bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel 3,6‐Disubstituted 7H‐1,2,4‐Triazolo[3,4‐b][1,3,4]thiadiazines: Synthesis, Characterization, and Evaluation of Analgesic / Anti‐inflammatory, Antioxidant Activities
Authors: Tozkoparan Birsen , Aytaç Sevim Peri , Aktay Göknur 
Published: May 2009

AbstractIn this study, the synthesis of a new series of 3,6‐disubstituted‐7H‐1,2,4‐triazolo[3,4‐b][1,3,4]thiadiazine 1a–4c compounds derived from 4‐amino‐3‐substituted‐1,2,4‐triazole‐5‐thiones 1–4 is described. All of the synthesized compounds were screened for their possible analgesic / anti‐inflammatory, antioxidant activities and gastric toxicity. The compound 2c was found to have both significant analgesic and consistent anti‐inflammatory activity without inducing any gastric lesions along with minimal lipid peroxidation. A deep insight into the structures of the active compounds revealed that the compounds carrying an electron withdrawing group (a chloride or fluoride) on the phenyl ring at 6‐position of the condensed heterocyclic derivatives exhibited noticeable higher activity.
Synthesis and Biological Evaluation of Some Novel Polysubstituted Pyrimidine Derivatives as Potential Antimicrobial and Anticancer Agents
Authors: Rostom Sherif A. F. , Ashour Hayam M. A. , Abd El Razik Heba A. 
Published: May 2009

AbstractSynthesis and evaluation of the antimicrobial and cytotoxic activity of two series of polysubstituted pyrimidines comprising the thioether functionality and other pharmacophores, reported to contribute to various chemotherapeutic activities are described. All newly synthesized compounds were subjected to in‐vitro antibacterial and antifungal screening. Out of the compounds tested, 18 derivatives displayed an obvious inhibitory effect on the growth of the tested Gram‐positive and Gram‐negative bacterial strains, with special effectiveness against the Gram‐positive strains. Compounds 1, 2, 6, 7, 9, 10, 11, 21, and 24 revealed remarkable broad antibacterial spectrum profiles. Among those, compounds 1, 2, 6, 7, 9, and 24 exhibited an appreciable antifungal activity against C. albicans. Compound 2 proved to be the most active antimicrobial member identified here as it showed twice the activity of ampicillin against B. subtilis and the same activity of ampicillin against M. Luteus and P. aeruginosa together with a moderate antifungal activity. Further, eleven analogs were evaluated for their in‐vitro cytotoxic potential utilizing the standard MTT assay against a panel of three human cell lines: breast adenocarcinoma MCF7, hepatocellular carcinoma HePG2, and colon carcinoma HT29. The obtained data revealed that six of the tested compounds 1, 3, 7, 12, 13, and 15 showed a variable degree of cytotoxic activity against the tested cell lines at both the LC50 and LC90 levels. Compound 7 proved to be the most active cytotoxic member in this study with special effectiveness against the colon carcinoma HT29 and breast cancer MCF7 human cell lines for LC50 and LC90. Thus, compounds 1 and 7 could be considered as possible dual antimicrobial‐anticancer agents.
Execution models for reconfigurable embedded real‐time systems
Authors: Khalgui Mohamed , Hanisch Hans‐Michael 
Published: May 2009

AbstractThis paper deals with the verification and assignment into the execution environment of Reconfigurable Control Applications following the Component‐based International Industrial Standard IEC61499. According to this Standard, a Function Block (FB) is an event‐triggered component and an application is an FB network that has to meet temporal properties according to user requirements. If a reconfiguration scenario is applied at run‐time, then the FB network implementing the application is totally changed or modified. To cover all possible cases, we classify such scenarios into three classes and we define an agent‐based architecture designed with nested state machines to automatically handle all possible reconfigurations. To verify and assign Function Blocks corresponding to each reconfiguration scenario into the execution environment, we define an approach based on the exploration of reachability graphs to verify temporal properties. This approach constructs feasible Operating System tasks encoding the FB network that corresponds to each scenario. Therefore, the application is considered as sets of Operating System (OS) tasks where each set is to load in memory when the corresponding reconfiguration scenario is applied by the agent. We developed the toolX‐Assignsupporting these contributions that we apply on the FESTO production system available in our research laboratory. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Improved exponential estimates for neutral systems
Authors: Shu Zhan , Lam James , Xu Shengyuan 
Published: May 2009

