bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analytical potential energy functions and theoretical spectroscopic constants for MX/MX− (MGe, Sn, Pb; XO, S, Se, Te, Po) and LuA (AH, F) systems: Density functional theory calculations
Authors: Jalbout Abraham F. , Li Xin‐Hua , Abou‐Rachid Hakima 
Published: October 2006

AbstractThe molecular spectroscopic constants for the chalcogenide complexes MX (MGe, Sn, Pb; XO, S, Se, Te, Po) and their corresponding MX− anions are presented with the LSDA/SDD, B1LYP/SDD, and B3LYP/SDD methods. Although many methods were attempted, only the most promising results are reported. We show that the best results are obtained by LSDA/SDD calculations, and thus this method is emphasized as an illustrative example of our methodology. The potential energy curves and physical property characterizations for X1 ∑+ state of LuH and LuF are presented with a variety of density functional theory (DFT) methods. Comparisons with wave function‐based treatments (HF, MP2, CCSD, QCISD) are made in addition to experimental correlations. We show that the best results are obtained by the B3LYP/SDD method for LuH, and the MPW1PW91/SDD method for LuF. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Theoretical study of electrical and electrochemical properties of cyclopentanepentaone and its dicyanomethylene derivatives
Authors: Xue Zhao‐Ming , Chen Chun‐Hua 
Published: October 2006

AbstractTheoretical studies on anions of 1,2‐dihydroxycyclopentenetrione (croconic acid, H2C5O5) and the whole series of dicyanomethylene derivatives in gas phase and in dimethyl formamide (DMF) solution are carried out using density functional theory (DFT) and self‐consistent reaction field (SCRF)‐DFT method at the B3LYP theory level for the first time. Natural bond orbital (NBO) analyses indicate that π‐electron delocalization in the series is quite strong. Based on the most stable conformations, linear correlations are observed between the oxidation potential measured by cyclic voltammetry and the highest occupied molecular orbital (HOMO) energy as well as ionization potential (Ip), which supports experimental results that systematic substitution of the oxygen atoms in the C5O structure with C(CN)2 groups causes a shift of both the oxidation potentials E and E toward more positive values. The correlations are also observed between experimental diffusion coefficient D and Ebind calculated in gas phase and DMF solution, the experimental electrochemical reducing potentials (ER) and the electron affinity (Ea). © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Atmospheric‐pressure Penning ionization of aliphatic hydrocarbons
Authors: Hiraoka Kenzo , Furuya Hiroko , Kambara Shizuka , Suzuki Shigeo , Hashimoto Yutaka , Takamizawa Atsushi 
Published: October 2006

AbstractA study has been made of the atmospheric‐pressure Penning ionization (APPeI) of aliphatic hydrocarbons (pentane, hexane, heptane, and octane) with long‐lived rare gas atoms (Rg*). The metastable rare gas atoms (He*, Ne*, Ar* and Kr*) were generated by the negative‐mode corona discharge of atmospheric‐pressure rare gases. In the Rg*APPeI mass spectra for aliphatic hyrocarbons, the relative abundances of fragment ions were found to increase in the order of He* → Ne* → Ar* → Kr*. The order is in the opposite direction to the internal energies of the Rg*. The less fragmentation observed for He* may be because the nascent molecular ions [M+.]* formed by Penning ionization have lifetimes long enough for them to be collisionally deactivated in the atmospheric‐pressure ion source. It was found that the relative abundances of fragment ions in Ar*APPeI increased when the sample pressure in the ion source was reduced. This is attributed to the collision of Ar* with molecular ions followed by fragmentation. Copyright © 2006 John Wiley & Sons, Ltd.
Electrospray ionization from a gap with adjustable width
Authors: Ek Patrik , Sjödahl Johan , Roeraade Johan 
Published: October 2006

