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Graph Regularized L_p Smooth Non-negative Matrix Factorization for Data Representation 被引量:10
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作者 Chengcai Leng Hai Zhang +2 位作者 Guorong Cai Irene Cheng Anup Basu 《IEEE/CAA Journal of Automatica Sinica》 EI CSCD 2019年第2期584-595,共12页
This paper proposes a Graph regularized Lpsmooth non-negative matrix factorization(GSNMF) method by incorporating graph regularization and L_p smoothing constraint, which considers the intrinsic geometric information ... This paper proposes a Graph regularized Lpsmooth non-negative matrix factorization(GSNMF) method by incorporating graph regularization and L_p smoothing constraint, which considers the intrinsic geometric information of a data set and produces smooth and stable solutions. The main contributions are as follows: first, graph regularization is added into NMF to discover the hidden semantics and simultaneously respect the intrinsic geometric structure information of a data set. Second,the Lpsmoothing constraint is incorporated into NMF to combine the merits of isotropic(L_2-norm) and anisotropic(L_1-norm)diffusion smoothing, and produces a smooth and more accurate solution to the optimization problem. Finally, the update rules and proof of convergence of GSNMF are given. Experiments on several data sets show that the proposed method outperforms related state-of-the-art methods. 展开更多
关键词 Data clustering dimensionality reduction GRAPH REGULARIZATION LP smooth non-negative matrix factorization(SNMF)
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Homocysteine-induced Enhanced Expression of Tissue Factor in Human Vascular Smooth Muscle Cells 被引量:5
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作者 刘芳 黄瑞滨 +4 位作者 姚军霞 魏文宁 胡豫 宋善俊 李军 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2008年第5期520-524,共5页
The homocysteine (Hcy)-induced tissue factor (TF) expression in human vascular smooth muscle cells (VSMCs) and the effect of Hcy on the activity of nuclear factor-kappaB (NF-кB) and the expression of inducibl... The homocysteine (Hcy)-induced tissue factor (TF) expression in human vascular smooth muscle cells (VSMCs) and the effect of Hcy on the activity of nuclear factor-kappaB (NF-кB) and the expression of inducible nitric oxide synthase (iNOS) were investigated. Human umbilical artery VSMCs were cultured by tissue explanting method, identified by α-actin immunohistochemistry, and incubated with different concentrations of Hcy/PTDC (NF-кB inhibitor). Semi-quantitative RT-PCR was performed to detect the expression of TF mRNA in VSMCs. Flow cytometry was used to assay the expression of TF protein on the surface of VSMCs and the expression of iNOS in VSMCs. Western blot was carried out to detect the expression of NF-кB protein in nuclei. The results showed that Hcy could induce VSMCs expressing TF mRNA significantly after the VSMCs were incubated with Hcy at concentrations of 10, 100, 500 μmol/L respectively. There was low expression level of TF protein on the surface of the resting VSMCs and Hcy could also induce VSMCs expressing TF pro- tein on the cell surface in different concentrations. Additionally, Hcy could rapidly induce the activation of NF-кB and this effect could be significantly inhibited by PDTC. Hcy alone could not induce the expression of iNOS in VSMCs. It was concluded that Hcy could significantly induce the expression of TF in VSMCs and enhance the activation of NF-ΚB, subsequently mediate TF gene expression and protein synthesis. NF-кB-mediated expression of TF in VSMCs might be the important mechanism of atherosclerosis and thrombosis induced by Hcy. 展开更多
关键词 HOMOCYSTEINE vascular smooth muscle cell tissue factor nuclear factor kappaB inducible nitric oxide synthase
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Construction of human eukaryotic expression plasmid vascular endothelial growth factor 165 and its expression in transfected vascular smooth muscles 被引量:5
