bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Humidity on Friction of Carbon Nitride Coatings Under N2 Gas Lubrication
Authors: Adachi Koshi , Sodeyama Naoya , Kato Koji
Published: November 2008

The effect of humidity on friction properties of carbon nitride (CNx) in nitrogen (N2) atmosphere were investigated by using a ball-on-disk tribo-tester in atmospheres with controlled humidity and oxygen concentration. It was concluded that friction coefficient in the combination of CNx/CNx and Si3N4/CNx in N2 gas atmosphere were reduced from the order of 0.1 to 0.01 by decreasing of humidity from 40% RH to 0% RH when the O2 concentration is kept below 100 ppm. Further, stability of low friction of CNx/CNx in N2 gas atmosphere was confirmed experimentally. The frictional pair of CNx/CNx provided low and a stable friction coefficient of 0.01 in 99.9% nitrogen gas condition under low relative humidity of 2% or less.
Biomechanical Modeling of Hip Joint Prosthesis
Authors: Gaspar M. C. , Mateus A. , Pereira C. , Antunes F. V.
Published: November 2008

In this work a Bombelli cementless isoelastic RM total hip prosthesis was considered. It was implanted over a course of 14 years on the patient and studied subsequently to its chirurgical replacement. Computed Tomography, radiographies and 3-D laser scanning were used to assess the prosthesis geometry, while the original femur anatomy was modeled based on 2-D radiographies taken at different stages of the in-vivo implant of the prosthesis. A finite element model was developed, based on the generated 3-D geometrical model, considering a linear elastic behavior and typical loading conditions. This analysis allowed determining stress and strain fields throughout bone-prosthesis contact surface and critical areas in terms of micromovements. The developed procedure, consisting of 3-D scanning, generation of geometrical 3-D models and finite element analysis, results in a powerful tool to follow-up and predict failure mechanisms in hip joint prosthesis.
The Use of a Stress Rheometer in Lieu of Cone Penetration
Authors: Johnson Bryan
Published: November 2008

The Cone penetration test is used to provide a measurement of grease stiffness and is considered the most important of laboratory performed grease tests. The design of this test was intended to support new grease manufacture and sales. This test is not well suited for used grease as it requires a volume of grease which in most cases exceeds the volume of sample obtained from an in service field machine. The reporting method for cone penetration is very crude. The results are misleading in that the NLGI numbering system appears to be linear (0, 1, 2, 3 etc.) but the grease consistency changes are not linear. For example, one would reasonably think that NLGI 4 grease would be twice as stiff as an NLGI 2 and 4 times as stiff as an NLGI 1. Rheometer data is reported in Pa and these units avoid the awkwardness of the NLGI scale. When comparing this data to cone penetration, the non linear nature of the NLGI scale becomes apparent. A Good correlation was obtained between the test methods and it is concluded that use of a rheometer in lieu of cone penetration is both desirable and acceptable when monitoring the consistency of new grease or in service greases.
Wear Resistance of Smooth Automotive Cylinder Liner Surfaces
Authors: Anderberg C. , Johansson S. , Nilsson P. H. , Ohlsson R. , Rose´n B. G.
Published: November 2008

Demands for decreased environmental impact from vehicles are resulting in a strong push for decreased engine oil, fuel consumption and weight. New machining and coating technologies have offered ways to attack these problems. Engine oil and fuel consumption are to a great extent controlled by the topography of the cylinder liner surface and it is therefore important to optimise this surface. Recent engine tests have shown a reduction in oil consumption when using cylinder liners with a smoother finish than that given by the current plateau honing. However, engine manufacturers are hesitant to introduce smoother liner surfaces because of fears of severe wear and scuffing. There is also the possibility that smoother liner surfaces may be more sensitive to the choice of piston ring finishes. This paper therefore seeks to investigate the functional performance and resistance to wear of these smooth cylinder liners and the mating top ring surfaces.
A Comparative Study of Air-Coupled Ultrasound Sensor and Accelerometer in Detecting Bearing Defects
Authors: Dadouche A. , Safizadeh M. S. , Bird J. , Dmochowski W. , Forsyth D. S.
Published: November 2008

The aim of this preliminary study is to investigate the capabilities of a non-destructive evaluation (NDE) sensor in detecting bearing faults. An air-coupled ultrasound sensor is used for this purpose. An accelerometer, which is the standard sensor used in industry, is also used in order to compare the output spectrums of the two sensor signals. A defect was created intentionally on the bearing components to simulate a fatigue crack or other relevant defect. The power spectra of vibration signals measured by accelerometer and ultrasound sensor are compared and their advantages and disadvantages are determined.
The Role of Temperature and Substrate Pairing in the Tribochemistry of Phosphorus-Based Additives
Authors: Spencer N. D. , Heuberger R. , Antifakos J. , Rossi A.
Published: November 2008

The tribochemical mechanism of phosphorus-containing additives is important to understand, even if the ultimate aim is to replace them with something more environmentally benign. In a combinatorial experiment that explored a range of temperatures (RT-180°C), loads, two additives, and two substrate pairings, it was observed that zinc dialkyldithiophosphate (ZnDTP) reacted with steel surfaces to produce phosphate at room temperature, pyrophosphate at 130°C, and polyphosphate at 180°C. Metal-ceramic pairings did not seem to produce long-chain polyphosphates at 150°C. It was also observed that metal-metal pairings appear to benefit more from the presence of the additives than ceramic-metal pairings, which suggests that the role of the additives is largely to inhibit microwelding of the asperities across the sliding plane.
Tribology Testing of Advanced Aviation Oils, Bearing and Gear Materials
Authors: Wedeven L. D. , Black W. F. , Carlisle D. J.
Published: November 2008

