bluuebunny/crossref_metadata_2025_split huggingface dataset:
Längskraftbeanspruchung von durchgehend geschweißten Schienen auf Brücken für Lastkombinationen
Authors: Ruge Peter , Trinks Carolin , Muncke Martin , Schmälzlin Gerd 
Published: July 2004

AbstractDie Längskraftbeanspruchung von durchgehend geschweißten Schienen auf Brücken für Lastkombinationen wird im DIN ‐Fachbericht 101, K.3.5, geregelt. Die Lastfälle werden jeweils einzeln für sich nichtlinear analysiert und anschließend durch Summation der Teil ergebnisse zur Gesamtlösung zusammengefaßt. Diese Näherung wird hier durch eine korrekte Kombination zunächst der Lastfälle Temperaturdehnung plus Bremsen ersetzt. Dabei erweist sich der Wechsel des Längsverschiebewiderstandes von unbelastetem zu belastetem Gleis infolge Zugüberfahrt als zusätzlicher Lastfall.
Nachweis des Aufbruchs der Baugrubensohle nach der neuen DIN 1054: 2003‐01
Authors: Hettler Achim , Stoll Christian 
Published: July 2004

AbstractNach der Einführung der neuen DIN 1054 im Januar 2003 ist eine Anpassung des Nachweises der Sicherheit gegen Aufbruch der Baugrubensohle an das Teil sicherheitskonzept notwendig geworden. Dabei wird auf das ursprüngliche Verfahren von Weißenbach zurückgegriffen, das sich in der Praxis bewährt hat, dem aber noch das Globalsicherheitskonzept zugrunde liegt. Die neue Vorgehensweise ist im Arbeitskreis Baugruben entwickelt worden und wird anhand von Beispielen erläutert.
Planarien: neue Tiere aus Stammzellen: Regeneration extrem
Authors: Peter Roland 
Published: July 2004

AbstractPlanarien, eine Gruppe frei lebender Plattwürmer
(Strudelwürmer oder Turbellarien), zeichnen sich durch ein extremes
Regenerationsvermögen aus und können aus winzigen
Körperfragmenten vollständige Tiere bilden. Diese Fähigkeit
hängt eng zusammen mit ungeschlechtlicher Fortpflanzung durch Querteilung
und beruht auf einer Gruppe teilungsfähiger Zellen
(“Neoblasten”), die sämtliche Gewebe hervorbringen können. Sie dienen auch der physiologischen Zellerneuerung und der Produktion von Keimzellen. Im Unterschied zu Säugetieren besitzen Plattwürmer keine von den Körperzellen getrennte Keimbahn. Höchstwahrscheinlich gehen alle Neoblasten aus Stammzellen hervor und sind selbst zum Teil Stammzellen. Diese Strategie der Zellerneuerung gibt es auch bei anderen Turbellarienordnungen und mit hoher Wahrscheinlichkeit bei allen Plattwürmern (Plathelminthes). Neue Untersuchungen haben Wege eröffnet, um unter den lichtmikroskopisch einander sehr ähnlichen Neoblasten verschiedene Typen zu unterscheiden. So sollten sich schließlich die eigentlichen Stammzellen identifizieren lassen. Diese dürften bemerkenswerte Ähnlichkeiten zu den somatischen Stammzellen von Säugetieren und Menschen aufweisen.
Matthias Jacob Schleiden
Authors: Irsch Wilhelm 
Published: July 2004

AbstractMatthias Jacob Schleiden (1804‐1881), der 23 Jahre an der Friedrich‐ Schiller‐Universität in Jena wirkte, gilt als Vater der Zellbiologie. Weniger bekannt ist, dass der rührige Botaniker die erste fruchtbare Zusammenarbeit zwischen der Universität und der örtlichen Industrie anregte. Dass er konsequent die darwinistische Neuinterpretation der Anthropologie verfocht und die wissenschaftliche Diskussion im 19. Jahrhundert entscheidend prägte, ist ebenfalls wenig bekannt und erforscht. Wissenschaftshistoriker der Universität Jena haben den 200. Geburtstag Schleidens zum Anlass genommen, um erstmalig in einer Gesamtausgabe seine anthropologischen Schriften zu publizieren.
Welche Gene machen den Menschen zum Menschen?
Authors: Kronberg Inge 
Published: July 2004

