bluuebunny/crossref_metadata_2025_split huggingface dataset:
ZnO films deposited by optimized PLD technique with bias voltages
Authors: Yamaguchi Hiroyuki , Shitara Tamae , Komiyama Takao , Chonan Yasunori , Aoyama Takashi 
Published: December 2009

AbstractThe pulsed laser deposition (PLD) technique with bias voltage application for formation of high quality ZnO films was investigated. Oxygen ambient in the PLD chamber significantly decreased the photoluminescence (PL) intensity of near band edge (NBE) emission. Then, instead of using oxygen ambient, the PLD technique with bias voltage application was optimized to attain the stoichiometric composition of the ZnO films. As the deposition temperature was increased, the X‐ray spectrum width diffracted from the (0002) planes was decreased and it showed a minimum value at 700 °C. The PL intensity of the NBE emission also had its maximum value for the film deposited at 700 °C. For the ZnO films deposited at 700 °C, the X‐ray spectrum width showed the minimum value under a bias voltage of –50 V. The PL intensity of the NBE emission also had a maximum value under the same bias voltage. Thus, ZnO films deposited under a bias voltage of –50 V at 700 °C had strong NBE emission intensities. These results could be explained not only by attaining the stoichiometric composition of the ZnO film but also by decreasing the number of high energy O2– ions which caused non‐radiative recombination centers in the film. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Improvement of sol‐gel ZnO heterojunctions by hydrogen annealing
Authors: Abe Kazunori , Komiyama Takao , Chonan Yasunori , Yamaguchi Hiroyuki , Aoyama Takashi 
Published: December 2009

AbstractZnO films were formed quartz substrates and silicon (100) wafers by a sol‐gel technique, and they were crystallized (in air at 800 °C) and annealed in hydrogen (at 220 to 420 °C, for 10 to 120 min). Photoluminescence (PL) measurements of ZnO films on quartz substrates indicated that hydrogen annealing increased the near band edge (NBE) emission ten‐fold, but it only slightly decreased the deep level emission (DLE). Hall effect measurements showed an n‐type conduction of the films, with an electron concentration of about 1016 cm–3, Hall mobility of about 14 cm2/Vs, and resistivity of about 2 Ωcm. Before hydrogen annealing, n‐ZnO/p‐Si heterojunctions showed only ohmic behavio. After hydrogen annealing, however, the forward current was increased and the reverse current was decreased, and the final I‐V curve showed a typical rectifying characteristicc. These results can be explained by a conventional polycrystalline and grain boundary (GB) model with a potential barrier height near the GBs and defects in the grains. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Confirmatory analysis for phase III population pharmacokinetics
Authors: Hu Chuanpu , Zhang Ji , Zhou Honghui 
Published: December 2009

AbstractPopulation pharmacokinetics (POPPK) has many important uses at various stages of drug development and approval. At the phase III stage, one of the major uses of POPPK is to identify covariate influences on human pharmacokinetics, which is important for potential dose adjustment and drug labeling. One common analysis approach is nonlinear mixed‐effect modeling, which typically involves time‐consuming extensive search for best fits among a large number of possible models. We propose that the analysis goal can be better achieved with a more standard confirmatory statistical analysis approach, which uses a prespecified primary analysis and additional sensitivity analyses. We illustrate this approach using a phase III study data set and compare the result with that calculated using the common exploratory approach. We argue that the confirmatory approach not only substantially reduces analysis time but also yields more accurate and interpretable results. Some aspects of this confirmatory approach may also be extended to data analysis in earlier stages of clinical drug development, i.e. phase II and phase I. Copyright © 2009 John Wiley & Sons, Ltd.
β‐secretase inhibitory effects of furanocoumarins from the root of Angelica dahurica
Authors: Marumoto Shinsuke , Miyazawa Mitsuo 
Published: December 2009

AbstractIn the course of screening antidementia agents from natural products, five β‐secretase (BACE1) inhibitors were isolated from the root extract of Angelica dahurica (Umbelliferae). They were identified as furanocoumarins, isoimperatorin (1), imperatorin (2), (+)‐oxypeucedanin (3), (+)‐byakangelicol (4) and (+)‐byakangelicin (5). Among them, compounds 2 and 4 showed significant inhibitory activity against β‐secretase (BACE1) with IC50 values of 91.8 ± 7.5 and 104.9 ± 2.4 μM, respectively. Compounds 1‐5 inhibited BACE1 activity in a dose‐dependent manner. Copyright © 2009 John Wiley & Sons, Ltd.
Cornin ameliorates cerebral infarction in rats by antioxidant action and stabilization of mitochondrial function
Authors: Jiang Wang‐Lin , Zhang Shu‐Ping , Zhu Hai‐Bo , Jian‐Hou  , Tian Jing‐Wei 
Published: December 2009

