bluuebunny/crossref_metadata_2025 huggingface dataset:
Instruments of cognition: Use of citations and Web links in online teaching materials
Authors: Coleman Anita
Published: December 2004

Use of citations and Web links embedded in online teaching materials was studied for an undergraduate course. The undergraduate students enrolled in Geographic Information Science for Geography and Regional Development used Web links more often than citations, but clearly did not see them as key to enhancing learning. Current conventions for citing and linking tend to make citations and links invisible. There is some evidence that citations and Web links categorized and highlighted in terms of their importance and function to be served may help student learning in interdisciplinary domains.
Effect in rats of simultaneous prenatal exposure to ochratoxin A and aflatoxin B1. II. Histopathological features of teratological anomalies induced in fetuses
Authors: Wangikar P.B. , Dwivedi P. , Sharma A.K. , Sinha Neeraj
Published: December 2004

The histopathological features of various abnormalities induced by different doses of ochratoxin A (OA), aflatoxin B1 (AFB1), and their combination in rat fetuses were studied. The pregnant Wistar rats were orally treated during 6–15 gestation days with different doses of OA (0.125, 0.25, 0.50, 0.75 mg/kg), AFB1 (0.125, 0.25, 0.50, 1.00 mg/kg), and their combination (0.125+0.125, 0.25+0.50, 0.50+0.25 mg/kg). The fetal sections passing through liver, kidney, brain, heart, and eyes were selected from the fetuses given visceral examination representing each litter. The selected sections were processed for paraffin embedding, stained with H and E, and examined by light microscopy. The histological examination of the fetal organs revealed that OA, AFB1, and their combination treatments caused variable changes in internal organs. In the case of OA, the incidence of pathological lesions liver, kidney, brain, and eye lesions was high, whereas in AFB1treatment, liver, brain, kidney, and heart were affected. The incidence of heart lesions, especially valvular defects, increased in the combination groups. Bile duct proliferation/new bile duct formation, defective ossification of cranial bones, exposure of the brain to the exterior, hypoplasia of cerebellum, and retinal defects observed in OA treatment and spinal cord defects in addition to liver, kidney, and brain changes observed in AFB1 were less severe in the combination groups. The present study indicates that the occurrence of brain, kidney, and liver lesions in combination treatment was less than in either individual treatment suggesting antagonism of OA‐induced teratogenic effects by AFB1. The indication of subtle lesions due to an interference with normal development and arrest of differentiation in various internal organs observed in the present study suggests that microscopic examination of the tissues can provide additional useful information to a developmental toxicity study. Birth Defects Res B 71:352–358, 2004. © 2004 Wiley‐Liss, Inc.
Effects of human and murine antisense oligonucleotide inhibitors of ICAM‐1 on reproductive performance, fetal development, and post‐natal development in mice
Authors: Henry Scott P. , Denny Kevin H. , Templin Mike V. , Yu Rosie Z. , Levin Arthur A.
Published: December 2004

The potential for reproductive toxicity of an antisense oligonucleotide designed to inhibit ICAM‐1 was evaluated as part of the safety assessment for this compound. Since antisense compounds are often specific to the species in which they are intended to work, both the human and murine active ICAM‐1 inhibitors were tested (ISIS 2302 and ISIS 3082, respectively). Male and female mice were treated prior to cohabitation, through cohabitation, gestation, delivery, and weaning. Mice were treated with 0, 3, 6, and 12 mg/kg ISIS 2302 or ISIS 3082 by daily i.v. injection. Reproductive indices evaluated included estrus cycling, sperm count and motility, fertility, litter parameters, fetal development, delivery, fetal body weight, lactation, and weaning. Behavioral assessment and reproductive capacity of the F1 generation mice was assessed on selected animals. Concentrations of oligonucleotide in selected maternal target organs, placenta, fetal tissues, and expressed milk were also measured. There were no changes in reproductive performance, litter parameters, fetal development, or postnatal development in mice treated with either ISIS 2302 or ISIS 3082. Maternal liver and kidney contained dose‐dependent concentrations of oligonucleotide, but there was relatively little or no oligonucleotide measured in placenta, fetal tissues, or expressed milk. Neither the human nor murine‐specific antisense inhibitor of ICAM‐1 produced any reproductive toxicity in mice, and exposure of fetus or pups was negligible. Birth Defects Res B 71:359–367, 2004. © 2004 Wiley‐Liss, Inc.
Developmental toxicity evaluation of trimethylolpropane caprylate caprate in Sprague‐Dawley rats
Authors: Azuka Charles , Daston George P.
Published: December 2004

The developmental toxicity potential of trimethylolpropane caprylate caproate (TMPCC, CAS no. 11138‐60‐6) was evaluated in rats. Sprague‐Dawley rats were administered TMPCC in a corn oil suspension dermally at dose levels of 0, 200, 600, or 2,000 mg/kg/day on gestation days (GD) 6–15 (sperm positive day=GD 0). Caesarean sections were performed on GD 20 and fetuses were evaluated for viability, growth, and external, visceral, and skeletal abnormalities. Each group consisted of 25 females, with at least 22 per group being pregnant. The two highest dose levels caused some local irritation at the site of application, but no decreases in maternal weight gain. There were no differences from control in any of the developmental parameters measured, including embryo/fetal viability, fetal weight, malformations, or variations. TMPCC did not cause any developmental toxicity in the Sprague‐Dawley rat at dermal dosages up to 2,000 mg/kg/day. Birth Defects Res B 71:374–379, 2004. © 2004 Wiley‐Liss, Inc.
Developmental toxicity of artesunate and an artesunate combination in the rat and rabbit
Authors: Clark Robert L. , White Tacey E.K. , A. Clode Sally , Gaunt Ian , Winstanley Peter , Ward Stephen Andrew
Published: December 2004

