bluuebunny/crossref_metadata_2025_split huggingface dataset:
Standsicherheitsuntersuchung für ein räumliches Böschungssystem – Berechnung mit einem zusammengesetzten dreidimensionalen Bruchmechanismus und Modellversuch im Gelände – Teil 2: Durchführung der Berechnung und Ergebnisse
Authors: Goldscheider Michael , Lizcano‐Peláez Arcesio 
Published: July 2004

AbstractFür die Berechnung der Sicherheit gegen einen räumlichen Grabenbruch an einer hohen Randböschung eines Braunkohletagebaus wird ein räumlicher zusammengesetzter Starrkörperbruchmechanismus entwickelt und berechnet. Die Grundlagen und Grundgleichungen wurden in Teil 1 behandelt. Der Teil 2 beschreibt die Durchführung der Berechnung, die Optimierung des Bruchmechanismus und typische Berechnungsergebnisse.
Untersuchungen zum Einfluß natürlicher und künstlicher Bewitterung auf den Schubmodul von Verbund‐Sicherheitsglas
Authors: Ensslen Frank , Paschke Jens 
Published: July 2004

AbstractDas Tragverhalten von Verbund‐Sicherheitsgläsern (VSG) wird maßgeblich durch die Schubsteifigkeit des Zwischenschichtmaterials, i. d. R. Polyvinylbutyral (PVB), bestimmt. Neben den auf das Schubverhalten bekannten Einflüssen, wie Temperatur und Einwirkungsgeschwindigkeit, existieren je nach Anwendung im Freien oder innerhalb von Gebäuden klimatische, z. T. langandauernde Beanspruchungen für VSG. Da es sich bei PVB um einen polymeren Werkstoff handelt, lösen Klimalasten, wie z. B. UV‐Strahlung, Feuchte und schwankende Lufttemperatur usw., Alterungsvorgänge und somit chemische Veränderungen innerhalb des Polymermaterials aus.Zur Klärung der Alterungsbeständigkeit von VSG bzw. der Langzeitstabilität der Verbundwirkung anhand des Schubmoduls wurden experimentelle Untersuchungen an bewitterten bzw. gealterten Proben in Abhängigkeit der Belastungsgeschwindigkeit durchgeführt. Zum Vergleich stehen Versuchsergebnisse an neuen bzw. ungealterten VSG‐Elementen aus der gleichen Charge zur Verfügung.Die Versuche zeigten, daß VSG je nach Intensität der UV‐Strahlung und Umgebungstemperatur unterschiedlich resistent ist.Feuchtigkeit hingegen dringt über die Kanten in das Innere und führt unter Last zu Ablösungserscheinungen der PVB‐Folie im VSG‐Randbereich (ca. 50 mm Streifen).Die dieser Arbeit zugrundeliegenden experimentellen Versuche sind im Bereich Konstruktionsteilprüfung des Instituts für Konstruktiven Ingenieurbau der Ruhr‐Universität Bochum durchgeführt worden. Die Bereitstellung der Probekörper und wertvolle Informationen zu diesem Thema verdanken die Autoren Herrn Dr. Koll und Herrn Dr. Stenzel, HT TROPLAST AG, Troisdorf. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Meßtechnische Erfassung von Lage und Verformung eines Stahltragwerks unter Temperatureinfluß
Authors: Schulz Hans 
Published: July 2004

AbstractAn einem Abschnitt des stählernen Traggerüsts der Wuppertaler Schwebebahn wurden über einen längeren Zeitraum dreidimensionale geodätische Messungen durchgeführt, um die Verformungen von Stahlbauwerken unter Temperaturlast zu untersuchen. Aus einem genauen geodätischen Netz heraus wurden die Koordinaten von am Objekt vermarkten Punkten bei gleichzeitiger Erfassung der Stahltemperatur bestimmt. Ziele der Untersuchungen waren, die mit einem Standardmeßverfahren in der Praxis erreichbaren Meßunsicherheiten für Kontroll‐, Überwachungs‐ und Absteckungsvermessungen an komplexen Stahlkonstruktionen zu ermitteln und gleichzeitig zu überprüfen, ob sich die Konstruktion unter Temperaturlast dem Materialgesetz entsprechend verhält. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Zur Gelenkbildung in historischen Tragsystemen aus Mauerwerk
Authors: Jagfeld Matthias , Barthel Rainer 
Published: July 2004

