bluuebunny/crossref_metadata_2025_split huggingface dataset:
Im Schatten eines Moleküls. Extinktionsmessung an einzelnen Quantensystemen
Authors: Gerhardt Ilja , Wrigge Gert 
Published: June 2009

AbstractDas Phänomen ist alltäglich: Licht durchläuft ein optisches Medium und wird dabei abgeschwächt. Der Effekt heißt Extinktion. Zu dieser “Auslöschung” tragen zwei Mechanismen bei: Streuung und Absorption. Dabei ist besonders die Frage interessant, welchen “Schatten” einzelne Quantensysteme wie Atome oder Moleküle werfen. Inzwischen gelingt es, experimentell in diesen Größenbereich vorzudringen. Die Streuung am System ist dabei entscheidend: Die destruktive Interferenz zwischen einfallendem und gestreutem Licht kann das einfallende Licht in Ausbreitungsrichtung sogar vollständig auslöschen. Ob auch im Experiment ein einzelnes Atom zu dieser vollständigen Auslöschung fähig ist, gehört zu den noch offenen Fragen. Das Forschungsgebiet hat zudem für die Quanteninformationsverarbeitung Bedeutung. Diese benötigt eine möglichst effiziente Kopplung eines Lichtfeldes an ein einzelnes Quantensystem.
Neues Radon‐Isotop entdeckt
Authors: Schweikhard Lutz , Neidherr Dennis , Blaum Klaus 
Published: June 2009

AbstractMit Penning‐Ionenfallen lassen sich kurzlebige Radionuklide speichern und ihre Massen mit höchster Genauigkeit bestimmen. Die präzisen Massenwerte gehen in Kernstruktur‐Untersuchungen und Tests der fundamentalen Wechselwirkungen sowie in die Modelle der stellaren Nukleosynthese ein. Kürzlich gelang es der internationalen ISOLTRAP‐Kollaboration mit Mitgliedern der Universitäten Greifswald und Mainz sowie des Max‐Planck‐Instituts für Kernphysik in Heidelberg und des Helmholtzzentrums für Schwerionenforschung in Darmstadt (GSI), das Isotop 229Rn mit einer “punktgenauen” massenspektrometrischen Messung zu entdecken.
Im Alleingang mit der Theorie
Authors: Loos Andreas 
Published: June 2009

AbstractSein Vater will nur auf Französisch mit seinen Kindern sprechen, damit sie die Sprache lernen. “Da ich mich aber auf Französisch nicht ausdrücken konnte, war es besser, stumm zu bleiben”, erinnert sich der Gesuchte. “So wurde ich zu einem sehr frühen Zeitpunkt sehr schweigsam.” Tatsächlich entwickelt er sich zu einem schweigsamen, aber sehr erfolgreichen Physiker.
Gestärkte Saucen
Authors: Vilgis Thomas 
Published: June 2009

AbstractDie klassische Art, Saucen mit Kartoffel‐, Mais‐ oder Weizenstärke zu binden, ist nach wie vor sehr effektiv. Schon die Zugabe einer kleinen Menge davon ergibt nach dem Erwärmen auf etwa 70 °C eine wundersam eingedickte Sauce – dank der molekularen Struktur von Stärkemolekülen. Vor allem das hochverzweigte Amylopektin erweist sich dabei als Saucenbinder besonders relevant.
Proteomics analysis of two mice hepatocarcinoma ascites syngeneic cell lines with high and low lymph node metastasis rates provide potential protein markers for tumor malignancy attributes to lymphatic metastasis
Authors: Sun Ming‐Zhong , Liu Shuqing , Tang Jianwu , Wang Zhiqiang , Gong Xiaolin , Sun Chengrong , Greenaway Frederic 
Published: June 2009