The artemisinins are playing an increasingly important role in treating multidrug‐resistant malaria. The artemisinin, artesunate, is currently in use in Southeast Asia and is advocated for use in Africa. In these areas, more than one million people die of malaria each year, with the highest mortality occurring in children and pregnant women. To test the developmental toxicity in ICH‐compliant animal studies, embryofetal development studies were conducted in rats and rabbits treated with artesunate alone or a three‐drug combination (CDA) consisting of chlorproguanil hydrochloride, Dapsone, and artesunate in the ratio 1.00:1.25:2.00. Developmental toxicity seen with CDA could be attributed to the administered dose of artesunate. The hallmark effect of artesunate exposure was a dramatic induction of embryo loss, apparent as abortions in rabbits and resorptions in both rats and rabbits. In addition, low incidences of cardiovascular malformations and a syndrome of skeletal defects were induced at or close to embryolethal doses of artesunate in both rats and rabbits. The cardiovascular malformations consisted of ventricular septal and vessel defects. The skeletal syndrome consisted of shortened and/or bent long bones and scapulae, misshapen ribs, cleft sternebrae, and incompletely ossified pelvic bones. These developmental effects were observed largely in the absence of any apparent maternal toxicity. The no or low adverse effect levels were in the range of 5 to 7 mg/kg/day artesunate. Encouragingly, no adverse drug‐related developmental effects have been observed in a limited number of pregnant women (more than 100 first trimester and 600 second and third trimester) treated with artemisinins, primarily artesunate. Investigations of the mechanism of developmental toxicity are ongoing to attempt to determine whether rats and rabbits are more sensitive to artemisinins than humans. Birth Defects Res B 71:380–394, 2004. © 2004 Wiley‐Liss, Inc.
Child protection at the community level
Authors: Jack Gordon
Published: December 2004

In the UK, individual and family‐level interpretations of child protection have historically taken precedence over community‐level interpretations, despite repeated attempts to balance these two approaches. With the publication of the Green Paper Every Child Matters (Department for Education and Skills, 2003) and the development of Children's Trusts, there is yet another opportunity to ensure that the community‐level aspect of child protection is properly recognized and resourced. This is particularly important within the UK because of the large structural inequalities that exist in the distribution of income and other resources and services. As a result of the very close associations between these inequalities and health and welfare outcomes, large numbers of children are adversely affected in ways that are generally unrecognized by the present child protection system. Evidence about the role of parents' social support networks and the social capital of communities in promoting children's welfare and protecting them from signiﬁcant harm is considered. The potential of strategies designed to strengthen the capacity of disadvantaged families and communities to provide positive environments for children is also reviewed. Copyright © 2004 John Wiley & Sons, Ltd.
Molecular and Cellular Basis of Human Olfaction
Authors: Hatt Hanns
Published: December 2004

The human olfactory systems recognize and discriminate a large number of different odorant molecules. The detection of chemically distinct odorants begins with the binding of an odorant ligand to a specific receptor protein in the ciliary membrane of olfactory neurons. To address the problem of olfactory perception at a molecular level, we have cloned, functionally expressed, and characterized some of the human olfactory receptors from chromosome 17. Our results show that a receptor protein is capable of recognizing the particular chemical substructure of an odor molecule and, therefore, is able to respond only to odorants that have a defined molecular structure. These findings represent the beginning of the molecular understanding of odorant recognition in humans. In the future, this knowledge could be used for the design of synthetic ideal receptors for specific odors (biosensors), or the perfect odor molecule for a given receptor.
Scent through the Looking Glass
Authors: Sell Charles S.
Published: December 2004

In 1896, Tiemann first raised the question of whether or not enantiomers might exhibit different odors. The classic work of von Braun should have settled the issue in 1927 but the debate continued for decades, often rather acrimoniously. Various factors such as purity of samples and subjectivity of odors provided the confusion necessary to perpetuate disagreement. Nowadays, we have enough good‐quality data to know that sometimes, absolute configuration affects odor perception and sometimes it does not. We are, therefore, left with some interesting academic and commercial questions to be addressed.
New Alicyclic Musks: The Fourth Generation of Musk Odorants
Authors: Eh Marcus
Published: December 2004

Musk odorants are one of the most important classes of fragrances in perfumery because they impart sensuality to perfume‐oil compositions. Among the three well‐known classes of musks, a new and very exciting generation of musk odorants, the so‐called alicyclic musks, was discovered recently, of which Helvetolide® (2) and Romandolide® (3) are the most popular representatives so far. To find new, structurally related alicyclic musks, we have synthesized a library of 114 unique alicyclic molecules with modified cyclohexyl moieties. The olfactory properties of all compounds were evaluated to identify the structural requirements to be met for a musk odorant.
The Search for New Fragrance Ingredients for Functional Perfumery
Authors: Narula Anubhav P. S.
Published: December 2004

Functional perfumery is an integral part of the fragrance business. It demands that the ingredients chosen for compounding withstand the aggressive nature of some of the bases used for soaps, detergents, softeners, bleach, and personal‐care products. The synthetic efforts in this area reported in this short personal account, presented in a talk at the RSC/SCI conference Flavours & Fragrances 2004 (Manchester), have resulted in the discovery of the two new proprietary molecules Fleuranil® (5/6) and Khusinil® (7), which fulfill the criteria of functional perfumery. The structure–odor relationships of several analogs of Fleuranil® and Khusinil® prepared in the course of these investigations are also presented.
Studies on the Volatile Compounds of Roasted Spotted Shrimp
Authors: Tachihara Toru , Ishizaki Susumu , Ishikawa Masashi , Kitahara Takeshi
Published: December 2004

The aroma of spotted shrimp (Sergia lucence Hansen) was analyzed upon roasting to determine the components that constitute the characteristic roasted shrimp flavor. Our analyses resulted in the identification of ca. 200 volatiles, including high‐impact sulfur and nitrogen compounds. In addition, we synthesized all possible stereoisomers of the pyrrolidine derivatives 1 and 4, and of the imine derivatives 16 and 18–20, which are very characteristic for the aroma. The odor evaluation of these chemicals revealed distinct differences, each possessing different aroma characteristics.
Fun with Furans
Authors: Rowe David
Published: December 2004

