153 results on '"Xiaohua Wang"'
Search Results
2. 21-year trend of new leprosy cases in Guangdong, China: An analysis of surveillance data from 2000 to 2020.
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Xiaohua Wang, Xiuqiu Lin, Peizhen Zhao, Lei Chen, Daochen Zheng, and Bin Yang
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HANSEN'S disease , *DATA analysis - Published
- 2023
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3. Numerical simulation of the Trichel pulse characteristics in SF6/N2 gas mixtures.
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Qingqing Gao, Xiaohua Wang, Kazimierz Adamiak, Aijun Yang, Dingxin Liu, Mingzhe Rong, and Jiawei Zhang
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POISSON'S equation , *GAS mixtures , *ELECTRIC discharges , *COMPUTER simulation , *ELECTRIC fields , *ELECTRON diffusion - Abstract
The paper presents the results of a numerical simulation of the effects of N2 on the characteristics of Trichel pulses in SF6 at 0.4 MPa. The simulation was performed in a 2D axisymmetric geometry assuming a three species discharge model for the applied voltage on the discharge electrode to be −25 kV. Three drift-diffusion equations coupled with Poisson's equation are considered to determine the dynamic behavior of Trichel pulses and the temporal and spatial distributions of charged species. The reduced ionization coefficient, the reduced attachment coefficient, the electron mobility, and the electron diffusion coefficient of SF6/N2 mixtures are obtained by solving the two-term Boltzmann equations. The content of N2 varies from 20% to 80%. The distribution of three charged species and the reduced electric field at the discharge tip are presented at different instants of time to explain the formation mechanism of the Trichel pulses in SF6/N2 mixtures. The time-dependent current, the total number of electrons, the positive ions, and the negative ions as well as the reduced electric field at the discharge tip under different SF6/N2 mixtures are analyzed to investigate the sensitivities of these properties to the N2 content. [ABSTRACT FROM AUTHOR]
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- 2020
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4. Two-level attention with two-stage multi-task learning for facial emotion recognition.
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Xiaohua, Wang, Muzi, Peng, Lijuan, Pan, Min, Hu, Chunhua, Jin, and Fuji, Ren
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COMPUTER multitasking , *FACIAL expression , *EMOTION recognition , *FEATURE extraction , *DISCRETE choice models , *ESTIMATION theory , *RECURRENT neural networks , *ATTENTION - Abstract
• Two-level attention mechanism is proposed to extract position-level and layer-level features from static facial expression adaptively. • Two-stage multi-task learning structure is proposed to learn the feature representation on the discrete model to supplement the feature representation on the dimensional model. • A unified framework is proposed for facial emotion recognition on the dimensional model. Compared with facial emotion estimation on categorical model, dimensional emotion estimation can describe numerous emotions more accurately. Most prior works of dimensional emotion estimation only considered laboratory data and used video, speech or other multi-modal features. Compared with other modal data, static images has superiorities of accessibility, which is more conducive to the emotion estimation in real world. In this paper, a two-level attention with two-stage multi-task learning (2Att-2Mt) framework is proposed for facial emotion estimation on only static images. Firstly, the features of corresponding region (position level features) are extracted and enhanced automatically by first-level attention mechanism. Then, we utilize Bi-directional Recurrent Neural Network (Bi-RNN) with self-attention (second-level attention) to make full use of the relationship features of different layers (layer-level features) adaptively. And then, we propose a two-stage multi-task learning structure, which exploits categorical representations to ameliorate the dimensional representations and estimate valence and arousal simultaneously in view of the inherent complexity of dimensional representations and correlation of the two targets. The quantitative results conducted on AffectNet dataset show significant advancement on Concordance Correlation Coefficient(CCC) and Root Mean Square Error (RMSE), illustrating the superiority of the proposed framework. Besides, extensive comparative experiments have also fully demonstrated the effectiveness of different components (2Att and 2Mt) in our framework. [ABSTRACT FROM AUTHOR]
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- 2019
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5. 4-Octyl Itaconate Activates Nrf2 Signaling to Inhibit Pro-Inflammatory Cytokine Production in Peripheral Blood Mononuclear Cells of Systemic Lupus Erythematosus Patients.
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Chun Tang, Xiaohua Wang, Yingying Xie, Xiaoyan Cai, Na Yu, Yudan Hu, and Zhihua Zheng
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SYSTEMIC lupus erythematosus , *CYSTEINE , *TUMOR necrosis factors , *MICRORNA , *NF-kappa B - Abstract
Background/Aims: Increased production of multiple pro-inflammatory cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6, plays an essential pathogenic role in the progression of systemic lupus erythematosus (SLE). Recent studies have characterized itaconate as a novel and potent nuclear-factor-E2-related factor 2 (Nrf2) activator that activates Nrf2 signaling by alkylating cysteine residues on Keap1 (Kelch-like ECH-associated protein 1). Methods: THP-1 human macrophages and peripheral blood mononuclear cells (PBMCs) of SLE patients were treated with 4-octyl itaconate (OI). Nrf2 signaling activation was tested by qPCR assay and western blotting. mRNA expression and the production of multiple pro-inflammatory cytokines were tested by qPCR and enzyme-linked immunosorbent assays, respectively. Nuclear factor (NF)-κB activation was tested by the p65 DNA-binding assay. Results: We demonstrated that OI, the cell-permeable derivative of itaconate, induced Keap1-Nrf2 dissociation, Nrf2 protein accumulation, and nuclear translocation, which enabled the transcription and expression of multiple Nrf2-dependentantioxidant enzymes (heme oxygenase-1, NAD(P)H:quinone oxidoreductase 1, and glutamate-cysteine ligase modifier subunit) in THP-1 human macrophages. OI also induced significant Nrf2 activation in SLE patient-derived PBMCs. OI pretreatment inhibited mRNA expression and the production of multiple pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) in SLE patient-derived PBMCs and lipopolysaccharide (LPS)-activated THP-1 cells. OI potently inhibited NF-κB activation in SLE patient-derived PBMCs and LPS-activated THP-1 cells. Importantly, Nrf2 silencing (by targeted short hairpin RNA) or knockout (by CRISPR/Cas9 gene-editing method) almost abolished OIinduced anti-oxidant and anti-inflammatory actions in SLE patient-derived PBMCs and LPSactivated THP-1 cells. Conclusion: OI activates Nrf2 signaling to inhibit the production of pro-inflammatory cytokines in human macrophages and SLE patient-derived PBMCs. OI and itaconate could have important therapeutic value for the treatment of SLE. [ABSTRACT FROM AUTHOR]
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- 2018
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6. Time-frequency analysis of PD-induced UHF signal in GIS and feature extraction using invariant moments.
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Xi Li, Xiaohua Wang, Dingli Xie, Xinqiao Wang, Aijun Yang, and Mingzhe Rong
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ELECTRIC switchgear , *PARTIAL discharge measurement , *TIME-frequency analysis , *FEATURE extraction , *GAS-insulated cables , *ENERGY density , *SUPPORT vector machines - Abstract
The ultra-high-frequency (UHF) method is efficient in partial discharges (PDs) detection in gas-insulated switchgear (GIS). The features extraction of UHF signals is significant for propagation characteristics analysis and PD pattern classification. The PD-induced UHF signals are acquired by the internal UHF sensors in an actual 252 kV L-shaped GIS. The short-time Fourier transform method is applied to process UHF signals and describe the propagation characteristics in L-shaped GIS. Hu's invariant moments of energy density distribution are extracted as features in time-frequency plane. The features are utilised to discriminate different PD defect patterns in actual GIS model by the support vector machine classifier and achieve good results. Finally, a novel system of features extraction and classification of UHF signals is summarised. [ABSTRACT FROM AUTHOR]
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- 2018
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7. Failure Prognosis of High Voltage Circuit Breakers with Temporal Latent Dirichlet Allocation.
