bluuebunny/crossref_metadata_2025_split huggingface dataset:
Asymmetrische Selbstreplikation chiraler 1,2‐Aminoalkohole durch hochenantioselektive, autoinduktive Reduktion
Authors: Shibata Takanori , Takahashi Tomohide , Konishi Takashi , Soai Kenso 
Published: July 2007

Das Produkt als Auslöser der Enantioselektivität ‐ dieser Ansatz kennzeichnet die hier vorgestellte Reduktion von α‐Aminoketonen mit Lithiumaluminiumhydrid [G1. (1)]. Indem das Reduktionsmittel vor seinem Einsatz mit dem Produktalkohol als chiralem Liganden modifiziert wird, lassen sich bei Ausbeuten zwischen 65 und 93% ee‐Werte zwischen 69 und 90% erreichen.magnified image
Insertion von Carbenoiden in Cp‐H‐Bindungen von Ferrocenen: ein enantioselektiv‐katalytischer Zugang zu planar‐chiralen Ferrocenen
Authors: Siegel Stephan , Schmalz Hans‐Günther 
Published: July 2007

Nicht nur signifikante Enantioselektivitäten, sondern auch noch deutlich höhere chemische Ausbeuten als mit achiralen Katalysatoren ergab die asymmetrische Variante der übergangsmetallkatalysierten Cyclisierung von Diazoketonen wie 1. Die bei der Funktionalisierung von Benzolderivaten bewährte Carbenchemie wurde hier erstmals auf Ferrocene übertragen.magnified image
1,8‐Bis(allylstannyl)naphthalinderivate als neutrale Allylierungsreagentien: Steigerung der Reaktionsgeschwindigkeit als Folge einer durch Chelatisierung erzeugten Lewis‐Acidität
Authors: Asao Naoki , Liu Pingli , Maruoka Keiji 
Published: July 2007

Eine große Vielfalt an Carbonylverbindungen kann mit 1 unter neutralen Bedingungen allyliert werden. Bei Dicarbonylverbindungen entstehen die Produkte 2 chemoselektiv. Die Triebkraft der Reaktion wird der latenten Lewis‐Acidität zugeschrieben, die durch die Chelatbildung zwischen dem neutralen, zweizähnigen Bisstannan und der Carbonylgruppe (Struktur A) “freigesetzt” wird.magnified image
Photochemische Synthese von Polyrotaxanen aus Stilbenpolymeren und Cyclodextrinen
Authors: Herrmann Wolfgang , Schneider Maria , Wenz Gerhard 
Published: July 2007

Der zusätzliche Einschluß von Stilbenmonomeren führt zu einer supramolekularen Stabilisierung kinetisch labiler, molekularer Perlenketten, die aus Cyclodextrinen mit polymeren Stilbenen erhalten werden. Dies ermöglicht die photochemische Modifizierung des Polymers unter Bildung eines Polyrotaxans mit Tetraphenylcyclobutaneinheiten (siehe unten).magnified image
Totalsynthese von Eleutherobin
Authors: Nicolaou Kyriacos Costa , Van Delft Floris , Ohshima Takashi , Vourloumis Dionisios , Xu Jinyou , Hosokawa Seijiro , Pfefferkorn Jeffrey , Kim Sanghee , Li Tianhu 
Published: July 2007

Taxolähnliche Wirkung hat einer der vielversprechendsten Antitumorwirkstoffe, die in den letzten Jahren aus der Natur isoliert worden sind, Eleutherobin 1. Die erste Totalsynthese dieser Verbindung eröffnete auch einen Weg zu zwei Derivaten, anhand derer die ersten Struktur‐Wirkungs‐Beziehungen innerhalb der Eleutherobin‐Familie ermittelt wurden.magnified image
Synthese, Struktur und Bindungscharakteristika von Indacen‐Dianionen
Authors: Cary Douglas R. , Green Jennifer C. , O'Hare Dermot 
Published: July 2007

