bluuebunny/crossref_metadata_2025 huggingface dataset:
Vibration Isolation Research on the Metal Rubber Damping Rod of Payload Attach Fitting
Authors: Wei Zhan Ji , Li Dong Xu , Xu Rui
Published: December 2011

In order to reduce the vibration load transmitted from the launch vehicle to the spacecraft during the launching stage, a whole-spacecraft vibration isolating method is advanced by modifying ordinary payload attach fitting (PAF). The core component of the PAF is a kind of damping rod produced by composite material encapsulating metal rubber (MR). In this paper, nonlinear equivalent damping model of the damping rod is built up. By using the model, the stiffness, damping and the transmissibility of the damping rod is studied attentively. Simulation results demonstrate that there exist nonlinear relationships between vibration parameters and the stiffness and damping characteristics of the damping rod. The damping rod can isolate high-frequency vibration as well as restrain the resonant peak effectively.
A Novel Way to Fabricate Carbon Nanotubes Reinforced Copper Matrix Composites by Friction Stir Processing
Authors: Chen Wen Liang , Huang Chun Ping , Ke Li Ming
Published: December 2011

Carbon nanotubes(CNTs) reinforced copper matrix composites were successfully produced by Friction Stir Processing (FSP). The effect of applying multiple FSP passes on the forming of composites was studied, the microstructure, microhardness and conductivity of the good forming composite were analyzed. The experimental results showed that CNTs uniformly distributed and good forming composite can be obtained by three FSP passes. Compared to the parent material, the grain size of the composite has significantly refined, and the microhardness of the composite has also greatly improved, but the conductivity of the composite has a small decrease.
The Plastic Deformation Characteristics of Crystalline Polymer Materials via Rolling Process
Authors: Qiu Jian Hui , Murata Takuya , Takahashi Kenji , Wu Xue Li
Published: December 2011

The present work investigated the variation of internal structure, molecular orientation, crystallinity and mechanical characteristics of polypropylene(PP) after rolling process. The materials plate became narrow when rolled from entrance to exit, and the internal crystalline gradually deformed and at last destroyed. Plastic deformation was discovered along the rolling direction. In this direction, the crystallinity and vickers hardness were decreased, and molecular orientation was increased. Moreover, molecular orientation had a sharp increase at the second half part of rolling sample. The tensile stress of rolled samples increased by 80% parallel to rolling direction and decreased by 22% perpendicular to rolling direction.
Grain Size Effects on the Oxidation of Two-Phase Cu-Fe-Al Alloys
Authors: Xiang Jun Huai , Wang Wei , Zhang Hong Hua , Liu Yu Wei
Published: December 2011

The oxidation behavior of thin layers of Fe-15Cu-5Al-0.3Y alloy with grain size in nanometer range, prepared by magnetron sputtering deposition on cast alloy of the same composition, was studied at700oC in 0.1MPa O2. The scales grown on the coatings consist of two layers. The outer layer is composed of an external continuous Fe oxides scale free from copper and aluminum oxides. The inner layer is very complicated, with formation of dark oxides of Fe and Al, coupled with light un-oxidized Cu-rich stringers elongated perpendicularly to the alloy surface. Some degree of internal oxidation of Fe and Al is also present within the coating layer. A grain size reduction can effectively promote the selective external oxidation of Fe.
Surface Polishing of Plasma Carburized Austenitic Stainless Steel
Authors: Zheng Shao Mei , Zhao Cheng
Published: December 2011

After being plasma carburized, the surface of AISI 316 austenitic stainless steel was covered with a layer of compact black thin-film. The surface polishing treatment, electrochemical brightening was carried out to remove the black thin-film and renew the original color of the stainless steel. The surface appearance, microstructures, micro hardness, surface roughness and corrosion resistance of the samples treated by electrochemical brightening process were analyzed. Experimental results show that the electrochemical brightening treatment can remove the black thin-film from and restore the original color of the plasma carburized stainless steel. After electrochemical brightening treatment, the thickness and surface hardness of the carburized layer were all decreased little, but the corrosion resistance was improved significantly. And the surface roughness (Ra) was lower than before. Therefore, the electrochemical surface brightening treatment can be used to improve the surface quality of the austenitic stainless steel treated by plasma carburizing.
Study on Reaction Products of B4C-CeB6/Al Composites
Authors: Peng Ke Wu , Zhang Peng , Ma He Li , Chen Ren
Published: December 2011

B4C-CeB6/Al composite was fabricated by pressureless infiltration technology. It is composed of the phases of Al, B4C, AlB2, Al3BC and CeB6, and Al4C3 is not found because of the existence of CeB6. It could identify that AlB2, CeB6, and Al3BC were formed as interfacial reaction products. Al3BC is formed on the interface of B4C and Al; therefore it connects the aluminum with the ceramic toughly. AlB2 as strip crystal is formed between B4C and Al, which has higher fracture toughness.CeB6 particles in B4C grain boundary are discovered by TEM, which caused intercrystalline rupture. Grain toughening and reinforcing, crack deflection, crack bridging is the main toughening and reinforcing mechanisms of B4C-CeB6/Al composites.
Visualisation of Cornstarches Granule with Different Amylose/Amylopectin Contents: A Combined CLSM and SEM Approach
Authors: Chen Pei , Li Yuan Zhi , Wu Xue Hui , Liu Xing Xun
Published: December 2011