Long standing demands of advanced gas turbine engine oils to operate with increasing temperatures have resulted in formulations with reduced boundary lubrication. The desire to introduce corrosion resistance bearing and gear steels with more chemically benign surfaces compared to conventional steels presents significant challenges for boundary lubrication. A scuffing load capacity test method highlights oil and bearing steel response to mixed-film lubrication and wear. Through traction measurements the test method differentiates additive type and concentration with respect to wear and scuffing performance. The introduction of stainless steels 440C and Pyrowear 675 significantly reduces scuffing performance compared to conventional M50 bearing steel. The scuffing load capacity screening tests with advanced additive candidates show feasibility to significantly increase tribology performance with stainless steels.
Random Surface Roughness Effects in Microasperity Lubrication
Authors: Vyas Prerit , Stephens Lyndon S.
Published: November 2008

It is well known that the classical theory of lubrication does not predict the existence of a stable hydrodynamic film between two parallel surfaces. Experimental results have shown that the surface roughness (asperities and cavities) helps the pressure buildup between the two surfaces, thus maintaining the load support that keeps the surfaces from collapsing into each other. The effect of surface roughness on lubrication has gained considerable attention since it is widely recognized that surface roughness can alter the solution for pressure and leakage in hydrodynamic bearings from that given by classical theory. The present work investigates the effect of random (stochastic) surface roughness on the lubrication characteristics of a thrust ring engineered with deterministic surface features.
Deposition and Measurement of Nanoscale Complex Hydrocarbon Films on Magnetic Hard Disk Surfaces
Authors: Gates Richard S. , Gunsel Selda , Hsu Stephen M.
Published: November 2008

Measurement of complex hydrocarbon film thickness on engineering surfaces such as magnetic hard disks is difficult if the film thickness is below the peak to valley distance of the surface roughness. Instrument sensitivity and detection accuracy for most of the common tools for this purpose is limited. We have developed a novel calibration technique that allows accurate measurement of such films within 5%–10% accuracy.
On the Tribological Effectiveness of Controlled Cutting Fluid Application in Machining With Coated Tools
Authors: Jayal Anshu D. , Balaji A. K.
Published: November 2008

Environmental and economic pressures are causing reevaluation of the use of Cutting Fluids (CFs) in machining operations, leading to recent efforts in promoting dry, as well as minimal quantity of lubricant (MQL), machining. This paper presents an experimental investigation into the effects of different CF application methods on various machining performance measures under modern cutting conditions using uncoated and coated cemented tungsten carbide tools. CF effects under dry, flood, and MQL conditions, were gauged through their influence on cutting forces, tool temperatures, tool-chip interfacial friction, and chip morphology during machining of AISI 1045 steel using commercially available uncoated, and mono- and multi-layer coated, carbide tools. The results show new trends on the individual cooling and lubricating effects of CF application methods, and the integrated effects of their interactions with tool material, on tribological performance.
Tribology of Coated Tools in High-Speed Machining: A Tool Wear and “Equivalent Toolface” Geometry Based Study
Authors: Balaji A. K.
Published: November 2008

Predicting tool-wear (and thereby, tool-life) and selecting proper coated tools along with appropriate tool geometry still remains a major concern for industries trying to achieve increased productivity using automated machining processes. This study is focused upon aggressive high-speed rough turning of AISI 1045 steel. The wear patterns in different coated tools (one mono-layer PVD and two multi-layer CVD coatings) are correlated to changes in nominal tool geometry. This study focuses on the role of tooling geometry (inclination and rake angles) and their importance in dictating the behavior, performance, and wear of coated tools. Using an ‘equivalent toolface’ (ET) model, this study correlates the nominal tool geometry to an equivalent geometry, thereby introducing a new methodology for characterizing the complex effects of multilayer coatings in terms of simple effective tool geometry. The ET approach provides a new angle for understanding the tribological effects of coatings in machining.
Self-Lubricating Cylinder Liner Coatings
Authors: Sutor Paul , Schwarz Ernest E.
Published: November 2008

In-cylinder wear and friction mitigation is essential for high-temperature, low-heat-rejection (LHR) engines. Under these extreme conditions, the piston ring/cylinder liner interface operates at oil-starved conditions. Surfaces Research has developed superior self-lubricating cylinder liner composite coatings containing novel solid lubricants to improve wear and friction under these conditions.
Vapor Deposition of Composite Organic-Inorganic Films
Authors: Kobrin B. , Chin J. , Ashurst W. R.
Published: November 2008

Results on the thermal and immersion stability of ultra-thin composite films created by a deposition method call MVD™ (Molecular Vapor Deposition [1]) are reported. It is observed that these composite films were denser and more stable in thermal and immersion applications when compared to traditional self-assembled monolayer (SAM) films. These improved films were created by a special “sequential” or “layered” deposition process sequence. The MVD™ composite coatings can be deposited at room temperature on a variety of materials such as polymers, fibers, metals, alloys and other materials which normally do not allow films to form with complete surface coverage.
A Simple Calculation of EHL Traction at Small Slide/Roll Ratio Including Roller Elasticity
Authors: Bair Scott , Kotzalas Michael
Published: November 2008