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Gaoyang Li, Xiaohua Wang, Aijun Yang, Mingzhe Rong, and Kang Yang
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HIGH voltages , *ELECTRIC power distribution grids , *SEQUENTIAL analysis , *DIRICHLET forms , *ELECTRON-transfer catalysis - Abstract
The continual accumulation of power grid failure logs provides a valuable but rarely used source for data mining. Sequential analysis, aiming at exploiting the temporal evolution and exploring the future trend in power grid failures, is an increasingly promising alternative for predictive scheduling and decision-making. In this paper, a temporal Latent Dirichlet Allocation (TLDA) framework is proposed to proactively reduce the cardinality of the event categories and estimate the future failure distributions by automatically uncovering the hidden patterns. The aim was to model the failure sequence as a mixture of several failure patterns, each of which was characterized by an infinite mixture of failures with certain probabilities. This state space dependency was captured by a hierarchical Bayesian framework. The model was temporally extended by establishing the long-term dependency with new co-occurrence patterns. Evaluation of the high voltage circuit breakers (HVCBs) demonstrated that the TLDA model had higher fidelities of 51.13%, 73.86%, and 92.93% in the Top-1, Top-5, and Top-10 failure prediction tasks over the baselines, respectively. In addition to the quantitative results, we showed that the TLDA can be successfully used for extracting the time-varying failure patterns and capture the failure association with a cluster coalition method. [ABSTRACT FROM AUTHOR]
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- 2017
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8. Intravenous infusion umbilical cord-derived mesenchymal stem cell in primary immune thrombocytopenia: A two-year follow-up.
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XIAOHUA WANG, XIAOGUANG YIN, WEI SUN, JIN BAI, YAWEN SHEN, QIANG AO, YONGQUAN GU, and YING LIU
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INTRAVENOUS therapy , *UMBILICAL cord , *MESENCHYMAL stem cells , *IDIOPATHIC thrombocytopenic purpura , *STEM cells - Abstract
Four patients with chronic refractory immune thrombocytopenic purpura (ITP) received human umbilical cord-derived mesenchymal stem cells (hUC-MSCs). The hUC-MSC dose was 5x107 to 1x108. Complete remission (CR) was achieved in three patients in 12 months and one patient in 24 months. Three patients received the second hUC-MSC transplantation with the same dose. The median time between hUC-MSC transplantation and response was 12.5 days (range, 7-16). There were no severe adverse events during and post hUC-MSC transplantation. During follow-up (median, 17 months; range, 13-24) no other immunosuppressive drugs were used post-first hUC-MSCs transplantation. In conclusion, hUC-MSC transplantation is a reasonable salvage treatment in chronic refractory ITP. Prospective randomized large-scale clinical trials are needed to further elucidate the efficacy of hUC-MSCs transplantation therapy on ITP. [ABSTRACT FROM AUTHOR]
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- 2017
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9. HIF-2α affects proliferation and apoptosis of MG-63 osteosarcoma cells through MAPK signaling.
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YUQIANG WANG, XIAOHUA WANG, XUETAO SU, and TIANSHENG LIU
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OSTEOSARCOMA , *CELL lines , *APOPTOSIS , *CELL death , *SMALL interfering RNA - Abstract
The present study explored the mechanism of hypoxia-inducible factor (HIF)-2α in proliferation and apoptosis of the osteosarcoma cell line, MG-63. Cells were treated with small interfering RNA (siRNA) against HIF-2α (silenced group) or without siRNA (control group). Cell viability of MG-63 in the silenced and the control groups was determined by MTT assay; cell apoptosis was measured by flow cytometry; the expression of HIF-2α and mitogen-activated protein kinase (MAPK)-p38 were measured by western blotting. According to MTT assay, 48 h after siRNA transfection, compared with the control group, cells in the silenced group significantly declined in quantity and the number of apoptotic cells increased significantly. The expression of HIF-2α and MAPK-p38 were significantly decreased (P<0.05). In conclusion, knockdown of HIF-2α in the osteosarcoma cell line reduced the proliferation of cancer cells and increased apoptosis. These effects likely occurred through the MAPK-p38 signaling pathway. [ABSTRACT FROM AUTHOR]
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- 2017
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10. Risk factors of the stigma towards psychiatric patients among primary healthcare workers in China: a county study.
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Yang Wang, Xiaohua Wang, Weijun Zhang, Xiaoyun Liang, Donghua Tian, and Zhiyong Qu
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PSYCHOTHERAPY patients , *MENTAL health , *BIVARIATE analysis , *MEDICAL education , *MASS media - Abstract
Background: Attitude towards psychiatric patients among healthcare workers has an impact on quality of medical care and rehabilitation of patients. In China, primary healthcare workers play an important role in mental health care, but little is known about the attitude of them towards psychiatric patients. This study aims to examine the risk factors associated with stigma among primary healthcare workers in West China. Methods: This cross-sectional study randomly recruited 395 primary healthcare workers in Mianzhu County, China. Data were collected via self-reported questionnaires. Descriptive analyses, bivariate analyses, and hierarchical linear regressions were performed by SPSS 17.0 to test the factors that accounted for the variation of stigma towards psychiatric patients. Results: Several risk factors were confirmed, including the satisfaction of income, work experience in psychiatric/ psychological departments, rehabilitation of patients, contact quality, and the attitude of mass media. However, demographic factors, the rest of work-related factors, and contact frequency might not be related with primary healthcare workers' attitude towards psychiatric patients. Conclusions: The findings suggested that the quality of contact between primary healthcare workers and psychiatric patients be enhanced in order to decrease the stigma of healthcare staff. On-the-job training and institutional medical education needs a further exploration and development. [ABSTRACT FROM AUTHOR]
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- 2017
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11. Research on China’s rural household energy consumption – Household investigation of typical counties in 8 economic zones.
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Xiaohua, Wang, Kunquan, Li, Hua, Li, Di, Bai, and Jingru, Liu
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ENERGY consumption , *BIOMASS energy , *DATA analysis , *RENEWABLE energy sources , *ENVIRONMENTAL policy - Abstract
Rural household energy consumption is an important component of national energy consumption and plays an important role in rural social and ecological environment developments. In this paper, energy consumption of 1440 households in 8 typical counties of 8 China's economic zones was investigated. The investigation data analysis revealed significant difference of different economic zones in rural household energy consumption level and structure. For 8 studying counties, the annual average energy consumption per capita was 26.7 GJ, 10.4 GJ the lowest (Shanghang County) and 86.6 GJ the highest (Shulan County). In energy consumption, straw, biogas, fuel wood and electricity accounted for 44.33%, 23.13%, 12.79% and 9.61%, respectively. Rural families with high incomes preferred commercial energies (e.g. electricity and liquefied petroleum gas (LPG)) to biomass energy (e.g. straw and fuel wood). The traditional biomass energy is still the main energy source for China's rural household. Research results provide references to understand current situations and future development of China's rural household energy consumption, and formulate related energy and environmental policies. [ABSTRACT FROM AUTHOR]
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- 2017
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12. Induced membrane technique for the treatment of chronic hematogenous tibia osteomyelitis.
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Xiaohua Wang, Zhen Wang, Jingshu Fu, Ke Huang, Zhao Xie, Wang, Xiaohua, Wang, Zhen, Fu, Jingshu, Huang, Ke, and Xie, Zhao
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OSTEOMYELITIS , *BONE grafting , *POLYMETHYLMETHACRYLATE , *BONES , *DEBRIDEMENT , *OSTEOMYELITIS treatment , *TIBIA surgery , *BONE cements , *ANTIBIOTICS , *CHRONIC diseases , *LONGITUDINAL method , *TIBIA , *TREATMENT effectiveness , *THERAPEUTICS - Abstract
Background: Chronic hematogenous osteomyelitis often results from the improper treatment of acute hematogenous osteomyelitis. At present, there is lack of uniform standards for the treatment, and the clinical features of the disease are unclear. The purpose of this study was to explore the clinical efficacy and complications of chronic hematogenous tibia osteomyelitis treated with the induced membrane technique.Methods: A retrospective analysis of the chronic hematogenous tibia osteomyelitis patients in our department admitted from January 2013 to February 2014 and treated with the induced membrane two-stage surgical technique was performed. The defects were filled with antibiotic-loaded polymethyl methacrylate (PMMA) cement after radical debridement, and bone grafts were implanted to repair the defects after 6 to 8 weeks.Results: A total of 15 cases were admitted in this study, including 13 men and 2 women with a mean age of 34 years (6 to 51). The mean duration of bone infection was 142 months (3 to 361). All patients were cured with an average follow-up of 25 months (24 to 28). Radiographic bone union occurred in 5.3 months (3 to 8), and full weight bearing occurred in 6.7 months (4 to 10). No recurrence of infection was noted at the last follow-up. Two cases required repeated debridement before grafting due to recurrent infection. One patient had a small bone diameter due to insufficient grafting, and one patient had limitation of knee activity.Conclusions: The induced membrane technique for the treatment of chronic hematogenous tibia osteomyelitis is an effective and reliable method. Thorough debridement and wound closure at the first stage is essential for infection control as well as sufficient grafting at the second stage to ensure bone union. [ABSTRACT FROM AUTHOR]- Published
- 2017
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13. UHF Signal Processing and Pattern Recognition of Partial Discharge in Gas-Insulated Switchgear Using Chromatic Methodology.
