bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mean Compressive Stresses - Experimental and Theoretical Investigations Into Their Influence on the Fatigue Strength of Welded Structures
Authors: Rörup J 
Published: October 2005

To indicate the effect of mean compressive stresses on the structural durability, fatigue tests have been carried out under constant-amplitude load. As a particularly suitable design detail, the longitudinal stiffener with non-load-carrying fillet welds was selected. This detail represents the permissible limit of notch condition in highly stressed ship structures. The fillet weld was made with two layers, so that a fully developed residual stress field could be expected. In order to gain more insight into the technical background under consideration of the weld-induced residual stresses and their redistribution during cyclic loading, finite element analyses as well as measurements were carried out. On uncracked specimens the weld-induced residual stresses were measured using the X-ray method. The redistribution of the residual stresses during crack propagation was measured using the neutron diffraction method. Different models were used for the numerical simulation using the finite element (FE) method. In the first phase the FE calculation could be limited on a linear analysis, because the semielliptical crack propagating through the plate thickness remained open over the full cycles, which is due to the high residual stresses. After the crack became a through-thickness crack, closure effects became significant, requiring a non-linear crack propagation analysis with a shell model. Therefore the weld-induced residual stresses must be reproduced with a solid model and transmitted to the shell model. Taking into account the complete crack length during the simulation, it was possible to estimate the fatigue life under constant amplitude loads in a satisfactory way.
The modelling of residual stresses due to surface peening using eigenstrain distributions
Authors: Korsunsky A. M 
Published: October 2005

The beneficial effect of surface peening (including shot peening, laser shock peening, low plasticity burnishing, etc.) on fatigue resistance of structural alloys is well documented and widely used in industry to improve component life. It is perhaps the most widely used technique that relies on the introduction of residual stresses into the component by direct mechanical means. The resulting stress states are usually evaluated experimentally by X-ray diffraction or other stress measurement techniques. In order for shot peening operations to be effective and reliable, the process of introducing residual stresses and strains into peened components must not only be controlled but also be predictable and quantifiable. The present paper establishes a framework for predictive modelling of the residual stress states due to surface peening. Firstly, uniform (within planes parallel to the surface) plastic deformation of the surface layer taking place during shot peening of a thin plate is simulated using the concept of eigenstrain. As a further demonstration of the capabilities of the proposed approach, flexible plate theory is applied to the analysis of stresses and deformations arising due to local peening within a circular area. The results are of considerable use and significance for the analysis of shot peening and peen forming operations.
Spot-welded joints subjected to shear-tension loading. Part 1: Notch stress and strain range predictions and estimates for repeated loading
Authors: Gowhari-Anaraki A. R , Hardy S J , Fardad B 
Published: October 2005

A three-dimensional finite element model has been used to study the cyclic elastic-plastic stress and strain characteristics of a spot-welded joint subjected to repeated shear-tension loading. Four geometries, having low, medium, and high notch elastic stress concentration factors, are considered in this investigation. Two simple material behaviour models, e.g. elastic-perfectly plastic and kinematic hardening, are assumed. All results have been normalized with respect to material properties so that they can be applied to all geometrically similar spot-welded joints from other materials, which may be represented by the same material models. Normalized maximum steady state strain ranges are plotted as a function of the nominal load for the range of material hardening assumptions and notch elastic stress concentration factors. These plots can be used in the low cycle fatigue life design of such geometrically similar spot-welded specimens. The paper also compares finite element steady state strain range predictions with values estimated using simple notch stress-strain conversion rules for the four geometries and a range of nominal stresses. From this study, a ‘notch plastic flow sensitivity factor’, qp, to be used in conjunction with an intermediate rule, is suggested for estimating the strain range. Finally, a strain range estimate methodology, based on the notch elastic stress concentration factor, coupled with a multiaxial fatigue criterion and an intermediate rule, is then developed for this type of specimen and loading.
Spot-welded joints subjected to shear-tension loading. Part 2: Mixed-mode fracture parameters
Authors: Gowhari-Anaraki A. R , Hardy S J , Alipour R 
Published: October 2005

