bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sedation Assessment in Critically Ill Adults: 2001–2004 Update
Authors: Watson Brian D , Kane-Gill Sandra L 
Published: September 2004

OBJECTIVE To review recently published literature on the validity and reliability of sedation assessment tools in critically ill adults and evaluate the potential advantages and disadvantages of each. DATA SOURCES A computerized search of MEDLINE and PubMed (2001–May 2004) was conducted. STUDY SELECTION AND DATA EXTRACTION Sedation assessment tools used in adult intensive care units (ICUs) were identified. DATA SYNTHESIS Six subjective and 3 objective assessment tools were identified. Four subjective assessment tools have reliability and 4 have validity data published that were not previously available. There are reliability data to further support the use of the previously published Motor Activity Assessment Scale. Additional reliability data exist for the Ramsay Scale and Glasgow Coma Scale. Conflicting evidence is available with the use of the Bispectral Index monitor in the ICU. Recently, the Patient State Index and Auditory Evoked Potentials were introduced for objective monitoring in critically ill patients. CONCLUSIONS Increasing data on sedation assessment were published over the last few years, probably in response to supporting evidence that goal-driven sedation therapy improves patient outcomes. Reliability and/or validity testing exists for many of these scales. Several useful tools are available to guide sedation therapy in critically ill patients.
Population Pharmacokinetics II: Estimation Methods
Authors: Ette Ene I , Williams Paul J 
Published: September 2004

OBJECTIVE To present, compare, and contrast the various approaches to estimating population pharmacokinetic (PPK) models with respect to the mathematical foundation, statistical aspects, software programs for implementation, and underlying assumptions. DATA SOURCES Information on PPK was retrieved from a MEDLINE search (1977–August 2004) of literature and a bibliographic review of review articles and books. This information is used in conjunction with experience to explain the various methodologic approaches to PPK. STUDY SELECTION AND DATA EXTRACTION All articles indentified from data sources were evaluated and relevant information was included in this review. DATA SYNTHESIS Over 80 articles dealing with PPK estimation methods and/or their implementation were identified and reviewed. Sixty-four of these were chosen for their direct relevance to the subject of this article. Different estimation methods ranging from the naïve averaging and naïve pooled approaches through the standard two-stage approach to the nonlinear mixed-effects modeling approaches for estimating PPK are reviewed with their advantages and limitations. CONCLUSIONS PPK estimation methods that rely on the characterizing of mixed (fixed and random) effects are known to produce PPK parameter estimates that are less biased than those obtained using the naïve and standard two-stage approaches. The NONMEM software is the most widely used software for the characterization of PPK.
Mutation Analysis in Spanish Patients with Hereditary Hemorrhagic Telangiectasia: Deficient Endoglin Up-regulation in Activated Monocytes
Authors: Sanz-Rodriguez Francisco , Fernandez-L. Africa , Zarrabeitia Roberto , Perez-Molino Alfonso , Ramírez Jose R , Coto Eliecer , Bernabeu Carmelo , Botella Luisa M 
Published: September 2004

AbstractBackground: Mutations in the endoglin (ENG) or ALK1 genes are responsible for hereditary hemorrhagic telangiectasia types 1 and 2 (HHT1 and HHT2), respectively, a dominant vascular dysplasia caused by haploinsufficiency. No formal mutation studies of patients with HHT have been conducted in Spain.Methods: ENG and ALK1 mutation analyses were carried out in 13 Spanish HHT patients diagnosed according to the Curaçao criteria. Because endoglin is up-regulated at the cell surface during the monocyte-macrophage transition, endoglin concentrations in activated monocytes were determined by immunofluorescence flow cytometry in a systematic analysis. As controls, 40 non-HHT volunteers were studied for up-regulation of endoglin in activated monocytes.Results: The mutation responsible for HHT was identified in eight patients belonging to two unrelated families. One of the families has a nonsense mutation in exon 4 (c.511C&gt;T; R171X) of the ENG gene, and accordingly the disorder was identified as HHT1. The other family has a missense mutation affecting exon 8 (c.1120C&gt;T; R374W) of the ALK1 gene, and hence is a HHT2 family. Interestingly, endoglin up-regulation was deficient in activated monocytes of both HHT1 and HHT2 patients compared with controls. By contrast, endoglin up-regulation was age-independent in control donors across a broad range of ages. The extent of endoglin up-regulation in activated monocytes was most diminished in those patients with the most severe symptoms.Conclusions: Endoglin up-regulation in activated monocytes is impaired in HHT1 and HHT2 patients and is age-dependent in both HHT types. Endoglin expression may predict the clinical severity of HHT.
Evaluation of a Candidate Reference Measurement Procedure for Serum Free Testosterone Based on Ultrafiltration and Isotope Dilution–Gas Chromatography–Mass Spectrometry
Authors: Van Uytfanghe Katleen , Stöckl Dietmar , Kaufman Jean M , Fiers Tom , Ross H Alec , De Leenheer André P , Thienpont Linda M 
Published: September 2004