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作者 Zhong-Jun Wu, Xiao-Hong Yang, Shu-Sen Zheng, Su-Fen Yang and De Shi Organ Transplant Center, First Affiliated Hospital,Zhejiang University School of Medicine, Hangzhou 310003, China Department of General Surgery, Affiliated Hospital of ZunyiMedical College, Zunyi 563003 , China and Department ofVascular Surgery, Chongqing Medical University, Chongqing 400016 , Chi-na 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2004年第3期355-359,共5页
BACKGROUND: The highly specific vascular endothelialgrowth factor (VEGF) induces the growth of vascular en-dothelial cell. This study was to construct the eukaryoticexpression plasmid of vascular endothelial growth fa... BACKGROUND: The highly specific vascular endothelialgrowth factor (VEGF) induces the growth of vascular en-dothelial cell. This study was to construct the eukaryoticexpression plasmid of vascular endothelial growth factorl65(VEGF165) and observe its expression in vascular smoothmuscles (VSMCs).METHODS: The primers were designed and synthesizedaccording to the gene sequences of human VEGF165. TheVEGF165 gene was obtained from umbilic artery tissue bythe method of RT-PCR, then it was cloned to eukaryoticexpression plasmid pBudCE4.1 by recombination strategy.The eukaryotic expression plasmid named pBudCE4.1/VEGF165 was identified by restriction enzyme digestion,and was sequenced. The pBudCE4.1/VEGF165 was trans-fected into VSMCs by using lipofection. The VEGF165 ex-pression of mRNA and protein was detected by RT-PCRand Western blot respectively.RESULTS: VEGF165 was shown about 576bp by RT-PCR.Sequencing revealed the amplified VEGF165 gene was iden-tical with that in the GeneBank. Restrictive enzyme (HindBam HI) digestion analysis showed that recombinantexpression plasmid pBudCE4. l/tVEGF165 had been con-structed successfully. The expression of VEGF165 at mRNAand protein levels in the transformed VSMCs had beendemonstrated by RT-PCR and Western blot.CONCLUSIONS: The recombinant eukaryotic expressionplasmid pBudCE4.1/VEGF165 has been successfully con-structed and expressed in transformed VSMCs. The presentstudy has laid a foundation for VEGF165 gene therapy ofvascular stenosis in the transplant organ. 展开更多
关键词 eukaryotic expression plasmid human vascular endothelial growth factor vascular smooth muscle cell gene transfer organ transplant
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Transforming growth factor-β and smooth muscle differentiation 被引量:2
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作者 Xia Guo Shi-You Chen 《World Journal of Biological Chemistry》 CAS 2012年第3期41-52,共12页
Transforming growth factor(TGF)-β family members are multifunctional cytokines regulating diverse cel- lular functions such as growth,adhesion,migration, apoptosis,and differentiation.TGF-βs elicit their effects via... Transforming growth factor(TGF)-β family members are multifunctional cytokines regulating diverse cel- lular functions such as growth,adhesion,migration, apoptosis,and differentiation.TGF-βs elicit their effects via specific typeⅠand typeⅡserine/threonine kinase receptors and intracellular Smad transcription factors. Knockout mouse models for the different components of the TGF-β signaling pathway have revealed their critical roles in smooth muscle cell(SMC)differentia- tion.Genetic studies in humans have linked mutations in these signaling components to specific cardiovascular disorders such as aorta aneurysm and congenital heart diseases due to SMC defects.In this review,the current understanding of TGF-β function in SMC differentiation is highlighted,and the role of TGF-βsignaling in SMC- related diseases is discussed. 展开更多
关键词 TRANSFORMING growth factor β SMAD smooth MUSCLE cell Differentiation CARDIOVASCULAR DISEASES
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Qibai Pingfei capsule medicated serum inhibits the proliferation of hypoxia-induced pulmonary arterial smooth muscle cells via the Ca^(2+)/calcineurin/nuclear factor of activated T-cells 3 pathway 被引量:2
