bluuebunny/crossref_metadata_2025 huggingface dataset:
Supply and Demand Forecasting of Blast Furnace Gas Based on Artificial Neural Network in Iron and Steel Works
Authors: Zhang Qi , Gu Yan Liang , Ti Wei , Cai Jiu Ju
Published: January 2012

Abstract.Blast Furnace Gas (BFG) system of an iron and steel works was considered. The relationship of gas amount and factors about BFG generation and consumption was analyzed by grey correlationand the BP neural network prediction model of blast furnace gaswas established based on artificial neural network for forecasting thesupply and demandof BFGinthe iron and steel-making processes.The scientific forecasting of BFG generation and consumption in each process was discussed undernormal production and accidental maintenance condition. The results show that established forecasting model is high precision, small errors, and can solve effectively actual production of BFG prediction problem and decreasing BFG flare, providing theoretical basis for establishing reasonable plans in the iron and steel works.
Influence of Cutter Geometric Parameters on the Stability of Milling Process of Thin-Walled Blades
Authors: Liu Wei Wei , Gao Xiao Juan , Shan Chen Wei , Tian Wei Jun
Published: January 2012

In this paper, a new experiment procedure is proposed to study the influence of cutter parameters and clamping methods on the stability of the milling process of thin-walled blade. A dedicated fixture is designed to carry out the experiment. Simulation results show that the new clamping system can enhance the rigidity of thin-walled blade to reduce cutting deformation and chatter vibration phenomenon. Then, cutter and cutting parameters can be optimized properly to make the system obtain high rigidity and high performance stable milling process. Industrial application indicates that the new system can improve the cutting performance and ensure the cutting quality.
Physical Design of Hydraulic Synchronizer about Lifter
Authors: Guo Zhong
Published: January 2012

The hydraulic lifter is mainly used in automobile testing and repairing. At present , most of hydraulic lifter adopts two cylinders structure, and the synchronization of two cylinders is realized by the connection of steel wire and chain. The problem of this lifter is under most circumstances only one cylinder is working, and another cylinder is moving positively by the pull of steel wire. To solve this problem, through adopting an unique three-gear structure which can guarantee the flow capacity to each cylinder is very even, this paper develops a good property, low cost, simple structure and easy installing synchronizer of hydraulic lifter. The hydraulic lifter installing this synchronizer can delete the original steel wire and chain. The experiment shows that the error of output flow capacity to each cylinder is very small and synchronizing precision is very high.
Non-Math-Modelling Data Analytical Methods Base on Artificial Neural Networks (ANNs) Applied to Optimize Preparation of Norcantharidin-Loaded Chitosan Nanoparticles
Authors: Liu Yang , Zhang Wei , Zhang Xue Nong
Published: January 2012

The artificial neural networks (ANNs) non-modeling methods were selected to optimize the preparation of loading norcantharidin chitosan nanoparticles (NPs) by ionic cross-linkage. A multiple regression model was constructed for fitting several preparation factors and each of the factor level values was arranged in the L9(34) design table and their linear weighted sum of the normalized value was taken as optimized object. A Back-Propagation (BP) network (3×7×2) in ANNs was created and trained for further checking the optimal results and the trained network was applied to simulate the experiment system and screen the optimal conditions. Finally, the best condition was obtained.
Study on Non Energy Saving Status Detection of Groundwater Heat Pump System Using Artificial Neural Network Method
Authors: Wang Zhi Wei , Peng Yi , Zhang Zhong He , Cao Wei , Li Peng
Published: January 2012

Presents two types of characteristic data: basic characteristic parameters and index characteristic parameters for non energy saving status detection (NESSD) of groundwater heat pump (GWHP) system, establishes the relationship database between characteristic data and fault factors of NESSD. For three kinds of improving back propagation (BP) algorithms: Variable Learning Rate (VLR) BP algorithm, Scaled Conjugate Gradient (SCG) BP algorithm, and Levenberg-Marquardt (LM) BP algorithm, these various algorithms’ comparative study had been conducted on the GWHP system’s NESSD. The optimal algorithm among them is determined and the GWHP system’s NESSD as cases studies can be carried out based on the most suitable BP algorithm.
Study on the Optimization of Multi-Factor Influencing Ice Thermal Storage Air Conditioning System Economy
Authors: Wang Zhi Wei , Yang Qiu Li , Zhang Lei Min , Han Li Ping , Sun Jie
Published: January 2012

On the basis of dynamic hourly cooling load, an optimal target function was taken as the minimization of sum of system fist cost and operation cost etc., within life cycle for ice thermal air conditioning system, the mathematics model of system optimization was established, and solved based on the external point penalty function method with step accelerate algorithm, using VB.NET for writing calculation program, taking ice thermal air conditioning systems for typical public buildings (an office building, a 4 star level hotel, a large scale store) as study objectives, the optimal calculations and analysis were carried out to multi-factor such as building load profile characteristics, discharge rate, and electrical price structure. Results in this paper provide technical information and reference for designer and operator.
Application of Adaptive Weighted Fusion in Robot Multi-Sensor Ranging System
Authors: Jiao De Qiang , Pang Li Li , Teng Yu Juan
Published: January 2012

