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31.
Both viable and non-viable orally administered Lacticaseibacillus rhamnosus CRL1505 modulate immunity in local (intestine) and distal (respiratory) mucosal sites. So, intestinal adhesion and colonization are not necessary for this probiotic strain to exert its immunomodulatory effects. In this work, a mucus-binding factor knockout CRL1505 strain (ΔmbfCRL1505) was obtained and the lack of binding ability to both intestinal epithelial cells and mucin was demonstrated in vitro. In addition, two sets of in vivo experiments in 6-week-old Balb/c mice were performed to evaluate ΔmbfCRL1505 immunomodulatory activities. (A) Orally administered ΔmbfCRL1505 prior to intraperitoneal injection of the Toll-like receptor 3 (TLR3) agonist poly(I:C) significantly reduced intraepithelial lymphocytes (CD3+NK1.1+CD8αα+) and pro-inflammatory mediators (TNF-α, IL-6 and IL-15) in the intestinal mucosa. (B) Orally administered ΔmbfCRL1505 prior to nasal stimulation with poly(I:C) significantly decreased the levels of the biochemical markers of lung tissue damage. In addition, reduced recruitment of neutrophils and levels of pro-inflammatory mediators (TNF-α, IL-6 and IL-8) as well as increased IFN-β and IFN-γ in the respiratory mucosa were observed in ΔmbfCRL1505-treated mice when compared to untreated control mice. The immunological changes induced by the ΔmbfCRL1505 strain were not different from those observed for the wild-type CRL1505 strain. Although it is generally accepted that the expression of adhesion factors is necessary for immunobiotics to induce their beneficial effects, it was demonstrated here that the mbf protein is not required for L. rhamnosus CRL1505 to exert its immunomodulatory activities in local and distal mucosal sites. These results are a step forward towards understanding the mechanisms involved in the immunomodulatory capabilities of L. rhamnosus CRL1505.  相似文献   
32.
This paper proposes an information model for tracing CNC manufacturing operations. The objective of the model is to assure that traceability data is comprehensive and available for every CNC machined product, independent of the relationship between the subcontractor and the contractor. The prominent feature of the model is a link between CNC report data for a product instance, the CAD design and the CAM data. This link enables users to browse the traceability data and understand the relationships between the manufacturing process, the CAD design and the CAM data. The link is independent of the systems used to build the CAD and CAM data, and allows the users to be sure the manufactured product contains the required characteristics. Then if a product instance fails, this linkage will make possible to analyze the trace data and identify any exceptions or unusual conditions in the manufacturing process.  相似文献   
33.
One of the prime reasons inhibiting the widespread use of discrete-event simulation in construction planning is the absence of appropriate visual communication tools. Visualizing modeled operations in 3D is arguably the best form of communicating the logic and the inner working of simulation models and can be of immense help in establishing the credibility of analyses. New software development technologies emerge at incredible rates that allow engineers and scientists to create novel, domain-specific applications. The authors capitalized on a computer graphics technology based on the concept of the scene graph to design and implement a general-purpose 3D visualization system that is simulation and CAD-software independent. This system, the Dynamic Construction Visualizer, enables realistic visualization of modeled construction operations and the resulting products and can be used in conjunction with a wide variety of simulation tools. This paper describes the scene graph architecture and the frame updating algorithms used in designing the Dynamic Construction Visualizer.  相似文献   
34.
This paper introduces a new stabilized finite element method based on the finite calculus (Comput. Methods Appl. Mech. Eng. 1998; 151 :233–267) and arbitrary Lagrangian–Eulerian techniques (Comput. Methods Appl. Mech. Eng. 1998; 155 :235–249) for the solution to free surface problems. The main innovation of this method is the application of an overlapping domain decomposition concept in the statement of the problem. The aim is to increase the accuracy in the capture of the free surface as well as in the resolution of the governing equations in the interface between the two fluids. Free surface capturing is based on the solution to a level set equation. The Navier–Stokes equations are solved using an iterative monolithic predictor–corrector algorithm (Encyclopedia of Computational Mechanics. Wiley: New York, 2004), where the correction step is based on imposing the divergence‐free condition in the velocity field by means of the solution to a scalar equation for the pressure. Examples of application of the ODDLS formulation (for overlapping domain decomposition level set) to the analysis of different free surface flow problems are presented. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
35.
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This paper proposes the solution of tasks set required for autonomous robotic group behavior optimization during the mission on a distributed area in a cluttered hazardous terrain.The navigation scheme uses the benefits of the original real-time technical vision system(TVS)based on a dynamic triangulation principle.The method uses TVS output data with fuzzy logic rules processing for resolution stabilization.Based on previous researches,the dynamic communication network model is modified to implement the propagation of information with a feedback method for more stable data exchange inside the robotic group.According to the comparative analysis of approximation methods,in this paper authors are proposing to use two-steps post-processing path planning aiming to get a smooth and energy-saving trajectory.The article provides a wide range of studies and computational experiment results for different scenarios for evaluation of common cloud point influence on robotic motion planning.  相似文献   
36.