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作者 Zhu Jie Wang Baoqin +2 位作者 Liu Changan Tong Xiangli Li Zegeng 《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 2017年第4期466-474,共9页
OBJECTIVE: To observe the effect of Qibai Pingfei capsule(QBPF) medicated serum on the proliferation of rat pulmonary arterial smooth muscle cells(PASMCs) under hypoxia conditions and to investigate its key molecular ... OBJECTIVE: To observe the effect of Qibai Pingfei capsule(QBPF) medicated serum on the proliferation of rat pulmonary arterial smooth muscle cells(PASMCs) under hypoxia conditions and to investigate its key molecular effects on the Ca^(2+)/calcineurin/nuclear factor of activated T-cells 3(NFATc3) signaling pathway.METHODS: QBPF was provided to rats via continuous gavage for 10 days. Primary rat PASMCs were cultured using the direct adherent culture method.Methyl thiazolyl tetrazolium assay was used to eval-uate the effect of QBPF on PASMCs proliferation under hypoxia conditions. Laser scanning confocal microscopy was used to detect changes in intracellular free calcium([Ca^(2+)]_i) in PASMC-loaded Fluo-3-AM.Real-time quantitative polymerase chain reaction and western blot were used to detect the transcription and protein expression levels of calcineurin and NFATc3 genes in PASMCs.RESULTS: Compared with normoxia conditions,PASMCs proliferated at 12, 24, 48, and 72 h under hypoxia conditions. QBPF at concentrations of 5%,10%, and 20% could inhibit hypoxia-induced PASMC proliferation to different degrees. The inhibitory effect was most significant in the 20% QBPF group under 24 h hypoxia conditions. The concentration of [Ca^(2+)]_iin PASMCs under hypoxia was increased and [Ca^(2+)]_iwas significantly decreased when co-incubated with QBPF at 5%, 10%, and 20%. Compared with normoxia conditions, the m RNA and protein expression levels of calcineurin and NFATc3 in PASMCs induced by hypoxia were up-regulated.QBPF application significantly down-regulated m RNA and protein expression levels of calcineurin and NFATc3 in PASMCs.CONCLUSION: QBPF can effectively inhibit hypoxia-induced proliferation of PASMCs through down-regulation of key molecular expression via the Ca^(2+)/calcineurin/NFATc3 pathway. 展开更多
关键词 Hypertension pulmonary Myocytes smooth muscle Vascular remodeling NFATC transcription factors
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Partial Purification of Smooth Muscle Cell Derived Growth Factor
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作者 杨仕林 邓仲端 瞿智玲 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 1996年第2期78-82,共5页
The serum free medium conditioned by cultured rabbit aortic smooth muscle cells was partially purified using ultrafiltration and heparin affinity chromatography. Incorporation of [ ̄3H]-thymidine ( ̄3H-TdR) into cell ... The serum free medium conditioned by cultured rabbit aortic smooth muscle cells was partially purified using ultrafiltration and heparin affinity chromatography. Incorporation of [ ̄3H]-thymidine ( ̄3H-TdR) into cell DNA was used to measure the mitogenic activity of the fractions from chromatography for NIH 3T3 fibroblasts. The molecular weight and the iso-electric point of these fractions were determined by NaDodSO_4-polyacrylamide gel electrophoresis (SDS-PAGE)and iso-electric focusing, respectively. The results showed that the protein eluted in 1.0-1. 6 mol/L NaCl from the heparin-Sepharose was mitogenic for 3T3 cells,and this protein had a molecular weight of 22. 8-26. 7 ku and an iso-electric point of about 4. 6. The fact that the above-mentioned biochemical properties differed from that of PDGF, IGF and FGF suggests that this mitogenic protein may be a separate growth factor. 展开更多
关键词 growth factor smooth muscle cell PURIFICATION ATHEROSCLEROSIS
