bluuebunny/crossref_metadata_2025_split huggingface dataset:
Katalyse in der Totalsynthese von Bryostatin 16
Authors: Miller Aubry K. 
Published: March 2009

AbstractMit zwei Additionen zum Produkt: Eine Totalsynthese von Bryostatin 16 zeichnet sich durch zwei Übergangsmetall‐katalysierte Additionen aus. Die erste liefert Ring B und ermöglicht die Zuordnung seiner relativen Konfiguration; die zweite schließt den Makrocyclus mithilfe einer seltenen Isomerisierung. Die beiden Reaktionen benötigen weder Substrataktivierung, noch bilden sie Nebenprodukte. Die Makrocyclisierung ist eine effiziente Alternative zu traditionellen Verfahren.magnified image
Titelbild: Dicationic Sulfur Analogues of N‐Heterocyclic Silylenes and Phosphenium Cations (Angew. Chem. 12/2009)
Authors: Martin Caleb D. , Jennings Michael C. , Ferguson Michael J. , Ragogna Paul J. 
Published: March 2009

AbstractHochreaktive elektrophile Verbindungen mit mehrfach positiv geladenen Hauptgruppenelementen im Zentrum sind generell schwierig zu isolieren. In der Zuschrift auf S. 2244 ff. beschreiben P. J. Ragogna et al. die Synthese und Charakterisierung von Salzen mit Schwefel(II)‐Dikationen, die durch zwei chelatisierende Stickstoffatome stabilisiert sind. Bei ihnen handelt es sich um die ersten schwefelbasierten Analoga N‐heterocyclischer Silylene, und es sind die jüngsten Beispiele von Verbindungen zweiwertiger p‐Block‐Elemente. Bildentwurf: Mitch Zimmer.magnified image
Innentitelbild: Bifunctional Dendrimers: From Robust Synthesis and Accelerated One‐Pot Postfunctionalization Strategy to Potential Applications (Angew. Chem. 12/2009)
Authors: Antoni Per , Hed Yvonne , Nordberg Axel , Nyström Daniel , von Holst Hans , Hult Anders , Malkoch Michael 
Published: March 2009

AbstractDie Chemoselektivität der Klick‐Chemie wurde für die Synthese einer neuen Gruppe difunktioneller AB2C‐Dendrimere mit Acetylen/Azidgruppen im Innern und Hydroxygruppen an der Peripherie genutzt. M. Malkoch et al. stellen in der Zuschrift auf S. 2160 ff. einen einfachen Zugang zu zwei Gerüsttypen vor. Die Nützlichkeit der AB2C‐Dendrimere wurde durch ihren Einsatz zur nachträglichen Eintopffunktionalisierung, bei der Entwicklung dendritischer Nanopartikel und zur Bildung von Hydrogelen illustriert.magnified image
Telomerization: Advances and Applications of a Versatile Reaction
Authors: Behr Arno , Becker Marc , Beckmann Thomas , Johnen Leif , Leschinski Julia , Reyer Sebastian 
Published: March 2009

AbstractA chameleonic reaction: The transition‐metal‐catalyzed telomerization of 1,3‐dienes with different nucleophiles leads to the synthesis of numerous products which can be applied in the cosmetic and pharmaceutical industry as well as in polymers and flavors. This Review shows the versatility of the telomerization based on recent research and industrial applications.magnified imageThe transition‐metal catalyzed telomerization of 1,3‐dienes with different nucleophiles leads to the synthesis of numerous products, such as sugar ethers, substituted lactones, or terpene derivatives, which can be applied in the cosmetic and pharmaceutical industry as well as in polymers and flavors. The reaction can be controlled by the choice of the catalytic system, the feedstock, and the reaction conditions. Since telomerization was developed in 1967, there have been many efforts to utilize this reaction. Herein we give an overview of the versatility of telomerization based on examples from research and industry, particular emphasis is placed on catalyst and process development as well as mechanistic aspects.
Catalysis in the Total Synthesis of Bryostatin 16
Authors: Miller Aubry K. 
Published: March 2009