Elastohydrodynamic point contact traction may be predicted accurately for the small slide-to-roll ratio, Σ, isothermal case by first calculating the shear response of the liquid in a parallel gap with a hemispherical pressure distribution and then correcting Σ for the elastic roller compliance.
Vapor Phase Lubricant Adsorption on Magnetic Data Storage Media
Authors: Yun Yang , Gellman Andrew J.
Published: November 2008

Vapor phase lubrication (VPL) integrates media lubrication with the vacuum processing steps used throughout most of the hard disk media fabrication process. This avoids exposure of the unlubricated hydrogenated amorphous carbon (a-CHx) overcoat to the ambient air and airborne contamination. In vapor lubrication the a-CHx surface can be oxidized under controlled conditions immediately prior to lubricant adsorption. The interaction between lubricants and a-CHx films can be tailored by controlled oxidation of the a-CHx in vapor phase lubrication.
Development of a High Temperature Tribological Lubricant for Low Heat Rejection High Temperature Operation Diesel Engines
Authors: Saad Philipe , Kamo Lloyd , Mekari Milad , Bryzik Walter
Published: November 2008

Adiabatics INC. with the support of U.S. Army Tank Automotive and Armaments Command has developed a new high temperature lubricant with additives package to work under the rigid regime of advanced Low Heat Rejection (LHR) diesel engine operating parameters. Using the newly developed high temperature lubricant on a laboratory tribology test bench and on a single cylinder LHR engine, the Army specified requirements of 410 °C Top Ring Reversal (TRR), 175 °C sump temperatures, and friction coefficient of 0.085–0.10 have been met. We have used the test data generated from the laboratory tribology test bench, and the LHR single cylinder test engine to validate the eight tribology performance parameters. The eight tribology parameters are: Oil Film thickness, shear stress, shear rate, temperature, effective viscosity, wear, specific friction work, and contact stress. Also this paper includes test data for the newly designed lubricating and cooling system. Further testing will be conducted on a multi cylinder production engine to complete the validation process of the newly developed lubricant and the lubricating and cooling system.
Manufacturing Tribology in the Nano-Manufacturing Era
Authors: Marinescu Ioan
Published: November 2008

In 1966 a report published by UK Department of Education and Science introduced the concept of tribology, which was defined as the science of interacting surfaces in relative motion. Tribology in practice studies friction, wear and lubrication. These processes affect each other with interacting causes and effects: one aspect of tribology is the study of their interactions. One of the fields in which these interactions play a large effect is manufacturing in general and manufacturing processes in particular. From macro manufacturing processes (milling, turning, drilling, boring, etc) to micro (grinding, superfinishing) and nano manufacturing processes (polishing, lapping, CMP) friction, wear and lubrication are the main phenomena governing these processes. This paper will focus on micro and nano abrasive processes and emphasize the application of tribological knowledge on the outcomes of these processes. A study case regarding nano polishing of AlTiC magnetic head will be described together with a special tribo-technology, which will allow the generation of surfaces with Ry of 0.2 nanometers. Also molecular dynamics (MD) simulations of nanoindentation, nanoscratching and friction coefficient at the nano level will be presented.
Grease Performance in Tapered Roller Bearings
Authors: Hoeprich Michael R.
Published: November 2008

To gain insight into the physical aspects of grease lubrication, nine greases with different oil viscosity and thickener combinations were tested in a tapered rolling element bearing under a light thrust load at speeds of 1800 and 3600 RPM. Bearings were run for thirty days or until a 150°C rib temperature was reached. Using SEM analysis, thickener samples were taken after testing from the rib/roller and raceway contacts for comparison with the thickener in new grease. A post test infrared technique was also used to evaluate grease thickness at the rib/roller contact and was compared with calculated film thickness. Bearing operating temperatures were then compared with grease base oil viscosity and thickener type.
Wet Versus Dry Friction
Authors: Brochard-Wyart F. , Buguin A. , Clain J. , Ge´rardin H.
Published: November 2008

We study the dynamics of adhesion of soft objects (rubber bead, vesicles, living cells) on wet substrates by dewetting of the intercalated films, and the friction when the substrate moves at velocity U. Wetting transition are observed above a threshold velocity, leading to a lost of adhesion and a strong decrease of friction. It corresponds to the aquaplaning for cars (or people) stopping on a wet soil.
Development of a Numerical Simulation System to Evaluate Flying Characteristics of Head Sliders for Magnetic Disk Storage
Authors: Yoshida Hideyo , Hayashi Takefumi
Published: November 2008

In the present research, we developed an interactive numerical simulation system for evaluation of static and dynamic characteristics of a flying head slider under nano-meter spacing conditions. This system enables rapid and efficient calculation while changing parameters that affect the numerical solution of the fundamental equations. The system also supports several types of sliders and patterned disk surfaces as well. Furthermore, the upstream finite difference method is applied to the Couette flow term instead of the conventional central finite difference method, and the convergence of the pressure solution is found to be much improved.
Study of Small-Scale Friction at Elevated Temperatures
Authors: He Bo , Wang Q. Jane , Chung Yip-Wah
Published: November 2008

This paper presents some preliminary results obtained from small-scale friction measurements from 25°C to 200°C on fused silica and 1018 low carbon steel surfaces. Friction transition phenomena were observed on the surfaces of fused silica and 1018 low carbon steel. The friction coefficient of the fused silica was found to be lower at higher temperature due to the material softening effect. However, the friction coefficient of the 1018 steel was found to be greater at high temperature which is likely the result of surface oxide formation.
Nonhertzian Contact: Geometric and Computational Issues
Authors: Keer Leon M.
Published: November 2008

