bluuebunny/crossref_metadata_2025_split huggingface dataset:
Amplicon DNA Melting Analysis for Mutation Scanning and Genotyping: Cross-Platform Comparison of Instruments and Dyes
Authors: Herrmann Mark G , Durtschi Jacob D , Bromley L Kathryn , Wittwer Carl T , Voelkerding Karl V 
Published: January 2006

Abstract
Background: DNA melting analysis for genotyping and mutation scanning of PCR products by use of high-resolution instruments with special “saturation” dyes has recently been reported. The comparative performance of other instruments and dyes has not been evaluated.
Methods: A 110-bp fragment of the β-globin gene including the sickle cell anemia locus (A17T) was amplified by PCR in the presence of either the saturating DNA dye, LCGreen Plus, or SYBR Green I. Amplicons of 3 different genotypes (wild-type, heterozygous, and homozygous mutants) were melted on 9 different instruments (ABI 7000 and 7900HT, Bio-Rad iCycler, Cepheid SmartCycler, Corbett Rotor-Gene 3000, Idaho Technology HR-1 and LightScanner, and the Roche LightCycler 1.2 and LightCycler 2.0) at a rate of 0.1 °C/s or as recommended by the manufacturer. The ability of each instrument/dye combination to genotype by melting temperature (Tm) and to scan for heterozygotes by curve shape was evaluated.
Results: Resolution varied greatly among instruments with a 15-fold difference in Tm SD (0.018 to 0.274 °C) and a 19-fold (LCGreen Plus) or 33-fold (SYBR Green I) difference in the signal-to-noise ratio. These factors limit the ability of most instruments to accurately genotype single-nucleotide polymorphisms by amplicon melting. Plate instruments (96-well) showed the greatest variance with spatial differences across the plates. Either SYBR Green I or LCGreen Plus could be used for genotyping by Tm, but only LCGreen Plus was useful for heterozygote scanning. However, LCGreen Plus could not be used on instruments with an argon laser because of spectral mismatch. All instruments compatible with LCGreen Plus were able to detect heterozygotes by altered melting curve shape. However, instruments specifically designed for high-resolution melting displayed the least variation, suggesting better scanning sensitivity and specificity.
Conclusion: Different instruments and dyes vary widely in their ability to genotype homozygous variants and scan for heterozygotes by whole-amplicon melting analysis.
The crystal structure of Cu1.78Bi4.73Se8, an N = 3 pavonite homologue with a Cu-for-Bi substitution
Authors: Makovicky Emil , Søtofte Inger , Karup-Møller Sven 
Published: January 2006

Summary
Cu1.78Bi4.73Se8, synthesized in a dry phase system Cu—Bi—Se at 450 °C, is monoclinic, a = 13.759 Å, b = 4.168 Å, c = 14.683 Å, γ = 115.61°, space group C2/m. It is an N = 3 member of the pavonite homologous series, with the composition limits Cu1.96Bi4.67Se8—Cu1.77Bi4.60S8—Cu1.25Bi4.91Se8. The crystal structure is composed of two types of alternating slabs, with configurations typical for the above series. The first kind of slabs contains paired square pyramidal columns of Bi3, interconnected by octahedral columns with three distinct statistical copper sites (flattened tetrahedral sites in the octahedral interior and a tetrahedral site between adjacent octahedra). They add up to nearly 1.5 Cu. The second kind of slabs contains central octahedra of Bi1, flanked by marginal distorted octahedra of Bi2. These Bi sites are partly replaced by statistically occupied Cu1-3 sites, in flat-tetrahedral and irregular trigonal-planar coordinations. Details of the Cu-for-Bi substitutions are discussed and comparisons with other N = 3 homologues of pavonite are made in the paper.
Crystal structures of the [18]-crown-6 ammoniate C12H24O6 · 2 NH3 and the cryptand [2.2.2] ammoniate C18H36O6N2 · 2 NH3
Authors: Suchentrunk Christof , Roßmeier Thomas , Korber Nikolaus 
Published: January 2006

