provides experimental prototypes including 8/64 antennas based on earlier research.In the conducted experiments,121 MHz,40 MHz,and 10 kHz composite signals are generated by 156 MHz radiating element signals.The composite signal spectrum matches the simulations,proving our low-frequency signal generating method works.This holds significant implications for research on generating low-frequency signals with small-sized antennas. 展开更多
关键词 frequency conversion array signal processing experimental verification Doppler effect
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Modulated-unlimited sampling scheme and large dynamic range single carrier signals receiving in ultra-wideband frequency space
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作者 Zhaoyang Qiu Pei Wang Chenpu Li 《Defence Technology(防务技术)》 2025年第9期234-245,共12页
Large dynamic range and ultra-wideband receiving abilities are significant for many receivers. With these abilities, receivers can obtain signals with different power in ultra-wideband frequency space without informat... Large dynamic range and ultra-wideband receiving abilities are significant for many receivers. With these abilities, receivers can obtain signals with different power in ultra-wideband frequency space without information loss. However, conventional receiving scheme is hard to have large dynamic range and ultra-wideband receiving simultaneously because of the analog-to-digital converter(ADC) dynamic range and sample rate limitations. In this paper, based on the modulated sampling and unlimited sampling, a novel receiving scheme is proposed to achieve large dynamic range and ultra-wideband receiving. Focusing on the single carrier signals, the proposed scheme only uses a single self-rest ADC(SR-ADC) with low sample rate, and it achieves large dynamic range and ultra-wideband receiving simultaneously. Two receiving scenarios are considered, and they are cooperative strong signal receiving and non-cooperative strong/weak signals receiving. In the cooperative receiving scenario, an improved fast recovery method is proposed to obtain the modulated sampling output. In the non-cooperative receiving scenario, the strong and weak signals with different carrier frequencies are considered, and the signal processing method can recover and estimate each signal. Simulation results show that the proposed scheme can realize large dynamic range and ultra-wideband receiving simultaneously when the input signal-to-noise(SNR) ratio is high. 展开更多
关键词 Modulated-unlimited sampling Ultra-wideband receiving Large dynamic range signal recovery Parameter estimation
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High resolution range profile analysis based on multicarrier phase-coded waveforms of OFDM radar 被引量:5
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作者 Kai Huo Bin Deng Yongxiang Liu Weidong Jiang Junjie Mao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第3期421-427,共7页
Orthogonal frequency division multiplexing(OFDM) radar with multicarrier phase-coded waveforms has been recently introduced to achieve high range resolution.The conventional method for obtaining the high resolution ... Orthogonal frequency division multiplexing(OFDM) radar with multicarrier phase-coded waveforms has been recently introduced to achieve high range resolution.The conventional method for obtaining the high resolution range profile(HRRP) is based on matched filters.A method of synthesizing HRRP based on the fast Fourier transform(FFT) and decoding is proposed.The mathematical expressions of HRRP are derived by assuming an elementary scenario of point-scattering targets.Based on the characteristic of OFDM multicarrier signals,it mainly analyzes the influence on HRRP exerted by several factors,such as velocity compensation errors,the sampling frequency offset,and so on.The conclusions are significant for the design of the OFDM imaging radar.Finally,the simulation results demonstrate the validity of the conclusions. 展开更多
关键词 orthogonal frequency division multiplexing(OFDM) high resolution range profile(HRRP) MULTICARRIER phase-coded frequency offset.