Mit Lithium und mit Kalium gelang die Reduktion von Tetra‐tert‐butyl‐s‐Indacen zum Dianion 1. Beide Salze konnten NMR‐spektroskopisch und röntgenographisch charakterisiert werden. Das polycyclische Carbanionen‐Fragment zeichnet sich ‐ wie auch die Neutralverbindung ‐ durch ein delokalisiertes π‐Elektronensystem aus. Durch Dichtefunktionalrechnungen wurden Bindungscharakteristika vorausgesagt, die mit den experimentellen Befunden in Einklang sind.magnified image
Schnelle und hochselektive Spaltung von cyclischen Ribonucleosid‐2′,3′‐monophosphaten durch zweikernige CuII‐Komplexe
Authors: Liu Shanghao , Luo Zhiyong , Hamilton Andrew D. 
Published: July 2007

Zwei Eigenschaften, die sich bisher ausschlossen, sind in den Komplexen 1 und 2 vereint. Sie zeigen sowohl hohe Aktivitäten als auch hohe Selektivitäten bei der Hydrolyse von cyclischen Nucleosid‐2′,3′‐monophosphaten als Modellverbindungen für RNA. Bei 1 ist es vor allem die Regioselektivität, bei 2 die Basenselektivität, die bemerkenswert ist.magnified image
Schaltbare Koordinationsgeometrien: pH‐gesteuerter Wechsel zwischen trigonal‐prisma‐tischer und oktaedrischer Metallkoordination eines zweikernigen Cobalt(II)‐Komplexes
Authors: Wendelstorf Carsten , Krämer Roland 
Published: July 2007

Trigonal‐prismatisch bei pH 4, oktaedrisch bei pH 6.5 ‐ durch Änderung des pH‐Werts läßt sich die Koordinationsgeometrie eines makrocyclischen Dicobalt(II)‐Komplexes reversibel schalten. Induziert wird der Wechsel der Koordinationsgeometrie durch Verbrückung der Metallionen über ein Hydroxid‐Ion (siehe unten).magnified image
Von D‐Glucose zu einem neuen chiralen Cyclooctenon
Authors: Werschkun Barbara , Thiem Joachim 
Published: July 2007

Unter Verlust der Kohlenhydratstruktur lagert sich das doppelt ungesättigte Saccharidderivat 1 sigmatrop um. Damit entsteht aus D‐Glucose in einer einfachen Reaktionssequenz 2, ein hochfunktionalisierter achtgliedriger Carbacyclus.magnified image
Die Spaltung von DNA mit Bis(phenanthrolin)kupfer verläuft ohne intramolekulare Wasserstoffwanderung
Authors: Zelenko Ottilie , Gallagher James , Sigman David S. 
Published: July 2007

An C‐1′H und nicht an C‐2′H beginnt die oxidative Spaltung von DNA mit der chemischen Nuclease [Cu(phen)2]+/H2O2. Dies ergaben Experimente mit DNA, die 1′‐deuterierte Thymidinreste enthält (1. Schritt der Reaktionsfolge siehe unten). Würde 2′H im 1. Schritt abstrahiert, so sollten eine Einelektronen‐Oxidation und eine H/D‐Wanderung folgen, wofür kein Beleg gefunden wurde.magnified image
Nichtkovalente Wechselwirkungen bei Organometallverbindungen: intramolekulare Metall‐Kohlenstoff‐Ionenpaarbildung bei Zirconium‐Borat‐Betainen
Authors: Karl Jörn , Erker Gerhard , Fröhlich Roland , Zippel Frank , Bickelhaupt Friedrich , Goedheijt Marcel Schreuder , Akkerman Otto S. , Binger Paul , Stannek Jörg 
Published: July 2007