Summary
The crystal structures of the new polyether ligand-ammoniates C12H24O6 · 2 NH3 (1) and C18H36O6N2 · 2 NH3 (2) have been elucidated at 123 K by single crystal X-ray structure analysis. Compound 1 crystallizes as yellow plate-like crystals in the monoclinic space group P21/c (no. 14) with unit cell parameters a = 7.572(4) Å, b = 7.724(4) and c = 14.448(7) Å with an angle β = 91.79(6)°. It consists of a molecule of [18]-crown-6 to which two ammonia molecules of crystallisation are bound by three hydrogen bonds each. The ammonia molecules reside below and above the plane of the crown ether oxygen atoms. Compound 2 crystallizes as colourless isometric crystals in the space group P6322 (no. 182) with unit cell parameters a = 8.2568(5) Å and c = 18.992(2) Å. It consists of molecules of cryptand [2.2.2] which are connected by hydrogen bonds via ammonia molecules of crystallisation, resulting in two-dimensional layers parallel to the ab-plane.
Magnetic Properties of Quinoidal Oligothiophenes: More Than Good Candidates for Ambipolar Organic Semiconductors?
Authors: Ponce Ortiz R. , Casado J. , Hernández V. , López Navarrete J. T. , Ortí E. , Viruela P. M. , Milián B. , Hotta S. , Zotti G. , Zecchin S. , Vercelli B. 
Published: January 2006

AbstractA series of quinoidal oligothiophenes have been investigated by means of solid‐state Fourier‐transform (FT)‐Raman and electron spin resonance (ESR) spectroscopies complemented with density functional theory calculations. FT‐Raman spectra recorded as a function of temperature show that, upon laser irradiation, the molecules undergo a reversible structural evolution from a quinoid‐type pattern at low temperature to an aromatic‐type pattern at high temperature. Moreover, ESR spectra show that a portion of these compounds exists in a biradical state at room temperature. These seemingly disconnected findings and others, such as conformational isomerism, are consistently explained by the consideration of biradical species associated with the presence of low‐lying triplet electronic states. In addition to the well‐established versatility of quinoidal oligothiophenes regarding ambipolar electrical actuation in field‐effect transistors, the exhibition of dual electrical and magnetic behavior leads to the prospect of new materials that have tunable electrical, optical, and magnetic properties.
Hydrogen Adsorption in Metal–Organic Frameworks: Cu‐MOFs and Zn‐MOFs Compared
Authors: Panella B. , Hirscher M. , Pütter H. , Müller U. 
Published: January 2006

AbstractHydrogen adsorption in two different metal–organic frameworks (MOFs), MOF‐5 and Cu‐BTC (BTC: benzene‐1,3,5‐tricarboxylate), with Zn2+ and Cu2+ as central metal ions, respectively, is investigated at temperatures ranging from 77 K to room temperature. The process responsible for hydrogen storage in these MOFs is pure physical adsorption with a heat of adsorption of approximately –4 kJ mol–1. With a saturation value of 5.1 wt.‐% for the hydrogen uptake at high pressures and 77 K, MOF‐5 shows the highest storage capacity ever reported for crystalline microporous materials. However, at low pressures Cu‐BTC shows a higher hydrogen uptake than MOF‐5, making Cu‐based MOFs more promising candidates for potential storage materials. Furthermore, the hydrogen uptake is correlated with the specific surface area for crystalline microporous materials, as shown for MOFs and zeolites.
Y‐Zeolite‐Catalyzed Cyclizations of Terpenols
Authors: Yu Wei , Bian Fengling , Gao Yuan , Yang Li , Liu Zhong‐Li 
Published: January 2006

AbstractDepending on the metal doped and the activation temperature, Y‐zeolites can catalyze a diversity of reactions of geraniol (1), linalool (2) and nerol (3). Compound 1 can be transformed to α‐ and/or γ‐cyclogeraniol (4 and 5) highly efficiently.
Solid Acid Catalysts for Biodiesel Production –‐Towards Sustainable Energy
Authors: Kiss Anton A. , Dimian Alexandre C. , Rothenberg Gadi 
Published: January 2006