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Downregulation of MUC1 Inhibits Proliferation and Promotes Apoptosis by Inactivating NF-κB Signaling Pathway in Human Nasopharyngeal Carcinoma 被引量:1
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作者 WU Shou-Wu LIN Shao-Kun +11 位作者 NIAN Zhong-Zhu WANG Xin-Wen LIN Wei-Nian ZHUANG Li-Ming WU Zhi-Sheng HUANG Zhi-Wei WANG A-Min GAO Ni-Li CHEN Jia-Wen YUAN Wen-Ting LU Kai-Xian LIAO Jun 《生物化学与生物物理进展》 SCIE CAS CSCD 北大核心 2024年第9期2182-2193,共12页
Objective To investigate the effect of mucin 1(MUC1)on the proliferation and apoptosis of nasopharyngeal carcinoma(NPC)and its regulatory mechanism.Methods The 60 NPC and paired para-cancer normal tissues were collect... Objective To investigate the effect of mucin 1(MUC1)on the proliferation and apoptosis of nasopharyngeal carcinoma(NPC)and its regulatory mechanism.Methods The 60 NPC and paired para-cancer normal tissues were collected from October 2020 to July 2021 in Quanzhou First Hospital.The expression of MUC1 was measured by real-time quantitative PCR(qPCR)in the patients with PNC.The 5-8F and HNE1 cells were transfected with siRNA control(si-control)or siRNA targeting MUC1(si-MUC1).Cell proliferation was analyzed by cell counting kit-8 and colony formation assay,and apoptosis was analyzed by flow cytometry analysis in the 5-8F and HNE1 cells.The qPCR and ELISA were executed to analyze the levels of TNF-αand IL-6.Western blot was performed to measure the expression of MUC1,NFкB and apoptosis-related proteins(Bax and Bcl-2).Results The expression of MUC1 was up-regulated in the NPC tissues,and NPC patients with the high MUC1 expression were inclined to EBV infection,growth and metastasis of NPC.Loss of MUC1 restrained malignant features,including the proliferation and apoptosis,downregulated the expression of p-IкB、p-P65 and Bcl-2 and upregulated the expression of Bax in the NPC cells.Conclusion Downregulation of MUC1 restrained biological characteristics of malignancy,including cell proliferation and apoptosis,by inactivating NF-κB signaling pathway in NPC. 展开更多
关键词 mucin 1 nasopharyngeal carcinoma NF-κB signaling pathway PROLIFERATION APOPTOSIS
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Detection method of forward-scatter signal based on Rényi entropy 被引量:2
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作者 ZHENG Yuqing AI Xiaofeng +2 位作者 YANG Yong ZHAO Feng XIAO Shunping 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第4期865-873,共9页
The application scope of the forward scatter radar(FSR)based on the Global Navigation Satellite System(GNSS)can be expanded by improving the detection capability.Firstly,the forward-scatter signal model when the targe... The application scope of the forward scatter radar(FSR)based on the Global Navigation Satellite System(GNSS)can be expanded by improving the detection capability.Firstly,the forward-scatter signal model when the target crosses the baseline is constructed.Then,the detection method of the for-ward-scatter signal based on the Rényi entropy of time-fre-quency distribution is proposed and the detection performance with different time-frequency distributions is compared.Simula-tion results show that the method based on the smooth pseudo Wigner-Ville distribution(SPWVD)can achieve the best perfor-mance.Next,combined with the geometry of FSR,the influence on detection performance of the relative distance between the target and the baseline is analyzed.Finally,the proposed method is validated by the anechoic chamber measurements and the results show that the detection ability has a 10 dB improvement compared with the common constant false alarm rate(CFAR)detection. 展开更多
