bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of deuteriomethyl aromatic hydrocarbons by exchange with dimethylsulfoxide‐d6
Authors: Chen T.‐S. , Wolinska‐Mocydlarz J. , Leitch L. C. 
Published: October 2006

AbstractDeuterium exchange between dimethylsulfoxide‐D6 (DMSO‐D6) and methyl substituted aromatic hydrocarbons such as toluene, the xylenes, mesitylene, methylnaphthalenes and methylphenanthrenes is a convenient general method of preparing the CD3 analogues.
Peptide and protein labelling with iodine, iodine monochloride reaction with aqueous solution of L‐tyrosine, L‐histidine, L‐histidine‐peptides, and his effect on some simple disulfide bridges
Authors: Hung Lam Thanh , Fermandjian S. , Morgat J. L. , Fromageot P. 
Published: October 2006

AbstractIodinated peptides or proteins (125I, 131I) are used as tracers for radioimmono assays and for detection in biological systems. The labelling takes place on the aromatic side chains.However, when disulfide bridges are present, iodination must be carried out under conditions preventing their degradation. The rate of iodination of L‐tyrosine, L‐histidine and L‐histidine containing peptides by iodine monochloride (ICI) are studied by spectroscopy. Free hitidine increases the hydrolysis rate of aqueous solution of ICI. The interactions between ICI and some simple disulfide are investigated by circular dichroism measurements. These reactions are presented as models for degradation of disulfide bridges in peptide or protein during the iodination process.
Labeled steroids of potential biological interest: Synthesis and properties of 180‐labeled 17 α‐hydroperoxypro‐gesterone
Authors: Falardeau Pierre , Tan Liat 
Published: October 2006

Abstract18Oxygen labeled 17α‐hydroperoxyprogesterone has been synthesized via a 3‐step reaction sequence in an all‐glass, high vacuum transfer system. The hydroperoxidation reaction was found to proceed smoothly only, when an adequate oxygen pressure in the reaction vessel is maintained. Comparisons are made between the mass spectral fragmentations of the ordinary 16O, and the isotopically labeled 180–17α‐hydroperoxyprogesterones. Their NMR‐spectra display a splitting of the 18‐, and 31‐methyl signals, probably due to the coexistence of two finite conformations of the acetyl side‐chain.
Application of liquid chromatography/quadrupole time‐of‐flight mass spectrometry (LC‐QqTOF‐MS) in the environmental analysis
Authors: Petrovic M. , Barceló D. 
Published: October 2006

AbstractThis paper gives an overview of the potentials of liquid chromatography‐hybrid quadrupole time‐of‐flight mass spectrometry (LC‐QqTOF) in the environmental analysis. Examples of applications of QqTOF instruments for target analysis of pharmaceuticals and pesticides are presented and discussed, as well as applications aimed on the identification of unknown compounds present in environmental waters or on the elucidation of structures of biodegradation and photodegradation products. Specific issues such as uncertainty of mass measurement and quantitative performances are discussed in details. Copyright © 2006 John Wiley & Sons, Ltd.
Battles and beliefs rethinking the roles of today's leaders
Authors: Bolman Lee G. , Deal Terrence E. 
Published: October 2006

AbstractThe modern business environment is wild, messy, and unpredictable. That's why the two operating frameworks that leaders have typically relied on—the caregiver and the analyst—are no longer enough. Two additional frameworks—the wizard and the warrior—can help leaders make sense of the political and symbolic predicaments that organizations face daily.
Vinyl Polymers as Non‐Viral Gene Delivery Carriers: Current Status and Prospects
Authors: Dubruel Peter , Schacht Etienne 
Published: October 2006

