bluuebunny/crossref_metadata_2025 huggingface dataset:
Absorption, Light Emission, and Upconversion Properties of Tm2+‐Doped CsCaI3 and RbCaI3.
Authors: Beurer Eva , Grimm Judith , Gerner Pascal , Guedel Hans U.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
NaBH4/Charcoal: A New Synthetic Method for Mild and Convenient Reduction of Nitroarenes.
Authors: Zeynizadeh Behzad , Setamdideh Davood
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Efficient Demethylation of N,N‐Dimethylanilines with Phenyl Chloroformate in Ionic Liquids.
Authors: Imori Satomi , Togo Hideo
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
An Easy and General Protocol for Multicomponent Coupling Reactions of Aldehydes, Amides, and Dienophiles.
Authors: Struebing Dirk , Neumann Helfried , Jacobi von Wangelin Axel , Klaus Stefan , Huebner Sandra , Beller Matthias
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Catalytic Enantioselective Imino‐Reformatsky Reaction.
Authors: Cozzi Pier Giorgio
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Mannich‐Type Reaction in Water Employing a Dendritic Copper(II) Triflate Catalyst: A Positive Dendritic Effect on Chemical Yield.
Authors: Muraki Takahito , Fujita Ken‐ichi , Terakado Dai
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
CaCl2‐ or MgCl2‐Catalyzed Allylic Oxidations of Ionone‐Like Dienes.
Authors: Yang Min , Peng Qian‐Rong , Lan Jing‐Bo , Song Guang‐Fu , Xie Ru‐Gang
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Chemoselective Reduction of Aldehydes Using Decaborane in Aqueous Solution.
Authors: Lee Seung Hwan , Nam Mi Hye , Cho Min Young , Yoo Byung Woo , Rhee Hak June , Yoon Cheol Min
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Efficient Solvent‐Free Selective Monoalkylation of Arylacetonitriles with Mono‐, Bis‐, and Tris‐primary Alcohols Catalyzed by a Cp*Ir Complex.
Authors: Loefberg Christian , Grigg Ronald , Whittaker Mark A. , Keep Ann , Derrick Andrew
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
New Method of Synthesizing N‐Alkoxycarbonyl‐N‐arylamide with Triphosgene.
Authors: Zhou Yuhan , Gong Runjun , Miao Weirong
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Oxidative Coupling Reaction of N,N‐Dialkylanilines with Cerium(IV) Ammonium Nitrate in the Solid State.
Authors: Yang Xianghua , Xi Chanjuan , Jiang Yanfeng
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Polycyclic Heterocycles via a One‐Pot ortho Alkylation/Direct Heteroarylation Sequence.
Authors: Martins Andrew , Alberico Dino , Lautens Mark
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of 1‐Aryl‐1H‐indole Derivatives by Iodine‐Mediated Cyclization of 2‐(Arylamino)styrene Derivatives.
Authors: Kobayashi Kazuhiro , Miyamoto Kazuna , Yamase Tohru , Nakamura Daizo , Morikawa Osamu , Konishi Hisatoshi
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Rhodium‐Catalyzed Multicomponent‐Coupling Reactions Involving a Carborhodation—Cross‐Coupling Sequence.
Authors: Shintani Ryo , Yamagami Takafumi , Hayashi Tamio
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Stereoselective Preparation of 1,2,4‐Oxadiazole Derivatives Substituted by Pentafluorophenyl by 1,3‐Dipolar Cycloaddition Reaction.
Authors: Jiang Huiling , Zhao Jingwei , Han Xiaobing , Zhu Shizheng
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
An Easy and Straightforward Oxidative Rearrangement of 1,2‐Dialkoxy‐Substituted Olefins.
Authors: Fananas Francisco J. , Alonso Jorge , Rodriguez Felix , Borge Javier
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Rapid Divergent Synthesis of Highly Substituted δ‐Lactones.
Authors: Dieter R. Karl , Guo Fenghai
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Silica‐Gel‐Supported Aluminum Chloride: A Stable, Efficient, Selective, and Reusable Catalyst for Tetrahydropyranylation of Alcohols and Phenols.
Authors: Borujeni Kaveh Parvanak
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Stereochemical Control in the Reduction of 2‐Chromanols.
Authors: Li Kelin , Vanka Kumar , Thompson Ward H. , Tunge Jon A.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Rapid Synthesis of 4‐Benzyl‐4‐aminopiperidines by Addition of Grignard Reagents to N‐(1‐Boc‐Piperidine‐4‐ylidene)‐tert‐butanesulfinyl Imine.
Authors: Caldwell John J. , Collins Ian
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Efficient Synthesis of Pyridylacrylonitriles via the Heck Reaction.
Authors: Mai Kui , Wang Junbo , Hu Xianming
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of δ‐Thiolactams by the Aza‐Diels—Alder Reaction of in situ Generated Allenyltrimethylsilylthioketenes with Imines.
Authors: Aoyagi Shigenobu , Hakoishi Michiko , Suzuki Mariko , Nakanoya Yusuke , Shimada Kazuaki , Takikawa Yuji