AbstractIn this paper, we present a new concept for electrospray ionization mass spectrometry, where the sample is applied in a gap which is formed between the edges of two triangular‐shaped tips. The size of the spray orifice can be changed by varying the gap width. The tips were fabricated from polyethylene terephthalate film with a thickness of 36 µm. To improve the wetting of the gap and sample confinement, the edges of the tips forming the gap were hydrophilized by means of silicon dioxide deposition. Electrospray was performed with gap widths between 1 and 36 µm and flow rates down to 75 nL/min. The gap width could be adjusted in situ during the mass spectrometry experiments and nozzle clogging could be managed by simply widening the gap. Using angiotensin I as analyte, the signal‐to‐noise ratio increased as the gap width was decreased, and a shift towards higher charge states was observed. The detection limit for angiotensin I was in the low nM range. Copyright © 2006 John Wiley & Sons, Ltd.
Usefulness of an integrated microfluidic device (HPLC‐Chip‐MS) to enhance confidence in protein identification by proteomics
Authors: Hardouin Julie , Duchateau Magalie , Joubert‐Caron Raymonde , Caron Michel 
Published: October 2006

AbstractNanoflow liquid chromatography/mass spectrometry (nanoLC/MS) has become a current tool in proteomics applications increasingly used in the search for new biomarkers. A new integrated microfluidic device (HPLC‐Chip), coupled to ion trap mass spectrometry (ITMS), appears as an innovative and robust tool for improving the identifications commonly performed by nanoLC/MS/MS. We tested this device for the identification of proteins obtained from two‐dimensional gel electrophoresis or chromatography. The chip allows the measurement of reproducible retention times that, in association with m/z ratios, was found useful for identifying peptide sequences without ambiguity. A sensitivity increase of a factor of at least 5‐fold is obtained compared to the results obtained previously in our laboratory by conventional nanoLC/MS/MS on the same ion trap. We conclude that this recently available microfluidic device can be a valuable tool during biomarker discovery programs, particularly identifying low‐abundance proteins. Copyright © 2006 John Wiley & Sons, Ltd.
Identification of sources and production processes of bottled waters by stable hydrogen and oxygen isotope ratios
Authors: Brencic Mihael , Vreca Polona 
Published: October 2006

AbstractBottled water is a food product that considerably depends on the environment from which it originates, not only at the place where it is produced, but predominantly on the conditions in the recharge area of the wells captured for bottling. According to their source and the bottling process, bottled waters can be divided into natural and artificially sparkling waters, still and flavoured waters. These waters originate from various parts of the hydrological cycle and their natural origin is reflected in their hydrogen and oxygen stable isotopic compositions (δ2H and δ18O). A total of 58 domestic and foreign brands and 16 replicates of bottled waters, randomly collected on the Slovene market in September 2004, were analysed for δ2H and δ18O. The isotopic composition varied between −83‰ and −46‰ with an average of −66‰ for hydrogen, and between −11.9‰ and −7.5‰ with an average of −9.6‰ for oxygen. This investigation helped (1) to determine and test the classification of bottled waters, (2) to determine the natural origin of bottled water, and (3) to indicate differences between the natural and production processes. The production process may influence the isotopic composition of flavoured waters and artificially sparkling waters. No such modification was observed for still and natural sparkling waters. The methods applied, together with hydrological knowledge, can be used for the authentication of bottled waters for regulatory and consumer control applications. Copyright © 2006 John Wiley & Sons, Ltd.
On fractional K‐factors of random graphs
Authors: Haber Simi , Krivelevich Michael 
Published: October 2006

