bluuebunny/crossref_metadata_2025 huggingface dataset:
High‐dose therapy and autologous peripheral blood stem cells transplantation followed by a very low reduced intensity regimen with fludarabine + cyclophosphamide and allograft improve complete remission rate in de novo multiple myeloma patients
Authors: Martino Massimo , Console Giuseppe , Irrera Giuseppe , Praticò Giulia , Stelitano Caterina , Callea Vincenzo , Morabito Fortunato , Quartarone Eugenia , Musolino Caterina , Piro Eugenio , Brugiatelli Maura , Iacopino Pasquale
Published: August 2006

The recent development of reduced intensity conditioning and allotransplantation (RICT) has opened a new way to assure engraftment of donor cells while reducing early transplant‐related mortality. We evaluated the combination of high‐dose therapy and autologous peripheral blood stem cells transplantation (APBSCT) followed by RICT to extend the benefit of allografting procedures in de novo multiple myeloma (MM) patients. Fifteen subjects with stage III MM (median age 51 years, range 40–57) received high dose melphalan (200 mg/m2) followed by APBSCT previously collected after cyclophosphamide (4 g/m2) and granulocyte colony‐stimulating factor (G‐CSF). After 3–4 months from APBSCT, the patients underwent RICT, consisting of fludarabine 30 mg/m2 + cyclophosphamide 300 mg/m2 on days −4, −3, and −2. Acute graft‐versus‐host disease (GVHD) occurred in 2 patients; 6 patients developed chronic GVHD; 4 patients developed CMV antigenemia and were treated pre‐emptively with ganciclovir. No transplant related mortality was shown. Response was simultaneously measured by both electrophoresis (EP) and immunofixation (IF); when IF was negative, patients were classified in complete remission (CR) and when it remained positive, near CR (nCR). After a median follow up of 44 months post APBSCT, 100 and 43% of patients are still alive and progression‐free, respectively. Overall, the CR + nCR rate after dose‐reduced allograft was enhanced from 26.7 to 73.3%. A correlation not statistically significant between GVHD and remission was found. In conclusion, an up‐front tandem strategy with a very low reduced intensity‐conditioning regimen for allografting following autografting is feasible and induces high CR/nCR rate in MM. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
User preference: A measure of query‐term quality
Authors: Wacholder Nina , Liu Lu
Published: August 2006

The goal of this research is to understand what characteristics, if any, lead users engaged in interactive information seeking to prefer certain sets of query terms. Underlying this work is the assumption that query terms that information seekers prefer induce a kind of cognitive efficiency: They require less mental effort to process and therefore reduce the energy required in the interactive information‐seeking process. Conceptually, this work applies insights from linguistics and cognitive science to the study of query‐term quality. We report on an experiment in which we compare user preference for three sets of terms; one had been preconstructed by a human indexer, and two were identified automatically. Twenty‐four participants used a merged list of all terms to answer a carefully created set of questions. By design, the interface constrained users to access the text exclusively via the displayed list of query terms. We found that participants displayed a preference for the human‐constructed set of terms eight times greater than the preference for either set of automatically identified terms. We speculate about reasons for this strong preference and discuss the implications for information access. The primary contributions of this research are (a) explication of the concept of user preference as a measure of query‐term quality and (b) identification of a replicable procedure for measuring preference for sets of query terms created by different methods, whether human or automatic. All other factors being equal, query terms that users prefer clearly are the best choice for real‐world information‐access systems.
Fluorescence and bioluminescence analysis of sequential UV‐biological degradation of p‐cresol in water
Authors: Tchaikovskaya O. , Sokolova I. , Svetlichnyi V. , Karetnikova E. , Fedorova E. , Kudryasheva N.
Published: August 2006

The photolysis and Penicillium tardum H‐2 degradation of p‐cresol in water containing humic acids was investigated by fluorescence and bioluminescence methods. Humic acids extracted from peat (the Vasuygan bog, Tomsk region of Russia) induce the phototransformation of p‐cresol. The influence of humic acids on the phototransformation of p‐cresol under different irradiation conditions was investigated. Comparison of the data on the KrCl* (λ = 222 nm) and XeCl* (λ = 308 nm) excilamps light showed that the most effective p‐cresol degradation was observed with mercury lamp irradiation in the presence of humic acids. Copyright © 2006 John Wiley & Sons, Ltd.
Peptide design of a competitive inhibitor for HMG‐CoA reductase based on statin structure
Authors: Pak Valeriy V. , Kim Sung Hee , Koo Minseon , Lee Nari , Shakhidoyatov K. M. , Kwon Dae Young
Published: August 2006

This study investigates a proposed design of a peptide sequence that is based on a bioactive conformation of statins that act as the competitive inhibitors of HMG–CoA for HMGR. To bridge these heterogeneous organic compounds, a conformational aspect relating to an analysis of the flexibility of the peptide molecules and their occupied volumes was applied to the peptide design. The design criterion was formulated in terms of a proximity parameter (Pr), reflecting the probability of an active peptide conformation to approximate the statin. Through a structure–functional analysis of previously synthesized peptides and statin molecules, nine peptides were selected for the peptide library. Comparing the calculated proximity parameters, four peptides (IAVE, YAVE, IVAE, and YVAE) from the library were selected and synthesized. In vitro assays elucidated the inhibition properties for HMGR that are exhibited by these peptides. Among all peptides, YVAE showed the highest ability to inhibit HMGR. A kinetic analysis revealed that this peptide is a competitive inhibitor of HMG–CoA with an equilibrium constant of inhibitor binding (Ki) of 15.2 ± 1.4 μM. The calculated coefficient correlation (R) between log (IC50) and the inverse value of proximity parameter (1/Pr) was found to be 0.99, indicating a high degree of correlation and efficacy of the given approach in the peptide sequence design. © 2006 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 84: 586–594, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Vibrational spectroscopic characteristics of secondary structure polypeptides in liquid water: Constrained MD simulation studies
Authors: Choi Jun‐Ho , Hahn Seungsoo , Cho Minhaeng
Published: August 2006

