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Investigation on subsurface vortices within a closed pump intake under different pressure conditions

Journal of Hydrodynamics 2020年第5期32卷 914-928页

作者： Miao Guo Xue-lin Tang xiao-qin Li Fu-jun Wang xiao-yan shi College of Water Resources and Civil Engineering China Agricultural UniversityBeijing 100083China Beijing Engineering Research Centre of Safety and Energy Saving Technology for Water Supply Network System China Agricultural UniversityBeijing 100083China

An experimental study to investigate various features of subsurface vortices and their evolutions inside a closed pump intake under different pressure conditions at free surface,and to analyze the influence of a pipe bell with different mean axial velocities at the same water level on flow patterns is *** all cases,three different flow regimes are closely observed:various side-wall attached,back-wall attached and submerged vortices structures,and their evolutions are subject to the free-surface pressure for a critical flow rate,the number and strength of all these vortex rise as the absolute value of the pressure increases for a higher flow rate,for a lower flow rate,whether the side-wall vortices occur or not is related closely to the pressure magnitude,and there are no vortices for lower absolute pressure values,the number and the strength of the side-wall vortices increase as the absolute pressure values ***,based on statistical analyses,the side-wall vortex probability on the right side along the stream-wise direction is much higher than that on the opposite side for all operation cases,particularly single vortex probability,and the back-wall vortex probabilities are quite higher with values of more than 90%,meanwhile,the multi-vortices probability is much higher than that of the *** captured vortices have been qualitatively classified into different“vortex zones”:no vortex zones and vortex zones including transition,single-and *** Reynolds number and the absolute value pressure are the most important parameters which influence the existence and the number of these vortices,and the increase of the two parameters reduces the no vortex transition zone and causes bigger difference in the back-wall and side-wall vortex zones.

关键词： Evolution of subsurface vortices particle-image velocimetry(PIV) vortex probability closed pump intake

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A sparse matrix model-based optical proximity correction algorithm with model-based mapping between segments and control sites

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第5期12卷 436-442页

作者： Bin LIN xiao-lang yan Zheng shi Yi-wei yanG Institute of VLSI Design Zhejiang University Hangzhou 310027 China

Optical proximity correction (OPC) is a key step in modern integrated circuit (IC) *** quality of model-based OPC (MB-OPC) is directly determined by segment offsets after OPC ***,in conventional MB-OPC,the intensity of a control site is adjusted only by the movement of its corresponding segment;this scheme is no longer accurate enough as the lithography process *** the other hand,matrix MB-OPC is too time-consuming to become *** this paper,we propose a new sparse matrix MB-OPC algorithm with model-based mapping between segments and control *** put forward the concept of 'sensitive area'.When the Jacobian matrix used in the matrix MB-OPC is evaluated,only the elements that correspond to the segments in the sensitive area of every control site need to be calculated,while the others can be set to *** new algorithm can effectively improve the sparsity of the Jacobian matrix,and hence reduce the *** theoretical analysis and experiments show that the sparse matrix MB-OPC with model-based mapping is more accurate than conventional MB-OPC,and much faster than matrix MB-OPC while maintaining high accuracy.

关键词： Matrix sparsity Optical proximity correction (OPC) Convergence Segment Sensitive area

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Bioaccessibility and health risk assessment of hydrophobic organic pollutants in soils from four typical industrial contaminated sites in China

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Journal of Environmental Sciences 2025年第1期147卷 282-293页

作者： shi-Ping Ou xiao-Liang Liao Zi-Tao Huang yan-Cong Hu Zongwei Cai Zhi-Feng Chen Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and HealthSchool of Environmental Science and EngineeringGuangdong University of TechnologyGuangzhou 510006China State Key Laboratory of Environmental and Biological Analysis Department of ChemistryHong Kong Baptist UniversityHong Kong 999077China

There have been reports of potential health risks for people from hydrophobic organic pollutants,such as polycyclic aromatic hydrocarbons(PAHs),polychlorinated hydrocarbons(PCHs),and organophosphate flame retardants(OPFRs).When a contaminated site is used for residential housing or public utility and recreation areas,the soil-bound organic pollutantsmight pose a threat to human *** this study,we investigated the contamination profiles and potential risks to human health of 15 PAHs,6 PCHs,and 12 OPFRs in soils from four contaminated sites in *** used an in vitro method to determine the oral bioaccessibility of soil *** PAHswere found at concentrations ranging from26.4 ng/g to 987 ng/***(0.27-14.3 ng/g)and OPFRs(6.30-310 ng/g)were detected,but at low levels compared to earlier *** levels of PAHs,PCHs,and OPFRs released from contaminated soils into simulated gastrointestinal fluids ranged from 1.74%to 91.0%,2.51%to 39.6%,and 1.37%to 96.9%,*** on both spiked and unspiked samples,we found that the oral bioaccessibility of pollutantswas correlated with their logKow andmolecularweight,and the total organic carbon content and pH of *** in 13 out of 38 contaminated soil samples posed potential high risks to *** considering oral bioaccessibility,nine soils still posed potential risks,while the risks in the remaining soils became *** contribution of this paper is that it corrects the health risk of soil-bound organic pollutants by detecting bioaccessibility in actual soils from different contaminated sites.