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Practical Synthesis of New Chiral cis‐Phthalazinones with Potential for High Phosphodiesterase (PDE4) Inhibitory Activity.
Authors: Dang Tinh Van , Jin Chung Keun , Miyamoto Motoyuki , Ikee Yoshifumi , Masuda Takashi , Sano Shigeki , Shiro Motoo , Nagao Yoshimitsu
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Metal Triflimide as a Lewis Acid Catalyst for Biginelli Reactions in Water.
Authors: Suzuki Ichiro , Suzumura Yuko , Takeda Kei
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
One‐Pot, Three‐Component Synthesis of 2,3‐Dihydro‐4(1H)‐quinazolinones by Montmorillonite K‐10 as an Efficient and Reusable Catalyst.
Authors: Salehi Peyman , Dabiri Minoo , Baghbanzadeh Mostafa , Bahramnejad Mahboobeh
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
An Efficient Synthesis of Cyclic Urethanes from Boc‐Protected Amino Acids Through a Metal Triflate‐Catalyzed Intramolecular Diazocarbonyl Insertion Reaction.
Authors: Jung Jae‐Chul , Avery Mitchell A.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthetic Studies on the MARDi Cascade: Stereoselective Synthesis of Heterocyclic Seven‐Membered Rings.
Authors: Coquerel Yoann , Bensa David , Doutheau Alain , Rodriguez Jean
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Hexylselenol and Hexylselenides from Hexylthiol Involving Hexylthiolanium Salts.
Authors: Krief Alain , Dumont Willy , Robert Michael
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Enantioselective Syntheses of Tremulenediol A (I) and Tremulenolide A (II).
Authors: Ashfeld Brandon L. , Martin Stephen F.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Modified U‐4CR Reaction with 2‐Nitrobenzylamine as an Ammonia Equivalent.
Authors: Sung Kuangsen , Chen Fu‐Lin , Huang Pei‐Chun
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
First Synthesis of Argadin: A Nanomolar Inhibitor of Family‐18 Chitinases
Authors: Dixon Mark J. , Andersen Ole A. , van Aalten Daan M. F. , Eggleston Ian M.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A New One‐Pot Synthesis of Gb3 and isoGb3 Trisaccharide Analogues.
Authors: Wang Changning , Li Qin , Wang Haisheng , Zhang Li‐He , Ye Xin‐Shan
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Desymmetrization of Substituted 1,3‐Diketones: A Formal Synthesis of (+)‐Stemoamide.
Authors: Bogliotti Nicolas , Dalko Peter I. , Cossy Janine
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of 2‐Substituted 8‐Azabicyclo[3.2.1]octan‐3‐ones in Aqueous NaOH Solution of Low Concentration.
Authors: Jung Dai‐il , Song Ju‐hyun , Lee Do‐hun , Kim Yong‐hwan , Lee Yong‐gyun , Hahn Jung‐tai
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
In vitro Inhibitory Activity of Boropinic Acid Against Helicobacter pylori.
Authors: Epifano Francesco , Menghini Luigi , Pagiotti Rita , Angelini Paola , Genovese Salvatore , Curini Massimo
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Design and Development of Chemical Ontologies for Reaction Representation.
Authors: Sankar Punnaivanam , Aghila Gnanasekaran
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Heteroaryl‐substituted Semicarbazones: Synthesis and Anticonvulsant Activity of N‐(3‐Methylpyridin‐2‐yl)‐substituted Semicarbazones.
Authors: Mehta Shalini , Pavana Roheeth Kumar , Yogeeswari Perumal , Sriram Dharmarajan , Stables James
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A New Class of Compounds with Unusual Magnetic Behavior: Quasi‐One‐Dimensional Complex Oxides of the A3n+3mAn′B3m+nO9m+6n Family
Authors: Bazuev G. V.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Tungsten Compounds
Authors: Eglin Judith L.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Roads to New Guanidine Chemistry from 2‐Imidazolidinones Through 2‐Chloroamidinium Derivatives
Authors: Ishikawa Tsutomu
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Bidentate Ligands by Supramolecular Chemistry — The Future for Catalysis?
Authors: Sandee Albertus J. , Reek Joost N. H.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Calixarene‐ and Cavitand‐Based Capsules
Authors: Sliwa Wanda
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Enzymatic Aminolysis and Ammonolysis Processes in the Preparation of Chiral Nitrogenated Compounds
Authors: Gotor‐Fernandez Vicente , Gotor Vicente
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Biological Activity of Asp‐hemolysin as a Regulation Factor to Atherogenic Effect by Oxidized Low‐Density Lipoprotein
Authors: Kumagai Takeshi
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Bestimmung des Kontakt‐Wärmeübergangskoeffizienten aus transienten Temperaturmessungen
Authors: Fieberg C. , Kneer R.
Published: January 2007

