bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of Diagnostic Accuracies in Outpatients and Hospitalized Patients of D-Dimer Testing for the Evaluation of Suspected Pulmonary Embolism
Authors: Schrecengost John E , LeGallo Robin D , Boyd James C , Moons Karel G M , Gonias Steven L , Rose C Edward , Bruns David E 
Published: February 2004

Abstract
Background: The ability of various D-dimer assays to exclude the diagnosis of thromboembolic diseases is controversial. We examined the diagnostic accuracy of two D-dimer methods in hospitalized patients and outpatients.
Methods: We studied consecutive patients for whom D-dimer testing was ordered for investigation of suspected pulmonary embolism. We measured D-dimer by an ELISA (VIDAS D-dimer) and an enhanced microlatex immunoassay method (Diagnostica Stago STA Liatest D-di). Patient diagnoses were based on imaging studies or, when these were not performed, on follow-up by review of medical records 3 months later.
Results: We examined 233 hospitalized patients and 234 outpatients with a mean age of 58 years (range, 1–92 years) and a female-to-male ratio of 1.4 to 1. Thromboembolism was present in 8% of outpatients and 12% of hospitalized patients. In outpatients, the negative predictive values were 98% [95% confidence interval (CI), 93–100%] and 99% (94–100%) for the microlatex and ELISA methods, respectively, at the recommended cutoffs. Areas under the ROC curves were similar for the two methods [0.77 (95% CI, 0.67–0.87) and 0.81 (0.73–0.89), respectively]. By contrast, in hospitalized patients, the confidence intervals for the areas under the ROC curves included 0.5 [0.60 (95% CI, 0.50–0.71) and 0.56 (0.44–0.67)].
Conclusions: For hospitalized patients, in contrast to outpatients, the diagnostic accuracy of D-dimer testing for pulmonary embolism is poor in a tertiary care setting, presumably reflecting thrombosis and comorbidities, other than pulmonary embolism, that increase the D-dimer concentrations in these patients. The patient population studied appears more important than assay method in studies of the diagnostic accuracy of D-dimer testing.
Regulation of Serum Paraoxonase Activity by Genetic, Nutritional, and Lifestyle Factors in the General Population
Authors: Ferré Natàlia , Camps Jordi , Fernández-Ballart Joan , Arija Victoria , Murphy Michelle M , Ceruelo Santiago , Biarnés Elisabet , Vilella Elisabet , Tous Mónica , Joven Jorge 
Published: February 2004

AbstractBackground: Paraoxonase may protect lipoproteins and cell membranes from peroxidation, and alterations in the activity of this enzyme have been associated with some chronic diseases. Serum paraoxonase appears to be mainly under genetic control, but some studies suggest that environmental factors may also modulate its activity. The aim of the present study was to investigate whether diet and lifestyle affect serum paraoxonase activity.Methods: We studied a population-based sample of 388 individuals (194 women and 194 men; age range, 18–75 years) and assessed their daily dietary intake using a 3-day estimated food record. The variables studied included serum paraoxonase activity, paraoxonase polymorphisms at positions 55 and 192, age, gender, smoking status, physical exercise, body mass index, energy consumption, nutrient intake (total lipids, saturated fatty acids, β-carotenes, vitamins C and E), and serum lipid concentrations.Results: Multiple linear regression analysis showed that only genetic polymorphisms, serum cholesterol, HDL-cholesterol concentrations, and cigarette smoking were significant predictors of serum paraoxonase activity. HDL-cholesterol concentrations were also related to body mass index, daily energy consumption, and saturated fatty acid intake.Conclusions: The between-individual variability of serum paraoxonase activity is regulated mainly by genetic determinants. Although HDL-cholesterol and tobacco smoking may contribute to the modulation of this enzyme, the other nutritional and lifestyle factors do not seem to play a significant role.
Potential Usefulness of Inflammatory Markers to Monitor Respiratory Functional Impairment in Sarcoidosis
Authors: Rothkrantz-Kos Snježana , van Dieijen-Visser Marja P , Mulder Paul G H , Drent Marjolein 
Published: February 2004

