bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of temperature and pH on the kinetics of the Sharon nitritation process
Authors: Van Hulle Stijn WH , Volcke Eveline IP , Teruel Josefa López , Donckels Brecht , van Loosdrecht Mark CM , Vanrolleghem Peter A 
Published: May 2007

AbstractThe SHARON (Single reactor High activity Ammonia Removal Over Nitrite) process is an innovative process that improves the sustainability of wastewater treatment, especially when combined with an Anammox process. It aims at ammonium oxidation to nitrite only, while preventing further nitrate formation. In order to optimize this process by means of modelling and simulation, parameters of the biological processes have to be assessed. Batch tests with SHARON sludge clearly showed that ammonia rather than ammonium is the actual substrate and nitrous acid rather than nitrite is the actual inhibitor of the ammonium oxidation in the SHARON process. From these batch tests the ammonia affinity constant, the nitrous acid inhibition constant and the oxygen affinity constant were determined to be 0.75 mgNH3‐N L−1, 2.04 mgHNO2‐N L−1 and 0.94 mgO2 L−1. The influence of pH and temperature on the oxygen uptake rate of SHARON biomass was determined, indicating the existence of a pH interval between 6.5 and 8 and a temperature interval from 35 to 45 °C where the biomass activity is maximal. The kinetic parameters of the SHARON process were determined based on batch experiments. These parameters can now be implemented in a simulation model for further optimization of the SHARON process. Copyright © 2007 Society of Chemical Industry
Osteointegration of titanium and hydroxyapatite rough surfaces in healthy and compromised cortical and trabecular bone: in vivo comparative study on young, aged, and estrogen‐deficient sheep
Authors: Borsari Veronica , Fini Milena , Giavaresi Gianluca , Rimondini Lia , Consolo Ugo , Chiusoli Loris , Salito Armando , Volpert Andreas , Chiesa Roberto , Giardino Roberto 
Published: May 2007

AbstractThe osteointegration rate of titanium (Ti; TI01) and duplex Ti plus HA (HT01) coating systems with high surface roughness was investigated in healthy, aged, and oestrogen‐deficient sheep. After having evaluated the bone quality, TI01 and HT01 rods were implanted in the tibial diaphyses (two implants for each tibia) and epiphyses (1 implant for each tibia) of five young (YOUNG), five aged (AGED), and five aged and ovariectomized (OVX) sheep. The iliac crest trabecular bone volume (BV/TV) and number (Tb.N) in OVX sheep were respectively 33.5% and 28.5% lower than in YOUNG sheep (p < 0.005) and lower than in the AGED group (BV/TV, −17%; Tb.N, −13.5%; not significant); in the OVX group the trabecular separation was 77.9% higher than in YOUNG (p < 0.05) and 30.9% higher than in AGED animals. Lumbar vertebrae L5 bone mineral density was significantly lower in AGED (8.9%, p < 0.05) and OVX sheep (19.3%, p < 0.0005) when compared with YOUNG animals. Five samples of five sheep from each group were analyzed for each observation. At 3 months, in cortical bone both affinity index and pushout test results showed no significant differences between the two materials in each group of animals. In trabecular bone, the affinity index of HT01 was significantly higher than that of TI01 in each group of animals (YOUNG, 90.7%; AGED, 76.9%; OVX, 49.9%) with no significant differences between groups. In conclusion, the performance of TI01 and HT01 surfaces was high not only in YOUNG, but also in OVX animals and, therefore, they might be useful for aged and osteoporotic patients. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1250–1260, 2007
Characterization of sulphate transporters in isolated bovine articular chondrocytes
Authors: Meredith David , Gehl Katharina A. , Seymour John , Ellory J. Clive , Wilkins Robert J. 
Published: May 2007

