bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protein–Small Molecule Interactions in Neocarzinostatin, the Prototypical Enediyne Chromoprotein Antibiotic
Authors: Baker James R. , Woolfson Derek N. , Muskett Frederick W. , Stoneman Rhys G. , Urbaniak Michael D. , Caddick Stephen 
Published: April 2007

AbstractThe enediyne chromoproteins are a class of potent antitumour antibiotics comprising a 1:1 complex of a protein and a noncovalently bound chromophore. The protein is required to protect and transport the highly labile chromophore, which acts as the cytotoxic component by reacting with DNA leading to strand cleavage. A derivative of the best‐studied member of this class, neocarzinostatin (NCS), is currently in use as a chemotherapeutic in Japan. The application of the chromoproteins as therapeutics along with their unique mode of action has prompted widespread interest in this area. Notable developments include the discovery of non‐natural ligands for the apoproteins and the observation that multiple binding modes are available for these ligands in the binding site. Mutation studies on the apoproteins have revealed much about their stability and variability, and the application of an in vitro evolution method has conferred new binding specificity for unrelated ligands. These investigations hold great promise for the application of the apoproteins for drug‐delivery, transport and stabilisation systems.
Adsorption of SO2 on Activated Carbon for Low Gas Concentrations
Authors: Zhang P. , Wanko H. , Ulrich J. 
Published: April 2007

AbstractAdsorption experiments of SO2 on activated carbon has been carried out for low concentrations (about 100 ppm) at room temperature (15 to 33 °C) with varying humidity in the air. The breakthrough curves show that at high relative humidity or relative higher SO2 concentration, the load capacity increases with respect to temperature. The humidity of the air is also of benefit to the load capacity of SO2. When an adsorption process is interrupted and the activated carbon is kept closed for a while, the SO2 concentration at the exit of a fixed‐bed adsorber is similar to that of the fresh activated carbon and begins at a very low value. It appears that the sorption potential has been refreshed after the storage period. Analysis of desorption experiments by simultaneous thermal analysis combined with mass spectrometry (MS) after loading, shows that the physisorbed SO2 and H2O are desorbed at low temperatures. At higher temperatures, the MS peak of SO2 and H2O occur at the same time. Compared with desorption immediately after loading, after one day, the desorption peak due to the physisorbed SO2 disappears. From this, it can be concluded that the refreshment of the loading capacity of the activated carbon after storage is mainly due to a change in the nature of the SO2 from a physisorbed state to a chemisorbed form. The same mechanism leads to a continuous refreshment of the sorption potential by means of a chemical reaction during the adsorption process.
Creeping Film Models for Rotating Channels
Authors: Mondt E. , Brouwers B. , van Kemenade E. 
Published: April 2007

AbstractA theoretical analysis is presented for the development of a liquid film at the walls of vertically placed centrifugal separators. The liquid film arises at the walls of these separators due to the action of the centrifugal force on the entrained liquid phases. The analysis applies to situations, for which the liquid load is small, i.e., the film thickness is much smaller than the height of the channel. This implies that the film can be regarded as a laminar boundary‐layer type flow with negligible inertia effects. Solutions are presented for situations in which the liquid droplets flow co‐currently and counter‐currently with the gas flow.
Using CFD and Ultrasonic velocimetry to Study the Mixing of Pseudoplastic Fluids with a Helical Ribbon Impeller
Authors: Ihejirika I. , Ein‐Mozaffari F. 
Published: April 2007

AbstractA commercial CFD package was used to simulate the 3D flow field generated in a cylindrical tank by a helical ribbon impeller. The study was carried out using a pseudoplastic fluid with yield stress in the laminar mixing region. Ultrasonic Doppler velocimetry (UDV), a noninvasive fluid flow measurement technique for opaque systems, was used to measure xanthan gum velocity. From flow field calculations and tracer homogenization simulations, power consumption and mixing time results were obtained. The torque and power characteristics remain the same for upward and downward pumping of the impeller, but the mixing times are considerably longer for the downward pumping mode. Overall, the numerical results showed good agreement with experimental results and correlations developed by other researchers. From the power and mixing time results, two efficiency criteria were utilized to determine the best pumping mode of the impeller.
Effect of CaSO4 Pelletization Conditions on a Novel Process for Converting SO2 to Elemental Sulfur by Reaction Cycles involving CaSO4/CaS – Part I. CaSO4 Pellet Strength and Reducibility by Hydrogen
Authors: Eob Choi M. , Sohn H. Y. , Ahmed Y. M. Z. , Mohamed F. M. , Han G. , Shalabi M. E. H. 
Published: April 2007