AbstractThe advantages of biodiesel as an alternative fuel and the problems involved in its manufacturing are outlined. The pros and cons of making biodiesel via fatty acid esterification using solid acid catalysts are examined. The main problem is finding a suitable catalyst that is active, selective, and stable under the process conditions. Various solid acids (zeolites, ion‐exchange resins, and mixed metal oxides) are screened as catalysts in the esterification of dodecanoic acid with 2‐ethylhexanol, 1‐propanol, and methanol at 130–180 °C. The most promising candidate is found to be sulphated zirconia. The catalyst's stability towards thermal decomposition and leaching is tested and the effects of the surface composition and structure on the catalytic activity are discussed.
Metal‐Doped Epoxy Resins –‐New Catalysts for the Epoxidation of Alkenes with High Long‐Term Activities
Authors: Arnold Ulrich , Habicht Wilhelm , Döring Manfred 
Published: January 2006

AbstractFor the first time, the use of epoxy resins for the immobilisation of catalytically active metal species is reported. The resins were cured using metal acetylacetonates and alkoxides as polymerisation initiators and the thus obtained thermosets were tested as epoxidation catalysts. Outstanding long‐term catalyst activities and selectivities were observed for molybdenum‐containing resins in the epoxidation of cyclohexene with tert‐butyl hydroperoxide. Mechanistic investigations indicate a superposition of heterogeneous and homogeneous catalysis and a heterogeneous contribution to the catalytic activity of at least 15% can be estimated. Metal leaching is extremely low and depends on the catalyst preparation mode. The catalysts were employed batchwise in up to 60 reactions exceeding an application period of 50 days. Based on these results catalyst lifetimes of approximately 1500 days can be expected. They were applied without any reconditioning and loss of activity thus offering promising perspectives for industrial applications in continuously operating processes.
Alkyl‐ and Arylthiolation of Aryl Halides Catalyzed by Fluorinated Bis‐Imino‐Nickel NNN Pincer Complexes [NiCl2{C5H3N‐2,6‐(CHNArf)2}]
Authors: Baldovino‐Pantaleón Oscar , Hernández‐Ortega Simón , Morales‐Morales David 
Published: January 2006

AbstractThe synthesis of bis‐imino nickel(II) NNN pincer complexes of the type [NiCl2{C5H3N‐2,6‐(CHNArf)2}]; Arf=C6H3‐2,3‐F2 (1), C6H3‐2,5‐F2 (2), C6H3‐3,4‐F2 (3), C6H3‐3,5‐F2 (4), C6H2‐2,3,4‐F3 (5), C6H2‐2,3,6‐F3 (6), C6H2‐2,4,5‐F3 (7), C6H2‐2,4,6‐F3 (8), has been achieved and their reactivity in alkyl‐ and arylthiolation reactions of halobenzenes examined. The use of fluorinated substituents Arf on the imines has allowed the tuning of the electronics in these complexes and the influence of these substituents and those of the disulfides in the thiolation reactions have been analyzed.
Proazaphosphatrane P(RNCH2CH2)3N (R=Me, i‐Pr)‐Catalyzed Isomerization of Allylaromatics, Allyl Phenyl Sulfide, Allyl Phenyl Sulfone, and bis‐Allylmethylene Double Bond‐Containing Compounds
Authors: Yu Zhengkun , Yan Shenggang , Zhang Guangtao , He Wei , Wang Liandi , Li Yu , Zeng Fanlong 
Published: January 2006

AbstractUsing a proazaphosphatrane catalyst, P(RNCH2CH2)3N (R=Me, i‐Pr), allylaromatics and allyl phenyl sulfide were selectively isomerized to the corresponding vinyl isomers in yields up to >99% in CH3CN at 40 °C. Efficient transformation of allyl phenyl sulfone at ambient temperature afforded an isomerization/dimerization product in >95% yield. Conjugation of bis‐allylmethylene double bond‐containing compounds gave the corresponding conjugated isomers for cis,cis‐9,12‐octadecadienol and its methyl ether in yields up to 97%, and desilylation/conjugation products were obtained from the catalytic reaction of the trimethylsilyl ether of cis,cis‐9,12‐octadecadienol. The reaction mechanism is discussed based upon the 1H and 31P NMR‐monitored reactions in CD3CN or CH3CN under the reaction conditions.
Supported Ionic Liquids. New Recyclable Materials for the L‐Proline‐Catalyzed Aldol Reaction
Authors: Gruttadauria Michelangelo , Riela Serena , Aprile Carmela , Meo Paolo Lo , D'Anna Francesca , Noto Renato 
Published: January 2006