Fracture parameters that can be used in the fatigue analysis of spot-welded joints subjected to shear-tension loading, with local restraints, are presented. Finite element analysis has been used to obtain stress intensities in the vicinity of three different types of fatigue crack which, from practical experience, are introduced into a spot-welded joint, i.e. assumed notch crack, through-thickness crack, and through-nugget crack. A combination of elastic-plastic finite element and linear elastic fracture mechanics finite element analysis has been used and the results are presented in the form of fatigue and fracture parameters (i.e. structure configuration factor, notch configuration factor, crack configuration factor, and J-integral value) for a wide range of specimen and crack geometric parameters. These parameters are chosen to be representative of typical practical situations and have been determined from evidence presented in the open literature. The extensive range of structure, notch, and crack configuration factors obtained from the finite element analyses are then used to obtain equivalent prediction equations using a statistical multiple non-linear regression model. The accuracy of this model is measured using a multiple coefficient of determination, R2, where 0 ≤ R2 ≤ 1. This coefficient is found to be greater than or equal to 0.98 for all cases considered in this study, demonstrating the quality of the model fit to the data. Predictive equations for stress intensity factors and J-integral values, which are based on the elastic stress concentration factor, are also developed. Some approximate equations for crack configuration factors have been published in the past, all based on analytical solutions. All equations were derived in terms of two sets of non-dimensional parameters (i.e. the bending stress-membrane stress ratio at the nugget and the geometric ratio). These equations have to be coupled with a shell-beam finite element analysis in order to predict bending and membrane stresses at the weld nugget. Therefore, the accuracy of the results depends on the accuracy of the shell-beam finite element models used. In the present study, all prediction equations are directly related to the geometric ratios, which provides a simple and independent calculation procedure. Discrepancies between the results from the present study and those from the literature are discussed.
Application of Proteomic Technology in Identifying Pancreatic Secretory Trypsin Inhibitor Variants in Urine of Patients with Pancreatitis
Authors: Valmu Leena , Paju Annukka , Lempinen Marko , Kemppainen Esko , Stenman Ulf-Håkan 
Published: October 2005

AbstractBackground: Although the analysis of genetic variability has traditionally been performed with molecular genetic techniques, the development of proteomic technology has raised the possibility of analyzing genetic variants at the protein level. This method provides additional information about posttranslational modifications and differences in expression. We used mass spectrometry to characterize 3 variants of the peptide encoded by the serine protease inhibitor Kazal type 1 (SPINK1) gene, pancreatic secretory trypsin inhibitor (PSTI). A genetic variant of PSTI, N34S, is associated with the development of pancreatitis.Methods: We used a quadrupole/time-of-flight hybrid mass spectrometer equipped with an electrospray ionization source to analyze the molecular identity of PSTI purified from the urine of 12 patients with pancreatitis and from 3 controls. We also developed a rapid small-scale capture procedure to isolate and analyze PSTI from small volumes of urine.Results: The mutations responsible for mass shifts of different PSTI variants could be verified. We observed differences in the expression of different variants as well as a novel proteolytic fragment of PSTI. Small-scale magnetic bead–mediated immunoaffinity chromatography PSTI enabled easy and rapid purification from small urine volumes, facilitating mass spectrometric analysis with adequate sensitivity.Conclusions: Pancreatitis-related PSTI variants occurring at nanomolar concentrations in urine can be detected and quantified by immunoaffinity purification and mass spectrometry. In addition, the N34S variant occurs at higher concentrations than the wild type. This finding casts new light on the possible role of PSTI as a cause of hereditary pancreatitis.
Dipeptidyl-Peptidase IV Converts Intact B-Type Natriuretic Peptide into Its des-SerPro Form
Authors: Brandt Inger , Lambeir Anne-Marie , Ketelslegers Jean-Marie , Vanderheyden Marc , Scharpé Simon , De Meester Ingrid 
Published: October 2005

