bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phosphorus Addition atsp2Carbon
Authors: Engel Robert 
Published: February 2005

AbstractIn recent years a renewed interest in the synthesis of organophosphorus compounds has appeared. This has been the result principally of the development of new applications of materials bearing a carbon–phosphorus linkage for chemical synthesis, biological regulation, and a variety of industrial uses.In chemical syntheses the phosphoryl function has been found to be of great utility as an activator for two major categories of transformations. The first of these is the generation of new carboncarbon double bonds through the phosphoryl‐stabilized anion modifications of the Wittig reaction. For these reactions, the phosphoryl function increases the acidity of the hydrogen of the carbon attached to phosphorus and, after addition to a carbonyl linkage, is usually eliminated as a water‐soluble byproduct. Alternatively, the initially formed phosphonate anion may be used as a nucleophile in a substitution reaction leading to a derived phosphonate product having its own synthetic utility.In the second category of transformations an appropriately functionalized phosphonate reacts at the carbon attached to phosphorus to give products that can be envisioned as resulting from reaction of an electrophilic substrate with a carbonyl group of inverted polarity. The phosphoryl function, which is generally eliminated in the formation of the target material, facilitates these “umpolung” reactions that could not be accomplished directly with a parent material bearing the simple carbonoxygen double bond.With regard to biological applications, the synthesis of organophosphorus compounds has been of interest for several reasons. Among these is the discovery in a variety of organisms of naturally occurring compounds bearing the carbonphosphorus bond. Phosphonomycin and aminoethylphosphonic acid are two well‐known examples of such compounds. It has also been recognized that phosphonates may be capable of perturbing metabolic processes normally involving phosphates of similar structure. In addition, materials with other metabolic regulatory capabilities have been found. As a result, there have been not only syntheses of many new organophosphorus compounds but also the development of improved methods for such syntheses.The review presented in this chapter is concerned with one approach to carbonphosphorus bond formation that is particularly significant for the aforementioned applications, specifically the addition of a (formally) trivalent phosphorus ester or amide to an unsaturated carbon linkage under polar reaction conditions. Reactions of a variety of types of phosphorus reagents with simple carbonyl compounds, imines, and other related polar unsaturated carbon functions, as well as conjugate addition reactions, are reviewed.
The Electrophilic Substitution of Allylsilanes and Vinylsilanes
Authors: Fleming Ian , Dunoguès Jacques , Smithers Roger 
Published: February 2005

AbstractAllylsilanes and vinylsilanes usually react with electrophiles to give substitution. These reactions are conveniently understood as the reactions of alkenes that have been significantly but only slightly modified by the presence of the silyl group. In both reactions, substitution is favored over addition, and both the site of attack and the site of the double bond in the product are usually determined by the site of the silyl group in the starting material.In this chapter only the electrophilic substitution reactions of allylsilanes, vinylsilanes, and allenylsilanes is discussed. It is further restricted to the reactions of tetraorganosilanes because they are synthetically the most interesting in the laboratory. However, although they are not included in the tables, allylsilanes and vinylsilanes that react by addition rather than substitution or that are not tetraorganosilanes are referred to occasionally in the text wherever their reactions illuminate the discussion. Many of the features of the reactions discussed here are shared by the reactions of arylsilanes, ethynylsilanes, propargylsilanes, cyclopropylsilanes, and cyclopropylmethylsilanes. The methods by which allylsilanes and vinylsilanes are synthesized have been summarized in several places.Stereochemsitry of reactions of allenylsilanes and vinylsilanes is discussed. Scope and limitations include discussions of protodesilylation and deuterodesilyation and the use of carbon, nitrogen, and oxygen as electrophiles. Other electrophiles include phosphorus, sulfur, metals, halogens, and selenium. All of these are covered in the extensive tabular material
Orthogonale multipolare Wechselwirkungen in chemischen und biologischen Strukturen
Authors: Paulini Ralph , Müller Klaus , Diederich François 
Published: February 2005