AbstractAdding up: A recent total synthesis of bryostatin 16 is highlighted by two transition‐metal‐catalyzed addition reactions. The first forges the B ring while establishing its relative stereochemistry. The second closes the macrocycle with a rare isomerization. These reactions neither require substrate activation nor do they generate byproducts. The powerful macrocyclization should be considered alongside more traditional methods.magnified image
Unprecedented Selectivity via Electronic Substrate Recognition in the 1,4‐Addition to Cyclic Olefins Using a Chiral Disulfoxide Rhodium Catalyst
Authors: Bürgi Justus J. , Mariz Ronaldo , Gatti Michele , Drinkel Emma , Luan Xinjun , Blumentritt Sascha , Linden Anthony , Dorta Reto 
Published: March 2009

AbstractFrom zero to hero? Sulfoxides are generally not considered useful ligand entities in asymmetric metal catalysis. However, a chiral disulfoxide as a chelating ligand in the rhodium‐catalyzed 1,4‐addition of aryl boronic acids to cyclic, α,β‐unsaturated ketones and esters gives impressive catalytic results, thus opening the door to future applications of this new chiral ligand class.magnified image
Cover Picture: Dicationic Sulfur Analogues of N‐Heterocyclic Silylenes and Phosphenium Cations (Angew. Chem. Int. Ed. 12/2009)
Authors: Martin Caleb D. , Jennings Michael C. , Ferguson Michael J. , Ragogna Paul J. 
Published: March 2009

AbstractHighly reactive electrophilic compounds centered around multicationic main‐group elements are notoriously difficult to isolate. In the Communication on page 2210 ff., P. J. Ragogna and co‐workers describe the synthesis and characterization of salts of sulfur(II) dications stabilized by two chelating nitrogen atoms. These species are the first sulfur‐based analogues of N‐heterocyclic silylene compounds and are the most recent addition to the family of compounds featuring divalent p‐block elements. Mitch Zimmer is acknowledged for the cover design.magnified image
Thermal properties of hexadecane encapsulated in poly(divinylbenzene) particles
Authors: Chaiyasat Preeyaporn , Suzuki Toyoko , Minami Hideto , Okubo Masayoshi 
Published: March 2009

AbstractThe thermal properties ofn‐hexadecane (HD) encapsulated in crosslinked capsule particles containing a water and/or air domain were studied from the viewpoint of heat‐storage applications. The capsule particles were prepared by the microsuspension polymerization of divinylbenzene at 70°C with the self‐assembling of phase‐separated polymer method that we developed. In the differential scanning calorimetric thermograms, pure HD had a single solidification temperature (Ts) peak at 15°C, whereas the encapsulated HD containing a water domain had two peaks at 6 and 1°C. That is, the encapsulated HD containing the water domain required a longer time and lower temperature to complete the solidification than pure HD, which was negative for heat‐storage applications. However, once the particles were dried and the water domain was replaced with air, the problem with the partially loweredTsimproved. The air domain was also found in the encapsulated HD core after solidification because of the shrinkage of HD. The presence of the air domain did not affect the thermal stability of the encapsulated HD. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Bioactive peptides, networks and systems biology
Authors: Boonen Kurt , Creemers John W. , Schoofs Liliane 
Published: March 2009

AbstractBioactive peptides are a group of diverse intercellular signalling molecules. Almost half a century of research on this topic has resulted in an enormous amount of data. In this essay, a general perspective to interpret all these data will be given. In classical endocrinology, neuropeptides were thought of as simple signalling molecules that each elicit one response. However, the fact that the total bioactive peptide signal is far from simple puts this view under pressure. Cells and tissues express many different bioactive peptides and they are also able to respond to many different bioactive peptides, indicating that multiple receptors and signal transduction pathways are present in a single cell. Therefore, the authors suggest that the bioactive peptide signalling system should be regarded in the context of network and systems biology. Bioactive peptides can best be viewed as an extension of the protein interaction network that allows regulating and fine‐tuning the metabolism of the different cells and tissues in the body. The cell thus responds to the ‘peptidome’ instead of to a single peptide. The intracellular part of this signalling network consists of the various signalling transduction cascades. Recently, new systems biology approaches have emerged for the modelling of cell signalling. The network and systems biology approach is also able to shed new light on the evolution of intercellular signalling.
Animal evolution during domestication: the domesticated fox as a model
Authors: Trut Lyudmila , Oskina Irina , Kharlamova Anastasiya 
Published: March 2009