AbstractLet K be a graph on r vertices and let G = (V,E) be another graph on ∣V ∣ = n vertices. Denote the set of all copies of K in G by 𝒦. A non‐negative real‐valued function f : 𝒦→ ℝ+ is called a fractional K‐factor if ∑ K:v∈K∈𝒦f(K) ≤ 1 for every v ∈ V and ∑ K∈𝒦f(K) = n/r. For a non‐empty graph K let d(K) = e(K)/v(K) and d(1)(K) = e(K)/(v(K) ‐ 1). We say that K is strictly K1‐balanced if for every proper subgraph K′ ⊊ K, d(1)(K′) < d(1)(K). We say that K is imbalanced if it has a subgraph K′ such that d(K′) > d(K). Considering a random graph process
$\widetilde{G}$
on n vertices, we show that if K is strictly K1‐balanced, then with probability tending to 1 as n →∞, at the first moment τ0 when every vertex is covered by a copy of K, the graph ${\widetilde{G}}_{\tau_0}$
has a fractional K‐factor. This result is the best possible. As a consequence, if K is K1‐balanced, we derive the threshold probability function for a random graph to have a fractional K‐factor. On the other hand, we show that if K is an imbalanced graph, then for asymptotically almost every graph process there is a gap between τ0 and the appearance of a fractional K‐factor. We also introduce and apply a criteria for perfect fractional matchings in hypergraphs in terms of expansion properties. © 2006 Wiley Periodicals, Inc. Random Struct. Alg., 2007
Summary of ISO/TC 201 Standard: XXIII, ISO 24236:2005—surface chemical analysis—Auger electron spectroscopy—repeatability and constancy of intensity scale
Authors: Seah M. P. 
Published: October 2006

AbstractThis International Standard specifies a method for evaluating the constancy and repeatability of the intensity scale of Auger electron spectrometers, for general analytical purposes, using an electron gun with a beam energy of 2 keV or greater. It is only applicable to instruments that incorporate an ion gun for sputter cleaning. It is not intended to be a calibration of the intensity/energy response function.1,2 That calibration may be made by the instrument manufacturer or other organization. The present procedure provides data to evaluate and confirm the accuracy with which the intensity/energy response function remains constant with instrument usage. Guidance is given to some of the instrumental settings that may affect this constancy. © Crown Copyright 2006. Reproduced with the permission of the Controller of HMSO.
Synthesis, Structure, and Spectroscopic Properties of Octa(iso‐pentoxy)phthalocyaninatometal Complexes
Authors: Lin Mei‐Jin , Wang Jun‐Dong , Chen Nai‐Sheng , Huang Jin‐Ling 
Published: October 2006

AbstractA series of octa‐substituted metal phthalocyanines [MPc(OC5H11)8] (M = Co, Ni, Cu, Zn, Pc = phthalocyaninato, (OC5H11)8 = iso‐pentoxy) were obtained from condensation of iso‐pentoxy phthalonitrile in the presence of DBU in n‐pentanol. The compounds were characterized using elemental analysis, IR, and UV/Vis spectra. The crystal structures of all compounds except M = Zn were determined by X‐ray diffraction methods. It was found that the distortion of Pc skeleton come of not only the intra‐molecular steric congestion of bulky substituents, but also the slipped overlaps of the closest molecules. The relations of some bond lengths of the Pc's skeleton to the substituents and central metal atom, as well as the spectroscopic properties are discussed.
The Elusive Tetrasamarium‐oxide‐hexabromide, Sm4OBr6
Authors: Hammerich Stefanie , Pantenburg Ingo , Meyer Gerd 
Published: October 2006

AbstractBlack single crystals of tetrasamarium(II)‐oxide‐hexabromide, Sm4OBr6, were obtained from a reaction of SmBr3, Sm2O3 and Na in a sealed tantalum container at 750 °C. Sm4OBr6 crystallizes in the hexagonal space group P63mc (Z = 2, a = 985.89(9), c = 753.50(6) pm, R = 0.035 for all data) as do all M4OX6 type oxide halides with M = Ca,Sr,Ba,Eu,Sm,Yb and X = Cl,Br,I, as far as they have been obtained. The crystal structure is also the anti‐type of K6HgS4/Na6ZnO4 with K6HgS4 = Br6OSm4. The {OSm4} tetrahedron is surrounded by 18 bromide ligands according to {OSm2Sm13}(μ1‐Br16)(μ1‐Br23)(μ2‐Br13)(μ2‐Br23)(μ3‐Br23). These bromide ligands bridge to other such tetrahedra to allow for a three‐dimensional structure.
Dimeric Sandwich‐like Ion Pairs in the Crystal Structure of Tetrabutylammonium Ozonide Ammoniate
Authors: Dietzel Pascal D. C. , Jansen Martin 
Published: October 2006