Der thermische Kontaktwiderstand zwischen zwei angrenzenden Bauteilen ist in vielen technischen Anwendungen von großer Relevanz. Bisherige Untersuchungen des kontaktdruckabhängigen Wärmeübergangs beschränken sich auf niedrige Lasten im Bereich einiger Megapascal. Um die Berechnungssicherheit bei der Auslegung thermisch und mechanisch belasteter Bauteilverbindungen zu verbessern, sind genauere Kenntnisse zur Druckabhängigkeit des Kontaktwiderstandes notwendig.
Experimentelle Untersuchungen sowie 2D‐ und 3D‐Simulationen zum Stofftransport an Einzeltropfen mit Marangoni‐Konvektion
Authors: Wegener M. , Paschedag A. R. , Kraume M.
Published: January 2007

Die Überlagerung vieler, zum Teil gegensätzlicher Effekte am gesamten Stofftransport in technischen Apparaten macht es bisher unmöglich, den Anteil der Marangoni‐Konvektion am Stofftransport zu quantifizieren. In dieser Arbeit werden sowohl experimentelle als auch numerische Untersuchungen zum Stofftransport vorgestellt. Experimentell wird in einer Einzeltropfenkolonne der Frage nachgegangen, welchen Einfluss die Anfangskonzentration der Übergangskomponente auf die Stofftransportgeschwindigkeit hat. Die ermittelten Ergebnisse werden mit numerischen Simulationen verglichen.
Charakterisierung von autokatalytischen Zersetzungsreaktionen anhand von Messungen mit einem dynamischen Differenzkalorimeter
Authors: Fischer S. , Krahn G. , Reimer B.
Published: January 2007

Von Zersetzungsreaktionen, die nach einem autokatalytischen Reaktionstyp ablaufen, geht ein großes Gefahrenpotenzial aus. Die Induktionsphase von autokatalytischen Zersetzungsreaktionen ist schwer zu erkennen, weil kein oder nur ein geringer Temperaturanstieg zu beobachten ist. Dies stellt ein sicherheitstechnisches Problem dar, da die anlaufende Zersetzungsreaktion über den Temperaturanstieg nicht erfasst werden kann. Um den Zersetzungsverlauf beschreiben zu können, ist das Wissen um den Reaktionstyp notwendig. Das Ziel der durchgeführten Arbeiten besteht darin, durch mikrokalorische Untersuchungsmethoden Unterscheidungsmerkmale zwischen autokatalytischen Zersetzungsmechanismen und solchen n. Ordnung herauszuarbeiten.
Herausforderung Zukunft – Technischer Fortschritt und Globalisierung
Authors: Jischa M. F.
Published: January 2007

„Verantwortungsvoller Umgang mit Ressourcen”︁: So lautete der Titel der GVC/DECHEMA‐Jahrestagungen 2006. Im Folgenden soll das Thema in einen größeren Rahmen gestellt werden, bezeichnet als Herausforderung Zukunft. So lautet der Titel meines gleichnamigen Buches mit dem Untertitel Technischer Fortschritt und Globalisierung [1], dem die hier gezeigten Bilder und Tabellen entnommen sind. Interessant ist zunächst die Frage, warum und seit wann wir darüber nachdenken.
In Situ SAXS/WAXS of Zeolite Microwave Synthesis: NaY, NaA, and Beta Zeolites
Authors: Panzarella Bernard , Tompsett Geoffrey , Conner William C. , Jones Keith
Published: January 2007

A custom waveguide apparatus is constructed to study the microwave synthesis of zeolites by in situ small‐angle X‐ray scattering (SAXS) and wide‐angle X‐ray scattering (WAXS). The WR‐284 waveguide is used to heat precursor solutions using microwaves at a frequency of 2.45 GHz. The reaction vessels are designed to include sections of thin‐walled glass, which permit X‐rays to pass through the precursor solutions with minimal attenuation. Slots were machined into the waveguide to provide windows for X‐ray energy to enter and scatter from solutions during microwave heating. The synthesis of zeolites with conventional heating is also studied using X‐ray scattering in the same reactor. SAXS studies show that the crystallization of beta zeolite and NaY zeolite is preceded by a reorganization of nanosized particles in their precursor solutions or gels. The evolution of these particles during the nucleation and crystallization stages of zeolite formation depends on the properties of the precursor solution. The synthesis of NaA and NaX zeolites and sodalite from a single zeolite precursor is studied by microwave and conventional heating. Microwave heating shifts the selectivity of this synthesis in favor of NaA and NaX over sodalite; conventional heating leads to the formation of sodalite for synthesis from the same precursor. The use of microwave heating also led to a more rapid onset of NaA zeolite product crystallization compared to conventional heating. Pulsed and continuous microwave heating are compared for zeolite synthesis. The resulting rates of formation of the zeolite products, and the relative amounts of the products determined from the WAXS spectra, are similar when either pulsed or continuous microwave heating is applied in the reactor while maintaining the same synthesis temperature. The consequences of these results in terms of zeolite synthesis are discussed.
Circadian changes in Drosophila motor terminals
Authors: Mehnert Kerstin I. , Beramendi Ana , Elghazali Fahad , Negro Paolo , Kyriacou Charalambos P. , Cantera Rafael
Published: January 2007