AbstractImproved exponential estimates and a new sufficient condition for the exponential stability of neutral type time‐delay systems are established in terms of linear matrix inequalities (LMIs). A new Lyapunov‐Krasovskii functional candidate with appropriately constructed exponential terms is introduced to prove the exponential stability and to reduce the conservatism. For the uncertain case, a corresponding condition for the robust exponential stability is also given. It is shown by numerical examples that the proposed conditions are less conservative than existing results. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
A novel approach for root distribution analysis of linear time‐invariant systems using Routh and Fuller tables
Authors: Sivanandam S. N. , Deepa S. N. 
Published: May 2009

AbstractThe root distribution of a given characteristic equation of a linear time‐invariant system can be analyzed with the help of a Routh table using the elements of the first column in the table. In the case of unstable systems, sometimes, a zero element may appear in the third row of the first column of the Routh array. This prematurity can be suitably handled as indicated by various authors. In this paper, the given characteristic polynomial having roots in the right hand plane is multiplied by a suitable polynomial, and Routh and Fuller tables are applied for the resultant polynomial to infer the complete root distribution. Further, the column polynomials from each table are adopted to know more about root distribution, which forms the core of the proposed work. The Routh table helps in counting and locating roots in the s‐plane, and the Fuller table helps in depicting whether the roots are distinct or complex in nature. In this regard, it is shown in this paper that the simultaneous integration of Routh and Fuller tables yields a good amount of information regarding the root distribution in the s‐plane. The newly presented procedure is illustrated with examples. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Tracking control of a piezo‐actuated stage based on a frictional model
Authors: Huang Yi‐Cheng , Lin Mou‐Sheng 
Published: May 2009

AbstractThe tracking control accuracy of a piezoelectric actuator (PEA) is limited due to the actuator's inherent hysteretic nonlinearity. Direct drive of PEA on a positioning stage with friction force will cause control problems. An approximated dynamic model of PEA with consideration of friction force is novel synthesized for control. This model is based on a second‐order transfer function with two parameterization terms. The first time delay term consists of the hysteresis of piezo effect combined with frictional force lag with varying velocity. The second term is comprised of both presliding and sliding regimes. The H‐infinite tracking controller is designed to compensate for the structural uncertainty associated with time delay and the unstructured frictional force in the PEA stage. Iterative Learning Control is implemented to reduce the unmodeled repetitive error by a factor of 20. Numerical simulations and experimental tests consolidate the root mean square (RMS), positioning error close to the hardware reproducibility and accuracy level. Experimental results show the controlled stage can be potentially used for precise positioning. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
ESA in high‐order linear systems via output feedback
Authors: Yu Hai‐Hua , Duan Guang‐Ren 
Published: May 2009

AbstractThis paper considers eigenstructure assignment in high‐order linear systems via output feedback. Parametric expressions for the left and right closed‐loop eigenvectors associated with the finite closed‐loop eigenvalues and two simple and complete parametric solutions for the feedback gain matrices are obtained on the basis of the parametric solutions of the generalized high‐order Sylvester matrix equations. This approach does not impose any restrictions on the closed‐loop eigenvalues. An illustrative example shows the effect of the proposed approach. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Finite‐time tracking control of a nonholonomic mobile robot
Authors: Wang Zhao , Li Shihua , Fei Shumin 
Published: May 2009