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Xiaohua Wang, Xi Li, Mingzhe Rong, Dingli Xie, Dan Ding, and Zhixiang Wang
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UHF devices , *SIGNAL processing , *PATTERN recognition systems , *PARTIAL discharges , *ELECTRIC insulators & insulation - Abstract
The ultra-high frequency (UHF) method is widely used in insulation condition assessment. However, UHF signal processing algorithms are complicated and the size of the result is large, which hinders extracting features and recognizing partial discharge (PD) patterns. This article investigated the chromatic methodology that is novel in PD detection. The principle of chromatic methodologies in color science are introduced. The chromatic processing represents UHF signals sparsely. The UHF signals obtained from PD experiments were processed using chromatic methodology and characterized by three parameters in chromatic space (H, L, and S representing dominant wavelength, signal strength, and saturation, respectively). The features of the UHF signals were studied hierarchically. The results showed that the chromatic parameters were consistent with conventional frequency domain parameters. The global chromatic parameters can be used to distinguish UHF signals acquired by different sensors, and they reveal the propagation properties of the UHF signal in the L-shaped gas-insulated switchgear (GIS). Finally, typical PD defect patterns had been recognized by using novel chromatic parameters in an actual GIS tank and good performance of recognition was achieved. [ABSTRACT FROM AUTHOR]
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- 2017
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14. Influence of metallic vapours on thermodynamic and transport properties of two-temperature air plasma.
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Linlin Zhong, Xiaohua Wang, Cressault, Yann, Teulet, Philippe, and Mingzhe Rong
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THERMODYNAMIC equilibrium , *ELECTRODES , *METAL vapors , *PLASMA gases , *TEMPERATURE effect - Abstract
The metallic vapours (i.e., copper, iron, and silver in this paper) resulting from walls and/or electrode surfaces can significantly affect the characteristics of air plasma. Different from the previous works assuming local thermodynamic equilibrium, this paper investigates the influence of metallic vapours on two-temperature (2 T) air plasma. The 2 T compositions of air contaminated by Cu, Fe, and Ag are first determined based on Saha's and Guldberg-Waage's laws. The thermodynamic properties (including mass density, specific enthalpy, and specific heat) are then calculated according to their definitions. After determining the collision integrals for each pair of species in air-metal mixtures using the newly published methods and source data, the transport coefficients (including electrical conductivity, viscosity, and thermal conductivity) are calculated for air-Cu, air-Fe, and air-Ag plasmas with different non-equilibrium degree θ (Te/Th). The influences of metallic contamination as well as non-equilibrium degree are discussed. It is found that copper, iron, and silver exist mainly in the form of Cu2, FeO, and AgO at low temperatures. Generally, the metallic vapours increase mass density at most temperatures, reduce the specific enthalpy and specific heat in the whole temperature range, and affect the transport properties remarkably from 5000K to 20 000 K. The effect arising from the type of metals is little except for silver at certain temperatures. Besides, the departure from thermal equilibrium results in the delay of dissociation and ionization reactions, leading to the shift of thermodynamic and transport properties towards a higher temperature. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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15. Theoretical study of the decomposition pathways and products of C5- perfluorinated ketone (C5 PFK).
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Yuwei Fu, Xiaohua Wang, Xi Li, Aijun Yang, Guohui Han, Yanhui Lu, Yi Wu, and Mingzhe Rong
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KETONES , *CHEMICAL decomposition , *DENSITY functional theory - Abstract
Due to the high global warming potential (GWP) and increasing environmental concerns, efforts on searching the alternative gases to SF6, which is predominantly used as insulating and interrupting medium in high-voltage equipment, have become a hot topic in recent decades. Overcoming the drawbacks of the existing candidate gases, C5- perfluorinated ketone (C5 PFK) was reported as a promising gas with remarkable insulation capacity and the low GWP of approximately 1. Experimental measurements of the dielectric strength of this novel gas and its mixtures have been carried out, but the chemical decomposition pathways and products of C5 PFK during breakdown are still unknown, which are the essential factors in evaluating the electric strength of this gas in high-voltage equipment. Therefore, this paper is devoted to exploring all the possible decomposition pathways and species of C5 PFK by density functional theory (DFT). The structural optimizations, vibrational frequency calculations and energy calculations of the species involved in a considered pathway were carried out with DFT-(U)B3LYP/6-311G(d,p) method. Detailed potential energy surface was then investigated thoroughly by the same method. Lastly, six decomposition pathways of C5 PFK decomposition involving fission reactions and the reactions with a transition states were obtained. Important intermediate products were also determined. Among all the pathways studied, the favorable decomposition reactions of C5 PFK were found, involving C-C bond ruptures producing Ia and Ib in pathway I, followed by subsequent C-C bond ruptures and internal F atom transfers in the decomposition of Ia and Ib presented in pathways II + III and IV + V, respectively. Possible routes were pointed out in pathway III and lead to the decomposition of IIa, which is the main intermediate product found in pathway II of Ia decomposition. We also investigated the decomposition of Ib, which can undergo unimolecular reactions to give the formation of IVa, IVb and products of CF3 + CF-CF3 in pathway IV. Although IVa is dominant to a lesser extent due to its relative high energy barrier, its complicated decomposition pathway V was also studied and CF3, C=CF2 as well as C-CF3 species were found as the ultimate products. To complete the decomposition of C5 PFK, pathway VI of Ic decomposition was fully explored and the final products were obtained. Therefore, the integrate decomposition scheme of C5 PFK was proposed, which contains six pathways and forty-eight species (including all the reactants, products and transition states). This work is hopeful to lay a theoretical basis for the insulating properties of C5 PFK. [ABSTRACT FROM AUTHOR]
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- 2016
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16. The growth and photovoltaic properties of Si nanowires and ZnO nanowires hetero-branched structures.
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Ruxue Li, Xiaohua Wang, Xuan Fang, Dongxu Zhao, Haifeng Zhao, Ligong Zhang, Dan Fang, Jinhua Li, Xueying Chu, Jilong Tang, Xiaohui Ma, and Zhipeng Wei
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NANOWIRES , *ZINC oxide , *SILICON , *ELECTROFORMING , *ELECTRODES - Abstract
Branched ZnO nanowires have been fabricated on p type Si nanowires by electrodeposition and formed a Si nanowires and ZnO nanowires branched core-shell structure. In these deposition process, Si nanowires could be used as the work electrode for ZnO directly depositing. The morphologies and growth region of ZnO could be controlled by adjusting the applied potential and deposition time. The structural and optical characterizations showed that ZnO nanowires synthesized on Si nanowires have the same physics property as synthesized on other conductive substrates and the optimal condition for ZnO growth. The I-V measurement based on the Si and ZnO p-n heterojunctions showed a typical semiconductor rectification characteristic, and the J-V measurement result indicated energy efficiency was 1.1%. [ABSTRACT FROM AUTHOR]
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- 2016
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17. Near-field acousto monitoring shear interactions inside a drop of fluid: The role of the zero-slip condition.
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Xiaohua Wang, Fernandez, Rodolfo, Nan Li, Hsien-Chih Hung, Venkataraman, Anuradha, Nordstrom, Richard, and La Rosa, Andres H.
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NEAR-fields , *ACOUSTICS , *NANOSTRUCTURED materials , *VISCOSITY , *MECHANICS (Physics) - Abstract
A full understanding of nanometer-range (near-field) interactions between two sliding solid boundaries, with a mesoscopic fluid layer sandwiched in between, remains challenging. In particular, the origin of the blue-shift resonance frequency experienced by a laterally oscillating probe when approaching a substrate is still a matter of controversy. A simpler problem is addressed here, where a laterally oscillating solid probe interacts with a more sizable drop of fluid that rests on a substrate, aiming at identifying interaction mechanisms that could also be present in the near-field interaction case. It is found that the inelastic component of the probe-fluid interaction does not constitute the main energy-dissipation channel and has a weak dependence on fluid's viscosity, which is attributed to the zero-slip hydrodynamic condition. In contrast, the acoustic signal engendered by the fluid has a stronger dependence on the fluid's viscosity (attributed also to the zero-slip hydrodynamic condition) and correlates well with the probe's resonance frequency red-shift. We propose a similar mechanism happens in near field experiments, but a blue-shift in the probe's resonance results as a consequence of the fluid molecules (subjected to the zero-slip condition at both the probe and substrate boundaries) exerting instead a spring type restoring force on the probe. [ABSTRACT FROM AUTHOR]
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- 2016
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18. N-doped TiO2 Nanotubes as an Effective Additive to Improve the Catalytic Capability of Methanol Oxidation for Pt/Graphene Nanocomposites.
