92 research outputs found

    Finite-time Anti-synchronization of Memristive Stochastic BAM Neural Networks with Probabilistic Time-varying Delays

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    This paper investigates the drive-response finite-time anti-synchronization for memristive bidirectional associative memory neural networks (MBAMNNs). Firstly, a class of MBAMNNs with mixed probabilistic time-varying delays and stochastic perturbations is first formulated and analyzed in this paper. Secondly, an nonlinear control law is constructed and utilized to guarantee drive-response finite-time anti-synchronization of the neural networks. Thirdly, by employing some inequality technique and constructing an appropriate Lyapunov function, some anti-synchronization criteria are derived. Finally, a number simulation is provided to demonstrate the effectiveness of the proposed mechanism

    A Biodegradable Polyethylenimine-Based Vector Modified by Trifunctional Peptide R18 for Enhancing Gene Transfection Efficiency In Vivo

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    Lack of capacity to cross the nucleus membrane seems to be one of the main reasons for the lower transfection efficiency of gene vectors observed in vivo study than in vitro. To solve this problem, a new non-viral gene vector was designed. First, a degradable polyethylenimine (PEI) derivate was synthesized by crosslinking low-molecular-weight (LMW) PEI with N-octyl-N-quaternary chitosan (OTMCS), and then adopting a designed trifunctional peptide (RGDC- TAT-NLS) with good tumor targeting, cell uptake and nucleus transport capabilities to modify OTMCS-PEI. The new gene vector was termed as OTMCS- PEI-R18 and characterized in terms of its chemical structure and biophysical parameters. Gene transfection efficiency and nucleus transport mechanism of this vector were also evaluated. The polymer showed controlled degradation and remarkable buffer capabilities with the particle size around 100–300 nm and the zeta potential ranged from 5 mV to 40 mV. Agraose gel electrophoresis showed that OTMCS-PEI-R18 could effectively condensed plasmid DNA at a ratio of 1.0. Besides, the polymer was stable in the presence of sodium heparin and could resist digestion by DNase I at a concentration of 63U DNase I/DNA. OTMCS-PEI-R18 also showed much lower cytotoxicity and better transfection rates compared to polymers OTMCS-PEI-R13, OTMCS-PEI and PEI 25 KDa in vitro and in vivo. Furthermore, OTMCS-PEI-R18/DNA complexes could accumulate in the nucleus well soon and not rely on mitosis absolutely due to the newly incorporated ligand peptide NLS with the specific nuclear delivery pathway indicating that the gene delivery system OTMCS-PEI-R18 could reinforce gene transfection efficiency in vivo

    Weight self-misperception and Obesity-related Knowledge, Attitudes, Lifestyle Behaviors and Cardio-metabolic Markers among Chinese School-aged Children and Adolescents

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    Abstract Objective: The relationships between childhood weight self-misperception and obesity-related factors particularly health markers have not been extensively discussed. This study aims to examine the associations between weight self-misperception and obesity-related knowledge, attitudes, lifestyles and cardio-metabolic markers among Chinese pediatric population. Design: Cross-sectional study. Setting: Data sourced from a national survey in Chinese seven provinces in 2013. Participants: Children and adolescents aged 5-19 years. Results: Of the total 14079 participants, there were 14.5% and 2.2% participants over-estimated and under-perceived their weight, respectively. Multi-variable logistic regression was applied to calculate odds ratio (OR) and 95% confidence interval (95% Cl) of obesity-related behaviors and cardio-metabolic markers by actual and perceived weight status. Individuals who perceived themselves as overweight/obese were more likely to have prolonged screen time, insufficient dairy intake, and over sugar-sweetened beverages consumption (all P<0.05), regardless of their weight. Furthermore, actual overweight/obese individuals had higher odds of abnormal cardio-metabolic markers, but a smaller magnitude of association was found among weight under-estimators. Among non-overweight/obese individuals, weight over-estimation was positively associated with abdominal obesity (OR: 10.49, 95% CI: 7.45, 14.76), elevated blood pressure (OR: 1.30, 95% CI: 1.12, 1.51), and dyslipidemia (OR: 1.43, 95% CI: 1.29, 1.58). Conclusions: Weight over-perception was more prevalent than under-estimation, particularly in girls. Weight over-estimators tended to master better knowledge but behave more unhealthily, both weight over-perception and actual overweight/obesity status were associated with poorer cardio-metabolic markers. Future obesity intervention programs should additionally pay attention to the population with inaccurate estimation of weight who were easily overlooked

    Special Issue on “Machine-Learning-Assisted Intelligent Processing and Optimization of Complex Systems”

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    Complex systems and their various characteristics have been widely considered in economic and industrial systems [...