AbstractIn this paper, the finite‐time tracking problem is investigated for a nonholonomic wheeled mobile robot in a fifth‐order dynamic model. We consider the whole tracking error system as a cascaded system. Two continuous global finite‐time stabilizing controllers are designed for a second‐order subsystem and a third‐order subsystem respectively. Then finite‐time stability results for cascaded systems are employed to prove that the closed‐loop system satisfies the finite‐time stability. Thus the closed‐loop system can track the reference trajectory in finite‐time when the desired velocities satisfy some conditions. In particular, we discuss the control gains selection for the third‐order finite‐time controller and give sufficient conditions by using Lyapunov and backstepping techniques. Simulation results demonstrate the effectiveness of our method. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Impulsive‐mode controllablizability revisited for descriptor linear systems
Authors: Wu Ai‐Guo , Duan Guang‐Ren , Yu Hai‐Hua 
Published: May 2009

AbstractNew criteria for impulsive‐mode controllablizability of descriptor linear systems are proposed by adopting the null space approach. The range of the possible dynamical orders of the closed‐loop system with impulsive‐mode controllability is characterized in terms of the original system matrices. Moreover, the parametric expressions of the impulsive‐mode controllablizing controllers are also established. Since only the orthogonal transformations are involved, the design approach is numerically stable. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Amino acids as regulators of gene expression in mammals: Molecular mechanisms
Authors: Bruhat Alain , Chérasse Yoan , Chaveroux Cédric , Maurin Anne‐Catherine , Jousse Céline , Fafournoux Pierre 
Published: May 2009

AbstractIn mammals, the impact of nutrients on gene expression has become an important area of research. Because amino acids have multiple and important functions, their homeostasis has to be finely maintained. However, amino acidemia can be affected in some nutritional conditions and by various forms of stress. Consequently, mammals have to adjust physiological functions involved in the adaptation to amino acid availability. Part of this regulation involves the modulation of numerous gene expression. It has been shown that amino acids by themselves can modify the expression of target genes. This review focuses on the recent advances in the understanding of the mechanisms involved in the control of mammalian gene expression in response to amino acid limitation. © 2009 International Union of Biochemistry and Molecular Biology, Inc.
The endoplasmic reticulum stress signaling pathways in plants
Authors: Urade Reiko 
Published: May 2009

AbstractThe unfolded protein response (UPR) is an evolutionarily conserved mechanism by which all eukaryotic cells preserve the homeostasis of the endoplasmic reticulum (ER) in the face of accumulation of unfolded proteins in the ER. Plants possess at least two signaling pathways specific for UPR. ER membrane‐bound ER stress sensor/transducers, AtbZIP60 and AtbZIP28, are basic leucine zipper transcription factors that are activated by regulated intramembrane proteolysis systems and regulate transcription of the UPR genes. These signaling pathways play important roles not only in the UPR but also in other biological processes such as the response to pathogens and heat stress. © 2009 International Union of Biochemistry and Molecular Biology, Inc.
Disulfide Bond Substitution by Directed Evolution in an Engineered Binding Protein
Authors: Drevelle Antoine , Urvoas Agathe , Hamida‐Rebaï Mériam Ben , Van Vooren Gérard , Nicaise Magali , Valerio‐Lepiniec Marie , Desmadril Michel , Robert Charles H. , Minard Philippe 
Published: May 2009