AbstractLymph node metastasis (LNM) is recognized as an important factor involved in the tumor malignancy progression. Our previous study has indicated that the hepatocarcinoma cell line with 75% of LNM (Hca‐F)‐cell‐induced neoplasia and the hepatocarcinoma cell line with 25% of LNM‐induced neoplasia are accompanied with high (75%) and low (25%) incidences of LNM. In the current study, 62 and 54 protein spots were observed up‐regulated and down‐regulated in Hca‐F cell relative to the hepatocarcinoma cell line with 25% of LNM by 2‐D DIGE. Totally, 113 unique proteins were identified by HPLC‐nano ESI‐MS/MS analysis. The expression levels of Annexin A7, Ulch3, and ER protein 29 were validated by Western blotting analyses. The abnormally regulated proteins were categorized and annotated by protein analysis through evolutionary relationships analysis with the aid of the database for annotation, visualization and integrated discovery tool. Seventeen gene candidates concordantly expressed both at mRNA and protein levels. By making a challenge, we detected expression levels of Annexin A7 in primary gastric cancer (GC) and primary GC cancer tissues with LNMs by immunohistochemisty. Higher ratio of positive and strong expressions Annexin A7 in GC might correlate with the tumor progression. The repression of Annexin A7 inhibits the mobility and invasion abilities of Hca‐F cell, increases the apoptosis rate of Hca‐F cell. Current study narrows and provides certain specific protein candidates potentially playing important roles in LNM‐associated cancers.
Systems approach to explore components and interactions in the presynapse
Authors: Abul‐Husn Noura S. , Bushlin Ittai , Morón José A. , Jenkins Sherry L. , Dolios Georgia , Wang Rong , Iyengar Ravi , Ma'ayan Avi , Devi Lakshmi A. 
Published: June 2009

AbstractThe application of proteomic techniques to neuroscientific research provides an opportunity for a greater understanding of nervous system structure and function. As increasing amounts of neuroproteomic data become available, it is necessary to formulate methods to integrate these data in a meaningful way to obtain a more comprehensive picture of neuronal subcompartments. Furthermore, computational methods can be used to make biologically relevant predictions from large proteomic data sets. Here, we applied an integrated proteomics and systems biology approach to characterize the presynaptic (PRE) nerve terminal. For this, we carried out proteomic analyses of presynaptically enriched fractions, and generated a PRE literature‐based protein–protein interaction network. We combined these with other proteomic analyses to generate a core list of 117 PRE proteins, and used graph theory‐inspired algorithms to predict 92 additional components and a PRE complex containing 17 proteins. Some of these predictions were validated experimentally, indicating that the computational analyses can identify novel proteins and complexes in a subcellular compartment. We conclude that the combination of techniques (proteomics, data integration, and computational analyses) used in this study are useful in obtaining a comprehensive understanding of functional components, especially low‐abundance entities and/or interactions in the PRE nerve terminal.
Effect of phosphorylated hsp27 on proliferation of human endothelial and smooth muscle cells
Authors: Trott Deborah , McManus Ciara A. , Martin Jody L. , Brennan Bryony , Dunn Michael J. , Rose Marlene L. 
Published: June 2009

AbstractRecent studies have suggested a protective role of hsp27 against atherosclerosis and transplant graft vasculopathy. Here we have investigated the effects of over‐expression of wild‐type hsp27 and its phosphorylation mimics on proliferation of human endothelial cells (ECs) and smooth muscle cells (SMCs). ECs and SMCs cultured from human blood vessels or cells lines (human microvascular endothelial cell line and human telomerase reverse transcriptase subunit SMC) were infected with adenovirus containing DNA from wild‐type hsp27, hyper‐phosphorylated hsp27 mimic (3D hsp27), hypo‐phosphorylated hsp27 mimic (3A hsp27) or anti‐sense hsp27, and proliferation measured over the next 5 days. Protein extracts from infected cells were subjected to proteomic analysis using 2‐D DIGE. Over‐expression of 3D hsp27 and anti‐sense hsp27 but not 3A hsp27 mimic caused significant inhibition of proliferation of ECs and SMCs. Proteomic analysis focussed on proteins that were significantly down‐regulated by the 3D hsp27 mutant. The cell cycling proteins stathmin, cofilin and ubiquitination enzymes fullfilled these criteria. 1‐D Western blots of infected human microvascular endothelial cell line and human telomerase reverse transcriptase subunit SMC confirmed down‐regulation of stathmin, cofilin and ubiquitination enzymes by 3D hsp27. The phosphorylation status of hsp27 is an important regulator of proliferation of human vascular ECs and SMCs; possibly contributing to cardiovascular protection.
Controlled Amine Functionalization and Hydrophilicity of a Poly(lactic acid) Fabric
Authors: Dai Xiujuan J. , Plessis Johan du , Kyratzis I. Louis , Maurdev George , Huson Mickey G. , Coombs Chris 
Published: June 2009

