bluuebunny/crossref_metadata_2025_split huggingface dataset:
Models for predicting friction coefficient and parameters with influence in elastohydrodynamic lubrication
Authors: Morgado P Lafont , Otero J Echávarri , Lejarraga J B Sánchez-Peñuela , Sanz J L Muñoz , Lantada A Díaz , Munoz-Guijosa J M , Yustos H Lorenzo , Wiña P Leal , García J Muñoz 
Published: April 2009

This article shows different friction prediction models applicable to lubricants in point contacts under an elastohydrodynamic regime. The types of models used are two variations of the Newtonian theory, the Limiting Shear Stress model and the one based on Carreau's equation. The article sets out the theoretical calculation procedures and the ensuing equations for calculating the friction coefficient. The aims of the article are to study the effect of the parameters with influence on friction and to compare the model's results with those given by an experimental stage performed on a mini traction machine. This test system allows the measurement of friction coefficient in point contacts (ball—disc) under a wide range of variation of parameters such as temperature, slide-roll ratio, lubricant, material, load, or velocity.
A Novel Approach to CFTR Mutation Testing by Pyrosequencing-Based Assay Panels Adapted to Ethnicities
Authors: Bickmann Julia K , Kamin Wolfgang , Wiebel Matthias , Häuser Friederike , Wenzel Jürgen J , Neukirch Carolin , Stuhrmann Manfred , Lackner Karl J , Rossmann Heidi 
Published: April 2009

Abstract
Background: Cystic fibrosis (CF) is a common autosomal recessive genetic disorder caused by a variety of sequence alterations in the CFTR gene [cystic fibrosis transmembrane conductance regulator (ATP-binding cassette sub-family C, member 7)]. Because the relative prevalence of mutations strongly depends on the ethnic background, first-level testing of CF as defined by recent consensus recommendations ought to be adaptable to the ethnicity of patients.
Methods: We therefore developed and implemented a diagnostic approach to first-level testing for CF based on published mutation frequencies and Pyrosequencing (PSQ) technology that we complemented with standard procedures of mutation detection at the second level.
Results: The current test system of PSQ assays for 46 target CF mutations [including CFTRdele2,3 (21 kb) and 1342-6 (T)n (5T/7T/9T)] permits recombinations of single assays to optimize sensitivities for certain ethnicities. By easy expansion of the original mutation panel, the first-level test sensitivities with other ethnic groups would be increased, provided that the mutation frequencies are known. The test was validated with our local, ethnically mixed, but mainly German population (155 patients). The mutation-detection rate for the 92 patients whose CF was confirmed by the sweat test was 89.0% for the patients of German descent (73 of the 92 patients) and 73.7% for the patients of any other origin (19 of the 92 patients). Ethnicity-adapted testing panels for our foreign CF patients would increase the sensitivities for the respective groups by approximately 5%.
Conclusions: PSQ-based genotyping is a reliable, convenient, highly flexible, and inexpensive alternative to conventional methods for first-level testing of CFTR, facilitating flexible adaptation of the analyzed mutation panel to any local ethnic group.
Measurement and Quality Control Issues in Multiplex Protein Assays: A Case Study
Authors: Ellington Allison A , Kullo Iftikhar J , Bailey Kent R , Klee George G 
Published: April 2009

Abstract
Background: Multiplex arrays are increasingly used for measuring protein biomarkers. Advantages of this approach include specimen conservation, limited sample handling, and decreased time and cost, but the challenges of optimizing assay format for each protein, selecting common dilution factors, and establishing robust quality control algorithms are substantial. Here, we use measurements of 15 protein biomarkers from a large study to illustrate processing, analytic, and quality control issues with multiplexed immunoassays.
Methods: We contracted with ThermoScientific for duplicate measurements of 15 proteins in 2322 participants from a community-based cohort, a plasma control, and recombinant protein controls using 2 custom planar microarrays with 6 (panel A) or 9 (panel B) capture antibodies printed in each well. We selected constituent analytes in each panel based on endogenous concentrations and assay availability. Protocols were standardized for sample processing, storage, and freeze-thaw exposures. We analyzed data for effects of deviations from processing protocols, precision, and bias.
Results: Measurements were within reportable ranges for each of the assays; however, concentrations for 7 of the 15 proteins were not centered on the dose–response curves. An additional freeze-thaw cycle and erroneous sample dilution for a subset of samples produced significantly different results. Measurements with large differences between duplicates were seen to cluster by analyte, plate, and participant. Conventional univariate quality control algorithms rejected many plates. Plate-specific medians of cohort and plasma control data significantly covaried, an observation important for development of alternative quality control algorithms.
Conclusions: Multiplex measurements present difficult challenges that require further analytical and statistical developments.
Developing Multiplexed Assays for Troponin I and Interleukin-33 in Plasma by Peptide Immunoaffinity Enrichment and Targeted Mass Spectrometry
Authors: Kuhn Eric , Addona Terri , Keshishian Hasmik , Burgess Michael , Mani D R , Lee Richard T , Sabatine Marc S , Gerszten Robert E , Carr Steven A 
Published: April 2009