Über die Art der intramolekularen Stabilisierung bei Zr‐B(C6F5)3‐Betain‐Systemen entscheidet die Anordnung der Substituenten der Allyleinheit: E‐Konfiguration führt zu Zr‐F‐Koordination (1), bei Z‐Konfiguration ist die Bildung eines inneren Zr‐[B]CH2‐Ionenpaares günstiger (2).magnified image
Vierzig Jahre Evolution im Reagenzglas
Authors: Joyce Gerald F. 
Published: July 2007

AbstractVierzig Jahre ist es her, dass Spiegelman und Mitarbeiter demonstrierten, wie RNA‐Moleküle in vitro (“im Reagenzglas”) evolviert werden können. Damit war einwandfrei festgestellt, dass die Darwinsche Evolution ein chemischer Prozess ist, und der Weg für zahlreiche Folgeexperimente zur gerichteten Evolution war geebnet. Auch die Chemie fand Inspiration in Spiegelmans bahnbrechenden Arbeiten und den daraus hervorgegangenen Entwicklungen, die das Gebiet bis dicht an die Erschaffung von Leben im Labor geführt haben. Dieser Aufsatz gibt einen Überblick über die Konzepte und Methoden zur gerichteten Evolution von RNA‐Molekülen im Reagenzglas.
Review modeling the free solution and gel electrophoresis of biopolymers: The bead array‐effective medium model
Authors: Allison Stuart A. , Pei Hongxia , Xin Yao 
Published: July 2007

AbstractFree solution and gel electrophoresis is an extremely useful tool in the separation of biopolymers. The complex nature of biopolymers, coupled with the usefulness of electrophoretic methods, has stimulated the development of theoretical modeling over the last 30 years. In this work, these developments are first reviewed with emphasis on Boundary Element and bead methodologies that enable the investigator to design realistic models of biopolymers. In the present work, the bead methodology is generalized to include the presence of a gel through the Effective Medium model. The biopolymer is represented as a bead array. A peptide, for example, made up of N amino acids is modeled as 2N beads. Duplex DNA is modeled as a discrete wormlike chain consisting of touching beads. The technical details of the method are placed in three Appendices. To illustrate the accuracy and effectiveness of the approach, two applications are considered. Model studies on both the free solution mobility of 73 peptides ranging in size from 2 to 42 amino acids, and the mobility of short duplex DNA in dilute agarose gels are discussed. © 2007 Wiley Periodicals, Inc. Biopolymers 87: 102–114, 2007.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Our commitment to enforcing good policy governance
Authors: Stockman David 
Published: July 2007

AbstractDavid Stockman, senior vice president of Lawry's Restaurants, Inc., chairs the board of the California Restaurant Association (CRA). The association represents California's $28.5 billion restaurant industry. The CRAboard reached a pivotal point on March 8, 1999, as it adopted new, carefully crafted policies to put the Policy Governance model into effect. Here are Stockman's introductory words at the March 8 board meeting. We include them to illustrate one chair's conscientious effort to remind his colleagues, gently but firmly, not only of the commitment to discipline. the board has adopted but also of the obligation the board has given him to enforce that discipline.
Just how should boards communicate with owners?
Authors: Kradel Eileen 
Published: July 2007

AbstractIn the Last Issue of Board Leadership, the article “Understandingand Linking with the Moral Ownership of Your Organization” explored what it means for boards to embrace their moral accountability to owners. The article pointed out that linking with owners— with the people for whom the board members act as trustees—is one of the main jobs boards take on under Policy Governance. What does this mean in action? What does this linkage really look like? To address these questions, Board Leadership asked the chair of the board of trustees of Westark College in Little Rock, Arkansas, to describe how the board set about the work of linking with owners. Westark is new to Policy Governance; the board adopted it formally in early 1999 and met for the first time as a Policy Governance board in May. As Eileen Kradel describes, connecting with owners is a defining feature of the work of adopting and implementing the model.
Taking policy governance to the mainstream
Authors: Oliver Caroline 
Published: July 2007