AbstractBackground: To assess the analytical validity of free testosterone (FTe) measurements, a reference measurement procedure (RMP) is required. For steroids, isotope dilution–mass spectrometry is accepted as state-of-the-art technology. Because FTe is defined as the hormone fraction in serum water in equilibrium with the protein-bound fraction, the RMP should include a physical separation step. The use of equilibrium dialysis (ED) or ultrafiltration (UF) is advocated. Our objective was to develop such a candidate RMP.Methods: We selected UF combined with isotope dilution–gas chromatography–mass spectrometry (ID-GC/MS) for direct measurement of Te in the ultrafiltrate. After optimization of the UF process, the complete procedure was validated by use of split-sample comparisons with indirect ED (iED) and symmetric dialysis (SyD).Results: The candidate RMP gave maximum within-day, between-day, and total CVs of 3.0%, 3.1%, and 4.3%. The Deming regression equations for the respective method comparisons were: UF-ID-GC/MS = 0.98(iED) − 53 pmol/L (r = 0.94; Sy|x= 42 pmol/L) and UF-ID-GC/MS = 0.92(SyD) + 21 pmol/L (r = 0.97; Sy|x= 31 pmol/L).Conclusions: We achieved the objective of a state-of-the-art candidate RMP, which agreed well with iED and SyD. However, we also demonstrated that a degree of discordance remains, which may require a decision from an authoritative organization on the recommended procedure to measure free hormone concentrations.
Mammaglobin as a Novel Breast Cancer Biomarker: Multigene Reverse Transcription-PCR Assay and Sandwich ELISA
Authors: Zehentner Barbara K , Persing David H , Deme Amadou , Toure Papa , Hawes Stephen E , Brooks Lisa , Feng Qinghua , Hayes Dawn C , Critichlow Cathy W , Houghton Raymond L , Kiviat Nancy B 
Published: September 2004

AbstractBackground: The aim of this study was to examine the potential usefulness of a mammaglobin multigene reverse transcription-PCR (RT-PCR) assay and a mammaglobin sandwich ELISA as diagnostic tools in breast cancer.Methods: We studied peripheral blood samples from 147 untreated Senegalese women with biopsy-confirmed breast cancer and gathered patient information regarding demographic, and clinical staging of disease. The samples were tested for mammaglobin and three breast cancer-associated gene transcripts by a multigene real-time RT-PCR assay and for serum mammaglobin protein by a sandwich ELISA assay.Results: In 77% of the breast cancer blood samples, a positive signal was obtained in the multigene RT-PCR assay detecting mammaglobin and three complementary transcribed genes. Fifty samples from healthy female donors tested negative. Significant correlations were found between mammaglobin protein in serum, presence of mammaglobin mRNA-expressing cells in blood, stage of disease, and tumor size. Circulating mammaglobin protein was detected in 68% of the breast cancer sera, and was increased in 38% in comparison with a mixed control population. The RT-PCR assay and the ELISA for mammaglobin produced a combined sensitivity of 84% and specificity of 97%.Conclusion: The ELISA and RT-PCR for mammaglobin and mammaglobin-producing cells could be valuable tools for diagnosis and prognosis of breast cancer.
Analysis of Pyrimidine Synthesis “de Novo” Intermediates in Urine and Dried Urine Filter- Paper Strips with HPLC–Electrospray Tandem Mass Spectrometry
Authors: van Kuilenburg André B P , van Lenthe Henk , Löffler Monika , van Gennip Albert H 
Published: September 2004