The aromatic furan ring is found in a wide range of aroma chemicals, especially those produced by the Maillard reaction. They include both low‐odor materials such as furfural and high‐impact materials such as 2‐methylfuran‐3‐thiol. Among the most important are the hydroxyfuranones, especially 4‐hydroxy‐2,5‐dimethylfuran‐3(2H)‐one (HDMF, 7), which is a material of unusual reactivity. This contrasts with the inert character of its isomer sotolone. Furans are also found as trace components where they can either contribute a desirable character or an off‐note depending on context.
Photoelectron Spectroscopy of Free Polyoxoanions Mo6O2‐19 and W6O2‐19 in the Gas Phase.
Authors: Yang Xin , Waters Tom , Wang Xue‐Bin , O'Hair Richard A. J. , Wedd Anthony G. , Li Jun , Dixon David A. , Wang Lai‐Sheng
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Praseodymium Diiodide, PrI2, Revisited by Synthesis, Structure Determination and Theory.
Authors: Gerlitzki Niels , Meyer Gerd , Mudring Anja‐Verena , Corbett John D.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Crystal and Species Engineering with Semi‐Flexible Nitrogen Containing Organic Cations: Generation of [H13O6]+ Ions with the Unfavored Unbranched Topology by Enclosing Hydrochloric Acid in a Porous Inorganic‐Organic Hybrid Material.
Authors: Graf J. , Frank W.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Crystallization of Charge Holes in the Spin Ladder of Sr14Cu24O41.
Authors: Abbamonte P. , Blumberg G. , Rusydi A. , Gozar A. , Evans P. G. , Siegrist T. , Venema L. , Eisaki H. , Isaacs E. D. , Sawatzky G. A.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Four New Thioantimonates(III) with the General Formula [TM(ten)]Sb4S7 (TM: Mn, Fe, Co, Zn) with the Transition Metal as Part of a Thioantimonate(III) Network Synthesized under Solvothermal Conditions and Tuning of the Optical Band Gap by the Transition Metal Cation.
Authors: Schaefer Michael , Staehler Ralph , Kiebach Wolff‐Ragnar , Naether Christian , Bensch Wolfgang
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Copper‐Catalyzed Enantioselective Allylic Substitution by MeMgX.
Authors: Tissot‐Croset Karine , Alexakis Alexandre
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Bidentate NHC‐Based Chiral Ligands for Efficient Cu‐Catalyzed Enantioselective Allylic Alkylations: Structure and Activity of an Air‐Stable Chiral Cu Complex.
Authors: Larsen Andrew O. , Leu Wenhao , Oberhuber Christina Nieto , Campbell John E. , Hoveyda Amir H.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Chiral Thiazoline Ligands: Application in Pd‐Catalyzed Allylic Substitution.
Authors: Abrunhosa Isabelle , Delain‐Bioton Lise , Gaumont Annie‐Claude , Gulea Mihaela , Masson Serge
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Rhodium‐Catalyzed Asymmetric 1,4‐Addition of Alkenylsilanes Generated by Hydrosilylation of Alkynes: A One‐Pot Procedure Where a Rhodium/(S)‐Binap Complex Catalyzes the Two Successive Reactions.
Authors: Otomaru Yusuke , Hayashi Tamio
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
An Innovative Strategy for Electrochemically‐Promoted Addition Reactions.
Authors: Palombi Laura , Feroci Marta , Orsini Monica , Inesi Achille
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Palladium(II)‐Catalyzed Isomerization‐Claisen Rearrangement of 2‐Alkoxy Diallyl Ethers.
Authors: Nevado Cristina , Echavarren Antonio M.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
InCl3/SiO2‐Catalyzed α‐Amination of 1,3‐Dicarbonyl Compounds under Microwave Irradiation.
Authors: Yadav J. S. , Reddy B. V. Subba , Venugopal Ch. , Padmavani B.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
(Bu3Sn)2—TBAF: A New Combination Reagent for the Reduction and Deuteration of Aryl Bromides and Iodides.
Authors: Harrowven David C. , Guy Ian L. , Nunn Michael I. T.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Highly Regioselective Ring Opening of Epoxides Using NaN3: A Short and Efficient Synthesis of (‐)‐Cytoxazone.
Authors: Boruwa Joshodeep , Borah Jagat C. , Kalita Biswajit , Barua Nabin C.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Efficient Aldehyde Olefination Reactions Catalyzed by an Iron Porphyrin Complex in an Ionic Liquid.
Authors: Sun Wei , Kuehn Fritz E.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Diethyl Cyclopropylidenemalonate: Facile Preparation, Generation in situ, and Various Transformations.
Authors: de Meijere Armin , Kostikov Rafael R. , Savchenko Andrei I. , Kozhushkov Sergei I.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
CuI‐Catalyzed Coupling Reaction of Aryl Halides with Terminal Alkynes in the Absence of Palladium and Phosphine.
Authors: Ma Dawei , Liu Feng
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
An Efficient and Green Protocol for the Preparation of Cycloalkanols: A Practical Synthesis of Venlafaxine.
Authors: Chavan Subhash P. , Khobragade Dushant A. , Kamat Subhash K. , Sivadasan Latha , Balakrishnan Kamalam , Ravindranathan T. , Gurjar Mukund K. , Kalkote Uttam R.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
The First Example of a Catalytic Asymmetric Aldol‐Tishchenko Reaction of Aldehydes and Aliphatic Ketones.
Authors: Mlynarski Jacek , Mitura Marcin
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Amberlyst 15‐Catalyzed Efficient Synthesis of 5‐Acetyl‐4‐hydroxy‐coumarone and 5‐Acetyl‐6‐hydroxy‐coumarone: Crucial Precursors for Several Naturally Occurring Furanoflavones.
Authors: Goel Atul , Dixit Manish
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Conversion of Indoline‐2‐thione and Oxindole to Isatin — Some New Observations.
Authors: Banerjee Satarupa , Sarkar Sandipan , Basak Ramkrishna , Chakrabarty Manas
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
The Development of New Bicyclic Pyrazole‐Based Cytokine Synthesis Inhibitors.