AbstractA new process for converting sulfur dioxide to elemental sulfur by reaction cycles involving calcium sulfide and calcium sulfate without generating secondary pollutants was developed at the University of Utah. In this process, sulfur dioxide is reacted with calcium sulfide to produce elemental sulfur and calcium sulfate. The latter is reduced by hydrogen to regenerate calcium sulfide. In the present work, the effects of different pelletization conditions for the initial reactant calcium sulfate on the strength and reactivity of the pellets were determined. These pelletization conditions included the type, amount, and impregnation method of catalyst, the binder amount, and sintering. The pellets with the best properties were then reduced with hydrogen in the temperature range 973 to 1173 K, while measuring the kinetics, over several cycles of the two‐step process. Nickel‐catalyzed and fired pellets produced by the use of molasses or cement as a binder showed the highest compressive strength as well as good reactivity during the cyclic tests. The binder amount did not significantly affect the reaction rate.
Die Chemische Reaktion im Chemieanfangsunterricht. Eine experimentelle Erarbeitung am Beispiel der Verbrennung
Authors: Heimann Rebekka , Harsch Günther 
Published: April 2007

AbstractZahlreiche Untersuchungen haben gezeigt, dass Schülerinnen und Schüler verschiedener Jahrgangsstufen erhebliche Probleme mit dem Verständnis grundlegender chemischer Begriffe aufweisen und trotz schulischer Instruktion an ihren ursprünglichen Vorstellungen festhalten (z.B. [1]). Dies gilt auch für den Begriff der chemischen Reaktion [z.B. 2‐5]. Der Einführung der chemischen Reaktion sollte also ein besonderes Augenmerk gelten. Man findet in der Literatur viele Vorschläge hierzu (z.B. [6‐9]). Was also ist das Charakteristische an diesem Beitrag? Unsere Einführung in die chemische Reaktion ist durch die folgenden Merkmale gekennzeichnet:

Konkret vernetzte Erarbeitung der verschiedenen Aspekte der chemischen Reaktion
Interpretation chemischer Reaktionen konsequent und von Anfang an mit dem Dalton‐Modell
Hilfe bei der Begriffsbildung durch systematisches Prüfen von Vorstellungen mit Hilfe von Experimenten, was gleichzeitig die Kompetenzentwicklung im Bereich der Erkenntnisgewinnung fördern soll
Wiederholte Anwendung des so erarbeiteten Begriffs in einem vernetzten Zusammenhang.
Diese Punkte sollen kurz erläutert werden. Grundlegende Aspekte des Begriffs der chemischen Reaktion sind die folgenden:

Entstehung komplett neuer Stoffe mit einer neuen Eigenschaftskombination;
Die prinzipielle Möglichkeit der Rückgewinnung der Edukte, also keine unwiederbringliche Zerstörung von Stoffen;
Die Erhaltung der Masse bei der Stoffumwandlung. Hinzu kommen energetische Veränderungen.
Chemie‐Edutainment auf dem Prüfstand: Evaluierung der „Zaubervorlesung mit Salvador Dalí”︁
Authors: Schiessl Wolfgang , Pfeifer Peter , van Eldik Rudi 
Published: April 2007