This talk will focus on some of the consequences that arise due to improvements that were made in such areas as surface characterization, materials development, power requirements and other technological advances, but primarily advances in computer hardware and software. These have led analysis from the arena of a closed-form solution of a single smooth contact (Hertz theory) to the semi-analytical analysis of rough contact, in which there may occur a large number of contacts due to the presence of many asperities. This paper will limit itself to the following aspects involved with contact that is not Hertzian: geometrical issues, friction, and finally, purely numerical issues that may relate to inelastic behavior. To illustrate how the development of high-speed computers enabled the solution of relatively complex problems, two specific examples are given. The first is the case of rough contact, which is solved by a combination of fast Fourier transform and some computer-enhanced methods. The second example is indentation of an inelastic body and calculation of residual stresses. Future research in contact mechanics will involve calculations at even smaller length scales that depend upon the ever-increasing computational speed and development of sensors to investigate materials at these scales.
Direct Mechanical Measurement of Organised Water and the Influence of Adjacent Surface Chemistry Using Atomic Force Microscopy (Keynote)
Authors: Higgins M. J. , Polcik M. , Fukuma T. , Sader J. E. , Jarvis S. P.
Published: November 2008

Directly measuring structural changes in water with a mechanical probe of lateral dimensions comparable to that of a single molecule provides an invaluable insight into how and why bio-molecules behave with high selectivity or why certain surfaces promote or inhibit bio-molecular adhesion. In the immediate vicinity of the molecule, continuum models break down and the aqueous environment will often form a discrete layered structure depending on the nature of the molecule. The absence or presence of such structure may be fundamental in influencing the promotion or inhibition of protein adsorption, biological function and membrane recognition.
Decoupling Adjustment of Crown and Camber for Flying Height Control
Authors: Zhang Mingsheng , Liu Jin , Gonzaga Leonard , Liu Bo
Published: November 2008

An active slider with an H-shaped PZT and a U-shaped or grooved slider body is proposed for flying height control. The active slider has a decoupled crown and camber adjustment to improve the flying height adjustment ability. It can achieve more than 2nm flying height adjustment with a 12V voltage input.
New Bench Test to Study Mild Lubricated Wear
Authors: Fan J. Y. , Spikes Hugh A.
Published: November 2008

This extended abstract describes a new bench test for measuring and studying mild, lubricated wear. The method combines MTM, which is able to produce contra-rotation so as to obtain high sliding speed while retaining low entrainment speed and thus boundary lubrication conditions, with ICP which is employed to analyze trace levels of iron in lubricants so as to monitor mild wear throughout a test.
Tribochemistry of Materials
Authors: Hsu Stephen M.
Published: November 2008

Tribochemistry refers to the contact chemistry occurs inside the wearing interface under boundary lubricated conditions. Since lubrication chemistry has been dominated by hydrocarbon-steel chemistry, other chemistry between insulators, semiconductors, carbon films and lubricants has not been explored extensively. As new materials continue to evolve spurred by increasingly sophisticated means to control atoms, molecules, and microstructures, how to lubricate these new materials has become an important technological barrier for materials utilization and new technology development. This paper addresses the basic known information of tribochemistry with materials and describes the various measurement techniques that can be used to understand tribochemistry with various classes of materials.
Brownian Motion of Solids (or Drops) on a Vibrated Plate, Including Dry Friction
Authors: de Gennes P.-G.
Published: November 2008

We all know that dry friction of a solid on a solid was studied first by L. da Vinci, and that his results were rediscovered by Amontons. The basic laws have been understood — in terms of rubbing asperities — in the 20th century, mainly thanks to the British school [1]. When an object lies on a horizontal plate, it does not start to move until the horizontal force f reaches a certain threshold. For macroscopic objects, the threshold is proportional to the weight of the object. For mesoscopic objects (of micrometer size), the same sort of threshold may still exist, provided that the solid/solid contact involves a large number of asperities.
Low Friction Achieved Using Repulsive Van Der Waals Forces: A Nanotribology Study With Colloid Probe AFM
Authors: Feiler A. A. , Bergstro¨m L. , Rutland M. W.
Published: November 2008

We show that extremely low friction can be achieved with the use of a divergent, pre-contact “surface force” — the repulsive, so called van der Waals force. In almost all cases this force is attractive, but for certain combinations of materials it manifests repulsively and at short separations (of the order of molecular distances) the load bearing capacity provided by the force is large. We have used the Atomic Force Microscope (AFM) in colloid probe mode to measure the friction between sub-microscopic contacts in the presence of such a force and have achieved a friction coefficient of the order of 0.0002.
The Psychology of Transcending the Here and Now
Authors: Liberman Nira , Trope Yaacov
Published: November 2008

People directly experience only themselves here and now but often consider, evaluate, and plan situations that are removed in time or space, that pertain to others' experiences, and that are hypothetical rather than real. People thus transcend the present and mentally traverse temporal distance, spatial distance, social distance, and hypotheticality. We argue that this is made possible by the human capacity for abstract processing of information. We review research showing that there is considerable similarity in the way people mentally traverse different distances, that the process of abstraction underlies traversing different distances, and that this process guides the way people predict, evaluate, and plan near and distant situations.
Ab Initio Determination of Light Hadron Masses
Authors: Dürr S. , Fodor Z. , Frison J. , Hoelbling C. , Hoffmann R. , Katz S. D. , Krieg S. , Kurth T. , Lellouch L. , Lippert T. , Szabo K. K. , Vulvert G.
Published: November 2008