AbstractDurch Experimente, numerische Berechnungen und analytische Untersuchungen kann gezeigt werden, daß in gemauerten Bauteilen aufgezwungene Rotationen zu wenigen, verhältnismäßig breiten Rissen führen. Je kleiner die inneren Druckkräfte in einem Bauteil sind, desto eher konzentrieren sich die Verdrehungen. In Gewölben, die oft nur ihr Eigengewicht abtragen, sind daher öfter einzelne breite Risse zu beobachten als in gemauerten Pfeilern, die i. d. R. wesentlich stärker beansprucht werden. Im Umkehrschluß lassen breite, einzelne Risse im Mauerwerk in erster Linie auf Bewegungen schließen und nicht auf Überlastungen. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bis(pyridine)iodonium Tetrafluoroborate (IPy2BF4): A Versatile Oxidizing Reagent
Authors: Barluenga José , González‐Bobes Francisco , Murguía Marcelo C. , Ananthoju Sreenivasa R. , González José M. 
Published: July 2004

AbstractThe use of bis(pyridine)iodonium tetrafluoroborate (IPy2BF4) as an oxidizing agent towards different types of alcohols is reported. The observed reactivity involves different reaction pathways, as a function both of the structures of the starting materials and of the experimental conditions. Interestingly, the title iodine‐containing compound is capable of a tuneable reaction with simple cycloalkanols, providing straight and selective access either to ω‐iodocarbonyl compounds or to ketones, a previously unreported and chemoselective range of oxidation potential. Furthermore, appropriate conditions for the preparation of aldehydes and esters from primary alcohols by easily performed experimental procedures were also established. The β‐scission reactions of cycloalkanols and the α‐oxidation processes of primary, secondary and benzylic alcohols are discussed.
NDP kinase moves into developing primary cilia
Authors: Mitchell Kimberly A. P. , Gallagher Betty C. , Szabo Gabor , de S. Otero Angela 
Published: July 2004

AbstractInmunofluorescence staining of murine NIH3T3 fibroblasts grown at high density shows that conventional nucleoside diphosphate (NDP) kinases A and B localize to a sensory organelle, the primary cilium. Similar results are obtained with Xenopus A6 kidney epithelial cells, suggesting that NDP kinases are a universal component of the primary cilium. The translocation of NDP kinase into primary cilia depends on size, taking place only when cilia reach a critical length of 5–6 μm. In mature cilia, NDP kinases are distributed along the ciliary shaft in a punctate pattern that is distinct from the continuous staining observed with acetylated α‐tubulin, a ciliary marker and axonemal component. Isolation of a fraction enriched in primary cilia from A6 cells led to the finding that ciliary NDP kinase is enzymatically active, and is associated with the membrane and the matrix, but not the axoneme. In contrast, acetylated α‐tubulin is found in the axoneme and, to a lesser extent, in the membrane. Based on the tightly regulated translocation process and the subciliary distribution pattern of NDP kinase, we propose that it plays a role in the elongation and maintenance of primary cilia by its ability to regenerate the GTP utilized by ciliary microtubule turnover and transmembrane signaling. Cell Motil. Cytoskeleton 59:62–73, 2004. © 2004 Wiley‐Liss, Inc.
Urinary and rectal complications of contemporary permanent transperineal brachytherapy for prostate carcinoma with or without external beam radiation therapy
Authors: Sarosdy Michael F. 
Published: July 2004