AbstractDie im Mai 2004 veröffentliche Sequenz von Chromosom 22 des Schimpansen erreicht erstmals eine Genauigkeit, die der Sequenzierung des menschlichen Genoms entspricht. Das „International Chimpanzee Chromosome 22 Consortium” hat sich zur Aufgabe gestellt, die Gene herauszufinden, die für die typischen Unterschiede zwischen Schimpanse und Mensch verantwortlich sind.
Chronic pain after open mesh and sutured repair of indirect inguinal hernia in young males
Authors:   Swedish Hernia Data Base the Danish Hernia Data Base, Bay-Nielsen M , Nilsson E , Nordin P , Kehlet H 
Published: August 2004

AbstractBackgroundChronic pain is common after herniorrhaphy, but the effect of surgical technique (mesh versus non-mesh repair) and the social consequences of the pain have not been established. The aim of this study was to analyse chronic postherniorrhaphy pain and its social consequences in young males operated on for an indirect inguinal hernia with a Lichtenstein mesh repair, Shouldice or Marcy (annulorrhaphy) repair.MethodsThis was a postal questionnaire study carried out within the Danish and Swedish Hernia Database Collaboration. Some 2612 patients responded (response rate 80·9 per cent), of whom 1250 had undergone a Lichtenstein, 630 a Shouldice and 732 a Marcy repair.ResultsChronic pain had been experienced within the previous month by 22·9 per cent of the patients who responded. There was an overall decrease in pain with time, from 29·7 per cent at 6–12 months to 18·1 per cent at 37–48 months after surgery, with no overall differences between the three types of repair. Pain was more common in patients younger than 40 years of age. Some 3·9 per cent of patients described the pain as moderate to severe and as frequent or constant. Of all patients with pain, 10·7 per cent experienced it as worse after than before surgery, and 56·6 per cent stated that it interfered with social activities.ConclusionChronic pain is common after primary inguinal hernia repair in young males, but there is no difference in the pain associated with open mesh and non-mesh repair.
Monosaccharides as Silicon Chelators: Pentacoordinate Bis(diolato)(phenyl)silicates with the cis‐Furanose Isomers of Common Pentoses and Hexoses
Authors: Klüfers Peter , Kopp Florian , Vogt Martin 
Published: July 2004

AbstractFive‐coordinate phenylsilicates are formed from the reaction of trimethoxy(phenyl)silane with monosaccharides in methanol in the presence of a stoichiometric amount of base. Five complexes have been isolated and characterized with two ketoses and three aldopentoses. The silicon central atom in [K([18]crown‐6)][PhSi(β‐D‐Fruf 2,3H−2)2]⋅MeOH (1, Fru=fructose) is part of two chelate rings, with the ligands being β‐D‐fructofuranose‐O 2,O 3 dianions. The β‐furanose isomer is best suited for silicon ligation because it exhibits a torsion angle close to 0° for the most acidic diol function, thus assuring a flat chelate ring. The same structural principles are also found in [K([18]crown‐6)][PhSi(β‐D‐Araf1,2H−2)2]⋅2 MeOH (2, Ara=arabinose), [K([18]crown‐6)][PhSi(α‐D‐Ribf1,2H−2)2] (3, Rib=ribose), [K([18]crown‐6)][PhSi(α‐D‐Xylf1,2H−2)2]⋅ acetone (4, Xyl=xylose), and [K([18]crown‐6)][PhSi(α‐D‐Rulf2,3H−2)2] (5, Rul=ribulose).
Supramolecular Motifs in s‐Block Metal‐Bound Sulfonated Monoazo Dyes, Part 1: Structural Class Controlled by Cation Type and Modulated by Sulfonate Aryl Ring Position
Authors: Kennedy Alan R. , Kirkhouse Jennifer B. A. , McCarney Karen M. , Puissegur Olivier , Smith W. Ewen , Staunton Edward , Teat Simon J. , Cherryman Julian C. , James Rachel 
Published: July 2004