关键词： Contaminated soil Hydrophobic organic pollutant Polycyclic aromatic hydrocarbon Oral bioaccessibility Risk assessment

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Inhibition of platelet aggregation by polyaspartoyl L-arginine and its mechanism

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Acta Pharmacologica Sinica 2004年第4期25卷 71-75页

作者： Yin-ye WANG, Zhi-yu TANG, Min DONG, xiao-yan LIU, shi-qi PENG2 Department of Pharmacology, Department of Medicinal Chemistry, 2 Schoolof Pharmaceutical Sciences, Peking University, Beijing 100083, China Department of Pharmacology School of Pharmaceutical Sciences Peking University 北京 100083 Department of Medicinal Chemistry School of Pharmaceutical Sciences Peking University 北京 100083

AIM: To observe the oral anti-platelet efficacy and the potential action mechanism of polyaspartoyl L-arginine (PDR), a new L-arginine rich compound. METHODS: Platelet aggregation was conducted by Born’s method; bleeding time was determined using tail’s bleeding time in mice; platelet adhesion was carried out with glass bottle method; nitric oxide (NO) was tested with Griess’ method; and cAMP, thromboxane B2 (TXB2) and 6-keto-PGF1α were assessed with commercial kits. RESULTS: The inhibition by PDR (15-60 mg/kg ig or 10 mg/kg iv) of platelet aggregation induced by adenosine diphosphate (ADP), collagen or thrombin at 1 h after oral administration or at 20 min after iv injection for rats (P<0.01), and its (15 mg/kg, ig) inhibition of ADP-induced platelet aggregation for rabbits during 6 h after administration were observed. PDR (15-60 mg/kg) prolonged the bleeding time of mice (P<0.05) and (30 mg/kg) increased NO concentration in plasma. On the other hand PDR did not change the contents of cAMP in platelet and TXB2 or 6-keto-PGF1α in plasma. CONCLUSION: PDR is a novel, oral effective platelet aggregation inhibitor and its action mechanism possibly related to increasing NO generation.

关键词： platelet aggregation bleeding time platelet adhesiveness polyaspartoyl L-arginine nitric oxide cyclic AMP Thromboxane B2 6-ketoprostaglandin F1 alpha

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miRNA-21-5p is an important contributor to the promotion of injured peripheral nerve regeneration using hypoxia-pretreated bone marrow-derived neural crest cells

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Neural Regeneration Research 2025年第1期20卷 277-290页

作者： Meng Cong Jing-Jing Hu yan Yu xiao-Li Li xiao-Ting Sun Li-Ting Wang Xia Wu Ling-Jie Zhu xiao-Jia yang Qian-Ru He Fei Ding Hai-yan shi School of Medicine Nantong UniversityNantongJiangsu ProvinceChina Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education and Coinnovation Center of Neuroregeneration Nantong UniversityNantongJiangsu ProvinceChina Department of Physiology Jiangsu Health Vocational CollegeNanjingJiangsu ProvinceChina Department of Pathology Affiliated Hospital of Nantong UniversityNantongJiangsu ProvinceChina Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair Affiliated Hospital of Nantong UniversityNantongJiangsu ProvinceChina

Our previous study found that rat bone marrow–derived neural crest cells(acting as Schwann cell progenitors)have the potential to promote long-distance nerve ***-based therapy can enhance peripheral nerve repair and regeneration through paracrine bioactive factors and intercellular ***,the complex contributions of various types of soluble cytokines and extracellular vesicle cargos to the secretome remain *** investigate the role of the secretome and extracellular vesicles in repairing damaged peripheral nerves,we collected conditioned culture medium from hypoxia-pretreated neural crest cells,and found that it significantly promoted the repair of sensory neurons damaged by oxygen-glucose *** mRNA expression of trophic factors was highly expressed in hypoxia-pretreated neural crest *** performed RNA sequencing and bioinformatics analysis and found that miR-21-5p was enriched in hypoxia-pretreated extracellular vesicles of neural crest ***,to further clarify the role of hypoxia-pretreated neural crest cell extracellular vesicles rich in miR-21-5p in axonal growth and regeneration of sensory neurons,we used a microfluidic axonal dissociation model of sensory neurons in vitro,and found that hypoxia-pretreated neural crest cell extracellular vesicles promoted axonal growth and regeneration of sensory neurons,which was greatly dependent on loaded ***,we constructed a miR-21-5p-loaded neural conduit to repair the sciatic nerve defect in rats and found that the motor and sensory functions of injured rat hind limb,as well as muscle tissue morphology of the hind limbs,were obviously *** findings suggest that hypoxia-pretreated neural crest extracellular vesicles are natural nanoparticles rich in ***-21-5p is one of the main contributors to promoting nerve regeneration by the neural crest cell *** helps to explain the mechanism of action of the secretome and e