AbstractChemie ist kein beliebtes Fach. Befragungen unter Schülern gehen bis ins Jahr 1905 zurück und zeichnen ein einheitliches Bild [1]. Die mangelnde Popularität dieses Faches beschränkt sich jedoch nicht auf Schüler. Das Image der Chemie lässt in der gesamten Öffentlichkeit zu wünschen übrig. Allzu leicht bezieht man sich hier ausschließlich auf Chemie‐Unfälle und negative Schlagzeilen. Es fehlt am Verständnis, inwieweit chemische Grundlagen jeden Bereich unseres täglichen Lebens durchdringen, von Atemluft über Lebensprozesse bis zu Zahnpasta. Tatsächlich gilt: „Chemie ist unser Leben!”︁ [2]. Um hier Umdenken zu bewirken, stehen wir in der Verantwortung, vor allem Wissen um Chemie im Alltag zu vermitteln, sowohl Schülern, als auch der Öffentlichkeit. Angesichts der generell eher ablehnenden Haltung, ist dies jedoch kein leichtes Unterfangen. Gilt es doch als gesichert, dass Lernzuwachs wesentlich von der affektiven Haltung dem Inhalt gegenüber abhängt [3]. Edutainment verspricht hier einen interessanten Ansatz – unterhaltend und (quasi nebenbei) lehrreich zu sein. Der Begriff setzt sich zusammen aus „education”︁ und „entertainment”︁ und versucht eine Symbiose beider. Lehransätze dieser Art reichen mittlerweile von Lernsoftware bis zu aktuellen Fernsehsendungen, die Unterhaltung und Wissenstransfer zur besten Sendezeit kombinieren. Doch ist dies auch in einer abendfüllenden Veranstaltung live möglich?
Late occurrence of malignant post‐transplant lymphoproliferative disorder (PTLD) presenting with severe acute renal failure
Authors: Ziari Mohammadbagher , Kudva Ganesh C. , Salinas‐Madrigal Luis , Cortese Cherise , Garvin Paul , Osman Medhat M. , Bastani Bahar 
Published: April 2007

AbstractWe report the case of a 63‐year‐old man who presented with severe acute renal failure requiring dialysis 17 years after a successful renal transplant of a kidney from his daughter. Transplant kidney biopsy revealed post‐transplant lymphoproliferative disorder‐large B‐cell lymphoma. A PET scan revealed widespread disease, particularly involving the transplanted kidney. The patient responded rapidly to chemotherapy with VACOP‐B and rituximab, with a complete resolution of renal failure and of the findings from the PET scan. The patient was in remission for 6 months, while on chemotherapy, before he was found to have recurrence of the disease in cervical lymph nodes and died 1 month later with normal kidney function.
Characterization of astrocyte‐specific conditional knockouts
Authors: Casper Kristen B. , Jones Kristin , McCarthy Ken D. 
Published: April 2007

AbstractConditional gene knockouts are a very powerful tool for elucidating gene function in animal physiology and behavior. To obtain cell‐specific knockouts, a promoter is utilized that drives expression of Cre recombinase specifically to the cell population of interest. We describe several transgenic lines of mice that were created in an attempt to obtain astrocyte‐specific gene recombination. A 2 kb fragment from the human glial fibrillary acidic protein promoter is utilized to drive expression of inducible Cre recombinase, with both the Tet‐Off and tamoxifen responsive systems. We show data obtained from crosses with two Cre reporter lines, ROSA26R and an astrocyte Cre reporter created in our laboratory, to assess the cell specificity of gene recombination. Additionally, our system is shown to successfully recombine a floxed Connexin43 locus, although recombination is not as extensive as seen in crosses with reporter lines. genesis 45:292–299, 2007. © 2007 Wiley‐Liss, Inc.
NMR Studies of Paramagnetic Metallocarbaporphyrinoids
Authors: Pacholska‐Dudziak Ewa , Latos‐Grażyński Lechosław 
Published: April 2007

AbstractCarbaporphyrinoids provide a suitable macrocyclic platform for organometallic investigations that provide unique opportunities for modifying a macrocyclic structure. Alteration of a coordination core is a route of choice for stabilizing unusual metal ion oxidation states and coordination geometries. This microreview presents the general characteristic of paramagnetic metallocarbaporphyrinoids, with a focus on NMR studies. NMR spectroscopy of paramagnetic molecules can be considered as a powerful probe of several intriguing aspects of the molecular and electronic structures, structural rearrangements, and reactivity, including oxidation and oxygenation, of this fascinating class of compounds. The chosen examples address paramagnetic organometallic nickel(II) and nickel(III) complexes of N‐confused porphyrins, the reactions of nickel(II) dimethylated N‐confused porphyrins with organometallic reagents, the stabilization of rare organocopper(II) species, the investigation of weak intramolecular metal–arene interactions, and the conformational flexibility of nickel(II) benziporphyrin and vacataporphyrin. Particular emphasis is placed on NMR studies as an efficient way of detecting intermediate species formed in the course of oxidation and oxygenation of iron(n) carbaporphyrinoids. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Oxidative Desulfurization of Azole‐2‐thiones with Benzoyl Peroxide: Syntheses of Ionic Liquids and Other Azolium Salts
Authors: Wolfe Derek M. , Schreiner Peter R. 
Published: April 2007