AbstractSummary:Since the first application of polymers as non‐viral gene delivery systems in 1965 by Vaheri and Pagano using functionalised dextran (A. Vaheri and J. S. Pagano, “Infectious poliovirus RNA: a sensitive method of assay”,Virology1965,27, 434–6), a large number of different polymers have been developed, studied and compared for application as DNA carriers. Vinyl‐based polymers are one type of polymers that have gained considerable interest. The interest in developing this particular type of polymer is partly related to the straightforward way in which large amounts of these polymers can be prepared by radical (co)polymerisation. This opens up a path for establishing a wide range of structure‐property relations using polymer libraries. The present review aims to give an overview of past and ongoing research using vinyl‐based gene delivery systems. The application of cationic, neutral and zwitterionic polymers as DNA carriers is summarised and discussed.Chemical structure of DEAE‐functionalised dextran.magnified imageChemical structure of DEAE‐functionalised dextran.
Photocatalytic Deposition of Silver Nanoparticles onto Organic/Inorganic Composite Nanofibers
Authors: Lim Sang Kyoo , Lee Soo‐Keun , Hwang Sung‐Ho , Kim Hoyoung 
Published: October 2006

AbstractSummary: In this work, silver nanoparticles were embedded in electrospun organic/inorganic composite nanofibers consisting of PAN and TiO2 through photocatalytic reduction of the silver ions in silver nitrate solutions under UV irradiation. The morphology and diameter of PAN/TiO2 composite nanofibers could be controlled by varying the initial contents of TiO2 in the spinning solution. From TEM images and UV‐Vis spectra, it has been confirmed that monodisperse silver nanoparticles with a diameter of ≈2 nm were deposited selectively upon the titania of the as prepared composite nanofibers. The amount of Ag nanoparticles embedded on composite nanofibers was greatly influenced by the amount of TiO2 in composite nanofibers, reflecting the role of titania as the inorganic stabilizer and photocatalyst.Morphology of silver nanoparticles embedded on PAN/TiO2 composite nanofibers.magnified imageMorphology of silver nanoparticles embedded on PAN/TiO2 composite nanofibers.
Donor cell differentiation, reprogramming, and cloning efficiency: Elusive or illusive correlation?
Authors: Oback B. , Wells D.N. 
Published: October 2006

AbstractCompared to other assisted reproductive technologies, mammalian nuclear transfer (NT) cloning is inefficient in generating viable offspring. It has been postulated that nuclear reprogramming and cloning efficiency can be increased by choosing less differentiated cell types as nuclear donors. This hypothesis is mainly supported by comparative mouse cloning experiments using early blastomeres, embryonic stem (ES) cells, and terminally differentiated somatic donor cells. We have re‐evaluated these comparisons, taking into account different NT procedures, the use of donor cells from different genetic backgrounds, sex, cell cycle stages, and the lack of robust statistical significance when post‐blastocyst development is compared. We argue that while the reprogrammability of early blastomeres appears to be much higher than that of somatic cells, it has so far not been conclusively determined whether differentiation status affects cloning efficiency within somatic donor cell lineages. Mol. Reprod. Dev. 74: 646–654, 2007. © 2006 Wiley‐Liss, Inc.
Advanced three‐dimensional tailored RF pulse for signal recovery in T2*‐weighted functional magnetic resonance imaging
Authors: Yip Chun‐yu , Fessler Jeffrey A. , Noll Douglas C. 
Published: October 2006

AbstractT‐weighted functional MR images are plagued by signal loss artifacts caused by susceptibility‐induced through‐plane dephasing. We present major advances to the original three‐dimensional tailored RF (3DTRF) pulse method that pre‐compensates the dephasing using three‐dimensional selective excitation. The proposed 3DTRF pulses are designed iteratively with off‐resonance incorporation and with a novel echo‐volumar trajectory that frequency‐encodes in z and phase‐encodes in x,y. We also propose a computational scheme to accelerate the pulse design process. We demonstrate effective signal recovery in a 5‐mm slice in both phantom and inferior brain, using 3DTRF pulses that are only 15.4 ms long. Compared to the original method, the new approach leads to significantly reduced pulse length and enhancement in slice selectivity. 3D images of the slice volume confirm fidelity of the excited phase pattern and slice profile. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Das Phänomen des zweiten Boten
Authors: Moll Friedrich 
Published: October 2006