Authors: Townes Jennifer A. , et al. et al.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Novel 3‐Methyl‐4‐(O‐substituted‐oximino)‐pyrazolin‐5‐ones as Potent Inhibitors of Cdc25B Phosphatase.
Authors: Seo Min Jung , Kim Jung Ki , Son Bum Suk , Song Bo Gan , No Zaesung , Cheon Hyae Gyeong , Kim Kwang‐Rok , Sohn Young Sun , Kim Hyoung Rae
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Novel Chemical Modifications at the 4‐Position of Chromones. Synthesis and Reactivity of 4H‐Chromene‐4‐spiro‐5′‐isoxazolines and Related Compounds.
Authors: Sosnovskikh Vyacheslav Ya. , Usachev Boris I. , Sizov Aleksei Yu. , Kodess Mikhail I.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Synthesis of Dimeric Acridine Derived Antivirals.
Authors: Csuk Rene , Barthel Alexander , Brezesinski Torsten , Raschke Christian
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Synthesis and Thermal Transformations of 5‐Nitropyrimidin‐4‐yl Dialkyldithiocarbamates.
Authors: Ryabova O. B. , Makarov V. A. , Chernyshev V. V. , Granik V. G.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Synthesis and Molecular Structure of 2,4,8a‐Triaryl‐6‐methylperhydro[1,3,2]dioxaborinino[5,4‐c]pyridines.
Authors: Le Tuan Anh Le Tuan Anh , Polyanskii K. B. , Andresyuk A. N. , Soldatenkov A. T. , Mamyrbekova Zh. A. , Kuleshova L. N. , Khrustalev V. N.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Distannylation of Strained Carbon—Carbon Triple Bonds Catalyzed by a Palladium Complex.
Authors: Yoshida Hiroto , Tanino Kenji , Ohshita Joji , Kunai Atsutaka
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Preparation and Properties of Tetra‐ and Octa‐substituted Phthalocyanines with Cationic Trimethylaniliniumyl Groups.
Authors: Sugimori Tamotsu , Nojima Jun , Ozawa Tomohiro , Handa Makoto , Kasuga Kuninobu
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Astersedifolioside A—C, Three New Oleane‐Type Saponins with Antiproliferative Activity.
Authors: Corea Gabriella , Iorizzi Maria , Lanzotti Virginia , Cammareri Maria , Conicella Clara , Laezza Chiara , Bifulco Maurizio
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Efficient Solution Phase Parallel Synthesis of Norstatine Analogues.
Authors: Voronkov Michael V. , Gontcharov Alexander V. , Wang Zhi‐Min , Richardson Paul F. , Kolb Hartmuth C.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
A New Hydroxyjasmone Glucoside and Its Related Compounds from the Leaf of Thyme
Authors: Kitajima Junichi , Ishikawa Toru , Urabe Atushi
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Zyzzyanone A, a Novel Pyrrolo[3,2‐f]indole Alkaloid from the Australian Marine Sponge Zyzzya fuliginosa
Authors: Utkina Natalia K. , Makarchenko Aleksandra E. , Denisenko Vladimir A. , Dmitrenok Pavel S.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Synthesis of Benzimidazole Based Analogues of Sphingosine‐1‐phosphate: Discovery of Potent, Subtype‐Selective S1P4 Receptor Agonists.
Authors: Clemens Jeremy J. , Davis Michael D. , Lynch Kevin R. , Macdonald Timothy L.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
An Easy and Versatile Approach to the Synthesis of Chiral Pheromone Lactones via 4,4‐Dimethyl‐2‐oxazoline Derivatives.
Authors: Zarbin Paulo H. G. , Oliveira Alfredo R. M. , Dimonelli Fabio , Villar Jose A. F. P. , Delay Orlando Jr.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Synthesis of a Key Intermediate of Novel Galbonolide Analogues via Efficient Construction of a Conjugated Diene System.
Authors: Sakoh Hiroki , Jona Hideki , Sugimoto Yuichi , Imamura Hideaki , Sakuraba Shunji , Yamada Koji , Morishima Hajime
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Biomimetic Synthesis of a Leaf‐Opening Factor, Potassium Isolespedezate, by Direct Formation of Enol‐glycoside.
Authors: Sugimoto Takanori , Ueda Minoru
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Rare‐Earth Diiodides and Derivatives
Authors: Meyer Gerd , Gerlitzki Niels , Hammerich Stefanie
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Magnetic and Structural Properties of Amorphous and Nanocrystalline Materials
Authors: Schmool David S. , Garitaonandia Jose S.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Silylenes (and Germylenes, Stannylenes, Plumbylenes)
Authors: Tokitoh Norihiro , Ando Wataru
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Strained Hydrocarbons: Structures, Stability, and Reactivity
Authors: Wiberg Kenneth B.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Synthetic Carbene and Nitrene Chemistry
Authors: Doyle Michael P.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Nitrenes
Authors: Platz Matthew S.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Singlet Carbenes
Authors: Jones Maitland Jr. , Moss Robert A.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Non‐Kekule Molecules as Reactive Intermediates
Authors: Berson Jerome A.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Synthesis and Applications of (R)‐ and (S)‐Pantolactone as Chiral Auxiliaries
Authors: Camps Pelayo , Munoz‐Torrero Diego
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Metal—Salen Schiff Base Complexes in Catalysis: Practical Aspects
Authors: Cozzi Pier Giorgio
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Synthesis, Structures, and Reactions of Anions and Dianions of Group 14 Metalloles
Authors: Saito Masaichi , Yoshioka Michikazu
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Several Aspects of the Search for Anticonvulsants
Authors: Frolovskii V. A. , Studnev Yu. N. , Garibova T. L. , Voronina T. A.
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Outrunning the Bear
Authors: Reymond Jean‐Louis
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
UV—Visible Spectra and Photoacidity of Phenols, Naphthols and Pyrenols
Authors: Pines Ehud
Published: December 2004