关键词 forward scatter radar(FSR) Global Navigation Satellite System(GNSS) time-frequency distribution Rényi entropy signal detection
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Special Section on High-Dimensional Signal Processing
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《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第3期F0002-F0002,共1页
Massive amounts of data are acquired in modern and future information technology industries such as communication,radar,and remote sensing.The presence of large dimensionality and size in these data offers new opportu... Massive amounts of data are acquired in modern and future information technology industries such as communication,radar,and remote sensing.The presence of large dimensionality and size in these data offers new opportunities to enhance the performance of signal processing in such applications and even motivate new ones.However,the curse of dimensionality is always a challenge when processing such high-dimensional signals.In practical tasks,high-dimensional signals need to be acquired,processed,and analyzed with high accuracy,robustness,and computational efficiency.This special section aims to address these challenges,where articles attempt to develop new theories and methods that are best suited to the high dimensional nature of the signals involved,and explore modern and emerging applications in this area. 展开更多
关键词 signal MASSIVE dimensionality
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The in-depth transmission and reception process of the factors influencing review helpfulness from the signaling timeline perspective
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作者 Mohan Wang Fei Wan +1 位作者 Jiaying Zhang Songyun Xia 《中国科学技术大学学报》 CSCD 北大核心 2024年第10期35-50,I0006,I0007,共18页
Many existing studies have considered the factors influencing review helpfulness,mainly focusing on reviewer impact,review informativeness,and managerial response,based on signaling theory.However,previous studies hav... Many existing studies have considered the factors influencing review helpfulness,mainly focusing on reviewer impact,review informativeness,and managerial response,based on signaling theory.However,previous studies have simply regarded these factors as independent signals,thus ignoring their in-depth transmission and reception processes.The conclusions about the impact of reviewers on review helpfulness are also inconsistent due to the inaccurate measure-ment of variables.To fill the above gaps,we followed the signaling timeline theoretical framework used in signaling the-ory and employed a bootstrapping analysis to examine how reviewer impact,review informativeness,and hotel manageri-al responses interact to influence review helpfulness.In this study,we used a unique dataset that included official labels from one leading online travel agency.The results show that reviewer impact may affect review helpfulness sequentially through review informativeness and hotel managerial response.Furthermore,by using official labels,both reviewer expert-ise and reviewer experience significantly affect review helpfulness.Finally,we discussed the theoretical and practical im-plications of these findings. 展开更多
关键词 signaling timeline review helpfulness reviewer impact review informativeness managerial response