AbstractThe novel ionic ozonide {[N(C4H9)4](O3)}4·4.75NH3 was synthesized by ion‐exchange reaction in liquid ammonia. The crystal structure was determined by single crystal diffraction at 100 K (monoclinic space group P21, a = 15.014(11) Å, b = 13.696(10) Å, c = 19.890(15) Å, β = 105.407(12)°, V = 3943(5) Å3, Z = 2). The structure consists of a packing of sandwich‐like dimeric ion pairs in which two ozonide anions are interspersed between two tetrabutylammonium cations. Ammonia molecules from the solvent are localized in cavities in the structure. They are involved in hydrogen bonding with the ozonide ions. The desolvated tetrabutylammonium ozonide forms stable solutions in dichloromethane which may open up novel possibilities of tapping into the synthetic potential of the ozonide ion.
Synthesis, Characterization, and Crystal Structure of a Chromium(III)‐Complex Containing 2,6‐Pyridinedicarboxylic Acid and 1,10‐Phenanthroline
Authors: Rafizadeh Masoud , Amani Vahid , Neumüller Bernhard 
Published: October 2006

AbstractThe reaction of solution 2,6‐pyridinedicarboxylic acid and 1,10‐phenanthroline (1) with CrCl3·6H2O led to the complex [Cr(phen)(pydc)(H2O)][Cr(pydc)2]·4H2O (2) (phen is 1,10‐phenanthroline and pydcH2 is 2,6‐pyridinedicarboxylic acid). 2 was characterized by elemental analysis, IR spectroscopy and single‐crystal structure determination. Crystal data for 2 at −80 °C: triclinic, space group ${\rm P}{\bar 1}$, a = 818.5(1), b = 1492.2(1), c = 1533.6(2) pm, α = 76.45(1)°, β = 84.22(1)°, γ = 77.99(1)°, Z = 2, R1 = 0.0416.
Pyridylmethylamines as Ligands in Iron Halide Complexes – Coordination Behaviour Depending on the Halide, the Denticity of the Amino Ligand and the Oxidation State of Iron
Authors: Malassa Astrid , Görls Helmar , Buchholz Axel , Plass Winfried , Westerhausen Matthias 
Published: October 2006

Abstract2‐Pyridylmethylamine (amp) and 8‐aminochinoline (ach) readily form the following complexes with iron halides in methanol: [(amp)2FeCl2] (1a), [(amp)2FeBr2] (1b), [(ach)2Fe(MeOH)2]Br2 (1c), and [(amp)FeCl2(μ‐OMe)]2 (2). Methanol was chosen as a solvent because these reactions are rather complex in ether. For example, FeCl3 forms the ionic complex pair [(dme)2FeCl2] [FeCl4] (3) with 1,2‐dimethoxyethane (dme). The reaction of FeBr2 with tridentate di(2‐pyridylmethyl)amine (dpa) and tetradentate 1,2‐dipyridyl‐1,2‐diaminoethane (dpdae) yields the complexes [(dpa)2Fe]Br2·2 MeOH (4) and [(dpdae)2Fe] [FeBr4] (5), respectively. Crystallographic and magnetochemical investigations show the high‐spin configuration for the complexes 1 and 2, whereas the short Fe‐N distances of 4 clearly indicate a low‐spin state. Compound 2 exhibits an antiferromagnetic exchange interaction with a coupling constant J = −29.4 cm−1 (H;af = −J S;afA·S;afB).
Further reviews
Authors: Palmer Peter 
Published: October 2006