AbstractEine Vielzahl von Studien zur molekularen Erkennung hat unser Wissen über apolare und durch H‐Brücken vermittelte Wechselwirkungen sowie Wechselwirkungen zwischen Ionen und Dipolen in den letzten Jahrzehnten beträchtlich erweitert. Weit weniger Beachtung wurde hingegen der Rolle multipolarer Wechselwirkungen (insbesondere solcher mit orthogonaler Anordnung) beim Aufbau eines Kristallgitters oder bei der Stabilisierung von Komplexen biologischer Rezeptoren geschenkt. Das Ziel dieses Aufsatzes ist es daher, anhand von Ergebnissen aus Datenbankrecherchen eine Übersicht über die unterschiedlichen Typen dieser bislang oft übersehenen Wechselwirkungen und ihre strukturellen Charakteristiken zu geben. Die vielen Beispiele solcher Wechselwirkungen, die in Kristallstrukturen kleiner Moleküle und Protein‐Ligand‐Komplexen identifiziert wurden, sind ein Beleg für ihre Bedeutung bei molekularen Erkennungsprozessen in der Chemie und der Biologie.
CoII5(OH)6(SO4)2 (H2O)4: The First Ferromagnet Based on a Layered Cobalt—Hydroxide Pillared by Inorganic ×××OSO3—Co (H2O)4—O3SO×××.
Authors: Ben Salah Mohsen , Vilminot Serge , Richard‐Plouet Mireille , Andre Gilles , Mhiri Tahar , Kurmoo Mohamedally 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
3D‐Coordination Cluster Polymers [Ln(H2O)3Re6Te8(CN)6] ×nH2O (Ln: La3+, Nd3+): Direct Structural Analogy with the Mononuclear LnM(CN)6×nH2O Family.
Authors: Artemkina Sofia B. , Naumov Nikolai G. , Virovets Alexander V. , Fedorov Vladimir E. 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis, Structure, and Derivatives of endo‐4‐Aminomethyltetracyclo [6.2.1.13,6.02,7]dodec‐9‐ene.
Authors: Kas'yan L. I. , Golodaeva E. A. , Okovityi S. I. , Kas'yan A. O. , Karpenko D. V. , Umrykhina L. K. 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Mesogenic 4‐(ω‐Hydroxyalkoxy)‐4′‐formylazobenzenes.
Authors: Kuvshinova S. A. , Zav'yalov A. V. , Koifman O. I. , Aleksandriiskii V. V. , Burmistrov V. A. 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of Substituted Naphthalenes from α‐Tetralones Generated by a Xanthate Radical Addition—Cyclization Sequence.
Authors: Cordero‐Vargas Alejandro , Perez‐Martin Ines , Quiclet‐Sire Beatrice , Zard Samir Z. 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Syntheses of Morpholine‐2,3‐diones and 2‐Hydroxymorpholin‐3‐ones: Intermediates in the Synthesis of Aprepitant.
Authors: Nelson Todd D. , Rosen Jonathan D. , Brands Karel M. J. , Craig Bridgette , Huffman Mark A. , McNamara James M. 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Identification of the Polar Constituents of Potamogeton Species by HPLC‐UV with Post‐Column Derivatization, HPLC‐MSn and HPLC‐NMR, and Isolation of a New ent‐Labdane Diglycoside.
Authors: Waridel Patrice , Wolfender Jean‐Luc , Lachavanne Jean‐Bernard , Hostettmann Kurt 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Oxygenated Diterpenes and Other Constituents from Moroccan Juniperus phoenicea and Juniperus thurifera Var. africana
Authors: Barrero Alejandro F. , Quilez del Moral Jose F. , Herrador M. Mar , Akssira Mohamed , Bennamara Ahmed , Akkad Said , Aitigri Mohamed 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
meso‐Aryl‐β‐pyrrolic Positions Interactions in meso‐Tetraarylporphyrins: Flat Arylporphyrins and Building Blocks for Oligoporphyrins
Authors: Callot Henry J. , Ruppert Romain , Jeandon Christophe , Richeter Sebastien 
Published: February 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Long‐term survival probabilities for childhood rhabdomyosarcoma
Authors: Punyko Judith A. , Mertens Ann C. , Baker K. Scott , Ness Kirsten K. , Robison Leslie L. , Gurney James G. 
Published: February 2005