AbstractNew materials for L‐proline recycling have been developed. These materials have been applied to the L‐proline‐catalyzed aldol reaction between acetone and several aldehydes. The L‐proline has been supported on the surface of modified silica gels with a monolayer of covalently attached ionic liquid with or without additional adsorbed ionic liquid. Good yields and ee values, comparable with those obtained under homogeneous conditions, have been obtained especially with imidazolinium‐modified and 4‐methylpyridinium‐modified silica gels. Moreover, these materials have been easily recovered by simple filtration and studies about their reuse have been carried out. These studies showed that these materials can be used at least up to seven times. Finally, in the case of imidazolinium‐modified silica gel, investigations showed that this support can be regenerated giving again a recyclable material with high isolated yields and reproducible ee values up to 13 cycles.
Synthesis of Aryl‐Substituted 1,4‐Benzoquinone via Water‐Promoted and In(OTf)3‐Catalyzed in situ Conjugate Addition‐Dehydrogenation of Aromatic Compounds to 1,4‐Benzoquinone in Water
Authors: Zhang Hai‐Bo , Liu Li , Chen Yong‐Jun , Wang Dong , Li Chao‐Jun 
Published: January 2006

AbstractMono‐ and diaryl‐substituted 1,4‐quinones were synthesized by the In(OTf)3‐catalyzed conjugate addition of aromatic C‐nucleophiles to 1,4‐quinone derivatives followed by in situ dehydrogenation in water. Water was found to be beneficial to the reaction. The regioselectivity of the addition reaction in water was also examined.
Self‐Promoted Nucleophilic Addition of Hexafluoro‐2‐propanol to Vinyl Ethers
Authors: Di Salvo Andrea , David Marc , Crousse Benoît , Bonnet‐Delpon Danièle 
Published: January 2006

AbstractIn spite of its low nucleophilicity, hexafluoro‐2‐propanol easily adds to vinyl ethers, without catalyst, to afford a range of hexafluoroisopropyloxy acetals. This addition reaction also occurred in the presence of a competitive, more nucleophilic alcohol. Kinetic studies showed the importance of hydrogen bond parameters in the rate and course of the reaction.
Conversion of Amines to Imines Employing Polymer‐Supported Sulfoxide (PSS) and Polymer‐Supported Perruthenate (PSP): Synthesis of Pyrrolo[2,1‐c][1,4]benzodiazepines
Authors: Kamal Ahmed , Devaiah V. , Reddy K. Laxma , Shankaraiah N. 
Published: January 2006

AbstractAn efficient method for the oxidation of secondary amines to the corresponding imines has been developed by employing polymer‐supported reagents. This protocol has been extended for the generation of a combinatorial library of substituted pyrrolo[2,1‐c][1,4]benzodiazepine derivatives and provides a rapid and clean preparation avoiding conventional purification techniques.
Chiral Diphosphine ddppm‐Iridium Complexes: Effective Asymmetric Imine Hydrogenations at Ambient Pressures
Authors: Dervisi Athanasia , Carcedo Cristina , Ooi Li‐ling 
Published: January 2006