AbstractThis study was conducted to investigate the efficacy of cornin, an iridoid glycoside, in an experimental cerebral ischemia induced by middle cerebral artery occlusion (MCAO) and reperfusion (I/R), and to elucidate the potential mechanism. Adult male Sprague‐Dawley rats were subjected to MCAO for 1 h, then reperfusion for 23 h. Behavioral tests were used to evaluate the damage to central nervous system. The cerebral infarct volume and histopathological damage were assessed to evaluate the brain pathophysiological changes. Spectrophotometric assay methods were used to determine the activities of superoxide dismutase (SOD) and glutathione‐peroxidase (GPx). Contents of malondialdehyde (MDA), the generation of reactive oxygen species (ROS) as well as respiratory control ratio and respiratory enzymes of the brain mitochondria were also determined. The results showed that cornin significantly decreased neurological deficit scores, and reduced cerebral infarct volume and degenerative neurons. Meanwhile, cornin significantly increased the brain ATP content, improved mitochondrial energy metabolism, inhibited the elevation of MDA content and ROS generation, and attenuated the decrease of SOD and GPx activities in brain mitochondria. These findings indicate that cornin has protective potential against cerebral ischemia injury and its protective effects may be due to amelioration of cerebral mitochondrial function and its antioxidant property. Copyright © 2009 John Wiley & Sons, Ltd.
Four carotenoids from Pittosporum tobira protect primary cultured rat cortical cells from glutamate‐induced toxicity
Authors: Moon Hyung‐In , Park Won‐Hwan 
Published: December 2009

AbstractWe observed that an aqueous extract of this medicinal plant exhibited significant neuroprotection against glutamate‐induced toxicity in primary cultured rat cortical cells from methanol extracts of the seeds of P. tobira. To further clarify the underlying neuroprotective mechanism(s) of this observed effect, we isolated and identified various active fractions and components. By using such fractionation procedures, four known carotenoids compounds – tobiraxanthins A1, A2, A3, and B – were isolated from the n‐hexane fraction of methanol extracts from the seeds of P. tobira. Among these four compounds, tobiraxanthins B exhibited significant neuroprotective activity against glutamate‐induced neurotoxicity, as indicated by a cell viability of approximately 50%, at concentrations ranging from 0.1 μM to 10 μM. These findings indicate that, the neuroprotective effects of P. tobira might be due to the inhibition of glutamate‐induced toxicity by carotenoids present in the plant. Copyright © 2009 John Wiley & Sons, Ltd.
Crocetin inhibits cell cycle G1/S transition through suppressing cyclin D1 and elevating p27kip1 in vascular smooth muscle cells
Authors: Zhou Cheng‐Hua , Xiang Min , He Shu‐Ying , Qian Zhi‐Yu 
Published: December 2009

AbstractCrocetin is a natural carotenoid compound isolated from Gardenia jasminoids Ellis. Our previous study shows that crocetin inhibits angiotensin II (Ang II)‐induced vascular smooth muscle cells (VSMCs) proliferation. To further explore the mechanism by which crocetin inhibits VSMCs proliferation, in the present study we examined the effect of crocetin on cell cycle progression and cell cycle regulatory proteins. Flow cytometry analysis showed that Ang II elicited significant increase in the percentage of VSMCs in the S phase, with a concomitant decline in the percentage of VSMCs in the G0/G1 phase. However, on pretreatment of VSMCs with crocetin, the percentage of VSMCs in the S phase decreased, while that in the G0/G1 phase increased significantly. In addition, Ang II‐induced increase of cell proliferation index was also decreased by crocetin. Western blotting analysis indicated that crocetin markedly inhibited the protein expression of cyclin D1 but not cyclin E. Crocetin also increased the level of cyclin‐dependent kinase inhibitor (CDKI) p27kip1 but not CDKI p21waf1/cip1. In conclusion, our present results suggest that the inhibition of cell cycle G1/S transition in VSMCs by crocetin can be attributed, at least in part, to its suppression of cyclin D1 and elevation of CDKI p27kip1. Copyright © 2009 John Wiley & Sons, Ltd.
Pharmacokinetics of bilobalide, ginkgolide A and B after administration of three different Ginkgo biloba L. preparations in humans
Authors: Woelkart Karin , Feizlmayr Elisabeth , Dittrich Peter , Beubler Eckhard , Pinl Fritz , Suter Andy , Bauer Rudolf 
Published: December 2009