AbstractUptake of SO by articular chondrocytes is an essential step in the pathway for sulphation of glycosaminoglycans (GAGs), with mutations in SO transport proteins resulting in abnormalities of skeletal growth. In the present study, the transporters mediating SO transport in bovine articular chondrocytes have been characterized. Expression of candidate transporters was determined using RT‐PCR, while SO transport was measured in radioisotope flux experiments. RT‐PCR experiments showed that bovine articular chondrocytes express three transporters known to transport SO: AE2 (SLC4a2), DTDST (SLC26a2), and SLC26a11. Other transporters—NaS‐1 (SLC13a1), SAT‐1 (SLC26a1), DRA (SLC26a3), SLC26a6 (PAT1), SLC26a7, SLC26a8 (Tat‐1), and SLC26a9—were, however, not detected. In functional experiments, SO uptake was temperature‐sensitive, inhibited by 60% by DIDS (50 µM) and exhibited saturation kinetics, with a Km value of 16 mM. Uptake was also inhibited at alkaline extracellular pH. In further experiments, a Ki value for DIDS inhibition of SO efflux of 5 µM was recorded. A DIDS‐sensitive component of SO efflux persisted in solutions lacking Cl− ions. These data are interpreted as evidence for the preferential operation of carrier‐mediated exchange of SO for Cl−, while an alternative SO–OH− exchange mode is also possible. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Definitizability of Certain Functions and the Existence of Eigenvectors of Unitary Operators in Pontrjagin Spaces
Authors: Sasvári Zoltán 
Published: May 2007

AbstractLetPkc(G) denote the set of continuous functions withknegative squares on a locally compact commutative groupG.Every functionfϵPkc(G) is definitizable in the sense thatmagnified imageis positive definite for certain complex measures ω onGwith finite support [9]. The proof of this fact was base on a result of M. A. Naimark about common nonpositive eigenvectors of commuting unitary operators in a Pontrjagin space. It is the aim of this note to prove without any use of the theory of Pontrjagin spaces the definitizability of functionsfϵPkc(G) which are of polynomial growth. In Section 3 we show, how the definitizability of functionsfϵPkc(G) can be used to prove the existence of common non‐positive eigenvectors of commuting unitary operators in a Pontrjagin space.
On the Almost Sure Convergence of Floating‐Point Mantissas and Benford's Law
Authors: Schatte Peter 
Published: May 2007

AbstractLet Y1, Y2,… be a sequence of random variables and let Mn be the floating‐point mantissa of Yn. Further let 11,x)(·) denote the indicator of the interval (1,x). If Yn/n→Z a.s., where Z ≠ 0 is a further random variable, then the sequence 1(1,x)(Mn) converges a.s. to log x in the sense of 𝒳 ∞‐means and logarithmic means, respectively. The speed of convergence in this relations is estimated. As a conclusion, a further argument for Benford's law is provided.
Critical behavior of some measure‐valued processes
Authors: Fleischmann Klaus 
Published: May 2007

AbstractThe so‐called weighted occupation time process Y associated with some critical measur‐evalued branching process is considered. Y has absolutely continuous states provided that the dimension of the phase space is small enough. The corresponding density functions form a random process η. In some cases there exists a critical dimension such that η. considered in the space‐time diagram, is a self‐similar random non‐negative field. This self‐similar field is infinitely divisible but not stable.
Symmetries on Riemannian Manifolds
Authors: Ledger A. J. , Vanhecke L. 
Published: May 2007

AbstractLocally symmetric KÄHLER manifolds may be characterized as almost HERMITian manifolds with symplectic or holomorphic local geodesic symmetries. We extend the notion of a local geodesic symmetry and in particular, give a similar characterization of all RIEMANNian locally s‐regular manifolds with an s‐structure of odd order.
Asymptotic Behaviour of an Empirical Nearest‐Neighbour Distance Function for Stationary Poisson Cluster Processes
Authors: Heinrich Lothar 
Published: May 2007