Ultrasonic seniors and infrared sensors are utilized in the robot to range and locate. The precision of the whole system is often impaired. In order to improve the system’s precision, the method of adaptive weighted fusion algorithm basing on minimum mean square error is employed in this paper. According to the experimental results, this method is highly effective in the further improvement of the system ranging precision.
Infrared Object Tracking Algorithm Based on Online AdaBoost
Authors: Li Jun Shan , Zhao Fang Zhou , Zhu Ying Hong , Yang Wei
Published: January 2012

An online AdaBoost based tracking algorithm in FLIR imagery is proposed, where tracking is formulated as a binary classification problem. The object features are selected adaptively via online boosting. And then, a strong classifier is built on the weak classifiers. The confidence map of consecutive image frame is created by the strong classifier. The object localization is realized by detecting maximum of the confidence map using mean shift. The weak classfiers are updated according to the new samples to improve the discriminative ability to the object appearance and complex scene. Experiment results verify the effectives and robustness of this tracking algorithm which can improve the tracking performance efficiently.
Model Simulation of Electronic Unit Pump Diesel Engine Oriented to Control
Authors: Wang Jun , Han Shu , Zhang You Tong
Published: January 2012

To broaden the application range of hardware in loop simulation for electronic controlled unit, study on model simulation of electronic unit pump diesel engine oriented to control is made, the requirement and selection of simulation model oriented to control in electronic unit pump diesel engine is provided, model of simplified nonlinearity in diesel engine and electronic unit pump system are established in Matlab/Simulink, model verification shows that this model can achieve relative accuracy, by means of calculation time and parameter, different calculation step and method affecting model output is analyzed and compared. Real engine model is applied into hardware-in-loop simulation test, its results show that model can perform real-time ECU hardware-in-loop simulation test accurately.
Analysis on Dynamic Lubrication Characteristics of Gas Film in Hard Disk System
Authors: Yao Hua Ping , Ping Huang , Chen Yang Zhi
Published: January 2012

The dynamic response of the slider to external interference is analyzed through solving eqations simultaneously of the momentum equations and the time-dependent modified Reynolds equation based on the FK-Boltzmann modified model. Analysis software of autonomous copyright was produced, and the number of the copyright is 2009SR039126. Using this software, the dynamic response curves of the slder under different shocks were obtained, and the numerical results show that under an external motivation the significant vibration is produced. but the slider is capable of returning to the equilibrium position in 0.006ms. Then the lubrication function parameters are calculated, and variable rules of the values also were analyzed. The results shows the oscillation of slider in up-and-down direction have a larger effect on the film lubrication function, yet in the rolling direction the influence is the smallest. Consequently, the fluctuation in up-and-down direction is the main factor of affecting the dynamic lubrication function.
Application of Double Closed-Loop Control to the Steady-State Regulation and Control of Underwater Vehicle
Authors: Liu Liang , Zhai Yu Yi , Lu Wen Jie , Luo Huan Xin , Li Yu
Published: January 2012

In this paper, the speed control system controlled by motor speed was designed to control forward speed of underwater robot precisely. Based on the theory of double closed-loop speed control, motor control system was modeled firstly, and then regulator parameters were designed based on the engineering approaches. According to the characteristics of forward movement, the mechanical construction of sub-mini underwater robots and the comparison of various system designs, the double closed-loop regulator parameters of sub-mini underwater robots were obtained. And the propulsion system of sub-mini underwater robots was equipped with speed and current double closed-loop control. All the experimental results showed that within a certain range of motor speed, no static error could be guaranteed and the variable speed of underwater vehicle could be achieved.
Development of Omni-Directional Mobile Manipulator
Authors: Zhao Jie , Ma Liang , Yan Ji Hong , Gao Yong Sheng
Published: January 2012

An Omni-directional mobile manipulator with capability of zero-radius rotation is developed. Mechanism structure of the mobile platform and the manipulator are introduced, and the wheel model of the robot is designed with differential compensation structure. Multi-sensor system comprising ultrasonic sensors, infrared sensors and force/torque sensor are used for achieving precise control for the robot. Meanwhile, motion control of the mobile platform is analyzed, and servo control based on hierarchical structure of the manipulator is proposed. Finally, experiments of the robot are executed, and the results show the error of the platform for forward 4m is 8mm approximately after corrected by ultrasonic sensors, average error of zero-radius rotation is 3.7658mm, average error of re-orientation motion is 0.3mm, which verify the proposed omni-directional mobile manipulator designed reasonable, and can achieve precise operation effectively.
Application and Characterization of 12-Phase AC Arc for Glass in-Flight Melting
Authors: Yao Yao Chun , Watanabe Takayuki , Yatsuda Kazuyuki
Published: January 2012

A stable 12-phase AC arc was successfully generated and applied in the field of glass in-flight melting, the arc behavior was characterized by image analysis. The effects of electrode configuration and sheath gas flow rate on arc and melting behavior of granulated glass raw material were investigated. Results show that different electrode configurations leads to various arc discharge and high-temperature region. The luminance area with high-temperature region and its fluctuation reflect the change of arc discharge behavior. The vitrification degree of glass raw material is mostly dependent on the center temperature of arc. As the sheath gas flow rate increases, the ratio of luminance area decreases and the center temperature of arc increases.
Calculation of Radial Active Magnetic Bearing Electromagnetic Force under Eccentric Rotor
Authors: Liu Xiao Jing , Hu Ye Fa
Published: January 2012