FRITZ BRUN: Symphony No. 9; Aus dem Buch Hiob (Symphonische Dichtung). Moscow Symphony Orchestra c. Adriano. Guild GMCD 7306.SCHOECK: String Quartet No. 2 in C major. FRITZ BRUN: String Quartet No. 3 in F major. Amar Quartett. Musiques Suisses MGB CD 6238.HANS SCHAEUBLE: String Quartet op.19. MEINRAD SCHÜTTER: String Quartet. ERICH SCHMID: String Quartet op. 4. casalQUARTETT Zurich. Guild GMCD 7303.
Structure-guided design of a novel class of benzyl-sulfonate inhibitors for influenza virus neuraminidase
Authors: Platis Dimitris , Smith Brian J. , Huyton Trevor , Labrou Nikolaos E. 
Published: October 2006

Influenza NA (neuraminidase) is an antiviral target of high pharmaceutical interest because of its essential role in cleaving sialic acid residues from cell surface glycoproteins and facilitating release of virions from infected cells. The present paper describes the use of structural information in the progressive design from a lead binding ion (a sulfate) to a potent submicromolor inhibitor (Ki 0.13 μM). Structural information derived from the X-ray structure of an NA complexed with several sulfate ions, in combination with results derived from affinity labelling and molecular modelling studies, was used to guide design of potent sulfonic acid-based inhibitors. These inhibitors are structural fragments of the polysulfonate triazine dye Cibacron Blue 3GA and represent novel lead scaffolds for designing non-carbohydrate inhibitors for influenza neuraminidases.
Hepatocyte nuclear factor-4α contributes to carbohydrate-induced transcriptional activation of hepatic fatty acid synthase
Authors: Adamson Aaron W. , Suchankova Gabriela , Rufo Caterina , Nakamura Manabu T. , Teran-Garcia Margarita , Clarke Steven D. , Gettys Thomas W. 
Published: October 2006

Refeeding a carbohydrate-rich meal after a fast produces a co-ordinated induction of key glycolytic and lipogenic genes in the liver. The transcriptional response is mediated by insulin and increased glucose oxidation, and both signals are necessary for optimal induction of FAS (fatty acid synthase). The glucose-regulated component of FAS promoter activation is mediated in part by ChREBP [ChoRE (carbohydrate response element)-binding protein], which binds to a ChoRE between −7300 and −7000 base-pairs in a carbohydrate-dependent manner. Using in vivo footprinting with nuclei from fasted and refed rats, we identify an imperfect DR-1 (direct repeat-1) element between −7110 and −7090 bp that is protected upon carbohydrate refeeding. Electrophoretic mobility-shift assays establish that this DR-1 element binds HNF-4α (hepatocyte nuclear factor 4α), and chromatin immunoprecipitation establishes that HNF-4α binding to this site is increased approx. 3-fold by glucose refeeding. HNF-4α transactivates reporter constructs containing the distal FAS promoter in a DR-1-dependent manner, and this DR-1 is required for full glucose induction of the FAS promoter in primary hepatocytes. In addition, a 3-fold knockdown of hepatocyte HNF-4α by small interfering RNA produces a corresponding decrease in FAS gene induction by glucose. Co-immunoprecipitation experiments demonstrate a physical interaction between HNF-4α and ChREBP in primary hepatocytes, further supporting an important complementary role for HNF-4α in glucose-induced activation of FAS transcription. Taken together, these observations establish for the first time that HNF-4α functions in vivo through a DR-1 element in the distal FAS promoter to enhance gene transcription following refeeding of glucose to fasted rats. The findings support the broader view that HNF-4α is an integral component of the hepatic nutrient sensing system that co-ordinates transcriptional responses to transitions between nutritional states.
Increased protein glycation in fructosamine 3-kinase-deficient mice
Authors: da-Cunha Maria VEIGA , Jacquemin Patrick , Delpierre Ghislain , Godfraind Catherine , Théate Ivan , Vertommen Didier , Clotman Frédéric , Lemaigre Frédéric , Devuyst Olivier , Van Schaftingen Emile 
Published: October 2006