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Automatic modulation recognition of radiation source signals based on two-dimensional data matrix and improved residual neural network
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作者 Guanghua Yi Xinhong Hao +3 位作者 Xiaopeng Yan Jian Dai Yangtian Liu Yanwen Han 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期364-373,共10页
Automatic modulation recognition(AMR)of radiation source signals is a research focus in the field of cognitive radio.However,the AMR of radiation source signals at low SNRs still faces a great challenge.Therefore,the ... Automatic modulation recognition(AMR)of radiation source signals is a research focus in the field of cognitive radio.However,the AMR of radiation source signals at low SNRs still faces a great challenge.Therefore,the AMR method of radiation source signals based on two-dimensional data matrix and improved residual neural network is proposed in this paper.First,the time series of the radiation source signals are reconstructed into two-dimensional data matrix,which greatly simplifies the signal preprocessing process.Second,the depthwise convolution and large-size convolutional kernels based residual neural network(DLRNet)is proposed to improve the feature extraction capability of the AMR model.Finally,the model performs feature extraction and classification on the two-dimensional data matrix to obtain the recognition vector that represents the signal modulation type.Theoretical analysis and simulation results show that the AMR method based on two-dimensional data matrix and improved residual network can significantly improve the accuracy of the AMR method.The recognition accuracy of the proposed method maintains a high level greater than 90% even at -14 dB SNR. 展开更多
关键词 Automatic modulation recognition Radiation source signals Two-dimensional data matrix Residual neural network Depthwise convolution
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伪码调相-线性调频的低轨导航信号波形及捕获性能 被引量:1
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作者 林红磊 耿敏嫣 +3 位作者 付栋 欧钢 肖伟 马明 《电子与信息学报》 北大核心 2025年第1期211-222,共12页
低轨导航星座卫星数量多,信号多普勒频偏大,接收机冷启动搜索空间巨大,捕获速度慢,该文提出一种伪码调相-线性调频(CSK-LFM)的导航信号波形,线性调频提高信号的多普勒容限,不同伪码相位实现不同卫星的多址播发,可以极大压缩卫星号、时... 低轨导航星座卫星数量多,信号多普勒频偏大,接收机冷启动搜索空间巨大,捕获速度慢,该文提出一种伪码调相-线性调频(CSK-LFM)的导航信号波形,线性调频提高信号的多普勒容限,不同伪码相位实现不同卫星的多址播发,可以极大压缩卫星号、时延、多普勒3维搜索空间,加快了捕获信号捕获速度。仿真和实验结果表明,当信号强度为40 dBHz时,采用CSK-LFM调制的导航信号,其捕获性能比同等条件下的传统直接扩频序列(DSSS)调制的导航信号高1 dB左右,且信号搜索空间可降低为直接扩频序列调制的1/10。 展开更多
关键词 低轨导航信号 线性调频 CSK调制 信号捕获
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Impact of correlated private signals on continuous-time insider trading
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作者 ZHOU Yonghui XIAO Kai 《运筹学学报(中英文)》 CSCD 北大核心 2024年第3期97-107,共11页
A model of continuous-time insider trading in which a risk-neutral in-sider possesses two imperfect correlated signals of a risky asset is studied.By conditional expectation theory and filtering theory,we first establ... A model of continuous-time insider trading in which a risk-neutral in-sider possesses two imperfect correlated signals of a risky asset is studied.By conditional expectation theory and filtering theory,we first establish three lemmas:normal corre-lation,equivalent pricing and equivalent profit,which can guarantee to turn our model into a model with insider knowing full information.Then we investigate the impact of the two correlated signals on the market equilibrium consisting of optimal insider trading strategy and semi-strong pricing rule.It shows that in the equilibrium,(1)the market depth is constant over time;(2)if