AbstractHave you ever expressed your enthusiasm for Policy Governance only to be met by a blank stare? Do you wonder what could be done to create greater awareness of the advantages of Policy Governance both for your own board and for others? Caroline Oliver, Policy Governance consultant, general editor of The Policy Governance Fieldbook, and designated chair of the soon‐to‐be‐launched Policy Governance Association, looks to the world of high technology for some answers.
On creating a new association
Authors: Oliver Caroline 
Published: July 2007

AbstractCaroline Oliver, who writes regularly for Board Leadership, has recently been involved in the startup of a new association, the International Policy Governance Association, which she now chairs. Here she offers a case history, sharing some of the governance challenges and lessons learned iri buildingan organization and its governing structure from the ground up. If you have ideas or views that you would like to pass on to the association, e‐mail Caroline Oliver at coliver@cgo.wave.ca.
How to tell board means from staff means
Authors: Carver John , Carver Miriam 
Published: July 2007

AbstractThe distinction between ends and means will be familiar to readers of Board Leadership. The board determines the broadest organizational ends, leaving to the staff farther ends as well as all organizational means that fall within board‐stated limits. Yet the board itself has operational concerns, such as scheduling meetings and setting agendas; that is to say, the board has its own means. Though this situation seems uncomplicated, in fact it generates considerable confusion and opportunity for the blurring of roles. In this article, John and Miriam Carver clarify what means belong to the staff and what means belong to the board.
CVD Reactions of TiCl4 with Ammonia: a Quantum Chemical Study
Authors: Huang Ting‐Ting , Tan Kai , Lin Meng‐Hai , Zhang Qian‐Er 
Published: July 2007

AbstractBased on density functional calculations, the mechanism and the energetic course of the chemical vapor deposition (CVD) reaction of TiCl4 with NH3 were studied at the level of B3LYP with 6‐311g(d) basis set. Furthermore, the polymerization processes of dimerization, trimerization and tetramerization were investigated. The calculation results indicate that the formation of polymers is favored at the elimination reaction. On the basis of the calculated energetics, a possible mechanism of the reduction reaction has been proposed.
DNA Cleavage Promoted by Cu2+ Complex of N,N′‐Bis(2‐aminoethyl)‐2,6‐pyridinedicarboxamide
Authors: Li Ying , Sheng Xin , Shao Ying , Lu Guo‐Yuan 
Published: July 2007

AbstractThe interaction of Cu2+ complex of N,N′‐bis(2‐aminoethyl)‐2,6‐pyridinedicarboxamide (BAP) with DNA was studied by agarose gel electrophoresis analysis. The results indicate that the BAP‐Cu2+ complex can promote the cleavage of phosphodiester bond of supercoiled DNA at physiological condition, which is 3.2×106 times higher than DNA natural degradation. A hydrolytic cleaving mechanism through the cooperation of copper ions and functional amino groups was proposed.
Detecting deviations from pure EOF during CE separations
Authors: O'Grady John F. , Noonan Kathryn Y. , McDonnell Patrick , Mancuso Aaron J. , Frederick Kimberley A. 
Published: July 2007

AbstractCE separations are known for their high separation efficiencies. In systems with EOF, the high efficiencies benefit from the flat, plug profile that is characteristic of EOF. When a velocity gradient is present, such as in separations which have nonuniform buffer ionic strength, surface adsorption or differences in the height of the ends of the capillary, a parabolic flow component is introduced. This deviation from purely EOF yields increased peak dispersion and a subsequent decrease in separation performance. This work details a rapid method for detecting deviations from ideal plug flow during the course of a separation using the radially averaged flow profile of a photobleached fluorophore added to the BGE. By comparing the ratio of two different data analysis procedures, deviations from ideal plug flow can be detected. This method allows rapid measurement of flow character and does not interfere with the concurrent separation. We demonstrate easy detection of the onset of hydrodynamic flow induced by both gravity siphoning and an ionic strength buffer discontinuity. A brief analysis of the radially averaged peak shapes is also presented.
High‐frequency behavior of power inductor windings using an accurate multiconductor transmission line model: input impedance evaluation
Authors: Faria J. A. Brandão 
Published: July 2007