As for active magnetic bearing, ordinary electromagnetic force formula based on air gap well-distributed. However, radial active magnetic bearing always face the situation that the rotor is eccentric and the air gap doesn’t well-distributed. This paper gives the calculation method of the electromagnetic force at that situation through calculating the air gap and using integrative approach. Then analysis the influence factors---eccentric rotor distance from center and eccentric angle to electromagnetic force. The result can provide the basis for suspension characteristic of active magnetic bearing.
Strength of Screw Thread in Vibration Tapping
Authors: Huang Wei Lei , Wang Gui Cheng
Published: January 2012

Screw thread connection is a common way of detachable connection. The invalidation of screw thread connection will lead to mechanical failure or even retirement. Vibration tapping is essentially a kind of high-energy impact cutting which increases the rigidity of the tool. Composite vibration tapping simultaneously with repeated cutting action reduces the surface recovery of plastic materials and enhances metal cutting rate. Theoretical study and experimental results show that vibration tapping improves the metal cutting rates, enhances the machining accuracy and makes screw thread connection assembly easier. At the same time, vibration tapping process does not reduce the strength of screw thread. As the screw thread can be more uniformed cut at different depths, vibration tapping enhances the strength of screw thread slightly.
Dynamic Analysis of Nonlinear Anti-Resonance Vibration Machine Based on General Finite Element Method
Authors: Jiao Chun Wang , Liu Jie , Wang Qian Qian
Published: January 2012

The operation principle of anti-resonance vibration machine was analyzed. The dynamic model of anti-resonance vibration machine with nonlinear spring was established. A new method for solving nonlinear equation based on general finite element method was put forward, the solution was compared with numerical solution, the validity of the solving method was validated. Then the affection of nonlinear and dynamics parameters to the amplitude stabilization was analyzed. the conclusion can be drown as: when the anti-resonance frequency ratio is 1~2,increase the nonlinear of spring can improve the amplitude stabilization, when the anti-resonance ratio is bigger than 3,there is less affection to the amplitude stabilization by nonlinear of spring. The amplitude stabilization can be improved by increasing anti-resonance frequency ratio.
Effect of UF/Epoxy Microcapsules on Cement Composite
Authors: Ni Zhuo , Du Xue Xiao , Wang Shuai , Xing Feng , Huang Zhan
Published: January 2012

Effect of microcapsules on cement composites has been studied. The hydration of cement composite using microcapsules is studied by XRD and thermal techniques, showing that the addition of microcapsules has little affect on the hydration of cement. The pore size distribution and surface area of the cement composite with microcapsule are analyzed, showing a reduction in the pore content of cement composite and makes the pores smaller, which would improve durability and impermeability for designed materials. Damaging on cement and composites containing microcapsules and self-healing of these damagings can be reflected by the changes in their bending strength. When the cracks were generated in the composite, the microcapsules can release adhesive to fill in the space between the crackings, preventing cracking further growth.
Longitudinal Aerodynamics of a Canard Guided Spin Stabilized Projectile
Authors: Ji Xiu Ling , Wang Hai Peng , Zeng Shi Ming , Jia Chen Yang
Published: January 2012

Navier–Stokes simulation is performed on a canard guided spinning projectile for different attack angles and circumferential position angles of canard over the Mach number range of 1.8–2.2. The computational Magnus moment coefficients of test case are validated with available experimental data of a Secant-Ogive-Cylinder-Boattail (SOCBT) configuration at Mach 3, demonstrating that the method can provide an accurate and viable approach for this problem. The aim of the present study is to provide a detailed understanding of the effects of canard with different circumferential position angles on longitudinal aerodynamic coefficients at three supersonic speeds and various angles of attack. And the results show that normal force coefficients and pitch moment coefficients vary periodically with the circumferential position angles of canard.
Mechanical Analysis of Porous Concrete Base in Asphalt Pavement
Authors: Suo Li Jun , Hu Xia Guang
Published: January 2012

In China, it is fact that porous concrete base has been used in the construction of asphalt pavement in recent years because porous concrete base has good performance. However, Reasonable design method has not been put forward so far. Therefore, it is necessary to analyze load stress and thermal stress of asphalt pavement which includes porous concrete base in order to put forward theoretical basis for pavement design method. In the paper, three–dimension finite element model of asphalt pavement, which includes porous concrete base and asphalt surface, is created for the purpose of studying load stress and thermal stress of porous concrete base in asphalt pavement. Based on numerical method of three–dimension finite element model, finite element software, such as ANSYS, is employed to study load stress and thermal stress of porous concrete base in asphalt pavement. After that, the effect of different factors on stress is studied, and the factors include thickness of surface, thickness of base and ratio of base’s modulus to foundation’s modulus. Finally, calculation results for stress are compared with each other, and it shows that load stress of porous concrete base decreases with increase of base’s thickness, while thermal stress of porous concrete base increases with increase of base’s thickness. Load stress and thermal stress of porous concrete base decrease with increase of surface’s thickness. Load stress and thermal stress of porous concrete base increase with increase of ratio of base’s modulus to foundation’s modulus.
Applying Life Cycle Six Sigma in Tolerance Design Methodology
Authors: Wu Jian Jun , Wang Yi Zhen
Published: January 2012