AbstractBACKGROUNDEvidence from clinical trials has documented improvements in event‐free survival from childhood rhabdomyosarcoma (RMS) since the 1970s; however, the survival experience of children enrolled on cancer clinical trials may not reflect the full range of patients treated in community settings. The current study evaluated 5‐year survival and 10‐year conditional survival for RMS from U.S. population‐based cancer registry data.METHODSPublic‐use data from the Surveillance, Epidemiology, and End Results (SEER) program were used in life table and Cox regression analyses to evaluate RMS survival by patient age at diagnosis, gender, tumor histology, tumor site and stage, and major treatment eras among 848 children who were age < 20 years at the time of diagnosis, were a resident of 1 of 9 geographic reporting regions, and were diagnosed between 1973 and 2000.RESULTSThe 5‐year survival probabilities were found to be highest for younger‐age children (ages 1–4 years: 77%), patients with localized disease (83%), those whose tumors had an embryonal histology (67%), and patients with orbital (86%) and genitourinary (80%) tumor sites. Poor prognosis was associated with diagnosis during infancy (47%) and adolescence (48%); metastatic disease at the time of presentation (31%); alveolar histology (49%); and tumors of the extremities (50%), retroperitoneum (52%), and trunk (52%). Conditional 10‐year survival probabilities among those who survived ≥ 5 years were 85% or higher. The probability of survival by stage at the time of diagnosis increased with each successive treatment era, suggesting a stage shift phenomenon over time.CONCLUSIONSLarge variations in 5‐year survival were evident depending on patient age and tumor characteristics. However, children who survived the first 5 years after diagnosis were found to have an excellent long‐term prognosis. The patterns in RMS survival noted from the current population‐based evaluation did not appear to differ substantially from those previously reported by major clinical trials. Cancer 2005. © 2005 American Cancer Society.
Characterization and modelling of the spatial heterogeneity of snowmelt erosion
Authors: Ollesch G. , Sukhanovski Y. , Kistner I. , Rode M. , Meissner R. 
Published: February 2005

AbstractRecent studies about soil erosion show that erosion rates in winter can reach or exceed erosion induced by summer events. A factor of particular importance is the incidence of frozen soil, which modifies the surface runoff generation and also the erodibility of the soil. In this paper, investigations are conducted to characterize the snowmelt erosion events in the 1·44 km2 ‘Schäfertal’ research catchment that is located c. 150 km southwest of Berlin. Two runoff events of different initial conditions are compared and analysed. Although the net erosion rate in the catchment is relatively low, the described event with soil frost is considerably different from the event without soil frost. For example, the net erosion, maximum and median suspended sediment concentrations are significantly higher for the event with frozen soil. The results presented suggest that the sediment source areas differ for both situations. On one hand the channel or sediment flushing is identified as the source, while on the other hand hill slope processes and intra‐storm variations are recognized for the soil frost situation. A model modification is presented to improve the estimation of spatial differentiation of surface runoff within the continuous hydrological model WaSim, which is linked to the erosion model AGNPS. Based on measurements of topsoil temperature at locations with diverse exposition and land use, an algorithm is developed. The average agreement of air temperature to the calculated topsoil temperature is r2 = 0·75. The spatial information about soil frost is utilized to modify the infiltration characteristics of the soil. Hence, the spatial aspects of runoff generation in winter conditions and the related transport of sediment is considered in a more realistic way. The spatial results of the modelling are plausible but the estimation of erosion needs further improvement. Copyright © 2005 John Wiley & Sons, Ltd.
Barchan dunes: why they cannot be treated as ‘solitons’ or ‘solitary waves’
Authors: Livingstone Ian , Wiggs Giles F. S. , Baddock Matthew 
Published: February 2005

AbstractSchwämmle and Herrmann (Nature, 2003, vol. 426, p. 619) have suggested that two sub‐aerial barchan sand dunes could ‘pass through one another while still preserving their shape’ in a manner similar to solitons or solitary waves. A wide range of published field and wind tunnel evidence suggests that this assertion should not go unchallenged. Copyright © 2005 John Wiley & Sons, Ltd.
Long‐term tracing of adenoviral expression in rat and rabbit using luciferase imaging
Authors: Li Jin Zhong , Holman David , Li Hongwei , Liu An‐Hsiang , Beres Brian , Hankins Gerald R , Helm Gregory A 
Published: February 2005