Abstract
Background: Analysis of plasma B-type natriuretic peptide (BNP) has suggested the in vivo formation of a truncated form, BNP (3–32), also called des-SerPro-BNP. The objectives of this study were to investigate (a) whether BNP and other natriuretic peptides are truncated by dipeptidyl-peptidase IV (DPP IV/CD26; EC 3.4.14.5) and (b) whether this truncation affects the susceptibility to cleavage by neutral endopeptidase (NEP; EC 3.4.24.11).
Methods: Human BNP (1–32), A-type natriuretic peptide 1–28 (ANP 1–28), and related peptides were incubated with purified DPP IV and with human plasma. In addition, BNP (1–32), BNP (3–32), and ANP (1–28) were subjected to hydrolysis by NEP. Cleavage products were analyzed by mass spectrometry.
Results: BNP (1–32) was cleaved by purified DPP IV with a specificity constant of 0.37 × 106 L · mol−1 · s−1. The DPP IV activity in EDTA-plasma was able to truncate BNP (1–32) ex vivo. Addition of Vildagliptin, a specific DPP IV inhibitor, prevented this truncation in a concentration-dependent manner. Under in vitro circumstances in which ANP was hydrolyzed extensively, BNP (1–32) and BNP (3–32) were very resistant to NEP-mediated cleavage.
Conclusions: DPP IV cleaves BNP (1–32) with an efficiency higher than or comparable to several known in vivo substrates of the enzyme. Even after loss of the amino-terminal dipeptide, BNP remains highly resistant to cleavage by NEP.
Neural Stem Cells Express Non-Neural Markers During Embryoid Body Coculture
Authors: Denham Mark , Huynh Trieu , Dottori Mirella , Allen Greg , Trounson Alan , Mollard Richard 
Published: October 2005

Abstract
The capacity of neural stem cells (NSC) to transdifferentiate into a wide range of non-neuronal lineages is the subject of debate. One approach to test NSC plasticity is to ectopically place NSCs in permissive or instructive microenvironments in which the signals driving differentiation of multiple cell types are being elicited. Here we produce embryoid body neurosphere aggregates by combining neurosphere derivatives from fetal mice constitutively expressing green fluorescent protein with embryonic stem (ES) cells isolated from Zin40 mice constitutively expressing nuclear β-galacosidase. Under these conditions, we assess neurosphere-derivative–immunoreactivity to anti-neurofilament heavy chain, anti-pan-cytokeratin, anti-smooth muscle α-actinin and anti-α-fetoprotein–specific antibodies. Furthermore, we determine lineage-specific transgene expression and undertake fluorescence in situ hybridization to assess ES cell–neural stem cell–fusion indices. Our data demonstrate that following coculture in hanging drops with ES cells, neurosphere derivatives display immunoreactivity to non-neural markers, in particular smooth muscle, which is not dependent upon cell–cell fusion. These results suggest that given an appropriate environment, NSC may lose their in vivo restrictions and display non-neuronal phenotypes.
Human Bone Marrow Stromal Cells Express a Distinct Set of Biologically Functional Chemokine Receptors
Authors: Honczarenko Marek , Le Yi , Swierkowski Marcin , Ghiran Ionita , Glodek Aleksandra M. , Silberstein Leslie E. 
Published: October 2005

AbstractStromal cells isolated from bone marrow (BMSCs), often referred to as mesenchymal stem cells, are currently under investigation for a variety of therapeutic applications. However, limited data are available regarding receptors that can influence their homing to and positioning within the bone marrow. In the present study, we found that second passage BMSCs express a unique set of chemokine receptors: three CC chemokine receptors (CCR1, CCR7, and CCR9) and three CXC chemokine receptors (CXCR4, CXCR5, and CXCR6). BMSCs cultured in serum-free medium secrete several chemokine ligands (CCL2, CCL4, CCL5, CCL20, CXCL12, CXCL8, and CX3CL1). The surface-expressed chemokine receptors were functional by several criteria. Stimulation of BMSCs with chemokine ligands triggers phosphorylation of the mitogen-activated protein kinase (e.g., extracellular signal–related kinase [ERK]-1 and ERK-2) and focal adhesion kinase signaling pathways. In addition, CXCL12 selectively activates signal transducer and activator of transcription (STAT)-5 whereas CCL5 activates STAT-1. In cell biologic assays, all of the chemokines tested stimulate chemotaxis of BMSCs, and CXCL12 induces cytoskeleton F-actin polymerization. Studies of culture-expanded BMSCs, for example, 12–16 passages, indicate loss of surface expression of all chemokine receptors and lack of chemotactic response to chemokines. The loss in chemokine receptor expression is accompanied by a decrease in expression of adhesion molecules (ICAM-1, ICAM-2, and vascular cell adhesion molecule 1) and CD157, while expression of CD90 and CD105 is maintained. The change in BMSC phenotype is associated with slowing of cell growth and increased spontaneous apoptosis. These findings suggest that several chemokine axes may operate in BMSC biology and may be important parameters in the validation of cultured BMSCs intended for cell therapy.
Cultivation of Human Embryonic Stem Cells Without the Embryoid Body Step Enhances Osteogenesis In Vitro
Authors: Karp Jeffrey M. , Ferreira Lino S. , Khademhosseini Ali , Kwon Albert H. , Yeh Judy , Langer Robert S. 
Published: October 2005