The anodic behaviour of three different copper electrodes in sulphuric acid medium was investigated using cyclic voltammetry in the potential range between the rest potentialE i=0=–0.34 V and +0.80 V vs the Hg, Hg2SO4/K2SO4 saturated (MSE) reference electrode. Arsenic dissolved in the electrode matrix as well as oxygen dissolved in solution were found to delay passivation. The anodic peak current density was proportional to the square root of the potential sweep rate in two consecutive domains. An unusual break was observed for high scan rates (>50 m V s–1) and was attributed to an increase of the medium viscosity because of the large gradient of concentration near the electrode surface. On the other hand, current oscillations, usually observed in the anodic processes of metallic electrodes, have been studied as a function of the electrode vertical/horizontal positions. Gravity has been found to affect both the frequency and the amplitude of the oscillations. X-ray diffraction measurements conducted on galvanostatically electrolyzed samples revealed, besides copper metal, the presence of copper sulfate pentahydrate and trihydrate for Cu–As and Cu–Sb, respectively. SEM analysis showed the existence of preferential domains of white product on a darker background of metallic copper or copper oxides.  相似文献   
37.
In the framework of the I-series of Recommendations, layer 1 specifications for ISDN user-network interfaces are given in Recommendation I.430 for the basic access(2B + D)at 144 kbits/s, and in Recommendation I.431 for the primary access at 1544 and 2048 kbits/s. The former Recommendation contains a completely new set of procedural, functional, and electrical characteristics whose definition was started during the last CCITT Study Period and is expected to be completed by the end of the present CCITT Study Period. Moreover, the latter Recommendation is largely based on functional and electrical characteristics of existing Recommendation G.703, which gives specifications for the physical/electrical characteristics of the hierarchical digital interface.  相似文献   
38.
A finite element formulation is applied to study Lamb wave scattering in homogeneous and sandwich isotropic plates. Dispersion curves are calculated in a simple and automatic way by solving a quadratic eigenproblem. A meshing criterion to obtain accurate results with linear and quadratic elements is provided. An absorbing boundary condition for semi‐infinite plates is derived from this formulation by means of a truncated normal mode expansion technique, where the finite element eigenvectors are used instead of the analytical expressions for the normal modes. This non‐reflecting boundary condition is directly applicable to study Lamb wave reflection by simple obstacles such as a flat edge. In order to tackle Lamb wave diffraction problems by defects with more complex geometries, a hybrid boundary element‐finite element formulation is developed. The validity and accuracy of both formulations are checked thoroughly with a series of test problems studied by other researchers. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
39.
Polysiloxane–polyvinyl alcohol hybrid matrix was prepared by a sol–gel technique and its capacity to bind porcine pancreatic lipase investigated. The loading of 250 units g?1 support was shown to be effective, resulting in an immobilized lipase with high catalytic activity. Both free and immobilized lipases were characterized by determining the activity profile as a function of pH, temperature, substrate concentration and thermal stability. Application of the immobilized lipase in non‐conventional biocatalysis for the synthesis of surfactants and biodiesel was also analyzed. Production of sugar fatty acid esters was found to be dependent on the carbohydrate and the highest molar conversion (50% in 3–4 h of reaction) was achieved for substrates containing fructose and lauric or oleic acids. Biodiesel synthesis from babassu oil and ethanol, propanol or butanol was feasible and regardless of the kind of alcohols, results revealed that the immobilized PPL could efficiently convert triglycerides to fatty acid alkyl esters attaining yields varying from 75 to 95%. Copyright © 2007 Society of Chemical Industry  相似文献   
40.
The replacement of glucose by mannose as a means to improve recombinant protein productivity was studied for the first time in continuous cultures of Chinese hamster ovary (CHO) cells producing human recombinant tissue plasminogen activator (t-PA). Steady-state operation at two hexose levels in the inlet (2.5 and 10 mM) allowed comparing the effect of sugar type and concentration on cell metabolism and t-PA production independently of changes in specific growth rates produced by different culture conditions. An increase in biomass concentration (15–20%) was observed when using mannose instead of glucose. Moreover, specific hexose consumption rates were 20–25% lower in mannose cultures whereas specific production rates of lactate, an undesirable by-product, were 25–35% lower than in glucose control cultures. The volumetric productivity of t-PA increased up to 30% in 10 mM mannose cultures, without affecting the sialylation levels of the protein. This increase is manly explained by the higher cell concentration, and represents a substantial improvement in the t-PA production process using glucose. Under this condition, the oxygen uptake rate and the specific oxygen consumption rate, both estimated by a stoichiometric analysis, were about 10% and 25% lower in mannose cultures, respectively. These differences lead to significant differences at larger scales, as it was estimated by simulating cell cultures at different bioreactor sizes (5–5000 L). By assuming a set of regular operating conditions in this kind of process, it was determined that mannose-based cultures could allow culturing CHO cells up to 3000 L compared to only 80 L in glucose cultures at the same conditions. These facts indicate that mannose cultures may have a significant advantage over glucose cultures not only in terms of volumetric productivity of the recombinant protein but also for their potential application in large-scale productive processes.  相似文献   
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