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Different distributions of interstitial cells of Cajal and platelet-derived growth factor receptor-α positive cells in colonic smooth muscle cell/interstitial cell of Cajal/plateletderived growth factor receptor-α positive cell syncytium in mice 被引量:9
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作者 Chen Lu Xu Huang +5 位作者 Hong-Li Lu Shao-Hua Liu Jing-Yu Zang Yu-Jia Li Jie Chen Wen-Xie Xu 《World Journal of Gastroenterology》 SCIE CAS 2018年第44期4989-5004,共16页
AIM To investigate the distribution and function of interstitialcells of Cajal(ICCs) and platelet-derived growth factor receptor-α positive(PDGFRα+) cells in the proximal and distal colon.METHODS The comparison of c... AIM To investigate the distribution and function of interstitialcells of Cajal(ICCs) and platelet-derived growth factor receptor-α positive(PDGFRα+) cells in the proximal and distal colon.METHODS The comparison of colonic transit in the proximal and distal ends was performed by colonic migrating motor complexes(CMMCs). The tension of the colonic smooth muscle was examined by smooth muscle spontaneous contractile experiments with both ends of the smooth muscle strip tied with a silk thread. Intracellular recordings were used to assess electrical field stimulation(EFS)-induced inhibitory junction potentials(IJP) on the colonic smooth muscle. Western blot analysis was used to examine the expression levels of ICCs and PDGFRα in the colonic smooth muscle.RESULTS Treatment with NG-nitro-L-arginine methyl ester hydrochloride(L-NAME) significantly increased the CMMC frequency and spontaneous contractions, especially in the proximal colon, while treatment with MRS2500 increased only distal CMMC activity and smooth muscle contractions. Both CMMCs and spontaneous contractions were markedly inhibited by NPPB, especially in the proximal colon. Accordingly, CyPPA sharply inhibited the distal contraction of both CMMCs and spontaneous contractions. Additionally, the amplitude of stimulationinduced nitric oxide(NO)/ICC-dependent slow IJPs(sIJPs) by intracellular recordings from the smooth muscles in the proximal colon was larger than that in the distal colon, while the amplitude of electric field stimulationinduced purinergic/PDGFRα-dependent fast IJPs(fIJPs) in the distal colon was larger than that in the proximal colon. Consistently, protein expression levels of c-Kit and anoctamin-1(ANO1) in the proximal colon were much higher, while protein expression levels of PDGFRα and small conductance calcium-activated potassium channel 3(SK3) in the distal colon were much higher.CONCLUSION The ICCs are mainly distributed in the proximal colon and there are more PDGFRα+ cells are in the distal colon, which generates a pressure gradient between the two ends of the colon to propel the feces to the anus. 展开更多
关键词 Interstitial cells of Cajal Platelet-derived growth factor receptor-α positive cells smooth muscle cell/interstitial cell of Cajal/platelet-derived growth factor receptor-α positive cell syncytium Nitric oxide PURINE
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Effect of Nuclear Factor-kappa B on Vascular Endothelial Growth Factor mRNA Expression of Human Pulmonary Artery Smooth Muscle Cells in Hypoxia
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作者 张焕萍 徐永健 +3 位作者 张珍祥 许淑云 倪望 陈士新 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2004年第1期9-12,18,共5页
In order to investigate the effect of nuclear factor kappa B (NF κB) on vascular endothelial growth factor (VEGF) mRNA expression of human pulmonary artery smooth muscle cells (HPASMCs) in hypoxia, the cultured HPA... In order to investigate the effect of nuclear factor kappa B (NF κB) on vascular endothelial growth factor (VEGF) mRNA expression of human pulmonary artery smooth muscle cells (HPASMCs) in hypoxia, the cultured HPASMCs in vitro were stimulated with pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF κB. The NF κB p65 nuclei positive expression was detected by immunocytochemical technique. The