Setting of tolerances to meet a required specification of quality characteristic and keep low manufacturing cost is one of common problems in the process quality control. But generally traditional tolerance design only focus on cost of manufacturing, few consider product Life Cycle Cost. In these situations, to obtain a satisfactory six sigma quality level as well as keep lower life cycle total cost should be considered. This paper expands tolerance optimization based on the manufacturing cost to the product life cycle cost, which can improve product quality to the six sigma level and keep lower LCC simultaneously.
Study on Effects of High-Altitude Electromagnetic Pulse to Engine Electronic Control System
Authors: Yang Sheng Hui , Tang Yan Feng , Liu Xiang Kai , Liu Jin Hua
Published: January 2012

It is difficult to identify whether the ECS of a engine can overcome the HEMP environment, and if there are influences existing, how it will be affected and what extent it can. On the basis of discussing the occurring mechanics and characteristics of HEMP, a route to study the effects of the engine ECS under HEMP environment has been researched. Through the simulation of the HEMP, a laboratory test has been designed and carried out, and the influence of the engine ECS under HEMP has been analyzed. The research indicated that the engine ECS is susceptibility to the HEMP, the main damage mode is soft and transiency damage, it can make the control signal confusion and can even result in the suspension of work, but it can not make permanent hard damage to the ECS, and there are no evidence to show that the HEMP can result in an accumulation damage to the tested engine ECS.
Features and Industrial Applications of Combined Directed Valve Tray
Authors: Zhang Jie Xu , Zhang Cheng Fang
Published: January 2012

To increase the efficiency of float valve tray in plate column, a combined directed valve tray was developed. Comparative analysis of tray pressure drops, entrainments, weeping rates and mass transfers was conducted between the widely used V1-type float valve trays and the combined directed valve tray. The applications of the combined directed valve tray in atmospheric pressure device, catalytic cracking unit and gas fractionation device were also listed, which indicated that it was a significant improvement of float valve tray.
Design of Bionic Flapping-Wing Propulsion Device
Authors: Xing Rong , Song Bao Wei , Mao Zhao Yong , Ding Hao
Published: January 2012

The underwater vehicle has never been able to shake off the mode of pushing forward by the propeller and changing motion with underwater fin rudder. However, this traditional propeller propulsion has many shortcomings, such as a low utilization rate of energy and poor flexibility. In this passage, through the analysis of the movement of sea turtles, a brand-new propulsion project is proposed, which is Flapping-Wing propulsion. In such a limited way to proceed forward, the design can be realized like turtles campaign.
Robust Control of Double-Machine Wind Turbines with DFIG Using Hamiltonian Energy Method
Authors: Wang Bing , Yuan Xiao Ling , Zhu Jin
Published: January 2012

- In this paper, the robust control problem of the doubly fed induction generator (DFIG) wind turbines is investigated based on Hamiltonian energy method. A nonlinear design method is proposed for the double-machine system, such that the closed-loop system is stable simultaneously under the action of the controller. Moreover, we study the robust control problem of double-machine system in the presence of disturbances. On the basis of the proposed theorem, the Hamiltonian controller is designed to render the closed-loop system finite-gain stable. In order to illustrate the effectiveness of the proposed method, the simulations are performed which show that the gotten nonlinear controller can enhance the transient stability and improve the robustness property of the closed-loop system.
Limit Analysis of Supporting Pressure for Failure Surface of Deep-Buried Tunnel with Nonlinear Failure Criterion
Authors: Huang Kan , Liu Bao Chen , Peng Jian Guo , Huang Fu
Published: January 2012

The collapse surface of surrounding rock induced by the excavation has significant influence on the stability and supporting structures of deep-buried tunnel since located in high in-situ stress field. Based on the assumption of curved velocity discontinuity surface, the internal dissipated power along the surface was calculated in the framework of Power-Law nonlinear failure criterion. In considering the role of supporting forces, an objective function composed of external rate of work and the internal energy rate of dissipation was constructed by using the upper bound theorem of limit analysis, and the analytical expression of collapse surface was obtained with the help of variational calculation. The effect of parameters on the collapse surface was analyzed. It is found that the height and width of the collapse block increased with the rise of nonlinear coefficient m, which illustrate that the nonlinear coefficient m has significant influence on the shape of collapse block. In the limit state, the height and width of the collapse block increase with the growth of supporting pressure.
Research on Analysis and Repairing for Metal Structure Cracks of Portal Crane
Authors: Wang Xiao Ping , Xiao Han Bin
Published: January 2012

Crack in the port crane which is prevalent in the metal structure of crane is a serious threat to the safety use of crane, therefore, it is very important to study on the production and repair of the cracks. This article takes the actual operating portal crane as an example to study on the crack locations and monitoring methods for metal structure of port crane, with the analysis for the reason of crane load bearing structure’s cracks ,this paper gives the common repair method for metal structure crack for cranes on this basis.
Epidermal Cadm1 Expression Promotes Autoimmune Alopecia via Enhanced T Cell Adhesion and Cytotoxicity
Authors: Giangreco Adam , Hoste Esther , Takai Yoshimi , Rosewell Ian , Watt Fiona M.
Published: December 2011