More than 99% of the mass of the visible universe is made up of protons and neutrons. Both particles are much heavier than their quark and gluon constituents, and the Standard Model of particle physics should explain this difference. We present a full ab initio calculation of the masses of protons, neutrons, and other light hadrons, using lattice quantum chromodynamics. Pion masses down to 190 mega–electron volts are used to extrapolate to the physical point, with lattice sizes of approximately four times the inverse pion mass. Three lattice spacings are used for a continuum extrapolation. Our results completely agree with experimental observations and represent a quantitative confirmation of this aspect of the Standard Model with fully controlled uncertainties.
Regulation of Pancreatic β Cell Mass by Neuronal Signals from the Liver
Authors: Imai Junta , Katagiri Hideki , Yamada Tetsuya , Ishigaki Yasushi , Suzuki Toshinobu , Kudo Hirohito , Uno Kenji , Hasegawa Yutaka , Gao Junhong , Kaneko Keizo , Ishihara Hisamitsu , Niijima Akira , Nakazato Masamitsu , Asano Tomoichiro , Minokoshi Yasuhiko , Oka Yoshitomo
Published: November 2008

Metabolic regulation in mammals requires communication between multiple organs and tissues. The rise in the incidence of obesity and associated metabolic disorders, including type 2 diabetes, has renewed interest in interorgan communication. We used mouse models to explore the mechanism whereby obesity enhances pancreatic β cell mass, pathophysiological compensation for insulin resistance. We found that hepatic activation of extracellular regulated kinase (ERK) signaling induced pancreatic β cell proliferation through a neuronal-mediated relay of metabolic signals. This metabolic relay from the liver to the pancreas is involved in obesity-induced islet expansion. In mouse models of insulin-deficient diabetes, liver-selective activation of ERK signaling increased β cell mass and normalized serum glucose levels. Thus, interorgan metabolic relay systems may serve as valuable targets in regenerative treatments for diabetes.
Who Scientists Are Now
Authors: Gieryn Thomas F.
Published: November 2008

The Scientific Life
. A Moral History of a Late Modern Vocation.
By Steven Shapin
. University of Chicago Press, Chicago, 2008. 486 pp. $29, £15. ISBN 9780226750248.

Shapin's account of the development and current practice of the profession of science spotlights the researchers in the trenches rather than the big thinkers.
Cross-Reactivity of
Paracoccidioides brasiliensis
,
Histoplasma capsulatum
, and
Cryptococcus
Species in the Commercial Platelia
Aspergillus
Enzyme Immunoassay
Authors: Xavier Melissa O. , Pasqualotto Alessandro C. , Cardoso Isabel Cristina E. , Severo Luiz Carlos
Published: November 2008

Cross-reactivity in the Platelia
Aspergillus
enzyme immunoassay was evaluated using 120 sera from patients with paracoccidioidomycosis, histoplasmosis, and cryptococcosis. At a cutoff value of 0.5, positivity rates were 50%, 67%, and 50%, respectively. The implications for these findings are discussed.
RelB Sustains IκBα Expression during Endotoxin Tolerance
Authors: Chen Xiaoping , Yoza Barbara K. , El Gazzar Mohamed , Hu Jean Y. Q. , Cousart Sue L. , McCall Charles E.
Published: November 2008

Transcription factors and chromatin structural modifiers induce clinically relevant epigenetic modifications of blood leukocytes during severe systemic inflammation (SSI) in humans and animals. These changes affect genes with distinct functions, as exemplified by the silencing of a set of acute proinflammatory genes and the sustained expression of a group of antimicrobial and anti-inflammatory genes. This paradigm is closely mimicked in the THP-1 human promonocyte cell model of lipopolysaccharide (LPS) endotoxin tolerance. We previously reported that LPS-induced de novo expression of RelB is required for generating tolerance to interleukin-1β (IL-1β) and tumor necrosis factor alpha (TNF-α) expression. RelB represses transcription by binding with heterochromatic protein 1 α (HP1α) to the proximal promoters of IL-1β and TNF-α. In contrast, we report herein that RelB is required for sustained expression of anti-inflammatory IκBα in LPS-tolerant THP-1 cells. RelB transcription activation requires binding to the IκBα proximal promoter along with NF-κB p50 and is associated with an apparent dimer exchange with p65. We also observed that RelB induced during human SSI binds to the IκBα proximal promoter of circulating leukocytes. We conclude that RelB functions as a dual transcription regulator during LPS tolerance and human SSI by activating and repressing innate immunity genes.
Comparison of a Multiplexed Herpes Simplex Virus Type-Specific Immunoglobulin G Serology Assay to Immunoblot, Western Blot, and Enzyme-Linked Immunosorbent Assays
Authors: Martins Thomas B. , Welch Ryan J. , Hill Harry R. , Litwin Christine M.
Published: November 2008