The morphologies and microstructures of cornstarches with different amylose/amylopectin ratios (waxy: 0/100; maize: 23/77; Gelose 50: 50/50; Gelose 80: 80/20) were studied by a combined SEM and confocal laser scanning microscope (CLSM). CLSM allowed the visualization of cross-sections of starch granules without the need for sectioning techniques that lead to destruction of the microstructure of sample. The influence of the amylose/amylopectin ratio on the internal structures and morphologies was able to be revealed by this choice of techniques. It was found that the granules of the high-amylopectin starches were more regular in shape than those of the high-amylose starches, but the surfaces of the high-amylose starches were smoother than those of the high-amylopectin starches. The high-amylose starches (G50 and G80) were brighter than that of low-amylopectin starches (waxy and maize) under confocal laser light, and the average fluorescence intensity sequence of the granules was G80>G50>maize>waxy. Waxy and maize starches show clearly cavities and channels while G50 and G80 present bright core.
A Comparative Study on Co-Sorption of Zn(II) and As(V) by Mixed Fe/Al-PILCs Prepared at Different Calcination Temperatures
Authors: Wu Si Yuan , Zheng Hong , Weidler Peter G. , Cai Peng
Published: December 2011

With synthetic wastewater, a comparative study on co-sorption of Zn(II) and As(V) by Fe/Al-PILCs prepared at different calcination temperatures was investigated using a lab-scale batch experiment technique. The effects of relevant parameters, such as pH value of solution, adsorbent dosage and contact time were examined, respectively. The results show that sorption efficiencies of Zn(II) and As(V) by Fe/Al-PILC prepared at calcination temperatures of 300 °C are higher than those at 350 and 400 °C and the higher calcination temperature is, the lower sorption efficiencies of Zn(II) and As(V) are. Co-sorption isotherm data of Zn(II) and As(V) by Fe/Al-PILCs were fitted well to Langmuir isotherm and the maximum sorption capacities of Zn(II) and As(V) on Fe/Al-PILC (Q0) prepared at 300 °C are 13.95 and 15.87 mg/g, respectively, which are higher than those at calcination temperatures of 350 °C and 400 °C. The maximum sorption capacity of As(V) decreases more obviously with increasing calcination temperature than Zn(II) does. n>1 from Freundlich isotherm indicate that the sorption of Zn(II) and As(V) by Fe/Al-PILCs is favorable. E values from D-R model indicate that the type of sorption of Zn(II) and As(V) by Fe/Al-PILCs is physical. There is significant potential for Fe/Al-PILC prepared at calcination temperature of 300 °C as an adsorbent material for Zn(II) and As(V) removal from aqueous solutions.
Preparation, Performance and Analysis of Carbon Fibers with Dielectric Barrier Discharges Plasma Surface Treatment
Authors: Zhang Huan Xia , Wei Li
Published: December 2011

The deposition of coatings on the surface of carbon fiber will be helpful to their appli-cations. However, they are unsuitable to be deposited due to their low surface free energies, poor wettability and poor adhesions. The objective of this work is to modify carbon fibers by Dielect-ric barrier discharges (DBD) in ambient argon. The chemical and physical changes induced by the treatments on carbon fibers surface are examined using contact angle measurements and X-ray photoelectron spectroscopy (XPS). The interfacial adhesion of CF/EP composites are analysised by a single filament pull-out test. The contact angles of the plasma-treated samples are visibly reduced than the untreated samples. XPS results reveal that the carbon fibers modified with the DBD at an atmospheric pressure show a significant increase in oxygen-containing groups, such as C–O,C=O and O–C=O. The results of IFSS tests show that the treated carbon fibers composit-es could possess excellent interfacial properties with mixed resins. These results demonstrate that the surfaces of the carbon fibers samples are more active, hydrophilic and rough after plasma treatments using a DBD operating in ambient argon.
Fundamental Research of Sintering Process on Improving the Tumbler Strength of Low SiO2 Sinter
Authors: Ying Zi Wei , Chu Man Sheng , Yu Jing Kun , Xu Li Xian
Published: December 2011

In the laboratory condition, a series of experiments were carried out in a sintering pot in order to improve the tumbler strength of low SiO2 sinter. The results shows that the content of SiO2 is decreased from 4.4wt% to 3.9wt% when the ratio of serpentine is decreased from 2.2wt% to 1.0wt%, as a result, the tumbler strength and the reduction degradation index of sinter all fall down. When the ratio of serpentine is further decreased, all kinds of sintering indexes fall down rapidly. If the basicity of sinter is increased from 1.75 to 1.85, and 5wt% iron concentrate is added in sintering mixture, the content of SiO2 can be decreased to 3.9wt%~4.0wt%, meanwhile, the tumbler strength of sinter is the same as that of the reference sinter with 4.4wt% SiO2. When Niuman iron ore, Hainan iron ore and Hamosili iron ore are used as the hearth layer instead of sinter, and the basicity of sinter is increased to 1.85, the tumbler strength of sinter with 3.9wt%~4.0wt%SiO2 is the same as that of the reference sinter with 4.4wt% SiO2.
Study on the Effect of Distillation Residue in Corn Polyols Industry on Thermoplastic Starch
Authors: Bao Ni Na , Wu Hong Fa , Xue Dong Hua
Published: December 2011