Abstract1‐Alkyl‐3‐methylimidazole‐2‐thiones were prepared from amino esters in one pot and converted to inherently halide‐free 1‐alkyl‐3‐methylimidazolium benzoates by oxidation with benzoyl peroxide followed by a novel anion exchange. Also reported are the outcomes of exchanges with other anions, acidifications of the imidazolium benzoates to other salts, and extension of the method to the syntheses of 1,3‐diphenylimidazolium and 3‐methyl‐ and ‐butylthiazolium salts.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Why we're still arguing about the Pleistocene occupation of the Americas
Authors: Waguespack Nicole M. 
Published: April 2007

AbstractAlthough empirical issues surround the when, how, and who questions of New World colonization, much of current debate hinges on theoretical problems because it has become clear that our understanding of New World colonization is not resolute.1 In fact, the central issues of debate have remained essentially unchanged for the last eighty years. The now classic and probably incorrect story of New World colonization begins in Late Pleistocene Siberia, with small a population of foragers migrating across Beringia (∼13,500 calendar years before present (CYBP) (Box 1) through an ice‐free corridor and traveling through the interior of North America. High mobility and rapid population growth spurred southward expansion into increasingly distant unoccupied regions, culminating in the settlement of the Southern Cone of South America. Armed with the skills and weapons needed to maintain a megafauna‐based subsistence strategy, early colonists necessarily had the adaptive flexibility to colonize a diverse array of Pleistocene landscapes. For a time, this scenario seemed well substantiated. The earliest sites in South America were younger than their northern counterparts, fluted artifacts were found across the Americas within a brief temporal window, and projectile points capable of wounding elephant‐sized prey were commonly found in association with proboscidean remains. The Bering Land Bridge connecting Asia to Alaska and an ice‐free corridor providing passage between the Pleistocene ice masses of Canada seemed to provide a clear route of entry for Clovis colonists. However, recent archeological, paleoenvironmental, biological, and theoretical work largely questions the plausibility of these events.
The Evolution of Zinjanthropus boisei
Authors: Constantino Paul , Wood Bernard 
Published: April 2007

AbstractMany people assume that OH 5, the type specimen of Paranthropus boisei, collected in 1959, was the first evidence of that taxon to be found, but OH 3, recovered in 1955, predated the discovery of OH 5 by four years. Thus, Paranthropus boisei recently celebrated the equivalent of its fiftieth birthday. This review marks that milestone by examining the way our understanding of this taxon has changed during its fifty, or so, year history.
Coupled ghost fluid/two‐phase level set method for curvilinear body‐fitted grids
Authors: Huang Juntao , Carrica Pablo M. , Stern Frederick 
Published: April 2007

AbstractA coupled ghost fluid/two‐phase level set method to simulate air/water turbulent flow for complex geometries using curvilinear body‐fitted grids is presented. The proposed method is intended to treat ship hydrodynamics problems. The original level set method for moving interface flows was based on Heaviside functions to smooth all fluid properties across the interface. We call this the Heaviside function method (HFM). The HFM requires fine grids across the interface. The ghost fluid method (GFM) has been designed to explicitly enforce the interfacial jump conditions, but the implementation of the jump conditions in curvilinear grids is intricate. To overcome these difficulties a coupled GFM/HFM method was developed in which approximate jump conditions are derived for piezometric pressure and velocity and pressure gradients based on exact continuous velocity and stress and jump in momentum conditions with the jump in density maintained
but continuity of the molecular and turbulent viscosities imposed. The implementation of the ghost points is such that no duplication of memory storage is necessary. The level set method is adopted to locate the air/water interface, and a fast marching method was implemented in curvilinear grids to reinitialize the level set function. Validations are performed for three tests: super‐ and sub‐critical flow without wave breaking and an impulsive plunging wave breaking over 2D submerged bumps, and the flow around surface combatant model DTMB 5512. Comparisons are made against experimental data, HFM and single‐phase level set computations. The proposed method performed very well and shows great potential to treat complicated turbulent flows related to ship flows. Copyright © 2007 John Wiley & Sons, Ltd.
Direct simulation of two‐dimensional turbulent flow over a surface‐mounted obstacle
Authors: Fragos V. P. , Psychoudaki S. P. , Malamataris N. A. 
Published: April 2007