IκBα protein expression was measured by Western blot. RT PCR was used to detect the VEGF mRNA expression of HPASMCs. The results showed that no significant change was observed in the NF κB p65 nuclei positive expression of cultured HPASMCs during 6 h-24 h in normoxia, but the levels of NF κB p65 nuclei positive expression of cultured HPASMCs were significantly increased in hypoxia groups as compared with those in all normoxia groups ( P <0.05). The IκBα protein expression of cultured HPASMCs showed no significant change during 6 h-24 h in normoxia, but significantly decreased in hypoxia as comapred with that in normoxia groups ( P <0.05). PDTC (1 to 100 μmol/L) could inhibit the VEGF mRNA expression of HPASMCs in a concentration dependent manner in hypoxia. In conclusion, NF κB can be partly translocation activated from cytoplasm into nuclei in the cultured HPASMCs under hypoxia. The inhibition of NF κB activation can decrease the VEGF mRNA expression. It is suggested that the activation of NF κB is involved in the VEGF mRNA expression of HPASMCs under hypoxia. 展开更多
关键词 HYPOXIA pulmonary artery smooth muscle vascular endothelial growth factor nuclear factor kappa B
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Up and Down Expression of Androgen Receptor, Estrogen Receptor beta and Platelet Derived Growth Factor beta by Testosterone in Aortic Vascular Smooth Muscle Tissues
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作者 吴赛珠 吕红松 +5 位作者 周可祥 孙飞 马瑞 郑华 隗和明 容志毅 《South China Journal of Cardiology》 CAS 2004年第2期116-122,共7页
Objectives To investigate the effects of testosterone enanthate (TE) on serum lip- ids and lipoproteins metabolism and the expression of androgen receptor (AR) , estrogen receptor beta ( ER - β) and platelet derived ... Objectives To investigate the effects of testosterone enanthate (TE) on serum lip- ids and lipoproteins metabolism and the expression of androgen receptor (AR) , estrogen receptor beta ( ER - β) and platelet derived growth factor beta ( PDGFR - β) in aortic vascular smooth muscle tissues (VSMTs). Methods Forty aged male rats were ran- domly divided into 4 groups, group A (placebo group) , group B (2. 5 mg/kg intramuscular injection of TE once a week ) , group C (5.0 mg/kg intramuscular injection of TE once a week ) , group D ( 10. 0 mg/kg intramus- cular injection of TE once a week). All animals were fed freely during 16 - week treatment periods. The ex- pression of AR ,ER - βand PDGFR - β were studied by Western bolt. Results Average serum LDL - C was lower in group D than that in group A ( p < 0. 01 ). Compared with the other groups, average serum TC was also lower in group D (p <0. 05). AR expression in aortic vascular smooth muscle tissues could be regulated by TE: 99.50 ±21.74, 125.38 ±28.68 and 101.98 ± 15.42 for TE concentrations at 2.5 mg/kg, 5.0 mg/kg and 10.0 mg/kg, respectively , the expression of ER - β could be regulated by TE: 92. 34 ± 18. 68, 47. 72 ± 18.12, 82.13 ±23.50, and the expression of PDGFR - β could be regulated as well by TE: 219.70 ±45. 59, 50.16 ±9. 72, 125.36 ±15. 74(Data for AR ,ER-β and PDGFR - β protein band intensity were expressed with x ± s, with control group taken as 100 ).Conclusions This study indicates that androgens have significant effects on serum lipids and lipoprotein metabolism. Testosterone enanthate at 5. 0 mg/kg can stimulate the expression of AR, but inhibite the expres- sion of PDGFR. Testosterone enanthate at the concen- trations of 5. 0 mg/kg and 10. 0 mg/kg can inhibite the expression of ER - β. 展开更多
关键词 androgen receptor platelet de- rived growth factor estrogen coronary heart dis- ease aortic vascular smooth muscle testosterone
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Interleukin-1β,Tumor Necrosis Factor-α and Lipopolysaccharide Induce Expression of Monocyte Chemoattractant Protein-1 in Calf Aortic Smooth Muscle Cells 被引量:2