This study used distillation residue obtained from bio-refinery process of corn starch and glycerol as a plasticizer to prepare thermoplastic starch (TPS). Various weight ratios of distillation residue and glycerol was investigated, HPLC method was used to analysis the components of the distillation residue. The composition and structure of TPS were evaluated by FTIR, XRD and TGA. The results indicated that with the addition of mixed plasticizers, the structure of TPS was changed obviously from a crystal state to an amorphous one with an increasing thermal stability of TPS. The better TPS structure can be obtained when the weight ratio of distillation and glycerol is 3:7.
Li(Ni1/3Co1/3Mn1/3)O2 with High Rate Capability Synthesized via a Novel Gel-Combustion Method
Authors: Mao Jing , Dai Ke Hua , Zhai Yu Chun
Published: December 2011

Li(Ni1/3Co1/3Mn1/3)O2material with high rate capability was synthesized by a novel gel-combustion method using polyvinylpyrrolidone as a polymer chelating agent and a fuel. X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) were used to study the structure, morphology and element distribution of the Li(Ni1/3Co1/3Mn1/3)O2material. XRD analysis showed that all samples were α-NaFeO2structure and Li(Ni1/3Co1/3Mn1/3)O2prepared at 900 °C had the highest c/a of 4.977 indicating the highest layered-ness. EDS scan demonstrated that the precursor was homogeneous. SEM images indicated all samples were well crystallized. Charge and discharge tests showed all samples had good rate capability. Among them, Li(Ni1/3Co1/3Mn1/3)O2prepared at 900 °C had the highest capacity and the best rate capability. It delivered 162.1 mAh•g−1at 0.25 C between 2.5 and 4.3 V and the capacity retention was about 81% compared to that of 0.25C rate.
Study of the Machining Principle and Influencing of Ultrasonic Lapping on SiC Single Crystal
Authors: Qiang Xiao
Published: December 2011

In order to resolve precision machining problem for SiC single crystal, a new ultrasonic lapping method is proposed. According to the brittle and hardness character of SiC single crystal, the principle of ultrasonic lapping is firstly introduced, and then parameters of experimental for ultrasonic lapping, such as wheel speed, grit size, vibration amplitude, frequency are given. Lastly, experimental result is analyzed by comparing ultrasonic lapping process with the conventional lapping process in the MRR and surface quality.
Calibration and Calculation of Interference in Hob Relief Grinding
Authors: Lao Qi Cheng , Ge Jing
Published: December 2011

Grinding wheel diameter is one of the most important parameter during the entire process of hob relief grinding and it must be analyzed and tested to avoid interference during the relief grinding. Graphical analytical and calculation method is proposed in this paper. Relief grinding interference issues are graphically analyzed and the formulas of relief grinding interference are derived. The interface is designed to calculate the maximum grinding wheel diameter of different parameters hob [1]. This method provides the basis for selecting grinding wheel rationally.
A Kind of Mathematical Solution of Optimization for Turning
Authors: Li Fu Yuan , Wang Jun
Published: December 2011

As a base of optimization of metal cutting, a new method of solution of optimization for single pass turning is proposed in this paper. There are three parts for this new method. Firstly, the optimal point must exist on the boundary of the feasible domain of the cutting conditions. Secondly, it is easy to add the processing of determining the boundary of feasible domain as new constraints. Thirdly, the local optimal point on every piece of line or curve of the boundary can be calculated, and finally the minimum of those local optimal points is the final optimal point. There are no local optimal points on the curves of constraints Tmin and Tmax except the intersection points. In addition, the trend of the objective function is affected by the rate . It is helpful to calculate the optimal point by computer. This approach provides a basic research on the affection of the statistics characteristic of the empirical functions used in this case.
A New Method on Illumination Measurement to Dynamic and Static Light Sources
Authors: Wang Kun Qi , Ren Guang Qi , Shao Zhu Feng
Published: December 2011

A novel measurement system for the dynamic and static light sources is designed in this paper. The method of dynamic gain adjustment measurement is proposed according to the national standards on luminous intensity of dynamic and static light sources. The method is achieved by the way that microcontroller controlled the analog switches to switch automatically in different ranges and adjust the gain automatically depend on the light intensity. By designing the overall structure of the system and using the dynamic gain adjustment method, the range of dynamic measuring illumination can be from 0.001 up to 2000 . The illumination measurement to static light source and the dynamic light source in the peak luminous intensity are achieved via the combination of interval control and dynamic gain adjustment.
Automotive Safety Monitoring Methods in Multiple Redundant
Authors: Wang Kun Qi , Shao Zhu Feng , Ren Guang Qi
Published: December 2011