AbstractBackground: Sarcoidosis is a multiorgan inflammatory granulomatous disorder of unknown origin for which adequate markers to monitor disease severity are lacking. The aim of this study was to evaluate the potential clinical usefulness of serologic markers of inflammation [high-sensitivity C-reactive protein (hs-CRP) and serum amyloid A (SAA)], T-cell activation [soluble interleukin-2 receptor (sIL2R)], and granuloma formation [angiotensin-converting enzyme (ACE)] for monitoring of sarcoidosis.Methods: Of the 185 sarcoidosis patients who visited the Sarcoidosis Management Center between 1999 and 2002, we selected 144 nonsmoking patients: 73 untreated (group I) and 71 treated (group II). Subgroups of the untreated patients [group Ia (nonchronic group with time since diagnosis ≤2 years) and group Ib (chronic group with time since diagnosis &gt;2 years)] were evaluated separately. ROC curves and logistic regression analyses were used to compare the diagnostic accuracy of different markers to assess disease severity. Pulmonary disease severity was defined by lung function test results.Results: In untreated subgroup Ia and the total untreated group (group I), sIL2R had the largest areas under the curves (AUCs; 0.891 and 0.799, respectively) and the highest sensitivity (82% and 64%), specificity (94% and 88%), and positive (82% and 70%) and negative (94% and 88%) predictive values among the evaluated markers in both untreated groups. Nevertheless, the confidence intervals for sIL2R AUC, sensitivity, and specificity were broad and partly overlapped those of ACE, hs-CRP, and SAA. In the treated group (group II), all four markers appeared to have comparable AUCs, ranging from 0.645 for SAA to 0.711 for sIL2R.Conclusion: sIL2R appears to be useful for monitoring respiratory disease severity in sarcoidosis. We recommend sIL2R measurement in the follow-up of patients with sarcoidosis.
Grundausbildung in der Automatisierungstechnik (Basic Courses in Automatic Control)
Authors: Litz Lothar , Lunze Jan 
Published: February 2004

Abstract
Dieser Beitrag greift die Frage nach dem Inhalt von Einführungsvorlesungen in das Gebiet der Automatisierungstechnik auf und plädiert für eine Verbreiterung des behandelten Stoffes. An zwei in den letzten Jahren neu eingeführten Lehrveranstaltungen wird gezeigt, wie man diese Forderung mit modernen Lehrkonzepten erfüllen kann.
Rapid Control Prototyping in der Lehre (Rapid Control Prototyping in Education)
Authors: Schloßer Axel , Bollig Alexander , Abel Dirk 
Published: February 2004

Abstract
Die Regelungs-, Steuerungs- und Automatisierungstechnik ist als fachübergreifende und methodenorientierte Disziplin im Bereich der Ingenieursausbildung fest etabliert. Gerade diese positiven Eigenschaften bedingen jedoch auch eine starke mathematische Ausrichtung der Grundlagenausbildung, der häufig weitere eher theoretische Vertiefungsvorlesungen folgen. Dies führt dazu, dass in vielen Fällen die Vermittlung von Fähigkeiten zur Übertragung der Methoden auf reale Prozesse – speziell das "Engineering" – unterrepräsentiert ist. In diesem Bereich stehen heute jedoch immer leistungsfähigere Rechnerwerkzeuge unterstützend zur Verfügung. Der Beitrag zeigt auf, welche neuen Anforderungen und Möglichkeiten sich aufgrund der zunehmend rechnergestützten Entwurfsprozesse für die Lehrinhalte der Regelungs-, Steuerungs- und Automatisierungstechnik ergeben und wie diese Anforderungen im universitären Umfeld vermittelt werden können.
Integration und Interaktion: Möglichkeiten des Einsatzes von Notebooks und Internet in der regelungstechnischen Lehre (Integration and Interaction: Opportunities of Using Notebooks and Internet for Teaching in Control Engineering)
Authors: Schumm Peter , Bullinger Eric , Schweickhardt Tobias , Allgöwer Frank 
Published: February 2004

Abstract
In Schulen werden bereits seit einigen Jahren Notebooks für den Einsatz in der Lehre erprobt und auch schon erfolgreich eingesetzt. Neu hingegen sind die aktuellen Bestrebungen, Laptops auch in die Hochschul-Ausbildung einzubinden. Der erste Teil dieses Beitrags gibt einen Überblick über das Konzept des BMBF-Projekts Notebook University. Im zweiten Teil wird der konkrete Einsatz von Notebooks für die regelungstechische Ausbildung anhand des Projekts eLearnIng. beschrieben.
Regelungstechnik multimedial, Lernen am PC (Multimedia for Control Theory, PC-based Learning)
Authors: Hoyer Helmut , Gerke Michael , Laaser Wolfram 
Published: February 2004