    Analysis of Compound-specific Carbon Isotopic Composition of Polycyclic Aromatic Hydrocarbons by PTV-GC-IRMS

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    BACKGROUND: The carbon isotope ratio of PAHs is stable in the migration and transformation, which is an important traceability index and can be analyzed by gas chromatography-isotope ratio mass spectrometry (GC-IRMS). For samples with low PAH content, meeting the detection limit of GC-IRMS is the premise for high-precision and accurate analysis of the carbon isotope ratio.OBJECTIVES: To establish a PTV injection method with stronger intensity of PAHs,thereby improving the sensitivity of GC-IRMS carbon isotope analysis.METHODS: Parameters of the programmed temperature vaporization (PTV) injector were optimized, including injection mode (constant temperature splitless, PTV splitless and solvent split), pressure process, sample transfer temperature and time, evaporation temperature and time, and splitless time.RESULTS: The optimized parameters were PTV splitless, transfer temperature of 320℃, transfer time of 1.0min, injection pressure operating in a gradient of 40-60-70psi, evaporation temperature of 55℃, evaporation time of 2.5min, and splitless time of 1.5min. Pre-columns reduced the peak width and increased the peak intensity, especially high boiling point PAHs as benzo(a) pyrene, indeno(1,2,3-cd) pyrene, dibenzo(a,h) anthracene and benzo(g,h,i) perylene increased by 50%-100%. The precision of δ13C of 16 PAHs determined by the optimized PTV-GC-IRMS were within 0.5‰. The fractionation within the system can be corrected by two PAH references.CONCLUSIONS:The optimized PTV-GC-IRMS can adjust the precision and accuracy of compound-specific carbon isotope analysis of PAHs at low concentrations, and expand the applicability of isotope tracing in environmental studies

    A Thermal Effect Model for the Impact of Vertical Groundwater Migration on Temperature Distribution of Layered Rock Mass and Its Application

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    On the basis of the one-dimensional heat conduction–convection equation, a thermal effect model for vertical groundwater migration in the stratified rock mass was established, the equations for temperature distribution in layered strata were deduced, and the impacts of the vertical seepage velocity of groundwater and the thermal conductivity of surrounding rocks on the temperature field distribution in layered strata were analyzed. The proposed model was employed to identify the thermal convection and conduction regions at two temperature-measuring boreholes in coal mines, and the vertical migration velocity of groundwater was obtained through reverse calculation. The results show that the vertical temperature distribution of the layered rock mass is subject to the migration of the geothermal water; the temperature curve of the layered formation is convex when the geothermal water travels upward, but concave when the water moves downward. The temperature distribution in the stratified rock mass is also subject to the thermal conductivity of the rock mass; greater thermal conductivity of the rock mass leads to a larger temperature difference among regions of the rock mass, while weaker thermal conductivity results in a smaller temperature difference. A greater velocity of the vertical migration of geothermal water within the surrounding rock leads to a larger curvature of the temperature curve. The model was applied to a study case, which showed that the model could appropriately describe the variation pattern of the ground temperature in the stratified rock mass, and a comparison between the modeling result and the measured ground temperature distribution revealed a high goodness of fit of the model with the actual situation

    4,4&amp;#8242;,6,6&amp;#8242;-Tetra-tert-butyl-2,2&amp;#8242;-[1,3-diazinane-1,3-diylbis(methylene)]diphenol 0.25-hydrate

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    The title compound, C34H54N2O2&amp;#183;0.25H2O, the organic molecule, a potential tetradentate ligand with a bulky phenolic donor, has overall mirror symmetry. A partially occupied water molecule of solvation is present in the lattice. The six-membered 1,3-diazinane ring displays a chair conformation. An intramolecular O&amp;#8212;H...N hydrogen bond ocurs. In the crystal, molecules are linked by O&amp;#8212;H...O interactions

    Finite-time Anti-synchronization of Memristive Stochastic BAM Neural Networks with Probabilistic Time-varying Delays

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    This paper investigates the drive-response finite-time anti-synchronization for memristive bidirectional associative memory neural networks (MBAMNNs). Firstly, a class of MBAMNNs with mixed probabilistic time-varying delays and stochastic perturbations is first formulated and analyzed in this paper. Secondly, an nonlinear control law is constructed and utilized to guarantee drive-response finite-time anti-synchronization of the neural networks. Thirdly, by employing some inequality technique and constructing an appropriate Lyapunov function, some anti-synchronization criteria are derived. Finally, a number simulation is provided to demonstrate the effectiveness of the proposed mechanism

    Exponential Antisynchronization Control of Stochastic Memristive Neural Networks with Mixed Time-Varying Delays Based on Novel Delay-Dependent or Delay-Independent Adaptive Controller

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    The global exponential antisynchronization in mean square of memristive neural networks with stochastic perturbation and mixed time-varying delays is studied in this paper. Then, two kinds of novel delay-dependent and delay-independent adaptive controllers are designed. With the ability of adapting to environment changes, the proposed controllers can modify their behaviors to achieve the best performance. In particular, on the basis of the differential inclusions theory, inequality theory, and stochastic analysis techniques, several sufficient conditions are obtained to guarantee the exponential antisynchronization between the drive system and response system. Furthermore, two numerical simulation examples are provided to the validity of the derived criteria
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