AbstractBackgroundLuciferase optical imaging provides a novel method to monitor transgene expression in small living animals. As the genetic and immunological heritages of particular animals significantly affect the expression of adenovirus‐delivered transgenes, it is essential to know the expression patterns specific to athymic nude and Sprague‐Dawley rats, two strains commonly used in rodent models. In this study we set out to determine these patterns. At the same time, we tested luciferase optical imaging in a larger animal, the rabbit.MethodsA recombinant luciferase adenoviral vector was injected subcutaneously or intramuscularly into athymic nude rats, Sprague‐Dawley rats, and Dutch Belted rabbits. The luciferase expression was assessed using a cooled charge‐coupled device.ResultsThe luminescent signal was capable of passing through at least 1.3 cm of muscle tissue and proved to be much stronger when luciferin was delivered via a local injection than by an intraperitoneal injection. Although the types of immune cells differed between immunodeficient and immunocompetent rats, similar amounts and patterns of luciferase expression were observed in the musculature in two rat strains during the 1st month after a viral intramuscular injection. The duration of luciferase expression was longer than 15 months in athymic nude rats, 9 months in Sprague‐Dawley rats, and 6 months in rabbits following a direct viral injection.ConclusionsLuciferase expression after adenoviral gene delivery can persist for longer than 6 months, even in immunocompetent animals. Live imaging of luciferase expression can be performed not only in small animals, but also in larger animals such as rabbits. Copyright © 2005 John Wiley & Sons, Ltd.
p‐quinone mediates 6‐hydroxydopamine‐induced dopaminergic neuronal death and ferrous iron accelerates the conversion of p‐quinone into melanin extracellularly
Authors: Izumi Yasuhiko , Sawada Hideyuki , Sakka Noriko , Yamamoto Noriyuki , Kume Toshiaki , Katsuki Hiroshi , Shimohama Shun , Akaike Akinori 
Published: February 2005

AbstractParkinson's disease (PD) is characterized by the selective loss of dopaminergic neurons in the substantia nigra (SN). 6‐Hydroxydopamine (6‐OHDA), a dopaminergic neurotoxin, is detected in human brains and the urine of PD patients. Using SH‐SY5Y, a human neuroblastoma cell line, we demonstrated that 6‐OHDA toxicity was determined by the amount of p‐quinone produced in 6‐OHDA auto‐oxidation rather than by reactive oxygen species (ROS). Glutathione (GSH), which conjugated with p‐quinone, provided significant protection whereas catalase, which detoxified hydrogen peroxide and superoxide anions, failed to block cell death caused by 6‐OHDA. Although iron accumulated in the SN of patients with PD can cause dopaminergic neuronal degeneration by enhancing oxidative stress, we found that extracellular ferrous iron promoted the formation of melanin and reduced the amount of p‐quinone. The addition of ferrous iron to the culture medium inhibited caspase‐3 activation and apoptotic nuclear morphologic changes and blocked 6‐OHDA‐induced cytotoxicity in SH‐SY5Y cells and primary cultured mesencephalic dopaminergic neurons. These data suggested that generation of p‐quinone played a pivotal role in 6‐OHDA‐induced toxicity and extracellular iron in contrast to intracellular iron was protective rather than harmful because it accelerated the conversion of p‐quinone into melanin. © 2005 Wiley‐Liss, Inc.
Successful antifungal combination therapy with voriconazole and caspofungin
Authors: Schuster Friedhelm , Moelter Christian , Schmid Irene , Graubner Ulrike B. , Kammer Birgit , Belohradsky Bernd H. , Führer Monika 
Published: February 2005

AbstractA 12‐year‐old boy in third remission of an acute lymphoblastic leukaemia developed infection of lung and paranasal sinuses with Aspergillus flavus in neutropenia. Because of the high risk of leukaemia‐relapse bone marrow transplantation (BMT) from a matched unrelated donor was carried out despite invasive pulmonary aspergillosis (IPA). It is the first reported patient with IPA, who was successfully treated by the antifungal combination therapy with voriconazole and caspofungin therapy during myeloablative BMT. Despite 6 weeks of aplasia, a dramatic decrease of lesions highly suggestive of aspergillosis was observed after BMT. Since discharge‐oral voriconazole monotherapy has been continued. Pediatr Blood Cancer 2005;44:682–685. © 2005 Wiley‐Liss, Inc.
Crystallization behavior of P(EN‐co‐ET) copolyesters: Crystallization kinetics and morphology revealed by DSC, time‐resolved SAXS analysis, and TEM
Authors: Lee Wan Duk , Im Seung Soon 
Published: February 2005