Using the constrained MD simulation method in combination with quantum chemistry calculation, Hessian matrix reconstruction, and fragmentation approximation methods, we established a computational scheme for numerical simulations of amide I IR absorption, vibrational circular dichroism (VCD), and 2D IR photon echo spectra of peptides in solution. Six different secondary structure peptides, i.e., α‐helix, 310‐helix, π‐helix, antiparallel and parallel β‐sheets, and polyproline II (PII), are considered, and the vibrational characteristic features in their linear and nonlinear spectra in the amide I band region are discussed. Isotope‐labeling effects on IR and VCD spectra are notable only for α‐ and π‐helical peptides due to the strong vibrational couplings between two nearest neighboring amide I local oscillators. The amplitudes of difference 2D IR spectra are shown to be strongly dependent on both the extent of mode delocalization and the relative orientation of local mode transition dipoles determined by secondary structure. © 2006 Wiley Periodicals, Inc. Biopolymers 83: 519–536, 2006

This article was originally published online as an accepted preprint. The “Published Online“ date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Randomized clinical trial assessing the effect of Doppler-optimized fluid management on outcome after elective colorectal resection
Authors: Noblett S E , Snowden C P , Shenton B K , Horgan A F
Published: August 2006

Background

Protocolized fluid administration using oesophageal Doppler monitoring may improve the postoperative outcome in patients undergoing surgery.

Methods

A total of 108 patients undergoing elective colorectal resection were recruited into a double-blind prospective randomized controlled trial. An oesophageal Doppler probe was placed in all patients. The control group received perioperative fluid at the discretion of the anaesthetist, whereas the intervention group received additional colloid boluses based on Doppler assessment. Primary outcome was length of postoperative hospital stay. Secondary outcomes were morbidity, return of gastrointestinal function and cytokine markers of the systemic inflammatory response. Standard preoperative and postoperative management was used in all patients.

Results

Demographic and surgical details were similar in the two groups. Aortic flow time, stroke volume, cardiac output and cardiac index during the intraoperative period were higher in the intervention group (P < 0·050). The intervention group had a reduced postoperative hospital stay (7 versus 9 days in the control group; P = 0·005), fewer intermediate or major postoperative complications (2 versus 15 per cent; P = 0·043) and tolerated diet earlier (2 versus 4 days; P = 0·029). There was a reduced rise in perioperative level of the cytokine interleukin 6 in the intervention group (P = 0·039).

Conclusion

A protocol-based fluid optimization programme using intraoperative oesophageal Doppler monitoring leads to a shorter hospital stay and decreased morbidity in patients undergoing elective colorectal resection.
A Simple and Powerful Flow Cytometric Method for the Simultaneous Determination of Multiple Parameters at G Protein‐Coupled Receptor Subtypes
Authors: Schneider Erich , Mayer Matthias , Ziemek Ralf , Li Liantao , Hutzler Christoph , Bernhardt Günther , Buschauer Armin
Published: August 2006

The quantification of pharmacological parameters at G protein‐coupled receptors (GPCRs) is indispensable in drug research but costly and time‐consuming when conventional methods are sequentially applied. With neuropeptide Y (NPY) Y1, Y2, and Y5 receptors as model systems, a homogenous flow cytometric method for the simultaneous determination of the affinity, selectivity, and activity of GPCR ligands was developed. Mixtures of cells expressing the receptors of interest and cyanine‐labeled NPY as a universal fluorescent Y1, Y2, and Y5 receptor agonist were used. Calcium mobilization was measured in different channels with the aid of fluo‐4 and fura red. A combination of dye‐loaded HEL‐Y1 and CHO‐Y2‐Gαqi5 cells with unloaded HEC‐1B‐Y5 cells allowed the simultaneous determination of Y1, Y2, and Y5 receptor selectivity preceded by the Y1 and Y2 receptor‐mediated response with one and the same sample. The data are in good agreement with those determined by radioligand binding and spectrofluorimetry. The convenient, robust, and inexpensive multiparametric procedure offers a broad range of applications in the pharmacological characterization of GPCR ligands.
Molecular Basis of Substrate Recognition in D‐3‐Hydroxybutyrate Dehydrogenase from Pseudomonas putida
Authors: Feller Claudia , Günther Robert , Hofmann Hans‐Jörg , Grunow Marlis
Published: August 2006

D‐3‐Hydroxybutyrate dehydrogenase from Pseudomonas putida (EC 1.1.1.30) belongs to the family of short‐chain dehydrogenases/reductases (SDRs). It catalyzes the reversible and stereospecific oxidation of D‐3‐hydroxybutyrate (D‐3‐HB) to acetoacetate with the aid of NAD+ as coenzyme. This study contributes to understanding the mechanism and the high specificity of this enzyme towards its negatively charged and hydrophilic substrate. Sequence comparison of 44 bacterial HBDHs shows the residues Gln91, His141, Lys149, Lys192, and Gln193 to be strictly conserved. Site‐directed mutagenesis of these amino acids to alanine and subsequent kinetic characterization of the mutated enzymes provides insight into the importance of these residues for substrate recognition and catalysis. Docking studies and molecular‐dynamics simulations based on a three‐dimensional structure model of a complex between P. putida HBDH and its coenzyme obtained by comparative molecular modeling were performed and provided deeper insight into the binding of the ligands at the molecular level. They show the residues Gln91, His141, Gln193, and, in particular, Lys149 to be involved in a hydrogen‐bonding network with the carboxylate group of the substrate.
Silica Pattern Formation in Diatoms: Species‐Specific Polyamine Biosynthesis
Authors: Sumper Manfred , Lehmann Gerhard
Published: August 2006