AbstractBreaking ties: The antitumour protein, neocarzinostatin (NCS), is one of the few drug‐carrying proteins used in human therapeutics. However, the presence of disulfide bonds limits this protein's potential development for many applications. This study describes a generic directed‐evolution approach starting from NCS‐3.24 (shown in the figure complexed with two testosterone molecules) to engineer stable disulfide‐free NCS variants suitable for a variety of purposes, including intracellular applications.magnified imageThe chromoprotein neocarzinostatin (NCS) has been intensively studied for its antitumour properties. It has recently been redesigned as a potential drug‐carrying scaffold. A potential limit of this protein scaffold, especially for intracellular applications, is the presence of disulfide bonds. The objective of this work was to create a disulfide‐free NCS‐derived scaffold. A generic targeted approach was developed by using directed evolution methods. As a starting point we used a previously engineered NCS variant in which a hapten binding site had been created. A library was then generated in which cysteine Cys88 and Cys93 and neighbouring residues were randomly substituted. Variants that preserved the hapten binding function were selected by phage display and further screened by colony filtration methods. Several sequences with common features emerged from this process. The corresponding proteins were expressed, purified and their biophysical properties characterised. How these selected sequences rescued folding ability and stability of the disulfide‐free protein was carefully examined by using calorimetry and the results were interpreted with molecular simulation techniques.
Phenolic Oxime Oligomers Inhibit Alzheimer's Amyloid Fibril Formation and Disaggregate Fibrils In Vitro
Authors: Dolphin Gunnar T. , Renaudet Olivier , Ouberai Myriam , Dumy Pascal , Garcia Julian , Reymond Jean‐Louis 
Published: May 2009

AbstractSee you later amyloid β: A screen of a small library of oxime oligomers with an HTS fluorescence assay for amyloid fibril inhibition and subsequent investigation by atomic force microscopy revealed two new micromolar inhibitors of amyloid fibril formation. These new inhibitors have IC50 values in the 10 μM range.magnified image
Polymer‐Säure‐Komposite auf Basis strahlungsinduzierter Pfropfpolymerisation für Hochtemperatur‐PEM‐Brennstoffzellen
Authors: Schmidt‐Naake G. 
Published: May 2009

AbstractKomposite aus basischen Polymeren und Säuren sind geeignete Protonenleiter für Polymerelektrolytmembran‐Brennstoffzellen (PEM‐FC), die bei 120 °C und höheren Temperaturen ohne oder mit nur geringer Befeuchtung der Betriebsgase arbeiten. Durch strahlungsinduzierte Pfropfpolymerisation auf handelsüblichen ETFE‐Filmen (Poly(tetrafluorethylen‐alt‐ethylen) stellt man mit den Monomeren 1‐Vinylimidazol, 4‐Vinylpyridin, N‐Vinylformamid und Glycidylmethacrylat basische Pfropfpolymere her und dotiert diese mit Phosphorsäure. In vergleichenden Struktur‐Eigenschafts‐Untersuchungen werden diese sehr unterschiedlichen Polymer‐Säure‐Komposite hinsichtlich erreichbarer Pfropfgrade, Dotierlevel, basischer Funktionsdichten, thermischer Stabilitäten, spezifischer Protonenleitfähigkeiten und des Brennstoffzellentests bewertet.
Entwicklung eines mikrostrukturierten Methanolreformers gekoppelt mit einer Hochtemperatur‐PEM Brennstoffzelle
Authors: Kolb Dr‐Ing. G. , Schelhaas K.‐P. , Wichert M. , Burfeind J. , Heßke C. , Bandlamudi G. 
Published: May 2009

AbstractZiel der vorliegenden Arbeit war es, einen portablen Stromerzeuger mit einer elektrischen Nettoleistung von 100 W zu realisieren. Dazu wurde am Institut für Mikrotechnik Mainz (IMM) ein integrierter mikrostrukturierter Methanolreformer auf der Basis des oxidativen Wasserdampfreformierens entwickelt. Der Reformer wurde nach Einzeltests schließlich mit einer vom Zentrum für Brennstoffzellentechnik (ZBT) entwickelten Hochtemperatur‐PEM‐Brennstoffzelle gekoppelt.
Modellgestützte verfahrenstechnische Berechnung eines Metallhydridspeichers auf Natriumalanatbasis im Technikumsmaßstab
Authors: Na Ranong C. , Höhne M. , Franzen J. , Hapke J. , Fieg G. , Dornheim M. 
Published: May 2009