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作者 孟峰 邓仲端 倪娟 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2000年第1期36-38,共3页
Summary: To investigate whether interleukin-1β(IL-1β), tumor necrosis factor-α (TNF-α) and lipopolysaccharide (LPS) induce expression of monocyte chemoattractant protein-1 (MCP-1 ) mRNA and protein in calf aortic ... Summary: To investigate whether interleukin-1β(IL-1β), tumor necrosis factor-α (TNF-α) and lipopolysaccharide (LPS) induce expression of monocyte chemoattractant protein-1 (MCP-1 ) mRNA and protein in calf aortic smooth muscle cells(SMCs), calf aortic SMCs were cultured by a substrate-attached explant method. The cultured SMCs were used between the third to the fifth passage. After the cells became confluent, the SMCs were exposed to 2 ng/ml IL-1β, 20ng/ml TNF-1α and 100 ng/ml LPS respectively, and the total RNA of SMCs which were incubated for 4 h at 37℃ were extracted from the cells by using guanidinium isothiocyanate method. The expres- ion of MCP-1 mRNA in SMCs was detected by using dot blotting analysis using a probe of γ-32 P- end-labelled 35-mer oligonucleotide. After a 24-h incubation, the media conditioned by the cul- tured SMCs were collected. The MCP-1 protein content in the conditioned media was determined by using sandwich ELISA. The results were as follows: Dot blotting analysis showed that the cul- tured SMCs could express MCP-1 mRNA. After a 4-h exposure to IL-1β, TNF-α and LPS, the MCP-1 mRNA expression in SMCs was increased (3.6-fold, 2. 3-fold and 1. 6-fold, respectively). ELISA showed that the levels of MCP-1 protein in the conditioned media were also increased (2.9- fold, 1.7-fold and 1.1-fold, respectively). The results suggest that calf aortic SMCs could ex- press MCP-1 mRNA and protein. IL-1β and TNF-α can induce strong expression of MCP-1 mRNA and protein, and the former is more effective than the latter. 展开更多
关键词 INTERLEUKIN-1Β tumor necrosis factor α lipopolysaccaride monocyte chemoattractant protein 1 muscle smooth vascular
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综采工作面对讲系统非平稳噪声低功耗去噪方法
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作者 杨艺 谭晓 +3 位作者 常亚军 王科平 刘斌斌 王田 《煤炭学报》 北大核心 2025年第7期3692-3706,共15页
综采工作面语音对讲系统面临严重的非平稳噪声干扰。在功耗限制条件下,实现对讲系统的超低信噪比语音去噪,是确保工作面语音信息正确传输的核心技术之一。基于IMCRA算法,提出一种面向综采工作面语音特点的非平稳噪声去除方法 MIMCRA。其... 综采工作面语音对讲系统面临严重的非平稳噪声干扰。在功耗限制条件下,实现对讲系统的超低信噪比语音去噪,是确保工作面语音信息正确传输的核心技术之一。基于IMCRA算法,提出一种面向综采工作面语音特点的非平稳噪声去除方法 MIMCRA。其中,针对先验信噪比估计延迟导致的非平稳噪声估计不准的问题,引入改进2步噪声去除方法。即利用前一帧的先验信噪比和当前帧的纯净语音来滚动估计当前帧的先验信噪比和下一帧的纯净语音,实现了先验信噪比实时估计。针对固定平滑因子对含噪功率谱进行平滑处理容易引起噪声过估计,从而导致语音信息难以提取的问题,引入帧-频动态平滑因子调节机制。以平滑功率谱密度和噪声功率谱密度的最小均方差为依据,对含噪语音的功率谱实现动态平滑处理。针对信噪比过低,噪声去除不彻底的问题,提出一种面向弱语音分量保护的噪声存在概率检测机制。根据2~4 kHz频率范围内,噪声与弱语音能量分布的统计特性差别,对去噪后的信号再进行噪声检测,并消除存在的残余噪声。对比试验结果表明:当输入语音信噪比为-5~10 dB时,MIMCRA算法与IMCRA算法相比,分段信噪比提高约3 dB,分段误差降低约0.3,对数谱距离降低约0.2。特别当语音信噪比为-5 dB时,MIMCRA算法仍然能将分段信噪比提高到-2.799 5 dB,表明该算法对超低信噪比含噪语音有较强的去噪能力。MIMCRA算法在郑煤机最新研发的综采工作面对讲系统中实现了低功耗部署,芯片功耗为16.5~66.0 mW;处理32 ms帧长的语音帧耗时约16 ms,达到实时性要求。 展开更多
关键词 单通道语音降噪 非平稳噪声 语音活动检测 先验信噪比 帧-频动态平滑因子
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蒙特卡罗MagicMC程序网格权窗全局减方差模块开发与验证
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作者 曲泓宇 陈珍平 +6 位作者 孙爱扣 雷济充 刘程伟 朱琳 张羿 张怡卿 于涛 《核电子学与探测技术》 北大核心 2025年第4期481-489,共9页
在大尺度辐射屏蔽计算中,蒙特卡罗(Monte Carlo,MC)方法面临粒子深穿透现象,导致计算精度低、统计误差大、收敛速度慢等问题。为满足计算精度和效率的要求,通常采用网格权窗减方差方法缓解粒子输运深穿透问题。针对上述问题,本文基于蒙... 在大尺度辐射屏蔽计算中,蒙特卡罗(Monte Carlo,MC)方法面临粒子深穿透现象,导致计算精度低、统计误差大、收敛速度慢等问题。为满足计算精度和效率的要求,通常采用网格权窗减方差方法缓解粒子输运深穿透问题。针对上述问题,本文基于蒙特卡罗程序MagicMC开发了网格权窗全局减方差模块,建立了基于MC-MC正向耦合的自适应平滑因子改进网格权窗方法。通过对ITER基准题计算,结果表明在相同条件下,不同位置的通量值与参考解对比,数值吻合,并且FOM因子提高了约7倍。同时,针对1/4 NUREG/CR-6115PWR基准题开展了网格中子通量密度分布计算,与直接模拟相比,本文全局减方差方法的FOM因子提高了9倍左右。数值分析结果验证了本文开发的网格权窗全局减方差模块的正确性与可靠性,提升了MagicMC程序对大尺度辐射屏蔽问题的计算分析能力。 展开更多
关键词 辐射屏蔽 蒙特卡罗 网格权窗 减方差 平滑因子
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活化T淋巴细胞核因子5在高盐诱导小鼠平滑肌细胞衰老中的作用及其机制
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作者 仲威 戴芝银 +2 位作者 崔星钢 李波 姜瑜 《吉林大学学报(医学版)》 北大核心 2025年第3期567-575,共9页