For reducing the rate of false alarm what was the main problem in security monitoring of middle-low cars, multiple redundant methods was proposed to obtain reliable detecting information from the car. The multiple redundant is a method on analytical and determine the signals, it analyzed and determined the received signals that a variety of sensors detecting the same target. Then the information was sent to the owner via MMS. The remote alarm was achieved and the reliability of system was enhanced by rational designing the system, calculating the crystal frequency of wireless communication module and choosing of baud rate. Therefore, the remote monitoring of vehicle by the owner was achieved, and the problems exiting in the traditional alarm system, such as distance limitation and false alarm rate, were solved effectively.
Design on ECM Device of Engine Connecting Rod Hot-Forging Die
Authors: Jia Jian Li , Liu Jin He , Meng Sha Sha
Published: December 2011

Electrochemical machining (ECM) molding was adopted to realize hot-forging die with high hardness, complex shape, high requirement for surface quality and sound demand effect. With the object of engine connecting rod hot-forging die, ECM cathode and device of hot-forging die main cavity and flash cavity were designed. The results indicate that ECM shaping can achieve hot-forging die machining with high efficiency, lowcost, no cutting stress and cavity primary shaping, and the machined hot-forging piece coincides well with the blueprint and obtains notable economic benefit.
Research the Molybdenum Alloy Micro EDM Micro-Holes
Authors: Chen Lan
Published: December 2011

In the field of micromachining, micro electrical discharge machining (MEDM) is an important and perfect machining method for high rigid or high wearable materials, which is better than traditional methods of machining. MEDM technology is used to manufacture on-line electrodes and then minimum micro shafts with diameter of 15μm were made with these electrodes. A series of different micro-holes (e.g. Φ40μm、Φ50μm、Φ60μm) on pieces of molybdenum were manufactured with different parameters. Wastage of electrode rule was also studied.
Development of the Performance-Driven Part Library of Cylindrical Spiral Spring Based on Pro/E
Authors: Du Jiang , Cao Yan
Published: December 2011

Aiming at the problem of repeat design of cylindrical spiral spring, construction method of performance driven part library for cylindrical spiral spring in Pro/E is put forward. The performance and structural parameters of cylindrical spiral spring are firstly analyzed in terms of national standards GB1358-2009 and GB/T4357–1989. More ever, its data content and storage method is discussed, and development of the automation modeling program is lastly introduced. Spring model can be built automatically according to its load and perform by above method.
Research on the Key Technology of Multi-Target Evaluation for Products
Authors: Zhou Xian , Zhao Qing
Published: December 2011

The thesis systematically researches the theory and methodology of multi-target industrial design evaluation with computer-aided technology. A prototype of multi-target industrial design evaluation system based on the expert system technology has been structured. The system includes three sub modules：evaluation target tree, evaluation target tree model and evaluation toolkit. The construction, content and realization of the four models are discussed in details. Last, this system has been validated according to an instance.
Experimental Research on Thermal and Vibration Performance of High-Speed Spindle
Authors: Wen Huai Xing , Su Jiang Fei
Published: December 2011

Temperature data and vibration acceleration signals of both ends of high-speed spindle in different speeds are gathered by the DHDAS dynamic signal testing analysis system when spindle is in the working status. And the own analysis software and MATLAB are applied to analyze it. Temperature curves and vibration displacement curves are obtained after real and effective information is extracted. It can provide the basis for the research and analysis of spindle performance. The experiment results show that the method is real-time, efficient and has strong anti-jamming capability and small error. It can perform effectively in high-speed spindle studies.
Review of Fabrication Methods of Nanotube / Nanowire Devices
Authors: Tan Miao Miao , Zhang Zi Yi , Zhao Lin Hui , Zhang Jian Cheng
Published: December 2011

With the development of nano materials, a novel research field of NEMS forms by combining nano materials, nano-structures and nano fabrication with MEMS. Carbon nanotube (CNT) is a kind of one-dimensional nano structures which has unique mechanical, electrical and chemical properties. Using CNTs, new nano-devices with new principle or high performance would be developed. This paper reviews the assembly methods of one dimensional nanostructure and analyzes the characteristics of various methods, which provides reference for the device manufacturing methods using nanotubes/nanowires.
Ballistic Characteristics of Non-Silicon MEMS Inertial Trigger Switch
Authors: Liu Hao Bo , Niu Lan Jie , Song Yong Qiangc
Published: December 2011

The military ballistic characteristics of a new kind of non-silicon MEMS inertia trigger switch were investigated by finite element method (FEM) in this paper. Some useful results on the ballistic characteristics were obtained and the non-silicon MEMS inertia switch was proved to be highly reliable and sensitive eventually.
Finite Element Analysis of Engraving Machine as a Whole
Authors: Feng Tao , Jin Xiao Li
Published: December 2011

Based on the analytical theories of the joint surface, finite element modeling method of two kinds of joint about rails and bolts were studied. The finite element model of the engraving machine is built and its static and dynamic characterization is analyzed by the universal ANSYS. By this way, unreasonable structural design of engraving machine can be conducted, which will provide support for the optimization design of the structure. The correctness of the modeling method of joint surface is confirmed.
Overview on Emotion-Affected Behavior Selection Mechanism
Authors: Zhang Guo Feng , Wang Niu
Published: December 2011