In Drosophila melanogaster, as in most other higher organisms, a circadian clock controls the rhythmic distribution of rest/sleep and locomotor activity. Here we report that the morphology of Drosophila flight neuromuscular terminals changes between day and night, with a rhythm in synaptic bouton size that continues in constant darkness, but is abolished during aging. Furthermore, arrhythmic mutations in the clock genes timeless and period also disrupt this circadian rhythm. Finally, these clock mutants also have an opposing effect on the nonrhythmic phenotype of neuronal branching, with tim mutants showing a dramatic hyperbranching morphology and per mutants having fewer branches than wild‐type flies. These unexpected results reveal further circadian as well as nonclock related pleiotropic effects for these classic behavioral mutants. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007.
A switch in numb isoforms is a critical step in cortical development
Authors: Bani‐Yaghoub Mahmud , Kubu Chris J. , Cowling Rebecca , Rochira Jennifer , Nikopoulos George N. , Bellum Stephen , Verdi Joseph M.
Published: January 2007

Loss of numb function suggests that numb maintains progenitors in an undifferentiated state. Herein, we demonstrate that numb1 and numb3 are expressed in undifferentiated cortical progenitors, whereas numb2 and numb4 become prominent throughout differentiation. To further assess the role of different numb isoforms in cortical neural development, we first created a Numb‐null state with antisense morpholino, followed by the re‐expression of specific numb isoforms. The re‐expression of numb1 or numb3 resulted in a significant reduction of neural differentiation, correlating with an expansion of the cortical progenitor pool. In contrast, the expression of numb2 or numb4 resulted in a reduction of proliferating progenitors and a corresponding increase in mammalian achete‐scute homologue (MASH1) expression, concurrent with the appearance of the mitogen‐activated protein‐2–positive neurons. Of interest, the effect of numb isoforms on neural differentiation could not be directly related to Notch, because classic canonical Notch signaling assays failed to uncover any differences in the four isoforms to inhibit the Notch downstream events. This finding suggests that numb may have other signaling properties during neuronal differentiation in addition to augmenting notch signal strength. Developmental Dynamics 236:696–705, 2007. © 2007 Wiley‐Liss, Inc.
Synthesis of Novel Quinone–Amino Acid Hybrids via Cross‐Enyne Metathesis and Diels–Alder Reaction as Key Steps
Authors: Kotha Sambasivarao , Mandal Kalyaneswar , Banerjee Shaibal , Mobin Shaikh M.
Published: January 2007

A “Building Block Approach” for the synthesis of various quinone‐amino acid hybrids through ethylene cross‐enyne metathesis and Diels–Alder reaction as key steps is described. A library of comformationally constrained quinone‐based phenylalanine derivatives and dicarba analogs of cystine have been generated starting from a common precursor using Grubbs' catalysts. This methodology has also been extended for the synthesis of fullerene‐based dicarba analogs of cystine.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Efficient Synthesis of Benzofurans Utilizing [3,3]‐Sigmatropic Rearrangement Triggered by N‐Trifluoroacetylation of Oxime Ethers: Short Synthesis of Natural 2‐Arylbenzofurans
Authors: Takeda Norihiko , Miyata Okiko , Naito Takeaki
Published: January 2007

A new synthetic method for the preparation of benzofurans has been developed. The key step of this method is the [3,3]‐sigmatropic rearrangement of N‐trifluoroacetyl‐ene‐hydroxylamines, which was triggered by acylation of oxime ethers. TFAA has been proved to be the best reagent to induce [3,3]‐sigmatropic rearrangement for the synthesis of cyclic oracyclic dihydrobenzofurans. On the other hand, the TFAT‐DMAP system is found to be the most effective for constructing various benzofurans. Synthetic utility of this reaction is demonstrated by the short synthesis of natural benzofurans without protection of the hydroxy group. The synthesis of Stemofuran A was accomplished via condensation of ketones with aryloxyamine and subsequent reaction with TFAT‐DMAP in a four‐step synthesis with 72 % overall yield. Similarly, Eupomatenoid 6 and Coumestan were synthesized through the reaction of oxime ether with TFAT‐DMAP. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Enantio‐ and Diastereomerically Pure Decalins by Deslongchamps‐Type Annulation of Dienolates Containing a Chiral Lactone Substituent
Authors: Tricotet Thomas , Brückner Reinhard
Published: January 2007