AbstractUm mit einem Minimum an hochspezifischem Signalträger auszukommen, hat die Natur den raffinierten second‐messenger‐Mechanismus erdacht. Ein first messenger, hier Adrenalin, schickt tausend second messengers auf den Weg, damit sie Glycogen zu Glucose‐1‐phosphat mobilisieren.
BGA will Codein verbieten
Authors: Grimm Gorm , Pachaly P. 
Published: October 2006

AbstractOpiophobe Arroganz einer Behörde?Trotz zahlreicher überzeugender Erfolge bei der Substitutionstherapie Drogenabhängiger scheint das Bundesgesundheitsamt an seiner behördlichen Opiophobie festzuhalten, – oder ist es nur behördliche Arroganz (?), die anscheinend verhindern will, daß hoffnungslos Süchtigen (= kranken Menschen) wenigstens soweit geholfen werden kann, daß diese Ärmsten unserer Gesellschaft eine Chance haben, sich in die soziale Gemeinschaft wieder einfügen können. Müssen denn weiterhin Verbrechen, Erpressung, Prostitution und totale Verelendung die unvermeidlichen Meilensteine bis zum tödlichen „Goldenen Schuß”︁ auf der Bahnhofstoilette sein, die nicht nur den Betroffenen, sondern auch den beteiligten Familien unendliches Leid zumuten? Anbetracht der offensichtlichen Erfolge, die man z. B. in England sogar mit der kontrollierten Hereingabe an abhängige Patienten gemacht hat, erscheint die kürzlich erfolgte Ablehnung eines entsprechenden Antrags der Stadt Frankfurt durch das BGA vollends unverständlich. Geradezu zynisch wirkt die BGA‐Begründung: „Es macht doch keinen Sinn, Süchtige durch Suchtmittel von ihrer Sucht zu befreien”︁. Anscheinend hat man völlig vergessen, daß auch diese Kranken einen Anspruch wenigstens auf eine symptomatische Behandlung haben – auch wenn das Mittel die Ursache nicht bekämpfen kann. Die Meinungsäußerung des wahrlich betroffenen und verantwortungsbereiten Mediziners Dr. med. Gorm Grimm, der sich seit Jahren dieser Problematik stellt und zu helfen versucht, macht diesen Problemkreis noch einmal deutlich.
Die Küchenzwiebel – eine zu Unrecht vernachlässigte Arzneipflanze
Authors: Koch Heinrich P. 
Published: October 2006

AbstractDie gemeine Küchenzwiebel, unverzichtbar in unserer Eßkultur und uralter Bestandteil traditioneller Medizin, erweist sich auch nach neuesten Untersuchungen als hochwertige Arzneipflanze, zu deren wichtigsten Wirkstoffen offenbar nicht die geruchsaktiven Schwefelverbindungen, sondern Steroid‐ und Triterpensaponine mit antimikrobiellen, kardiovaskulären, z. B. antiaggregatorischen, fibrinolytischen und hypolipidämischen Effekten zählen. Über die Inhaltsstoffe der Zwiebel, ihre Wirkungen und ihre Anwendungen wird in diesem Aufsatz berichtet.
Role of anions in the polymerization of 2,5‐dimethoxyaniline in the presence of poly(styrene sulfonic acid)
Authors: Huang Li‐Ming , Huang Guo Cheng , Wen Ten‐Chin 
Published: October 2006

AbstractPoly(2,5‐dimethoxyaniline) (PDMA)–Ag composites were successfully obtained through the oxidative polymerization of 2,5‐dimethoxyaniline in poly(styrene sulfonic acid) with CH3SO3Ag and AgNO3 as oxidants. In situ ultraviolet–visible spectroscopy results showed that the growth rate of PDMA was strongly affected by CH3SO and NO. The coupling reaction of PDMA and NO was proposed to explain the lower growth rate of PDMA with AgNO3 as the oxidant in comparison with CH3SO3Ag. X‐ray photoelectron spectroscopy and Fourier transform infrared spectroscopy were used to validate the proposed coupling reaction through the monitoring of the side products and oxidized state of PDMA. The results showed that there were more side products and lower oxidized states for the composite structure in the presence of NO than in the presence of CH3SO, and this agreed with the proposal. Transmission electron microscopy showed that the Ag nanoparticles had almost the same size, regardless of the anions. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6624–6632, 2006
The Effect of Cook‐Off on the Bulk Permeability of a Plastic Bonded Explosive
Authors: Terrones Guillermo , Souto Francisco J. , Burkett Michael W. , Shea Robert F. , Idar Edward S. 
Published: October 2006