AbstractThe solid‐state structures of 43 Li, Na, K, Rb, Mg, Ca and Ba salts of para‐ and meta‐sulfonated azo dyes have been examined and can be categorised into three structural classes. All form alternating organic and inorganic layers, however, the nature of the coordination network that forms these layers differs from class to class. The class of structure formed was found to be primarily governed by metal type, but can also be influenced by the nature and position of the organic substituents. Thus, for the para‐sulfonated azo dyes, Mg compounds form solvent‐separated ion‐pair solids; Ca, Ba and Li compounds form simple coordination networks based on metal–sulfonate bonding; and Na, K and Rb compounds form more complex, higher dimensional coordination networks. Compounds of meta‐sulfonated azo dyes follow a similar pattern, but here, Ca species may also form solvent‐separated ion‐pair solids. Significantly, this first attempt to classify such dyestuffs using the principles of supramolecular chemistry succeeds not only for the simple dyes used here as model compounds, but also for more complex molecules, similar to modern colourants.
NOP – Ein neues organischchemisches Grundpraktikum: Nachhaltigkeit per Internet
Authors: Ranke Johannes , König Burkhard , Diehlmann Achim , Kreisel Günter , Nüchter Matthias , Störmann Reinhold , Hopf Henning 
Published: July 2004

AbstractDas Neue und nachhaltigere Organisch‐chemische Praktikum
NOP nutzt die zusätzlichen Möglichkeiten, die eine Website im Vergleich zu einem konventionellen Laborpraktikum in Buchform hat, um angehenden Synthesechemikern ein breiteres Verständnis der durchgeführten Versuche zu vermitteln. Hierzu gehören Informationen zu analytischen Methoden, Hintergrundinformationen zu den eingesetzten und entstehenden Stoffen sowie Kennzahlen zur Bewertung von Stoff‐ und Energieeffizienz der Versuche. Nicht zuletzt wird dabei Hintergrundwissen zum Konzept der nachhaltigen Entwicklung für den Themenbereich Synthesechemie aufbereitet.
Ultraschnelle Elektronenkristallographie
Authors: Harrer Roswitha 
Published: July 2004

AbstractMit der ultraschnellen Elektronenkristallographie lassen sich neue Wege einer wahrlich “zeitaufgelösten” Chemie beschreiben. Atombewegungen von Hundertstel Ångström, Zeitfenster von Billionstel Sekunden ‐ die Grenzen, chemische Vorgänge zu beobachten, scheinen in eine andere Dimension gerückt.
Die Chemie der Lakritzschnecke — Teil 2
Authors: Roth Klaus 
Published: July 2004

AbstractIm letzten Heft verfolgten wir den Weg vom Süßholz (Glycyrrhiza glabra) bis zur Lakritzschnecke. Obwohl seit Jahrhunderten in der Volksmedizin bei Magenbeschwerden und Erkrankungen der oberen Luftwege bewährt, konnte der Wirkstoff der Lakritze, die Glycyrrhetinsäure [1], erst 1936 in reiner Form isoliert und charakterisiert werden. Die sich anschließende Strukturaufklärung war fast ein Alleingang von Leopold Ruzžička und seiner Arbeitsgruppe. Begleiten wir ihn auf seinem mühsamen Weg von der Summenformel C30H46O4 bis zur Strukturformel. Vergleichen wir dann, wie Chemiker heute die Struktur eines so komplexen Naturstoffs mit Hilfe spektroskopischer Methoden bestimmen.
Keramik und Metalle durch Spritzguss in Form gebracht
Authors: Borchard‐Tuch Claudia 
Published: July 2004

AbstractGeometrisch komplexe Bauteile aus Werkstoffen wie Keramik, Hartmetallen und Superlegierungen lassen sich durch Pulverspritzgießen herstellen – eine moderne Technologie, die aus dem klassischen Spritzguss für die Kunststoffverarbeitung entlehnt ist.
Radioaktive Spürhunde
Authors: Hübner Carl 
Published: July 2004