the two noisy signals are not linerly correlated,then all private information of the insider is incorporated into prices in the end while the whole information on the asset value can not incorporated into prices in the end;(3)if the two noisy signals are linear correlated such that the insider can infer the whole information of the asset value,then our model turns into a model with insider knowing full information;(4)if the two noisy signals are the same then the total ex ant profit of the insider is increasing with the noise decreasing,while down to O as the noise going up to infinity;(5)if the two noisy signals are not linear correlated then with one noisy signal fixed,the total ex ante profit of the insider is single-peaked with a unique minimum with respect to the other noisy signal value,and furthermore as the noisy value going to O it gets its maximum,the profit in the case that the real value is observed. 展开更多
关键词 continuous-time insider trading risk neutral private correlated signals linear bayesian equilibrium market depth residual information
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Low-complexity signal detection for massive MIMO systems via trace iterative method
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作者 IMRAN A.Khoso ZHANG Xiaofei +2 位作者 ABDUL Hayee Shaikh IHSAN A.Khoso ZAHEER Ahmed Dayo 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第3期549-557,共9页
Linear minimum mean square error(MMSE)detection has been shown to achieve near-optimal performance for massive multiple-input multiple-output(MIMO)systems but inevitably involves complicated matrix inversion,which ent... Linear minimum mean square error(MMSE)detection has been shown to achieve near-optimal performance for massive multiple-input multiple-output(MIMO)systems but inevitably involves complicated matrix inversion,which entails high complexity.To avoid the exact matrix inversion,a considerable number of implicit and explicit approximate matrix inversion based detection methods is proposed.By combining the advantages of both the explicit and the implicit matrix inversion,this paper introduces a new low-complexity signal detection algorithm.Firstly,the relationship between implicit and explicit techniques is analyzed.Then,an enhanced Newton iteration method is introduced to realize an approximate MMSE detection for massive MIMO uplink systems.The proposed improved Newton iteration significantly reduces the complexity of conventional Newton iteration.However,its complexity is still high for higher iterations.Thus,it is applied only for first two iterations.For subsequent iterations,we propose a novel trace iterative method(TIM)based low-complexity algorithm,which has significantly lower complexity than higher Newton iterations.Convergence guarantees of the proposed detector are also provided.Numerical simulations verify that the proposed detector exhibits significant performance enhancement over recently reported iterative detectors and achieves close-to-MMSE performance while retaining the low-complexity advantage for systems with hundreds of antennas. 展开更多
关键词 signal detection LOW-COMPLEXITY linear minimum mean square error(MMSE) massive multiple-input multiple-output(MIMO) trace iterative method(TIM)
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Blind radar signal separation algorithm based on third-order degree of cyclostationarity criteria
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作者 FAN Xiangyu LIU Bin +2 位作者 DONG Danna CHEN You WANG Yuancheng 《Journal of Systems Engineering and Electronics》 CSCD 2024年第6期1441-1453,共13页
