37 research outputs found
Image De-noising on Strip Steel Surface Defect Using Improved Compressive Sensing Algorithm
De-noising for the strip steel surface defect image is conductive to the accurate detection of the strip steel surface defects. In order to filter the Gaussian noise and salt and pepper noise of strip steel surface defect images, an improved compressive sensing algorithm was applied to defect image de-noising in this paper. First, the improved Regularized Orthogonal Matching Pursuit algorithm was described. Then, three typical surface defects (scratch, scar, surface upwarping) images were selected as the experimental samples. Last, detailed experimental tests were carried out to the strip steel surface defect image de-noising. Through comparison and analysis of the test results, the Peak Signal to Noise Ratio value of the proposed algorithm is higher compared with other traditional de-noising algorithm, and the running time of the proposed algorithm is only26.6\% of that of traditional Orthogonal Matching Pursuit algorithms. Therefore, it has better de-noising effect and can meet the requirements of real-time image processing
HBV infection-induced liver cirrhosis development in dual-humanized mice with human bone mesenchymal stem cell transplantation
疾病动物模型是现代医学发展的基石,尤其是重大、突发传染病暴发时,适宜的疾病动物模型可为及时发现病原体、制定防控策略提供强大保障,原创的疾病动物模型已成为衡量一个国家生物医药科研水平的标志。我校夏宁邵教授团队和浙江大学附属第一医院李君教授团队历经5年的协同攻关,终于建立了国际上首个高度模拟人类乙肝病毒(HBV)自然感染诱发的慢乙肝肝硬化小鼠模型。厦门大学公共卫生学院袁伦志博士生、浙江大学医学院附属第一医院江静博士和厦门大学公共卫生学院刘旋博士生为该论文共同第一作者。厦门大学夏宁邵教授、浙江大学附属第一医院李君教授和厦门大学程通副教授为该论文共同通讯作者。【Abstract】Objective: Developing a small animal model that accurately delineates the natural history of hepatitis B virus (HBV) infection and immunopathophysiology is necessary to clarify the mechanisms of host-virus interactions and to identify intervention strategies for HBV-related liver diseases. This study aimed to develop an HBV-induced chronic hepatitis and cirrhosis mouse model through transplantation of human bone marrow mesenchymal stem cells (hBMSCs). Design: Transplantation of hBMSCs into Fah -/- Rag2 -/- IL-2Rγc -/- SCID (FRGS) mice with fulminant hepatic failure (FHF) induced by hamster-anti-mouse CD95 antibody JO2 generated a liver and immune cell dual-humanized (hBMSC-FRGS) mouse. The generated hBMSC-FRGS mice were subjected to assessments of sustained viremia, specific immune and inflammatory responses and liver pathophysiological injury to characterize the progression of chronic hepatitis and cirrhosis after HBV infection. Results: The implantation of hBMSCs rescued FHF mice, as demonstrated by robust proliferation and transdifferentiation of functional human hepatocytes and multiple immune cell lineages, including B cells, T cells, NK cells, dendritic cells (DCs) and immune cell lineages, including B cells, T cells, NK cells, dendritic cells (DCs) and viremia and specific immune and inflammatory responses and showed progression to chronic hepatitis and liver cirrhosis at a frequency of 55% after 54 weeks. Conclusion: This new humanized mouse model recapitulates the liver cirrhosis induced by human HBV infection, thus providing research opportunities for understanding viral immune pathophysiology and testing antiviral therapies in vivo.this work was supported by the national Science and technology Major Project (grant nos. 2017ZX10304402, 2017ZX10203201 and 2018ZX09711003-005-003), the national natural Science Foundation of china(grant nos. 81672023, 81571818 and 81771996), the Scientific research Foundation of the State Key laboratory of Molecular Vaccinology and Molecular Diagnostics (grant no 2016ZY005), Zhejiang Province and State's Key Project of the research and Development Plan of china (grant nos 2017c01026 and 2016YFc1101304/3).该研究获得了传染病防治国家科技重大专项、新药创制国家科技重大专项和国家自然科学基金的资助
Finite-Time Boundedness Control for Nonlinear Networked Systems with Randomly Occurring Multi-Distributed Delays and Missing Measurements
This paper investigates the stochastic finite-time H∞ boundedness problem for nonlinear discrete time networked systems with randomly occurring multi-distributed delays and missing measurements. The randomly occurring multi-distributed delays and missing measurements are described as Bernoulli distributed white noise sequence. The goal of this paper is to design a full-order output-feedback controller to guarantee that the corresponding closed-loop system is stochastic finite-time H∞ bounded and with desired H∞ performance. By constructing a new Lyapunov-Krasovskii functional, sufficient conditions for the existence of output-feedback are established. The desired full-order output-feedback controller is designed in terms of the solution to linear matrix inequalities (LMIs). Finally, a numerical example is provided to show the validity of the designed method
Finite-Time Boundedness Control for Nonlinear Networked Systems with Randomly Occurring Multi-Distributed Delays and Missing Measurements