AbstractRadioaktive Isotope könnten neue Impulse in der Krebstherapie setzen. Gekoppelt an zielsichere Eiweiße finden sie ihren Weg direkt zu den Tumorzellen – und zerstören diese mit ihrer Strahlung. In diesem Jahr bekam das erste derartige Radioimmuntherapeutikum eine EU‐Zulassung.
Adult de novo acute myeloid leukemia with t(6;11)(q27;q23)
Authors: Blum William , Mrózek Krzysztof , Ruppert Amy S. , Carroll Andrew J. , Rao Kathleen W. , Pettenati Mark J. , Anastasi John , Larson Richard A. , Bloomfield Clara D. 
Published: July 2004

AbstractBACKGROUNDAcute myeloid leukemia (AML) with t(6;11)(q27;q23) is a well established but rare entity, and few studies have reported the full clinical, hematologic, and outcome data of patients with this disease.METHODSTo characterize the features of t(6;11) AML, the authors searched the Cancer and Leukemia Group B (CALGB) cytogenetic database comprising 2667 adults with newly diagnosed, de novo AML and identified 16 patients (0.6%) with t(6;11). A review of the literature identified 33 adults with de novo t(6;11) AML for whom survival data were available.RESULTSCALGB patients had a median age of 45 years (range, 22–65 years) and commonly presented with French–American–British (FAB) subtype M4 or M5 (81%). Gingival involvement at presentation was common (31%). All patients with gingival involvement had FAB M4. Compared with other patients with M4 AML in the CALGB database (n = 429), patients with M4 and t(6;11) (n = 7) had a higher frequency of gingival hypertrophy at presentation (71% vs. 17%, P = 0.003). Patients with t(6;11) were more likely to be African American (P = 0.02) and to die during induction (P = 0.03) than those without t(6;11). The complete response (CR) rate was 69% (11 of 16 patients), and CR duration was short (median, 9 months). The estimated probability of 2‐year survival was 13%. Both long‐term survivors received allogeneic stem cell transplantation. The estimated probability of 2‐year survival of patients reported in the literature was 15%.CONCLUSIONSAlthough the patient sample was small, the authors suggested that investigational approaches, including allogeneic transplantation, be considered for adults with t(6;11) AML. Cancer 2004. © 2004 American Cancer Society.
Cytokeratin‐positive cells in sentinel lymph nodes in breast cancer are not random events
Authors: King Tari A. , Ganaraj Archana , Fey Jane V. , Tan Lee K. , Hudis Clifford , Norton Larry , Cody Hiram S. , Borgen Patrick I. 
Published: July 2004

AbstractBACKGROUNDThe incidence of immunohistochemistry (IHC)‐detected epithelial cell displacement in sentinel lymph node (SLN) biopsy is unknown. In the current study, we address this question by examining the pattern of SLN involvement in patients undergoing prophylactic mastectomy (PM) at Memorial Sloan‐Kettering Cancer Center (New York, NY).METHODSBetween January 1999 and January 2003, 5275 patients underwent SLN biopsy. Unilateral or bilateral PM with SLN biopsy was performed in 143 (2.7%) patients, representing 163 PM cases.RESULTSOccult carcinoma was identified in 13 of 163 (8.0%) PM specimens. Two patients with occult invasive carcinoma had positive SLNs (hematoxylin and eosin). In the remaining 150 PM cases without occult carcinoma (130 patients), 89% underwent IHC analysis of the SLNs. Of these 130 patients, 43 (33%) had one or more prior biopsies in their “cancer‐free” breast, a median of 43 days (range, 3–314 days) before PM. A total of 310 SLNs were examined by IHC (mean, 2.3 lymph nodes per PM case). Only 1 of 130 (0.8%) patients without occult carcinoma had an IHC‐positive SLN. This patient had Stage IIIC carcinoma of the contralateral breast. IHC‐positive SLNs were not identified in any of the 43 patients with a history of prior biopsy. Therefore, only 1 IHC‐positive SLN was detected in 310 (0.3%) lymph nodes examined.CONCLUSIONSIHC‐positive cells in SLNs are rare in the absence of cancer and are not the result of previous breast instrumentation. Although the prognostic significance of IHC‐positive cells remains controversial, the current study suggests that they are not random events. Cancer 2004. © 2004 American Cancer Society.
Congestion control for multimedia applications in the wireless internet
Authors: Rakocevic Veselin 
Published: July 2004