Abstract
Background: The concentrations of the pyrimidine “de novo” metabolites and their degradation products in urine are useful indicators for the diagnosis of an inborn error of the pyrimidine de novo pathway or a urea-cycle defect. Until now, no procedure was available that allowed the analysis of all of these metabolites in a single analytical run. We describe a rapid, specific method to measure these metabolites by HPLC–tandem mass spectrometry.
Methods: Urine or urine-soaked filter-paper strips were used to measure N-carbamyl-aspartate, dihydroorotate, orotate, orotidine, uridine, and uracil. Reversed-phase HPLC was combined with electrospray ionization tandem mass spectrometry, and detection was performed by multiple-reaction monitoring. Stable-isotope-labeled reference compounds were used as internal standards.
Results: All pyrimidine de novo metabolites and their degradation products were measured within a single analytical run of 14 min with lower limits of detection of 0.4–3 μmol/L. The intra- and interassay variation for urine with added compounds was 1.2–5% for urines and 2–9% for filter-paper extracts of the urines. Recoveries of the added metabolites were 97–106% for urine samples and 97–115% for filter-paper extracts of the urines. Analysis of urine samples from patients with a urea-cycle defect or pyrimidine degradation defect showed an aberrant metabolic profile when compared with controls.
Conclusion: HPLC with electrospray ionization tandem mass spectrometry allows rapid testing for disorders affecting the pyrimidine de novo pathway. The use of filter-paper strips could facilitate collection, transport, and storage of urine samples.
Historical Development and Future Prospects of Structural Silicone Sealants in China
Authors: Wang Y-L , Wang H-M , Wu L-M 
Published: September 2004

AbstractIn China, the first four-sided structurally glazed curtain wall building, the Beijing Great Wall Hotel, was constructed in 1987. Since then, glass curtain wall buildings have become popular, and it is estimated that about 5 million m2 of coated glass are fabricated and installed by way of Structural Silicone Glazing (SSG) every year. Structural silicone sealants from Dow Corning and General Electric (GE) held the largest share of China's market until 1998. China developed and decreed its own national standard GB 16776-1997 for structural silicone sealants that is comparable with ASTM C 1184 but that has more stringent requirements in terms of tensile strength and adhesion to substrates. All structural silicone sealants, whether they are manufactured domestically or overseas, are required to be approved by the Chinese government based on the GB 16776 specification, and only certified products are permitted for use in Chinese glass curtain wall engineering. There are currently eight foreign structural silicone sealants and ten domestic products approved for installation of glass curtain walls in China. This paper covers China's market, national standard, and prospects of structural silicone sealants.
Properties of 20% Cold-Worked 316 Stainless Steel Irradiated at Low Dose Rate
Authors: Allen TR , Tsai H , Cole JI , Ohta J , Dohi K , Kusanagi H 
Published: September 2004

Abstract
To assess the effects of long-term, low-dose-rate neutron exposure, tensile, hardness, and fracture properties were measured, and microstructural characterization was performed on irradiated 20% cold-worked Type 316 stainless steel. Samples were prepared from reactor core components retrieved from the EBR-II reactor following final shutdown. Sample locations were chosen to cover a dose range of 1–56 dpa at temperatures from 371–390°C and dose rates from 0.8–3.3 × 10−7 dpa/s. Irradiation caused hardening, with the ultimate tensile strength (UTS) reaching about 800 MPa near 20 dpa and appearing to saturate at higher doses. The yield strength (YS) follows approximately the same trend as the ultimate tensile strength. The work-hardening capability of the material decreases with increasing dose. While the material retained respectable ductility at 20 dpa, the uniform and total elongation decreased to &lt;1 and &lt;3%, respectively, at 47 dpa. Fracture in the 30 dpa specimen is mainly ductile but with local regions of mixed-mode failure, consisting mainly of dimples and microvoids. The fracture surface of the higher-exposure 47 dpa specimen displays more brittle features. Changes in yield strength predicted from the microstructural components are roughly consistent with the measured changes in yield strength.
New Methodologies for Developing Radiation Embrittlement Models and Trend Curves of the Charpy Impact Test Data
Authors: Wang JA , Rao NSV 
Published: September 2004