Diatoms are eukaryotic, unicellular algae that are well known for the intricate architecture of their silica‐based cell walls. Species identification is mainly based on variations of their hierarchically organized silica structures. Particularly striking silica frameworks are found among diatoms that belong to the genus Coscinodiscus. Recent work indicates an important role for long‐chain polyamines in guiding silica precipitation as well as in silica‐pattern formation. Here we demonstrate that polyamines, even if isolated from closely related diatom species, exhibit substantial structural differences. Structural variations include the overall chain length, the degree of methylation, positions of secondary amino functionalities, and, unexpectedly, site‐specific incorporation of a quaternary ammonium functionality. These findings support a specific role for polyamines in creating silica nanostructures.
Kinetic, Thermodynamic, and Mechanistic Patterns for Free (Unbound) Cytochrome c at Au/SAM Junctions: Impact of Electronic Coupling, Hydrostatic Pressure, and Stabilizing/Denaturing Additives
Authors: Khoshtariya Dimitri E. , Dolidze Tina D. , Seifert Stefan , Sarauli David , Lee Geoffrey , van Eldik Rudi
Published: August 2006

Combined kinetic (electrochemical) and thermodynamic (calorimetric) investigations were performed for an unbound (intact native‐like) cytochrome c (CytC) freely diffusing to and from gold electrodes modified by hydroxyl‐terminated self‐assembled monolayer films (SAMs), under a unique broad range of experimental conditions. Our approach included: 1) fine‐tuning of the charge‐transfer (CT) distance by using the extended set of Au‐deposited hydroxyl‐terminated alkanethiol SAMs [‐S‐(CH2)n‐OH] of variable thickness (n=2, 3, 4, 6, 11); 2) application of a high‐pressure (up to 150 MPa) kinetic strategy toward the representative Au/SAM/CytC assemblies (n=3, 4, 6); 3) complementary electrochemical and microcalorimetric studies on the impact of some stabilizing and denaturing additives. We report for the first time a mechanistic changeover detected for “free” CytC by three independent kinetic methods, manifested through 1) the abrupt change in the dependence of the shape of the electron exchange standard rate constant (ko) versus the SAM thickness (resulting in a variation of estimated actual CT range within ca. 15 to 25 Å including ca. 11 Å of an “effective” heme‐to‐ω‐hydroxyl distance). The corresponding values of the electronic coupling matrix element vary within the range from ca. 3 to 0.02 cm−1; 2) the change in activation volume from +6.7 (n=3), to ≈0 (n=4), and −5.5 (n=6) cm3 mol−1 (disclosing at n=3 a direct pressure effect on the protein's internal viscosity); 3) a “full” Kramers‐type viscosity dependence for ko at n=2 and 3 (demonstrating control of an intraglobular friction through the external dynamic properties), and its gradual transformation to the viscosity independent (nonadiabatic) regime at n=6 and 11. Multilateral cross‐testing of “free” CytC in a native‐like, glucose‐stabilized and urea‐destabilized (molten‐globule‐like) states revealed novel intrinsic links between local/global structural and functional characteristics. Importantly, our results on the high‐pressure and solution‐viscosity effects, together with matching literature data, strongly support the concept of “dynamic slaving”, which implies that fluctuations involving “small” solution components control the proteins' intrinsic dynamics and function in a highly cooperative manner as far as CT processes under adiabatic conditions are concerned.
Acid–Base and Metal‐Ion‐Binding Properties of Xanthosine 5′‐Monophosphate (XMP) in Aqueous Solution: Complex Stabilities, Isomeric Equilibria, and Extent of Macrochelation
Authors: Sigel Helmut , Massoud Salah S. , Song Bin , Griesser Rolf , Knobloch Bernd , Operschall Bert P.
Published: August 2006

The four acidity constants of threefold protonated xanthosine 5′‐monophosphate, H3(XMP)+, reveal that at the physiological pH of 7.5 (XMP−H)3− strongly dominates (and not XMP2− as given in textbooks); this is in contrast to the related inosine (IMP2−) and guanosine 5′‐monophosphate (GMP2−) and it means that XMP should better be named as xanthosinate 5′‐monophosphate. In addition, evidence is provided for a tautomeric (XMP−H⋅N1)3−/(XMP−H⋅N3)3− equilibrium. The stability constants of the M(H;XMP)+ species were estimated and those of the M(XMP) and M(XMP−H)− complexes (M2+=Mg2+, Ca2+, Sr2+, Ba2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+) measured potentiometrically in aqueous solution. The primary M2+ binding site in M(XMP) is (mostly) N7 of the monodeprotonated xanthine residue, the proton being at the phosphate group. The corresponding macrochelates involving P(O)2(OH)− (most likely outer‐sphere) are formed to ≈65 % for nearly all M2+. In M(XMP−H)− the primary M2+ binding site is (mostly) the phosphate group; here the formation degree of the N7 macrochelates varies widely from close to zero for the alkaline earth ions, to ≈50 % for Mn2+, and ≈90 % or more for Co2+, Ni2+, Cu2+, Zn2+, and Cd2+. Because for (XMP−H)3− the micro stability constants quantifying the M2+ affinity of the xanthosinate and ${{\rm PO}{{2- \hfill \atop 3\hfill}}}$ residues are known, one may apply a recently developed quantification method for the chelate effect to the corresponding macrochelates; this chelate effect is close to zero for the alkaline earth ions and it amounts to about one log unit for Co2+, Ni2+, Cu2+. This method also allows calculation of the formation degrees of the monodentatally coordinated isomers; this information is of relevance for biological systems because it demonstrates how metal ions can switch from one site to another through macrochelate formation. These insights are meaningful for metal‐ion‐dependent reactions of XMP in metabolic pathways; previous mechanistic proposals based on XMP2− need revision.
A New Basic Motif in Cyanometallate Coordination Polymers: Structure and Magnetic Behavior of M(μ‐OH2)2[Au(CN)2]2(M=Cu, Ni)
Authors: Lefebvre Julie , Callaghan Fergal , Katz Michael J. , Sonier Jeff E. , Leznoff Daniel B.
Published: August 2006