Separation and recognition of radar signals is the key function of modern radar reconnaissance,which is of great sig-nificance for electronic countermeasures and anti-countermea-sures.In order to improve the ability o... Separation and recognition of radar signals is the key function of modern radar reconnaissance,which is of great sig-nificance for electronic countermeasures and anti-countermea-sures.In order to improve the ability of separating mixed signals in complex electromagnetic environment,a blind source separa-tion algorithm based on degree of cyclostationarity(DCS)crite-rion is constructed in this paper.Firstly,the DCS criterion is con-structed by using the cyclic spectrum theory.Then the algo-rithm flow of blind source separation is designed based on DCS criterion.At the same time,Givens matrix is constructed to make the blind source separation algorithm suitable for multiple sig-nals with different cyclostationary frequencies.The feasibility of this method is further proved.The theoretical and simulation results show that the algorithm can effectively separate and re-cognize common multi-radar signals. 展开更多
关键词 blind signal separation cyclostationary frequency Givens matrix degree of cyclostationarity(DCS)blind source separation algorithm
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基于Nrf2/HO-1和NF-κB信号通路探讨清化止泻方对腹泻型肠易激综合征大鼠巨噬细胞极化的影响 被引量:2
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作者 黄华 王永通 +2 位作者 丁旭枫 蒋捷 季利江 《中成药》 北大核心 2025年第2期438-445,共8页
目的探讨清化止泻方对腹泻型肠易激综合征(IBS-D)大鼠的改善作用及其对M1/M2型巨噬细胞极化的影响。方法SD大鼠随机分为空白组、模型组、匹维溴铵组(20 mg/kg)和清化止泻方低、高剂量组(13.64、27.29 g/kg),每组10只,采用慢性束缚应激... 目的探讨清化止泻方对腹泻型肠易激综合征(IBS-D)大鼠的改善作用及其对M1/M2型巨噬细胞极化的影响。方法SD大鼠随机分为空白组、模型组、匹维溴铵组(20 mg/kg)和清化止泻方低、高剂量组(13.64、27.29 g/kg),每组10只,采用慢性束缚应激加番泻叶水煎剂灌胃法构建IBS-D大鼠模型,各组给予相应剂量药物14 d。观察各组大鼠进食状况、粪便性状和体质量变化;腹部撤离反射(AWR)测定大鼠肠疼痛敏感性;HE染色观察结肠黏膜组织病理学;TUNEL染色观察结肠组织细胞凋亡情况;免疫荧光染色检测大鼠结肠组织ZO-1、Occludin、Nrf2蛋白表达;流式细胞术检测肠系膜淋巴结中M1型和M2巨噬细胞比值;Western blot法检测结肠组织Nrf2、HO-1、p-IκBα、p-P65蛋白表达。结果与模型组比较,清化止泻方各剂量组大鼠体质量、AWR痛觉阈值升高(P<0.05,P<0.01);结肠组织结构基本完整,上皮细胞排列整齐,未见大量细胞变性脱落;结肠组织ZO-1、Occludin蛋白荧光强度增强(P<0.05,P<0.01);结肠组织细胞凋亡率降低(P<0.05,P<0.01);肠系膜淋巴结巨噬细胞向M2极化(P<0.05,P<0.01);结肠组织Nrf2、HO-1蛋白表达升高(P<0.05,P<0.01),p-IκBα/IκBα和p-P65/P65蛋白表达降低(P<0.05,P<0.01)。结论清化止泻方可改善IBS-D大鼠肠上皮黏膜屏障功能,其作用可能与激活Nrf2/HO-1信号通路,抑制NF-κB信号通路活化,调控巨噬细胞向M2极化有关。 展开更多
关键词 清化止泻方 腹泻型肠易激综合征 巨噬细胞 巨噬细胞极化 Nrf2/HO-1信号通路 NF-ΚB信号通路
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基于国产DSP和FPGA的高速信号处理板硬件电路设计 被引量:1
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作者 孙艳萍 边晨通 +1 位作者 屈文涛 宋淑军 《仪表技术与传感器》 北大核心 2025年第5期33-38,共6页
针对目前高速信号处理板多选用国外芯片,国产化程度较低的问题,文中基于DSP和FPGA芯片完成了高速信号处理板国产化设计。首先考虑高速信号处理板应用于人工智能、图像处理等领域,是一种高精度和复杂运算的场景,因此选择DSP芯片FTDOC35BB... 针对目前高速信号处理板多选用国外芯片,国产化程度较低的问题,文中基于DSP和FPGA芯片完成了高速信号处理板国产化设计。首先考虑高速信号处理板应用于人工智能、图像处理等领域,是一种高精度和复杂运算的场景,因此选择DSP芯片FTDOC35BB_FT_M6678为主设计信号处理模块,选择FPGA芯片FMQL45T900为主设计控制单元模块;然后在CANDENCE软件中进一步采用分布式设计硬件电路,完成了高速信号接口模块、DDR3存储模块、EMIF模块的电路设计;最后使用CCS5.5集成开发环境对高速信号处理板各个接口及外设进行了测试。测试指标均达到要求,证明该高速信号处理板国产化设计切实可行,加速了高速信号处理板的国产化进程。 展开更多
关键词 国产化 FPGA DSP 高速信号
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巨噬细胞极化对血管平滑肌细胞PI3K/Akt/mTOR信号通路的影响 被引量:1
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作者 冯莹 张妍 +3 位作者 雷杰 刘娟 方勇 贺立群 《中国免疫学杂志》 北大核心 2025年第2期315-319,共5页