Abstract
Osteogenic cultures of embryonic stem cells (ESCs) are predominately derived from three-dimensional cell spheroids called embryoid bodies (EBs). An alternative method that has been attempted and merits further attention avoids EBs through the immediate separation of ESC colonies into single cells. However, this method has not been well characterized and the effect of omitting the EB step is unknown. Herein, we report that culturing human embryonic stem cells (hESCs) without the EB stage leads to a sevenfold greater number of osteogenic cells and to spontaneous bone nodule formation after 10–12 days. In contrast, when hESCs were differentiated as EBs for 5 days followed by plating of single cells, bone nodules formed after 4 weeks only in the presence of dexamethasone. Furthermore, regardless of the inclusion of EBs, bone matrix formed, including cement line matrix and mineralized collagen, which displayed apatitic mineral (PO4) with calcium-to-phosphorous ratios similar to those of hydroxyapatite and human bone. Together these results demonstrate that culturing hESCs without an EB step can be used to derive large quantities of functional osteogenic cells for bone tissue engineering.
Cover Picture: Fabrication and Electrical and Mechanical Properties of Carbon Nanotube Interconnections (Adv. Funct. Mater. 11/2005)
Authors: Wang M. S. , Wang J. Y. , Chen Q. , Peng L.‐M. 
Published: October 2005

AbstractThe fabrication of carbon nanotube (CNT) structures, including simple tube–tube connections, crossed junctions, T‐junctions, zigzag structures, and even nanotube networks, has been achieved by cutting and soldering CNTs using electron‐beam‐induced deposition of amorphous carbon (a‐C), as detailed in the work of Peng and co‐workers on p. 1825. These CNT structures have been constructed with a high degree of control, and it is found that the electric conductance and mechanical strength of the junctions can be improved by the deposition of a‐C and by increasing the contact area of the junctions.Individual carbon nanotubes (CNTs) have been cut, manipulated, and soldered via electron‐beam‐induced deposition of amorphous carbon (a‐C) and using a scanning tunneling microscope inside a transmission electron microscope. All CNT structures, including simple tube–tube connections, crossed junctions, T‐junctions, zigzag structures, and even nanotube networks, have been successfully constructed with a high degree of control, and their electrical and mechanical properties have been measured in situ inside the transmission electron microscope. It is found that multiple CNTs may be readily soldered together with moderate junction resistance and excellent mechanical resilience and strength, and the junction resistance may be further reduced by current‐induced graphitization of the deposited a‐C on the junction.
Surveillance of hearing loss among older construction and trade workers at Department of Energy nuclear sites
Authors: Dement John , Ringen Knut , Welch Laura , Bingham Eula , Quinn Patricia 
Published: October 2005

AbstractBackgroundMedical screening programs at three Departments of Energy (DOE) nuclear weapons facilities (Hanford Nuclear Reservation, Oak Ridge, and the Savannah River Site) have included audiometric testing since approximately 1996. This report summarizes hearing evaluations through March 31, 2003.MethodsOccupational examinations included a medical history, limited physical examination, and tests for medical effects from specific hazards, including audiometric testing. Hearing thresholds by frequency for DOE workers were compared to age‐standardized thresholds among an external comparison population of industrial workers with noise exposures <80 dBA. Multivariate analyses were used to explore the risk of hearing impairment by duration of construction trade work and self‐reported noise exposure, while controlling for potential confounders such as age, race, sex, smoking, elevated serum cholesterol, hypertension, solvent exposures, and recreational noise exposures.ResultsHearing thresholds among DOE workers were much higher than observed in a comparison population of industrial workers with low noise exposures. Overall, 59.7% of workers examined were found to have material hearing impairment by NIOSH criteria. Age, duration of construction work, smoking, and self‐reported noise exposure increased the risk of hearing loss. The risk of material hearing impairment was significantly elevated for construction trade workers compared to the external comparison population (odds‐ratio = 1.6, 95% CI = 1.3–2.1) and increased with the duration of trade work.ConclusionsThese medical screening programs confirm worker concerns about risks for hearing loss and the need for hearing conservation programs for construction workers, with emphasis on the prevention of noise exposures. Am. J. Ind. Med. 48:348–358, 2005. © 2005 Wiley‐Liss, Inc.
Pulmonary abnormalities associated with occupational exposures at the Savannah River site
Authors: Makie Toshio , Adcock David , Lackland Daniel T. , Hoel David G. 
Published: October 2005