The traditional Behavior Selection Mechanism (BSM) has two problems: it can’t be achieved autonomously under uncertainty conditions; its selection is absence of diversity under the same conditions. Being inspirited by the research achievements in emotion mechanism application to affective calculation and reinforcement learning, emotion is applied to BSM research to settle its problems. An emotion-affected mechanism is suggested. It is design-based totally; there are not the corresponding academic supports on it. Therefore, there exist three problems: the necessary elements, which it should have had, have not involved in; its architectures and emotion models are different; in addition, systematic analysis and comparisons have not been conducted among them. The suggestions are offered that the emotion-affected behavior selection mechanism should start off with mining the internal consistency among relevant research results of emotion in microeconomics, psychology, ethology, etc. Meanwhile, comparative research method will be meaningful.
A New Binocular Camera Calibration Method Based on an Improved Genetic Algorithm
Authors: Jiang Xiang Kui
Published: December 2011

In this paper,an improved genetic algorithm was proposed,which is applicable to binocular camera calibration. On the one hand, conventional encoding method is improved so that variable search interval can be adjusted adaptively. On the other hand, crossover and mutation probability is varied by using superiority inheritance principle to avoid premature question. Experimental results show that the proposed method has a higher calibration accuracy and better robustness, compared to those of non-linear calibration methods. The proposed method is able to improve the performance of global optimization effectively.
Size-Dependent Attenuation of TLR9 Signaling by Gold Nanoparticles in Macrophages
Authors: Tsai Chiau-Yuang , Lu Shiou-Ling , Hu Chia-Wen , Yeh Chen-Sheng , Lee Gwo-Bin , Lei Huan-Yao
Published: December 2011

Gold nanoparticles (GNPs), which are generally thought to be bio-inert and non-cytotoxic, have become one of the most ideal nanomaterials for medical applications. Once engulfed by phagocytes, the immunological effects of GNPs are still of concern and require detailed investigation. Therefore, this study explored the immunological significance of GNPs on TLR-mediated innate immunity in murine macrophages. GNP causes specific inhibition of TLR9 (CpG oligodeoxynucleotides; CpG-ODNs) signal in macrophages. The impaired CpG-ODN–induced TNF-α production is GNP concentration- and size-dependent in murine Raw264.7 cells: a GNP of 4 nm in size is more potent than a GNP of 11, 19, 35, or 45 nm in size. Consistent with cytokine inhibition, the CpG-ODN–induced phosphorylation of NF-κB and JNK as well as NF-κB activation are suppressed by GNPs. GNPs accumulate in lysosomes after phagocytosis and also increase TLR9-associated lysosomal cathepsin expression and activities, but this is irrelevant to TLR9 inhibition by GNPs in our studies. In addition, GNPs affected TLR9 translocation in response to CpG-ODNs and to phagosomes. Further exploring how GNPs inhibited TLR9 function, we found that GNPs could bind to high-mobility group box-1 (which is involved in the regulation of TLR9 signaling) inside the lysosomes. The current studies demonstrate that size-dependent inhibition of TLR9 function by GNP may be attributed to its binding to high-mobility group box-1.
Adiponectin Attenuates Lipopolysaccharide-Induced Acute Lung Injury through Suppression of Endothelial Cell Activation
Authors: Konter Jason M. , Parker Jennifer L. , Baez Elizabeth , Li Stephanie Z. , Ranscht Barbara , Denzel Martin , Little Frederic F. , Nakamura Kazuto , Ouchi Noriyuki , Fine Alan , Walsh Kenneth , Summer Ross S.
Published: December 2011

Adiponectin (APN) is an adipose tissue-derived factor with anti-inflammatory and vascular protective properties whose levels paradoxically decrease with increasing body fat. In this study, APN’s role in the early development of ALI to LPS was investigated. Intratracheal LPS elicited an exaggerated systemic inflammatory response in APN-deficient (APN−/−) mice compared with wild-type (wt) littermates. Increased lung injury and inflammation were observed in APN−/− mice as early as 4 h after delivery of LPS. Targeted gene expression profiling performed on immune and endothelial cells isolated from lung digests 4 h after LPS administration showed increased proinflammatory gene expression (e.g., IL-6) only in endothelial cells of APN−/− mice when compared with wt mice. Direct effects on lung endothelium were demonstrated by APN’s ability to inhibit LPS-induced IL-6 production in primary human endothelial cells in culture. Furthermore, T-cadherin–deficient mice that have significantly reduced lung airspace APN but high serum APN levels had pulmonary inflammatory responses after intratracheal LPS that were similar to those of wt mice. These findings indicate the importance of serum APN in modulating LPS-induced ALI and suggest that conditions leading to hypoadiponectinemia (e.g., obesity) predispose to development of ALI through exaggerated inflammatory response in pulmonary vascular endothelium.
Rapid In Vivo Conversion of Effector T Cells into Th2 Cells during Helminth Infection
Authors: Panzer Marc , Sitte Selina , Wirth Stefanie , Drexler Ingo , Sparwasser Tim , Voehringer David
Published: December 2011