The structures of two cyanoaurate‐based coordination polymers, M(μ‐OH2)2[Au(CN)2]2(M=Cu, Ni), were determined by using a combination of powder and single‐crystal X‐ray diffraction techniques. The basic structural motif for both polymers contains rarely observed M(μ‐OH2)2M double aqua‐bridges, which generate an infinite chain; twotrans[Au(CN)2]−units also dangle from each metal center. The chains form ribbons that interact three dimensionally through CN⋅⋅⋅H hydrogen bonding. The magnetic properties of both compounds and of the dehydrated analogue Cu[Au(CN)2]2were investigated by direct current (dc) and alternating current (ac) magnetometry; muon spin‐relaxation data was also obtained to probe their magnetic properties in zero‐field. In M(μ‐OH2)2[Au(CN)2]2, ferromagnetic chains of M(μ‐OH2)2M are present below 20 K. Interchain magnetic interactions mediated through hydrogen bonding, involving water and cyanoaurate units, yield a long‐range magnetically ordered system in Cu(μ‐OH2)2[Au(CN)2]2below 0.20 K, as indicated by precession in the muon spin polarization decay. Ni(μ‐OH2)2[Au(CN)2]2undergoes a transition to a spin‐glass state in zero‐field at 3.6 K, as indicated by a combination of muon spin‐relaxation and ac‐susceptibility data. This transition is probably due to competing interactions that lead to spin frustration. A phase transition to a paramagnetic state is possible for Ni(μ‐OH2)2[Au(CN)2]2upon application of an external field; the critical field was determined to be 700 Oe at 1.8 K. The dehydrated compound Cu[Au(CN)2]2shows weak antiferromagnetic interactions at low temperatures.
Investigation of a Molecular Morphology Effect on Polyphenylazomethine Dendrimers; Physical Properties and Metal‐Assembling Processes
Authors: Imaoka Takane , Tanaka Reiko , Yamamoto Kimihisa
Published: August 2006

A series of novel dendritic polyphenylazomethines (DPA) with asymmetric morphologies was synthesized. Their physical properties, such as encapsulating effect, molecular dynamics, and metal assembly, are strongly dependent on the entire conformation of the molecules. The most important property is layer‐by‐layer metal assembly in the dendrimer structure from the core to the outside. Bis‐ and tris‐substituted DPAs of the fourth generation also act as frameworks for stepwise assembly of a metal component (SnCl2), like the fully substituted symmetric DPA. However, extensive investigation of metal assembly in specific DPAs revealed that they do not follow the stepwise process. The molecular density calculated from the experimental hydrodynamic volume indicated that bis‐ and tris‐substituted DPAs with asymmetric morphology still retain a free space similar to that of fully substituted symmetric DPA. The monosubstituted DPA, however, displayed a slightly higher density (smaller space) than the other DPAs. The experimental results suggest a bent conformation of the dendrimer in which the core moiety is folded into the dendron structure. In addition, the molecular dynamics were probed by means of the 1H NMR signals of the porphyrin core. It was demonstrated that the conformation is not fixed at room temperature in solvated DPAs, especially in monosubstituted DPA. A similar observation was for the smaller DPAs (third generations) with asymmetric morphologies. These dendrimers do not follow the stepwise complexation process. The structures of bis‐ and tris‐substituted dendrimers which accurately follow the stepwise process are fixed. These observations provide a new insight into the finely controlled metal‐assembly chemistry of dendritic macromolecules, and a rigid and fixed conformation is one of important factors for their unique properties.
Cover Picture: Exploring and Expanding the Structural Diversity of Self‐Assembling Dendrons through Combinations of AB, Constitutional Isomeric AB2, and AB3 Biphenyl‐4‐Methyl Ether Building Blocks (Chem. Eur. J. 24/2006)
Authors: Percec Virgil , Holerca Marian N. , Nummelin Sami , Morrison John J. , Glodde Martin , Smidrkal Jan , Peterca Mihai , Rosen Brad M. , Uchida Satoshi , Balagurusamy Venkatachalapathy S. K. , Sienkowska Monika J. , Heiney Paul A.
Published: August 2006

Seven libraries with up to three generations of amphiphilic dendrons based on AB, constitutional isomeric AB2, and AB3 biphenyl‐4‐methyl ether building blocks were synthesized by Percec et al., as described on page 6216ff., and analyzed by using the retrostructural analysis method shown. These dendrons self‐assemble into hollow and non‐hollow supramolecular dendrimers up to twice as large as those for the architecturally related benzyl ether. These results expand the structural diversity of non‐hollow and hollow supramolecular dendrimers and demonstrate the generality of self‐assembling dendrons based on amphiphilic arylmethyl ethers.
Alternative Einsatzmöglichkeiten der „Bevorzugten Kristallisation”︁ zur Enantiomerentrennung
Authors: Polenske D. , Elsner M. P. , Lorenz H. , Seidel‐Morgenstern A.
Published: August 2006