AbstractWe review the evolution of domestic animals, emphasizing the effect of the earliest steps of domestication on its course. Using the first domesticated species, the dog (Canis familiaris), for illustration, we describe the evolutionary peculiarities during the historical domestication, such as the high level and wide range of diversity. We suggest that the process of earliest domestication via unconscious and later conscious selection of human‐defined behavioral traits may accelerate phenotypic variations. The review is based on the results of a long‐term experiment designed to reproduce early mammalian domestication in the silver fox (Vulpes vulpes) selected for tameability or amenability to domestication. We describe changes in behavior, morphology and physiology that appeared in the fox during its selection for tameability, which were similar to those observed in the domestic dog. Based on the data of the fox experiment and survey of relevant data, we discuss the developmental, genetic and possible molecular genetic mechanisms underlying these changes. We ascribe the causative role in evolutionary transformation of domestic animals to the selection for behavior and to the neurospecific regulatory genes it affects.
Human embryonic stem cells: caught between a ROCK inhibitor and a hard place
Authors: Krawetz Roman J. , Li Xiangyun , Rancourt Derrick E. 
Published: March 2009

AbstractSince their derivation, human embryonic stem (hES) cells have been used for a variety of applications including developmental biology, pathology, chemical biology, genomics, and proteomics. However, their most important potential application is the generation of cells and tissues, which can be used for cell‐based therapies. One of the main drawbacks of hES cell culture is that they are particularly sensitive to dissociation, which is required for passaging, expansion, cryopreservation, and other applications. Recently, it has been discovered that an inhibitor of Rho kinase (ROCKi; Y‐27632) increases the survival rate of dissociated, single hES cells. This breakthrough has allowed new methods in hES cell culture to be developed, with the promise of increasing hES cell numbers into the realm of clinical relevance. In our studies demonstrating that ROCKi dramatically increases hES cell cryopreservation efficiency, we have observed that ROCKi treatment does not decrease hES cell's susceptibility to apoptosis. Rather, we hypothesize that ROCKi treatment desensitizes single hES cells to their environment reducing the odds that individual cells will undergo anoikis.
The rapidly expanding CREC protein family: members, localization, function, and role in disease
Authors: Honoré Bent 
Published: March 2009

AbstractAlthough many aspects of the physiological and pathophysiological mechanisms remain unknown, recent advances in our knowledge suggest that the CREC proteins are promising disease biomarkers or targets for therapeutic intervention in a variety of diseases. The CREC family of low affinity, Ca2+‐binding, multiple EF‐hand proteins are encoded by five genes,RCN1,RCN2,RCN3,SDF4, andCALU, resulting in reticulocalbin, ER Ca2+‐binding protein of 55 kDa (ERC‐55), reticulocalbin‐3, Ca2+‐binding protein of 45 kDa (Cab45), and calumenin. Alternative splicing increases the number of gene products. The proteins are localized in the cytosol, in various parts of the secretory pathway, secreted to the extracellular space or localized on the cell surface. The emerging functions appear to be highly diverse. The proteins interact with several different ligands. Rather well‐described functions are attached to calumenin with the inhibition of several proteins in the endoplasmic or sarcoplasmic reticulum membrane, the vitamin K12,3‐epoxide reductase, the γ‐carboxylase, the ryanodine receptor, and the Ca2+‐transporting ATPase. Other functions concern participation in the secretory process, chaperone activity, signal transduction as well as participation in a large variety of disease processes.
Erythropoietin and the skin: a role for epidermal oxygen sensing?
Authors: Paus Ralf , Bodó Enikő , Kromminga Arno , Jelkmann Wolfgang 
Published: March 2009

AbstractErythropoietin (EPO), long appreciated as the chief endocrine regulator of red blood cell formation, is now recognized to exert many additional functions outside the bone marrow. Thus, the quest is on to define the full range of EPO functions in the physiology and pathology of non‐hematopoietic tissues. Two recent studies in man and mice have highlighted the importance of the mammalian skin as one peripheral tissue with a previously unsuspected role in EPO biology; both, as a target and as a source of EPO. In addition, the skin has been proposed to function as an oxygen sensor. The present hypothesis essay critically reviews the currently available evidence for this and provides a unifying theoretical scenario for intracutaneous EPO functions and for a potential role of the skin in the control of EPO production. Mainly, we propose that the skin itself directly contributes to the up‐regulation of EPO plasma levels in response to hypoxia.
The evolution of the study of anatomy in Japan
Authors: Tubbs R. Shane , Loukas Marios , Kato David , Ardalan Mohammad R. , Shoja Mohammadali M. , Gadol Aaron A. Cohen 
Published: March 2009