AbstractIm Rahmen des EU‐Projekts STORHY ist der Prototyp eines Metallhydridspeichers auf Natriumalanatbasis für automobile Anwendungen entwickelt worden. Besonderes Merkmal ist die Größe im Vergleich zu bisher vorhandenen Laborreaktoren. Mit Hilfe einer modell‐gestützten Simulation wird sein Beladungsverhalten für verschiedene Betriebsbedingungen berechnet. Anhand der Ergebnisse werden die Wirksamkeit der Kühlung und ihr Optimierungspotenzial diskutiert.
Erdgas und Wasserstoff aus Faulgas – neue Nutzungsmöglichkeiten durch weitergehende Aufbereitung
Authors: Rossol D. , Teichgräber B. , Schröder M. 
Published: May 2009

AbstractWasserstoff gilt als Energieträger der Zukunft, insbesondere im Verkehrssektor. Bis zur flächendeckenden Einführung von Wasserstoff als Kraftstoff ist es allerdings noch ein weiter Weg. Als erste Bausteine auf diesem Weg zur Wasserstoff‐Infrastruktur bieten Kläranlagen für die Produktion und Bereitstellung von Wasserstoff viel versprechende Rahmenbedingungen. Diese Möglichkeiten wurden erstmalig in einem Pilotprojekt in einer großtechnischen Anlage zur Herstellung von hochreinem Wasserstoff aus Klärschlamm und anderer Biomasse umgesetzt. Als Zwischenprodukt bei der Wasserstofferzeugung entsteht im Aufbereitungsprozess Bioerdgas, das zur Betankung von Erdgasfahrzeugen genutzt wird. Die Erfahrungen aus der Planungs‐, der Genehmigungs‐, der Bau‐ und der Inbetriebnahmephase zeigen die grundsätzliche Verfügbarkeit entsprechender technologischer Komponenten, die Genehmigungsfähigkeit der Anlage und die Realisierbarkeit einer entsprechenden Verfahrenstechnik.
Elektrokatalyse in Brennstoffzellen und Elektrolyseuren: Kohlenstoff‐Nanoröhren‐basierte Katalysatoren und neuartige Untersuchungsmethoden
Authors: Bron M. , Xia W. , Chen X. , Jin C. , Kundu S. , Nagaiah T. , Chetty R. , Schilling T. , Li N. , Schuhmann W. , Muhler M. 
Published: May 2009

AbstractAuf dem Weg zu einer Markteinführung von PEM‐Brennstoffzellen gibt es trotz intensiver Forschung der letzten Jahrzehnte noch zahlreiche Herausforderungen zu überwinden. So besteht Bedarf an verbesserten, stabilen Elektrokatalysatoren, optimierten Elektrodenstrukturen sowie an geeigneten Methoden zur Aufklärung der Prozesse in arbeitenden Gasdiffusionselektroden. In diesem Beitrag werden Möglichkeiten diskutiert, diesen Herausforderungen zu begegnen. Vorgestellt werden Elektrokatalysatoren auf Basis von Kohlenstoff‐Nanoröhren (CNT)‐geträgerten Edelmetallen und Stickstoff‐modifizierten CNTs. Vorschläge zu einem gezielten Aufbau von Gasdiffusionselektroden mit Hilfe elektrochemischer Abscheidung der Aktivkomponente sowie ortsaufgelöste Methoden zur Charakterisierung von Gasdiffusionselektroden werden ebenfalls dargestellt.
Brennstoffzellen mit sauren Zeolithen als Ionenaustauschermedien und Vollmetallkatalysatoren
Authors: Erich E. 
Published: May 2009