Abstract
Dieser Beitrag beschreibt einen multimedialen Lernkurs zur Regelungstechnik, so wie sie in Grundlagenvorlesungen an wissenschaftlichen Hochschulen gelehrt wird. Der Lernkurs wird ergänzt durch eine Simulationsumgebung, die zu Übungszwecken und für praktische Anwendungen einsetzbar ist. Dieser multimediale Kurs dient als Unterstützung bei der heimischen Nachbearbeitung von Lerninhalten durch Studierende sowie zur Wiederauffrischung von Wissensinhalten bei bereits berufstätigen Ingenieuren. Daher berücksichtigt er die speziellen Bedürfnisse sowohl der Fernlehre als auch des lebenslangen Lernens. Die auf einer CD-ROM basierende Version dieser Lernumgebung wird hier vorgestellt. Wir berichten von methodischen Aspekten und gewonnenen Erfahrungen während ihrer Erstellung und geben Resultate aus einer studentischen Evaluation wieder.
LEARN2CONTROL – Projektorientiertes Lernen für ein besseres Gesamtverständnis in der regelungstechnischen Ausbildung (LEARN2CONTROL – Project-oriented Learning for a Better Understanding in Control Engineering Education)
Authors: Liefeldt Andreas , Völker Marten , Remelhe Manuel , Dadhe Kai , Engell Sebastian , Fritsch Carsten , Markgraf Norman 
Published: February 2004

Abstract
LEARN2CONTROL ist eine computergestützte Lernumgebung, die es ermöglicht, vorhandenes Grundlagenwissen im Bereich der Regelungstechnik durch selbstständiges Lernen in einem projektorientierten Umfeld zu vertiefen. Der Lernschwerpunkt liegt dabei besonders auf der Vermittlung der inneren Abhängigkeiten und Wechselwirkungen der unterschiedlichen Verfahren und Methoden der Regelungstechnik.
Ultra-Microelectrode Voltammetric Measurement of the Hydrodynamic Radii and Shear Plane of Micellar Particles for Sodium Dodecyl Sulfate in Aqueous NaCl Solutions
Authors: Yang Zhenyu , Zhao Jinsheng , Xie Yu , Yin Xiuli , Du Zhankui , Yang Zhengyu 
Published: February 2004

Abstract
Ultra-microelectrode voltammetric measurements have been performed on sodium dodecyl sulfate (SDS) in the aqueous NaCl solutions at 298.2 ± 0.1 K. The hydrodynamic radii (R
h
0) of micellar particles are calculated. The results suggest that R
h
0 decrease initially due to collapse of the shear plane toward the micelle hard-sphere surface, and then R
h
0 increase gradually due to electrolyte-induced linear spherical expansion of the micellar particles. Based on it, the location of micellar shear plane, the relationship between the shear plane and Debye–Hückel length, and the associated ζ-potential are also estimated. It is found that the relationship between the shear plane and Debye–Hückel length is linear, and, in different NaCl concentrations, the shear plane is almost located at a constant shear potential of 77 ± 10 mV, close to the hard-sphere surface of SDS micelle particles.
Viscosity Coefficients of NaSCN, KSCN, NH4SCN and MnSO4, CoSO4, NiSO4, CdSO4 in Aqueous Binary Mixtures of N,N-Dimethylformamide at 20 °C
Authors: Tsierkezos Nikos G. , Molinou Ioanna E. 
Published: February 2004

Abstract
Viscosities of sodium, potassium, ammonium thiocyanates and manganese, cobalt, nickel, cadmium sulfates have been measured in water + N,N-dimethylformamide (DMF) mixtures at 20 °C. The experimental data have been analyzed using the Jones–Dole equation and the B coefficients have been calculated. The results have been discussed in terms of ion-solvent and solvent-solvent interactions.
Electrical Conductances and Viscosities of Tetrabutylammonium Thiocyanate in Acetonitrile in the Temperature Range 25–45 °C
Authors: Chakraborty Jayanti Moitra , Das Bijan 
Published: February 2004

Abstract
The electrical conductances and viscosities of the solutions of tetrabutylammonium thiocyanate (Bu4NCNS) in acetonitrile have been reported at 25, 30, 35, 40 and 45 °C. The conductance data have been analyzed by the 1978 Fuoss conductance-concentration equation in terms of the limiting molar conductance (Λ0), the association constant (K
Λ) and the association diameter (R). The viscosity data have been analyzed by the Jones–Dole equation for the associated electrolytes to evaluate the viscosity B-coefficients of the electrolyte. These data have also been analyzed by the transition-state treatment to obtain the contribution of the solutes to the free energy of activation for viscous flow of the solution. The ionic contributions to the limiting molar conductance (Λ0), the viscosity B-coefficient and the free energy of activation for viscous flow have been estimated using the “reference electrolyte” tetrabutylammonium tetraphenylborate (Bu4NBPh4). Slight ionic association was always found for this salt in this solvent medium. The tetrabutylammonium ion is found to be unsolvated whereas the thiocyanate ion undergoes solvation in acetonitrile in the temperature range investigated here.
New Method to Analyse IR-Studies of Monomer-Dimer Self-Association: 2,2-Dimethyl-3-Ethyl-3-Pentanol in Carbon Disulfide as an Example
Authors: Chen Jenn-Shing , Kao Dah-Yu 
Published: February 2004