目的:探讨活化T淋巴细胞核因子5 (NFAT5)抑制剂KRN5在高盐诱导小鼠血管平滑肌细胞(VSMCs)衰老中的作用,并阐明其作用机制。方法:30只8周龄雄性ApoE-/-小鼠分为正常组、衰老组和高盐处理衰老组,每组10只,衰老组和高盐处理衰老组构建小鼠... 目的:探讨活化T淋巴细胞核因子5 (NFAT5)抑制剂KRN5在高盐诱导小鼠血管平滑肌细胞(VSMCs)衰老中的作用,并阐明其作用机制。方法:30只8周龄雄性ApoE-/-小鼠分为正常组、衰老组和高盐处理衰老组,每组10只,衰老组和高盐处理衰老组构建小鼠自然衰老模型;分离培养小鼠VSMCs,将VSMCs分为正常组、衰老组、高盐处理衰老组和高盐处理衰老+KRN5组。采用β-半乳糖苷酶(Sa-β-gal)染色法检测各组小鼠主动脉组织和VSMCs衰老情况,免疫荧光法检测各组小鼠主动脉组织和VSMCs中NFAT5和磷酸化的组蛋白H2A变异体X (γ-H2AX)蛋白表达情况,实时荧光定量PCR (RT-qPCR)法检测各组细胞中NFAT5、 γ-H2AX、细胞周期依赖性激酶抑制剂2A(P16)和细胞周期依赖性激酶抑制剂1A (P21) mRNA表达水平,Western blotting法检测各组VSMCs中NFAT5、γ-H2AX、P16和P21蛋白表达水平。结果:Sa-β-gal染色法,与正常组比较,衰老组和高盐处理衰老组小鼠主动脉组织衰老阳性面积比例均明显增加(P<0.05),小鼠VSMCs衰老细胞阳性比例均明显增加(P<0.05)。与衰老组比较,高盐处理衰老组小鼠VSMCs衰老细胞阳性比例明显增加(P<0.05);与高盐处理衰老组比较,高盐处理衰老+KRN5组小鼠VSMCs衰老细胞阳性比例明显减少(P<0.01)。免疫荧光法,与正常组比较,衰老组小鼠VSMCs中γ-H2AX蛋白表达量明显增加(P<0.05);与衰老组比较,高盐处理衰老组小鼠主动脉组织中SA-β-gal染色和NFAT5蛋白表达量均明显增加(P<0.05);与正常组比较,衰老组和高盐处理衰老组小鼠VSMCs中NFAT5蛋白表达量明显增加(P<0.05);与衰老组比较,高盐处理衰老组小鼠VSMCs中NFAT5蛋白表达量明显增加(P<0.05)。RT-qPCR法,与正常组比较,衰老组和高盐处理衰老组小鼠VSMCs中NFAT5、γ-H2AX、P16及P21 mRNA表达水平均明显升高(P<0.05);与衰老组比较,高盐处理衰老组小鼠VSMCs中NFAT5、γ-H2AX、P16和P21 mRNA表达水平均明显升高(P<0.05);与衰老组比较,高盐处理衰老组和高盐处理衰老+KRN5组小鼠VSMCs中NFAT5、γ-H2AX、P16及P21mRNA表达水平均明显升高(P<0.05);与高盐处理衰老组比较,高盐处理衰老+KRN5组小鼠VSMCs中NFAT5、γ-H2AX、P16和P21 mRNA表达水平均明显降低(P<0.05)。Western blotting法,与正常组比较,衰老组和高盐处理衰老组小鼠VSMCs中NFAT5、γ-H2AX、P16及P21蛋白表达水平均明显升高(P<0.05);与衰老组比较,高盐处理衰老组小鼠VSMCs中NFAT5、γ-H2AX、P16和P21蛋白表达水平均明显升高(P<0.05);与衰老组比较,高盐处理衰老组和高盐处理衰老+KRN5组小鼠VSMCs中NFAT5、γ-H2AX、P16及P21蛋白表达水平均明显升高(P<0.05);与高盐处理衰老组比较,高盐处理衰老+KRN5组小鼠VSMCs中NFAT5、γ-H2AX、P16和P21蛋白表达水平均明显降低(P<0.05)。结论:NFAT5对高盐诱导小鼠VSMCs衰老可能具有一定促进作用。 展开更多
关键词 血管衰老 活化T淋巴细胞核因子5 KRN5 血管平滑肌细胞 Β-半乳糖苷酶
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基于自适应空谱约束的加权残差NMF高光谱图像解混
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作者 陈善学 戚俊杰 《信号处理》 北大核心 2025年第3期553-568,共16页
标准的非负矩阵分解(Nonnegative Matrix Factorization,NMF)模型应用于高光谱图像解混时,由于模型的非凸性、光谱和空间先验信息未充分利用的问题,导致解混精度不高。为提高解混性能,提出了一种基于自适应空谱约束的加权残差非负矩阵... 标准的非负矩阵分解(Nonnegative Matrix Factorization,NMF)模型应用于高光谱图像解混时,由于模型的非凸性、光谱和空间先验信息未充分利用的问题,导致解混精度不高。为提高解混性能,提出了一种基于自适应空谱约束的加权残差非负矩阵分解高光谱图像解混算法。该算法首先,对传统的NMF模型进行改进,利用在迭代过程中原始高光谱图像矩阵与重构图像矩阵之间的残差来构建残差权重因子,为损失函数的每一行分配贡献权重,以减轻噪声的影响,提高算法的鲁棒性。其次,为利用高光谱图像丰富的先验信息,算法引入像元空谱相似度来衡量像元间的相似性以捕获像元在空间及光谱上的联系,并由相似度矩阵自适应地确定像元邻域来构造空间权重因子,提升了丰度的分段平滑性。此外,结合丰度矩阵的固有特征,构造光谱权重因子,促进了丰度的稀疏性。最后,由于高光谱图像具有较高的光谱分辨率,相邻波段的反射值变化较小,因此端元光谱具有一定的平滑度,算法通过端元光谱反射值间的差异分配平滑权重,以调整在迭代过程中端元光谱的平滑程度。本文利用梯度下降推导出算法的乘法更新规则,为证明所提算法的有效性,将其与其他几种算法在模拟数据以及Jasper Ridge和Urban两个真实高光谱数据上进行实验,实验结果验证了该算法具有更好的解混性能。 展开更多
关键词 高光谱图像解混 非负矩阵分解 加权残差 像元空谱相似度 平滑权重
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三相变频器回路串联故障电弧检测方法研究
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作者 高洪鑫 王坤远 +1 位作者 王智勇 蔡佳成 《电子测量与仪器学报》 北大核心 2025年第1期203-215,共13页
串联故障电弧是引发电气火灾的主要因素之一,针对未知工况条件下串联故障电弧难以准确检测的问题,提出了一种基于实时训练更新核极限学习机(KELM)预测模型的串联故障电弧检测方法。首先,利用三相电动机和变频器负载开展了不同电源谐波... 串联故障电弧是引发电气火灾的主要因素之一,针对未知工况条件下串联故障电弧难以准确检测的问题,提出了一种基于实时训练更新核极限学习机(KELM)预测模型的串联故障电弧检测方法。首先,利用三相电动机和变频器负载开展了不同电源谐波、变频器载波频率、变频器运行频率和电流等级条件下的串联故障电弧实验;其次,利用奇异值分解滤波、改进一次指数平滑滤波依次对电流信号进行降噪处理;再次,利用前两个周波电流信号训练更新KELM预测模型,并计算预测模型对下一个周波电流信号的预测残差,然后利用预测残差绝对值构建矩阵,结合非负矩阵分解将残差矩阵降维成一维向量,并利用一维向量的最大值作为故障特征,结合固定阈值实现串联故障电弧检测;最后,测试了提出方法在未知工况条件下的串联故障电弧检测性能和抗噪性能。结果表明:提出方法可以有效检测出未知电源谐波、变频器载波频率、变频器运行频率和电流等级4类未知工况条件下的串联故障电弧,且具有较强的抗噪能力。 展开更多
关键词 串联故障电弧 核极限学习机 奇异值分解滤波 改进一次指数平滑滤波 预测残差 非负矩阵分解
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基于水位低通滤波的入库流量反推方法研究
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作者 王鹏翔 殷兆凯 +5 位作者 张子平 许红断 马安国 黄迪 翟然 梁犁丽 《水利水电技术(中英文)》 北大核心 2025年第5期134-143,共10页
【目的】准确的入库流量数据是水库调度运行及水文预报依赖的重要基础数据,但经由水量平衡法直接推求的入库流量过程通常呈锯齿震荡且存在大量异常负值,现有通用方法在平滑效果及适用性方面还有待进一步提升。【方法】从造成入库流量锯... 【目的】准确的入库流量数据是水库调度运行及水文预报依赖的重要基础数据,但经由水量平衡法直接推求的入库流量过程通常呈锯齿震荡且存在大量异常负值,现有通用方法在平滑效果及适用性方面还有待进一步提升。【方法】从造成入库流量锯齿震荡的直接原因入手,采用低通滤波方法,除去掺杂在水位数据中影响水位库容计算的高频噪声,减少其对入库流量推求的影响。【结果】结果显示:(1)对于整个流量过程,水位低通滤波方法计算所得入库流量数据中的负值占比仅为3.20%,负值均值仅为-29.76 m^(3)/s,平滑改善度为0.77,表现最佳,滑动平均法次之,五点三次法最差;(2)对于不同量级典型洪水过程,低通滤波方法在保证了较好平滑改善度的前提下减少了平滑处理对洪峰和峰现时间的影响。【结论】结果表明:基于水位低通滤波的入库流量反推方法计算原理简单,在保证了较好平滑改善度的前提下,大大减少了入库流量过程中的异常负值,同时对洪峰和峰现时间的影响较小,可以有效提升入库流量反推结果的合理性。 展开更多