Die Enantiomerentrennung aus racemischen Mischungen mittels der „Bevorzugten Kristallisation”︁ wird bisher ausschließlich bei konglomeratbildenden Stoffsystemen im Batch‐ bzw. in einigen Fällen im zyklischen Modus durchgeführt. Für die wesentlich häufiger vorkommenden verbindungsbildenden Stoffsysteme wurde die „Bevorzugte Kristallisation”︁ bisher nicht eingesetzt. Der Beitrag gibt einen Überblick über die Möglichkeiten und Grenzen der Enantiomerentrennung in konglomerat‐ und verbindungsbildenden Stoffsystemen mittels der „Bevorzugten Kristallisation”︁. Dabei wird auf den Einfluss der Fest/Flüssig‐Phasengleichgewichte‐ sowie auf alternative Konzepte der Prozessführung eingegangen. Für das konglomeratbildende Stoffsystem Threonin/Wasser werden experimentelle Ergebnisse zur Maßstabsvergrößerung des Batch‐Prozesses sowie zur zyklischen Betriebsweise vorgestellt. Des Weiteren werden erste erfolgreiche Resultate zum Einsatz der „Bevorzugten Kristallisation”︁ zur Enantiomerengewinnung im verbindungsbildenden Stoffsystem Mandelsäure/Wasser präsentiert.
Temperatur‐ und Wasserverteilung bei der konvektiven Trocknung mittels Inline‐Magnetresonanztomographie
Authors: Regier M. , Idda P. , Knoerzer K. , Hardy E. H. , Schuchmann H. P.
Published: August 2006

Mit Hilfe eines Konvektionstrockners ist die Trocknung von Lebensmitteln direkt in einem Magnetresonanztomographen möglich. Dabei können Wasserverteilungen innerhalb eines Trocknungsgutes inline und nicht‐invasiv erfasst werden. So lässt sich die ortsaufgelöste Trocknung verfolgen, und es können bestehende und neue Trocknungsmodelle evaluiert werden.
Doing Homogeneous Catalysis between Basic Research and Application
Authors: Beller M.
Published: August 2006

Recent achievements in applied homogeneous catalysis are described. Special focus is given on the development of novel palladium catalysts which are of industrial interest for the synthesis of bulk and fine chemicals. Most of the reported work has been done in an intensive collaboration between the Degussa AG (DHC) and the Leibniz‐Institut für Katalyse e.V. The clear vision of the goal and a close interaction of basic research and applied catalysis have led to a fast development from the initial discovery to the upscaling of the ligands. Such a combination of know how from academic and industrial partners will provide the basis for further innovations in catalysis in future.
Die Rolle der Chemokatalyse bei der Etablierung der Technologieplattform „Nachwachsende Rohstoffe”︁
Authors: Claus P. , Vogel G. H.
Published: August 2006

Die Bundesrepublik Deutschland besitzt keinen kostengünstigen Zugang zu Erdöl. Daher ist es eine wichtige Zukunftsaufgabe, eine post‐fossile, nachhaltige Ära der Stoffwirtschaft zu organisieren und neue Verfahren basierend auf alternativen Kohlenstoffquellen zu entwickeln. Die Änderung der Rohstoffbasis ist für die chemische Industrie keine neue Erfahrung, immer wurden damit eine Innovationswelle und ein Aufschwung angestoßen. Eine Voraussetzung ist es, frühzeitig die wissenschaftlichen und technologischen Grundlagen für die neue und gleichzeitig doch uralte Rohstoffbasis Biomasse zu entwickeln und das vorhandene Know‐how der Petrochemie insbesondere auf dem Gebiet der Chemokatalyse zu nutzen.
Berechnung physikalischer Gaslöslichkeiten in verschiedenen Lösungsmitteln mit COSMO‐RS
Authors: Miltner M. , Miltner A. , Friedl A.
Published: August 2006

Die Ermittlung verlässlicher Phasengleichgewichtsinformationen gehört zu den wichtigsten Problemstellungen der Mischphasenthermodynamik. Neben den klassischen Verfahren gewinnen quantenchemische a‐priori‐Methoden, die ohne experimentell angepasste Parameter auskommen, immer mehr an Bedeutung. In dieser Arbeit soll die Anwendbarkeit einer solchen Methode – COSMO‐RS – für die Berechnung der in Trenntechnik und Umwelttechnik relevanten physikalischen Gaslöslichkeit beurteilt werden.
Modellierung der Verbackung von Schüttgütern
Authors: Brendel L.
Published: August 2006

Zur Modellierung des Verbackungsverhaltens von Schüttgütern ist neben der Kenntnis der mikromechanischen Belastungseigenschaften eines Teilchenkontakts die Anwendbarkeit eben dieser Kenntnis in einer Vielteilchensimulation nötig, um auf das Verhalten eines Haufwerks schließen zu können. Es wird ein für dreidimensionale DEM‐Simulationen (runder Teilchen) geeignetes Kontaktkraftgesetz inklusive des Maximalbelastungskriteriums vorgestellt. Damit erzielte Ergebnisse werden dargelegt und mit experimentellen Daten verglichen.
Monolithischer Palladium‐Trägerkatalysator – Herstellung und technische Verwendung
Authors: Bauer T. , Schubert M. , Lange R.
Published: August 2006

