bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural and NMR Studies of the Hexameric Copper(I) Complex with N‐n‐butyl‐N′‐ethoxycarbonyl‐thioureate
Authors: Boyd Sue E. , Healy Peter C. , Hope Gregory A. , Woods Ronald 
Published: June 2008

AbstractThe copper sulfide mineral flotation collector, N‐n‐butyl‐N′‐ethoxycarbonyl‐thiourea (H2bectu), and the 1:1 hexameric copper(I) thioureate complex, [Cu(Hbectu)]6, have been characterized by single crystal X‐ray diffraction. H2bectu crystallizes in the triclinic space group $\rm P{\bar 1}$ with a = 5.2754(4), b = 9.0042(7), c = 12.6030(9) Å, α = 80.528(6), β = 90.173(6), γ = 76.472(7)°. An intramolecular N‐H···O hydrogen bond between the thioamide proton and carbonyl oxygen forms a planar six‐membered ring in the central core of the molecule with C=O, C=S and C‐N bond lengths in accord with those reported for other N‐alkyl/aryl‐N′‐acyl‐thiourea compounds. [Cu(Hbectu)]6 crystallizes in the monoclinic space group C2/c with a = 23.269(5), b = 13.243(4), c = 23.037(7) Å, β = 91.81(2)° as discrete hexameric clusters disposed about a crystallographic centre of symmetry with a Cu6S6 core consisting of two Cu3S3 chair‐shaped rings linked by coordination of the deprotonated amide nitrogen atom to a copper atom in the adjacent ring. The six ligands assemble as a paddlewheel structure with the ethoxy and n‐butyl substituents packing in an alternating head to tail arrangement. Temperature dependent solution 1H NMR spectroscopic studies show that the hexameric structure of the complex is maintained in solution.
Zur Elektronenstruktur metallorganischer Komplexe der f‐Elemente. 68 Absorptions‐ sowie erstmalige lumineszenz‐ und Raman‐spektroskopische Polarisationsmessungen an einem orientierten metallorganischen Einkristall: Pr(C5Me4H)3
Authors: Amberger Hanns‐Dieter , Reddmann Hauke 
Published: June 2008

AbstractElectronic Structures of Organometallic Complexes of f Elements. 68 Absorption and First Luminescence and Raman Spectroscopic Polarization Measurements of an Oriented Organometallic Single Crystal: Pr(C5Me4H)3Optical polarization measurements of oriented single crystals of Pr(C5Me4H)3(1) were performed at room temperature. In order to separate “cold” and “hot” f‐f‐transitions and νC–H combination vibrations, the absorption spectra of KBr pellets of compound1and La(C5Me4H)3(2) were additionally recorded at ca. 77 K. To gather additional information about the wavefunctions of the crystal field (CF) states of complex1, a magnetic circular dichroism spectrum of1was recorded too. From the spectra obtained, a partial CF splitting pattern of1was derived, and simulated by fitting the free parameters of a phenomenological Hamiltonian, leading to a reduced r.m.s. deviation of 24.8 cm−1for 24 assignments. On the basis of these phenomenological CF parameters, the global CF strength experienced by the Pr3+central ion was estimated, and seems to be the largest one ever encountered in PrIIIchemistry. The obtained Slater parameter F2and the spin‐orbit coupling parameter ζ4fallow the insertion of compound1into empirical nephelauxetic and relativistic nephelauxetic series, respectively, of PrIIIcompounds. With its low F2value, complex1is the most covalent PrIIIcompound (considering only f electrons) found to date. The experimentally‐based non‐relativistic molecular orbital scheme (in the f range) of complex1was determined and compared with the results of a previous Xα‐SW calculation on the ψ trigonal planar model compound Pr(η5‐C5H5)3. In the framework of the search for “polarized” luminescence transitions, polarized Raman spectra of1were recorded too, and compared to the corresponding FIR and IR spectra run by means of pellets.
Zinc Hydrazides and Hydrazide‐Alkoxides with Cyclic and Acyclic Hydrazide Substituents
Authors: Jana Surajit , Fröhlich Roland , Mitzel Norbert W. 
Published: June 2008