AbstractNeben vielen technologischen Vorteilen weist die PEM‐Brennstoffzelle einige Nachteile auf, die eine erfolgreiche Markteinführung bremsen. Dazu gehören die Temperaturempfindlichkeit, die erforderliche Befeuchtung der Membran und auch der hohe Preis. Im Institut für Energie‐ und Umwelttechnik e. V. wurden Grundlagen für einen neuen Brennstoffzellentyp geschaffen, der aufgrund seines Funktionsprinzips und der verwendeten Werkstoffe das Potenzial hat, diese Hemmnisse zu überwinden. Die neue elektrochemische Zelle nutzt einen sauer eingestellten Zeolithen als Medium für den Ionenaustausch sowie Katalysatorsysteme auf der Basis elektrochemisch beschichteter, metallischer Substrate. Erste Ergebnisse werden mit diesem neuen System vorgestellt.
Wasserstofferzeugung und ‐distribution mit Mikroverfahrenstechnik
Authors: Pfeifer P. , Thormann J. , Görke O. , Bohn L. , Schubert K. 
Published: May 2009

AbstractIm vorliegenden Beitrag werden jüngste Ergebnisse zur Verbesserung der Effizienz kleiner Wasserstofferzeugungseinheiten (bis 5 kW H2) für mobile und stationäre Anwendungen auf Basis der Mikroverfahrenstechnik aus dem Institut für Mikroverfahrenstechnik (IMVT) beschrieben. Der Beitrag soll zeigen, dass die Kopplung exothermer und endothermer Teilschritte für eine hohe Effizienz der Wasserstofferzeugung bei Mikroapparaten notwendig ist und eine Koksbildung tolerierbar, gegebenenfalls sogar gezielt benutzbar sein kann. Darüber hinaus soll das Potenzial der Mikroverfahrenstechnik für die Distribution von flüssigem, tiefkaltem Wasserstoff für zukünftige Energiesysteme demonstriert werden.
Molecular analysis of pancreatic cyst fluid
Authors: Shen Jian , Brugge William R. , DiMaio Christopher J. , Pitman Martha B. 
Published: May 2009

AbstractBACKGROUND:The management of patients with pancreatic cysts is based on the preoperative distinction of nonmucinous and mucinous cysts in general and of benign and malignant cysts in particular. An accurate diagnosis is challenging, because endoscopic ultrasound (EUS) and cyst fluid analysis for carcinoembryonic antigen (CEA) and cytology have low sensitivity and specificity. Currently, molecular analysis is a commercially available test that promises an accurate diagnosis. The objective of the current study was to correlate a commercially provided molecular diagnosis (MDx) with a clinical consensus diagnosis (CCD) in the general categories of malignant, benign mucinous, and benign nonmucinous pancreatic cysts.METHODS:Pancreatic cysts that had aspirated fluid submitted for a commercially available molecular test (PathFinderTG) were reviewed. The CCD, defined by histology, malignant cytology, or 2 concordant tests (such as EUS, cytology, or CEA ≥192 ng/mL for mucinous cysts), was categorized as malignant, benign mucinous, or benign nonmucinous cyst in 35 patients. Their MDx, based on the PathFinderTG report, including analysis of k‐ras mutation, loss of heterozygosity, and quantity/quality of DNA, also was classified as malignant, benign mucinous, or benign nonmucinous cyst. These 2 diagnoses were compared and correlated.RESULTS:The concordance between CCD and MDx was 5 of 6 (83%), 13 of 15 (87%), and 13 of 14 (93%), respectively, for malignant, benign mucinous, and benign nonmucinous cysts, with an overall Cohen kappa statistic of 0.816. The sensitivity, specificity, and positive predictive value of the MDx were 83%, 100%, and 100%, respectively, for a malignant cyst and 86%, 93%, and 95%, respectively for a benign mucinous cyst.CONCLUSIONS:Molecular analysis of pancreatic cyst fluid adds diagnostic value to the preoperative diagnosis with high sensitivity, specificity, and positive predictive value for the diagnosis of malignant and benign mucinous pancreatic cysts. Cancer (Cancer Cytopathol) 2009. © 2009 American Cancer Society.