A conceptionally novel 1,3‐asymmetric induction has been established. It controls the relative and absolute configuration of up to 5 stereocenters. They emerge from the anionic Diels–Alder reactions (“Deslongchamps annulations”) between oxocyclohexenecarboxylates 25, 29 and dienolates 26, 30. The latter contain a γ‐lactone. A Ph3Si–CH2 substituent therein controls the asymmetry of C–C bond formation with ds ≈ 10:1. Strangely, the preferred sense of attack of the dienophile is contrasteric. Cycloadduct 31 was processed by an unprecedented fluoride‐induced ambient‐temperature tandem fragmentation. It turned the lactone moiety into an allyl group and the β‐oxo (trimethylsilyl)ethyl ester into a ketone. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
The Thermal Transformations of Bicyclopropylidene and Methylenespiropentane Revisited
Authors: Schill Heiko , Kozhushkov Sergei I. , Walsh Robin , de Meijere Armin
Published: January 2007

The overall and the individual rate constants of the unimolecular thermal isomerization of methylenespiropentane (4) to 1,2‐ and 1,3‐dimethylenecyclobutanes (7 and 8) have been determined to be lg (k–4/s–1) = (13.78 ± 0.06) – (49.7 ± 0.2) kcal mol–1/RT·ln 10, lg (k7/s–1) = (13.03 ± 0.19) – (48.0 ± 0.6) kcal mol–1/RT·ln 10 and lg (k8/s–1) = (14.15 ± 0.19) – (52.4 ± 0.5) kcal mol–1/RT·ln 10, respectively. The activation energies are significantly lower than that for the rearrangement of the parent spiropentane.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Modeling and simulation of IEF in 2‐D microgeometries
Authors: Shim Jaesool , Dutta Prashanta , Ivory Cornelius F.
Published: January 2007

A 2‐D finite‐volume model is developed to simulate nonlinear IEF in complex microgeometries. This mathematical model is formulated based on the mass conservation and ionic dissociation relations of amphoteric macromolecules, charge conservation, and the electroneutrality condition. Based on the 2‐D model, three different separation cases are studied: an IPG in a planar channel, an ampholyte‐based pH gradient in a planar channel, and an ampholyte‐based pH gradient in a contraction–expansion channel. In the IPG case, cacodylic acid (pK1 = 6.21) and Tris (pK1 = 8.3) are used as the acid and base, respectively, to validate the 2‐D IEF model. In the ampholyte‐based pH gradient cases, IEF is performed in the pH range, 6.21–8.3 using 10 ampholytes in the planar channel and 20 ampholytes in the contraction–expansion channel. The numerical results reveal different focusing efficiencies and resolution in the narrow and wide sections of the contraction–expansion channel. To explain this, the expressions for separation resolution and peak concentrations of separands in the contraction–expansion channel are presented in terms of the channel shape factor. In a 2‐D planar channel, a focused band remains straight all the time. However, in a contraction–expansion channel, initially straight bands take on a crescent profile as they pass through the trapezoidal sections joining the contraction and expansion sections.
Theory of band broadening during cycling temperature capillary electrophoresis
Authors: Laachi Nabil , Dorfman Kevin D.
Published: January 2007

A two‐state transport model is presented for cycling temperature CE. In this high‐throughput method of mutation detection, the temperature oscillates in time, causing the DNA to periodically transit between an annealed state and a partially melted (denatured) state. The change in state alters the electrophoretic mobility, and the presence of a mutation changes the temperature dependence of the denaturing/annealing kinetics. Asymptotic formulae for the mean velocity and effective diffusivity (dispersivity) of the DNA are computed by a multiple‐time scales scheme in the limit where the DNA have experienced many temperature cycles before reaching the detector. Explicit analytical results are presented for the case where the temperature cycle consists of one interval with irreversible annealing, followed by a second interval with an infinitely fast, irreversible denaturation. The lag in the annealing leads to a reduction in the mean velocity and an enhanced dispersion compared to the idealized case where the DNA respond instantaneously to the changes in temperature, with the dispersion scaling quadratically with the electric field. The predicted plate height scales linearly with the electric field, and the optimal separation resolution is predicted for moderate values of the cycle frequency that allow the DNA to relax during each temperature oscillation.
Fluorescence in situ hybridization is necessary to detect an association between chromosome aberrations and polycyclic aromatic hydrocarbon exposure in utero and reveals nonrandom chromosome involvement
Authors: Bocskay Kirsti A. , Orjuela Manuela A. , Tang Deliang , Liu Xinhua , Warburton Dorothy , Perera Frederica P.
Published: January 2007