AbstractPlastic bonded explosives when exposed to prolonged heating environments undergo a variety of changes that affect their bulk chemical, thermophysical, and mechanical properties. During slow heating conditions, referred to as cook‐off, the thermal behavior of the polymeric binder plays an important role in the transformations of these composite energetic materials. The recently introduced Darcian flow hypothesis for PBX‐9501 implies that, during preignition, temperature gradients will lead to pressure gradients which in turn will drive convection of decomposition gases throughout the explosive, thus affecting ignition time and location. Here, we focus on the cook‐off behavior of PBX‐9501 and investigate its effects on bulk permeability to gases produced as a result of thermal decomposition. The concept of Darcian convection through porous media is defined and illustrated in detail by the derivation of the governing equations for a permeameter. Based on a systematic analysis involving: 1) our current understanding about binder behavior as a function of temperature, 2) the physics of the gas permeameter apparatus, 3) the concept of liquid drainage by gas, and 4) the experimental record of four permeameter experiments with cooked PBX‐9501, we conclude that samples heated up to 186 °C were not permeable in the Darcy‐flow sense.
A new dissipativity criterion—towards Yakubovich oscillations
Authors: Răsvan Vl. 
Published: October 2006

AbstractStarting from the idea that two pre‐requisites are required to obtain existence criteria for Yakubovich oscillations (bounded state trajectory plus an output changing sign infinitely), namely instability or at least some dichotomic behaviour and Levinson dissipativity (ultimate boundedness), the paper focuses on the latter subject: its main result is the extension to dissipativity of a frequency domain inequality that makes use of only slope information concerning the nonlinear functions. Several examples are discussed and final conclusions are drawn concerning future developments. Copyright © 2006 John Wiley & Sons, Ltd.
On theory of learning and knowledge: Educational implications of advances in neuroscience
Authors: Hendry Graham D. , King Ronald C. 
Published: October 2006

AbstractThe first section analyses the so‐called mechanical theories of learning that underpin the transmission view of teaching that so permeates education and schooling. There is an impasse in current theories due to lack of explanation about how we acquire knowledge. In response to what appears to be insuperable problems in current psychological theories, the second section promotes a neuroscientific basis for resolution of the impasse; a basis which renders at least some aspects of information theory redundant. Finally, implications for the transmission‐of‐knowledge approach to teaching are addressed. © 1994 John Wiley & Sons, Inc.
Reexamining connections: Museums as science learning environments
Authors: Ramey‐Gassert Linda , Walberg Herbert J. , Walberg Herbert J. 
Published: October 2006

AbstractThe role of science museums in science education is changing. This article examines the science museum literature in light of the new emphasis for museums to become a unique partner with schools and colleges to enhance science literacy. Museums provide opportunities for students to be active participants in learning by manipulating real objects in a stimulating setting thus enhancing conceptual learning in the classroom. Both components of learning are important for understanding of complex science concepts. Much of the literature pertaining to learning in museums is anecdotal and craft wisdom, indicating that more collaborative research efforts are needed in the area of science education in museum settings. © 1994 John Wiley & Sons, Inc.
Does the use of analogies contribute to conceptual change?
Authors: Dagher Zoubeida R. 
Published: October 2006

AbstractThe nature of the contribution of analogies to conceptual change is far from straight forward. First, review of three studies and evidence from other sources point to a modest contribution of analogies to normal conceptual change. Second, the construct of conceptual change has been defined in many ways with more preeminence given to radical conceptual change. I point out that weak or normal conceptual change is worthy of equal attention from science educators. Third, conceptualizing conceptual change in terms of gradations on a continuum enables teachers and researchers to achieve a clearer understanding of the way in which analogies contribute to conceptual change. Fourth, in order to give analogies a fair evaluation, the conceptual change paradigm ought to endorse a broader conception of change which conjoins propositional and procedural knowledge and accounts for the affective and creative processes that are associated with the education of the whole person and not only the learning of specific concepts. © 1994 John Wiley & Sons, Inc.
Science and students with mental retardation: An analysis of curriculum features and learner characteristics
Authors: Scruggs Thomas E. , Mastropieri Margo A. 
Published: October 2006