AbstractA sensitive LC‐ESI‐MS method with a solid‐phase extraction was established for the determination of bilobalide, ginkgolide A and ginkgolide B in human plasma; bioavailability and pharmacokinetics of three different Ginkgo biloba L. preparations have been investigated. The preparations used in the present single‐dose pharmacokinetic study were different formulations of Ginkgo biloba L. extracts (Geriaforce™ tincture, new Ginkgo fresh plant extract tablets and EGb 761™) with various excipients. The analysis of Ginkgo terpene lactones was performed by LC‐MS on a Zorbax® SB‐C18 column. The mobile phase consisted of water + 0.1% acetic acid and methanol 68/32 (v/v) to 49/51 (v/v) at a flow rate of 200 μL/min. Bilobalide, ginkgolide A and ginkgolide B were monitored using the selected‐ion monitoring (SIM) mode at m/z of 325, 453 and 423, respectively.The amounts of the active compounds (terpene lactones) in the administered products were in the low‐mg range per dose. The assay method was successfully applied to the study of the pharmacokinetics and bioavailability of bilobalide, gingkolide A and ginkgolide B in humans. The resulting maximum concentrations (median) of bilobalide, ginkgolide A and ginkgolide B in plasma after administration of the maximum daily dose of the different Ginkgo products were 3.53, 3.62, and 1.38 ng/mL respectively after administration of Geriaforce™ tincture; 11.68, 7.36, and 4.18 ng/mL, respectively after taking Ginkgo fresh plant extract tablets; and 26.85, 16.44, 9.99 ng/mL, respectively after administration of EGb 761™ tablets. These data are relevant to demonstrate relative bioavailabilities of different Ginkgo biloba L. preparations (Geriaforce™ tincture, new Ginkgo fresh plant extract tablets and EGb 761™). Copyright © 2009 John Wiley & Sons, Ltd.
Effect of taxifolin glycoside on atopic dermatitis‐like skin lesions in NC/Nga mice
Authors: Ahn Ji Young , Choi Sun Eun , Jeong Mi Sook , Park Kwan Hee , Moon Nam Ju , Joo Seong Soo , Lee Chung Soo , Choi Young Wook , Li Kapsok , Lee Mi‐Kyung , Lee Min Won , Seo Seong Jun 
Published: December 2009

AbstractIncreased levels of eosinphils, IgE, IL‐4, 5, and 13 and pro‐inflammatory factors (COX‐2, iNOS) are observed in patients with atopic dermatitis (AD). Taxifolin 3‐O‐β‐D‐glucopyranoside (TAX) from the roots of Rhododendron mucronulatum (RM) was examined to determine whether its immunomodulatory effect was applicable for treating atopic dermatitis.A total of 7 groups of NC/Nga mice with AD were treated by topical application or intraperitoneal injection of TAX for 4 weeks. Follow‐up evaluations were done to assess the changes in clinical observations, eosinophil counts, and levels of IgE, cytokines, COX‐2 and iNOS.In the clinical observation during the experimental period, TAX treatment significantly reduced the severity of AD‐like lesions induced in NC/Nga mice. Eosinophil and IgE levels decreased after treatment of the animals with TAX. TAX may thus be associated with improvement of eosinophil‐related allergic diseases. The expression of cytokines (IL‐4, 5 and 13) was significantly inhibited in the TAX‐treated group, suggesting that TAX might play an immunoregulatory role associated with AD. In RT‐PCR, iNOS and COX‐2 expression levels were reduced in the TAX‐treated group. In western blotting, the expression levels of iNOS and COX‐2 were also reduced in the TAX‐treated group.These findings suggest that TAX is effective for the treatment of AD by preventing the production of inflammatory cytokines and by reducing skin inflammation. Copyright © 2009 John Wiley & Sons, Ltd.
Antihepatotoxic activity ofSaussurea lappaextract on D‐galactosamine and lipopolysaccharide‐induced hepatitis in mice
Authors: Yaeesh Sheikh , Jamal Qamar , Shah Abdul Jabbar , Gilani Anwarul Hassan 
Published: December 2009