AbstractSummary. For stationary POISSONcluster processes (PCP's) Ø onRthe limit behaviour, asv(D)→ ∞, of the quantity\documentclass{article}\pagestyle{empty}\begin{document}$ \left({v\left(D \right)} \right)^{ - 1} \sum\limits_{x\varepsilon D:\phi \left({\left\{ x \right\}} \right) = 1} {\chi \left({x,r} \right)} $\end{document}, where χ(x, r) = 1, if Ø(b(x, r)) = 1, and χ(x, r) = 0 otherwise, is studied. A central limit theorem for fixedr> 0 and the weak convergence of the normalized and centred empirical process on [0,R] to a continuous GAUSSian process are proved. Lower and upper bounds for the nearest neighbour distance functionP1({φ:Y(b(0,r))≧1}) of a stationary PCP are given. Moreover, a representation of higher order Palm distributions of PCP's and a central limit theorem form‐dependent random fields with unboundedmare obtained. Both these auxiliary results seems to be of own interest.
Gender‐related and age‐related urinalysis of healthy subjects by NMR‐based metabonomics
Authors: Psihogios Nikolaos G. , Gazi Irene F. , Elisaf Moses S. , Seferiadis Konstantin I. , Bairaktari Eleni T. 
Published: May 2007

AbstractNMR‐based metabonomic analysis is a well‐established approach to characterizing healthy and diseased states. The aim of this study was to investigate inter‐individual variability in the metabolic urinary profile of a healthy Greek population, not subjected to strict dietary limitations, by NMR‐based metabonomics. The overall metabonomic urinalysis showed a homogeneous distribution among the population. The metabolic profile was examined in relation to gender and age, and reference intervals of major metabolites were determined. Multivariate data analysis led to the construction of two robust models that were able to predict the class membership of the subjects studied according to their gender and age. The most influential low molecular weight metabolites responsible for the differences in gender groups were citrate, creatinine, trimethylamine N‐oxide, glycine, creatine and taurine, and for the differences in age groups they were citrate, creatinine, trimethylamine N‐oxide and an unidentified metabolite (δ 3.78). Copyright © 2007 John Wiley & Sons, Ltd.
Identification of antioxidant phenolic compounds in feverfew (Tanacetum parthenium) by HPLC‐ESI‐MS/MS and NMR
Authors: Wu Changqing , Chen Feng , Wang Xi , Wu Yonnie , Dong Meidui , He Guoqing , Galyean Ronald D. , He Lilin , Huang Guohui 
Published: May 2007

AbstractAntioxidant polyphenolic acids in the medicinal herb feverfew (Tanacetum parthenium) were isolated through in vitro bioassay‐orientated antioxidant tests in response to 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH•) free radical scavenging and Fe2+‐chelating activities. Purification of the active compounds and their structural elucidation involved a variety of techniques including open‐column chromatography, HPLC, GC‐MS, LC‐MS and NMR. Major compounds with potent DPPH• scavenging activities were characterised as 3,5‐, 4,5‐ and 3,4‐di‐O‐caffeoylquinic acids (DCQAs). This is the first report of DCQAs found in feverfew. Copyright © 2007 John Wiley & Sons, Ltd.
Determination of pseudojujubogenin glycosides from Brahmi based on immunoassay using a monoclonal antibody against bacopaside I
Authors: Phrompittayarat Watoo , Putalun Waraporn , Tanaka Hiroyuki , Jetiyanon Kanchalee , Wittaya‐Areekul Sakchai , Ingkaninan Kornkanok 
Published: May 2007