Festbettreaktoren mit monolithischem Trägerkatalysator stellen eine interessante Alternative zu konventionellen Suspensionsreaktoren und regellos gepackten Festbettreaktoren für katalytische Gas/Flüssig‐Reaktionen dar. Dieser Beitrag diskutiert die Herstellung von monolithischen Palladium‐Trägerkatalysatoren und die technische Verwendung am Beispiel der Hydrierung von alpha‐Methylstyrol zu Cumol unter ausgewählten Betriebsbedingungen.
Activation of Light Alkanes on Sulfated Zirconia
Authors: Olindo R. , Li X. , Lercher J. A.
Published: August 2006

The present contribution reviews recent experiments of our group towards the synthesizing and understanding of highly reactive sulfate‐modified zirconia. It is shown that in the absence of Pt, the catalytic activity depends upon the ability to oxidize a small fraction of the alkanes to alkenes. The alkenes form sec‐carbenium ions with Brønsted acid sites and isomerize via carbenium ion/alkoxy intermediates. Alkane activation/conversion propagates through hydride transfer from n‐butane to the tert‐butyl carbenium ion. A kinetic model accounting for the elementary steps is proposed and catalyst preparation strategies are reported.
Structure–Activity Relationship Studies on the Immune Stimulatory Effects of Base‐Modified CpG Toll‐Like Receptor 9 Agonists
Authors: Jurk Marion , Kritzler Andrea , Debelak Harald , Vollmer Jörg , Krieg Arthur M. , Uhlmann Eugen
Published: August 2006

Synthetic oligodeoxynucleotides containing unmethylated deoxycytidylyl‐deoxyguanosine dinucleotide (CpG) motifs are able to stimulate potent immune responses through a signaling pathway involving Toll‐like receptor 9 (TLR9). We have investigated the structure–activity relationship (SAR) of base‐modified CpG oligonucleotides with TLR9 by measuring TLR9 activation by 20‐mer oligonucleotides having just a single human recognition motif (5′‐GTCGTT‐3′) in functional cell‐based TLR9 assays. Substitution of guanine by hypoxanthine and 6‐thioguanine resulted in activity similar to the unmodified parent molecule, whereas purine, 2‐aminopurine, 2,6‐diaminopurine, and 8‐oxo‐7,8‐dihydroguanine substitution resulted in approximately 40–60 % reduction in activity, and 7‐deazaguanine substitution led to the strongest (80 %) reduction in TLR9 stimulation. Furthermore, none of the investigated modifications at C5 and N4 of cytosine were well tolerated with respect to human TLR9 stimulation. Our results are compatible with a SAR model in which guanine is recognized by the Hoogsteen site, and C5 is most critical for recognition of cytosine. In addition, we found significant species‐specific differences between human and murine TLR9 recognition, which demonstrates the importance of choosing appropriate assay systems for SAR studies.
Helicobacter Connections
Authors: Marshall Barry
Published: August 2006

After preliminary studies in 1981, Marshall and Warren conducted a study in which the new bacterium Helicobacter pylori was cultured. In that series, 100 % of 13 patients with duodenal ulcer were found to be infected. The hypothesis that peptic ulcer was caused by a bacterial infection was not accepted without a fight. Most experts believed that Helicobacter was a harmless commensal, infecting people who had ulcers for some other reason. In response, Marshall drank a culture of Helicobacter to prove that the bacteria could infect a healthy person and cause gastritis. The truth behind peptic ulcers was revealed; that is, very young children acquired the Helicobacter organism, leading to a chronic infection which caused a lifelong susceptibility to peptic ulcers. Marshall developed new treatments for the infection and diagnostic tests which allowed the hypothesis to be evaluated and proven. After 1994 Helicobacter was generally accepted as the cause of most gastroduodenal diseases including peptic ulcer and gastric cancer. As a result of this knowledge, treatment is a simple procedure, and stomach surgery has become a rarity.
Elevated mRNA levels of DNA methyltransferase‐1 as an independent prognostic factor in primary nonsmall cell lung cancer
Authors: Kim Hojoong , Kwon Young Mi , Kim Jin Seuk , Han Joungho , Shim Young Mog , Park Joobae , Kim Duk‐Hwan
Published: August 2006

BACKGROUND.

Despite many reports about the involvement of DNA methyltransferases (DNMTs) in human cancers, including nonsmall cell lung cancer (NSCLC), the clinicopathologic significance of DNMTs in primary NSCLC remains to be elucidated.

METHODS.

The relation between the mRNA levels of DNMTs (1 and 3b) and the promoter methylation of the p16, RARβ2, H‐cadherin, GSTP1, RIZ, and FHIT genes and the clinicopathologic features in 102 fresh‐frozen tissues and paraffin blocks were retrospectively studied. The mRNA levels of the DNMTs were assessed via semiquantitative reverse‐transcription polymerase chain reaction (RT‐PCR), and the methylation status of the CpG islands were determined by methylation‐specific PCR.

RESULTS.

The mRNA levels of DNMT1 and DNMT3b were elevated in 53% and 58% of 102 NSCLCs, respectively. Hypermethylation of p16, RARβ2, H‐cadherin, GSTP1, RIZ, and FHIT occurred in 37%, 38%, 34%, 18%, 9%, and 31% of patients, respectively. Univariate analysis showed that elevated DNMT mRNA levels were not significantly associated with the hypermethylation of 6 genes. However, the elevated mRNA levels of DNMT1 were determined to be significantly associated with the hypermethylation of the p16 promoter (odds ratio [OR] = 2.70, 95% confidence interval [95% CI], 1.02–7.15; P = .02), after controlling for age, gender, pack‐years smoked, histology, and pathologic stage. The hazard of failure in cases with elevated mRNA levels of DNMT1 was 3.51 (95% CI, 1.18–12.76; P = .02) times higher than that in those without. The elevated mRNA levels of DNMT3b were not ultimately associated with patient prognosis.