The human herpes simplex virus (HSV) is highly pathogenic, with infections caused by two distinct antigenic types, HSV-1 and HSV-2. Differentiation of antibodies to these specific antigens can provide useful information for the diagnosis of subclinical or undiagnosed HSV-2 infections, as well as for reducing the risk of maternal transfer of HSV to the neonate. In this study, a multiplex assay capable of concurrent detection of HSV-1 and -2 immunoglobulin G (IgG) antibodies was compared to immunoblot, Western blot, and enzyme-linked immunosorbent assays. Agreement of the multiplex assay was 95% or greater (
n
= 332) for both HSV-1 and -2 compared to the three assays. Sensitivities for HSV-1 ranged from 94.9 to 97.9%, with specificities of 93 to 97%. For HSV-2, the sensitivity and specificity ranges were 92.6 to 98.9% and 98.3 to 98.7%, respectively. Our studies show that the multiplexed microsphere-based assay offers a sensitive and specific alternative method for the detection HSV-1 and -2 type-specific antibodies. Advantages of the multiplex assay include multiple results per assay, the inclusion of internal controls for each specimen, and higher throughput of results.
Lymphoproliferative and Cytokine Responses to
Cryptosporidium parvum
in Patients Coinfected with
C. parvum
and Human Immunodeficiency Virus
Authors: Kaushik Kirti , Khurana Sumeeta , Wanchu Ajay , Malla Nancy
Published: November 2008

We compared the lymphoproliferative and cytokine responses to
Cryptosporidium parvum
in human immunodeficiency virus (HIV)-seropositive and -seronegative patients. The lymphoproliferative and cytokine responses (interleukin-2 [IL-2], IL-4, IL-5, IL-10, gamma interferon, and tumor necrosis factor alpha) were assessed for 11 HIV-seropositive,
Cryptosporidium
-positive (group I) patients; 20 HIV-seropositive,
Cryptosporidium
-negative (group II) patients; 10 HIV-seronegative,
Cryptosporidium
-positive (group III) patients, including four post-renal transplant (group IIIa) and 6 presumably immunocompetent (group IIIb) patients; and 20 HIV-seronegative,
Cryptosporidium
-negative healthy individuals (group IV). No significant difference was observed in the number of patients showing positive lymphoproliferative responses in group I compared to group III (post-renal transplant [group IIIa] or immunocompetent [group IIIb]) patients, while a comparison of the median stimulation indices shows that responses were significantly lower in
Cryptosporidium
-infected, immunosuppressed (group I and IIIa) patients than in immunocompetent (group IIIb) patients. The number of patients showing positive responses and median stimulation indices was significantly higher for
Cryptosporidium
-infected (HIV-seropositive and -seronegative) individuals than for uninfected individuals, suggesting that
Cryptosporidium
induces significant in vitro lymphoproliferative responses in infected individuals. Cytokine levels, except for that of IL-5, were significantly higher in
Cryptosporidium
-infected (groups I and III) individuals than in uninfected (groups II and IV) individuals. There was no significant difference between the group I and III patients and between
Cryptosporidium
-infected immunosuppressed (group I or IIIa) and immunocompetent (group IIIb) patients.
First Case of
Mycobacterium heckeshornense
Lymphadenitis
Authors: McBride Stephen J. , Taylor Susan L. , Pandey Sushil K. , Holland David J.
Published: November 2008

Mycobacterium heckeshornense
is a slow-growing nontuberculous mycobacterium first characterized in 2000. It is reported to cause lung disease and tenosynovitis. We report a case of isolated massive axillary lymphadenopathy in an elderly woman, where histology showed necrotizing granulomata and
M
.
heckeshornense
was isolated as the causative organism.
Results of Use of WHO Global Salm-Surv External Quality Assurance System for Antimicrobial Susceptibility Testing of
Salmonella
Isolates from 2000 to 2007
Authors: Hendriksen Rene S. , Seyfarth Anne Mette , Jensen Arne B. , Whichard Jean , Karlsmose Susanne , Joyce Kevin , Mikoleit Matthew , Delong Stephanie M. , Weill François-Xavier , Aidara-Kane Awa , Lo Fo Wong Danilo M. A. , Angulo Frederick J. , Wegener Henrik C. , Aarestrup Frank M.
Published: November 2008

An international External Quality Assurance System (EQAS) for antimicrobial susceptibility testing of
Salmonella
was initiated in 2000 by the World Health Organization (WHO) Global Salm-Surv in order to enhance the capacities of national reference laboratories to obtain reliable data for surveillance purposes worldwide. Seven EQAS iterations have been conducted from 2000 to 2007. In each iteration, participating laboratories submitted susceptibility results from 10 to 15 antimicrobial agents for eight
Salmonella
isolates and an
Escherichia coli
reference strain (ATCC 25922). A total of 287 laboratories in 102 countries participated in at least one EQAS iteration. A large number of laboratories reported results for the
E. coli
ATCC 25922 reference strain which were outside the quality control ranges. Critical deviations for susceptibility testing of the
Salmonella
isolates varied from 4% in 2000 to 3% in 2007. Consistent difficulties were observed in susceptibility testing of amoxicillin-clavulanic acid, cefotaxime, ceftazidime, streptomycin, sulfonamides, and tetracycline. Regional variations in performance were observed, with laboratories in central Asia, Africa, and the Middle East not performing as well as those in other regions. Results from the WHO Global Salm-Surv EQAS show that most laboratories worldwide are capable of correctly performing antimicrobial susceptibility testing of
Salmonella
isolates, but they also indicate that further improvement for some laboratories is needed. In particular, further training and dissemination of information on quality control, appropriate interpretive criteria (breakpoints), and harmonization of the methodology worldwide through WHO Global Salm-Surv and other programs will contribute to the generation of comparable and reliable antimicrobial susceptibility data (D. M. A. Lo Fo Wong, R. S. Hendriksen, D. J. Mevius, K. T. Veldman, and F. M. Aarestrup, Vet. Microbiol. 115:128-139, 2006).
Association of Diarrheagenic
Escherichia coli
Pathotypes with Infection and Diarrhea among Mexican Children and Association of Atypical Enteropathogenic
E. coli
with Acute Diarrhea
Authors: Estrada-Garcia Teresa , Lopez-Saucedo Catalina , Thompson-Bonilla Rocio , Abonce Maricela , Lopez-Hernandez Daniel , Santos Jose Ignacio , Rosado Jorge L. , DuPont Herbert L. , Long Kurt Z.
Published: November 2008