关键词： axotomy cell-free therapy conditioned medium extracellular vesicles hypoxic preconditioning microRNA oxygen-glucose deprivation peripheral nerve injury Schwann cell precursors

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Degradation of Microbes for the Crude Oil Contaminants

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地球科学进展 2004年第S1期19卷 516-519页

作者： LIU xiao-yan, shi Peng-fei, SUN De-zhi (Science school, Harbin Institute of Technology, Harbin 150001, China)

Production and storage-transportation of crude oil can not only give rise to soil pollution but also destroy ecological environment. Degradation of microbes for oily soil was studied with the instnunent, Geofina Hydrocarbon Meter (GHM), by experimental analysis qualitatively and quantitatively in the paper. Analytical result showed that the crude oil could be considerably degraded by eating-oil microbes in oily soil and the number of eating-oil microbes increased while the working hours of oil-well risi...

关键词： Microbes Crude oil Contaminants Degradation Experimental analysis

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Utilizing BP neural networks to accurately reconstruct the tritium depth profile in materials for BIXS

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Nuclear Science and Techniques 2025年第1期36卷 103-114页

作者： Chen Zhao Wei Jin yan shi Chang-An Chen Yi-Ying Zhao Institute of Materials China Academy of Engineering PhysicsJiangyou 621908China

β-ray-induced X-ray spectroscopy(BIXS)is a promising method for tritium detection in solid materials because of its unique advantages,such as large detection depth,nondestructive testing capabilities,and low requirements for sample ***,high-accuracy reconstruction of the tritium depth profile remains a significant challenge for this *** this study,a novel reconstruction method based on a backpropagation(BP)neural network algorithm that demonstrates high accuracy,broad applicability,and robust noise resistance is *** average reconstruction error calculated using the BP network(8.0%)was much lower than that obtained using traditional numerical methods(26.5%).In addition,the BP method can accurately reconstruct BIX spectra of samples with an unknown range of tritium and exhibits wide applicability to spectra with various tritium ***,the BP network demonstrates superior accuracy and stability compared to numerical methods when reconstructing the spectra,with a relative uncertainty ranging from 0 to 10%.This study highlights the advantages of BP networks in accurately reconstructing the tritium depth profile from BIXS and promotes their further application in tritium detection.

关键词： β-ray-induced X-ray spectroscopy Tritium detection BP network Ridge regression Reconstruction problem

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Hepatitis B virus X protein regulates the mEZH2 promoter via the E2F1-binding site in AML12 cells

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Chinese Journal of Cancer 2011年第4期30卷 273-279页

作者： xiao-yan shi Ying-Ying Zhang xiao-Wei Zhou Jian-Sheng Lu Ze-Kun Guo Pei-Tang Huang Beijing Institute of Biotechnology Beijing 100071 P. R. China College of Life Sciences Northwest A&F University Yangling Shaanxi 712100 P. R. China.

Histone lysine methyltransferase EZH2 has been reported to be frequently overexpressed in hepatocellular carcinoma(HCC) tissues and associated with ***,the exact mechanism of EZH2 up-regulation in HCC has not been *** this study,we used murine hepatocyte AML12 cells to investigate the role of hepatitis B virus X protein(HBx) in regulating the expression of *** blot analysis demonstrated that the expression level of mEZH2 protein in AML12 cells was up-regulated by HBx in a dose-dependent *** further investigate the mechanism of mEZH2 overexpression,the 2500 bp regulatory sequence upstream from the first exon of the mEZH2 gene was amplified from AML12 genomic DNA and constructed into a luciferase reporter *** luciferase activity of the mEZH2 promoter significantly increased in AML12 cells co-transfected with HBx plasmid,and deleting the-486/-214 promoter region decreased HBx-induced mEZH2 promoter activation by nearly 50%.The-486/-214 region was then analyzed in the TRANSFAC 6.0 database and a typical E2F1-binding site was *** of this E2F1-binding site or knockdown of E2F1 expression by RNAi led to a dramatic decrease in HBx-induced activation of the mEZH2 promoter and mEZH2 overexpression in AML12 *** results provide evidence that HBx up-regulates mEZH2 expression by transactivating the mEZH2 promoter through E2F1 transcription factor,thereby providing new epigenetic evidence for the carcinogenic effect of HBx.