Stimulation of the immune system by pathogens, allergens, or autoantigens leads to differentiation of CD4+ T cells with pro- or anti-inflammatory effector cell functions. Based on functional properties and expression of characteristic cytokines and transcription factors, effector CD4+ T cells have been grouped mainly into Th1, Th2, Th17, and regulatory T (Treg) cells. At least some of these T cell subsets remain responsive to external cues and acquire properties of other subsets, raising the hope that this functional plasticity might be exploited for therapeutic purposes. In this study, we used an Ag-specific adoptive transfer model and determined whether in vitro-polarized or ex vivo-isolated Th1, Th17, or Treg cells can be converted into IL-4–expressing Th2 cells in vivo by infection of mice with the gastrointestinal helminth Nippostrongylus brasiliensis. Th1 and Th17 cells could be repolarized to acquire the expression of IL-4 and lose the expression of their characteristic cytokines IFN-γ and IL-17A, respectively. In contrast, both in vitro-generated and ex vivo-isolated Treg cells were largely resistant to repolarization. The helminth-induced conversion of Th1 or Th17 cells into Th2 cells may partially explain the inverse correlation between helminth infection and protection against autoimmune disorders.
Regulation of the Inflammatory Response: Enhancing Neutrophil Infiltration under Chronic Inflammatory Conditions
Authors: Bian Zhen , Guo YaLan , Ha Binh , Zen Ke , Liu Yuan
Published: December 2011

Neutrophil (polymorphonuclear leukocytes [PMN]) infiltration plays a central role in inflammation and is also a major cause of tissue damage. Thus, PMN infiltration must be tightly controlled. Using zymosan-induced peritonitis as an in vivo PMN infiltration model, we show in this study that PMN response and infiltration were significantly enhanced in mice experiencing various types of systemic inflammation, including colitis and diabetes. Adoptive transfer of leukocytes from mice with inflammation into healthy recipients or from healthy into inflammatory recipients followed by inducing peritonitis demonstrated that both circulating PMN and tissue macrophages were altered under inflammatory conditions and that they collectively contributed to enhanced PMN infiltration. Detailed analyses of dextran sulfate sodium-elicited colitis revealed that enhancement of PMN infiltration and macrophage function occurred only at the postacute/chronic phase of inflammation and was associated with markedly increased IL-17A in serum. In vitro and ex vivo treatment of isolated PMN and macrophages confirmed that IL-17A directly modulates these cells and significantly enhances their inflammatory responses. Neutralization of IL-17A eliminated the enhancement of PMN infiltration and IL-6 production and also prevented severe tissue damage in dextran sulfate sodium-treated mice. Thus, IL-17A produced at the chronic stage of colitis serves as an essential feedback signal that enhances PMN infiltration and promotes inflammation.
The Proapoptotic Bcl-2 Family Member Bim Plays a Central Role during the Development of Virus-Induced Hepatitis
Authors: Lauer Christoph , Brunner Thomas , Corazza Nadia
Published: December 2011

The proapoptotic Bcl-2 homolog Bim was shown to control the apoptosis of both T cells and hepatocytes. This dual role of Bim might be particularly relevant for the development of viral hepatitis, in which both the sensitivity of hepatocytes to apoptosis stimuli and the persistence of cytotoxic T cells are essential factors for the outcome of the disease. The relevance of Bim in regulating survival of cytotoxic T cells or induction of hepatocyte death has only been investigated in separate systems, and their relative contributions to the pathogenesis of T cell-mediated hepatitis remain unclear. Using the highly dynamic model system of lymphocytic choriomeningitis virus-mediated hepatitis and bone marrow chimeras, we found that Bim has a dual role in the development of lymphocytic choriomeningitis virus-induced, T cell-mediated hepatitis. Although the absence of Bim in parenchymal cells led to markedly attenuated liver damage, loss of Bim in the lymphoid compartment moderately enhanced hepatitis. However, when both effects were combined in Bim−/− mice, the effect of Bim deficiency in the lymphoid compartment was overcompensated for by the reduced sensitivity of Bim−/− hepatocytes to T cell-induced apoptosis, resulting in the protection of Bim−/− mice from hepatitis.
Missionale integriteit en kontekstuele relevansie
Authors: Nel Malan
Published: December 2011

Missional integrity and contextual relevanceThe research problem addressed in this article discussed whether so-called missional local churches too often escape local contextual involvement by sending money or even people to work on their behalf ‘elsewhere’. Is it true that local churches take the easier ‘money-way’ out to save a missional public face? The hypothesis is that missional integrity is in essence to be ‘firstly’ contextual relevant ‘before’ being nationally and even globally involved in mission. A basic assumption is that every local church is a gift of God to a specifically and even geographically defined context.
MRI findings in cranial eumycetoma
Authors: Ahmed Munawwar , Sureka Jyoti , Chacko Geeta , Eapen Anu
Published: December 2011

Cranial eumycetoma (CE) due to direct inoculation of Madurella grisea into the scalp is extremely rare. We describe a case of CE caused by direct inoculation of M. grisea with the characteristic MRI findings of the "dot-in-circle" sign and a conglomeration of multiple, extremely hypointense "dots."
Lesions in the external auditory canal
Authors: Chatra Priyank S
Published: December 2011