AbstractComplexes of the type [Ir(ddppm)(COD)]X were prepared and tested in the asymmetric hydrogenation of a range of imine substrates. Contrary to known iridium catalysts, the ddppm complexes formed efficient catalysts under an atmospheric hydrogen pressure, whereas at higher pressures the catalytic activity of the system was drastically reduced. Depending upon the reaction conditions, N‐arylimines, Ar′NCMeAr, were hydrogenated to the corresponding secondary amines in high yields and enantioselectivities (80–94% ee). In contrast to the [BF4]− and [PF6]− complexes, coordinating anions such as chloride did not form active Ir‐ddppm hydrogenation catalysts. The cationic Ir‐ddppm hydrogenation system performed well in chlorinated solvents, whereas coordinating solvents deactivated the system. Dimeric and trimeric Ir(III) polyhydride complexes were formed from the reaction of [Ir(ddppm)(COD)]PF6 with molecular hydrogen at atmospheric pressure and were found to inhibit catalytic activity.
Rhodium‐Catalyzed Hydrosilylation of Internal Alkynes with Silane Reagents bearing Heteroatom Substituents. Studies on the Regio‐/Stereochemistry and Transformation of the Produced Alkenylsilanes by Rhodium‐Catalyzed Conjugate Addition
Authors: Sanada Tomoyuki , Kato Tsuyoshi , Mitani Makoto , Mori Atsunori 
Published: January 2006

AbstractRhodium‐catalyzed hydrosilylation of internal alkynes furnished (E)‐1,2‐disubstituted alkenylsilanes. The obtained alkenylsilane was subjected to reaction with α,β‐unsaturated carbonyl compounds in the presence of a rhodium catalyst to undergo conjugate addition. One‐pot hydrosilylation‐conjugate addition with a rhodium catalyst was also performed.
A Simple and Practical Method for the Preparation and Purity Determination of Halide‐Free Imidazolium Ionic Liquids
Authors: Cassol Claúdia C. , Ebeling Günter , Ferrera Bauer , Dupont Jairton 
Published: January 2006

AbstractThe reaction of N‐alkylimidazole with alkyl sulfonates at room temperature affords 1,3‐dialkylimidazolium alkanesulfonates as crystalline solids in high yields. The alkanesulfonate anions can be easily substituted by a series of other anions [BF4, PF6, PF3(CF2CF3)3, CF3SO3 and N(CF3SO2)2] by simple reaction of anions, salts, or acids in water at room temperature. Extraction with dichloromethane, filtration through a short basic alumina column and solvent evaporation affords the desired ionic liquids in 80–95% yield. The purity (>99.4%) of these ionic liquids can be determined by 1H NMR spectra using the intensity of the 13C satellites of the imidazolium N‐methyl group as internal standard.
Amino Acid‐Catalyzed Asymmetric Carbohydrate Formation: Organocatalytic One‐Step De Novo Synthesis of Keto and Amino Sugars
Authors: Ibrahem Ismail , Zou Weibiao , Xu Yongmei , Córdova Armando 
Published: January 2006

AbstractA direct de novo synthesis of ketoses and amino sugars by amino acid‐catalyzed asymmetric aldol, Mannich and Michael reactions with dihydroxyacetone phosphate mimics as donors is presented. Proline, proline derivatives and thiazolidine‐4‐carboxylic acids catalyzed the asymmetric assembly of keto sugars and amino sugars in high yield with up to >99% ee. The organocatalytic C3+Cn methodology presented herein is a direct entry to the de novo synthesis of orthogonally protected C4, C5, and C6 ketoses, carbohydrate derivatives, amino and aza sugars and the total synthesis of polyoxamic acids. The addition of water significantly accelerated and improved the enantioselectivity of the proline‐mediated biomimetic asymmetric CC bond‐forming reactions.
Appraisal of traditional and recently proposed relationships between the hard and soft dimensions of the nose in profile
Authors: Rynn Christopher , Wilkinson Caroline M. 
Published: January 2006