Abstract
Two new equations have been derived to treat the IR data from the monomer-dimer self-association. Equation (9), in the text, is to regress the integrated absorbances of the monomer bands to determine the molar absorptivity of the monomer band, ε
m, and the dimerization constant, K. Equation (13), in the text, is to regress those of dimer band to obtain the molar absorptivity of the dimer band, ε
d, and dimerization constant K. The self-association in the dilute solution of 2,2-dimethyl-3-ethyl-3-pentanol in carbon disulfide at different temperatures has been used as an example to demonstrate the usage of these two equations. The discrepancy between the values of K at the same temperature determined either from the monomer band or from the dimer band can be used as a criterion for the goodness of determination. The standard enthalpy and entropy of dimerization have also been obtained via a van’t Hoff plot from the data of K at different temperatures. The advantages of this new approach have also been discussed.
Jäntti’s Method for the Fast Measurement of Adsorption Combined with Diffusion
Authors: Poulis Johannes A. , Massen Carel H. , Robens Erich , Reichenauer Gudrun 
Published: February 2004

Abstract
On the basis of a molecular model for adsorption kinetics Jäntti introduced a method to calculate equilibria immediately after a change of the pressure of the sorptive gas. In the present paper we show the usefulness of the Jäntti-approach to multilayer adsorption combined with diffusion of the adsorbate into the solid.
Ionic Liquids: Promising Solvents for Electrochemistry
Authors: Endres Frank 
Published: February 2004

Abstract
Ionic liquids are solvents that are solely composed of ions. By definition their melting points are below 100 °C. Typical cations are substituted imidazolium ions, like 1-butyl-3-methylimidazolium, or tetraalkylammonium ions, like e.g. trioctyl-methyl-ammonium. Some important anions are hexafluorophosphate, trifluoromethylsulfonate, bis(trifluoromethylsulfonyl)imide. Many ionic liquids have negligible vapour pressures even at temperatures of 300 °C and more, they can have viscosities similar to water, ionic conductivities of up to 0.1 (Ω cm)−1, and, which makes them interesting for electrochemistry, wide electrochemical windows of more than 6 Volt. In this review article recent results of the author are summarized. It is shown that with the scanning tunneling microscope the processes during phase formation can be probed in situ with high quality. An important result is that semiconductors, shown at the example of germanium, can be made electrochemically on the nanoscale and that the electronic properties (band gap) can be measured in situ with current/voltage tunneling spectroscopy. Ionic liquids will gain a rising interest in electrochemistry as elements and compounds can be made electrochemically which are not accessible by conventional aqueous or organic electrochemistry.
Effect of steroid hormones on tissue remodelling and progesterone receptors in the uterus of seasonally anoestrous brushtail possums (Trichosurus vulpecula)
Authors: Sizemore R J , Hurst P R , McLeod B J 
Published: February 2004

This study describes progesterone receptor (PR) location within uterine cells and associated morphological changes to the uterine luminal and glandular epithelium in seasonally anoestrous brushtail possums treated with oestradiol and/or progesterone.Twenty-four adult female possums (n= 6/group) were treated with oestradiol, progesterone, oestradiol followed by progesterone or with the oil vehicle alone for 6-day periods. Uterine tissue was recovered, weighed and processed for light and transmission electron microscopy and for immunohistochemistry for PRs. Stereological techniques were used to quantify epithelial cell and constituent volumes for both luminal and glandular tissues. Plasma concentrations of oestradiol and progesterone were determined by radioimmunoassay.Mean uterine wet weights were significantly heavier (P< 0.001) following oestradiol/progesterone treatment and maximum gland dilation, cellular and stromal growth, maximum cell height, and cell and constituent volumes were recorded after this treatment regimen. Cell nuclei and debris were commonly observed in gland lumina, and nuclear PRs were found predominantly in stromal cells following oestradiol-only treatment. Sequential treatment with oestradiol and then progesterone caused a decline in the number of positively stained cells. Epithelial cells contained extensive secretory organelles and degenerating cells were common within the glands.Oestradiol treatment induced cell and cell constituent growth and promoted PR formation in anoestrous possum uterine tissue. Subsequent exposure to progesterone stimulated uterine tissues to reach maximum wet weights and led to the cellular maturation necessary to remodel the uterus in preparation for pregnancy.
Creep Resistant Magnesium Alloys for Powertrain Applications
Authors: Pekguleryuz M.O. , Kaya A.A. 
Published: February 2004