The external auditory canal is an S- shaped osseo-cartilaginous structure that extends from the auricle to the tympanic membrane. Congenital, inflammatory, neoplastic, and traumatic lesions can affect the EAC. High-resolution CT is well suited for the evaluation of the temporal bone, which has a complex anatomy with multiple small structures. In this study, we describe the various lesions affecting the EAC.
Species Delimitation and Global Biosecurity
Authors: Boykin Laura M. , Armstrong Karen F. , Kubatko Laura , De Barro Paul
Published: December 2011

Species delimitation directly impacts on global biosecurity. It is a critical element in the decisions made by national governments in regard to the flow of trade and to the biosecurity measures imposed to protect countries from the threat of invasive species. Here we outline a novel approach to species delimitation, “tip to root”, for two highly invasive insect pests, Bemisia tabaci (sweetpotato whitefly) and Lymantria dispar (Asian gypsy moth). Both species are of concern to biosecurity, but illustrate the extremes of phylogenetic resolution that present the most complex delimitation issues for biosecurity; B. tabaci having extremely high intra-specific genetic variability and L. dispar composed of relatively indistinct subspecies. This study tests a series of analytical options to determine their applicability as tools to provide more rigorous species delimitation measures and consequently more defensible species assignments and identification of unknowns for biosecurity. Data from established DNA barcode datasets (COI), which are becoming increasingly considered for adoption in biosecurity, were used here as an example. The analytical approaches included the commonly used Kimura two-parameter (K2P) inter-species distance plus four more stringent measures of taxon distinctiveness, (1) Rosenberg's reciprocal monophyly, (P(AB)), 1 (2) Rodrigo's (P(randomly distinct)), 2 (3) genealogical sorting index, ( gsi), 3 and (4) General mixed Yule- coalescent (GMYC). 4 , 5 For both insect datasets, a comparative analysis of the methods revealed that the K2P distance method does not capture the same level of species distinctiveness revealed by the other three measures; in B. tabaci there are more distinct groups than previously identified using the K2P distances and for L. dipsar far less variation is apparent within the predefined subspecies. A consensus for the results from P(AB), P(randomly distinct) and gsi offers greater statistical confidence as to where genetic limits might be drawn. In the species cases here, the results clearly indicate that there is a need for more gene sampling to substantiate either the new cohort of species indicated for B. tabaci or to detect the established subspecies taxonomy of L. dispar. Given the ease of use through the Geneious species delimitation plugins, similar analysis of such multi-gene datasets would be easily accommodated. Overall, the tip to root approach described here is recommended where careful consideration of species delimitation is required to support crucial biosecurity decisions based on accurate species identification.
Organizational Development of a University-Based Interdisciplinary Health Promotion Project
Authors: Weiss Joann R. , Wallerstein Nina , MacLean Thomas
Published: December 2011

Purpose.

To analyze the organizational development and implementation of an interdisciplinary health promotion project at the University of New Mexico. The effort involved three academic units in a 3-year externally funded project to institutionalize health promotion curricula in the respective schools and to develop a wellness-oriented service for students, faculty, and staff.

Methods.

The open systems theory was used as a framework to analyze the organizational and role issues that emerged from the data collected through interviews, staff surveys, and document review. The analysis is summarized by five thematic questions: (1) How did the project's vision affect its development? (2) How was leadership enacted, and with what effect? (3) What were the organizational issues for the staff? (4) What were the interdisciplinary dilemmas? (5) What was instituted or changed as a result of the project?

Results.

The analysis uncovered a series of interpersonal and organizational dilemmas involving the nature of the organizational environment, the character of interdisciplinary work, leadership, boundaries of group membership, and the structuring of a unified vision.

Conclusions.

Future projects should consider the strength and stability of the boundary spanners, the resource context, and the role of a unified vision for new and organizationally linked units as key issues in facilitating and sustaining change.
Occupational Stress, Physician-Excused Absences, and Absences Not Excused by a Physician
Authors: Heaney Catherine A. , Clemans Jill
Published: December 2011

Purpose.

This study explores two possible mechanisms through which occupational stress is linked to absenteeism. The extent to which physician-excused absenteeism and absenteeism not excused by a physician are related to employee reports of perceived stress is assessed.

Design.

A plantwide survey was conducted in January 1990. Employee reports of occupational stress gained from this survey were linked with 1990 absenteeism data from the employees' records.

Setting.

A mid-sized manufacturing plant.

Sample.

Complete data were available for 998 of the 1534 (65%) unionized employees in the plant.

Measures.

Measures of both physician-excused absences and absences not excused by a physician were created. Stressors included role ambiguity, lack of control over work pace, and being paid on a piece-rate basis. Perceived stresses included role conflict, physical environment stresses, and overall work stress.

Results.

For physician-excused absenteeism, role conflict (OR, 1.54, p <.01), overall work stress (OR 1.24, p <.05), and physical environment stress (OR 1.34, p <.05) had significantly elevated odds ratios, even after adjusting for demographics. For absences not excused by a physician, none of the stressors or stresses had significant odds ratios after controlling for demographic characteristics.

Conclusions.

Employees in this plant were not using short-term voluntary absenteeism as a way of coping with work stress. However, high levels of perceived work stress were associated with subsequent physician-excused absences.
Determinants of Intention to Adopt a Low-Fat Diet in Men 30 to 60 Years Old: Implications for Heart Health Promotion
Authors: Nguyen Minh Nguyet , Otis Joanne , Potvin Louise
Published: December 2011

Purpose.