Autoimmune alopecia is characterized by an extensive epidermal T cell infiltrate that mediates hair follicle destruction. We have investigated the role of cell adhesion molecule 1 (Cadm1; Necl2) in this disease. Cadm1 is expressed by epidermal cells and mediates heterotypic adhesion to lymphocytes expressing class 1-restricted T cell-associated molecule (CRTAM). Using a murine autoimmune alopecia model, we observed an increase in early-activated cytotoxic (CD8-restricted, CRTAM-expressing) T cells, which preferentially associated with hair follicle keratinocytes expressing Cadm1. Coculture with Cadm1-transduced MHC-matched APCs stimulated alopecic lymph node cells to release IL-2 and IFN-γ. Overexpression of Cadm1 in cultured human keratinocytes did not promote cytokine secretion, but led to increased adhesion of alopecic cytotoxic T cells and enhanced T cell cytotoxicity in an MHC-independent manner. Epidermal overexpression of Cadm1 in transgenic mice led to increased autoimmune alopecia susceptibility relative to nontransgenic littermate controls. Our findings reveal that Cadm1 expression in the hair follicle plays a role in autoimmune alopecia.
Thy-1 (CD90) Is an Interacting Partner for CD97 on Activated Endothelial Cells
Authors: Wandel Elke , Saalbach Anja , Sittig Doreen , Gebhardt Carl , Aust Gabriela
Published: December 2011

Leukocyte recruitment in response to inflammatory signals is governed, in part, by binding to Thy-1 (CD90) on activated endothelial cells (EC). In this study, we characterized the adhesion G-protein coupled receptor CD97, present on peripheral myeloid cells, as a novel interacting partner for Thy-1. CD97 was upregulated on polymorphonuclear cells (PMNC) of patients with psoriasis. In psoriatic skin lesions, CD97+ myeloid cells colocalized with Thy-1+ EC of small vessels in microabscesses, suggesting an interaction between CD97 and Thy-1 that was further examined by adhesion and protein-binding assays. PMNC and cell lines stably overexpressing CD97 adhered specifically to Thy-1+–activated human dermal EC, Thy-1+ CHO cells, and immobilized Thy-1 protein. Binding of the CD97+ CHO clones correlated with their CD97 expression level. Soluble CD97 bound specifically to immobilized Thy-1 protein, as well as Thy-1+–activated EC and CHO cells. In all assays, cellular adhesion or protein binding was blocked partially by CD97 and Thy-1–blocking mAb. Our data suggested that CD97 interacts via its stalk with Thy-1 because mAb directed to the stalk of CD97 showed stronger blocking compared with mAb to its epidermal growth factor-like domains, and binding was calcium independent. Moreover, soluble CD97 without the stalk and soluble EMR2, containing highly homologous epidermal growth factor-like domains but a different stalk, failed to bind. In summary, binding of leukocytes to activated endothelium mediated by the interaction of CD97 with Thy-1 is involved in firm adhesion of PMNC during inflammation and may play a role in the regulation of leukocyte trafficking to inflammatory sites.
RANKL Induces Organized Lymph Node Growth by Stromal Cell Proliferation
Authors: Hess Estelle , Duheron Vincent , Decossas Marion , Lézot Frédéric , Berdal Ariane , Chea Sylvestre , Golub Rachel , Bosisio Mattéo R. , Bridal S. Lori , Choi Yongwon , Yagita Hideo , Mueller Christopher G.
Published: December 2011

RANK and its ligand RANKL play important roles in the development and regulation of the immune system. We show that mice transgenic for Rank in hair follicles display massive postnatal growth of skin-draining lymph nodes. The proportions of hematopoietic and nonhematopoietic stromal cells and their organization are maintained, with the exception of an increase in B cell follicles. The hematopoietic cells are not activated and respond to immunization by foreign Ag and adjuvant. We demonstrate that soluble RANKL is overproduced from the transgenic hair follicles and that its neutralization normalizes lymph node size, inclusive area, and numbers of B cell follicles. Reticular fibroblastic and vascular stromal cells, important for secondary lymphoid organ formation and organization, express RANK and undergo hyperproliferation, which is abrogated by RANKL neutralization. In addition, they express higher levels of CXCL13 and CCL19 chemokines, as well as MAdCAM-1 and VCAM-1 cell-adhesion molecules. These findings highlight the importance of tissue-derived cues for secondary lymphoid organ homeostasis and identify RANKL as a key molecule for controlling the plasticity of the immune system.
Transient TLR Activation Restores Inflammatory Response and Ability To Control Pulmonary Bacterial Infection in Germfree Mice
Authors: Fagundes Caio T. , Amaral Flávio A. , Vieira Angélica T. , Soares Adriana C. , Pinho Vanessa , Nicoli Jacques R. , Vieira Leda Q. , Teixeira Mauro M. , Souza Danielle G.
Published: December 2011