AbstractThe following review focuses on how the study of anatomy in Japan has evolved throughout the centuries; specifically, we investigate anatomical knowledge during the primitive, ancient, feudal, and early modern periods of Japanese history. Early vague and mythical anatomical concepts derived from China prevailed for many centuries in Japan. Kajiwara wrote one of the earliest anatomical works in 1302. As a science, anatomy was the first basic science to be established in Japan, beginning simplistically during the 1600s and flourishing more recently with the onset of Meiji Restoration. As a result, Japan has produced several of the most influential anatomists of the 20th century, including Buntaro Adachi, who added detail to our knowledge of the vascular system and its variations; and Sunao Tawara, who discovered the atrioventricular node. Herein, we discuss the ways in which Japan has added to and promoted the anatomical sciences. Clin. Anat. 22:425–435, 2009. © 2009 Wiley‐Liss, Inc.
The correlation between femoral condyle radii and subject height
Authors: Malek I.A. , Moorehead J.D. , Abiddin Z. , Montgomery S.C. 
Published: March 2009

AbstractIn the sagittal plane, the distal femoral condyles can be modeled using anterior and posterior circle segments. The aim of this study was to investigate how the radii of these segments vary with subject height. The MRI scans of 20 male and 20 female knees were analyzed with a computer to extract the radii of each condyle segment. These radii were then correlated with the patient's height. The anteromedial radii ranged from 22.6 to 32.6 mm. The posteromedial radii ranged from 15.4 to 26.3 mm. The anterolateral radii ranged from 19.7 to 30.4 mm. The posterolateral radii ranged from 15.2 to 23.6 mm. The radii had a strong correlation with patient height, with some differences between sexes. Linear regressions of the data yielded equations for estimating condyle radii from height. These radii estimations can be helpful in the clinical assessment of knee movement and treatment outcome. Clin. Anat. 22:517–522, 2009. © 2009 Wiley‐Liss, Inc.
A web‐based tool for teaching neural network concepts
Authors: Ugur Aybars , Kinaci Ahmet Cumhur 
Published: March 2009

AbstractAlthough neural networks (NN) are important especially for engineers, scientists, mathematicians and statisticians, they may also be hard to understand. In this article, application areas of NN are discussed, basic NN components are described and it is explained how an NN work. A web‐based simulation and visualization tool (EasyLearnNN) is developed using Java and Java 2D for teaching NN concepts. Perceptron, ADALINE, Multilayer Perceptron, LVQ and SOM models and related training algorithms are implemented. As a result, comparison with other teaching methods of NN concepts is presented and discussed. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 449–457, 2010; View this article online at wileyonlinelibrary.com; DOI 10.1002/cae.20184
A novel web‐based laboratory for DC motor experiments
Authors: Colak Ilhami , Demirbas Sevki , Sagiroglu Seref , Irmak Erdal 
Published: March 2009

AbstractThis article introduces a novel web‐based DC motor laboratory, called NeTRe‐LAB, to support teaching electrical machines. The NeTRe‐LAB includes favorable animations to facilitate understanding characteristics of the DC motor, interactive DC motor models for instructive simulations, and web‐based experiments with online monitoring features. To illustrate the current operations, remote access to an experimental setup of a DC motor has been provided and the speed control of it has been realized over Internet. The evaluation results have shown that the NeTRe‐LAB presented in this study provides encouraging aspects, services, and support system for higher education. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 19: 125–135, 2011
A new developed educational approach to improve conventional teaching methodology of the power electronics laboratory
Authors: Yamin H. Y. , Altawil I. A. , Al‐Ajlouni A. F. , Al‐Fahoum A. S. 
Published: March 2009

AbstractThis paper proposes a new computerized educational approach to teach the power electronics laboratory. It describes PSpice implementation of the core power electronic circuits that depend on thyristor circuits to identify behaviors with load variations. It uses the developed simulation models to support and enhance power electronics education at the undergraduate level. These simulations successfully integrate the contents of the power electronic laboratory course. A study of the impact of these simulations on the results of the students showed that it helped them to master the course contents and to gain better grades. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 19: 193–200, 2011
Multi‐sensory method for teaching‐learning recursion
Authors: Katai Zoltan 
Published: March 2009