AbstractTwo‐dimensional turbulent flow over a surface‐mounted obstacle is studied as a numerical experiment that takes place in a wind tunnel. The transient Navier–Stokes equations are solved directly with Galerkin finite elements. The Reynolds number defined with respect to the height of the wind tunnel is 12 518. Instantaneous streamline patterns are shown that give a complete picture of the flow phenomena. Energy and enstrophy spectra yield the dual cascade of two‐dimensional turbulence and the −1 power law decay of enstrophy. Mean values of velocities and root mean square fluctuations are compared with the available experimental results. Other statistical characteristics of turbulence such as Eulerian autocorrelation coefficients, longitudinal and lateral coefficients are also computed. Finally, oscillation diagrams of computed velocity fluctuations yield the chaotic behaviour of turbulence. Copyright © 2007 John Wiley & Sons, Ltd.
Effects of combined intervention programmes for people with dementia living at home and their caregivers: a systematic review
Authors: Smits Carolien H. M. , de Lange Jacomine , Dröes Rose‐Marie , Meiland Franka , Vernooij‐Dassen Myrra , Pot Anne Margriet 
Published: April 2007

AbstractObjectiveThis study reviews the evidence for effects of combined intervention programmes for both the informal caregiver and the person with dementia.MethodSystematic review. Electronic databases and key articles were searched for effect studies of combined programmes, published between January 1992 and February 2005. The resulting 52 reports were scored according to set inclusion criteria.ResultsTwenty five reports relating to 22 programmes met the inclusion criteria. Various aspects of caregivers' mental health and burden were studied. Best results were obtained regarding general mental health. Other aspects often showed modest and varying results. Caregivers' competence was less often addressed. The effects on the cognitive and physical functioning, behavioural problems and survival of the persons with dementia were modest and inconsistent, whereas their mental health is positively affected and admittance to long stay care is often delayed.ConclusionCombined programmes may improve some, not all, aspects of functioning for caregiver and person with dementia. Care professionals must define their programme goals and target groups before advising their clients on a combined programme. Research may focus on the effects of programmes that were introduced fairly recently and on subgroups of caregivers (female caregivers, depressed caregivers and people with dementia, and minorities). Copyright © 2007 John Wiley & Sons, Ltd.
Neural basis of processing sequential and hierarchical syntactic structures
Authors: Opitz Bertram , Friederici Angela D. 
Published: April 2007

AbstractThe psychological processes through which humans learn a language have gained considerable interest over the past years. It has been previously suggested that language acquisition partly relies on a rule‐based mechanism that is mediated by the frontal cortex. Interestingly, the actual structure involved within the frontal cortex varies with the kind of rules being processed. By means of functional MRI we investigated the neural underpinnings of rule‐based language processing using an artificial language that allows direct comparisons between local phrase structure dependencies and hierarchically structured long‐distance dependencies. Activation in the left ventral premotor cortex (PMC) was related to the local character of rule change, whereas long‐distance dependencies activated the opercular part of the inferior frontal gyrus (Broca's area (BA) 44). These results suggest that the brain's involvement in syntactic processing is determined by the type of rule used, with BA 44/45 playing an important role during language processing when long‐distance dependencies are processed. In contrast, the ventral PMC seems to subserve the processing of local dependencies. In addition, hippocampal activity was observed for local dependencies, indicating that the processing of such dependencies may be mediated by a second mechanism. Hum Brain Mapp, 2007. © 2007 Wiley‐Liss, Inc.
Role of dCA3 efferents via the fimbria in the acquisition of a delay nonmatch to place task
Authors: Hunsaker Michael R. , Allan Kimberly D. , Kesner Raymond P. 
Published: April 2007

AbstractDorsal CA3, but not dorsal CA1, lesioned rats are impaired in the acquisition of a delay nonmatch to place task. In this study, dorsal CA3 efferent fibers in the fimbria were transected; while taking care to spare afferent fibers from the medial septum. Neurophysiological, anatomical tracing, and histochemical data suggest that the transection was selective to dorsal CA3 efferent fibers and spared afferents from the medial septum. Rats showed a deficit for acquisition, but not for performance once learned. One possible explanation is that a small change to the cholinergic inputs to dCA3 caused by a decrease in dorsal CA3 efferent signals reaching the medial septum may impair new learning but not performance of a task once learned. © 2007 Wiley‐Liss, Inc.