AbstractThis paper tests six methods of predicting external nasal profile proportions, using the form and dimensions of the bony nasal (piriform) aperture. A sample of 122 lateral cephalograms was measured and traced before each method was attempted, under blind conditions where appropriate. Error was assessed by comparing predicted to actual proportions. Methods used by the following authors were tested: Krogman and Iscan (1986 The Human Skeleton in Forensic Medicine, Springfield: C.C. Thomas), Gerasimov (1955 The Reconstruction of the Face on the Skull), Prokopec and Ubelaker (2002 Forensic Sci. Commun. 4:1–4), Macho (1986 J. Forensic Sci. 31:1391–1403), George (1987 J. Forensic Sci. 32:1305–1330), and Stephan et al. (2003 Am J. Phys. Anthropol. 122:240–250). The two‐tangent method by Gerasimov (1955 The Reconstruction of the Face on the Skull) was found to perform best at predicting a point on the nasal tip on male and female preoperative subjects. The method of Krogman and Iscan (1986 The Human Skeleton in Forensic Medicine, Springfield: C.C. Thomas) performed poorly, as did the nasal profile determination method (Prokopec and Ubelaker 2002 Forensic Sci. Commun. 4:1–4). The other methods, all derived by a process of regression calculations, were shown to perform with variable accuracy on this sample, despite the age range and ethnicity of this sample closely resembling that of the samples from which these methods were derived. Am J Phys Anthropol, 2006. © 2006 Wiley‐Liss, Inc.
Revision of the Fully technique for estimating statures
Authors: Raxter Michelle H. , Auerbach Benjamin M. , Ruff Christopher B. 
Published: January 2006

AbstractThe “anatomical” method of Fully (1956 Ann. Legale Med. 35:266–273) for reconstructing stature, involving the addition of skeletal elements from the calcaneus to the skull, has been increasingly used in anthropological and forensic contexts, but has undergone little systematic testing on samples other than the original sample used to develop the technique. The original description by Fully of the method also does not provide completely explicit directions for taking all of the necessary measurements. This study tested the accuracy and applicability of his method, and clarified measurement procedures. The study sample consisted of 119 adult black and white males and females of known cadaveric statures from the Terry Collection. Cadaveric statures were adjusted to living statures, following the recommendations of Trotter and Gleser (1952 Am. J. Phys. Anthropol. 10:469–514). We obtained the best results using maximum vertebral body heights (anterior to the pedicles) and measurement of the articulated talus and calcaneus height in anatomical position. Statures derived using the original Fully technique are strongly correlated with living statures in our sample (r = 0.96), but underestimate living stature by an average of about 2.4 cm. Anatomical considerations also suggest that the correction factors applied by Fully to convert summed skeletal height to living stature are too small. New formulae are derived to calculate living stature from skeletal height. There is no effect of sex or ancestry on stature prediction. Resulting stature estimates are accurate to within 4.5 cm in 95% of the individuals in our sample, with no directional bias. Am J Phys Anthropol, 2006. © 2006 Wiley‐Liss, Inc.
Who's afraid of the big bad Wolff?: “Wolff's law” and bone functional adaptation
Authors: Ruff Christopher , Holt Brigitte , Trinkaus Erik 
Published: January 2006

Abstract“Wolff's law” is a concept that has sometimes been misrepresented, and frequently misunderstood, in the anthropological literature. Although it was originally formulated in a strict mathematical sense that has since been discredited, the more general concept of “bone functional adaptation” to mechanical loading (a designation that should probably replace “Wolff's law”) is supported by much experimental and observational data. Objections raised to earlier studies of bone functional adaptation have largely been addressed by more recent and better‐controlled studies. While the bone morphological response to mechanical strains is reduced in adults relative to juveniles, claims that adult morphology reflects only juvenile loadings are greatly exaggerated. Similarly, while there are important genetic influences on bone development and on the nature of bone's response to mechanical loading, variations in loadings themselves are equally if not more important in determining variations in morphology, especially in comparisons between closely related individuals or species. The correspondence between bone strain patterns and bone structure is variable, depending on skeletal location and the general mechanical environment (e.g., distal vs. proximal limb elements, cursorial vs. noncursorial animals), so that mechanical/behavioral inferences based on structure alone should be limited to corresponding skeletal regions and animals with similar basic mechanical designs. Within such comparisons, traditional geometric parameters (such as second moments of area and section moduli) still give the best available estimates of in vivo mechanical competence. Thus, when employed with appropriate caution, these features may be used to reconstruct mechanical loadings and behavioral differences within and between past populations. Am J Phys Anthropol, 2006. © 2006 Wiley‐Liss, Inc.