AbstractBackgroundA program of medical evaluation for former Savannah River Site (SRS) workers at health effects due to exposures to hazardous or radioactive agents was conducted.MethodsThis study includes data from 1,368 participants aged 45 years or older who were assessed regarding work‐history and exposures to industrial agents. According to the standard industrial classification (SIC), participants were employed in five of the SIC divisions. Based on the International Labour Office Classification of Radiographs, two categories of pleural and parenchymal abnormalities were evaluated by a single radiologist. The SRS results were compared with the second national health and nutrition examination survey (NHANES II) results.ResultsThe odds ratio of the SRS male aged 45–75 compared to NHANES was 2.4 for pleura abnormalities and 0.8 for parenchymal abnormalities. Using logistic regression, the highest‐risk worker division was construction (OR = 2.76); asbestos exposure was clearly associated with pleural abnormality (OR = 2.15).ConclusionsPulmonary abnormalities were higher in former SRS workers than that in general population. Asbestos and possibly other exposures were related to pulmonary disease in this population. Am. J. Ind. Med. 48:365–372, 2005. © 2005 Wiley‐Liss, Inc.
The effect of ergonomic interventions in healthcare facilities on musculoskeletal disorders
Authors: Fujishiro Kaori , Weaver Jean L. , Heaney Catherine A. , Hamrick Christopher A. , Marras William S. 
Published: October 2005

AbstractBackgroundThe high incidence of musculoskeletal disorders (MSDs) among healthcare workers suggests that the introduction of ergonomic interventions could be beneficial. While laboratory studies have clearly documented the efficacy of ergonomic devices, few studies have examined their effectiveness in the healthcare workplace.MethodsThis study evaluated a statewide program that provided ergonomic consultation and financial support for purchasing ergonomic devices, which aid in patient handling and lifting. Changes in MSD rates between baseline (1 year pre‐intervention) and post‐intervention (up to 2 years) periods were examined in 100 work units in 86 healthcare facilities.ResultsThe median MSD rate decreased from 12.32 to 6.64 per 200,000 employee‐hours, a decrease greater than the secular trend for the study period (1999–2003).ConclusionsThis study suggests that ergonomic consultation and financial support for purchasing ergonomic equipment can be an effective intervention to reduce MSDs among healthcare workers. Am. J. Ind. Med. 48:338–347, 2005. © 2005 Wiley‐Liss, Inc.
13C NMR investigation of the reaction in water of UF resins with blocked emulsifiable isocyanates
Authors: Despres A. , Pizzi A. , Delmotte L. 
Published: October 2005

AbstractA solid state 13C NMR study of hardened networks obtained by the reaction of blocked and nonblocked isocyanates (pMDI) with urea‐formaldehyde (UF) resins in water showed different results according to the temperature of the reaction. At high temperature, in water, both a nonblocked or an emulsifiable, blocked isocyanate, appear to crosslink with UF resins through the formation both of traditional methylene bridges connecting urea to urea and of urethane bridges. The latter have been confirmed by 13C NMR to form in water by reaction of the isocyanate NCO group with the hydroxymethyl groups of the UF resin. At ambient temperature, UF/pMDI resins where the pMDI is a emulsifiable blocked isocyanate, do not appear to form urethanes to any great extent but rather to crosslink through the usual UF resin urea to urea methylene bridges. Even in this case, when urethane bridges appear to be absent, evidence of crosslinking in water through reaction of the isocyanate with the NH2 and NH amide of the UF resin has not been observed. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 589–596, 2006