AbstractThe surface of PLA fabric has been successfully modified by pulsed plasma polymerization of heptylamine (PPHA) giving increased hydrophilicity and achieving a sufficient level of primary amine functionality (3.5%) for practical application in biotechnology. This is the first report that the density of primary amine (–NH2) in PPHA, quantified by chemical derivatization, can be controlled by selection of pulsed plasma conditions. The duty cycle and the average RF power were the key parameters for achieving both a higher density of primary amine and increased hydrophilicity.magnified image
Structure, Chemical and Physical Behavior of Aluminum Hydride
Authors: Kempa Paul Bernd , Thome Volker , Herrmann Michael 
Published: June 2009

AbstractThe literature concerning the structure and stabilization of Aluminum hydride (AlH3) was reviewed, and a detailed characterization of a stabilized sample was performed.The main disadvantage for the application of AlH3as an ingredient in propellants is its sensitivity towards oxidation and hydration. Stabilization by additives or a coating is required to ensure the safe handling of AlH3. Different stabilization concepts have already been described in the literature and are summarized here.The investigation of the AlH3sample shows an effective stabilization mechanism, which enables safe handling. It is concluded that this has been achieved by a protective coating with aluminum‐hydroxide clusters.
Folding in solution of the C‐catalytic protein fragment of angiotensin‐converting enzyme
Authors: Vamvakas Sotirios‐Spyridon M. , Leondiadis Leondios , Pairas George , Manessi‐Zoupa Evy , Spyroulias Georgios A. , Cordopatis Paul 
Published: June 2009

AbstractAngiotensin‐converting enzyme (ACE) is a key molecule of the renin–angiotensin–aldosterone system which is responsible for the control of blood pressure. For over 30 years it has become the target for fighting off hypertension. Many inhibitors of the enzyme have been synthesized and used widely in medicine despite the lack of ACE structure. The last 5 years the crystal structure of ACE separate domains has been revealed, but in order to understand how the enzyme works it is necessary to study its structure in solution. We present here the cloning, overexpression inEscherichia coli, purification and structural study of the Ala959to Ser1066region (ACE_C) that corresponds to the C‐catalytic domain of human somatic angiotensin‐I‐converting enzyme. ACE_C was purified under denatured conditions and the yield was 6 mg/l of culture. Circular dichroism (CD) spectroscopy indicated that 1,1,1‐trifluoroethanol (TFE) is necessary for the correct folding of the protein fragment. The described procedure can be used for the production of an isotopically labelled ACE959–1066protein fragment in order to study its structure in solution by NMR spectroscopy. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
A comparative life cycle assessment of single‐use fibre drums versus reusable steel drums
Authors: Raugei Marco , Fullana‐i‐Palmer Pere , Puig Rita , Torres Alejo 
Published: June 2009

AbstractThis paper deals with a comparative analysis of two different packaging and transport scenarios, which exemplifies the implications of choosing between single‐use and reusable packaging. In particular, transport of a batch of chemicals by means of disposable fibre drums versus reusable steel drums is investigated from a life cycle perspective, and the associated environmental impact in terms of global warming potential, acidification potential, gross energy requirement and solid waste generation is assessed. Results prove beyond reasonable doubt that even in the case of durable packaging containers requiring the use of comparatively energy‐intensive materials for their production, the reuse scenario is characterized by lower environmental impact indicators across the board, and as such is the most advisable and environmentally sound option. Copyright © 2009 John Wiley & Sons, Ltd.
Exponential H∞ filter design for stochastic time‐varying delay systems with Markovian jumping parameters
Authors: Ma Li , Da Feipeng 
Published: June 2009

AbstractIn this paper, the exponential H∞ filter design problem is investigated for a general class of stochastic time‐varying delay system with Markovian jumping parameters. The stochastic uncertainties appear in both the dynamic and the measurement equations and the state delay is assumed to be time‐varying. Attention is focused on the design of mean‐square exponentially stable and Markovian jump filter such that the filtering error systems are mean‐square exponentially stable and the estimation error satisfies a given H∞ performance. By introducing some slack matrix variables, delay‐dependent sufficient conditions for the solvability of the above problem are presented in terms of linear matrix inequalities (LMIs). In addition, the decay rate can be a given positive value without any other constraints. When the proposed LMIs are feasible, an explicit expression of the desired H∞ filter can be given. A numerical example is provided to illustrate the effectiveness of the proposed design approach. Copyright © 2009 John Wiley & Sons, Ltd.
Uniform random sampling of planar graphs in linear time
Authors: Fusy Éric 
Published: June 2009