AbstractBacopa monnieri (L.) Wettst. (Brahmi) is an Ayurvedic medicinal plant used for centuries as a memory enhancer. Dammarane‐type triterpenoid saponins classified as pseudojujubogenin and jujubogenin glycosides are reported as the active components in this plant. In this study, the monoclonal antibody (MAb) against bacopaside I, a major pseudojujubogenin glycoside found in Brahmi, was produced and characterised. Bacopaside I was conjugated with bovine albumin serum to prepare an immunogen. Hybridomas secreting a monoclonal antibody against bacopaside I was produced by fusing splenocytes from an immunised mouse and SP2/0‐Ag14 myeloma cells. The results showed that the antibodies were raised specifically against pseudojujubonin glycosides. An enzyme‐linked immunosorbant assay (ELISA) using anti‐bacopaside I MAb was performed in the range of 1.95–62.5 ng/mL of bacopaside I, with a limit of detection of 0.5 ng/mL. The method was validated and the practical use of the ELISA for analysing saponin glycosides from Brahmi was demonstrated. Copyright © 2007 John Wiley & Sons, Ltd.
Moleküle in “Slow Motion”: Abbremsen und Speichern kalter Moleküle
Authors: van de Meerakker Bas , Meijer Gerard 
Published: May 2007

AbstractLangsame und damit sehr kalte Moleküle bieten eine ähnlich aufregende Perspektive wie ultrakalte Atome. Doch ihre Herstellung ist schwieriger, denn meist versagt die bei Atomen erfolgreiche Laserkühlung. Eine Möglichkeit bietet der Stark‐Verzögerer. Er arbeitet wie ein inverser Linearbeschleuniger und bremst über den Stark‐Effekt sogar elektrisch neutrale Moleküle ab. Diese langsamen Moleküle kann dann ein Speicherring aufnehmen oder eine elektrostatische Quadrupol‐Falle fast zum Stillstand bringen. Kollisionsexperimente zwischen langsamen OH‐Molekülen und Xe‐Atomen haben jüngst erste interessante Einblicke in diese Streuprozesse geliefert. Bei ihnen kann die Energie gerade noch ausreichen, um die quantisierten Rotationszustände der beteiligten Moleküle zu ändern.
Spiel, Satz und Sieg: Physik und Mathematik des Tennisspiels
Authors: Thaller Sigrid , Mathelitsch Leopold 
Published: May 2007

AbstractDie Energieübertragung zwischen Schläger und Ball hängt von den Schwingungseigenschaften beider ab, wichtig ist zudem der Auftreffpunkt des Balles auf der Schlägerfläche. Die Rotation des Balles in der Luft ermöglicht unterschiedliche Flugbahnen. Selbststabilisierende Schlagbewegungen können kleine Ungenauigkeiten des Spielers ausgleichen. Der Zufall beeinflusst die Gewinnchancen weniger als im Fußball. Die Phase der Spielerbewegungen relativ zueinander gibt Auskunft über den Spielverlauf.
Laser kühlen mechanische Oszillatoren
Authors: Kippenberg Tobias 
Published: May 2007

AbstractKürzlich ist es drei Forschungsgruppen erstmalig gelungen, mechanische Oszillatoren mit Hilfe von Laserlicht zu kühlen. Damit konnten sie die mehr als drei Jahrzehnte alten Vorhersagen des russischen Theoretikers Vladimir Braginsky bestätigen. Die neuartige Methode könnte es in Zukunft erlauben, mikroskopische Objekte in den quantenmechanischen Grundzustand zu kühlen.
Wenn Funken Wellen schlagen: Zum 150. Geburtstag von Heinrich Hertz
Authors: Wegener Martin 
Published: May 2007

AbstractMit seinen Karlsruher Experimenten zu elektromagnetischen Wellen hat Heinrich Hertz 1887 die Maxwellsche Theorie der Elektrodynamik bestätigt und zugleich den Grundstein für die heutige Informationsgesellschaft gelegt. Mit seinen Experimenten zum Photoeffekt aus dem gleichen Jahr hat er – ohne dass ihm dies klar sein konnte – auch die Grenzen der Maxwellschen Theorie aufgezeigt und eine Tür zum Photon sowie zur Photonik geöffnet. Und dabei hat das “Jahrhundert des Photons”, wie manche das 21. Jahrhundert nennen, mit Heinrich Hertz‘ 150. Geburtstag gerade erst begonnen.
Rinderpapier und andere Cellulosefolien
Authors: Vilgis Thomas 
Published: May 2007