AbstractBACKGROUNDProstate brachytherapy is increasingly used to treat prostate carcinoma, alone or combined (combination therapy) with external beam radiation therapy (EBRT). This report cites the frequency and nature of urinary and rectal complications requiring unplanned interventions after contemporary brachytherapy with or without EBRT.METHODSA total of 177 consecutive patients underwent either brachytherapy (100 patients [56.5%]) or combination therapy (77 patients [43.5%]) for clinical T1‐2 prostate carcinoma between July 1998 and July 2000. All the patients were analyzed with regard to disease characteristics, treatment details, and complications requiring unplanned interventions in up to 48 months of follow‐up.RESULTSCatheter drainage for urinary retention was required for a median of 55 days (range, 3–330 days) in 36 patients (20%), including 24% after brachytherapy and 16% after combination therapy. Transurethral resection of the prostate (TURP) was performed at a median of 12 months (range, 8–18 months) after implantation in 5% of patients after brachytherapy and 14.5% of patients after combination therapy (P = 0.029). Colonoscopy with or without fulguration for rectal bleeding was performed in 37 of 158 patients (97 in the brachytherapy group and 61 in the combination therapy group) (23.4%) at a median of 17 months (range, 4–45 months), including 15 patients (15.5%) after brachytherapy and 22 patients (36%) after combination therapy (P = 0.002). Combination therapy resulted in fecal diversion in 6.6% of patients (P = 0.021), urinary diversion in 3.2% of patients (P = 0.148), and clean intermittent self‐catheterization for recurrent stricture after multiple TURPs in 4.9% of patients (P = 0.055), none of which occurred after brachytherapy. Overall, 20.6% of patients underwent TURP or colonoscopy after brachytherapy, whereas 44.2% underwent those or more extensive unplanned procedures after combination therapy (P = 0.001).CONCLUSIONSComplications requiring unplanned procedures may occur after brachytherapy, and may be increased significantly after brachytherapy combined with EBRT. These data reinforce the concept that quality assurance and technique are important in prostate brachytherapy, but, even when these are in place, complications can occur, especially when EBRT is added to brachytherapy. Cancer 2004. © 2004 American Cancer Society.
Initial treatment of melanoma brain metastases using gamma knife radiosurgery
Authors: Radbill Andrew E. , Fiveash John F. , Falkenberg Elizabeth T. , Guthrie Barton L. , Young Paul E. , Meleth Sreelatha , Markert James M. 
Published: July 2004

AbstractBACKGROUNDMelanoma is the primary malignancy that is most likely to metastasize to the brain. Because such an event carries an almost uniformly poor prognosis, the current study reviewed outcomes and identified associated prognostic indicators for 51 consecutive patients receiving gamma knife (GK) radiosurgery in the initial treatment of 188 intracranial melanoma metastases.METHODSData were collected retrospectively from a single‐center GK radiosurgery database and from primary patient medical records and radiographs.RESULTSAt presentation, 71% of patients had multiple intracranial metastases, and extracranial metastases were present in 66% of patients. Thirty‐two patients (63%) were initially treated with GK radiosurgery alone, whereas the remainder received GK radiosurgery in combination with surgery and/or whole‐brain radiotherapy (WBRT). Overall median survival from time of GK radiosurgery was 26 weeks. Subgroup analysis revealed a median survival of 77 weeks for patients presenting with a single lesion, compared with 20 weeks for patients presenting with multiple lesions (P = 0.003). Patients in recursive partitioning analysis (RPA) Class I survived a median of 57 weeks, compared with a median survival of 20 weeks for patients in RPA Class II or III (P = 0.002). Although long‐term imaging follow‐up revealed that a majority of patients experienced distant brain metastases, multivariate analysis showed that distant metastases occurred significantly sooner in patients with extracranial metastases (P = 0.0004). Addition of initial WBRT had no significant effect on the time to development of new brain metastases (P = 0.13). Local control (crude) was observed in 81% of lesions initially treated with GK. Patients experienced improved or stable symptoms for a median of 37 weeks post–GK radiosurgery.CONCLUSIONSSurvival analyses supported the use of GK radiosurgery in the initial treatment of patients with melanoma brain metastases, with best results occurring in patients presenting with a single lesion. Cancer 2004. © 2004 American Cancer Society.
Vascular endothelial growth factor C and vascular endothelial growth factor receptor 2 are related closely to the prognosis of patients with ovarian carcinoma
Authors: Nishida Naoyo , Yano Hirohisa , Komai Kan , Nishida Takashi , Kamura Toshiharu , Kojiro Masamichi 
Published: July 2004