AbstractCreep resistant magnesium alloys are candidate materials for automotive powertrain applications. Since the 90's, a number of new creep‐resistant magnesium alloy systems have been investigated and developed. These are for the most part based on rare‐earth, alkaline earth, and silicon additions. This paper gives an overview of creep resistance in magnesium and a review of creep resistant magnesium alloys for power‐train applications.
Understanding Magnesium Corrosion—A Framework for Improved Alloy Performance
Authors: Song G. , Atrens A. 
Published: February 2004

AbstractThe purpose of this paper is to provide a succinct but nevertheless complete mechanistic overview of the various types of magnesium corrosion. The understanding of the corrosion processes of magnesium alloys builds upon our understanding of the corrosion of pure magnesium. This provides an understanding of the types of corrosion exhibited by magnesium alloys, and also of the environmental factors of most importance. This deep understanding is required as a foundation if we are to produce magnesium alloys much more resistant to corrosion than the present alloys. Much has already been achieved, but there is vast scope for improvement. This present analysis can provide a foundation and a theoretical framework for further, much needed research. There is still vast scope both for better fundamental understanding of corrosion processes, engineering usage of magnesium, and also on the corrosion protection of magnesium alloys in service.
Die Casting for High Performance—Focus on Alloy Development
Authors: Bakke P. , Westengen H. 
Published: February 2004

AbstractDevelopment of magnesium die casting alloys is the art of combining a thorough understanding of thermodynamic aspects of alloy composition and phase formation with the solidification kinetics as experienced in the die casting process. The microstructures obtained will determine The Alloy Property profile, which must be in line with the targeted application requirements. Successful development of an industrial alloy means that also The Diecasting Performance profile as well as the Alloy Production and Recycling profile must be fulfilled. In the present paper, a summary of current alloy development efforts will be given. Results from alloy development work by Hydro Magnesium will be presented, focusing mainly on creep resistant alloys. Specifically, alloys within the Mg‐Al‐RE system are highlighted.
Properties of Graphite‐Strengthened Magnesium
Authors: Ferkel H. 
Published: February 2004

AbstractMg was dispersion‐strengthened with graphite by powder metallurgy. The material was produced by ball milling Mg micropowder (median particle diameter 40 μm) with 3 vol.‐% graphite powder (median particle diameter 1–2 μm). After 8 h ball milling the product was consolidated by hot extrusion. Structural analysis revealed that a submicrocrystalline structure developed during ball milling. Tensile tests showed that the material was brittle even up to 300 °C and, therefore, most mechanical tests were carried out under compression. Under those conditions the reinforced material showed yield stresses of 270 MPa at ambient temperature, 170 MPa at 150 °C, and 125 MPa at 300 °C. Mg processed under the same conditions, but without graphite addition, had significantly lower yield stresses. The dispersion‐strengthened Mg showed a marked increase in creep resistance: at 200 °C and a stress, σc, of 100 MPa, the secondary creep rate, ϵs, was in the lower 10–9 s–1 range and at 300 °C and σc of 80 MPa, ϵs values of up to 1 × 10–8 s–1 were measured. The results are discussed.
Comparative Dimerization of 1‐Butene with a Variety of Metal Catalysts, and the Investigation of a New Catalyst for CH Bond Activation
Authors: Small Brooke L. , Schmidt Roland 
Published: February 2004

AbstractCatalytic dimerization of 1‐butene by a variety of catalysts is carried out, and the products are analyzed by gas chromatography and mass spectrometry. Catalysts based on cobalt and iron can produce highly linear dimers, with the cobalt‐based dimers exceeding 97 % linearity. Catalysts based on vanadium and aluminum prefer to make branched dimers, which are most often methyl‐heptenes in the case of vanadium and almost exclusively 2‐ethyl‐1‐butene in the case of aluminum. The vanadium catalyst also produces substantial amounts of dienes and alkanes, suggesting a competing hydrogenation/dehydrogenation pathway that appears to involve vinyl CH bond activation. Nickel catalysts are generally less selective than those based on iron or cobalt for making linear dimers, but they can make dimers with 60 % linearity. The major by‐products for the nickel systems are trisubstituted internal olefins. An important side reaction that must be considered for dimerization reactions is 1‐butene isomerization to 2‐butene, which makes recycling the butene difficult for a linear dimerization process. Aluminum, iron, and vanadium systems promote very little isomerization, but nickel and cobalt systems tend to isomerize the undimerized substrate heavily.