AbstractThis paper provides a parallel review of two important issues for the next‐generation multimedia networking. Firstly, the emerging multimedia applications require a fresh approach to congestion control in the Internet. Currently, congestion control is performed by TCP; it is optimised for data traffic flows, which are inherently elastic. Audio and video traffic do not find the sudden rate fluctuations imposed by the TCP multiplicative‐decrease control algorithm optimal. The second important issue is the mobility support for multimedia applications. Wireless networks are characterized by a substantial packet loss due to the imperfection of the radio medium. This increased packet loss disturbs the foundation of TCP's loss‐based congestion control. This paper contributes to the ongoing discussion about the Internet congestion control by providing a parallel analysis of these two issues. The paper describes the main challenges, design guidelines, and existing proposals for the Internet congestion control, optimised for the multimedia traffic in the wireless network environment. Copyright © 2004 John Wiley & Sons, Ltd.
Epstein‐Barr virus nuclear antigen 1 evades direct immune recognition by CD4+ T helper cells
Authors: Mautner Josef , Pich Dagmar , Nimmerjahn Falk , Milosevic Slavoljub , Adhikary Dinesh , Christoph Heike , Witter Klaus , Bornkamm Georg W. , Hammerschmidt Wolfgang , Behrends Uta 
Published: July 2004

AbstractThe Epstein‐Barr virus (EBV) nuclear antigen 1 (EBNA1) is the only viral protein regularly expressed in EBV‐associated malignancies. Immune recognition of EBNA1 by CD8+ T cells is prevented by an internal glycine‐alanine repeat (GAr) which blocks proteasomal degradation. To test whether EBV‐infected cells could be recognized by T helper cells, human CD4+ T cell clones specific for EBNA1 were isolated from latently EBV‐infected individuals. These T cells, however, failed to recognize EBV‐positive target cells. To investigate whether endogenous presentation of EBNA1 epitopes on MHC class II was prevented by the GAr domain, a mutant EBV strain with an EBNA1 lacking the GAr (EBNA1ΔGA) was generated and used to establish an Epstein‐Barr virus‐immortalized lymphoblastoid B cell line (LCL). The EBNA1ΔGA LCL were not recognized by the EBNA1‐specific T cell clones either, indicating that the GAr domain does not mediate this effect. Immune recognition could be restored by overexpression of EBNA1, for which at least 60‐fold higher levels of both EBNA1 or EBNA1ΔGAr protein were required. These results demonstrate that EBNA1 evades direct recognition by CD4+ T helper cells, since its steady state level is below the threshold required for efficient presentation on MHC class II. These findings have important implications for the design of immunotherapeutic approaches to target EBV‐positive malignancies.
Complement inhibitor membrane cofactor protein (MCP; CD46) is constitutively shed from cancer cell membranes in vesicles and converted by a metalloproteinase to a functionally active soluble form
Authors: Hakulinen Juha , Junnikkala Sami , Sorsa Timo , Meri Seppo 
Published: July 2004