CONCLUSIONS.

Elevated mRNA expression of DNMT1 may be an independent prognostic factor in NSCLC and CpG island hypermethylation in NSCLC may be maintained by a complex interaction of several factors rather than by a simple transcriptional up‐regulation of DNMT1. Cancer 2006. © 2006 American Cancer Society.
Vibrational Structure of Endohedral Fullerene Sc3N@C78 (D3h′): Evidence for a Strong Coupling between the Sc3N Cluster and C78 Cage
Authors: Krause Matthias , Popov Alexey , Dunsch Lothar
Published: August 2006

The vibrational structure of the endohedral cluster fullerene Sc3N@C78 is studied by FTIR spectroscopy, Raman spectroscopy and DFT‐based quantum chemical calculations. Remarkably good agreement between experimental and calculated spectra is achieved and a full assignment of the Sc3N‐based vibrational modes is given. Significant differences in the vibrational structure of the endohedral cluster fullerene Sc3N@C78 and the empty, charged C786−: 5 (D3h′) are rationalized by the strong coupling between the Sc3N cluster and the fullerene cage. This coupling has its origin in a significant overlap of the Sc3N and C78 molecular orbitals, and causes atomic‐charge and bond‐length redistributions compared to the neutral C78 and the C786− anion. An ionic model is not sufficient to describe the electronic, geometric and vibrational structure of the Sc3N@C78 nitride cluster fullerene.
Nanoswitches Based on DNA Base Pairs: Why Adenin–Thymine is Less Suitable than Guanine–Cytosine
Authors: Fonseca Guerra Célia , van der Wijst Tushar , Bickelhaupt F. Matthias
Published: August 2006

Substituted Watson–Crick guanine–cytosine (GC) base pairs were recently shown to yield robust three‐state nanoswitches. Here, we address the question: Can such supramolecular switches also be based on Watson–Crick adenine‐thymine (AT) base pairs? We have theoretically analyzed AT pairs in which purine‐C8 and/or pyrimidine‐C6 positions carry a substituent X=NH−, NH2, NH3+(N series), O−, OH or OH2+(O series), using the generalized gradient approximation (GGA) of density functional theory at the BP86/TZ2P level. Thus, we explore the trend in geometrical shape and hydrogen bond strengths in AT pairs along a series of stepwise protonations of the substituents. Introducing a charge on the substituents leads to substantial and characteristic changes in the individual hydrogen bond lengths when compared to the neutral AT pair. However, the trends along the series of negative, neutral, and positive substituents are less systematic and less pronounced than for GC. In certain instances, internal proton transfer from thymine to adenine occurs. Our results suggest that AT is a less suitable candidate than GC in the quest for chemically controlled nanoswitches.
Self‐organized trail systems in groups of humans
Authors: Goldstone Robert L. , Roberts Michael E.
Published: August 2006

We have developed an experimental platform for studying the trail systems that spontaneously emerge when people are motivated to take advantage of the trails left by others. In this virtual environment, the participants' task is to reach randomly selected destinations while minimizing travel costs. The travel cost of every patch in the environment is inversely related to the number of times the patch was visited by others. The resulting trail systems are a compromise between people going to their destinations and going where many people have previously traveled. We compare the results from our group experiments to the Active Walker model of pedestrian motion from biophysics. The Active Walker model accounted for deviations of trails from the beeline paths, the gradual merging of trails over time, and the influences of scale and configuration of destinations on trail systems, as well as correctly predicting the approximate spatial distribution of people's steps. Two deviations of the model from empirically obtained results were corrected by (1) incorporating a distance metric sensitive to canonical horizontal and vertical axes, and (2) increasing the influence of a trail's travel cost on an agent's route as the agent approaches its destination. © 2006 Wiley Periodicals, Inc. Complexity 11: 43–50, 2006
Static and dynamic models of biological networks
Authors: Bhan Ashish , Mjolsness Eric
Published: August 2006

We consider static and dynamic approaches to the specification of probability distributions on graphs, consistent with desired statistical properties such as degree distributions, for use in modeling biological networks. In the static approach we develop analytical approximations to the Hamiltonian and partition functions. In the dynamic approach, we use a stochastic parameterized grammar to construct an evolutionary tree in which the nodes represent elements such as genes or cells and the links represent inheritance relations between the nodes. The grammar then constructs a network based on the feature vectors of the nodes in the tree. © 2006 Wiley Periodicals, Inc. Complexity 11:57–63, 2006
Quantitative linear unmixing of CFP and YFP from spectral images acquired with two‐photon excitation
Authors: Thaler Christopher , Vogel Steven S.
Published: August 2006

Background:

Spectrally distinct fluorescent proteins (FPs) have been developed permitting the visualization of several proteins simultaneously in living cells. The emission spectra of FPs, in most cases, overlap, making signal separation based on filter technology inefficient and in cases of bleed‐through, inaccurate. Spectral imaging can overcome these obstacles through a process called linear unmixing. Given a complex spectra composed of multiple fluorophores, linear unmixing can reduce the complex signal to its individual, weighted, component spectra. Spectral imaging with two‐photon excitation allows the collection of nontruncated emission spectra. The accuracy of linear unmixing under these conditions needs to be evaluated.