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Xiaohua Wang, Yueming Li, Shimin Liu, and Long Zhang
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OXIDATION of methanol , *ELECTRICAL properties of titanium dioxide , *CATALYSTS - Abstract
N-doped TiO2 nanotubes have been prepared as additives to improve the catalytic capability of Pt/graphene composites in methanol oxidation reactions. Electrochemical experiments show that the catalytic performance of Pt/graphene composites has been greatly improved by the introduction of N-doped TiO2 nanotubes. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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19. Induction of granulation tissue for the secretion of growth factors and the promotion of bone defect repair.
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Xiaohua Wang, Fuda Wei, Fei Luo, Ke Huang, and Zhao Xie
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ALKALINE phosphatase , *ANIMAL experimentation , *BONE diseases , *ENZYME-linked immunosorbent assay , *GRANULATION tissue , *GROWTH factors , *HISTOLOGY , *ORTHOPEDIC surgery , *PERIOSTEUM , *RABBITS , *RESEARCH funding , *T-test (Statistics) , *DATA analysis software , *KRUSKAL-Wallis Test , *ONE-way analysis of variance ,TREATMENT of bone diseases - Abstract
Background: The use of the Masquelet technique in the repair of large bone defects has gained increased acceptance in recent years. The core of this technique is the induction of granulation tissue membrane formation and the implantation of an autologous cancellous bone to reconstruct bone defects in the membrane. In this study, we purpose to explore the structure of induced membrane and the content of growth factors as well to compare between the structure and the effects on osteogenesis of induced membranes and the periosteum in animal models. Methods: Bilateral radial bone defects were generated in 32 healthy adult rabbits. The defects were implanted with bone cement. The induced membranes and periosteum were removed after 2,4, 6, and 8 weeks. Thereafter, hematoxylin-eosin staining (HE) and an enzyme-linked immunosorbent assay (ELISA) were performed to detect vascular endothelial growth factor (VEGF), angiotensin II (ANG-II), bone morphogenetic protein 2 (BMP2), fibroblast growth factor 2 (FGF2), and prostaglandin E2 (PGE2). Proteins isolated from total cell lysates were cultured with mesenchymal stem cells to test the cell proliferation and alkaline phosphatase activity using epimysium as a control. Results: The induced membrane and periosteum exhibited similar structures and growth factor levels after 4 and 6 weeks. The highest concentration of BMP-2 and VEGF in the induced membranes occurred in week 6, and FGF-2 and ANG-II concentrations peaked in week 4. The thickness and vascular density of induced membranes gradually decreased with time. Conclusion: Induced membrane matured between the 4th and the 6th week and secreted growth factors to promote osteogenesis. The matured induced membrane and periosteum had similar structures and abilities to promote the osteogenesis of mesenchymal stem cells. However, the induced membrane was thicker than the periosteum. [ABSTRACT FROM AUTHOR]
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- 2015
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20. The Symptoms of Posttraumatic Stress Disorder and Depression Among Adult Earthquake Survivors in China.
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Jing Guo, Xiaohua Wang, Jiaqi Yuan, Weijun Zhang, Donghua Tian, and Zhiyong Qu
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- 2015
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21. Detection of Broad Bean Diseases by Fourier Transform Infrared Spectroscopy Combined with Curve Fitting.
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Xiaohua WANG, Gang LIU, Quanhong OU, Xiangping ZHOU, Jianming HAO, Jianhong LIU, and Luxiang WANG
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FOURIER transform infrared spectroscopy , *CEPSTRUM analysis (Mechanics) , *FAVA bean diseases & pests , *FAVA bean yield , *CURVE fitting - Abstract
Abstract Fourier transform infrared (FTIR) spectroscopy was used to study diseased leaves in broad bean. Results showed that the infrared spectra of different broad bean diseased leaves were similar, which were mainly made up of the vibrational absorption bands of protein, lipid and pdysaccharide. There were minor differences including the spectral peak position, peak shape and the absorption intensity in the range of 1 800-1 300 cm-1. There were obvious differences among their second derivative spectra in the range of 1 800-1 300 cm-1. After the procedure of the Fourier self-deoonvolution and curve fitting of health bean leaves and broad bean diseased leaves in the range of 1 700-1 500 cm-1, three sub-peaks were obtained at 1 550 cm-1 (protein amide II band), 1 605 cm-1 (lignin) and 1 650 cm-1 (protein amide l band).The ratios of relative areas of the bands of amide II, lignin, and amide I were 38.86%, 28.68% and 32.47% in the spectra of healthy leaves, respectively, it was distinguished from the diseased leaves (chocolate spot leaf: 15.42%, 42.98% and 41.61%, ring spot leaf:32.39%, 35.63% and 31.98%, rust leaf: 13.97%, 46.40% and 39.65%, yellowing leaf curl disease leaf: 24.01%,36.55% and 39.44%). For sub-peak area ratios (A1 563/A1 605, and A1 563/A1 654). those of four kinds of diseased leaves were smaller than that of healthy leaves, and there were also differences among four kinds of diseased leaves. The results proved that FTIR combining with curve fitting might be a potentially useful tool for detecting different kinds of broad bean diseases. [ABSTRACT FROM AUTHOR]
- Published
- 2015
22. X-ray phase-contrast CT imaging of the acupoints based on synchrotron radiation.
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Chenglin, Liu, Xiaohua, Wang, Hua, Xu, Fang, Liu, Ruishan, Dang, Dongming, Zhang, Xinyi, Zhang, Honglan, Xie, and Tiqiao, Xiao
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ACUPUNCTURE points , *SYNCHROTRON radiation , *COMPUTED tomography , *X-ray imaging , *PHASE-contrast microscopy , *MORPHOLOGY - Abstract
In this paper, the morphology of the acupuncture point (abbreviated as acupoint hereafter) or tissue where there were no acupoints in the fractional rabbit hind limb was studied by in-line phase contrast CT imaging (PCI-CT) methods based on synchrotron radiation. The density of micro-vessels was calculated for tissues with acupoints or without acupoints. Differences between acupoints area and non-acupoint areas determined by the density of the micro-vessels propose a strong evidence of the existence of acupoints. Our results showed that there were two significantly higher densities of the micro-vessels, where two acupoints were located, respectively. In addition, there were large numbers of involutedly microvascular structure in the acupoint areas. Nevertheless, in non-acupoints area, the microvascular structure was relatively simple and flat. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
23. Calculation of combined diffusion coefficients in SF6-Cu mixtures.
- Author
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Linlin Zhong, Xiaohua Wang, Mingzhe Rong, Yi Wu, and Murphy, Anthony B.