For Abstract see ChemInform Abstract in Full Text.
Physikalisch‐chemische Probleme der Luftverunreinigung
Authors: Becker Karl H.
Published: December 2004

Die Bedeutung der Abgase aus Verbrennungsmotoren wie auch aus Düsenstrahltriebwerken spielt mit wachsender Motorisierung eine immer größere Rolle für die Luflverunreinigung. In den USA beträgt der Anteil auf diese Art entstandener Schadstoffe an der Gesamtbelastung heute schon mehr als 60%, in der Bundesrepublik liegt er über 40%.
Das Portrait: Joseph Achille Le Bel 1847–1930
Authors: Weyer Jost
Published: December 2004

Bild oben: Gruppenaufnahme vom Genfer Kongreß für chemische Nomenklatur 1892 (auf dem die berühmte „Genfer Nomenklatur”︁ verabschiedet wurde). In der ersten Reihe (sitzend) zweiter von links E. Patern` (vgl. Seite 132), daneben von links nach rechts C. Graebe, A.v.Baeyer, S. Cannizzaro und Ch. Friedel. Hinter v. Baeyer Emil Fischer, etwa auf gleicher Höhe mit ihm zwischen Cannizzaro und Friedel steht J.A. Le Bel. – Die unteren beiden Bilder zeigen Le Bel in jüngeren Jahren und hochbetagt; das rechte Photo stammt aus dem Buch „Vie et Oeuvres de Joseph‐Achille Le Bel”︁ von M. Delépine (Paris 1949). Das linke Bild wurde 1893 von Le Bel an G. Krause, Herausgeber der Chemiker‐Zeitung in Köthen, geschickt, welcher berühmte Chemiker seiner Zeit um ihre Biographie und ein Photo zu bitten pflegte, um sie bei Fälligkeit eines Nachrufes bei der Hand zu haben. Dieses Bild wurde offenbar von Le Bel selbst als besonders characteristisch empfunden, denn er hat es auch dem Herausgeber der „Biographies alsaciennes”︁, A. Meyer, zur Verfügung gestellt. Ein Exemplar muß sich auch im Besitz der Société Chimique de France befunden haben, denn sie wird in M. Delépines „La Synthèse Totale en Chimie Organique”︁ (Paris 1937) als Quelle für das dort ebenfalls veröffentlichte Photo genannt. [Photo oben und links unten: Deutsches Museum, München].
Das Experiment: Reaktionen mit Wursterschen Kationen
Authors: Nickel Ulrich
Published: December 2004

Unten: Stationäre Farbverteilung nach unvollständiger Oxidation von para‐Phenylendiaminen und Kupplung mit verschiedenen Kupplern (vgl. Tabelle 5).
Chemical Mace – Wie gefährlich ist Chloracetophenon??
Authors: Schrempf Alfred
Published: December 2004

Wofür arbeitet ihr? Ich halte dafür, daß das einzige Ziel der Wissenschaft darin besteht, die Mühseligkeit der menschlichen Existenz zu erleichtern. Wenn Wissenschaftler, eingeschüchtert durch selbstsüchtige Machthaber, sich damit begnügen, Wissen um des Wissens Willen aufzuhäufen, kann die Wissenschaft zum Krüppel gemacht werden, und eure Maschinen mögen nur neue Drangsal bedeuten. Ihr mögt mit der Zeit alles entdecken, was es zu entdecken gibt, und euer Fortschritt wird doch nur ein Fortschreiten von der Menschheit weg sein.

Bertolt Brecht, Leben des Galilei.
Chemie vor unserer Zeit: Antike Pigmente
Authors: Noll Walter
Published: December 2004

Wer nicht von dreitausend Jahren sich weiß Rechenschaft zu geben, bleib im Dunkeln unerfahren, mag von Tag zu Tage leben.
Chemie in Glühlampen
Authors: Binnewies Michael
Published: December 2004

Fassen wir das Gesagte noch einmal stich‐wortartig zusammen:

In Glühlampen nutzen wir aus, daß ein durch Stromfluß erhitzter Stoff elektromagnetische Strahlung mit einem Anteil im Bereich des sichtbaren Lichtes emittiert.
Wirkungsweise und Einsatz von Katalysatoren
Authors: Emig Gerhard
Published: December 2004

Ohne Einsatz von Katalysatoren sind die heutige chemische Industrie, aber auch viele Umweltschutztechniken nicht vorstellbar. Produkte, die aus chemischen Verbindungen hergestellt werden, welche erst durch katalytische Verfahren wirtschaftlich produziert werden konnten, sind aus unserem Leben nicht mehr wegzudenken und unentbehrlich geworden.