AbstractThe crystallization kinetics and morphology of PEN/PET copolyesters were investigated using differential scanning calorimetry (DSC), time‐resolved small‐angle X‐ray scattering (TR‐SAXS), and transmission electron microscopy (TEM). The Avrami exponents obtained using DSC were approximately 3 for homo PEN and 4 for all the copolyesters. The 3‐parameter Avrami model was successfully fitted to the invariants with respect to the time obtained from TR‐SAXS, and the exponent values were similar to those obtained from DSC. Moreover, the Avrami rate constants obtained from TR‐SAXS showed marked temperature‐sensitive decreases in all samples, like those obtained from DSC. This indicates that not only could changes in morphological parameters be obtained from the analysis of TR‐SAXS data but also crystallization kinetics. The changes in the morphological parameters determined from the SAXS data indicate that the minor components, dimethyl terephthalate (DMT) segments, are rejected into the amorphous phase during crystallization. In the TEM study, copolyesters crystallized at temperature above 240 °C grew into both the α‐ and β‐form, although 240 °C is the optimum condition for the β‐form crystal. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 805–816, 2005
Quantitative analysis of the microscale of auxetic foams
Authors: Gaspar N. , Smith C. W. , Miller E. A. , Seidler G. T. , Evans K. E. 
Published: February 2005

AbstractThe auxetic foams first produced by Lakes have been modelled in a variety of ways, each model trying to reproduce some observed feature of the microscale of the foams. Such features include bent or broken ribs or inverted angles between ribs. These models can reproduce the Poisson's ratio or Poisson's function of auxetic foam if the model parameters are carefully chosen. However these model parameters may not actually reflect the internal structure of the foams. A big problem is that measurement of parameters such as lengths and angles is not straightforward within a 3‐d sample. In this work a sample of auxetic foam has been imaged by 3‐d X‐ray computed tomography. The resulting image is translated to a form that emphasises the geometrical structure of connected ribs. This connected rib data are suitably analysed to describe both the microstructural construction of auxetic foams and the statistical spread of structure, that is, the heterogeneity of an auxetic foam. From the analysis of the microstructure, observations are made about the requirements for microstructural models and comparisons made to previous existing models. From the statistical data, measures of heterogeneity are made that will help with future modelling that includes the heterogeneous aspect of auxetic foams. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Auxetic behaviour from rotating rigid units
Authors: Grima J. N. , Alderson A. , Evans K. E. 
Published: February 2005

AbstractAuxetic materials exhibit the unexpected feature of becoming fatter when stretched and narrower when compressed, in other words, they exhibit a negative Poisson's ratio. This counter‐intuitive behaviour imparts many beneficial effects on the material's macroscopic properties that make auxetics superior to conventional materials in many commercial applications. Recent research suggests that auxetic be‐haviour generally results from a cooperative effect between the material's internal structure (geometry setup) and the deformation mechanism it undergoes when submitted to a stress. Auxetic behaviour is also known to be scale‐independent, and thus, the same geometry/deformation mechanism may operate at the macro‐, micro‐ and nano‐ (molecular) level. A considerable amount of research has been focused on the ‘re‐entrant honeycomb structure’ which exhibits auxetic behaviour if deformed through hinging at the joints or flexure of the ribs, and it was proposed that this ‘re‐entrant’ geometry plays an impor‐ tant role in generating auxetic behaviour in various forms of materials ranging from nanostructured polymers to foams. This paper discusses an alternative mode of deformation involving ‘rotating rigid units’ which also results in negative Poisson's ratios. In its most ideal form, this mechanism may be construc‐ ted in two dimensions using ‘rigid polygons’ connected together through hinges at their vertices. On application of uniaxial loads, these ‘rigid polygons’ rotate with respect to each other to form a more open structure hence giving rise to a negative Poisson's ratio. This paper also discusses the role that ‘rotating rigid units’ are thought to have in various classes of materials to give rise to negative Poisson's ratios. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Searching for auxetics with DYNA3D and ParaDyn
Authors: Hoover Wm. G. , Hoover C. G. 
Published: February 2005

AbstractWe sought to simulate auxetic behavior by carrying out dynamic analyses of mesoscopic model structures. We began by generating nearly periodic cellular structures. Four‐node “Shell” elements and eight‐node “Brick” elements are the basic building blocks for each cell. The shells and bricks obey standard elastic‐plastic continuum mechanics. The dynamical response of the structures was next determined for a three‐stage loading process: (1) homogeneous compression; (2) viscous relaxation; (3) uniaxial compression. The simulations were carried out with both serial and parallel computer codes – DYNA3D and ParaDyn – which describe the deformation of the shells and bricks with a robust contact algorithm. We summarize the results found here. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)