AbstractThis article introduces new algorithms for the uniform random generation of labelled planar graphs. Its principles rely on Boltzmann samplers, as recently developed by Duchon, Flajolet, Louchard, and Schaeffer. It combines the Boltzmann framework, a suitable use of rejection, a new combinatorial bijection found by Fusy, Poulalhon, and Schaeffer, as well as a precise analytic description of the generating functions counting planar graphs, which was recently obtained by Giménez and Noy. This gives rise to an extremely efficient algorithm for the random generation of planar graphs. There is a preprocessing step of some fixed small cost; and the expected time complexity of generation is quadratic for exact‐size uniform sampling and linear for uniform approximate‐size sampling. This greatly improves on the best previously known time complexity for exact‐size uniform sampling of planar graphs with n vertices, which was a little over O(n7). © 2009 Wiley Periodicals, Inc. Random Struct. Alg., 2009
Success factors for globally distributed projects
Authors: Zopf Siegfried 
Published: June 2009

AbstractThe report presents the essence of experience from hundreds of development projects distributed over locations in eight countries with different languages and culture. The report distinguishes between distributed projects within the own organisation and cooperation with other companies and also the extent of outsourcing. The role of a beach‐head in the head quarters is described. One success factor is professional project management based on a well‐defined development process. The report highlights the software engineering practices that have special importance in distributed projects. Practical tips will be given for how to deal with soft facts as esteem and team building in global projects. It is explained how to avoid falling into traps in communication between different cultures in foreign languages. Copyright © 2009 John Wiley & Sons, Ltd.
Product line requirements engineering in the context of process aspects in organizations with various domains
Authors: Poth Alexander 
Published: June 2009

AbstractSoftware product lines are used today in many domains. The obvious conclusion is that product lines are a useful concept. This article describes practical experiences gained with the adaptation of product line processes and methods in projects in the automotive, finance, and telecommunication domain. It discusses generic topics and also gives a brief introduction into selected specific topics. The focus is on requirements management and engineering for product lines. The observations are consolidated in a reference model for consulting services in the product line context. Copyright © 2009 John Wiley & Sons, Ltd.
Lightweight SPI assessments: what is the real cost?
Authors: McCaffery Fergal , Coleman Gerry 
Published: June 2009

AbstractIn this article, we describe the implementation of an assessment method that was developed to assess software processes within small to medium‐sized Irish software organisations that have little or no experience of software process improvement (SPI) programmes. We discuss the actual overheads associated with performing software process assessments based upon our experiences of performing assessments in three small to medium‐sized (SMEs) software development companies. Copyright © 2009 John Wiley & Sons, Ltd.
Rapid algal toxicity assay using variable chlorophyll fluorescence for Chlorella kessleri (chlorophyta)
Authors: Kvíderová Jana 
Published: June 2009

AbstractThree methods of algal assays—the standard assay, microassay, and the proposed fluorescence assay—are compared from the point of view of reliability of EC50 detection, the minimum required time for the detection, sensitivity of individual measurement, i.e. at which cell density the particular assay can be used for EC50 estimation, and the time stability of the EC50 values. The assays were performed with green alga Chlorella kessleri strain LARG/1 growing in potassium dichromate solution in Z‐medium ranging from 0.01 to 100 mg Cr L−1. The inoculation cell density was set according to the standards to 104 cells mL−1 and according to spectrophotometer/plate reader detection limit. The average EC50 ranged from 0.096 to 0.649 mg Cr L−1 and there were no significant differences in EC50 between the assay type and the inoculation methods with the exception of the significant difference between ECc5072 (EC50 established from biomass measured as chlorophyll a concentration after 72 h of cultivation) in the standard assay and ECr50 (EC50 derived from growth rate) in the microassay in the standard inoculation experiment due to low variability of their values. The ECf50 (EC50 derived from variable fluorescence measurement) values correspond to EC50 values derived from the growth rates. Fluorescence measurement revealed the toxic effect of the chromium after 24 h of exposure at cell density of 5 × 104 cells mL−1, less by half than other used assay methods. The positive correlation of ECf50 and time was found in the standard inoculation experiment but opposite effect was observed at the spectrophotometric one. © 2009 Wiley Periodicals, Inc. Environ Toxicol 25: 554–563, 2010.
Real‐time visualization of oxidative stress in a floating macrophyte Lemna minor L. exposed to cadmium, copper, menadione, and AAPH
Authors: Razinger Jaka , Drinovec Luka , Zrimec Alexis 
Published: June 2009