Abstract
Background: Protein biomarker candidates from discovery proteomics must be quantitatively verified in patient samples before they can progress to clinical validation. Here we demonstrate that peptide immunoaffinity enrichment coupled with stable isotope dilution mass spectrometry (SISCAPA-MRM) can be used to configure assays with performance suitable for candidate biomarker verification. As proof of principle, we configured SISCAPA assays for troponin I (cTnI), an established biomarker of cardiac injury, and interleukin 33 (IL-33), an emerging immunological and cardiovascular marker for which robust immunoassays are currently not available.
Methods: We configured individual and multiplexed assays in which peptides were enriched from digested human plasma using antipeptide antibodies. Assay performance was established using response curves for peptides and proteins spiked into normal plasma. We quantified proteins using labeled peptides as internal standards, and we measured levels of cTnI in patients who underwent a planned myocardial infarction for hypertrophic obstructive cardiomyopathy.
Results: Measurement of cTnI and IL-33 proteins from trypsin-digested plasma was linear from 1.5 to 5000 μg/L, with imprecision &lt;13% for both proteins, processed individually or multiplexed. Results correlated well (R = 0.89) with a commercial immunoassay.
Conclusions: We used an established biomarker of cardiac injury and an emerging biomarker to demonstrate how SISCAPA can detect and quantify changes in concentration of proteins present at 1–10 μg/L in plasma. Our results demonstrate that these assays can be multiplexed and retain the necessary precision, reproducibility, and sensitivity to be applied to new and uncharacterized candidate biomarkers for verification of low-abundance proteins in blood. .
Parallel downregulation of retinol-binding protein-4 and adiponectin expression in subcutaneous adipose tissue of non-morbidly obese subjects
Authors: Broch Montserrat , Auguet Maria Teresa , Ramírez Rafael , Olona Montserrat , Aguilar Carmen , Megia Ana , Alcaide Maria José , Pastor Rosa , Martínez Salomé , Caubet Enric , Garcia-España Antonio , Richart Cristóbal 
Published: April 2009

Context and objectiveAdipokines are involved in the etiopathology of obesity-related disorders. Since the role of adipokine retinol-binding protein-4 (RBP4) in obesity remains uncertain and its relationship with other adipokines and inflammatory markers has not been examined in detail, we investigated the relationships of RBP4 mRNA expression and circulating protein levels with obesity, anthropometric and metabolic variables, as well as with obesity-related inflammatory markers adiponectin and C-reactive protein.Subjects and methodsOne-hundred and twenty-five subjects participated, 36 lean (body mass index (BMI): <25 kg/m2) and 89 obese (overweight/obese; BMI: ≥25<40) whose anthropometric and metabolic variables were assessed. mRNA expression was quantified by real-time PCR in subcutaneous adipose tissue (s.c.-AT) of 46 subjects.ResultsThere was a tendency for circulating RBP4 levels to positively correlate with waist circumference (β=0.29, P=0.08; R2=0.08), but there was no significant association with the obesity-related parameters analysed. RBP4 and adiponectin mRNA expression levels were similarly downregulated in the s.c.-AT of obese subjects (0.5-fold); however, RBP4 downregulation did not affect its circulating protein levels. The expression of RBP4 and adiponectin was positively correlated even after controlling for confounding factors (β=0.59, P<0.0001; R2=0.40).ConclusionsIn our population, RBP4 circulating levels were not significantly correlated with obesity-related parameters, although a tendency to correlate with waist circumference suggests a relationship with insulin resistance and other metabolic disorders. In addition, our results suggest that the production of RBP4 by other tissues such as liver, rather than s.c.-AT, may be involved in regulating RBP4 circulating levels.
Diagnosis and management of non‐anti‐D red cell antibodies in pregnancy
Authors: Gajjar Ketan , Spencer Chris 
Published: April 2009

Anti‐D prophylaxis has reduced the incidence of haemolytic disease of the newborn.
A variety of non‐anti‐D red cell antibodies can cause a degree of neonatal haemolysis.
The frequency of antibody testing should be individualised.
Management of non‐anti‐D alloimmunisation should be aimed at minimising perinatal morbidity.