AbstractThe effects of aqueous‐methanol extract ofSaussurea lappa Clarkeroot (Sl.Cr) was investigated against D‐galactosamine (D‐GalN) and lipopolysaccharide (LPS)‐induced hepatitis in mice. Co‐administration of D‐GalN (700 mg/kg) and LPS (1 μg/kg) significantly raised the plasma transaminase levels (ALT/AST) as compared to the control group (p< 0.05). Pretreatment of mice with different doses of Sl.Cr (150, 300 and 600 mg/kg) significantly prevented the D‐GalN and LPS‐induced rise in plasma levels of ALT and AST in a dose‐dependent manner (p< 0.05). Post‐treatment with Sl.Cr (600 mg/kg) significantly restricted the progression of hepatic damage induced by D‐GalN and LPS (p< 0.05). The improvement in plasma enzyme levels was further verified by histopathology of the liver, which showed improved architecture, absence of parenchyma congestion, decreased cellular swelling and apoptotic cells in treatment groups as compared to the toxin group of animals. These data indicate that the Sl.Cr exhibits hepatoprotective effect in mice and this study rationalize the traditional use of this plant in liver disorders. Copyright © 2009 John Wiley & Sons, Ltd.
Lycopene protects the structure of the small intestine against gamma‐radiation‐induced oxidative stress
Authors: Saada Helen N. , Rezk Renée G. , Eltahawy Noaman A. 
Published: December 2009

AbstractThe small intestine displays numerous morphological and functional alterations after exposure to ionizing radiations. Oxidative stress and changes in monoamines levels may contribute toward some of these alterations. The objective of the current work is to evaluate the efficacy of lycopene on radiation‐induced damage in the small intestine. Lycopene (5 mg/kg BW) was given to male albino rats, via gavages for 7 days before whole body exposure to gamma ray (6 Gy). Irradiated animals, sacrificed 7 days after irradiation, showed sloughing villi, ulcers, and ruptured goblet cells, shrinkage of submucosa layers, more fibers and fibroblasts. Histopathological changes were associated with a significant increase in thiobarbituric acid reactive substances (TBARS) and alteration in xanthine oxidoreductase system (XOR). In parallel, significant decreases in reduced glutathione (GSH) content, superoxide dismutase (SOD) and catalase (CAT) activities were recorded. Gamma irradiation has also induced a significant decrease in the level of monoamines: serotonin (5‐HT), dopamine (DA), norepinephrine (NE), and epinephrine (EPI) associated with an increase in monoamine‐oxidase (MAO) activity. Lycopene pretreatment has significantly improved the oxidant/antioxidant status, which was associated with significant regeneration of the small intestine, and improved monoamines levels. Based on these results, it is concluded that lycopene may protect the small intestine against radiation‐induced damage. Copyright © 2009 John Wiley & Sons, Ltd.
Output feedback stabilization for discrete singular systems with random abrupt changes
Authors: Wu Zhengguang , Su Hongye , Chu Jian 
Published: December 2009

AbstractThe problem of static output feedback control is investigated for discrete singular systems with Markovian jump. Two necessary and sufficient conditions for the discrete singular Markovian jump system to be regular, causal and stochastically stable are proposed in terms of linear matrix inequality (LMI) approach. Two kinds of design methods of the desired mode‐independent static output feedback controller are given. The explicit expressions for the desired controller are also given. Numerical examples are proposed to show the validness of the developed results. Copyright © 2009 John Wiley & Sons, Ltd.
A study of undergraduate physics students' understanding of heat conduction based on mental model theory and an ontology–process analysis
Authors: Chiou Guo‐Li , Anderson O. Roger 
Published: December 2009

AbstractThis study first used a new approach, combining students' ontological beliefs and process explanations, to represent students' mental models of heat conduction and then examined the relationships between their mental models and their predictions. Clinical interviews were conducted to probe 30 undergraduate physics students' mental models and their predictions about heat conduction. This study adopted a constant comparative method to discover patterns of the participants' responses across the various sources of data, such as verbal utterances, writings, and drawings. The results indicate that, based on the identified five process analogies for how heat is conducted and three ontological beliefs about the material basis for heat conduction, the combinations of these two aspects can better represent their mental models in terms of both the underlying mechanisms and emergent processes of heat conduction than using either alone as has sometimes been done in prior research. In addition, while a scientifically accepted mental model had a better chance to be accompanied by a correct prediction, a correct prediction might not result from a scientifically accepted mental model. However, as suggested by some cognitive psychologists, regardless of which mental models the participants possessed, they tended to automatically retrieve their learned rules or past experience, instead of manipulating their mental models, to generate predictions for the encountered problems. © 2009 Wiley Periodicals, Inc. Sci Ed 94:825–854, 2009
Numerische Schweißsimulation gekoppelt mit einem anschließenden Hämmerprozess und integrierten lokalen Ermüdungsberechnungen
Authors: Schaumann Peter , Keindorf Christian 
Published: December 2009

