bluuebunny/crossref_metadata_2025_split huggingface dataset:
Technology, security, and individual privacy: New tools, new threats, and new public perceptions
Authors: Strickland Lee S. , Hunt Laura E. 
Published: December 2004

AbstractHighly portable information collection and transmission technologies such as radio frequency identification (RFID) tags and smart cards are becoming ubiquitous in government and business—employed in functions including homeland security, information security, physical premises security, and even the control of goods in commerce. And, directly or indirectly, in many of these applications, it is individuals and their activities that are tracked. Yet, a significant unknown is (a) whether the public understands these technologies and the manner in which personally identifiable information may be collected, maintained, used, and disseminated; and (b) whether the public consents to these information practices. To answer these and related questions, we surveyed a select group of citizens on the uses of this technology for business as well as homeland security purposes. We found a significant lack of understanding, a significant level of distrust even in the context of homeland security applications, and a very significant consensus for governmental regulation. We conclude that a primary objective for any organization deploying these technologies is the promulgation of a comprehensive Technology Privacy Policy, and we provide detailed specifications for such an effort.
Developmental gene expression profiling of mammalian, fetal orofacial tissue
Authors: Mukhopadhyay Partha , Greene Robert M. , Zacharias Wolfgang , Weinrich Martin C. , Singh Saurabh , Young William W. , Pisano M. Michele 
Published: December 2004

AbstractBACKGROUNDThe embryonic orofacial region is an excellent developmental paradigm that has revealed the centrality of numerous genes encoding proteins with diverse and important biological functions in embryonic growth and morphogenesis. DNA microarray technology presents an efficient means of acquiring novel and valuable information regarding the expression, regulation, and function of a panoply of genes involved in mammalian orofacial development.METHODSTo identify differentially expressed genes during mammalian orofacial ontogenesis, the transcript profiles of GD‐12, GD‐13, and GD‐14 murine orofacial tissue were compared utilizing GeneChip arrays from Affymetrix. Changes in gene expression were verified by TaqMan quantitative real‐time PCR. Cluster analysis of the microarray data was done with the GeneCluster 2.0 Data Mining Tool and the GeneSpring software.RESULTSExpression of >50% of the ∼12,000 genes and expressed sequence tags examined in this study was detected in GD‐12, GD‐13, and GD‐14 murine orofacial tissues and the expression of several hundred genes was up‐ and downregulated in the developing orofacial tissue from GD‐12 to GD‐13, as well as from GD‐13 to GD‐14. Such differential gene expression represents changes in the expression of genes encoding growth factors and signaling molecules; transcription factors; and proteins involved in epithelial‐mesenchymal interactions, extracellular matrix synthesis, cell adhesion, proliferation, differentiation, and apoptosis. Following cluster analysis of the microarray data, eight distinct patterns of gene expression during murine orofacial ontogenesis were selected for graphic presentation of gene expression patterns.CONCLUSIONSThis gene expression profiling study identifies a number of potentially unique developmental participants and serves as a valuable aid in deciphering the complex molecular mechanisms crucial for mammalian orofacial development. Supplementary material for this article can be found at http://www.mrw.interscience.wiley.com/suppmat/1542‐0752/suppmat/2004/70/v70.mukhopadhyay.html Birth Defects Research (Part A), 2004. © 2004 Wiley‐Liss, Inc.
Genetic approaches to identify disease genes for birth defects with cleft lip/palate as a model
Authors: Lidral Andrew C. , Murray Jeffrey C. 
Published: December 2004

AbstractBACKGROUNDUnderstanding the etiology of birth defects is an important step toward developing improved treatment and preventive strategies. Most birth defects have an underlying genetic basis, ranging from single genes playing dominant or recessive roles in Mendelian disorders to a mixture of contributions from multiple genes and environmental triggers in complex traits. The purpose of this article is to provide an overview of genetic approaches to identifying disease genes for genetically complex birth defects.METHODSA review of the literature describing successes and limitations for identifying disease genes for complex traits was conducted.RESULTSCleft lip and cleft palate are common congenital anomalies with significant medical, psychological, social, and economic ramifications. The Online Mendelian Inheritance in Man catalog (OMIM; http://www3.ncbi.nlm.nih.gov/Omim) lists more than 400 single‐gene causes of clefts of the lip and/or palate. Genetic causes of clefting also include chromosomal rearrangements, genetic susceptibility to teratogenic exposures, and complex genetic contributions of multiple genes.CONCLUSIONSGenetic causes of birth defects can be identified using an increasingly powerful combination of careful sample collection, molecular analytic methods, and statistical evaluations. We will describe a range of approaches to search for genetic factors of birth defects and use our own work with cleft lip and palate as a model. Birth Defects Research (Part A), 2004. © 2004 Wiley‐Liss, Inc.
Eigenspannungen in zweischichtigen Betonplatten, insbesondere mit nachträglich aufgebrachter zweiter Schicht
Authors: Sieber Edgar 
Published: December 2004