Seventy-six children ≤2 years old were prospectively followed for 1 year in a peri-urban community of Mexico City to determine asymptomatic infection and acute diarrhea associated with diarrheagenic
Escherichia coli
pathotypes (DEPs). By use of a pathogen-specific multiplex PCR, DEPs were sought in 795 stool samples, of which 125 (16%) were positive for DEP; of these, 4 represented shedding episodes and 4 parasite coinfections. Most single-DEP infections (85/117) were asymptomatic (
P
< 0.001), and of the 32 DEP diarrhea episodes, 41% were associated with atypical enteropathogenic
E. coli
(aEPEC), 37.5% with enterotoxigenic
E. coli
, 9% with typical EPEC, 9% with enteroinvasive
E. coli
, and 3% with Shiga toxin-producing
E. coli
strains. Among the 76 children, 54 had at least one stool positive for DEP, of which 23 experienced a DEP-associated diarrhea episode. In the last group of children, DEP infection was significantly associated with a diarrhea episode (relative risk [RR] = 2.5; 95% confidence interval [CI], 1.79 to 3.57;
P
< 0.001), with ETEC (RR = 2.30; 95% CI, 1.49 to 3.54;
P
= 0.003) and aEPEC (RR = 1.92; 95% CI, 1.23 to 3.0;
P
= 0.019) being the pathotypes associated with diarrhea. aEPEC-associated diarrhea episodes were frequently in the <12-month age group (RR = 2.57; 95% CI, 1.05 to 6.27;
P
= 0.04). aEPEC infections were distributed all year round, but associated diarrheal episodes were identified from April to October, with a May-June peak (rainy season). Most ETEC infections and diarrhea episodes characteristically occurred during the summer (rainy season), with a diarrhea peak in August. Of all DEPs, only aEPEC was associated with acute diarrhea episodes lasting 7 to 12 days (
P
= 0.019). DEPs are important causes of community-acquired enteric infection and diarrhea in Mexican children.
“
Mycobacterium canettii
” Isolated from a Human Immunodeficiency Virus-Positive Patient: First Case Recognized in the United States
Authors: Somoskovi Akos , Dormandy Jillian , Mayrer Andrew R. , Carter Martin , Hooper Nancy , Salfinger Max
Published: November 2008

We report the first case of tuberculosis caused by “
Mycobacterium canettii
” recognized in the United States. The pathogen was isolated from the cerebrospinal fluid of a 30-year-old Sudanese refugee.
Mycoplasma agalactiae p40
Gene, a Novel Marker for Diagnosis of Contagious Agalactia in Sheep by Real-Time PCR: Assessment of Analytical Performance and In-House Validation Using Naturally Contaminated Milk Samples
Authors: Oravcová Katarína , López-Enríquez Lorena , Rodríguez-Lázaro David , Hernández Marta
Published: November 2008

We evaluated the capacity of the
Mycoplasma agalactiae p40
gene as a diagnostic marker for contagious agalactia in sheep by quantitative real-time PCR. The
p40
gene encodes an immunodominant adhesin that plays a key role in cytoadhesion of
M. agalactiae
. The assay was 100% specific, with an analytical sensitivity of 1 genome equivalent (GE), a quantification that is highly linear (
R
2
> 0.992) and efficient (PCR efficiency, >0.992) over a 6-log dynamic range, down to 10 GE. We evaluated the capacity of the assay to detect
Mycoplasma agalactiae
in 797 milk samples (373 raw sheep milk samples from refrigerated tanks of different farms and 424 milk samples from individual sheep of a flock positive for
M. agalactiae
). In parallel, we also tested the samples by using microbiological isolation coupled with microscopy identification and by a PCR method recommended by the World Organization for Animal Health. While our assay was able to detect 57 (15.28%) positive samples of the 373 milk samples from different farms, identification by microbiological isolation coupled with microscopy detected only 36 (9.65%) samples, and the conventional PCR detected 31 (8.31%) samples. These findings showed that our assay based on the
p40
gene is more specific and sensitive for the detection of
M. agalactiae
in actual natural samples and, thus, can be a promising alternative tool for diagnosis and epidemiological studies of
M. agalactiae
infection.
Association of Nonsynonymous Substitutions in the Intermediate Region of the
vacA
Gene of
Helicobacter pylori
with Gastric Diseases in Taiwan
Authors: Sheu Shew-Meei , Hung Kuei-Hsiang , Sheu Bor-Shyang , Yang Hsiao-Bai , Wu Jiunn-Jong
Published: November 2008

The amino acid sequences corresponding to the
vacA
intermediate region from 39 isolates of
Helicobacter pylori
were investigated. The substitution of a G for the third S in the i1-type cluster B sequence (QASEGITS
S
K) conferred a greater risk of gastric diseases (
P
< 0.03; Fisher's exact test). The conserved substitutions of an F for the Y in the cluster A sequence and of an M for the second N in the i1-type cluster C sequence could be a marker of VacA in the Taiwanese strains.
Detection of Multiple Pathogenic Species in Saliva Is Associated with Periodontal Infection in Adults
Authors: Paju Susanna , Pussinen Pirkko J. , Suominen-Taipale Liisa , Hyvönen Mari , Knuuttila Matti , Könönen Eija
Published: November 2008