Der erste Teil dieses Beitrags geht auf die Grundlagen der Katalyse ein, wobei Aktivität und Selektivität von Katalysatoren sowie die Katalysatordesaktivierung im Vordergrund stehen. Im zweiten Teil wird dann anhand von wichtigen Anwendungsbeispielen im Bereich des Umweltschutzes die Bedeutung der Katalyse bei Emissionsverminderung, Prozeßvereinfachung, Rohstoffrückgewinnung sowie Rohstoff‐ und Energieeinsparung demonstriert.
Tsukuba, Kansai Science City und 24 mal „Technopolis”︁. Wissenschaftsstädte in Japan
Authors: Schmid Rolf D.
Published: December 2004

Japan ‐ ein Wirtschaftsriese mit regionalen Problemen

Die Wissenschaftsstadt Tsukuba bei Tokio, in weniger als 15 Jahren „auf der grünen Wiese”︁ errichtet, zählt heute ca. 150 000 Einwohner, zwei Universitäten und 47 Forschungseinrichtungen; in ihren Technologieparks haben sich fast 100 Firmen angesiedelt. Als Gegengewicht entsteht gegenwärtig im Ballungszentrum Osaka/Kyoto eine zweite Wissenschaftsstadt, die Kansai Science City. Ergänzend zu diesen nationalen Projekten werden an derzeit 24 Orten der japanischen Inselkette die Regionalverwaltungen dabei unterstützt, „Technopolis‐Städte”︁ zu errichten; damit sollen High‐Tech, Ausbildung und Wissenschaft gleichmäßig über die ganze Nation verbreitet werden.
Überwachung radioaktiver Stoffe in der Umwelt. Was kann ein Universitätsinstitut dazu beitragen?
Authors: Herrmann Günter
Published: December 2004

Zur Überwachung radioaktiver Stoffe in der Umwelt gibt es in der Bundesrepublik Deutschland schon seit Jahrzehnten mehrere, von staatlichen Institutionen getragene Meßnetze, die jeweils Teilbereiche abdecken. Seit Anfang der sechziger Jahre oberirdische Kernwaffentests weitgehend eingestellt worden sind, ging es im wesentlichen darum, den sich langsam verändernden Pegel langlebiger Stoffe zu verfolgen. Mit dem Reaktorunfall von Tschernobyl am 26. April 1986 um 01:30 h Ortszeit änderte sich diese Situation schlagartig: Ein komplexes Gemisch kurz‐ und langlebiger Radioisotope wurde in räumlich und zeitlich unterschiedlichem Umfang über die Bundesrepublik verstreut. Zahlreiche Arbeitsgruppen an Universitäts‐ und Forschungsinstituten haben daraufhin sofort ihre Arbeit unterbrochen und Instrumente und Mitarbeiter für die Analyse des Fallouts aus Tschernobyl verfügbar gemacht. Wie dies im einzelnen geschah, wie dabei Erfahrungen aus der wissenschaftlichen Arbeit der Institute nützlich wurden, wie sich aber auch Mängel zeigten, die zur Suche nach neuen Methoden führten – dies alles soll an der Arbeit einer Gruppe am Institut für Kernchemie der Universität Mainz exemplarisch demonstriert werden.
Der ökologische Zustand der Nordsee. Eine Diskussion aus der Sicht der biologischen Chemie
Authors: Höpner Thomas
Published: December 2004

Chrysochromulina polylepis hieß eine der neuen Lektionen, die wir im Jahr 1988 lernen mußten. Während Ökosystem‐Modellierer noch dabei waren, das Problem der Koexistenz vieler Algen im Phytoplankton des Meeres zu klären, wurde eine bisher wegen ihrer Kleinheit und untergeordneten Individuenzahl kaum bekannte Spezies plötzlich dominant und entfaltet bisher unbekannte biologische Wirkungen. Der Fall eignet sich zur Demonstration, wie komplex Probleme sind, die uns die Nordsee in immer dichterer Folge vorlegt.
Das Dilemma der Umweltpolitik. Oder Chemie und Politik in der Luft
Authors: Sodeau John R.
Published: December 2004

Chemiker und Politiker gleichen einander zumindest in einem Aspekt: Beide wissen, was ein Gleichgewichtssystem ist und welche Bedeutung es hat. Im Gegensatz zu ihm ist eine paradoxe Situation offensichtlich viel beunruhigender, da sie oft mit vorgefaßten Meinungen darüber, was vernünftig und möglich ist, in Konflikt gerät. Unsere Atmosphäre ist ein komplexes chemisches System, das sich im Zustand eines Quasi‐Gleichgewichts befindet und voller Paradoxa steckt. Debatten sind daher unvermeidlich.
Die Chemie des Honigs
Authors: Deifel Anton
Published: December 2004

Der Honig war eines der ersten Süßungsmittel des Menschen. Während alte Kulturen ihm magisch‐religiöse, ja göttliche Eigenschaften zugeschrieben haben, wird er eigentlich erst seit der Zeit der Griechen und Römer als Nahrungsmittel verwendet. Doch auch bei ihnen steht sein Gebrauch als Heilmittel und Gewürz noch im Vordergrund. Bis heute – bei einem Pro‐Kopf‐Verbrauch des Bundesbürgers von 1,3 kg (im Jahre 1986) – hat der Honig etwas von seinem besonderen Charakter behalten. Viele Menschen schreiben ihm besondere Heilwirkungen zu oder preisen ihn zumindest – im Gegensatz zum normalen Haushaltszucker – als besonders „gesund”︁. Die Fragen nach dem ernährungsphysiologischen Wert und den Heilwirkungen seien vorerst dahingestellt. Der vorliegende Artikel will unter anderem auch diesen Sachverhalten auf den Grund gehen. Vor allem aber möchte er die Inhaltsstoffe des Honigs vorstellen und sich mit den chemischen Vorgängen beschäftigen, die bei seiner Entstehung ablaufen.
Sanierung von Grundwasserschäden. Einsatz von Aktivkohle zur Beseitigung organischer Chlorverbindungen
Authors: Weinand Rudolf , von Kienle Hartmut
Published: December 2004

Berichte über Grundwasserschäden beunruhigen häufig die Öffentlichkeit und werfen die Frage auf, ob unser wichtigstes Lebensmittel, das Wasser, in Gefahr sei. Empfindlichere Spurenanalytik und neue Erkenntnisse über das Gefährdungspotential bestimmter Stoffe sind die wesentlichen Ursachen für die gestiegene Anzahl der entdeckten Schadensfälle. Dieser Umstand sollte zugleich Aufforderung wie Ansporn sein: Was kann die Chemie zur Behebung solcher Schäden beitragen?
Im hohlen Zahn des Löwen. Deutsche Chemiker in der Sowjetunion unmittelbar nach dem zweiten Weltkrieg
Authors: Neubauer Alfred
Published: December 2004