AbstractEigenspannungen in zweischichtigen Betonplatten infolge unterschiedlicher Volumenänderungen der Schichten aus Temperatureinwirkungen oder Schwinden können Ursache für Schäden sein. Es wird ein Rechenverfahren zur Bestimmung derartiger Eigenspannungen abgeleitet und an einem Beispiel, bei dem die zweite Schicht nachträglich aufgebracht worden ist, erläutert.
Risikountersuchung am Beispiel historischer Brücken unter Schiffsanprall
Authors: Curbach Manfred , Proske Dirk 
Published: December 2004

AbstractZur Bewertung der Sicherheit vorhandener Bauwerke wird der Sicherheitsbegriff in den Risikobegriff überführt. Anschließend werden verschiedene Parameter zur Abbildung von Risiken vorgestellt. Diese Parameter werden bei der Beurteilung der Sicherheit von zwei historischen Brücken über schiffbare Flüsse unter der möglichen Einwirkung Schiffsanprall beispielhaft verwendet.
Antioxidative Effects of Flavonols and Their Glycosides against the Free‐Radical‐Induced Peroxidation of Linoleic Acid in Solution and in Micelles
Authors: Zhou Bo , Miao Qing , Yang Li , Liu Zhong‐Li 
Published: December 2004

AbstractThe antioxidative effect of flavonols and their glycosides against the peroxidation of linoleic acid has been studied in homogeneous solution (tBuOH/H2O, 3:2) and in sodium dodecyl sulfate and cetyl trimethylammonium bromide micelles. The peroxidation was initiated thermally by the water‐soluble initiator 2,2′‐azobis(2‐methylpropionamidine) dihydrochloride, and the reaction kinetics were studied by monitoring the formation of linoleic acid hydroperoxides. The synergistic antioxidant effect of the flavonols with α‐tocopherol (vitamin E) was also studied by following the decay kinetics of α‐tocopherol and the α‐tocopheroxyl radical. Kinetic analysis of the antioxidative process demonstrates that the flavonols are effective antioxidants in solution and in micelles, either alone or in combination with α‐tocopherol. The antioxidative action involves trapping the initiating radicals in solution or in the bulk‐water phase of the micelles, trapping the propagating lipid peroxyl radicals on the surface of the micelles, and regenerating α‐tocopherol by reducing the α‐tocopheroxyl radical. It was found that the antioxidant activity of the flavonols and their glycosides depends significantly on the position and number of the hydroxy groups, the oxidation potential of the molecule, and the reaction medium. The flavonols bearing ortho‐dihydroxy groups possess significantly higher antioxidative activity than those without such functionalities, and the glycosides are less active than their parent aglycones. The activity of the flavonols is higher in micelles than in solution, while the activity of α‐tocopherol is lower in micelles than in solution. This is because the predominant factor for controlling the activity is the hydrogen‐bonding interaction of the antioxidant with the micellar surface in the case of hydrophilic flavonols, while it is the inter‐ and intramicellar diffusion in the case of lipophilic α‐tocopherol.
Dissecting the Intimate Mechanism of Cyanation of {2Fe3S} Complexes Related to the Active Site of All‐Iron Hydrogenases by DFT Analysis of Energetics, Transition States, Intermediates and Products in the Carbonyl Substitution Pathway
Authors: Zampella Giuseppe , Bruschi Maurizio , Fantucci Piercarlo , Razavet Mathieu , Pickett Christopher J. , De Gioia Luca 
Published: December 2004