Chromosome aberrations are associated with environmental exposures in infants and children. Recently we reported that prenatal exposure to airborne polycyclic aromatic hydrocarbons (PAHs) was significantly (P < 0.01) associated with stable aberration frequencies in cord blood from a subset of 60 newborns from the Columbia Center for Children's Environmental Health Prospective Cohort Study (Bocskay K et al. [ 2005]: Cancer Epidemiol Biomarkers Prev 14:506–511). To determine whether the environmental exposures may be targeting specific chromosomes and to compare various methods for measuring chromosome aberrations, we further evaluated this same subset of subjects composed of African‐American and Dominican nonsmoking mother–newborn pairs residing in low‐income neighborhoods of New York City, and exposed to varying levels of airborne PAHs. Chromosome aberrations were measured in cord blood lymphocytes, both by whole chromosome probe (WCP) fluorescence in situ hybridization (FISH) and traditional Giemsa‐staining. Prenatal exposures were assessed by personal air monitoring. Breaks in chromosomes 1–6, as detected by WCP FISH, were nonrandomly distributed, underscoring the importance of appropriate chromosome probe selection to capture cytogenetic damage in response to exposure. FISH for stable aberrations was found to be a more sensitive method for detecting aberration frequencies associated with environmental exposures, when compared with FISH for unstable aberrations or Giemsa‐staining for aberrations. Together, these results suggest that PAHs may be targeting specific chromosomes and highlight the importance of using the more sensitive detection methods to assess risk in populations with low levels of exposure. Environ. Mol. Mutagen., 2007. © 2007 Wiley‐Liss, Inc.
Malpractice litigation and medical costs in Mississippi
Authors: Roberts Brandon , Hoch Irving
Published: January 2007

This paper examines the impact of varying levels of malpractice litigation on area medical costs. Using a fixed‐effects model and Medicare Part B as the dependent variable, the results indicate that per enrollee medical expenditures are positively related to the incidence of medical malpractice lawsuits. The higher cost is presumed to be attributable to ‘defensive practices’ by area physicians based on varying degrees of perceived risk. The results suggest the addition to cost is substantial, possibly adding up to 25% in some jurisdictions with the impact exceeding annual dollar amounts of malpractice judgments and settlements. Copyright © 2007 John Wiley & Sons, Ltd.
Fixation of mandibular osteotomies: Comparison of locking and nonlocking hardware
Authors: Kim Young , Smith Jesse , Sercarz Joel A. , Head Christian , Abemayor Elliot , Blackwell Keith E.
Published: January 2007

Background.

The outcome of patients undergoing rigid plate fixation of symphyseal mandibular osteotomies for exposure, resection, and reconstruction of tumors in the oral cavity or oropharynx was analyzed to determine the impact of hardware selection on complications.

Methods.

Forty‐five patients underwent titanium plate rigid internal fixation of mandibular osteotomies during cancer resection and free flap reconstruction at an academic medical center. The incidence of hardware‐related complications and mandibular nonunion was compared in patients receiving either locking hardware or nonlocking hardware.

Results.

The incidence of osteotomy‐related complications in patients with an inferior border nonlocking mandibular fracture plate was 21%. In the patients with locking hardware or an inferior border nonlocking mandibular fracture plate combined with a tension band, there were no hardware‐related complications and no mandibular nonunions. This difference was statistically significant (χ2 = 6.01, p < .05).

Conclusions.

Locking mandibular reconstruction plates are associated with fewer complications than inferior border nonlocking mandibular fracture plates for rigid fixation of mandibular osteotomies in patients undergoing resection of head and neck cancer. © 2007 Wiley Periodicals, Inc. Head Neck, 2007
Pleomorphic adenoma of the parotid gland: Histopathologic analysis of the capsular characteristics of 218 tumors
Authors: Zbären Peter , Stauffer Edouard
Published: January 2007

Background.

Histopathologic features of the capsule may have an impact on the recurrence rate of pleomorphic adenomas.

Methods.

Retrospective (n = 154) and prospective (n = 64) histologic analysis of the capsular characteristics such as incompleteness, tumor penetration, pseudopodia, and satellite tumors of 218 pleomorphic adenomas.

Results.

In 160 of the 218 (73%) pleomorphic adenomas, 1 or more capsular characteristics such as incomplete capsule (33%), capsule penetration (26%), pseudopodia (40%), and satellite nodules (13%) were detected. Incomplete capsule and satellite tumors were most frequently seen in the stroma‐rich (myxoid) subtype. Capsular penetration and pseudopodia were significantly more common in the prospective group than in the retrospective group (p < .05/<.05).

Conclusion.

Pseudopodia and satellite tumors were more common than reported in the literature. If left in the surrounding salivary gland tissue at surgery, they can lead to recurrences of pleomorphic adenomas of the parotid gland. © 2007 Wiley Periodicals, Inc. Head Neck, 2007
Effects of cidofovir on a novel cell‐based test system for recurrent respiratory papillomatosis
Authors: Donne Adam J. , Hampson Lynne , He Xiao T. , Rothera Michael P. , Homer Jarrod J. , Hampson Ian N.
Published: January 2007

Background.

Cidofovir has been reported to have activity against human papillomavirus (HPV) type 16, but no laboratory studies have been performed on HPV type 6, the main cause of recurrent respiratory papillomatosis (RRP).

Methods.

HPV6b E6 cDNA‐based C33A (non‐HPV cervical carcinoma) cell line was produced. Two different doses of cidofovir were applied to parent C33A, C33AT6E6, and C33AT16E6 (HPV 16). Growth and flow cytometry analysis were performed.