- Subjects
- *
DIFFUSION coefficients , *COPPER , *SULFIDES , *METAL vapors , *GAS mixtures , *ELECTRIC fields , *ELECTRIC potential - Abstract
Diffusion coefficients play an important role in the description of the transport of metal vapours in gas mixtures. This paper is devoted to the calculation of four combined diffusion coefficients, namely, the combined ordinary diffusion coefficient, combined electric field diffusion coefficient, combined temperature diffusion coefficient, and combined pressure diffusion coefficient in SF6-Cu mixtures at temperatures up to 30000 K. These four coefficients describe diffusion due to composition gradients, applied electric fields, temperature gradients, and pressure gradients, respectively. The influence of copper fluoride and sulfide species on the diffusion coefficients is shown to be negligible. The effect of copper proportion and gas pressures on these diffusion coefficients is investigated. It is shown that increasing the proportion of copper generally increases the magnitude of the four diffusion coefficients, except for copper mole fractions of 90% or more. It is further found that increasing the pressure reduces the magnitude of the coefficients, except for the combined temperature diffusion coefficient, and shifts the maximum of all four coefficients towards higher temperatures. The results presented in this paper can be applied to the simulation of high-voltage circuit breaker arcs. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
24. Thermal Diffusion Desorption for the Comprehensive Analysis of Organic Compounds.
- Author
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Zhibin Yin, Xiaohua Wang, Weifeng Li, Miaohong He, Wei Hang, and Benli Huang
- Subjects
- *
DIFFUSION , *DESORPTION , *ORGANIC compounds , *SOLVENTS , *IONS - Abstract
Comprehensive analysis of organic compounds is crucial yet challenging considering that information on elements, fragments, and molecules is unavailable simultaneously by current analytical techniques. Additionally, many compounds are insoluble or only dissolve in toxic solvents. A solvent- and matrix-free strategy has been developed which allows the organic compound analyzed in its original form. It utilizes thermal diffusion desorption with the solid analyte irradiated with high energy laser. It is capable of providing explicit elemental, fragmental, and molecular information simultaneously for a variety of organic compounds. Thermal diffusion desorption has many advantages compared to the electrospray and MALDI techniques. The protons that form the protonated molecular ions originate from the analyte itself. All the elements and fragments are also derived from the analyte itself, which provides abundant information and expedites the identification of organic compounds. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
25. Temporal modulation of plasma species in atmospheric dielectric barrier discharges.
- Author
-
Aijun Yang, Xiaohua Wang, Dingxin Liu, Mingzhe Rong, and Kong, Michael G.
- Subjects
- *
PLASMA physics , *ELECTRIC discharges , *ATMOSPHERIC electricity , *IONIC conductivity , *CATIONS - Abstract
The atmospheric pressure dielectric barrier discharge in helium is a pulsed discharge in nature and the moment of maximum species densities is almost consistent with peak discharge current density. In this paper, a one-dimensional fluid model is used to investigate the temporal structure of plasma species in an atmospheric He-N2 dielectric barrier discharge (DBD). It is demonstrated that there exist microsecond delays of the moments of the maximum electron and ion densities from the peak of discharge current density. These time delays are caused by a competition between the electron impact and Penning ionizations, modulated by the N2 level in the plasma-forming gas. Besides, significant electron wall losses lead to the DBD being more positively charged and, with a distinct temporal separation in the peak electron and cation densities, the plasma is characterized with repetitive bursts of net positive charges. The temporal details of ionic and reactive plasma species may provide a new idea for some biological processes. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
26. Laser-induced plasma temperature.
- Author
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Shudi Zhang, Xiaohua Wang, Miaohong He, Yunbin Jiang, Bochao Zhang, Wei Hang, and Benli Huang
- Subjects
- *
LASER plasmas , *PLASMA temperature , *PHYSICAL & theoretical chemistry , *WAVELENGTHS , *PLASMA confinement , *LOCAL thermodynamic equilibrium - Abstract
It is of great importance to explore the evolution of laser-induced plasma (LIP) properties, especially plasma temperature, with regard to variations of experiment conditions in both theoretical study and routine applications. By investigating the influence of various factors on plasma temperature, one can gain knowledge about the processes in plasma and adjust experimental conditions to obtain optimum analytical performance. Herein the fundamental theories and calculation methods of LIP temperature via spectroscopic approaches are briefly reviewed. Its temporal and spatial evolutions together with several influencing factors are discussed, such as laser parameters, ambient surrounding, and physical & chemical properties of the sample. The results summarized exhibit the general trend that LIP temperature increases with increasing laser wavelength, pulse width, laser energy, background gas pressure, and sample hardness. On the other hand, it decreases with time elapsing and distance from sample surface. Moreover, plasma temperature generated in argon surrounding is higher than that in other gas species, and the rank of temperature values generated from different samples exhibits a general tendency of Cu>Fe>Ni≈Al≈glass≈rock. Additionally, LIP temperature tends to increase as lens focal point approaches sample surface, and the plasma confinement effect in sample cavity is significant in altering plasma temperature. Various explanations are given to interpret these temperature behaviors. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
27. Experimental study on Qizhu formula for modulating survivin, an inhibitor of apoptosis, in MGC-803 gastric cancer cells.
- Author
-
HAO WEN, XIAOHUA WANG, and ZHAOWEI SHAN
- Subjects
- *
SURVIVIN (Protein) , *APOPTOSIS , *MESSENGER RNA , *ACTIN research , *PROTEIN research - Abstract
The aim of this study was to investigate the mechanism of action of Qizhu formula, a Chinese medicinal empirical formula, in modulating the action of survivin, an inhibitor of apoptosis, in MGC-803 gastric cancer cells. Western blot analysis and reverse transcription-polymerase chain reaction (RT-PCR) were applied to detect the effect of varying concentrations of Qizhu formula in the modulation of the expression of survivin in MGC-803 human gastric adenocarcinoma cells. The western blot analysis results demonstrated that Qizhu formula exerted no significant effects on the protein expression of the β-actin housekeeping gene, whereas it exerted a significant inhibitory effect on the protein expression of the apoptosis-related survivin gene at concentrations of 250 µg/ml and, particularly, 500 µg/ml. RT-PCR was used to detect the effect of Qizhu formula on survivin mRNA in MGC-803 human gastric adenocarcinoma cells. The ratio of survivin/β-actin in the 0.1% dimethylsulfoxide and the 125, 250 and 500 µg/ml groups of Qizhu formula was 0.4543, 0.4025, 0.2415 and 0.2235, respectively. Therefore, Qizhu formula exerted a distinct inhibitory effect on the mRNA expression of survivin in MGC-803 cells in a dose-dependent manner. In conclusion, Qizhu formula may modulate the apoptosis of MGC-803 human gastric adenocarcinoma cells, which is associated with the downregulation of survivin mRNA and protein expression. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
28. Efficient local representations for three-dimensional palmprint recognition.
- Author
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Bing Yang, Xiaohua Wang, Jinliang Yao, Xin Yang, and Wenhua Zhu
- Subjects
- *
PALMPRINT recognition , *BIOMETRIC identification , *FRACTAL dimensions , *PRINCIPAL components analysis , *CURVATURE - Abstract
Palmprints have been broadly used for personal authentication because they are highly accurate and incur low cost. Most previous works have focused on two-dimensional (2-D) palmprint recognition in the past decade. Unfortunately, 2-D palmprint recognition systems lose the shape information when capturing palmprint images. Moreover, such 2-D palmprint images can be easily forged or affected by noise. Hence, three-dimensional (3-D) palmprint recognition has been regarded as a promising way to further improve the performance of palmprint recognition systems. We have developed a simple, but efficient method for 3-D palmprint recognition by using local features. We first utilize shape index representation to describe the geometry of local regions in 3-D palmprint data. Then, we extract local binary pattern and Gabor wavelet features from the shape index image. The two types of complementary features are finally fused at a score level for further improvements. The experimental results on the Hong Kong Polytechnic 3-D palmprint database, which contains 8000 samples from 400 palms, illustrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
29. Compressive video sensing with limited measurements.
- Author
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Tao Li, Xiaohua Wang, Weihe Wang, and Katsaggelos, Aggelos K.
- Subjects
- *
VIDEO compression , *ALGORITHMS , *SIGNAL-to-noise ratio , *COMPUTATIONAL complexity , *WAVELETS (Mathematics) - Abstract
Compressive sensing (CS) is an innovative technology, allowing us to capture signals with significantly fewer samples than those required by classical Nyquist theory. We propose a novel adaptive video compressive sensing algorithm to exploit the potential of CS in video acquisition. Each frame is divided into blocks to take advantage of its inhomogeneity. We first classify the blocks into one of three types based on their texture complexity and their temporal difference from neighboring frames based on which we determine the number of required measurements. In the reconstruction process, we use the measurements made for the later frames to assist the recovery of previous ones, thus ensuring improved reconstruction quality even when the number of measurements for each frame is limited. Our experimental results demonstrate that we not only obtain significant visual quality improvement but also achieve at least 2.5 dB gain in peak signal-to-noise ratio compared with the existing video compressive sensing algorithms. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