AbstractThis research and tutorial paper is the second part of a work dedicated to the analysis and computation of the electromagnetic behavior of inductor windings operating at high‐frequency regimes—a critical issue for very fast transient overvoltage studies. The inductor winding, wound around a ferromagnetic core, containing a total number of N dielectric coated cylindrical turns, is modeled by using a multiconductor transmission line (MTL) approach (proximity effects being accounted) whose constitution and characterization was presented in a former paper. In the present work, we make use of the R, G, L, and C constitutive matrices of the structure in order to develop a modal analysis technique‐based formulation aimed at the evaluation of the winding's input impedance in the frequency‐domain. Results obtained show that the input impedance critically depends not only on the number of layers of the winding but also, and, more importantly, on the frequency, where resonance phenomena play a key role. Frequency‐domain analysis is complemented with simulation results in the time‐domain that clearly illustrate how critical and sensitive the system response can be under minute changes of the winding's excitation current. Copyright © 2007 John Wiley & Sons, Ltd.
Scapular angle osteomyogenous flap in postmaxillectomy reconstruction: Defect, reconstruction, shoulder function, and harvest technique
Authors: Clark Jonathan R. , Vesely Martin , Gilbert Ralph 
Published: July 2007

AbstractBackground.Maxillary reconstruction continues to challenge in terms of optimal aesthetic and functional outcomes. The aim of this study was to describe the utility of the scapular angle osteomyogenous flap in a series of maxillectomy patients and to examine the donor site morbidity.Methods.This is a retrospective series of 14 patients undergoing maxillectomy and either primary or secondary reconstruction. The scapular angle can be oriented vertically and horizontally. Aesthetic, functional, and operative morbidity is described. The Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire was used to examine shoulder and upper limb morbidity.Results.Perioperative morbidity occurred in 4 patients. There were no free flap failures. Functional and aesthetic outcomes were acceptable with all patients having intelligible speech and none requiring nutritional supplementation. The DASH was completed by 12 of 14 patients. The mean and median DASH scores were 10.6 and 13, respectively. All patients gained full range of shoulder movement by 6 months after surgery.Conclusions.The scapular angle flap is well suited for maxillary reconstruction and donor site morbidity is low. © 2007 Wiley Periodicals, Inc. Head Neck, 2008
Efficacy of neck treatment in patients with head and neck squamous cell carcinoma
Authors: Buck Gabriela , Huguenin Pia , Stoeckli Sandro J. 
Published: July 2007

AbstractBackground.Treatment of head and neck squamous cell carcinoma (HNSCC) addresses the primary tumor and the lymphatic drainage. Modalities for the neck are neck dissection and/or radiation therapy. In most cases, the neck is treated by the modality that seems more appropriate for the primary. The aim of this study was to analyze the results of the neck treatments either by neck dissection alone, by radiation therapy alone or by neck dissection followed by radiation therapy.Methods.This was a retrospective chart analysis of 699 patients treated for a previously untreated HNSCC. The primary endpoint was recurrence at the treated neck.Results.Two hundred eighty‐one (40%) patients underwent primary neck irradiation, 219 (31%) neck dissection alone, and 199 (29%) neck dissection followed by adjuvant irradiation. The 5‐year regional control rates after neck dissection alone were 83% for pN0, 75% for pN1, 60% for pN2a, 59% for pN2b, and 50% for pN2c; after radiation alone, 89% for cN0, 87% for cN1, 40% for cN2a, 60% for cN2b, and 48% for cN2c; and after neck dissection with adjuvant radiation, 86% for pN0, 96% for pN1, 100% for pN2a, 88% for pN2b, and 88% for pN2c.Conclusions.Radiation or neck dissection alone are efficient to control early neck disease. For advanced N2/3 neck disease, neck dissection followed by adjuvant radiation is highly efficient, whereas primary radiation results in a high number of regional failures. The literature suggests planned neck dissection to improve regional control for these patients. © 2007 Wiley Periodicals, Inc. Head Neck, 2008
Development of a biodegradable scaffold with interconnected pores by heat fusion and its application to bone tissue engineering
Authors: Shin Michael , Abukawa Harutsugi , Troulis Maria J. , Vacanti Joseph P. 
Published: July 2007