Results.

Polymerase chain reaction confirmed HPV6 E6 expression in C33AT6E6 cells. High‐dose cidofovir was found to be toxic to all cell lines. Low‐dose exposure was found to be toxic to C33AT16E6 cells at 3 days, whereas C33A and C33AT6E6 showed minimal toxicity at 6 days and earlier recovery following drug withdrawal.

Conclusions.

Cidofovir showed nonspecific toxicity against all 3 cell lines tested. HPV16 E6 expressing cells were more sensitive than parent or HPV6 E6 expressing cells. Cidofovir has no selective advantage for the RRP‐related HPV6 E6 expressing cell line. © 2007 Wiley Periodicals, Inc. Head Neck, 2007
Application of multivariate statistical procedures to the hydrochemical study of a coastal aquifer: an example from Crete, Greece
Authors: Papatheodorou G. , Lambrakis N. , Panagopoulos G.
Published: January 2007

A variety of multivariate statistical procedures were applied to three separate sets of quantitative analytical data from a coastal aquifer located in Malia, Crete (Greece), in order to identify the major hydrochemical processes affecting the groundwater quality and to investigate the evolution of groundwater composition in three different sampling periods. Two of them were carried out on October 2001 and September 2002 at the end of the dry season and the third on April 2002 at the end of the wet period. Two factors were found that explained major hydrochemical processes in the aquifer. These factors reveal the existence of an intensive intrusion of seawater and mechanisms of nitrate contamination of groundwater. Bivariate plots of the scores of the two main factors showed that the seawater intrusion and nitrate pollution processes are maintained through three surveys and that the process of nitrate pollution increases from the first to the second dry survey. Q‐mode factor analysis and discriminant analysis of the three sampling periods clearly showed a seasonal variation of the whole chemistry of groundwater samples. This seasonal variation can be attributed to the freshwater recharge and seawater intrusion that affect the groundwater quality of the Malia aquifer. The results of trend surface analysis are in agreement with those of factor analysis. Moreover, the fourth‐order trend surfaces of EC, Cl− and NO3− showed that the salinization process is more intensive during the first dry period and the spatial variation of NO3− maxima plumes are strongly affected by the flow regime of the Malia aquifer. Copyright © 2007 John Wiley & Sons, Ltd.
What if the UK or Sweden had joined the euro in 1999? An empirical evaluation using a Global VAR
Authors: Hashem Pesaran M. , Vanessa Smith L. , Smith Ron P.
Published: January 2007

This paper attempts to provide a conceptual framework for the analysis of counterfactual scenarios using macroeconometric models. As an application we consider UK entry to the euro. Entry involves a long‐term commitment to restrict UK nominal exchange rates and interest rates to be the same as those of the euro area. We derive conditional probability distributions for the difference between the future realizations of variables of interest (e.g. UK and euro area output and prices) subject to UK entry restrictions being fully met over a given period and the alternative realizations without the restrictions. The robustness of the results can be evaluated by also conditioning on variables deemed to be invariant to UK entry, such as oil or US equity prices. Economic interdependence means that such policy evaluation must take account of international linkages and common factors that drive fluctuations across economies. In this paper this is accomplished using the Global VAR recently developed by Dees et al. (J. Appl. Econometrics, 2007, forthcoming). The paper briefly describes the GVAR which has been estimated for 25 countries and the euro area over the period 1979–2003. It reports probability estimates that output will be higher and prices lower in the UK and the euro area as a result of entry. It examines the sensitivity of these results to a variety of assumptions about when and how the UK entered and the observed global shocks and compares them with the effects of Swedish entry. Copyright © 2007 John Wiley & Sons, Ltd.
Differential effects of uniaxial and biaxial strain on U937 macrophage‐like cell morphology: Influence of extracellular matrix type proteins
Authors: Matheson Loren A. , Maksym Geoffrey N. , Santerre J. Paul , Labow Rosalind S.
Published: January 2007

Tissue engineering concepts have expanded in the last decade to consider the importance of biochemical signaling from extracellular matrix (ECM) proteins adhered to substrates such as polymeric and ceramic scaffolds. This study investigated combined ECM/mechanical factors on the key signaling cells (macrophages) for wound healing, since previously, mechanical strain and ECM proteins have only been considered separately for their effects on macrophage morphology. Human U937 macrophage‐like cells were cultured on a model elastomeric membrane, coated with either collagen type I or poly‐RGD peptide (ProNectin®). The cells were subjected to cyclic uniform uniaxial or nonuniform biaxial strain with the Flexercell™ Tension Plus system to simulate strains that various soft tissue implants may undergo during the critical tissue–implant integration period. The surface coatings affected total cellular protein, which was significantly higher in cells on collagen than ProNectin® coated surfaces after biaxial, but not uniaxial strain, whereas ProNectin® coated surfaces caused a decrease in DNA following uniaxial, but not biaxial strain. Adding the protein coatings that relate to the wound healing process during tissue regeneration, elicited effects specific to the strain type imposed. The combination of these parameters caused changes in U937 macrophage‐like cells that should be considered in the outcome of the desired performance in the tissue–material constructs. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Properties and molecular evolution of human GLUD2 (neural and testicular tissue‐specific) glutamate dehydrogenase
Authors: Kanavouras Konstantinos , Mastorodemos Vasileios , Borompokas Nikolas , Spanaki Cleanthe , Plaitakis Andreas
Published: January 2007