AbstractBACKGROUNDThe vascular endothelial growth factor (VEGF) family and VEGF receptors (VEGFR) play an essential role in the angiogenesis of both pathologic and nonpathologic conditions. However, the prognostic significance of VEGF and VEGFR expression in ovarian carcinoma is unclear.METHODSThe tissue expression levels of VEGF‐A, VEGF‐C, VEGFR‐2, and VEGFR‐3 in 80 specimens of ovarian carcinoma were examined immnohistochemically. The results obtained were analyzed clinicopathologically.RESULTSVEGF‐A, VEGF‐C, VEGFR‐2, and VEGFR‐3 were expressed both in tumor cells and in adjacent endothelial cells of blood and lymph vessels. The tissue expressions of VEGF‐C and VEGFR‐2 were correlated significantly with tumor extension, including peritoneal metastases outside the pelvic cavity (P = 0.0010 and P = 0.0008, respectively), lymph node metastases (P = 0.0030 and P = 0.0018, respectively), and positive ascitic cytology (P = 0.025 and P = 0.0016, respectively). Conversely, there was no significant correlation between VEGF‐A and VEGFR‐3 expression and clinicopathologic features of ovarian carcinoma. Logistic regression analysis revealed that the expressions of VEGF‐C and VEGFR‐2 also were independent risk factors for peritoneal and lymph node metastases. Survival curves determined by the Kaplan–Meier method and in univariate analysis demonstrated that high expression levels of VEGF‐C and VEGFR‐2 were associated with the 5‐year survival rate. In multivariate analysis, high expression levels of VEGF‐C and VEGFR‐2 emerged as independent indicators for disease‐specific survival.CONCLUSIONSHigh tissue expression of VEGF‐C and VEGFR‐2 reflects the aggressiveness of the spread of tumor in ovarian carcinoma. Thus, both have predictive value for identifying high‐risk patients who have a poor prognosis. Cancer 2004. © 2004 American Cancer Society.
Hospital‐to‐hospital variation in lymph node detection after colorectal resection
Authors: Miller Eric A. , Woosley John , Martin Christopher F. , Sandler Robert S. 
Published: July 2004

AbstractBACKGROUNDBetter recovery of lymph nodes from colorectal carcinoma resection specimens has been shown to be associated with higher survival rates for patients with TNM Stage II and Stage III tumors. It is possible that inadequate lymph node recovery and/or assessment could contribute to disparities in survival, with particular variation according to hospital volume.METHODSData from a population‐based study that involved 33 counties in North Carolina and was conducted between April 1997 and April 2000 were available for the examination of variations in lymph node recovery and detection of positive lymph nodes according to self‐reported demographic characteristics and hospital volume. The study comprised 324 patients with T2–T3N0–N1M0 colon adenocarcinoma. Logistic regression was used to determine odds ratios (ORs) associated with the recovery of fewer than seven lymph nodes and ORs associated with the detection of a positive lymph node according to hospital volume and patient characteristics.RESULTSLow‐volume hospitals were more likely to recover < 7 lymph nodes compared with high‐ and medium‐volume hospitals (low‐volume vs. high‐volume: adjusted OR, 1.9; 95% confidence interval [CI], 0.8–4.6; low‐volume vs. medium‐volume: adjusted OR, 1.7; 95% CI, 0.7–4.5) and less likely to detect positive lymph nodes. After controlling for tumor characteristics, low‐volume hospitals were less than one‐half as likely to detect a positive lymph node (low‐volume vs. high‐volume: adjusted OR, 0.3; 95% CI, 0.1–0.8; low‐volume vs. medium‐volume: adjusted OR, 0.4; 95% CI, 0.1–1.2).CONCLUSIONSThe current study suggests that patients at low‐volume hospitals may have their tumors pathologically understaged more frequently compared with patients at high‐ and medium‐volume hospitals. Cancer 2004. © 2004 American Cancer Society.
Proportional delay differentiation provision by bandwidth adaptation of class‐based queue scheduling
Authors: Michalas Angelos , Louta Malamati , Fafali Paraskevi , Karetsos George , Loumos Vassilios 
Published: July 2004

AbstractSupporting quality of service (QoS) over the Internet is a very important issue and many mechanisms have already been devised or are under way towards achieving this goal. One of the most important approaches is the so‐called Differentiated Services (DiffServ) architecture, which provides a scalable mechanism for QoS support in a TCP/IP network. The main concept underlying DiffServ is the aggregation of traffic flows at an ingress (or egress) point of a network and the marking of the IP packets of each traffic flow according to several classification criteria. Diffserv is classified under two taxonomies: the absolute and the relative. In absolute DiffServ architecture, an admission control scheme is utilized to provide QoS as absolute bounds of specific QoS parameters. The relative DiffServ model offers also QoS guarantees per class but in reference to the guarantees given to the other classes defined. In this paper, relative proportional delay differentiation is achieved based on class‐based queueing (CBQ) scheduler. Specifically, the service rates allocated to the classes of a CBQ scheduler are frequently adjusted in order to obtain relative delay spacing among them. The model presented can also be exploited in order to meet absolute delay constraints in conjunction with relative delay differentiation provision. Simulation experiments verify that our model can attain relative as well as absolute delay differentiation provided that the preconditions posed are satisfied. Copyright © 2004 John Wiley & Sons, Ltd.
Early regeneration genes: Building a molecular profile for shared expression in cornea–lens transdifferentiation and hindlimb regeneration in Xenopus laevis
Authors: Wolfe Adam D. , Crimmins Gregory , Cameron Jo Ann , Henry Jonathan J. 
Published: July 2004