关键词 入库流量 数据平滑 低通滤波 水库水位 影响因素
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基于改进GRNN的煤矿井下瓦斯浓度预测
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作者 张兆宏 刘伟 +1 位作者 单宇廷 王英伟 《能源与环保》 2025年第6期56-61,71,共7页
瓦斯含量反映煤层瓦斯储存,瓦斯浓度指空气中瓦斯占比,由于存在电磁干扰等多种因素,导致瓦斯浓度预测时面临相对误差和均方误差较高的问题,这种数据精度上的不足,影响了对煤矿井下瓦斯浓度的准确预测,使得预测效果较差。为此,提出基于改... 瓦斯含量反映煤层瓦斯储存,瓦斯浓度指空气中瓦斯占比,由于存在电磁干扰等多种因素,导致瓦斯浓度预测时面临相对误差和均方误差较高的问题,这种数据精度上的不足,影响了对煤矿井下瓦斯浓度的准确预测,使得预测效果较差。为此,提出基于改进GRNN的煤矿井下瓦斯浓度预测方法,该方法使用瓦斯传感器采集煤矿井下瓦斯含量数据,作为煤矿井下瓦斯浓度预测样本;构建基于改进GRNN的瓦斯浓度预测模型,由果蝇算法寻优设定可实现瓦斯浓度预测结果均方误差最小化的平滑因子,改进GRNN模型,利用此模型学习瓦斯含量与浓度之间关系,预测煤矿井下瓦斯浓度。实验结果显示,利用此方法预测瓦斯浓度时,全量程最大相对误差2.6%,最小均方误差为0.015,瓦斯浓度预测值与实际值基本一致,预测煤矿井下瓦斯浓度效果较好。 展开更多
关键词 改进GRNN 煤矿井下 瓦斯浓度预测 瓦斯传感器 果蝇算法 平滑因子
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Nrf2通过降低有氧糖酵解缓解CoCl_(2)诱导的大鼠肺动脉平滑肌细胞增殖和迁移
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作者 张穗 黄家瑜 +2 位作者 何丽丽 买热甫喀·木合塔尔 罗琴 《中国病理生理杂志》 北大核心 2025年第5期919-926,共8页
目的:探究核因子E2相关因子2(nuclear factor E2-related factor 2,Nrf2)通过有氧糖酵解途径影响CoCl_(2)诱导的低氧条件下原代大鼠肺动脉平滑肌细胞(pulmonary artery smooth muscle cells,PASMCs)的增殖和迁移,并揭示其潜在的作用机... 目的:探究核因子E2相关因子2(nuclear factor E2-related factor 2,Nrf2)通过有氧糖酵解途径影响CoCl_(2)诱导的低氧条件下原代大鼠肺动脉平滑肌细胞(pulmonary artery smooth muscle cells,PASMCs)的增殖和迁移,并揭示其潜在的作用机制。方法:采用酶消化法分离原代SD大鼠PASMCs,并通过200μmol/L CoCl_(2)诱导建立化学性低氧细胞模型。实验设置0、6、24和48 h四个时点观察CoCl_(2)刺激下PASMCs中有氧糖酵解关键酶[丙酮酸激酶M2型(pyruvate kinase M2,PKM2)、乳酸脱氢酶A(lactate dehydrogenase A,LDHA)和单羧酸转运体蛋白4(monocarboxylate transporter 4,MCT4)]及增殖细胞核抗原(proliferating cell nuclera antigen,PCNA)的蛋白表达变化。通过Western blot筛选Nrf2激活剂富马酸二甲酯(dimethyl fumarate,DMF)和抑制剂ML385的最佳作用浓度,随后将细胞分为4组:常氧对照(normoxic control,NC)组、CoCl_(2)组、CoCl_(2)+DMF组及NC+ML385组,分别检测各组PASMCs的增殖和迁移能力,以及HIF-1α、Nrf2和有氧糖酵解关键酶的蛋白表达水平。结果:在CoCl_(2)诱导大鼠PASMCs低氧细胞模型中,随着低氧时间的延长,Nrf2蛋白水平显著下降(P<0.05),有氧糖酵解关键酶及PCNA蛋白水平显著升高(P<0.05),PASMCs迁移能力显著增强(P<0.05)。DMF干预后有氧糖酵解关键酶的蛋白表达与大鼠PASMCs增殖和迁移能力显著下降(P<0.05),而ML385抑制Nrf2表达后以上实验结果均出现相反变化(P<0.05)。结论:Nrf2可以通过降低有氧糖酵解缓解CoCl_(2)诱导化学性低氧原代大鼠PASMCs的增殖和迁移。 展开更多
关键词 肺动脉平滑肌细胞 有氧糖酵解 核因子E2相关因子2 细胞增殖 细胞迁移
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人尿源性干细胞的分离培养及诱导分化为平滑肌细胞
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作者 陈佳汇 戴晓琪 +8 位作者 徐彦钢 李远超 黄妹 詹一飞 杜宇轩 李鎏强 郭耀川 卞军 赖德辉 《中国组织工程研究》 CAS 北大核心 2025年第19期4076-4082,共7页
背景:传统尿路修复重建手段受限于供体短缺、并发症多以及生理功能恢复不理想等问题,组织工程策略为此领域提供了新方向。鉴于尿路主要由肌性组织构成,其中关键在于发掘适合的种子细胞并高效诱导分化为平滑肌细胞,但关于不同平滑肌细胞... 背景:传统尿路修复重建手段受限于供体短缺、并发症多以及生理功能恢复不理想等问题,组织工程策略为此领域提供了新方向。鉴于尿路主要由肌性组织构成,其中关键在于发掘适合的种子细胞并高效诱导分化为平滑肌细胞,但关于不同平滑肌细胞诱导方案效能的对比研究仍较为匮乏。目的:旨在分离、培养及鉴定人尿源性干细胞,并比较两种不同成平滑肌诱导方案的效果。方法:采用多次离心法从11份健康成人志愿者尿液中分离提取尿源性干细胞,使用流式细胞仪进行表面标志物的鉴定,通过成骨、成脂诱导分化来验证尿源性干细胞的多向分化潜能。尿源性干细胞分别在含转化生长因子β1以及转化生长因子β1联合血小板衍生生长因子的成平滑肌细胞诱导分化培养基中诱导分化14 d,采用免疫荧光染色和Western blot检测平滑肌特异性蛋白(α-SMA、SM22)的表达差异。结果与结论:①成功从8份健康人尿液中分离出尿源性干细胞,细胞呈“米粒”样,具有很好的分裂增殖能力;②尿源性干细胞高表达间充质干细胞表面标志物CD73、CD90和CD44,极低表达造血干细胞表面标志物CD34和CD45,不表达CD19、CD105和HLA-DR;③经成骨和成脂诱导分化后,可见明显的钙结节和脂滴形成,茜素红染色和油红O染色结果呈阳性;④成平滑肌诱导培养14 d,免疫荧光染色显示转化生长因子β1/血小板衍生生长因子组尿源性干细胞成平滑肌诱导分化率显著高于转化生长因子β1组(P<0.005);⑤成平滑肌诱导培养14 d,Western blot检测显示转化生长因子β1/血小板衍生生长因子组α-SMA和SM22蛋白表达量显著高于转化生长因子β1组(P<0.005)。结果表明:尿源性干细胞可以通过多次离心法无创分离获取;相较于单纯转化生长因子β1,转化生长因子β1/血小板衍生生长因子联合应用能显著提高尿源性干细胞诱导分化为平滑肌细胞的效率。 展开更多
关键词 尿源性干细胞 诱导分化 平滑肌细胞 转化生长因子β1 血小板衍生生长因子 组织工程
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移动窗口多普勒平滑伪距增强的GNSS/IMU/单目视觉紧组合定位
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作者 何进辛 高井祥 +1 位作者 潘诚 王永辉 《测绘通报》 北大核心 2025年第1期101-106,共6页
本文针对在多源融合导航系统中GNSS伪距观测值受环境影响较大使得定位精度下降的问题,提出了基于移动窗口的多普勒平滑伪距算法。首先建立基于因子图优化的GNSS/IMU/单目视觉紧组合导航系统模型,然后使用开源数据集验证算法的有效性并... 本文针对在多源融合导航系统中GNSS伪距观测值受环境影响较大使得定位精度下降的问题,提出了基于移动窗口的多普勒平滑伪距算法。首先建立基于因子图优化的GNSS/IMU/单目视觉紧组合导航系统模型,然后使用开源数据集验证算法的有效性并与常规加权多普勒平滑伪距算法进行对比。结果表明,该算法在伪距定位中E、N和U 3个方向上定位精度分别达到1.591、2.892和2.001 m,定位精度分别提升了50.7%、61.7%、56.8%;在多源融合导航定位系统中定位精度分别达到1.390、2.561和1.606 m,比未平滑前的定位精度3个方向上分别提高了9.8%、20.0%和11.1%;同时该结果与常规加权多普勒平滑相比,定位精度分别提升了4.7%、3.1%、0.5%。 展开更多
关键词 多源融合导航 因子图 伪距 移动窗口 多普勒平滑
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