Glutamate dehydrogenase (GDH) is an enzyme central to the metabolism of glutamate that also plays a role in cellular energetics. In the human, GDH exists in a housekeeping isoenzyme (hGDH1) encoded by the GLUD1 gene and a neural and testicular tissue‐specific isoform (hGDH2) encoded by the GLUD2 gene. There is evolutionary evidence that the GLUD1 was retroposed to the X chromosome in the ape ancestor (<23 million years ago), where it gave rise to GLUD2 through random mutations and directional selection. In the human, the two mature GDH isoproteins are highly homologous, differing in only 16 of their 505 amino acid residues. Functional analyses of highly purified recombinant wild‐type hGDH2 revealed that this adaptive evolution dissociated the enzyme from GTP control, permitted regulation almost entirely by ADP and/or L‐leucine, and fine‐tuned its activity to the relatively low cellular pH that occurs in synaptic astrocytes during excitatory transmission. Study of structure‐function relationships, using site‐directed mutagenesis of GLUD1 at single sites differing from GLUD2, showed that the Arg443Ser and the Gly456Ala change reproduced some, but not all, of the properties of hGDH2. In addition, we created a double hGDH1 mutant that had both Arg443Ser and Gly456Ala in the same polypeptide chain. Functional analyses revealed that the doubly mutated enzyme did not acquire all the characteristics of the wild‐type hGDH2. Hence, additional amino acid changes, acting in concert with Arg443Ser and Gly456Ala, ought to be responsible the unique properties of the brain‐specific human isoenzyme. © 2007 Wiley‐Liss, Inc.
Tephrabase: tephrochronology and the development of a centralised European database
Authors: Newton Anthony J. , Dugmore Andrew J. , Gittings Bruce M.
Published: January 2007

Tephrabase was launched on the World Wide Web in 1995 as a tool for tephrochronological research. In order to facilitate the identification, correlation and dating of tephra deposits, this database may be interrogated through multiple routes, including by source volcano, date, location, and tephra chemistry; datasets include stratigraphy, geochemistry, chronology and spatial information. Currently all the European data refer to Late Quaternary Icelandic‐sourced tephras, post‐12 k yr BP. The sites (62) where the tephra deposits are found include Iceland, the United Kingdom, Ireland, the Faroe Islands, Sweden and Russia. In addition, there are also data on tephra layers in central Mexico. Use of Tephrabase highlights the importance of selected geochemical data, but this has to be used with care as major element characteristics alone do not always produce unique definitions for single tephra deposits. For the most accurate results multiple criteria must be used. Tephrabase can be found at http://www.tephrabase.org. Copyright © 2007 John Wiley & Sons, Ltd.
The case for significant numbers of extraterrestrial impacts through the late Holocene
Authors: Baillie Mike
Published: January 2007

When astronomers tell us that there should have been numerous impacts from space during the last five millennia, when impact craters exist on land and more impacts can be assumed over the oceans, why are historians, archaeologists and palaeoecologists not diligently seeking evidence for these impacts, and their effects? This article reviews just some of the relevant evidence for impacts. In turn this suggests that ablation material, background material from space, and micro‐tektites, should all be present in ocean cores, ice cores, peat, and lake sediments. It seems that almost no efforts have been made to find evidence that might link to the known crater fields, or to identify and date periods of enhanced cosmic activity. The question must be, why? Copyright © 2007 John Wiley & Sons, Ltd.
Competing kinetic pathways in the bromine addition to allylic ethers in 1,2‐dichloroethane: Opposite temperature effects
Authors: Cecchi Alessandro , Bartalucci Giuditta , Chiappe Cinzia , Bianchini Roberto
Published: January 2007

The kinetics of the electrophilic bromination of three allylic ethers in a nonprotic solvent, 1,2‐dichloroethane, has been investigated. Two of them followed a prevalent second‐order pathway, while the third one exhibited a classical, clean third order. The second‐order pathway in the first two olefins is attributed to electrophilic assistance of the ethereal oxygen to the attacking bromine molecule. In the molecular bromination of 2,4‐cis‐dimethyl‐8‐oxabicyclo[3.2.1]‐6‐octen‐3‐cis‐ol, opposite temperature dependences were found for the two different kinetic pathways. An exoergonic process for the second‐order reaction was explained by the lesser stability of the bromiranium–bromide ionic intermediate, compared to the bromiranium–tribromide in the third‐order profile. © 2007 Wiley Periodicals, Inc. 39: 197–203, 2007