Learning objectives:

To understand the causes and risk factors for maternal non‐anti‐D antibodies.
To learn when to initiate invasive testing in the antenatal period.
To know when to deliver the baby to maximise perinatal outcome.
To learn about which antibodies can cause fetal hydrops and intrauterine haemolysis.

Ethical issues:

When is it necessary to perform paternal blood tests to determine red cell antibody status?
When should the mother be delivered in cases where the red cell antibody detected has a weak association with neonatal haemolysis?

Please cite this article as: Gajjar K, Spencer C. Diagnosis and management of non‐anti‐D red cell antibodies in pregnancy. The Obstetrician & Gynaecologist 2009;11:89–95.
Primary and secondary cytomegalovirus in pregnancy
Authors: McCarthy Fergus P , Jones Cheryl , Rowlands Shelley , Giles Michelle 
Published: April 2009

Cytomegalovirus is the commonest cause of congenital viral infection in developed countries.
Infection is asymptomatic in 90% of individuals.
Forty percent of pregnant women with primary infection transmit it to their fetus.
Ten percent of infants with congenital cytomegalovirus display clinical manifestations at birth and are at risk of neurological sequelae.
While routine antenatal testing is not currently recommended, congenital infection remains a significant obstetric management problem.

Learning objectives:

To learn about the incidence, diagnosis and sequelae of cytomegalovirus in pregnancy.
To become familiar with treatment options for the management of congenital cytomegalovirus.

Ethical issues:

Should practitioners recommend routine cytomegalovirus screening in pregnancy?
Is a randomised controlled trial necessary before offering treatment with hyperimmune globulin for congenital cytomegalovirus?

Please cite this article as: McCarthy FP, Jones C, Rowlands S, Giles M. Primary and secondary cytomegalovirus in pregnancy. The Obstetrician & Gynaecologist 2009;11:96–100.
How to set up a perineal clinic
Authors: Fowler G , Williams A , Murphy G , Taylor K , Wood C , Adams E 
Published: April 2009

All women sustaining obstetric anal sphincter injury should be reviewed at 6–12 weeks postpartum.
All women with anal incontinence should be offered endoanal ultrasound, anorectal physiology testing and review by a clinician with experience in anal sphincter injury.
A perineal clinic provides the setting for debriefing and provision of consistent, accurate information from clinicians with a special interest in sphincter injury.

Learning objectives:

To be aware of the benefits of a perineal clinic.
To learn how to set up a perineal clinic.

Ethical issues:

Should anorectal testing be a routine part of the follow‐up of all women after anal sphincter injury or restricted to symptomatic women?
Who is responsible for debriefing women sustaining anal sphincter injury?

Please cite this article as: Fowler G, Williams A, Murphy G, Taylor K, Wood C, Adams E. How to set up a perineal clinic. The Obstetrician & Gynaecologist 2009;11:129–132.
Intra-articular Injected Synovial Stem Cells Differentiate into Meniscal Cells Directly and Promote Meniscal Regeneration Without Mobilization to Distant Organs in Rat Massive Meniscal Defect
Authors: Horie Masafumi , Sekiya Ichiro , Muneta Takeshi , Ichinose Shizuko , Matsumoto Kenji , Saito Hirohisa , Murakami Takashi , Kobayashi Eiji 
Published: April 2009