AbstractA new methodology is developed for the prediction of RPV embrittlement that utilizes a combination of domain models and nonlinear estimators including neural networks and nearest neighbor regressions. The Power Reactor Embrittlement Database is used in this study. The results from newly developed nearest neighbor projective fuser indicate that the combined embrittlement predictor achieved about 67.3% and 52.4% reductions in the uncertainties for General Electric Boiling Water Reactor plate and weld data compared to Regulatory Guide 1.99, Revision 2, respectively. The implications of irradiation temperature effects to the development of radiation embrittlement models are then discussed. A new methodology that incorporates the chemical compositions into the Charpy trend curve is also developed. The purpose of this new fitting procedure is to generate a new multi-space topography that can properly reflect the inhomogeneity of the surveillance materials and utilize this multi-space trend surface to link and project the surveillance test results to that of reactor pressure vessel steels.
The Macro-Microscopic Numerical Simulation of the Mechanical Behavior of CFCC with Matrix Anisotropic Damage by Homogenization Method
Authors: Luo D , Takezono S , Tao K , Minamoto H 
Published: September 2004

Abstract
In this paper, a damage constitutive model based on a micro-mechanical approach is established and used to predict the macro-microscopic elastic-brittle mechanical behavior of continuous fiber reinforced ceramic matrix composites (CFCC). Anisotropic damage is applied to describe the matrix phase damage which reflects all types of damage such as nucleation and coalescence of voids and micro-cracks that the matrix material undergoes. The asymptotic expansion homogenization method is used to obtain the effective mechanical properties of composites and to derive the homogenized damage elastic concentration factor and the gross stiffness matrix of unidirectional and cross-ply laminate composite materials. Internal variables are introduced to describe the evolution of the damage state and the degradation of the material stiffness. Using the proposed theory, the unidirectional composite and the cross-ply laminate composites with /03/90/03/, /03/902/03/, and /03/903/03/ stacking sequences are analyzed, and the numerical results are consistent with those of the experiments.
Extension of a Microstructure-Based Fatigue Crack Growth Model for Predicting Fatigue Life Variability
Authors: Enright MP , Chan KS 
Published: September 2004

Abstract
Most of the existing crack growth models rely on empirical constants derived from curve fits of data at specific test conditions. Although statistical information can be obtained for many of these constants, multiple experimental tests typically must be performed to represent the wide range of the response. In this paper, an alternative approach is presented that links fatigue crack growth parameters to material and microstructural size parameters via a microstructure-based fatigue crack growth (FCG) model. In addition, variation of initial crack size due to microstructural variation is modeled in terms of a crack-size-based fatigue crack initiation model. Variations of microstructural parameters are described in terms of a probabilistic framework. The probabilistic, microstructure-based, FCG approach is illustrated for a Ni-based superalloy in which the influence of changes in the main descriptors of the individual microstructural parameters on initial crack size, crack growth rate, and fatigue life is shown. Stochastic model results are compared with existing experimental data to illustrate the feasibility of the approach for predicting da/dN variability due to microstructure variations.
Application of Probabilistic Fracture Mechanics in Structural Design of Magnet Component Parts Operating Under Cyclic Loads at Cryogenic Temperatures
Authors: Yatomi M , Nyilas A , Portone A , Sborchia C , Mitchell N , Nikbin K 
Published: September 2004