AbstractBei klassischen Spionagefilmen, zu Zeiten als geheime Nachrichten noch über Papier vermittelt wurden, konnte immer wieder gelacht werden, sobald der gejagte Agent den Zettel rasch in den Mund schob, mühsam kaute und schluckte. Empfindliche Zuschauer beschlich ein ungutes Gefühl im Hals. Heutzutage spielt leichtes, knuspriges Esspapier eine gewichtige Rolle in der Molekularküche und führt uns in die physikalische Welt der Cellulosen.
Quantitative proteomic comparison of mouse peroxisomes from liver and kidney
Authors: Mi Jia , Kirchner Eva , Cristobal Susana 
Published: May 2007

AbstractThe peroxisome plays a central role in the catabolic and anabolic pathways that contribute to the lipid homeostasis. Besides this main function, this organelle has gained functional diversity. Although several approaches have been used for peroxisomal proteome analysis, a quantitative protein expression analysis of peroxisomes from different tissues has not been elucidated yet. Here, we applied a 2‐DE‐based method on mouse liver and kidney peroxisomal enriched fractions to study the tissue‐dependent protein expression. Ninety‐one spots were identified from the 2‐DE maps from pH 3.0–10.0 and 51 spots from the basic range corresponding to 31 peroxisomal proteins, 10 putative peroxisomal, 6 cytosolic, 17 mitochondrial and 1 protein from endoplasmic reticulum. Based on the identification and on the equivalent quality of both tissue preparations, the differences emerging from the comparison could be quantified. In liver, proteins involved in pathways such as α‐ and β‐oxidation, isoprenoid biosynthesis, amino acid metabolism and purine and pirimidine metabolism were more abundant whereas in kidney, proteins from the straight‐chain fatty acid β‐oxidation were highly expressed. These results indicate that tissue‐specific functional classes of peroxisomal proteins could be relevant to study peroxisomal cellular responses or pathologies. Finally, a web‐based peroxisomal proteomic database was built.
Antibody microarray‐based profiling of complex specimens: systematic evaluation of labeling strategies
Authors: Kusnezow Wlad , Banzon Virryan , Schröder Christoph , Schaal René , Hoheisel Jörg D. , Rüffer Sven , Luft Petra , Duschl Albert , Syagailo Yana V. 
Published: May 2007

AbstractAntibody microarrays have often had limited success in detection of low abundant proteins in complex specimens. Signal amplification systems improve this situation, but still are quite laborious and expensive. However, the issue of sensitivity is more likely a matter of kinetically appropriate microarray design as demonstrated previously. Hence, we re‐examined in this study the suitability of simple and inexpensive detection approaches for highly sensitive antibody microarray analysis. N‐hydroxysuccinimidyl ester (NHS)‐ and Universal Linkage System (ULS)‐based fluorescein and biotin labels used as tags for subsequent detection with anti‐fluorescein and extravidin, respectively, as well as fluorescent dyes were applied for analysis of blood plasma. Parameters modifying strongly the performance of microarray detection such as labeling conditions, incubation time, concentrations of anti‐fluorescein and extravidin and extent of protein labeling were analyzed and optimized in this study. Indirect detection strategies whether based on NHS‐ or ULS‐chemistries strongly outperformed direct fluorescent labeling and enabled detection of low abundant cytokines with many dozen‐fold signal‐to‐noise ratios. Finally, particularly sensitive detection chemistry was applied to monitoring cytokine production of stimulated peripheral T cells. Microarray data were in accord with quantitative cytokine levels measured by ELISA and Luminex, demonstrating comparable reliability and femtomolar range sensitivity of the established microarray approach.
A proteomic approach to studying the differentiation of neural stem cells
Authors: Skalnikova Helena , Halada Petr , Vodicka Petr , Motlik Jan , Rehulka Pavel , Hørning Ole , Chmelik Josef , Nørregaard Jensen Ole , Kovarova Hana 
Published: May 2007