AbstractTissue engineering has been proposed as an approach to alleviate the shortage of donor tissue and organs by combining cells and a biodegradable scaffold as a temporary extracellular matrix. While numerous scaffold fabrication methods have been proposed, tissue formation is typically limited to the surface of the scaffolds in bone tissue engineering applications due to early calcification on the surface. To improve tissue formation, a novel scaffold with a hierarchical interconnected pore structure on two distinct length scales has been developed. Here we present the fabrication process and the application of the scaffold to bone tissue engineering. Porous poly(lactide‐co‐glycolide) (PLGA) scaffolds were made by combining solvent casting/particulate leaching with heat fusion. Porcine bone marrow‐derived mesenchymal stem cells (MSCs) were differentiated into osteoblasts and cultured on these scaffolds in vitro for 2, 4, and 6 weeks. Subsequently, the constructs were assessed using histology and scanning electron microscopy. The bone marrow‐derived osteoblasts attached well on these scaffolds. Cells were observed throughout the scaffolds. These initial results show promise for this scaffold to aid in the regeneration of bone. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
The challenge of restructuring a Yugoslav manufacturing organization
Authors: Martin C. J. 
Published: July 2007

AbstractPolitical change in central Europe and Russia is fuelling rapid economic change in which reorganization at the company level is fundamental to achieving the potential economic benefits. This article discusses one example of the restructuring of a manufacturing company in Yugoslavia, where organizational change was implemented to meet the demands of a rapid and radical change in the business environment. Achieving viability in a competitive global market and enabling entrepreneurial activation of stagnant assets were the objectives of the change. The processes involved in the planning and implementation of organizational change in the company ‘Dina’ are described, but not the detailed financial restructuring that accompanied this change.
Bladder diary measurements in asymptomatic males: Frequency, volume per void, and 24‐Hr volume
Authors: Tissot William , Amundsen Cindy L. , Diokno Ananias C. , Webster George D. , Coats Alfred C. ,   on behalf of the Bladder Diary Research Team
Published: July 2007

AbstractAimsTo collect bladder diary frequency and volume measurements from asymptomatic males and to use these data to develop clinical reference values.Materials and MethodsComputer processed three‐day bladder diaries were collected from 92 males (median age: 46.2 years; range: 20.6–84.6 years) defined as “asymptomatic” by questionnaire. Minimum (Vmin), maximum (Vmax), and average (Vavg) volume per void (Vol/Void), 24‐hr frequency (F24), and 24‐hr volume (V24) were studied. Relationships of Vol/Void and F24 to age and V24 and of V24 to age were investigated by regression analysis.ResultsVmax and Vavg increased as V24 increased and decreased with increasing age (P < 0.0005). We found no significant relationship between Vmin and age, but Vmin increased with increasing V24 (P < 0.0005). F24 increased with increasing V24 and increasing age (P < 0.0005). We found a concave downward, curvilinear relationship between age and V24, which, while it did not reach statistical significance, was very similar in shape to age versus V24 relationships found by other studies of larger datasets.ConclusionsOur results suggest that reference values of F24 and Vol/Void should be adjusted for their relationships to the patient's age and V24. Regression equations expressing these relationships can be used to make these adjustments. From frequency histograms of residuals the difference between the patient's actual and expected reference measurement can be ranked within the reference population as a percentile. We illustrate this method by using our results to calculate age‐ and V24‐adjusted 5% “normal limit” tables of F24, Vavg, and Vmax. Neurourol. Urodynam. 27:198–204, 2008. © 2007 Wiley‐Liss, Inc.