Methods:

Capillaries containing defined mixtures of CFP and YFP were used to test the accuracy of linear unmixing using spectral images obtained with two‐photon excitation.

Results:

Linear unmixing can be accurate when wavelength and power‐matched reference spectra are provided to the algorithm. Linear unmixing errors can occur due to (1) excitation laser contamination of emission signals, (2) the presence of FRET, (3) poor selection of excitation wavelength, and (4) failure to background subtract reference spectra.

Conclusions:

Linear unmixing, when judiciously performed, can accurately measure the abundance of CFP and YFP in mixed samples, even when their relative intensities range from 90:1. © 2006 International Society for Analytical Cytology
High intensity solid‐state UV source for time‐gated luminescence microscopy
Authors: Connally Russell , Jin Dayong , Piper James
Published: August 2006

Background.

The unique discriminative ability of immunofluorescent probes can be severely compromised when probe emission competes against naturally occurring, intrinsically fluorescent substances (autofluorophores). Luminescence microscopes that operate in the time‐domain can selectively resolve probes with long fluorescence lifetimes (τ > 100 μs) against short‐lived fluorescence to deliver greatly improved signal‐to‐noise ratio (SNR). A novel time‐gated luminescence microscope design is reported that employs an ultraviolet (UV) light emitting diode (LED) to excite fluorescence from a europium chelate immunoconjugate with a long fluorescence lifetime.

Methods.

A commercial Zeiss epifluorescence microscope was adapted for TGL operation by fitting with a time‐gated image‐intensified CCD camera and a high‐power (100 mW) UV LED. Capture of the luminescence was delayed for a precise interval following excitation so that autofluorescence was suppressed. Giardia cysts were labeled in situ with antibody conjugated to a europium chelate (BHHST) with a fluorescence lifetime >500 μs.

Results.

BHHST‐labeled Giardia cysts emit at 617 nm when excited in the UV and were difficult to locate within the matrix of fluorescent algae using conventional fluorescence microscopy, and the SNR of probe to autofluorescent background was 0.51:1. However in time‐gated luminescence mode with a gate‐delay of 5 μs, the SNR was improved to 12.8:1, a 25‐fold improvement.

Conclusion.

In comparison to xenon flashlamps, UV LEDs are inexpensive, easily powered, and extinguish quickly. Furthermore, the spiked emission of the LED enabled removal of spectral filters from the microscope to significantly improve efficiency of fluorescence excitation and capture. © 2006 International Society for Analytical Cytology
Flow cytometry controls, instrument setup, and the determination of positivity
Authors: Maecker Holden T. , Trotter Joseph
Published: August 2006

A frequent goal of flow cytometric analysis is to classify cells as positive or negative for a given marker, or to determine the precise ratio of positive to negative cells. This requires good and reproducible instrument setup, and careful use of controls for analyzing and interpreting the data. The type of controls to include in various kinds of flow cytometry experiments is a matter of some debate and discussion. In this tutorial, we classify controls in various categories, describe the options within each category, and discuss the merits of each option. © 2006 International Society for Analytical Cytology
The manifestation of infant hand‐use preferences when reaching for objects during the seven‐ to thirteen‐month age period
Authors: Michel George F. , Tyler Amber N. , Ferre Claudio , Sheu Ching‐Fan
Published: August 2006

Handedness is an aspect of hemispheric specialization whose pattern of expression may signal an unusual specialization that in turn, may underlie several developmental psychopathologies. It is generally believed that infant handedness is neither stable nor reliable and hence, cannot be used as an early marker of potential developmental abnormality of hemispheric specialization. We show that infant hand‐use preferences for apprehending objects can be reliably assessed and may be relatively stable throughout the 7–13 month age period. However, the results also demonstrate that identifying infant handedness requires assessment using very large sample sizes with multiple assessment periods because it is likely that there may be many more than three patterns in the development of handedness during infancy. © 2006 Wiley Periodicals, Inc. Dev Psychobiol 48: 436–443, 2006.
Plasticity in the development of handedness: Evidence from normal development and early asymmetric brain injury
Authors: Corbetta Daniela , Williams Joshua , Snapp‐Childs Winona
Published: August 2006

Previous research revealed that shifting patterns of hand preference in the first year of life are linked to infants' sensory‐motor experiences as they learn to sit, creep, and walk. In this report, we examine whether new and different forms of locomotion and sensory‐motor experiences similarly contribute to alter patterns of hand preference in early development. We examined the cases of three infants with unique developmental histories. Two infants adopted distinctive forms of locomotion in lieu of typical hands‐and‐knees crawling. One infant scooted using both hands and legs in a coupled fashion, while the other infant performed an asymmetrical, left‐biased belly‐crawl using only one arm to drag his body. The third infant suffered damage to his left‐brain hemisphere shortly after birth and received intense physical therapy to his right arm as a result of it. We followed all three infants on a weekly basis and tracked changes in their reaching behavior, mode of locomotion, and postural achievements. The two infants with unique locomotor patterns displayed changes in hand preference that reciprocated the arm patterns that they used during locomotion. The infant who coupled his body for scooting began to reach bimanually, while the infant who adopted the left‐biased belly‐crawl developed a strong unimanual, right‐hand, preference. The infant with left‐hemisphere damage initially displayed a right‐hand preference, then a temporary decline in preferred hand use as he began to cruise and walk, and ultimately resumed a right‐hand preference in the 2nd year of life. This data is consistent with previous work showing that the development of hand preference in the 1st year of life is highly malleable and sensitive to a variety of new sensory‐motor experiences. © 2006 Wiley Periodicals, Inc. Dev Psychobiol 48: 460–471, 2006.