AbstractMit einem hochfrequenten Hämmerverfahren kann die Ermüdungsfestigkeit der Schweißnähte grundsätzlich nur gesteigert werden, wenn die Nahtübergänge dafür maßgebend sind. Zum Beispiel ergibt sich bei einseitig geschweißten Stumpfstößen keine signifikante Steigerung der Lebensdauer, weil sich die ermüdungskritische Stelle an die unbehandelte Nahtwurzel verlagert. Im vorliegenden Beitrag wird über Ergebnisse von experimentellen und numerischen Untersuchungen an un‐ und nachbehandelten Schweißverbindungen berichtet. Die Experimente erfolgten an stumpf geschweißten Stahlblechen, die anschließend an den Nahtübergängen mit einem hochfrequenten Hämmerverfahren nachbehandelt wurden. Die Schweißversuche dienten ferner als Verifikation für numerische Schweißsimulationen, die mit einem Hämmerprozess gekoppelt wurden. Ziel der Untersuchungen war es, die Effekte des Hämmerns zu erfassen, um hinsichtlich der Lebensdauer den Unterschied zwischen un‐ und nachbehandelten Schweißverbindungen numerisch aufzuzeigen. Dafür wurden das Kerbdehnungs‐ und Rissfortschrittskonzept in die Schweißsimulation implementiert, womit lokale Ermüdungsberechnungen im FE‐Modell möglich waren. Letztendlich liegen als Ergebnis nicht nur Spannungsplots, sondern auch Ermüdungsplots für die gesamte Schweißkonstruktion unter Berücksichtigung der Effekte des Schweißens und Hämmerns vor.Numerical welding simulation coupled with a hammer peening procedure and local fatigue assessments.Due to the post weld treatment the fatigue strength of welded joints can be enhanced in principal, if the weld toes are the most critical hot spots. But the fatigue life can not be increased significantly when the crack initiation starts at the untreated weld root. This paper provides detailed information about experimental and numerical investigations of an arc welding process followed by a process of hammer peening. The experiments were carried out on steel plates with single side butt welds. After welding the weld toes were treated by highfrequency hammer peening. However, the welding and fatigue tests were used as verifications for numerical welding simulations coupled with a hammer peening procedure and local fatigue calculations. The objective was to analyze the difference in fatigue strength between as welded and treated conditions. Therefore the change of residual stresses and notch geometry are the most important effects on the fatigue life for welded joints with and without post weld treatment. Within a fatigue tool the residual stresses and geometry of the notch can be considered in numerical simulations with local fatigue approaches. The total fatigue life was assessed by adding crack initiation life calculated with notch strain approach and crack propagation life calculated with crack propagation approach. Finally the coupled simulation provides not only stress plots but also fatigue plots for the whole welded joint under consideration of as welded and treated conditions after hammer peening.
Abminderungsfaktoren für das Biegedrillknicken von Walzprofilen – Grundsätzliches
Authors: Kindmann Rolf , Beier‐Tertel Judith 
Published: December 2009

AbstractDer Nachweis ausreichender Tragfähigkeit wird bei biegedrillknickgefährdeten Trägern in der Regel mit Hilfe von Abminderungsfaktoren geführt. Die Werte nach DIN 18800‐2 und DIN EN 1993‐1‐1 (EC 3) stimmen nicht überein, sondern weisen bereichsweise große Unterschiede auf. Zur Klärung des Sachverhalts werden für ausgewählte Basissysteme genaue Abminderungsfaktoren nach der Fließzonentheorie berechnet. Dabei zeigt sich, dass vergleichbare Werte in Abhängigkeit von der Querschnittsgeometrie um bis zu 32 % streuen. Als Parameter, mit dem die Profilabhängigkeit erfasst werden kann, wird das Verhältnis ly/IT identifiziert. Auf Grundlage dieser Erkenntnisse wird die Genauigkeit der Abminderungsfaktoren in den genannten Vorschriften beurteilt und festgestellt, dass eine Anpassung an den aktuellen Erkenntnisstand erforderlich ist.Reduction factors for lateral torsional buckling of hot rolled profiles – fundamentals.The resistance of members endangered by lateral torsional buckling is usually verified using reduction factors. The values of DIN 18800‐2 and DIN EN 1993‐1‐1 (EC 3) do not match and partly show big differences. For a clarification of this issue the reduction factors of selected basic structural systems are being determined according to the plastic zones theory. It can be recognized that corresponding values differ up to 32 % depending on the cross‐section geometry. The ratio ly/IT is being identified as a parameter covering the dependency of the crosssection. On this basis the reduction factor accuracy of the standards mentioned previously is being analysed with the conclusion, that an adjustment to the current state of knowledge is necessary.