AbstractIn this paper, we are going to introduce a new multi‐sensory method and software, which improve the teaching‐learning process of the recursive procedures and functions. The presented method can also be categorized as a blending or hybrid teaching‐learning strategy that applies to technologically enhanced pedagogy. (The software was initially designed to be utilized especially in the teaching phase of the educational process, but it can also be efficiently used as an e‐learning tool.) © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 19: 234–243, 2011
Using a pattern system to increase project complexity in groupware courses
Authors: Licea Guillermo 
Published: March 2009

AbstractCOCHI is a flexible and easy to use software pattern system that supports the development of groupware applications. This paper describes COCHI and the experiences using this pattern system to enhance project complexity in undergraduate and graduate groupware courses in three Mexican universities. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 19: 280–285, 2011
A modular virtual reality system for engineering laboratory education
Authors: Hashemipour Majid , Manesh Hamed Farahani , Bal Mert 
Published: March 2009

AbstractThe globalization trend has affected the tertiary education sector, resulting in an increased flow of both students and academics across borders. Economic pressures on universities and the emergence of new technologies have spurred the creation of new systems in engineering education. The recent advances in computer graphics have exposed great potential in education at all levels. The Virtual Reality (VR) is a promising technology which aims to assist the students in the visualization of concepts and to provide immediate graphical feedback during the learning process. This article presents a modular interactive teaching package, called Virtual Learning System (VLS), which can be used by people with little prior computer experience. VLS provides a comprehensive and conductive yet dynamic and interactive environment that can be incorporated into various courses in the field of Mechanical and Manufacturing Engineering. The evaluation of the learning process with the developed system has been done through laboratory reports, lab quizzes and questionnaires implemented with a tutorial monitoring application. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 19: 305–314, 2011
Structure Formation Principles and Reactivity of Organolithium Compounds
Authors: Gessner Viktoria H. , Däschlein Christian , Strohmann Carsten 
Published: March 2009

AbstractOrganolithium chemistry! An overview of the structure formation principles and the strong structure–reactivity relationship of lithium organics is given. By means of the commonly used lithium bases the deaggregation of the oligomeric parent structures to small adducts is presented (see examples) and compared to the related chemistry of lithiosilanes.magnified imageThe structure–reactivity relationship is an important feature of organolithium compounds. The knowledge of the structure of reactive species is crucial for the elucidation of reaction mechanisms and the understanding of observed selectivities. This concept article gives an overview over the structural principles of lithium organics and their Lewis base coordinated complexes in the solid state. The transition from the oligomeric parent structures to smaller adducts, such as dimers and monomers, as well as special degrees of aggregation is presented. Besides the commonly used alkyllithium compounds, a short overview over the structural principles of the higher homologous silyllithium compounds is given. Moreover, the structure–reactivity relationship is depicted by means of the reactivity of the Lewis bases towards intramolecular decomposition reactions with the organolithium compound. Selected examples confirm the importance of structure elucidation for the understanding of mechanistic pathways and selectivities.
Nickel(II) Complexes Bearing NH2CH2CH2CH2NH2 and o‐C6H4(NH2)2 Ligands: Synthesis, Structures and Their Ethylene Polymerization Behavior
Authors: LU Xiaoming , WANG Zhen , LIU Man 
Published: March 2009

AbstractTwo nickel complexes [Ni(NH2CH2CH2CH2NH2)3]Cl2 (1) and [Ni(C6H4N2H4)2Cl2] (2) have been obtained and characterized by IR and single crystal X‐ray diffraction analysis. In complex 1, the nickel atom was in a chiral pseudo‐octahedral [NiN6] geometry environment, which was coordinated by three 1,3‐propylenediamine to form three six‐membered rings. However in complex 2, besides connected with two o‐phenylenediamine through four Ni–N bonds to form two five‐membered rings, the nickel center was coordinated by two Cl to form trans‐Ni‐Cl2, which was different from general reported diimine nickel complexes. Activated with MAO, MMAO or Et2AlCl, these nickel complexes exhibited considerable good catalytic activity [up to 3.59×106 g·mol−1·h−1 for complex 2] for ethylene polymerization with main products as dimers or trimers of ethylene.