The purpose of the study was to identify the determinants of intention to have a law-fat diet in 30- to 60-year-old men.

Design.

The survey design was cross-sectional and consisted of a self-administered questionnaire. The dependent variable was the intention to have a low-fat diet within the next 4 months, and the independent variables were those suggested by the theory of planned behavior.

Setting.

The study population was drawn from three districts representing a modal sample of Laval, the second most populous city (N = 314,398) in the province of Quebec.

Subjects.

The sample comprised 3200 people. Of the 3200 questionnaires sent out, 2583 were received and 2269 were eligible (i.e., were answered by 30- to 60-year-old men), giving a response rate of 70.9%. Of the 2269 questionnaires, 430 were incomplete, resulted in 1839 being usable for analysis.

Measures.

Multiple regression analysis was conducted to determine the influence of the independent variables on the dependent variable, the intention to have a low-fat diet. The independent variables were (1) direct and indirect determinants of intention as suggested in the theory of planned behavior and (2) sociodemographic and concomitant variables and their interactions. Discriminant analysis was used on the significant variables obtained in the regression to establish the cognitive profile of respondents' intention, strong or weak.

Results.

In the final model, five variables explained 51 % of the total variance. Respondents who had a stronger intention perceived that their important referents would approve them having a low-fat diet. They scored higher in seeing the advantages of adopting the target behavior and had a more positive attitude toward the behavior. They also perceived themselves as having control over the target behavior, and scored higher in terms of recognizing the perceived power of this control factor.

Conclusions.

The results suggest that the theory of planned behavior can be an effective tool in the planning of heart health promotion. They indicate that low-fat diet programs for men should target the work site and peer-group organizations, and place emphasis on adapting usual recipes. Though accenting the health and nutritional benefits of a low-fat diet, messages should appeal to emotion as well as reason.
The Effects of the Child and Adolescent Trial for Cardiovascular Health Intervention on Psychosocial Determinants of Cardiovascular Disease Risk Behavior among Third-Grade Students
Authors: Edmundson Elizabeth , Parcel Guy S. , Perry Cheryl L. , Feldman Henry A. , Smyth Mary , Johnson Carolyn C. , Layman Ann , Bachman Kathryn , Perkins Theresa , Smith Kevin , Stone Elaine
Published: December 2011

Purpose.

The Child and Adolescent Trial for Cardiovascular Health is a multi-site study of a school-based intervention designed to reduce or prevent the development of risk factors for cardiovascular disease. The goal was to change (or prevent) related risk behaviors and the psychosocial variables that theoretically influence those behaviors.

Design.

A nested design was used in which schools served as the primary unit of analysis. Twenty-four schools participated at each of four sites (Austin, San Diego, Minneapolis, and New Orleans). Each site had 10 control and 14 intervention schools.

Setting and Subject.

Ninety-six schools (with more than 6000 students) in the four sites were randomized to three treatment conditions: control, school-based interventions, and school-plus-family interventions. The sample included approximately equal numbers of males and females and was 67.5% white, 13.9% African-American, 13.9% Hispanic, and 4.7% other.

Measures.

The psychosocial determinants measured included improvements in dietary knowledge, intentions, self-efficacy, usual behavior, perceived social reinforcement for healthy food choices, and perceived reinforcement and self-efficacy for physical activity.

Results.

The findings indicated significant improvements in all the psychosocial determinants measured (p < .0001). The results revealed a greater impact in the school-plus-family intervention schools for two determinants, usual dietary behavior and intentions to eat heart-healthy foods.

Conclusions.

These findings support theory-based interventions for changing selected psychosocial determinants of cardiovascular disease risk behavior among children.
The Ecology of Urban Violence: Its Relationship to Health Promotion Behaviors in Low-Income Black and Latino Communities
Authors: Sanders-Phillips Kathy
Published: December 2011

Purpose.

The purpose of this review is to identify and examine relationships between exposure to violence and health promotion behaviors in low-income black and Latino groups.

Design.

Based on computer surveys of the psychologic, public health, medical, and sociologic literature, approximately 90 previous studies of the impact of exposure to violence on psychologic functioning, perceptions of health and well-being, and health decisions and behavior were identified. This article reviews those studies that examine the relationships between experiences of violence and subsequent feelings of alienation, powerlessness, and hopelessness, and perceptions of health and well-being and studies that examine relationships between alienation, hopelessness, and powerlessness and health promotion behaviors. Studies of health promotion behavior that did not examine or address the impact of exposure to violence are not reviewed in this article.

Results.

Violence affects low-income communities directly by contributing to rates of mortality, and indirectly by affecting health promotion behaviors. Exposure to violence can result in feelings of powerlessness, hopelessness, and alienation that significantly limit motivation, the extent of involvement, and persistence in overcoming barriers to health promotion behavior.

Conclusions.

Future researchers must consider the confounding effects of exposure to violence when investigating differences in health promotion behaviors for low-income black and Latino groups. Community empowerment programs that address the impact of violence and focus on developing control over life and health outcomes may be needed to successfully address the effect of violence on health promotion behavior in low-income, black and Latino communities.