Mammals are colonized by an astronomical number of commensal microorganisms on their environmental exposed surfaces. These symbiotic species build up a complex community that aids their hosts in several physiological activities. We have shown that lack of intestinal microbiota is accompanied by a state of active IL-10–mediated inflammatory hyporesponsiveness. The present study investigated whether the germfree state and its hyporesponsive phenotype alter host resistance to an infectious bacterial insult. Experiments performed in germfree mice infected with Klebsiella pneumoniae showed that these animals are drastically susceptible to bacterial infection in an IL-10–dependent manner. In germfree mice, IL-10 restrains proinflammatory mediator production and neutrophil recruitment and favors pathogen growth and dissemination. Germfree mice were resistant to LPS treatment. However, priming of these animals with several TLR agonists recovered their inflammatory responsiveness to sterile injury. LPS pretreatment also rendered germfree mice resistant to pulmonary K. pneumoniae infection, abrogated IL-10 production, and restored TNF-α and CXCL1 production and neutrophil mobilization into lungs of infected germfree mice. This effective inflammatory response mounted by LPS-treated germfree mice resulted in bacterial clearance and enhanced survival upon infection. Therefore, host colonization by indigenous microbiota alters the way the host reacts to environmental infectious stimuli, probably through activation of TLR-dependent pathways. Symbiotic gut colonization enables proper inflammatory response to harmful insults to the host, and increases resilience of the entire mammal-microbiota consortium to environmental pressures.
Early Responding Dendritic Cells Direct the Local NK Response To Control Herpes Simplex Virus 1 Infection within the Cornea
Authors: Frank Gregory M. , Buela Kristine-Ann G. , Maker Dawn M. , Harvey Stephen A. K. , Hendricks Robert L.
Published: December 2011

Dendritic cells (DCs) regulate both innate and adaptive immune responses. In this article, we exploit the unique avascularity of the cornea to examine a role for local or very early infiltrating DCs in regulating the migration of blood-derived innate immune cells toward HSV-1 lesions. A single systemic diphtheria toxin treatment 2 d before HSV-1 corneal infection transiently depleted CD11c+ DCs from both the cornea and lymphoid organs of CD11c-DTR bone marrow chimeric mice for up to 24 h postinfection. Transient DC depletion significantly delayed HSV-1 clearance from the cornea through 6 d postinfection. No further compromise of viral clearance was observed when DCs were continuously depleted throughout the first week of infection. DC depletion did not influence extravasation of NK cells, inflammatory monocytes, or neutrophils into the peripheral cornea, but it did significantly reduce migration of NK cells and inflammatory monocytes, but not neutrophils, toward the HSV-1 lesion in the central cornea. Depletion of NK cells resulted in similar loss of viral control to transient DC ablation. Our findings demonstrate that resident corneal DCs and/or those that infiltrate the cornea during the first 24 h after HSV-1 infection contribute to the migration of NK cells and inflammatory monocytes into the central cornea, and are consistent with a role for NK cells and possibly inflammatory monocytes, but not polymorphonuclear neutrophils, in clearing HSV-1 from the infected cornea.
TLR2 Activation Enhances HIV Nuclear Import and Infection through T Cell Activation-Independent and -Dependent Pathways
Authors: Ding Jian , Chang Theresa L.
Published: December 2011

TLR2 activation plays a crucial role in Neisseria gonorrheae-mediated enhancement of HIV infection of resting CD4+ T cells. We examined signaling pathways involved in the HIV enhancing effect of TLR2. TLR2 but not IL-2 signals promoted HIV nuclear import; however, both signals were required for the maximal enhancing effect. Although TLR2 signaling could not activate T cells, it increased IL-2–induced T cell activation. Cyclosporin A and IkBα inhibitor blocked TLR2-mediated enhancement of HIV infection/nuclear import. PI3K inhibitor blocked HIV infection/nuclear import and T cell activation and exerted a moderate inhibitory effect on cell cycle progression in CD4+ T cells activated by TLR2/IL-2. Blockade of p38 signaling suppressed TLR2-mediated enhancement of HIV nuclear import/infection. However, the p38 inhibitor did not have a significant effect on T cell activation or TCR/CD3-mediated enhancement of HIV infection/nuclear import. The cell cycle arresting reagent aphidicolin blocked TLR2- and TCR/CD3-induced HIV infection/nuclear import. Finally, cyclosporin A and IκBα and PI3K inhibitors but not the p38 inhibitor blocked TLR2-mediated IκBα phosphorylation. Our results suggest that TLR2 activation enhances HIV infection/nuclear import in resting CD4+ T cells through both T cell activation-dependent and -independent mechanisms.
IL-13 Regulates Th17 Secretion of IL-17A in an IL-10–Dependent Manner
Authors: Newcomb Dawn C. , Boswell Madison G. , Huckabee Matthew M. , Goleniewska Kasia , Dulek Daniel E. , Reiss Sara , Lukacs Nicholas W. , Kolls Jay K. , Peebles R. Stokes
Published: December 2011