Amines, including those present on proteins, spontaneously react with glucose to form fructosamines in a reaction known as glycation. In the present paper, we have explored, through a targeted gene inactivation approach, the role of FN3K (fructosamine 3-kinase), an intracellular enzyme that phosphorylates free and protein-bound fructose-ϵ-lysines and which is potentially involved in protein repair. Fn3k−/− mice looked healthy and had normal blood glucose and serum fructosamine levels. However, their level of haemoglobin-bound fructosamines was approx. 2.5-fold higher than that of control (Fn3k+/+) or Fn3k+/− mice. Other intracellular proteins were also significantly more glycated in Fn3k−/− mice in erythrocytes (1.8–2.2-fold) and in brain, kidney, liver and skeletal muscle (1.2–1.8-fold), indicating that FN3K removes fructosamines from intracellular proteins in vivo. The urinary excretion of free fructose-ϵ-lysine was 10–20-fold higher in fed mice compared with mice starved for 36 h, and did not differ between fed Fn3k+/+ and Fn3k−/− mice, indicating that food is the main source of urinary fructose-ϵ-lysine in these mice and that FN3K does not participate in the metabolism of food-derived fructose-ϵ-lysine. However, in starved animals, the urinary excretion of fructose-ϵ-lysine was 2.5-fold higher in Fn3k−/− mice compared with Fn3k+/+ or Fn3k+/− mice. Furthermore, a marked increase (5–13-fold) was observed in the concentration of free fructose-ϵ-lysine in tissues of fed Fn3k−/− mice compared with control mice, indicating that FN3K participates in the metabolism of endogenously produced fructose-ϵ-lysine. Taken together, these data indicate that FN3K serves as a protein repair enzyme and also in the metabolism of endogenously produced free fructose-ϵ-lysine.
Aldolase potentiates DIDS activation of the ryanodine receptor in rabbit skeletal sarcoplasmic reticulum
Authors: Seo In-Ra , Moh Sang Hyun , Lee Eun Hui , Meissner Gerhard , Kim Do Han 
Published: October 2006

DIDS (4,4′-di-isothiocyanostilbene-2,2′-disulfonate), an anion channel blocker, triggers Ca2+ release from skeletal muscle SR (sarcoplasmic reticulum). The present study characterized the effects of DIDS on rabbit skeletal single Ca2+-release channel/RyR1 (ryanodine receptor type 1) incorporated into a planar lipid bilayer. When junctional SR vesicles were used for channel incorporation (native RyR1), DIDS increased the mean Po (open probability) of RyR1 without affecting unitary conductance when Cs+ was used as the charge carrier. Lifetime analysis of single RyR1 activities showed that 10 μM DIDS induced reversible long-lived open events (Po=0.451±0.038) in the presence of 10 μM Ca2+, due mainly to a new third component for both open and closed time constants. However, when purified RyR1 was examined in the same condition, 10 μM DIDS became considerably less potent (Po=0.206±0.025), although the caffeine response was similar between native and purified RyR1. Hence we postulated that a DIDS-binding protein, essential for the DIDS sensitivity of RyR1, was lost during RyR1 purification. DIDS-affinity column chromatography of solubilized junctional SR, and MALDI–TOF (matrix-assisted laser-desorption ionization–time-of-flight) MS analysis of the affinity-column-associated proteins, identified four major DIDS-binding proteins in the SR fraction. Among them, aldolase was the only protein that greatly potentiated DIDS sensitivity. The association between RyR1 and aldolase was further confirmed by co-immunoprecipitation and aldolase-affinity batch-column chromatography. Taken together, we conclude that aldolase is physically associated with RyR1 and could confer a considerable potentiation of the DIDS effect on RyR1.