30. Efficient hybrid method for time reversal superresolution imaging.
- Author
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Xiaohua Wang, Wei Gao, and Bingzhong Wang
- Subjects
- *
TIME reversal , *HIGH resolution imaging , *ELECTROMAGNETIC devices , *IMAGE analysis , *ESTIMATION theory - Abstract
An efficient hybrid time reversal (TR) imaging method based on signal subspace and noise subspace is proposed for electromagnetic superresolution detecting and imaging. First, the locations of targets are estimated by the transmitting-mode decomposition of the TR operator (DORT) method employing the signal subspace. Then, the TR multiple signal classification (TR-MUSIC) method employing the noise subspace is used in the estimated target area to get the superresolution imaging of targets. Two examples with homogeneous and inhomogeneous background mediums are considered, respectively. The results show that the proposed hybrid method has advantages in CPU time and memory cost because of the combination of rough and fine imaging. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
31. Cytotoxic and Radical Scavenging Nor-Dammarane Triterpenoids from Viburnum mongolicum.
- Author
-
Xiaohua Wang and Wei Wang
- Subjects
- *
DAMMARANES , *TRITERPENOIDS , *VIBURNUM , *NUCLEAR magnetic resonance spectroscopy , *CANCER cells , *CELL culture - Abstract
The ethanol extract of the whole plants of Viburnum mongolicum afforded six new nor-dammarane triterpenoids: 3β,12β-dihydroxy-25,26,27-trinordammara-22-en -24,20-olide (1), 3β,12β-dihydroxy-24α-methoxy-25,26,27-trinordammara-20,24-epoxy (2), 3β-O-acetyl-12β-hydroxy-23,24,25,26,27-hexanordammarane-20-one (3), 12β-Oacetyl- 15α-hydroxy-17β-methoxy-3-oxo-20,21,22-23,24,25,26,27-octanordammanrane (4), 12β-O-acetyl-15α,17β-dihydroxy-3-oxo-20,21,22-23,24,25,26,27-octanordammanrane (5), and 12β,15α-dihydroxy-3-oxo-17-en-20,21,22-23,24,25,26,27-octanordammanrane (6), together with two known nor-dammarane triterpenoids, 12β-hydroxy-3-oxo-24α-methoxy- 25,26,27-trinordammara-20,24-epoxy (7) and 3β,12β-dihydroxy-23,24,25,26,27- hexanordammarane-20-one (8). The structures of the isolated compounds were established based on 1D and 2D (¹H-¹H COSY, HMQC, and HMBC) NMR spectroscopy, in addition to high resolution mass spectrometry. The isolated compounds were tested in vitro for cytotoxic potential against seven tumor cell lines and radical scavenging activities. Compounds 4-6 exhibited significant cytotoxic activities against all tested tumor cell lines and radical scavenging activities against ABTS+ radicals comparable with the standard drug Trolox. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
32. The chromosome number, karyotype and genome size of the desert plant diploid Reaumuria soongorica (Pall.) Maxim.
- Author
-
Xiaohua Wang, Tao Zhang, Zengnan Wen, Honglang Xiao, Zujun Yang, Guoxiong Chen, and Xin Zhao
- Subjects
- *
DESERT plants , *PLANT chromosomes , *KARYOTYPES , *RECOMBINANT DNA , *PLANT genomes - Abstract
Extreme drought and salt resistant plant Reaumuria soongorica is of great potential for revealing genetic bases unique to naturally stress-tolerant plants. A preliminary genome survey, including chromosome number, karyotype, chromosomal localization of 45S rDNA loci and genome size was conducted with R. soongorica collected from Lanzhou, China. Chromosome counting showed that R. soongorica is diploid with chromosome number of 22. Karyotypical analysis illustrated that the chromosomes size ranges from 3.38 to 5.51 μm, and the chromosomal formula is 2 n = 2 x = 22 = 4 m + 14sm + 4st. Fluorescence in situ hybridization revealed that four pairs of 45SrDNA signals were detected at the end of R. soongorica chromosomes. The flow cytometry analysis indicated that the mean C value of R. soongorica is 0.806 pg with predicted genome size of about 778 Mb. The results indicate that the extreme drought and salt resistance of R. soongorica was not attributed to a big and complicate genome and also offer some clues in resolving the problems of taxonomy and evolution in Tamaricaceae. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
33. Long Memory from Sauerbrey Equation: A Case in Coated Quartz Crystal Microbalance in terms of Ammonia.
- Author
-
Xiaohua Wang, Ming Li, and Shengyong Chen
- Subjects
- *
QUARTZ crystal microbalances , *EQUATIONS , *AMMONIA , *QUARTZ crystals , *ELECTRODES - Abstract
The Sauerbrey equation is a useful empirical model in material science to represent the dynamics of frequency change denoted by Δf in an area, denoted by A, of the electrode in terms of the increment of the mass, which is denoted by Δm, loaded on the surface of the crystal under a certain resonant frequency f0. For the purpose of studying Δf from the point of view of time series, we first propose two types of the modified representations of the Sauerbrey equation by taking time as an argument to represent Δf as a function expressed by x(t, f0, A, Δm), where t is time. Usually, Δf is studied experimentally for the performance evaluation of the tested quartz used in ammonia sensors. Its properties in time series, however, are rarely reported. This paper presents the fractal properties of Δf. We will show that Δf is long range dependent (LRD). Consequently, it is heavy tailed according to the Taqqu's theorem. The Hurst parameter (H) of Δf approaches one, implying its strong long memory, providing a new explanation of the repeatability of the experiments and novel point of view of the dynamics of Δf relating to the Sauerbrey equation in material science. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
34. Mice lacking the matrix metalloproteinase-9 gene reduce renal interstitial fibrosis in obstructive nephropathy.
- Author
-
Xiaohua Wang, Yang Zhou, Ruoyun Tan, Mingxia Xiong, Weichun He, Li Fang, Ping Wen, Lei Jiang, and Junwei Yang
- Abstract
Matrix metalloproteinase- 9 (MMP-9) is one of the major components of the matrix proteolytic network, and its role in the pathogenesis of renal interstitial fibrosis remains largely unknown. Here, we demonstrate that ablation of MMP-9 attenuated renal interstitial fibrotic lesions in obstructive nephropathy. Mice lacking MMP-9 were less likely to develop morphological injury, which was characterized by a reduced disruption of tubular basement membrane (TBM) and expression of fibronectin as well as deposition of total tissue collagen in the kidneys after sustained ureteral obstruction compared with their wild-type counterparts. Deficiency of MMP-9 blocked tubular epithelial-tomyofibroblast transition (EMT) but did not alter the induction of transforming growth factor (TGF)-β1 axis expression in the obstructed kidneys. In vitro, TBM, which was digested by MMP-9 instead of MMP-9 itself, induces EMT and enhances migration of transformed cells. Thus increased MMP-9 is detrimental in renal interstitial fibrogenesis through a cascade of events that leads to TBM destruction and in turn to promotion of EMT. Our findings establish a crucial and definite importance of MMP-9 in the pathogenesis of renal interstitial fibrosis at the whole-animal level. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
35. Thermally Induced Conformation Transition of Triple-Helical Lentinan in NaCl Aqueous Solution.
- Author
-
Xiaohua Wang, Xiaojuan Xu, and Lina Zhang
- Subjects
- *
CHAINS , *HOISTING machinery , *CHAIN drive , *SURVEYORS' chains , *ATOMIC force microscopy - Abstract
Lentinan, a β-(1 → 3)- d-glucan, was isolated from Lentinus edodesby using an improved extraction and purification method to show good water solubility and high yield. The results from 13C NMR, size-exclusion chromatography combined with multiangle laser light scattering (SEC-MALLS), dynamic light scattering (DLS), and optical rotation revealed that lentinan existed in a triple-helical conformation in the aqueous solution at 25 °C, whereas the thermally induced conformation transition from triple helix to single flexible chains occurred at elevated temperatures. The dependences of the weight-average molecular weight ( Mw), radius of gyration (⟨ s2⟩ z1/2), hydrodynamic radius ( Rh), intrinsic viscosity ([η]), and specific optical rotation of lentinan on temperature in 0.9% NaCl aqueous solution showed an abrupt drop at 130−145 °C. It was confirmed that the conformation transitions from triple strand to single chain and from extended chains to winding chains for lentinan were completed rapidly at 130−145 °C, as a result of the simultaneous destruction of the intra- and intermolecular hydrogen bonds in lentinan. The thermally induced conformational transition was irreversible. The results from atomic force microscopy (AFM) and DLS demonstrated the existence of intrachain entanglement for the triple-helical chains, leading to the wormlike linear, circular, and crossover species for lentinan having high Mw(1.71 × 10 6) in aqueous solution at 25 °C. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