IL-13 is a central mediator of airway hyperresponsiveness and mucus expression, both hallmarks of asthma. IL-13 is found in the sputum of patients with asthma; therefore, IL-13 is an attractive drug target for treating asthma. We have shown previously that IL-13 inhibits Th17 cell production of IL-17A and IL-21 in vitro. Th17 cells are associated with autoimmune diseases, host immune responses, and severe asthma. In this study, we extend our in vitro findings and determine that IL-13 increases IL-10 production from Th17-polarized cells and that IL-13–induced IL-10 production negatively regulates the secretion of IL-17A and IL-21. To determine if IL-13 negatively regulates lung IL-17A expression via an IL-10–dependent mechanism in vivo, we used a model of respiratory syncytial virus (RSV) strain A2 infection in STAT1 knockout (KO) mice that increases lung IL-17A and IL-13 expression, cytokines not produced during RSV infection in wild-type mice. To test the hypothesis that IL-13 negatively regulates lung IL-17A expression, we created STAT1/IL-13 double KO (DKO) mice. We found that RSV-infected STAT1/IL-13 DKO mice had significantly greater lung IL-17A expression compared with that of STAT1 KO mice and that increased IL-17A expression was abrogated by anti-IL-10 Ab treatment. RSV-infected STAT1/IL-13 DKO mice also had increased neutrophil infiltration compared with that of RSV-infected STAT1 KO mice. Neutralizing IL-10 increased the infiltration of inflammatory cells into the lungs of STAT1 KO mice but not STAT1/IL-13 DKO mice. These findings are vital to understanding the potential side effects of therapeutics targeting IL-13. Inhibiting IL-13 may decrease IL-10 production and increase IL-17A production, thus potentiating IL-17A–associated diseases.
Regulation of Eosinophil Trafficking by SWAP-70 and Its Role in Allergic Airway Inflammation
Authors: Bahaie Nooshin S. , Hosseinkhani M. Reza , Ge Xiao Na , Kang Bit Na , Ha Sung Gil , Blumenthal Malcolm S. , Jessberger Rolf , Rao Savita P. , Sriramarao P.
Published: December 2011

Eosinophils are the predominant inflammatory cells recruited to allergic airways. In this article, we show that human and murine eosinophils express SWAP-70, an intracellular RAC-binding signaling protein, and examine its role in mediating eosinophil trafficking and pulmonary recruitment in a murine model of allergic airway inflammation. Compared with wild-type eosinophils, SWAP-70–deficient (Swap-70−/−) eosinophils revealed altered adhesive interactions within inflamed postcapillary venules under conditions of blood flow by intravital microscopy, exhibiting enhanced slow rolling but decreased firm adhesion. In static adhesion assays, Swap-70−/− eosinophils adhered poorly to VCAM-1 and ICAM-1 and exhibited inefficient leading edge and uropod formation. Adherent Swap-70−/− eosinophils failed to translocate RAC1 to leading edges and displayed aberrant cell surface localization/distribution of α4 and Mac-1. Chemokine-induced migration of Swap-70−/− eosinophils was significantly decreased, correlating with reduced intracellular calcium levels, defective actin polymerization/depolymerization, and altered cytoskeletal rearrangement. In vivo, recruitment of eosinophils to the lungs of allergen-challenged Swap-70−/− mice, compared with wild-type mice, was significantly reduced, along with considerable attenuation of airway inflammation, indicated by diminished IL-5, IL-13, and TNF-α levels; reduced mucus secretion; and improved airway function. These findings suggest that regulation of eosinophil trafficking and migration by SWAP-70 is important for the development of eosinophilic inflammation after allergen exposure.
Dominant Th2 Differentiation of Human Regulatory T Cells upon Loss of FOXP3 Expression
Authors: Hansmann Leo , Schmidl Christian , Kett Janina , Steger Lena , Andreesen Reinhard , Hoffmann Petra , Rehli Michael , Edinger Matthias
Published: December 2011

CD4+CD25+FOXP3+ regulatory T cells (Treg) are pivotal for peripheral self-tolerance. They prevent immune responses to auto- and alloantigens and are thus under close scrutiny as cellular therapeutics for autoimmune diseases and the prevention or treatment of alloresponses after organ or stem cell transplantation. We previously showed that human Treg with a memory cell phenotype, but not those with a naive phenotype, rapidly downregulate expression of the lineage-defining transcription factor FOXP3 upon in vitro expansion. We now compared the transcriptomes of stable FOXP3+ Treg and converted FOXP3− ex-Treg by applying a newly developed intranuclear staining protocol that permits the isolation of intact mRNA from fixed, permeabilized, and FACS-purified cell populations. Whole-genome microarray analysis revealed strong and selective upregulation of Th2 signature genes, including GATA-3, IL-4, IL-5, and IL-13, upon downregulation of FOXP3. Th2 differentiation of converted FOXP3− ex-Treg occurred even under nonpolarizing conditions and could not be prevented by IL-4 signaling blockade. Thus, our studies identify Th2 differentiation as the default developmental program of human Treg after downregulation of FOXP3.
IL-2–Engineered nano-APC Effectively Activates Viral Antigen-Mediated T Cell Responses from Chronic Hepatitis B Virus-Infected Patients
Authors: Liu Mengya , Miao Tizong , Zhu Haoxiang , Symonds Alistair L. J. , Li Li , Schurich Anna , Maini Mala K. , Zhang Jiming , Kennedy Patrick T. F. , Li Suling , Wang Ping
Published: December 2011