Finite-Time Nonfragile Dissipative Control for Discrete-Time Neural Networks with Markovian Jumps and Mixed Time-Delays
Ultrasensitive determination of selenium by atomic fluorescence spectrometry using nano-TiO2 pre-concentration and in situ hydride generation
An ultrasensitive, simple and interference-free method using nano-TiO2 preconcentration and in situ slurry hydride generation (HG) coupled with atomic fluorescence spectrometry (AFS) was developed for the determination of trace selenium. Total Se reduced in Se(IV) form can be selectively adsorbed on TiO2 at pH < 8 for pre-concentration, and then separated and slurried/released by a mixture containing 3% (m/v) KBH4 and 1% (m/v) KOH. The slurry solution was mixed with 25% (v/v) HCl to generate selenium hydrides, which was subsequently separated from the liquid phase for subsequent AFS detection. Optimum conditions for adsorption, disadsorption and hydride generation of selenium as well as potential interferences from concomitant ions were investigated. Due to the repulsive force between the positively charged TiO2 and metal cationic ions, this approach permits 1000 mg L 12\ub9 for Fe\ub3+, Ni\ub2+ and Co\ub2+, 500 mg L 12\ub9 for Cu\ub2+ or 100 mg L 12\ub9 for Ag+ and Au\ub3+ present in a 5 \u3bcg L 12\ub9 Se(IV) solution without any significant interferences. A limit of detection of 0.0006 \u3bcg L 12\ub9 was obtained by sampling a 40 mL sample solution. Compared to the conventional HG method, the sensitivity and the limit of detection were improved 17- and 16-fold by the present method, respectively. The proposed method was successfully applied for the determination of trace selenium in several real samples.Peer reviewed: YesNRC publication: Ye
Crystal Structure Analysis and Characterization of NADP-Dependent Glutamate Dehydrogenase with Alcohols Activity from <i>Geotrichum candidum</i>
To better understand its mechanism of activity towards higher alcohols, we overexpressed and purified new Geotrichum candidum GDH (GcGDH). The purified GcGDH (50.27 kDa) was then crystallized, and the crystal diffracted to a resolution of 2.3 Å using X-ray diffraction. We found that the GcGDH crystal structure belonged to space group P212121 and was comprised of two hexamers organized into an asymmetric unit, with each subunit consisting of 452 amino acid residues. The binding sites between higher alcohols or L-glutamic acid and GcGDH were consistent. The optimal reaction conditions for GcGDH and hexanol were a pH of 4.0 and temperature of 30 °C, and those for GcGDH and monosodium glutamate (MSG) were a pH of 8.0 and temperature of 20 °C. The Km values for hexanol and MSG were found to be 74.78 mM and 0.018 mM, respectively. Mutating GcGDH Lys 113 to either Ala or Gly caused a dramatic reduction in its catalytic efficiency towards both MSG and hexanol, suggesting that Lys 113 is essential to the active site of GcGDH
Association between the presence of autoantibodies against adrenoreceptors and severe pre-eclampsia: a pilot study.
BACKGROUND: Pre-eclampsia is the leading cause of maternal and neonatal morbidity and mortality with incompletely understood etiopathogenesis. The purpose of the current study is to determine whether there is a relationship between the presence of autoantibodies against β1, β2 and α1 adrenoreceptors and severe pre-eclampsia. METHODOLOGY/PRINCIPAL FINDINGS: Synthetic peptides corresponding to amino acid sequences of the second extracellular loops of β1, β2 and α1 adrenoreceptors were synthesized as antigens to test 34 patients with severe pre-eclampsia, 36 normal pregnancy women and 40 non-pregnant controls for the presence of autoantibodies using enzyme-linked immunosorbent assay. The respective frequencies of autoantibodies against β1, β2 and α1 adrenoreceptors were 50.0% (17/34), 52.9% (18/34) and 55.9% (19/34) in patients with severe pre-eclampsia, 19.4% (7/36) (p = 0.011), 19.4% (7/36) (p = 0.006) and 17.6% (6/36) (p = 0.001) in normal pregnancy women and 10% (4/40), 7.5% (3/40) and 10% (4/40) (p<0.001) in non-pregnant controls. Titers of these autoantibodies were also significantly increased in patients with severe pre-eclampsia. By logistic regression analysis, the presence of these three autoantibodies significantly increased the risk of neonatal death (odds ratio, 13.5; 95% confidence interval, 1.3-141.3; p = 0.030) and long-term neonatal hospitalization (odds ratio, 5.0; 95% confidence interval, 1.3-19.1; p = 0.018). The risk of hypertension and fetal distress were also associated with the presence of these three autoantibodies. CONCLUSIONS/SIGNIFICANCE: This novel pilot study demonstrated for the first time that the presence of autoantibodies against β1, β2 and α1 adrenoreceptors are increased in patients with severe pre-eclampsia. Pregnant women who are positive for the three autoantibodies are at increased risks of neonatal mortality and morbidity. We posit that these autoantibodies may be involved in the pathogenesis of severe pre-eclampsia