AbstractThe mechanisms that regulate the maintenance of stem cell self‐renewal versus differentiation are complex and remain mostly unknown. Understanding neurogenesis and neural cell differentiation presents a unique challenge for the treatment of nervous system disorders. To gain more insight into molecular mechanisms of the differentiation of neural cells, we combined the advantage of porcine fetal neural stem cells (NSCs) in vitro differentiation model and proteomic analysis. Using 2‐DE followed by MS, we profiled constituent proteins of NSCs and their differentiated progenies at first and then indicated protein species that were significantly up‐ or down‐regulated during the differentiation. The largest identified group of constituent proteins was related to RNA and protein metabolism and processing, including chaperones, and the second largest consisted of proteins involved in cell organization (cytoskeleton and annexins). Differentiation of neural cells was found to be accompanied by changes in the expression of proteins involved in DNA and RNA binding, mRNA processing and transport, stress responses, iron storage, and redox regulation. Additional immunoblot analysis verified the induction of α‐B crystallin and heterogenous nuclear ribonucleoproteins (hnRNPs) A1 and A2/B1. Furthermore, immunocytochemistry demonstrated specific localization of α‐B crystallin in the cytoplasm or nucleus of glial cells and confirmed cellular expression patterns of hnRNPs A1 and A2/B1. These findings represent a significant step towards understanding neural cell differentiation and identification of the regulatory proteins associated with this process.
Evaluation of the substrate envelope hypothesis for inhibitors of HIV‐1 protease
Authors: Chellappan Sripriya , Kairys Visvaldas , Fernandes Miguel X. , Schiffer Celia , Gilson Michael K. 
Published: May 2007

AbstractCrystallographic data show that various substrates of HIV protease occupy a remarkably uniform region within the binding site; this region has been termed the substrate envelope. It has been suggested that an inhibitor that fits within the substrate envelope should tend to evade viral resistance because a protease mutation that reduces the affinity of the inhibitor will also tend to reduce the affinity of substrate, and will hence decrease the activity of the enzyme. Accordingly, inhibitors that fit the substrate envelope better should be less susceptible to clinically observed resistant mutations, since these must also allow substrates to bind. The present study describes a quantitative measure of the volume of a bound inhibitor falling outside the substrate envelope, and observes that this quantity correlates with the inhibitor's losses in affinity to clinically relevant mutants. This measure may thus be useful as a penalty function in the design of robust HIV protease inhibitors. Proteins 2007. © 2007 Wiley‐Liss, Inc.
A brief review of Phase 1 and Clinical Pharmacology statistics in clinical drug development
Authors: Patterson Scott D. , Jones Byron 
Published: May 2007

AbstractFollowing a brief description of historical Phase 1 research, Clinical Pharmacology studies, and the role of statistics in this setting, Phase 1 study design and statistical analysis are reviewed. A description of design and analysis for Clinical Pharmacology studies is also provided, and the role of statistics in this area of drug development in the future is discussed. While challenging, this area of statistics in drug development is likely to have an active and engaging future. Copyright © 2007 John Wiley & Sons, Ltd.
Stabilization of single‐input nonlinear systems using higher‐order term compensating sliding mode control
Authors: Voytsekhovsky Dmitry , Hirschorn Ronald M. 
Published: May 2007

AbstractIn this work we investigate a new approach for stabilizing nonlinear systems using sliding mode control. The idea behind this method is the following: given an approximately feedback linearizable system, we define a local coordinate transformation and then find a sliding mode controller, in the new coordinates, which steers the state to the origin. Our results are compared to those obtained using approximate feedback linearization‐based sliding mode control. Copyright © 2007 John Wiley & Sons, Ltd.