Impaired function of virus-specific T cells resulting from virus persistence is one of the major mechanisms underlying the development of chronic hepatitis B viral infection. Previously, we found that IL-2 can restore the effector function of T cells rendered tolerant by Ag persistence. However, systemic administration of IL-2 induces organ pathology and expansion of T regulatory cells. In this study, we show that nano-APC with engineered HLA alleles and IL-2 deliver peptide–MHC complexes, costimulatory molecules, and IL-2 to Ag-responding T cells, resulting in enhanced expression of CD25 and activation of TCR signaling pathways, while suppressing PD-1 expression on viral-responding CD8 T cells from chronic hepatitis B virus patients. The enhanced activation of CD4 and CD8 T cells induced by IL-2–nano-APC was Ag dependent and IL-2–nano-APC did not affect T regulatory cells. At a size of 500 nm, the nano-APC effectively induce immune synapse formation on Ag-specific T cells and accumulate as free particles in the lymphoid organs. These attributes of IL-2–nano-APC or other bioadjuvant-engineered nano-APC have profound implications for their use as a therapeutic strategy in the treatment of chronic hepatitis B virus infection or other chronic viral diseases.
Role of Attachment to Surfaces on the Prevalence and Survival of Campylobacter through Food Systems
Authors: NGUYEN VU TUAN , FEGAN NARELLE , TURNER MARK S. , DYKES GARY A.
Published: December 2011

Campylobacter continues to be one of the bacterial pathogens most frequently associated with human gastrointestinal illness worldwide. Because Campylobacter primarily colonizes the intestines of animals used for food production, food products of animal origin can become contaminated with this pathogen and thus represent a significant risk factor. Despite application of numerous physical and chemical interventions to control Campylobacter during food processing, the high isolation rate of this pathogen from some retail meat products indicates that Campylobacter is able to persist from animal slaughterhouses through food systems. Given the fastidious growth requirements and high susceptibility of this pathogen to environmental conditions, the ability of Campylobacter to attach to food and food-related surfaces is likely to play an important role in food contamination and movement through food systems. This review was compiled to (i) describe how the attachment of Campylobacter to surfaces influences the prevalence and survival of the organism through food systems, (ii) examine the potential factors affecting the ability of Campylobacter to attach to surfaces, and (iii) suggest strategies for controlling this attachment process.
Treatment of Raw Poultry with Nonthermal Dielectric Barrier Discharge Plasma To Reduce Campylobacter jejuni and Salmonella enterica
Authors: DIRKS BRIAN P. , DOBRYNIN DANIL , FRIDMAN GREGORY , MUKHIN YURI , FRIDMAN ALEXANDER , QUINLAN JENNIFER J.
Published: December 2011

Nonthermal plasma has been shown to be effective in reducing pathogens on the surface of a range of fresh produce products. The research presented here investigated the effectiveness of nonthermal dielectric barrier discharge plasma on Salmonella enterica and Campylobacter jejuni inoculated onto the surface of boneless skinless chicken breast and chicken thigh with skin. Chicken samples were inoculated with antibiotic-resistant strains of S. enterica and C. jejuni at levels of 101 to 104 CFU and exposed to plasma for a range of time points (0 to 180 s in 15-s intervals). Surviving antibiotic-resistant pathogens were recovered and counted on appropriate agar. In order to determine the effect of plasma on background microflora, noninoculated skinless chicken breast and thighs with skin were exposed to air plasma at ambient pressure. Treatment with plasma resulted in elimination of low levels (101 CFU) of both S. enterica and C. jejuni on chicken breasts and C. jejuni from chicken skin, but viable S. enterica cells remained on chicken skin even after 20 s of exposure to plasma. Inoculum levels of 102,103, and 104 CFU of S. enterica on chicken breast and chicken skin resulted in maximum reduction levels of 1.85, 2.61, and 2.54 log, respectively, on chicken breast and 1.25, 1.08, and 1.31 log, respectively, on chicken skin following 3 min of plasma exposure. Inoculum levels of 102, 103, and 104 CFU of C. jejuni on chicken breast and chicken skin resulted in maximum reduction levels of 1.65, 2.45, and 2.45 log, respectively, on chicken breast and 1.42, 1.87, and 3.11 log, respectively, on chicken skin following 3 min of plasma exposure. Plasma exposure for 30 s reduced background microflora on breast and skin by an average of 0.85 and 0.21 log, respectively. This research demonstrates the feasibility of nonthermal dielectric barrier discharge plasma as an intervention to help reduce foodborne pathogens on the surface of raw poultry.
Detection of Foreign Bodies in Foods Using Continuous Wave Terahertz Imaging
Authors: LEE YOUNG-KI , CHOI SUNG-WOOK , HAN SEONG-TAE , WOO DEOG HYUN , CHUN HYANG SOOK
Published: December 2011

Foreign bodies (FBs) in food are health hazards and quality issues for many food manufacturers and enforcement authorities. In this study, continuous wave (CW) terahertz (THz) imaging at 0.2 THz with an output power of 10 mW was compared with X-ray imaging as techniques for inspection of food for FBs. High-density FBs, i.e., aluminum and granite pieces of various sizes, were embedded in a powdered instant noodle product and detected using THz and X-ray imaging. All aluminum and granite pieces (regular hexahedrons with an edge length of 1 to 5 mm) were visualized by both CW THz and X-ray imaging. THz imaging also detected maggots (length = 8 to 22 mm) and crickets (length = 35 and 50 mm), which were embedded in samples as low density FBs. However, not all sizes of maggot pieces embedded in powdered instant noodle were detected with X-ray imaging, although larger crickets (length = 50 mm and thickness = 10 mm) were detected. These results suggest that CW THz imaging has potential for detecting both high-density and low-density FBs embedded in food.