Zur Reparations‐ und Demontagepolitik der alliierten Siegermächte gegenüber Deutschland gehörte nach dem Zweiten Weltkrieg auch die Verbringung von Naturwissenschaftlern und Technikern vor allem aus rüstungsrelevanten Bereichen in die Siegerstaaten. Die Jagd auf diese Gehirne durch die westlichen Alliierten auf der einen und durch den östlichen Alliierten auf der anderen Seite trug schon das Kainsmerkmal des beginnenden Kalten Krieges zwischen diesen Mächten in sich. Es ist verständlich, daß die Sowjetunion, die die größten Opfer als überfallenes Land im Zweiten Weltkrieg auf sich nehmen mußte, ein besonders starkes Interesse auch an dieser Art von Reparationsleistungen entwickelte.
Rastertunnelmikroskopie an reinen und adsorbatbedeckten Oberflächen
Authors: Neddermeyer Henning
Published: December 2004

Gegenstand der vorliegenden Arbeit ist ein kleiner Überblick über Untersuchungen an reinen und adsorbatbedeckten Oberflächen in der Arbeitsgruppe des Autors. Sie sind dem eher konventionellen Bereich der Rastertunnelmikroskopie zuzuordnen, in dem an möglichst gut definierten, im Ultrahochvakuum (UHV) präparierten Proben gemessen wird. Es werden Ergebnisse an einer reinen Halbleiter‐ und Metalloberfläche [Si(100) bzw. Ni(100)] gezeigt sowie Ergebnisse nach Adsorption von Metallen (Ag) und Gasen (O2) im Submonolagenbereich auf diesen Substraten. Für die Erfassung von zeitlich veränderlichen Vorgängen auf Oberflächen wurde ein schnelles Rastertunnelmikroskop entwickelt, mit welchem z. B. die atomaren Effekte während der Adsorption verfolgt werden können. Diese Methode wurde erstmalig eingesetzt bei der Adsorption von O2 auf Si(111), wobei die verschiedenen Phasen der Sauerstoff‐Adsorption atomar aufgelöst sichtbar gemacht werden konnten.
Nachwachsende Rohstoffe. Nachholbedarf bei der Grundlagenforschung
Authors: Zoebelein Hans
Published: December 2004

Das Schlagwort „nachwachsende Rohstoffe”︁ entstand in der Erdölkriese der siebziger Jahre. Schon seit Jahrhunderten aber haben die handwerklichen Vorläufer der chemischen Industrie Stoffe pflanzlichen und tierischen Ursprungs als solche oder in Form ihrer Derivate für Produkte des täglichen Bedarfs eingesetzt. Ein Beispiel für solche Anwendungen ist das Sieden von Seife aus natürlichen Fetten. Erst seit Anfang unseres Jahrhunderts werden fossile Rohstoffe wie Kohle und Erdöl in großem Maßstab eingesetzt.
A Xenopus DNA microarray approach to identify novel direct BMP target genes involved in early embryonic development
Authors: Peiffer Daniel A. , Von Bubnoff Andreas , Shin Yongchol , Kitayama Atsushi , Mochii Makoto , Ueno Naoto , Cho Ken W.Y.
Published: December 2004

Bone morphogenetic proteins (BMPs), a subgroup of the transforming growth factor‐beta (TGF‐β) superfamily, were originally isolated from bone on the basis of their ability to induce ectopic bone development. Although BMPs are involved in a wide range of developmental and physiological functions, very few vertebrate target genes in this pathway have been identified. To identify target genes regulated by the BMP growth factor family in Xenopus, large‐scale microarray analyses were conducted to discover genes directly activated by this factor in dissociated animal cap tissues treated with a combination of the protein synthesis inhibitor cycloheximide and BMP2. Consequent expression patterns and behaviors of the most highly induced genes were analyzed by in situ and reverse transcriptase‐polymerase chain reaction analyses. Here, we describe two sets of the most highly induced direct BMP target genes identified using microarrays prepared from two different stages of early Xenopus development. A wide variety of genes are induced by BMP2, ranging from cell cycle controllers, enzymes, signal transduction cascade components, and components of the blood and vascular system. The finding reinforces the notion that BMP signals play important roles in a variety of biological processes. Developmental Dynamics 232:445–456, 2005. © 2004 Wiley‐Liss, Inc.
Global analysis of RAR‐responsive genes in the Xenopus neurula using cDNA microarrays
Authors: Arima Kayo , Shiotsugu Jason , Niu Rong , Khandpur Ritika , Martinez Mayra , Shin Yongchol , Koide Tetsuya , Cho Ken W.Y. , Kitayama Atsushi , Ueno Naoto , Chandraratna Roshantha A.S. , Blumberg Bruce
Published: December 2004

Retinoid signaling is important for patterning the vertebrate hindbrain and midaxial regions. We recently showed that signaling through retinoic acid receptors (RARs) is essential for anteroposterior patterning along the entire body axis. To further investigate the mechanisms through which RARs act, we used microarray analysis to investigate the effects of modulating RAR activity on target gene expression. We identified 334 up‐regulated genes (92% of which were validated), including known RA‐responsive genes, known genes that have never been proposed as RA targets and many hypothetical and unidentified genes (n = 166). Sixty‐seven validated down‐regulated genes were identified, including known RA‐responsive genes and anterior marker genes. The expression patterns of selected up‐regulated genes (n = 45) were examined at neurula stages using whole‐mount in situ hybridization. We found that most of these genes were expressed in the neural tube and many were expressed in anterior tissues such as neural crest, brain, eye anlagen, and cement gland. Some were expressed in tissues such as notochord, somites, pronephros, and blood islands, where retinoic acid (RA) plays established roles in organogenesis. Members of this set of newly identified RAR target genes are likely to play important roles in neural patterning and organogenesis under the control of RAR signaling pathways, and their further characterization will expand our understanding of RA signaling during development. Developmental Dynamics 232:414–431, 2005. © 2004 Wiley‐Liss, Inc.
Temporal and spatial manipulation of gene expression in Xenopus embryos by injection of heat shock promoter‐containing plasmids
Authors: Michiue Tatsuo , Asashima Makoto
Published: December 2004