AbstractThis paper presents a methodology for the use of probabilistic fracture mechanics concepts to estimate the design fatigue life and reliability of structural materials used in superconducting coils and magnet intercoil components of the International Thermonuclear Experimental Reactor (ITER). The orbitally welded conductor jackets of superconducting coils are subjected to fluctuating tensile stresses. The paper uses fatigue crack growth (FCGR) data at 7K from type 316LN stainless steel, in parent and weld material conditions, to predict fatigue crack growth rates using Monte Carlo analysis. Two stages are considered in which scatter could be quantified in the analysis. Initially, the unknown in crack length is taken as a stochastic variable. Secondly, the model assumes that the scatter observed in the correlation of the FCGR data versus ΔK is directly due to factors such as testing methods, measurement, material, and geometric variability and can therefore be quantified statistically. Either a normal or lognormal distribution of the scatter is assumed depending on the parameter. The purpose of this approach is to illustrate some of the advantages over a deterministic approach that most design codes use. An example is presented that compares the design life of a conductor jacket section containing a single crack and multiple cracks. A comparison of a sensitivity analysis for multiple cracks, for failure times at probabilities of 1 % and 0.001 %, with times calculated from a deterministic analysis using appropriate safety factors, suggests that the deterministic analysis give less conservative failure times.
Developing a Performance-Based Joint Sealant Specification for Airport PCC Pavements
Authors: Lacasse MA , Masson JF 
Published: September 2004

AbstractDespite recent progress to develop a performance-based specification for bituminous sealants applied to asphalt concrete (AC) roadways and runways, a performance-based specification for cold-applied joint sealants for Portland cement concrete (PCC) aprons, taxiways, and parking areas has yet to be mapped and developed. Unique in-service conditions exist on these PCC pavements, where sealants are not only exposed to climatic effects and heavy traffic loads, but also to jet fuel and de-icing fluids. Installation and maintenance conditions are also unique in that it is often necessary to install or replace joint sealants at night or in a very short time so that aircraft traffic disruption is avoided. Hence, special consideration must be provided to ascertain that joint sealants are effective and durable. Recent studies on joint and crack sealants used on airport pavements that experience cold climates indicate that current specifications do not necessarily allow for the selection of durable sealants, and therefore sealant failure can be rapid. To address the issue of premature failure and to extend joint sealant service life, the elements of a performance-based specification for cold-applied joint sealants for PCC airport pavements is reviewed. The benefits of such a specification include the selection of joint sealants for specific local needs, reduced airport pavement maintenance costs, and extended airport PCC pavement service life.
Issues Related to the Mechanical Property Characterization of Sealants
Authors: White CC , Hunston DL 
Published: September 2004

Abstract
Quantification of the mechanical properties of cured sealant is complicated by the presence of the Mullins effect. This paper examines the Mullins effect using five different sealants encompassing the range of properties and formulations found in commercial sealants. Three main observations include: the Mullins effect was observed in all sealant formulations studied, the Mullins effect was observed in both tension and compression strains, and there was a recovery of the Mullins effect after sufficient periods of time between repeated loading cycles. Simple rules were formulated to describe the Mullins effect. Moreover, the tests show that understanding the Mullins effect is crucial in characterizing the mechanical properties of a sealant.
Identification of Crystalline Behavior on Macroscopic Response and Local Strain Field Analysis: Application to Alpha Zirconium Alloys
Authors: Gélébart L , Crépin J , Dexet M , Sauzay M , Roos A 
Published: September 2004

AbstractThe purpose of this paper is to present an identification method of the crystalline behavior of a material from a mechanical test performed on a polycrystalline sample. Because of the lack of knowledge about its crystalline behavior, this method is applied to a Zirconium alloy. This identification is based on a finite element modeling of the microstructure, and the results are compared to both the macroscopic and the microscopic experimental results. On the microscopic scale, the plastic strains are obtained using a micro-extensometry technique and the crystalline orientation using an EBSD technique. In order to validate the method, an identification is performed with only two free parameters: the evolutions of the macroscopic and microscopic errors appear to be regular and exhibit a well-defined minimum so that the parameters can be clearly identified.