AbstractA bridging carbonyl intermediate with key structural elements of the diiron sub‐site of all‐iron hydrogenase has been experimentally observed in the CN/CO substitution pathway of the {2Fe3S} carbonyl precursor, [Fe2(CO)5{MeSCH2C(Me)(CH2S)2}]. Herein we have used density functional theory (DFT) to dissect the overall substitution pathway in terms of the energetics and the structures of transition states, intermediates and products. We show that the formation of bridging CO transitions states is explicitly involved in the intimate mechanism of dicyanation. The enhanced rate of monocyanation of {2Fe3S} over the {2Fe2S} species [Fe2(CO)6{CH2(CH2S)2}] is found to rest with the ability of the thioether ligand to both stabilise a μ‐CO transition state and act as a good leaving group. In contrast, the second cyanation step of the {2Fe3S} species is kinetically slower than for the {2Fe2S} monocyanide because the Fe2 atom is deactivated by coordination of the electron‐donating thioether group. In addition, hindered rotation and the reaction coordinate of the approaching CN− group, are other factors which explain reactivity differences in {2Fe2S} and {2Fe3S} systems. The intermediate species formed in the second cyanation step of {2Fe3S} species is a μ‐CO species, confirming the structural assignment made on the basis of FT‐IR data (S. J. George, Z. Cui, M. Razavet, C. J. Pickett, Chem. Eur. J. 2002, 8, 4037–4046). In support of this we find that computed and experimental IR frequencies of structurally characterised {2Fe3S} species and those of the bridging carbonyl intermediate are in excellent agreement. In a wider context, the study may provide some insight into the reactivity of dinuclear systems in which neighbouring group on‐off coordination plays a role in substitution pathways.
Synthesis and Structures of Cycloalkylidene‐Bridged Cyclopentadienyl Metallocene Catalysts: Effects of the Bridges of Ansa‐Metallocene Complexes on the Catalytic Activity for Ethylene Polymerization
Authors: Wang Baiquan , Mu Bin , Deng Xiaobin , Cui Huiling , Xu Shansheng , Zhou Xiuzhong , Zou Fenglou , Li Yang , Yang Ling , Li Yufei , Hu Youliang 
Published: December 2004

AbstractA series of cycloalkylidene‐bridged cyclopentadienyl metallocene complexes, [(CH2)nC(C5H4)2MCl2] (M = Ti, n = 4 (4), 5 (5), 6 (6); M = Zr, n = 4 (7), 5 (8), 6 (9); M = Hf, n = 4 (10), 5 (11), 6 (12)), have been synthesized and applied to ethylene polymerization after activation with methyl aluminoxane (MAO). The cycloalkylidene‐bridged titanocene catalysts exhibit much higher activities than the corresponding zirconocene and hafnocene analogues, and have the highest activities at higher temperatures. In comparison, the silacyclopentylidene‐bridged metallocene complexes [(CH2)4Si(C5H4)2MCl2] (M = Ti (13), Zr (14)) and isopropylene‐bridged metallocene complexes [Me2C(C5H4)2MCl2] (M = Ti (15), Zr (16)) have also been synthesized and applied to ethylene polymerization. In both cases, the titanocene complexes show much higher activities than the corresponding zirconocene analogues, especially at a lower temperature. The molecular structures of complexes 4–9 have been determined by X‐ray diffraction. The structure–activity relationships, especially the effects of the bridges of ansa‐metallocene complexes, are discussed.
Polyoxometalate‐Supported Y– and YbIII–Hydroxo/Oxo Clusters from Carbonate‐Assisted Hydrolysis
Authors: Fang Xikui , Anderson Travis M. , Benelli Cristiano , Hill Craig L. 
Published: December 2004

AbstractCarbonate‐assisted hydrolysis of Y or YbIII ions in the presence of the trivacant Wells–Dawson polyoxoanion, α‐[P2W15O56]12−, produced two polyoxometalate‐supported Y– or YbIII–hydroxo/oxo clusters, which have been characterized by single‐crystal X‐ray structure determination. The structure of the Y complex consists of a distorted Y4(OH)4 cubane cluster encapsulated by two lacunary α‐[P2W15O56]12− units, while the Yb cluster features a hexametallic core centered around a μ6‐oxo atom with each ${{\rm Yb}{{{\rm III}\hfill \atop 3\hfill}}}$ triangular face capped by an oxo or a hydroxo group. Magnetization measurements of the ytterbium(III) derivative suggested that intermolecular dipolar exchange is present at low temperatures (below 15 K). Despite its absence in the structures themselves, control experiments show that carbonate not only functions in the hydrolysis, it also influences the structure of the complexes by complexation to yttrium and the f‐block elements.
Mit Chromatographie und Spektrometer: Forensische Toxikologie
Authors: Wildemann Holger 
Published: December 2004