AbstractAn ultra‐sensitive digital imaging system was employed to visualize oxidative stress in intact L. minor plants exposed to Cd, Cu, menadione, AAPH, and ascorbate in real time. The increase of ROS production was assessed by measuring the rate of fluorescence intensity increases of the test medium supplemented with a fluorescing probe (dichlorofluorescein diacetate). The addition of 100 μM CdCl2 or 100 μM CuSO4 to the growth medium resulted in a significant increase of medium fluorescence. Additionally, CuSO4 caused a significantly higher fluorescence intensity than CdCl2 did. A strong positive correlation (R2 = 0.99) between menadione concentration and fluorescence intensity was observed. The positive correlation between AAPH concentration and fluorescence intensity was not as strong as in the case of menadione (R2 = 0.81). Menadione induced a stronger oxidative stress than similar concentration of AAPH. The addition of 100 μM ascorbate to L. minor treated with 50 μM menadione significantly reduced the fluorescence intensity increase. A linear trend of the fluorescence increase was observed in all treatments, indicating that chemical‐induced oxidative stress is a gradual process and that the applied concentrations of the chemicals caused a constant increased production of ROS with different intensities, depending on the treatment. This is the combined result of a gradual diminishing of antioxidant reserves and accumulating oxidative damage. The observed rates of ROS production were slower than those in the studies using cell cultures. © 2009 Wiley Periodicals, Inc. Environ Toxicol 25: 573–580, 2010.
Simulation‐based real‐time routing protocol with load distribution in wireless sensor networks
Authors: Ali A. , Latiff L. A. , Fisal N. 
Published: June 2009

AbstractIn wireless sensor networks (WSNs), sensors gather information about the physical world and the base station makes decision and then performs appropriate actions upon the environment. This technology enables a user to effectively sense and monitor from a distance in real‐time. WSNs demand real‐time forwarding which means messages in the network are delivered according to their end‐to‐end deadlines (packet lifetime). This paper proposes a novel real‐time routing protocol with load distribution (RTLD) that ensures high packet throughput with minimized packet overhead and prolongs the lifetime of WSN. The routing depends on optimal forwarding (OF) decision that takes into account of the link quality (LQ), packet delay time and the remaining power of next hop sensor nodes. The proposed mechanism has been successfully studied through simulation work. Copyright © 2009 John Wiley & Sons, Ltd.
Cooperative cache consistency maintenance for pervasive internet access
Authors: Huang Yu , Cao Jiannong , Jin Beihong , Tao Xianping , Lu Jian 
Published: June 2009

AbstractCooperative caching is an important technique to support pervasive Internet access. In order to ensure valid data access, the cache consistency must be maintained properly. However, this problem has not been sufficiently studied in mobile computing environments, especially those with ad hoc networks. There are two essential issues in cache consistency maintenance: consistency control initiation and data update propagation. Consistency control initiation not only decides the cache consistency provided to the users, but also impacts the consistency maintenance cost. This issue becomes more challenging in asynchronous and fully distributed ad hoc networks. To this end, we propose the predictive consistency control initiation (PCCI) algorithm, which adaptively initiates consistency control based on its online predictions of forthcoming data updates and cache queries. In order to efficiently propagate data updates through multi‐hop wireless connections, the hierarchical data update propagation (HDUP) algorithm is proposed. Theoretical analysis shows that cooperation among the caching nodes facilitates data update propagation. Extensive simulations are conducted to evaluate performance of both PCCI and HDUP. Evaluation results show that PCCI cost‐effectively initiates consistency control even when faced with dynamic changes in data update rate, cache query rate, node speed, and number of caching nodes. The evaluation results also show that HDUP saves cost for data update propagation by up to 66%. Copyright © 2009 John Wiley & Sons, Ltd.