AbstractHuman cell‐surface protein CD46 protects cells from complement damage, regulates immune functions through signaling and acts as a receptor for certain pathogenic microbes. Multiple molecular weight isoforms of membrane bound CD46 are produced by alternative splicing of the CD46 mRNA in an area coding for the serine/threonine/proline‐rich region or for the cytoplasmic tail. We demonstrate that CD46 becomes proteolytically modified on cell membranes. We observed that tumor cells liberated intact 60–65 kDa forms of CD46 into the cell culture medium on the surface of vesicles with a diameter of 200 nm. Furthermore, soluble CD46 (55–60 kDa) containing the glycosylated STP‐region but lacking the hydrophobic transmembrane sequence and cytoplasmic domains was released from tumor cell membranes. The use of selective inhibitors indicated that CD46 release is due to specific cleavage by a metalloproteinase. Exposure of the cells to hydrogen peroxide (H2O2) or their detachment from the pericellular matrix increased the shedding of soluble CD46. Both vesicular and soluble forms of CD46 remained functional and promoted C3b cleavage by factor I. The results show that the functional activity of CD46 is not restricted to the tumor cell membranes but can be liberated in vesicles and by a metalloproteinase.
Fratricide of CD8+ cytotoxic T lymphocytes is dependent on cellular activation and perforin‐mediated killing
Authors: Su Michael Wei‐Chih , Pyarajan Saiju , Chang Jin‐Hong , Yu Chao‐Lan , Jin Yong‐Jiu , Stierhof York‐Dieter , Walden Peter , Burakoff Steven J. 
Published: July 2004

AbstractCD8+ CTL mediate the destruction of cells displaying foreign peptides in association with class I MHC molecules. Since CD8+ CTL themselves express class I MHC molecules, a phenomenon known as “fratricide” can be elicited by T cells presenting antigens to other CTL. To gain insight into this mechanism, fratricide was induced in a clone of class I‐restricted CD8+ CTL by incubating the T cells with their agonist ligand, an octamer peptide derived from chicken ovalbumin. Our results indicate that agonist peptide not only stimulates proliferation and cytolysis of CTL but also initiates signaling pathways that are pertinent to T cell activation, including the mobilization of transcription factors. Also consistent with T cell activation, fratricide induced the transcription and translation of the pro‐inflammatory cytokines TNF‐α and IFN‐γ. Finally, the essential role of perforin, as opposed to Fas/FasL, in fratricide was demonstrated by the selective inhibition of cytolysis with an inhibitor of the perforin pathway, the absence of FasL expression on T cells and the presence of lytic granules visible by electron microscopy. Collectively, these findings reveal that fratricide is mediated by T cell activation and perforin‐mediated cytolysis. These results may have implications for the regulation of CD8+ CTL in immune responses.
Inhibition of cell surface MHC class II expression by Salmonella
Authors: Mitchell Erin K. , Mastroeni Pietro , Kelly Adrian P. , Trowsdale John 
Published: July 2004

AbstractPeptide presentation by MHC molecules is an essential component of the adaptive immune response. To persist in a host, many pathogens have evolved strategies that interfere with MHC antigen‐presentation. We show that in human cells harboring intracellular Salmonella, MHC class II cell surface expression was substantially reduced. The effect was specific for MHC class II as expression of additional surface receptors remained unchanged. We investigated the underlying mechanism and showed that class II biosynthesis and peptide loading were unaffected by the presence of Salmonella; however, infection led to an intracellular accumulation of mature molecules. The intracellular class II colocalized with lysosome‐associated membrane protein‐1 and HLA‐DM but not with the Salmonella‐containing vacuole. Using Salmonella mutants defective in different components and effectors of the Salmonella pathogenicity island‐2 type‐III secretion system, we traced the effect on class II to the sifA locus. SifA has been shown to be involved in recruiting membrane for the Salmonella‐containing vacuoles. Our data suggest an additional role for SifA in interfering with MHC class II antigen‐presentation.
Characterisation of Fuel Cell Membranes as a Function of Drying by Means of Contact Angle Measurements
Authors: Brack H.‐P. , Slaski M. , Gubler L. , Scherer G.G. , Alkan S. , Wokaun A. 
Published: July 2004

AbstractIn another paper in this volume, it is demonstrated that the electrochemical interface in MEAs, and thus the polarization performance of the resulting fuel cells, can be improved by optimising the hot‐pressing procedure in the MEA preparation. In particular, the extent of drying of the membrane during MEA preparation was shown to be critical. In the present investigation, the effect of the drying process, and thus water content, on the hydrophilicity, wetting, and surface energies of some fuel cell membranes is examined. Wetting and surface energies are well known to influence the bonding behaviour of materials. Conclusions about how membrane drying and changes in water content influence membrane bonding and the relative importance of these surface effects are drawn.