Abstract
Osteoarthritis in the knees, which can be caused by meniscal defect, constitutes an increasingly common medical problem. Repair for massive meniscal defect remains a challenge owing to a lack of cell kinetics for the menisci precursors in knee joint. The synovium plays pivotal roles during the natural course of meniscal healing and contains mesenchymal stem cells (MSCs) with high chondrogenic potential. Here, we investigated whether intra-articular injected synovium-MSCs enhanced meniscal regeneration in rat massive meniscal defect. To track the injected cells, we developed transgenic rats expressing dual luciferase (Luc) and LacZ. The cells derived from synovium of the rats demonstrated colony-forming ability and multipotentiality, both characteristics of MSCs. Hierarchical clustering analysis revealed that gene expression of meniscal cells was closer to that of synovium-MSCs than to that of bone marrow-MSCs. Two to 8 weeks after five million Luc/LacZ+ synovium-MSCs were injected into massive meniscectomized knee of wild-type rat, macroscopically, the menisci regenerated much better than it did in the control group. After 12 weeks, the regenerated menisci were LacZ positive, produced type 2 collagen, and showed meniscal features by transmission electron microscopy. In in-vivo luminescence analysis, photons increased in the meniscus-resected knee over a 3-day period, then decreased without detection in all other organs. LacZ gene derived from MSCs could not be detected in other organs except in synovium by real-time PCR. Synovium-MSCs injected into the massive meniscectomized knee adhered to the lesion, differentiated into meniscal cells directly, and promoted meniscal regeneration without mobilization to distant organs.
Disclosure of potential conflicts of interest is found at the end of this article.
Characterization of DLK1+ Cells Emerging During Skeletal Muscle Remodeling in Response to Myositis, Myopathies, and Acute Injury
Authors: Andersen Ditte C. , Petersson Stine J. , Jørgensen Louise H. , Bollen Peter , Jensen Pernille B. , Teisner Børge , Schroeder Henrik D. , Jensen Charlotte H. 
Published: April 2009

Abstract
Delta like 1 (DLK1) has been proposed to act as a regulator of cell fate determination and is linked to the development of various tissues including skeletal muscle. Herein we further investigated DLK1 expression during skeletal muscle remodeling. Although practically absent in normal adult muscle, DLK1 was upregulated in all human myopathies analyzed, including Duchenne- and Becker muscular dystrophies. Substantial numbers of DLK1+ satellite cells were observed in normal neonatal and Duchenne muscle, and furthermore, myogenic DLK1+ cells were identified during muscle regeneration in animal models in which the peak expression of Dlk1 mRNA and protein coincided with that of myoblast differentiation and fusion. In addition to perivascular DLK1+ cells, interstitial DLK1+ cells were numerous in regenerating muscle, and in agreement with colocalization studies of DLK1 and CD90/DDR2, qPCR of fluorescence-activated cell sorting DLK1+ and DLK1− cells revealed that the majority of DLK1+ cells isolated at day 7 of regeneration had a fibroblast-like phenotype. The existence of different DLK1+ populations was confirmed in cultures of primary derived myogenic cells, in which large flat nonmyogenic DLK1+ cells and small spindle-shaped cells coexpressing DLK1 and muscle-specific markers were observed. Myogenic differentiation was achieved when sorted DLK1+ cells were cocultured together with primary myoblasts revealing a myogenic potential that was 10% of the DLK1− population. Transplantation of DLK1+ cells into lacerated muscle did, however, not give rise to DLK1+ cell-derived myofibers. We suggest that the DLK1+ subpopulations identified herein each may contribute at different levels/time points to the processes involved in muscle development and remodeling.
Disclosure of potential conflicts of interest is found at the end of this article.
Sub-grain boundary mobilities during recovery of binary Al–Mn alloys
Authors: Barou Fabrice , Maurice Claire , Feppon Jean-Marie , Driver Julian 
Published: April 2009

Abstract
The influence of Mn solute atoms on sub-grain boundary mobilities in Al has been determined by accurate electron backscatter diffraction analysis of the sub-grain sizes and misorientations during recovery annealing. High purity Al-0.1 and 0.3 wt.% Mn alloys were deformed by plane strain compression at room temperature to equivalent strains of 1.8 and annealed in the temperature range 150 – 300 °C. An original method of image analysis on sub-boundaries from electron backscatter diffraction maps was applied to quantify the sub-grain size distributions. The change in average sub-grain size with time at several temperatures was then used to estimate sub-grain boundary mobilities in both Al – Mn alloys. The activation energies for sub-grain mobility were found to be 48 and 52 and kJ mol– 1 for the 0.1 and 0.3 % Mn alloys respectively, with the higher Mn alloy exhibiting lower rates. The sub-boundary mobilities are higher than expected from previous similar work on deformed Al – Si crystals. The orientation dependence of sub-grain growth is also examined.
Second-order faceting–roughening of the tilt grain boundary in zinc
Authors: Straumal Boris B. , Gornakova Alena S. , Sursaeva Vera G. , Yashnikov Viktor P. 
Published: April 2009

