bluuebunny/crossref_metadata_2025_split huggingface dataset:
Die Rolle der Chemokatalyse bei der Etablierung der Technologieplattform „Nachwachsende Rohstoffe”︁
Authors: Claus P. , Vogel G. H. 
Published: August 2006

AbstractDie 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

AbstractDie 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

AbstractZur 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

AbstractFestbettreaktoren 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

AbstractThe 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

AbstractSynthetic 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

AbstractAfter 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

AbstractBACKGROUND.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

AbstractThe 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

AbstractSubstituted 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

AbstractWe 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

AbstractWe 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

AbstractBackground: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

AbstractBackground.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

AbstractA 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

AbstractHandedness 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

AbstractPrevious 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.
Lateral preferences in children with intellectual deficiency of idiopathic origin
Authors: Leconte Pascale , Fagard Jacqueline 
Published: August 2006

AbstractThe goal of this study was to evaluate lateral preferences in a population of children with intellectual deficiency of idiopathic origin, compared with those of typically developing (TD) children. Two groups of children with mild or moderate intellectual deficiency were observed. Handedness (using a 10‐item test and Bishop's card‐reaching task), eyedness and footedness were studied. The younger group consisted of sixteen 10‐ to 11‐year olds; the older group comprised fourteen 12‐ to 14‐year olds. A control group of fifteen TD children was matched for age with the younger group of intellectually deficient (ID) children. The results show that the occurrence of left‐handedness is not higher in children with ID of unknown origin than in age‐matched TD children. However, we observed a marginally reduced tendency toward right‐handedness in ID than in TD children: more mixed‐handers among ID than TD children; test‐retest consistency of hand preference significantly lower in the 10‐ to 11‐year‐old ID children than in the age‐matched TD children; greater tendency of ID children to use their nonpreferred left hand when the card was presented to the left, as compared with TD children. Left‐eyedness and crossed hand‐eye preference were also more frequent in ID than in age‐matched TD children. No age‐related difference in laterality was found in ID children. These results partially support other studies indicating that less rightward asymmetry is associated with intellectual deficiency in children. © 2006 Wiley Periodicals, Inc. Dev Psychobiol 48: 492–500, 2006.
Product Diversity in the Reaction of [(norbornadiene){CpP(iPr)2}Rh] with Alkyl Iodides
Authors: Ortega Esteban , Kleigrewe Nina , Kehr Gerald , Erker Gerhard , Fröhlich Roland 
Published: August 2006

AbstractThe reagents [(CpPR2)Li] [R = iPr (2b), cyclohexyl (2c)] react with [(nbd)RhCl] (nbd = norbornadiene) dimer [(1a)2] to yield the respective mononuclear complexes [(nbd)Rh(CpPR2)] (3b,c). Subsequent treatment of 3b with a large excess of MeI led to the formation of the stable organometallic phosphonium salt [(nbd)Rh{CpP(iPr)2Me}]I (4b). The analogous reaction of 3b with the slightly more bulky EtI or nPrI resulted in the formation of the dinuclear [μ‐CpP(iPr)2]‐bridged dirhodium complex [(nbd)Rh{CpP(iPr)2}Rh(nbd)I] (5b) and the corresponding ylides C5H4P(iPr)2R1 [R1 = Et (6b), nPr (6c)]. The rhodium complexes 3b, 4a and 5b were characterised by X‐ray crystal‐structure analyses. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)