AbstractRecent studies in Xenopus laevis have begun to compare gene expression during regeneration with that of the original development of specific structures (e.g., the hindlimb and lens), while other studies have sought differences in gene expression between regeneration‐competent and regeneration‐incompetent stages. To determine whether there are any similarities between the regeneration of different structures, we have used a differential screen to seek shared early gene expression between hindlimb regeneration and cornea–lens transdifferentiation in the Xenopus tadpole. We have isolated 13 clones representing genes whose expression is up‐regulated within the first few days of both regenerating processes and which are not demonstrably up‐regulated in the context of basic wound healing. Furthermore, all of these genes also show prominent late embryonic expression. The expression patterns and putative identities of all 13 genes are presented, and a model is considered that allows us to characterize and profile important changes in gene expression, which might be shared among various regenerating and developmental systems. Developmental Dynamics 230:615–629, 2004. © 2004 Wiley‐Liss, Inc.
Measurement of the rear‐face temperature of metals struck by lightning long‐duration currents
Authors: Metwally I. A. , Heidler F. , Zischank W. 
Published: July 2004

AbstractThis paper presents an experimental investigation of the rear‐face temperature rise of different metals struck by lightning long‐duration currents on the front face. The experimental investigation simulates the heating effect of one current component of the natural lightning flashes that may strike in‐flight or landed aircraft and rockets; munitions and nuclear weapons; and storage/collection tanks and pipelines of the petroleum/gas industries. In the case of a lightning strike the rear‐face temperature rise must be less than certain limits to avoid catastrophic damage/accidents. A sophisticated high‐speed infrared camera, having an image frequency of 50 Hz and a temperature range up to 1200°C, is used to measure the rear‐face temperature profiles as a function of the coordinates and time. The results are interpreted in light of the optical observation of the arc motion, physical measurement of the spot diameter, and study of the energy balance at the cathode and anode spots. The results reveal that for constant charge transfer, lightning long‐duration currents having higher amplitudes give a higher rear‐face temperature rise and hence a higher risk of accidents. Both the maximum rear‐face core temperature and the front‐face spot diameter exponentially increase with the mean current amplitude. Moreover, the maximum rear‐face core temperature varies exponentially with the charge and linearly with the action integral. Current injection with positive polarity of the test electrode gives a lower rear‐face temperature for all metals used except for aluminium where the trend is reversed. Copyright © 2004 John Wiley & Sons, Ltd.
Fixed‐frequency active current controller and low‐sensitivity voltage regulator for a voltage‐sourced buck‐boost type rectifier
Authors: Pires V. Fernão , Silva J. Fernando , Pires A. J. 
Published: July 2004

AbstractWe present an active fixed‐frequency input current controller and a low‐sensitivity output voltage regulator for a voltage‐sourced buck‐boost type rectifier operating in the continuous current mode. The current controller enforces the input line current to track the desired sinusoidal waveform in phase with the input source voltage, ensuring a near‐unity power‐factor operation of the rectifier. The current control strategy actively shapes the input current allowing a near‐sinusoidal input current even with high variations in the DC inductor current. A low‐sensitivity output voltage regulator modulating the amplitude of the sinusoidal reference for the current controller is also proposed. Both the current controller and the voltage regulator are based on sliding‐mode theory. Experimental results are presented and the performance compared to that obtained using a conventional Proportional Integral (PI) output voltage controller. Copyright © 2004 John Wiley & Sons, Ltd.
Minimal radial basis function neural network based differential protection of power transformers
Authors: Moravej Zahra 
Published: July 2004

AbstractThis paper presents a new approach for the protection of power transformers using a Minimal Radial Basis Function Neural Network (MRBFNN). The minimal resource allocation network (M‐RAN) learning algorithm which is a sequential learning radial basis function neural network is shown to realize networks with far fewer hidden neurons with better or the same approximation/classification accuracy; without resorting to trial and error. The performance of this algorithm is compared with the Multilayer Feed‐forward Networks (MFNs).The number of training patterns and the training time are drastically reduced and significant accuracy is achieved in the classification of different events and detection of faults in power transformers using computer simulated tests. Copyright © 2004 John Wiley & Sons, Ltd.