AbstractThe faceting of the almost stationary tilt grain boundary with a misorientation angle of 84° in the Zn bicrystal has been investigated. The shape of the very slow migrating grain boundary has been studied in situ between 350 and 400 °C using polarized light. Two intersecting facets lie in the closely-packed planes of the constrained coincidence sites lattice with coincidence parameter = 15. In the as-grown sample flat grain boundary facets form the sharp first-order ridge with the break of the first derivative y/x of the grain boundary shape similar to those observed in our previous works on GB faceting in Zn. However, above 350 °C the sharp first-order ridge is substituted by the smooth grain boundary portion without a ∂y/∂xderivative break similar to that observed in twin grain boundaries in Mo. The transformation of the as-grown first-order grain boundary ridge into continuous one has been observed for the first time. The critical parameter α has been calculated using the grain boundary shape in the transition region. α increases from α = 1.7 ± 0.07 for 350 °C to α = 1.9 ± 0.07 for 385 °C approaching the α = 2 value predicted in the mean-field Andreev model for the continuous surface roughening.
The combined effect of static recrystallization and twinning on texture in magnesium alloys AM30 and AZ31
Authors: Martin Étienne , Jiang Lan , Godet Stéphane , Jonas John J. 
Published: April 2009

Abstract
The potential for decreasing the texture intensity generated during the bulk deformation of Mg alloys was investigated using a combination of contraction twinning, double (secondary) twinning and static recrystallization. A large number of twins was induced by tensile deformation at room temperature. Their volume fraction and the variants selected during straining were found to be largely responsible for the changes evident in the deformation texture. Recrystallization of the twins generated a fine-grained microstructure, although no growth into the matrix grains was observed. In this way, annealing of the deformed samples did not lead to significant further texture changes.
Control of recrystallisation texture and texture-related properties in industrial production of aluminium sheet
Authors: Engler Olaf , Hirsch Jürgen 
Published: April 2009

Abstract
The principles of recrystallisation texture formation upon hot rolling and annealing of industrial aluminium alloy sheets are presented. It is demonstrated how texture control is applied during industrial processing of aluminium sheet so as to improve texture-related properties. This is illustrated by way of several examples, covering high-purity aluminium sheet for electrolytic capacitors, AlMnMg alloys for packaging and AlMgSi alloys for car body applications.
Early detection of crack initiation sites in TiAl alloys during low-cycle fatigue at high temperatures utilizing digital image correlation
Authors: Niendorf Thomas , Burs Christian , Canadinc Demircan , Maier Hans J. 
Published: April 2009

Abstract
Fatigue-induced damage accumulation was investigated in a third generation titanium aluminide alloy both at room temperature and at a temperature of 700 °C promoting oxidation. The digital image correlation technique was utilized for monitoring the evolution of local strain fields with cyclic deformation at both temperatures. With the aid of a newly adopted surface patterning technique, digital image correlation successfully detected the crack initiation sites prior to the actual formation of the cracks. Despite the oxidation at elevated temperatures, digital image correlation could detect the crack initiation sites at the early stages of the cyclic deformation, laying out the potential of this technique for monitoring the damage evolution in various metallic materials under severe service conditions.
On the solute-defect interaction in the framework of a defactant concept
Authors: Kirchheim Reiner 
Published: April 2009

Abstract
It will be shown that there is an analogy between surfactants in liquids which stabilize structures with large surface areas such as foams or microemulsions, and certain components in a crystalline solid, which stabilize defects such as grain boundaries and dislocations. These components are then called defactants. In the presence of defactants microstructural changes may occur because some of the defects compete more successfully for segregation of the defactants than others. Thus voids are formed at grain boundaries of Cu – Bi alloys because the formation energy of voids is provided by the interaction energy of Bi-atoms of the newly created surface. Or the beneficial role of rhenium on the high temperature creep of superalloys may be interpreted as a deficiency of defactants stabilizing dislocations and/or vacancies. These examples are discussed in the present work after a general treatment of the role of defactants.