36. Chunk Segmentation of Chinese Sentences Using a Combined Statistical and Rule-based Approach (CSRA).
- Author
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Rongbo Wang, Xiaohua Wang, Zhiqun Chen, and Zheru Chi
- Subjects
- *
SENTENCES (Grammar) , *CHINESE language , *ALGORITHMS , *STATISTICS - Abstract
Deep parsing of Chinese sentences is a very challenging task due to their complexity such as ambiguous word boundaries and meanings. An alternative mode of Chinese language processing is to perform shallow parsing of Chinese sentences in which chunk segmentation plays an important role. In this paper, we present a chunk segmentation algorithm using a combined statistical and rule-based approach (CSRA). The decision rules for refining chunk segmentation are generated from incorrectly segmented chunks from a statistical model which is built on a training corpus. Experimental results show that the CSRA works well and produces satisfactory chunk segmentation results for subsequent processes such as chunk tagging and chunk collocation extraction. [ABSTRACT FROM AUTHOR]
- Published
- 2007
37. The influence of using biogas digesters on family energy consumption and its economic benefit in rural areas—comparative study between Lianshui and Guichi in China
- Author
-
Xiaohua, Wang, Chonglan, Di, Xiaoyan, Hu, Weiming, Wu, Xiaoping, Jiang, and Shangyun, Jiang
- Subjects
- *
POWER resources , *ENERGY shortages , *ENERGY consumption , *ENERGY policy - Abstract
Abstract: The construction of biogas digesters has improved the family energy consumption structure, promoted the development of livestock breeding and farm production in the countryside. Through the comparative study of the questionnaires filled out by individual families in Lianshui, Jiangsu Province and Guichi, Anhui Province, we figured out the different effects of biogas digesters in different areas on household energy consumption and their benefits to economy and environment. [Copyright &y& Elsevier]
- Published
- 2007
- Full Text
- View/download PDF
38. Imaging of Dynamic Secretory Vesicles in Living Pollen Tubes of Picea meyeri Using Evanescent Wave Microscopy.
- Author
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Xiaohua Wang, Yan Teng, Qinli Wang, Xiaojuan Li, Xianyong Sheng, Maozhong Zheng, Jozef Samaj, Baluška, František, and Jinxing Lin
- Subjects
- *
POLLINATION , *CELL membranes , *MICROTUBULES , *FLUORESCENCE , *POLLEN tube , *PALYNOLOGY - Abstract
Evanescent wave excitation was used to visualize individual, FM4-64-1abeled secretory vesicles in an optical slice proximal to the plasma membrane of Picea meyeri pollen tubes. A standard upright microscope was modified to accommodate the optics used to direct a laser beam at a variable angle. Under evanescent wave microscopy or total internal reflection fluorescence microscopy, fluorophores localized near the surface were excited with evanescent waves, which decay exponentially with distance from the interface. Evanescent waves with penetration depths of 60 to 400 nm were generated by varying the angle of incidence of the laser beam. Kinetic analysis of vesicle trafficking was made through an approximately 300-nm optical section beneath the plasma membrane using time-lapse evanescent wave imaging of individual fluorescently labeled vesicles. Two-dimensional trajectories of individual vesicles were obtained from the resulting time-resolved image stacks and were used to characterize the vesicles in terms of their average fluorescence and mobility, expressed here as the two-dimensional diffusion coefficient D². The velocity and direction of vesicle motions, frame-to-frame displacement, and vesicle trajectories were also calculated. Analysis of individual vesicles revealed for the first time, to our knowledge, that two types of motion are present, and that vesicles in living pollen tubes exhibit complicated behaviors and oscillations that differ from the simple Brownian motion reported in previous investigations. Furthermore, disruption of the actin cytoskeleton had a much more pronounced effect on vesicle mobility than did disruption of the microtubules, suggesting that actin cytoskeleton plays a primary role in vesicle mobility. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
39. Oncolytic Adenovirus-Mediated E1A Gene Therapy Induces Tumor-Cell Apoptosis and Reduces Tumor Angiogenesis Leading to Inhibition of Hepatocellular Carcinoma Growth in Animal Model.
- Author
-
Zhenmin Ye, Xiaohua Wang, Siguo Hao, Jiang Zhong, Jim Xiang, and Jicheng Yang
- Subjects
- *
CANCER treatment , *NEOVASCULARIZATION , *GENE therapy , *GENETIC engineering - Abstract
Oncolytic adenovirus (rAd)-mediated E1A gene therapy of cancer has become a novel therapeutic modality.In this study, we constructed a recombinant oncolytic adenovirus (rAd-E1A) expressing the tumorsuppressor E1A gene. We demonstrated that the rAd-E1A replicated in HepG2 and SMMC-7721 humanhepatocellular carcinoma (HCC) cells but attenuated in the normal liver cell line HL-7702. It inducedHCC cell apoptosis through upregulation of apoptosis-associated Bax, caspase-3, and Fas and downregulationof survivin and Bcl-2 in a p53-dependent pathway. It also downregulated the expression of angiogenesis-associated vascular endothelial growth factor (VEGF) and CD34 genes and reduced tumorvessel formation and angiogenesis. In mice bearing SMMC-7721 tumors, intratumoral injections of rAd-E1A significantly inhibited HCC growth. Therefore, the oncolytic adenovirus-mediated E1A gene therapymay be a useful therapeutic approach for HCC treatment. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
40. Development and Application of an Anisotropic Two-Equation Model for Flows With Swirl and Curvature.
- Author
-
Xiaohua Wang and Thangam, Siva
- Subjects
- *
TURBULENCE , *FLUID dynamics , *SCALING laws (Statistical physics) , *STATISTICAL physics , *CURVATURE - Abstract
An anisotropic two-equation model is developed through a novel technique that involves the representation of the energy spectrum and invariance based scaling. In this approach the effect of rotation is used to modify the energy spectrum, while the influence of swirl is modeled based on scaling laws. The resulting generalized two-equation turbulence model is validated for several benchmark turbulent flows with swirl and curvature. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
41. Analysis and simulation on rural energy–economy system on Shouyang County in China
- Author
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Xiaohua, Wang, Yunrong, Hu, Xiaqing, Dia, and Yuedong, Zhoa
- Subjects
- *
RENEWABLE energy sources , *SYSTEMS engineering , *INDUSTRIAL engineering , *POWER resources - Abstract
Abstract: A basic feedback structure of rural energy–economy system is approached in this paper based on systems engineering and system dynamics (SD) principles. The dynamics simulation model in then developed and applied in analyzing the energy construction of Shouyang County, Jiangsu Province in China. Consequently, some related policies and measures are proposed. [Copyright &y& Elsevier]
- Published
- 2006
- Full Text
- View/download PDF
42. Hypoxia-induced reactive oxygen species downregulate ETB receptor- mediated contraction of rat pulmonary arteries.
- Author
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Xiaohua Wang, Mel Tong, Shashi Chinta, J. Usha Raj, and Yuansheng Gao
- Subjects
- *
HYPOXEMIA , *PULMONARY artery , *PULMONARY blood vessels , *ENDOTHELINS , *VASOCONSTRICTORS , *VASCULAR endothelium , *CATALASE , *HEMOPROTEINS , *POLYETHYLENE glycol - Abstract
Production of reactive oxygen species (ROS) may be increased during hypoxia in pulmonary arteries. In this study, the role of ROS in the effect of hypoxia on endothelin (ET) type B (ETB) receptor-mediated vasocontraction in lungs was determined. In rat intrapulmonary (∼0.63 mm ID) arteries, contraction induced by IRL-1620 (a selective ETB receptor agonist) was significantly attenuated after 4 h of hypoxia (30 mmHg Po2) compared with normoxic control (140 mmHg Po2). The effect was abolished by tiron, a scavenger of superoxide anions, but not by polyethylene glycol (PEG)-conjugated catalase, which scavenges H2O2. The hypoxic effect on ETB receptor-mediated vasoconstriction was also abolished by endothelium denudation but not by nitro-L-arginine and indomethacin. Exposure for 4 h to exogenous superoxide anions, but not H2O2, attenuated the vasoconstriction induced by IRL-1620. Confocal study showed that hypoxia increased ROS production in pulmonary arteries that were scavenged by PEG-conjugated SOD. In endothelium-intact pulmonary arteries, the ETB receptor protein was reduced after 4 h of exposure to hypoxia, exogenous superoxide anions, or ET-1. BQ-788, a selective ETB receptor antagonist, prevented these effects. ET-1 production was stimulated in endothelium-intact arteries after 4 h of exposure to hypoxia or exogenous superoxide anions. This effect was blunted by PEG-conjugated SOD. These results demonstrate that exposure to hypoxia attenuates ETB receptor-mediated contraction of rat pulmonary arteries. A hypoxia-induced production of superoxide anions may increase ET-1 release from the endothelium and result in down-regulation of ETB receptors on smooth muscle. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
43. Mechanical Condition Recognition of Medium- Voltage Vacuum Circuit Breaker Based on Mechanism Dynamic Features Simulation and ANN.