AbstractDie forensische Toxikologie befasst sich mit Alkohol‐, Drogen‐, Medikamentennachweisen sowie mit dem Nachweis anderer potentiell giftiger Substanzen und der Beurteilung deren Wirkung bei akuten Vergiftungen, Todesfällen und Straftaten. Als Untersuchungsmaterialen sind hierbei Blut, Serum, Urin, Mageninhalt und Haare von besonderer Bedeutung. Die Methodik der forensischen Toxikologie besteht hauptsächlich aus einem Repertoire physikalischer und chemischer Analyseprinzipien. Mittels immunologischer Testverfahren, die auf Antigen‐Antikörper‐Reaktionen basieren, können spezifisch verschiedene Stoffgruppen oder chemisch definierte Einzelsubstanzen in Körperflüssigkeiten schnell und einfach qualitativ nachgewiesen werden. Für quantitative Bestimmungen werden die Analyten angereichert und anschließend mittels GC/MS, LC/MS, HS/GC/FID oder HPLC/DAD aufgetrennt und detektiert.
Pionier der modernen Quantenchemie: Hans Hellmann
Authors: Jug Karl , Ertmer Wolfgang , Heidberg Joachim , Heinemann Manfred , Schwarz W. H. Eugen 
Published: December 2004

AbstractLeben und Werk Hans Hellmanns wurden gewürdigt. Hellmann überschritt die Grenzen von der Physik zur Chemie. Er entwickelte dabei neuartige Theoreme und Methoden zur Beschreibung der chemischen Bindungen und Reaktionen, die auch heute noch Bestand haben. Seine wissenschaftliche Klarsicht und sein persönliches Schicksal sollten uns leiten und mahnen.
Brennstoffzellen: Entwicklungsstand und Anwendungen
Authors: Reiche Annette , Haufe Stefan 
Published: December 2004

AbstractBrennstoffzellen haben das Potenzial, eine bedeutende Rolle in der zukünftigen Energieversorgung zu spielen. Ihre Einsatzmöglichkeiten erstrecken sich von mobilen Anwendungen über den Einsatz in der Hausenergieversorgung und der industriellen Kraft‐Wärme‐Kopplung bis hin zu Kleinstanwendungen, bei denen Brennstoffzellen als Batterie‐ und Akkuersatz für netzunabhängige Geräte dienen können. Der aktuelle Entwicklungsstand und Anwendungsmöglichkeiten werden für alle Typen von Brennstoffzellentypen dargestellt und die zugehörigen Kostenstrukturen diskutiert. Weiterhin wird ein Überblick über Verfahren zur Erzeugung bzw. Speicherung von Wasserstoff gegeben und Vorraussetzungen für eine Wasserstoffwirtschaft erörtert.
Karl Samuel Leberecht Hermann
Authors: Brandes Georg 
Published: December 2004

AbstractAls Apotheker, Chemiker und Unternehmer war er einer der Begründer der chemischen Industrie in Preußen. Als Praktiker hat er in Deutschland das Leblanc‐Soda‐Verfahren eingeführt, als Theoretiker das Cadmium entdeckt und als Unternehmer in Schönebeck eine der ältesten chemischen Fabriken errichtet.
Klebstoffe im Brennpunkt der Entwicklung
Authors: Borchard‐Tuch Claudia 
Published: December 2004

AbstractEin idealer Klebstoff sollte vielfältig einsetzbar und alterungsbeständig sein. Zudem muss er extremsten Anforderungen genügen und darf der Umwelt keinen Schaden zufügen. Inzwischen ist die Forschung diesem Wunschbild sehr nahe gekommen.
Fluid flow analysis by finite element method using arbitrarily deformed elements (Proposal of the GMSR‐method)
Authors: Matsuda Y. , Shao C. , Yoshino M. , Hoshihara M. , Tanaka Y. 
Published: December 2004