The temporal and spatial manipulation of gene expression is useful in analyzing the mechanisms of early embryogenesis. This report describes a modified strategy to achieve controlled gene expression by directed plasmid injection using the hsp70 promoter and heat treatment. Two control genes, enhanced green fluorescent protein (EGFP) and β‐catenin, were also expressed by this method. When embryos were injected with HsS1/EGFP and subsequently heat‐treated, ectopic EGFP was expressed only in the injected area. No severe defects were attributable to the heat treatment alone. Western blotting confirmed that no EGFP induction occurred in the absence of heat treatment and that, in the presence of heat induction, EGFP expression was detected within 1 hr after treatment. These results suggest that heat‐mediated gene expression in the restricted area was regulated temporally. In addition, HsS1/β‐catenin injection into the animal pole of 8‐cell embryos, followed by heat treatment, caused loss of head formation that was similar to that seen with CS2/β‐catenin injection. Although a hormone‐inducible gene induction system already exists in Xenopus, our modified technique provides an alternative method for controlling temporal and spatial gene expression. Developmental Dynamics 232:369–376, 2005. © 2004 Wiley‐Liss, Inc.
Vascular gene expression and phenotypic correlation during differentiation of human embryonic stem cells
Authors: Gerecht‐Nir Sharon , Dazard Jean‐Eudes , Golan‐Mashiach Michal , Osenberg Sivan , Botvinnik Alex , Amariglio Ninette , Domany Eytan , Rechavi Gideon , Givol David , Itskovitz‐Eldor Joseph
Published: December 2004

The study of the cascade of events of induction and sequential gene activation that takes place during human embryonic development is hindered by the unavailability of postimplantation embryos at different stages of development. Spontaneous differentiation of human embryonic stem cells (hESCs) can occur by means of the formation of embryoid bodies (EBs), which resemble certain aspects of early embryos to some extent. Embryonic vascular formation, vasculogenesis, is a sequential process that involves complex regulatory cascades. In this study, changes of gene expression along the development of human EBs for 4 weeks were studied by large‐scale gene screening. Two main clusters were identified—one of down‐regulated genes such as POU5, NANOG, TDGF1/Cripto (TDGF, teratocarcinoma‐derived growth factor‐1), LIN28, CD24, TERF1 (telomeric repeat binding factor‐1), LEFTB (left–right determination, factor B), and a second of up‐regulated genes such as TWIST, WNT5A, WT1, AFP, ALB, NCAM1. Focusing on the vascular system development, genes known to be involved in vasculogenesis and angiogenesis were explored. Up‐regulated genes include vasculogenic growth factors such as VEGFA, VEGFC, FIGF (VEGFD), ANG1, ANG2, TGFβ3, and PDGFB, as well as the related receptors FLT1, FLT4, PDGFRB, TGFβR2, and TGFβR3, other markers such as CD34, VCAM1, PECAM1, VE‐CAD, and transcription factors TAL1, GATA2, and GATA3. The reproducibility of the array data was verified independently and illustrated that many genes known to be involved in vascular development are activated during the differentiation of hESCs in culture. Hence, the analysis of the vascular system can be extended to other differentiation pathways, allocating human EBs as an in vitro model to study early human development. Developmental Dynamics 232:487–497, 2005. © 2004 Wiley‐Liss, Inc.
Enhanced‐discretization successive update method (EDSUM)
Authors: Tezduyar Tayfun E. , Sathe Sunil
Published: December 2004

The enhanced‐discretization successive update method (EDSUM) is a multi‐level iteration method designed for computation of the flow behaviour at small scales. As an enhancement in iterative solution of non‐linear and linear equation systems, the EDSUM is one of the enhanced discretization and solution techniques developed for more effective computation of complex flow problems. It complements techniques based on enhancement in spatial discretization and based on enhancement in time discretization in the context of a space–time formulation. It is closely related to the enhanced‐discretization interface‐capturing technique (EDICT), as the function spaces used in the EDSUM are very similar to those used in the EDICT. The EDSUM also has a built‐in mechanism for transferring flow information between the large and small scales in a fashion consistent with the discretizations resulting from the underlying stabilized formulations. With a number of test computations for steady‐state problems governed by the advection–diffusion equation, we demonstrate that the EDSUM has the potential to become a competitive technique for computation of flow behaviour at small scales. Copyright © 2004 John Wiley & Sons, Ltd.
Quantifying uncertainty of the semivariogram of transmissivity of an existing groundwater monitoring network
Authors: Lin Gwo‐Fong , Chen Guo‐Rong
Published: December 2004

A method is presented for quantifying the uncertainty of the semivariogram of transmissivity and determining the required number of measurements. In this method, the estimated semivariogram and its 95% confidence limits are first determined from a finite number of measurements. The uncertainty of the estimated semivariogram is then quantified using the random field simulation technique. For a given value of the quantitative index of uncertainty, the required number of measured data can finally be obtained. Actual transmissivity data of an existing groundwater monitoring network are used in the application of the proposed method. The required numbers of measurements of transmissivity for four different values of the quantitative index of uncertainty are provided, from which reliable semivariograms of the transmissivity can be obtained. Copyright © 2004 John Wiley & Sons, Ltd.