- Author
-
Mingzhe Rong, Xiaohua Wang, Wu Yang, and Shenli Jia
- Subjects
- *
VACUUM circuit breakers , *ALGORITHMS , *NEURAL circuitry , *VACUUM , *SIMULATION methods & models , *VACUUM switches - Abstract
A new research method is proposed for the medium-voltage (MV) vacuum circuit breaker's (CB's) mechanical condition monitoring, which combines the mechanism dynamic features simulation and mechanical condition recognition algorithm bised on artificial neural networks (ANNs). This method includes three steps: First, the relations between eigen- values and mechanical failures of a vacuum circuit breaker (CB) through simulation instead of measurement are obtained. In this paper, the mechanism dynamic features of a vacuum CB in failure are simulated; the simulation results indicate that the parameter that can be monitored-main angle-has different characters for different mechanism failures. Second, the eigenvalues for different failure conditions are described by three parameters. Third, mechanical condition recognition of the MV vacuum CB by an algorithm based on ANN is realized. It is concluded by the work mentioned above, both the known mechanical condition type and the new mechanical condition type of the medium-voltage vacuum CB can be recognized with predetermined reliability. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
44. Influence of using household biogas digesters on household energy consumption in rural areas—a case study in Lianshui County in China
- Author
-
Xiaohua, Wang and Jingfei, Li
- Subjects
- *
INDUSTRIAL wastes , *BIOGAS , *SURVEYS , *FAMILIES - Abstract
Development of household biogas digesters in rural areas and integrated use of agricultural wastes has changed the structure of rural household energy consumption and greatly increased the application of highly efficient organic fertilizer, improved soil fertility and promoted sustainable agricultural development. This paper mainly discusses the influence of using household biogas digesters on household energy consumption in rural areas based on the data from the survey of rural household energy consumption and household biogas digesters in Lianshui County. The results showed that the construction of biogas digesters leads to the obvious decrease of per capita energy consumption in rural families and biogas mainly takes the place of some stalk and straw and a few firewood but does not substitute other forms of energy, especially commercial energy. [Copyright &y& Elsevier]
- Published
- 2005
- Full Text
- View/download PDF
45. Study on affecting factors and standard of rural household energy consumption in China
- Author
-
Xiaohua, Wang and Zhenmin, Feng
- Subjects
- *
ENERGY consumption , *HOUSEHOLDS , *INCOME - Abstract
In order to understand the basic character and development tendency of China’s rural household energy consumption, we present the total rural household energy consumption of 1998 in China, which was 340.97 million tce (tons of standard coal equivalent,
1 tce=7×106 kcal ), according to statistics gathered from 30 provinces and 40.14% of which was commercial energy. This paper shows the correlation coefficients of the data, such as per-capita energy consumption of standard coal equivalent (PCEC), effective heat consumption for livelihood per capita per day (EHC), the proportion of commercial energy in EHC (PCE), annual electricity consumption for livelihood per capita (AEC) and so on. The paper suggests using EHC, PCE and AEC as the character indices to further reveal the correlation of per-capita income (PCI) and average annual temperature (AAT). [Copyright &y& Elsevier]- Published
- 2005
- Full Text
- View/download PDF
46. Simulation and Analysis of Rigid/Foil Electrolytic In-Process Dressing (ELID) Systems for Grinding.
- Author
-
Zhenqi Zhu, Xiaohua Wang, Thangam, Siva, and Rajurkar, K.
- Subjects
- *
ELECTROCHEMICAL analysis , *SIMULATION methods & models , *ELECTROLYTES , *HIGH-speed machining , *GRINDING machines - Abstract
The fluid flow problem in a traditional electrolytic in-process dressing (ELID) system is analyzed and solved numerically. The predicted mean velocity profiles in the dressing zone show flow patterns that are in good agreement with the mean velocity distributions for plane laminar/turbulent Couette flows observed in the experiments. The computational results reveal that insufficient electrolyte supply rate is the cause of the failure of the traditional ELID system for high-speed grinding. Results also show that to obtain effec- tive high-speed ELID grinding, a consistent high inlet electrolyte velocity or supply rate is required. For the foil EL1D system, governing equations describing the fluid flow in the dressing zone and the foil elastic deformation are formulated. Analytical solution based on unidirectional flow model for the problem is presented and effects of wheel surface speed and foil tension on the performance of the dressing system are discussed. It is shown that the foil EL1D system has the potential to be effective for high-speed grinding with low electrolyte supply rates. The results will be useful to the development of new machine systems and processes for high-speed grinding. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
47. 2D full-wave finite-difference frequency-domain method for lossy metal waveguide.
- Author
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Bing-Zhong Wang, Xiaohua Wang, and Wei Shao
- Subjects
- *
WAVEGUIDES , *FINITE differences , *ELECTRIC waves , *ELECTROMAGNETIC waves , *ELECTRIC fields - Abstract
The 2D finite-difference frequency-domain method combined with the surface-impedance boundary condition is applied for the analysis of dispersion characteristics of lossy metal waveguides. Six electromagnetic field components are involved in the final eigen equation. By solving the eigen equation, the method finds the propagation constants for a given frequency. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 158–161, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20238 [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
48. Biofuel use and its emission of noxious gases in rural China
- Author
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Xiaohua, Wang and Zhenmin, Feng
- Subjects
- *
BIOMASS , *ENERGY development , *FUELWOOD - Abstract
This article discusses biomass resources and its consumption in China’s farming area. In 2000, the annual yield of crop-straw was about 6900 Mt, of which 54% could be used as a source of energy. The reasonable supply of firewood was about 150 Mt. The total consumption of biofuel in China’s rural area was 219 Mtce, among which crop-straw and firewood accounted for 44 and 56%, respectively. The proportion of the available heat from commercial energy over the total available heat consumed in the countryside was 0.513, and biofuel consumption decreases 3.8% annually. China is at a transition point from a period of non-commercial energy to a period of commercial energy being the main source of energy. This article discusses the effect of the discharge of noxious gases caused by the consumption of biofuel. [Copyright &y& Elsevier]
- Published
- 2004
- Full Text
- View/download PDF
49. Common factors and major characteristics of household energy consumption in comparatively well-off rural China
- Author
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Xiaohua, Wang and Zhenmin, Feng
- Subjects
- *
ENERGY conservation , *ENERGY consumption , *FUEL - Abstract
Common factors that influence Chinese rural household energy consumption are proposed and major demand characteristics of well-off rural areas are analyzed on the basis of survey data. A system of major characteristic indicators for rural household energy consumption includes effective heat consumption for livelihood per capita per day (EHC), the proportion of commercial energy in EHC (PCE) and annual electricity consumption for livelihood per capita (AEC). Typical values in three economic regions (out-of-poverty, well-off and rich areas) of China are also given. [Copyright &y& Elsevier]
- Published
- 2003
- Full Text
- View/download PDF
50. Sustainable development of rural energy and its appraising system in China
- Author
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Xiaohua, Wang and Zhenmin, Feng
- Subjects
- *
BIOMASS , *RENEWABLE energy sources , *SUSTAINABLE development - Abstract
The local biomass resources have been used in rural China for quite a long time, which has a close connection with and will inevitably affect the environment. In recent years, China has experienced rapid economic growth and equally rapid increases in energy use, especially commercial energy, in rural areas. As a result, energy induced environmental degradation has also increased in rural China. This paper discusses the relationship between China’s rural energy and its sustainable development. It brings forward the index system for appraising the sustainable development of rural energy (SDRE), calculates the weighing of each index with analytic hierarchy process (AHP), puts forward the quantification method and provides the basis for the research of the rural energy for sustainable development in different areas and periods. [Copyright &y& Elsevier]
- Published
- 2002
- Full Text
- View/download PDF
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