AbstractAlthough much research has been conducted on the learning characteristics of individuals with mental retardation, science learning of such individuals has received far less attention. In this investigation, students with mental retardation were observed over a 2‐year period, in order to determine how the characteristics of mental retardation manifested themselves in the context of inquiry‐oriented, hands‐on science curriculum. Analysis of all relevant data sources, including observations and field notes, videotape and audiotape recordings, student products, and interviews, suggested that several characteristics commonly attributed to students with mild mental retardation were observed to interact with the science curriculum. These characteristics included attention, semantic memory, logical reasoning, and outerdirectedness. However, teachers were skilled at adapting instruction to meet the special needs of these learners. Implications for teaching science to students with mental retardation are provided. © 1995 John Wiley & Sons, Inc.
The relationship between exhibit characteristics and learning‐associated behaviors in a science museum discovery space
Authors: Boisvert Dorothy Lozowski , Slez Brenda Jochums 
Published: October 2006

AbstractResearchers and evaluators have often used observation of visitor behavior as an indirect assessment of the educational impact of museum exhibits. The educational impact is often reported in terms of the exhibit's attracting power (number of visitors who stop at the exhibit) and holding power (amount of time spent by visitors at the exhibit). Occasionally, the visitor's engagement level (degree to which the visitor pays attention to the exhibit) is also used as an assessment of the exhibit's educational impact. In this study, 154 visitors to a science museum discovery space were observed as they interacted freely with the exhibits. The exhibits were categorized into five different styles based upon three criteria: (1) high or low interaction; (2) concrete or abstract presentation; and (3) simple or complex information presented. Data indicated significant differences between exhibit style and attraction, holding power, and visitor engagement levels. Attraction levels were highest for exhibits with concrete presentations. Holding power was highest for exhibits with high interaction and concrete presentations. Engagement levels were highest for high interaction exhibits. Information from this study may be of interest to museum educators and to those who design and evaluate museum exhibits. © 1995 John Wiley & Sons, Inc.
Contextual settings, science stories, and large context problems: Toward a more humanistic science education
Authors: Stinner Arthur 
Published: October 2006

AbstractThis article addresses the need for and the problem of organizing a science curriculum around contextual settings and science stories that serve to involve and motivate students to develop an understanding of the world that is rooted in the scientific and the humanistic traditions. A program of activities placed around contextual settings, science stories, and contemporary issues of interest is recommended in an attempt to move toward a slow and secure abolition of the gulf between scientific knowledge and “common sense” beliefs. A conceptual development model is described to guide the connection between theory and evidence on a level appropriate for children, from early years to senior years. For the senior years it is also important to connect the activity of teaching to a sound theoretical structure. The theoretical structure must illuminate the status of theory in science, establish what counts as evidence, clarify the relationship between experiment and explanation, and make connections to the history of science. The article concludes with a proposed program of activities in terms of a sequence of theoretical and empirical experiences that involve contextual settings, science stories, large context problems, thematic teaching, and popular science literature teaching. © 1995 John Wiley & Sons, Inc.
Sudden deterioration in nonclassical infantile‐onset Pompe disease responding to alglucosidase alfa infusion therapy: A case report
Authors: Pascual‐Pascual S. I. , Rubio P. , Albajara L. , Gutierrez M. , Chabas A. , Alvarado F. 
Published: October 2006

SummaryA patient with atypical infantile Pompe disease suffered acute respiratory insufficiency at the age of 8 years which resulted in complete immobilization and dependence on assisted ventilation. Shortly after initiation of enzyme replacement therapy, she regained her mobility and, after 20 months of treatment, she now leads an almost normal life with limited restrictions.