AbstractThe generalized MSR‐method (GMSR‐method) is proposed as a finite element fluid analysis algorithm for arbitrarily deformed elements using the error analysis approach. The MSR‐method was originally developed by one of the authors in our previous research works using a modified Galerkin method (MGM) for a convection–diffusion equation and the SIMPLER‐approach. In this paper, this MGM is developed theoretically in the case of arbitrarily deformed elements using the error analysis approach. In the GMSR‐method, since the inertia term and the pressure term are considered explicitly, only symmetrical matrices appear. Hence, it helps us reduce computational memory and computation time. Moreover, artificial viscosity and diffusivity are introduced through an error analysis approach to improve the accuracy and stability. This GMSR‐method is applied for two‐ and three‐dimensional natural convection problems in a cavity. In the computations at different Rayleigh numbers, it is shown that this method gives reasonable results compared to other research works. Thus, it is found that the GMSR‐method is applicable to thermal‐fluid flow problems with complicated boundaries. Copyright © 2004 John Wiley & Sons, Ltd.
Repeated injuries dramatically affect cells of the oligodendrocyte lineage: Effects of PDGF and NT‐3 in vitro
Authors: Fressinaud Catherine 
Published: December 2004

AbstractIn multiple sclerosis, relapses occur and remyelination is incomplete, whereas one demyelinating lesion induced by lysophosphatidyl choline (LPC) in rats is completely remyelinated; this process is accelerated by platelet‐derived growth factor (PDGF) (Allamargot et al.: Brain Res 918:28–39,2001) and neurotrophin‐3 (NT‐3) (Jean et al.: Brain Res 972:110–118,2003). Similarly, oligodendrocyte (OL) progenitors might not be depleted by two to three episodes of toxic demyelination (Penderis et al.: Brain 126:1382–1391,2003); nevertheless this does not allow conclusions about the fate of resident cells (mature OL). As myelinated fibers per OL are constantly decreased in chronic MS plaques (Fressinaud and Jean: J Neurochem 85(suppl):100,2003), this suggests that OL decreased capability to synthesize new myelin membranes could result from successive relapses, impairing thereby remyelination. Thus, we have determined the consequences of multiple versus unique (Fressinaud and Vallat: J Neurosci Res 38:202–213,1994) LPC treatments on newborn rat brain pure OL cultures, as well as the putative pro‐remyelinating effects of PDGF and of NT‐3 in these conditions. Split (0.5 · 10−5 M, 6 h × 4) and multiple (2 · 10−5 M, 24 h × 2) LPC doses induced more cell loss than a unique treatment (2 × 10−5 M, 24 h) and there was no recovery. OL progenitors (A2B5+ cells) and differentiated (CNP+) OL were drastically decreased. Moreover, mature (MBP+) OL disappeared from these cultures, indicating that mature OL are also vulnerable to multiple insults. PDGF, as well as NT‐3, induced at least partial recovery, and enhanced OL progenitor proliferation. In cultures treated with either of these growth factors, mature OL represented one‐fourth of cells and extended numerous ramified processes and putative myelin balls. © 2004 Wiley‐Liss, Inc.
Regulation of naturally occurring antisense RNA of myosin heavy chain (MyHC) in neonatal cardiomyocytes
Authors: Luther H.P. , Bartsch H. , Morano I. , Podlowski S. , Baumann G. 
Published: December 2004

AbstractNaturally occurring antisense RNA has been detected for a range of eukaryotic genes. Its abundance compared to levels of its complementary sense mRNA appears to be a factor indicating its possible regulatory function. In previous studies, we detected appreciable levels of antisense RNA against the two isoforms (α and β) of the heavy myosin‐chain (MyHC) in the myocardium of rats. If this is to play a significant role in gene expression antisense levels should vary in response to external and internal cellular influences. Recently, a bidirectional promoter located in the α/β MyHC intergenic region was described, which was proposed to regulate coordinated transcription of α‐MyHC sense and β‐MyHC antisense. To study MyHC antisense regulation in neonatal heart, we investigated cultivated myocytes stimulated with either trijodthyronin (T3) as an inductor of α‐MyHC or phenylephrine with stimulation of β‐MyHC. RNA‐quantification of sense and antisense transcripts of both isoforms was performed by real‐time RT‐PCR. Stimulation by T3 led to an induction of both sense and antisense of α‐MyHC and to a decrease of β‐MyHC sense and antisense. Phenylephrine increased sense and antisense β‐MyHC but reduced antisense α‐MyHC. The sense/antisense of α‐ and β‐MyHC ratio was unchanged compared to control. Results indicate a coregulation of sense and antisense MyHC RNA under stimulation of T3 and phenylephrine in neonatal cardiomyocytes. © 2004 Wiley‐Liss, Inc.