We investigated whether certain bacterial species and their combinations in saliva can be used as markers for periodontitis. In 1,198 subjects, the detection of multiple species, rather than the presence of a certain pathogen, in saliva was associated with periodontitis as determined by the number of teeth with deepened periodontal pockets.
Gardnerella vaginalis
Acute Hip Arthritis in a Renal Transplant Recipient
Authors: Sivadon-Tardy Valérie , Roux Anne-Laure , Piriou Philippe , Herrmann Jean-Louis , Gaillard Jean-Louis , Rottman Martin
Published: November 2008

We report the case of an acute hip septic arthritis caused by
Gardnerella vaginalis
in a 48-year-old woman under immunosuppressive therapy for kidney transplantation. After surgical resection of the hip and 6 weeks of combination antibiotic therapy, a total hip prosthesis was successfully implanted with no recurrence after 4 years.
Phenotypic and Genotypic Characterization of
Arcanobacterium haemolyticum
Isolates from Infections of Horses
Authors: Hassan Abdulwahed Ahmed , Ülbegi-Mohyla Hivda , Kanbar Talah , Alber Jörg , Lämmler Christoph , Abdulmawjood Amir , Zschöck Michael , Weiss Reinhard
Published: November 2008

The present study was designed to characterize phenotypically and genotypically seven
Arcanobacterium haemolyticum
strains obtained from infections of six horses. All seven strains showed the cultural and biochemical properties typical of
A. haemolyticum
and were susceptible to most of the antibiotics tested. The species identification could be confirmed by amplification and sequencing of the 16S rRNA gene and the 16S-23S rRNA intergenic spacer region and by PCR amplification of species-specific parts of the gene encoding phospholipase D in
A. haemolyticum
. Use of the latter could possibly improve future identification of this generally human pathogenic bacterial species which, according to the present results, seems to occur also in infections of horses.
SOCS-1 Mimetics Protect Mice against Lethal Poxvirus Infection: Identification of a Novel Endogenous Antiviral System
Authors: Ahmed Chulbul M. , Dabelic Rea , Waiboci Lilian W. , Jager Lindsey D. , Heron Linda L. , Johnson Howard M.
Published: November 2008

The suppressor of cytokine signaling 1 (SOCS-1) protein modulates cytokine signaling by binding to and inhibiting the function of Janus kinases (JAKs), ErbB, and other tyrosine kinases. We have developed a small tyrosine kinase inhibitor peptide (Tkip) that binds to the autophosphorylation site of tyrosine kinases and inhibits activation of STAT transcription factors. We have also shown that a peptide corresponding to the kinase-inhibitory region of SOCS-1, SOCS1-KIR, similarly interacts with the activation loop of JAK2 and blocks STAT activation. Poxviruses activate cellular tyrosine kinases, such as ErbB-1 and JAK2, in the infection of cells. We used the pathogenesis of vaccinia virus in C57BL/6 mice to determine the ability of the SOCS-1 mimetics to protect mice against lethal vaccinia virus infection. Injection of mice intraperitoneally with Tkip or SOCS1-KIR containing a palmitate for cell penetration, before and at the time of intranasal challenge with 2 × 10
6
PFU of vaccinia virus, resulted in complete protection at 100 μg. Initiation of treatment 1 day postinfection resulted in 80% survival. Administration of SOCS-1 mimetics by the oral route also protected mice against lethal effects of the virus. Both SOCS1-KIR and Tkip inhibited vaccinia virus transcription and replication at early and possibly later stages of infection. Vaccinia virus-induced phosphorylation of ErbB-1 and JAK2 was inhibited by the mimetics. Protected mice mounted a strong humoral and cellular response to vaccinia virus. The use of SOCS-1 mimetics in the treatment of poxvirus infections reveals an endogenous regulatory system that previously was not known to have an antiviral function.
Nuclear Factor-κB Binds to the Epstein-Barr Virus LMP1 Promoter and Upregulates Its Expression
Authors: Johansson Pegah , Jansson Ann , Rüetschi Ulla , Rymo Lars
Published: November 2008

The latent membrane protein 1 (LMP1) oncogene carried by Epstein-Barr virus (EBV) is essential for transformation and maintenance of EBV-immortalized B cells in vitro, and it is expressed in most EBV-associated tumor types. The activation of the NF-κB pathway by LMP1 plays a critical role in the upregulation of antiapoptotic proteins. The EBV-encoded EBNA2 transactivator is required for LMP1 activation in latency III, while LMP1 itself appears to be critical for its activation in the latency II gene expression program. In both cases, additional viral and cellular transcription factors are required in mediating transcription activation of the LMP1 promoter. Using DNA affinity purification and chromatin immunoprecipitation assay, we showed here that members of the NF-κB transcription factor family bound to the LMP1 promoter in vitro and in vivo. Electrophoretic mobility shift assay analyses indicated the binding of the p50-p50 homodimer and the p65-p50 heterodimer to an NF-κB site in the LMP1 promoter. Transient transfections and reporter assays showed that the LMP1 promoter is activated by exogenous expression of NF-κB factors in both B cells and epithelial cells. Exogenous expression of NF-κB factors in the EBNA2-deficient P3HR1 cell line induced LMP1 protein expression. Overall, our data are consistent with the presence of a positive regulatory circuit between NF-κB activation and LMP1 expression.