关键词：乙型肝炎病毒肝细胞癌结合位点组蛋白启动子 blot分析过度表达质粒构建

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RNA interference of pax2 inhibits growth of transplanted human endometrial cancer cells in nude mice

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Chinese Journal of Cancer 2011年第6期30卷 400-406页

作者： Li-Ping Zhang xiao-yan shi Chang-Yin Zhao Yong-Zhen Liu Ping Cheng Department of Gynecology and Obstetrics Taihe Hospital Hubei Medical University Shiyan Hubei 442000 P. R. China Central Laboratory Central Hospital of Wuhan Tongji Medical College Huazhong University of Science and Technology Wuhan Hubei 430014 P. R. China.

The development of human endometrial carcinoma(HEC) is a complex pathologic process involves several oncogenes and tumor suppressor *** full-length paired-box gene 2(pax2),a recently discovered oncogene,promotes cell proliferation and growth and inhibits apoptosis of HEC ***,we examined the effect of pax2 small interfering RNA(siRNA) on the growth of transplanted HEC cells in nude *** expression of Pax2 in 21 cases of normal endometrium and 38 cases of HEC was examined by immohistochemistry(IHC).HEC models were developed by subcutaneously transferring HEC cells into nude mice,followed by treatment with empty lentivirus vector,lentivirus vector-based pax2 siRNA,and phosphate buffered saline,*** weeks later,tumor size was measured,tumor inhibition rate was calculated,and histological analyses were conducted after staining with hematoxylin and *** expression of Pax2 and Bcl-2 was detected by Western blot;proliferating cell nuclear antigen(PCNA) was detected by *** differences were observed in the positive rate of Pax2 between normal endometrium and HEC(14.2% vs.60.5%,P<0.01).The expression index of Pax2 in well differentiated tumors was 1.88±1.68,much lower than that in tumors of moderate(3.07±1.96,P<0.05) or poor differentiation(5.45±2.76,P<0.01).Tumor necrosis increased,nuclear basophilia stain decreased,tumor growth was inhibited,and PCNA,Pax2,and Bcl-2 expression was reduced in HEC models treated with pax2 *** results indicate that Pax2 expression is related to HEC tumor biology with the increased expression of Pax2 correlated to ***2 siRNA down-regulates Pax2 expression and inhibits tumorigenesis of HEC in nude mice,possibly due to cell apoptosis and the inhibition of tumor proliferation induced by down-regulation of Bcl-2.

关键词： siRNA 子宫内膜癌小干扰RNA 肿瘤生长细胞移植癌细胞裸鼠免疫组化检测

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Revealing and predicting the long-term biomechanical response of orthokeratology by developing a patient-specific computational model

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Science China(Physics,Mechanics & Astronomy) 2025年第1期68卷 152-164页

作者： Yifeng Li Zhuoran yang Ziming yan Huibin shi Zhanli Liu Kaijie Wang Department of Engineering Mechanics School of Aerospace EngineeringTsinghua UniversityBeijing 100084China Beijing Tongren Eye Center Beijing Tongren HospitalCapital Medical UniversityBeijing Ophthalmology&Visual Sciences Key LabBeijing 100730China

Orthokeratology(OK)is widely used for effective myopia correction and ***,the incomplete understanding of its biomechanical mechanisms makes OK lens fitting rely heavily on clinician judgment,complicating accurate predictions of treatment *** this paper,we performed clinical experiments and numerical analysis to study corneal deformation modes and long-term changes in central corneal *** experiments were conducted on 194 Chinese myopic patients under OK treatment for 3 *** on the experimental data,a patient-specific computational biomechanical model for OK was established and ***,the anisotropic mechanical properties of the cornea were incorporated into the model to describe the significant difference between its shear modulus(29.5 kPa)and tensile modulus(768.4 kPa).Additionally,a viscohyperelastic material model with a prolonged corneal relaxation time of 5.6 h was developed to capture the long-term deformation *** results show that corneal thickness reduction in OK is primarily due to out-of-plane shear deformation,influenced by the cornea’s low shear *** the extended corneal relaxation time is crucial for predicting long-term biomechanical *** computational model effectively captures long-term changes in central corneal thickness,potentially improving OK lens fitting accuracy.

关键词： orthokeratology computational biomechanical model long-term viscoelasticity myopia correction

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