目的:探讨巨噬细胞极化对血管平滑肌细胞PI3K/Akt/mTOR信号通路和炎症反应的影响。方法:佛波酯诱导THP-1细胞成为巨噬细胞,分别用LPS和IFN-γ、IL-4和IL-13处理48 h,更换不含血清的新鲜培养基培养24 h,取上清作为条件培养基。将血管平... 目的:探讨巨噬细胞极化对血管平滑肌细胞PI3K/Akt/mTOR信号通路和炎症反应的影响。方法:佛波酯诱导THP-1细胞成为巨噬细胞,分别用LPS和IFN-γ、IL-4和IL-13处理48 h,更换不含血清的新鲜培养基培养24 h,取上清作为条件培养基。将血管平滑肌细胞分成对照组、M0培养基组、M1培养基组和M2培养基组。CCK-8检测细胞增殖能力,流式细胞术检测细胞凋亡,ELISA检测细胞上清中炎症因子IL-1α、IL-6和TGF-β表达,RT-qPCR和Western blot检测血管平滑肌细胞中PI3K、Akt、mTOR mRNA和磷酸化蛋白表达。结果:与对照组相比,M0培养基组细胞增殖能力、细胞上清中TGF-β水平显著降低(P<0.01),细胞凋亡率、细胞上清中IL-1α和IL-6水平、细胞中PI3K、Akt、mTOR mRNA和蛋白磷酸化水平显著升高(P<0.01);与M0培养基组相比,M1培养基组细胞增殖能力、细胞上清中TGF-β水平显著降低(P<0.05),细胞凋亡率、细胞上清中IL-1α和IL-6水平、细胞中PI3K、Akt、mTOR mRNA和蛋白磷酸化水平显著升高(P<0.01),M2培养基组趋势相反(P<0.05)。结论:巨噬细胞极化能够通过调控PI3K/Akt/mTOR信号通路调节炎症细胞因子表达,参与动脉粥样硬化炎症反应。 展开更多
关键词 巨噬细胞极化 动脉粥样硬化 PI3K/Akt/mTOR信号通路
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应用咽鼓管功能声测法和阶跃式纯音线谱信号对健康成人咽鼓管开放功能的研究 被引量:1
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作者 金蕾 郑阳阳 +1 位作者 倪坤 李晓艳 《听力学及言语疾病杂志》 北大核心 2025年第2期145-149,共5页
目的探究咽鼓管功能声测法合理的纯音声源信号频率区间,并初步建立正常值范围。方法选取31例健康成人受试者,分段采用3~6 kHz频带上间隔100 Hz的阶跃式纯音线谱信号作为声源进行咽鼓管功能声测法测试,分析结果。结果本研究发现3.5、4.3... 目的探究咽鼓管功能声测法合理的纯音声源信号频率区间,并初步建立正常值范围。方法选取31例健康成人受试者,分段采用3~6 kHz频带上间隔100 Hz的阶跃式纯音线谱信号作为声源进行咽鼓管功能声测法测试,分析结果。结果本研究发现3.5、4.3、4.35、4.5、4.65、4.8、5.0、5.15 kHz 8个频点通过率均较高,是较为合适的纯音信号频点;将这8个频率点上的线谱数据汇总后统计分析,计算出LVc值的95%可信区间,即95%的LVc值>5.5 dB,取整数后将6 dB设为LVc门限阈值。结论本研究发现咽鼓管功能声测法较合适的纯音线谱声源频率为3.5、4.3、4.35、4.5、4.65、4.8、5.0、5.15 kHz 8个频点,声源信号在吞咽动作发生前后约0.5~1秒范围内相对声压级超过6 dB幅值变化可作为咽鼓管有效开放指标。 展开更多
关键词 咽鼓管功能 纯音信号 声测法
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径向电流作用下的高压电缆缓冲层烧蚀多物理量信号演变规律 被引量:2
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作者 吴明 洪涵韬 +3 位作者 任志刚 张云飞 李建英 高景晖 《高电压技术》 北大核心 2025年第2期936-945,共10页
近年来高压电缆中缓冲层烧蚀导致的电缆本体击穿事故频发,严重影响了电网的安全稳定运行。缓冲层的含水率及外界压力是影响高压电缆缓冲层烧蚀故障发展的重要因素。基于此,搭建了缓冲层在不同含水率及不同受力下的烧蚀模拟试验平台,研... 近年来高压电缆中缓冲层烧蚀导致的电缆本体击穿事故频发,严重影响了电网的安全稳定运行。缓冲层的含水率及外界压力是影响高压电缆缓冲层烧蚀故障发展的重要因素。基于此,搭建了缓冲层在不同含水率及不同受力下的烧蚀模拟试验平台,研究不同条件下缓冲层烧蚀产生的温度、超声以及电信号,获得了烧蚀缺陷的多物理量演变规律。同时结合对烧蚀缓冲层的微观形貌特征以及烧蚀产物成分的表征,分析了不同条件下的缓冲层烧蚀信号产生的机理,发现电流径向集中引起的热效应和缓冲层内气隙放电是导致缓冲层温度升高的原因,而气隙放电是导致超声信号和电信号产生的原因。研究发现,相较干燥缓冲层烧蚀,含水情况下的缓冲层会和铝护套发生电化学腐蚀,会使得超声信号和电信号变大,且中间会有小的信号产生。该研究为高压电缆缓冲层烧蚀检测装置的开发提供了理论和实验基础。 展开更多
关键词 电力电缆 缓冲层 烧蚀故障 超声信号 径向电流
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基于改进变分模式分解的煤矿通风机振动信号特征提取 被引量:1
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作者 陶珑 郭燕飞 《工矿自动化》 北大核心 2025年第2期131-137,共7页
煤矿通风机振动信号是一种非平稳多分量信号。传统的非平稳信号特征信号提取方法存在自适应性差、对通风机早期故障的微弱特征辨识能力有限等问题,基于广义变分模式分解的特征提取方法的信号处理速度难以满足通风机振动信号特征快速提... 煤矿通风机振动信号是一种非平稳多分量信号。传统的非平稳信号特征信号提取方法存在自适应性差、对通风机早期故障的微弱特征辨识能力有限等问题,基于广义变分模式分解的特征提取方法的信号处理速度难以满足通风机振动信号特征快速提取的要求。针对上述问题,提出了一种基于改进变分模式分解的煤矿通风机振动信号特征快速提取方法。在广义变分模式分解算法的基础上,采用乘子交替方向法迭代求解,将约束优化问题转换为无约束优化问题。应用改进变分模式分解算法对信号进行等效分解,得到匹配目标信号特征的等效滤波器,通过内积变换原理快速提取通风机振动信号特征分量。仿真和实验结果表明,改进变分模式分解算法对不同强度的特征分量提取效果均较好,准确性和抗噪性良好,处理通风机实测振动信号的耗时为0.008165 s,与广义变分模式分解算法相比,特征提取速度大幅提升。 展开更多
关键词 煤矿通风机 振动信号 非平稳信号特征提取 变分模式分解 等效滤波器 内积变换
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基于改进YOLOv5s干扰跳频信号调制识别
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作者 张海宾 魏洪基 +3 位作者 王超 向长波 杨明洋 李晓龙 《郑州大学学报(工学版)》 北大核心 2025年第5期43-50,共8页
复杂电磁环境中干扰信号会严重恶化跳频信号检测和识别性能,为了解决传统的检测方法在实际应用中存在错检、漏检、误检、多检等问题,通过对YOLOv5s网络进行改进,提出一种基于时频图的信号检测和识别算法。首先,构建了跳频信号+干扰信号... 复杂电磁环境中干扰信号会严重恶化跳频信号检测和识别性能,为了解决传统的检测方法在实际应用中存在错检、漏检、误检、多检等问题,通过对YOLOv5s网络进行改进,提出一种基于时频图的信号检测和识别算法。首先,构建了跳频信号+干扰信号组合模式的数据集,包含4种不同跳频信号调制类型和6种不同干扰类型,每个组合生成300个高分辨率时频图样本,总计构建7200组数据;其次,考虑到干扰和信号在时频图上拥有相似的特征,而跳频信号频率会随时间不断跳变,这使得信号附近的背景信息成为区分信号与干扰的关键特征,提出利用语境分层模块对背景信息进行分级,采用深度可分离卷积模块提取信号附近的背景信息,利用门控聚合机制加权聚合背景信息和信号特征,输出更具判别力的复合特征;最后,利用语境分层模块与门控聚合机制对YOLOv5s网络的主干网络部分进行改造,得到改进的跳频信号检测器。仿真结果表明:较传统YOLOv5s网络,所提算法的召回率R提升15.9百分点,均值平均精度mAP@0.5∶0.95提升8.9百分点,F 1提升9百分点,错检、漏检等情况显著减少。 展开更多
关键词 跳频信号 信号检测 信号识别 干扰信号 YOLOv5s
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