AbstractThe tetrameric organometallic zinc hydrazides the {(RZn)4[NHN(CH2)n]4} (R = Me, Et, iPr and n = 5, 4) (1–6), were prepared by alkane elimination from dialkyl zinc solutions and the ring‐substituted hydrazine derivatives 1‐aminopiperidine and 1‐aminopyrrolidine at ambient temperature. They were characterized by NMR (1H, 13C) and IR spectroscopy, by mass spectrometry and by elemental analyses. The compounds form asymmetric aggregates, containing Zn4N8 cores. Zinc trisalkoxide‐monohydrazides can be prepared in one‐pot syntheses by reacting dialkylzinc solutions simultaneously with alcohols and hydrazines. Reactions of dimethylzinc with isopropanol and monomethylhydrazine or mono‐t‐butylhydrazine in 2:1:1.03 ratio resulted in the formation of [(MeZn)4(NHNHR)(OiPr)3] [R = Me (7), tBu (8)]. In a similar fashion, dialkylzinc compounds react with 1‐aminopiperidine and alcohol in 5:4:4 ratio to give {(RZn)4[NHN(CH2)5](OR′)3]} [R = Me, R′ = iPr (9); R = Et, R′ = Et (10), iPr (11)]. These compounds were characterized as the above compounds. The structures of compounds 8 and 9 were also determined by crystal structure analyses. These compounds show an unsymmetrical aggregation with a Zn4N2O3 cage structure, confirmed by spectroscopic methods in solution.
Two New Quaternary Thiophosphates with Pseudo One‐dimensional Structures: Syntheses and Crystal Structures of Cs3Sm[PS4]2 and Rb3Sm[PS4]2
Authors: Milot Susanne , Wu Yuandong , Näther Christian , Bensch Wolfgang , Klepp Kurt O. 
Published: June 2008

AbstractThe new thiophosphates Rb3Sm[PS4]2 and Cs3Sm[PS4]2 were obtained as pale yellow needles using an in‐situ formed thiophosphate flux. Rb3Sm[PS4]2 crystallizes in the space group P21 with a = 9.7061(19) Å, b = 6.7517(14) Å, c = 11.395(2) Å, β = 90.63(3)°, (Z = 2); Cs3Sm[PS4]2 in space group P21/n with a = 15.311(3) Å, b = 6.8762(14) Å, c = 15.352(3) Å, β = 99.49(3)°, (Z = 4). The crystal structures are characterized by the formation of complex anionic chains, $^{1}_{\infty}\rm \{(Sm[PS_{4}]_{2})^{3-}\}$ which run along the [010] direction in both structures. One of the two independent thiophosphate groups connects three Sm3+ cations to form an infinite zigzag like arrangement, while the other acts as a terminal ligand to one Sm3+ions. Such a μ3 or face‐grafting coordination mode of a [PS4]3− anion is not very common. The Sm3+ ions are in bicapped trigonal prismatic chalcogen coordination. The average Sm–S distances within the trigonal prisms are close to 2.88Å, while the bonds to the capping atoms are distinctly longer. The chains are chiral yet their symmetry is close to 21/m. In contrast to the rubidium compound, Cs3Sm[PS4]2 contains both enantiomorphs. In both structures the chains are arranged as a distorted hexagonal rod packing.
Autoxidation of Conjugated Linoleic Acid Methyl Ester in the Presence of α‐Tocopherol: The Hydroperoxide Pathway
Authors: Pajunen Taina I. , Johansson Mikael P. , Hase Tapio , Hopia Anu 
Published: June 2008

AbstractAutoxidation of conjugated linoleic acid (CLA) methyl ester follows at least partly Farmer's hydroperoxide theory. A mechanism for this hydroperoxide pathway has been proposed based on autoxidation of 9‐cis,11‐trans‐CLA methyl ester. This investigation aims at confirming and further clarifying the mechanism by analyzing the hydroperoxides produced from 10‐trans,12‐cis‐CLA methyl ester and by theoretical calculations. Five methyl hydroxyoctadecadienoates were isolated by HPLC and characterized by UV, GC‐MS, and 1D‐ and 2D‐NMR techniques. In addition, an HPLC method for the separation of the intact hydroperoxides was developed. The autoxidation of 10‐trans,12‐cis‐CLA methyl ester in the presence of high amount of α‐tocopherol (20%) was diastereoselective in favor of one geometric isomer, namely Me 9‐OOH‐10t,12c, and produced new positional isomers 10‐ and 14‐hydroperoxides (Me 10‐OOH‐11t,13t; Me 14‐OOH‐10t,12c; and Me 14‐OOH‐10t,12t). Importantly, one of these new isomers, which was characterized as an intact hydroperoxide, had an unusual cis,trans geometry where the cis double bond is adjacent to the hydroperoxyl‐bearing methine carbon. Further insight to the mechanism was provided by calculating the relative energies for different conformations of the precursor lipid, the allylic carbon–hydrogen bond dissociation enthalpies, and the spin distributions on the intermediate pentadienyl radicals. As a result, a better understanding of the isomeric distribution of the product hydroperoxides was achieved and a modified mechanism that accounts for these calculations is presented.
Accuracy of a heart failure diagnosis in administrative registers
Authors: Kümler Thomas , Gislason Gunnar Hilmar , Kirk Vibeke , Bay Morten , Nielsen Olav W. , Køber Lars , Torp‐Pedersen Christian 
Published: June 2008

AbstractBackground:The incidence of heart failure is frequently reported using hospital discharge diagnoses. The specificity of a diagnosis has been shown to be high but the sensitivity of a reported diagnosis is unknown.Purpose:To study the accuracy of a heart failure diagnosis reported to the Danish National Patient Registers during routine clinical work.Methods:The patient population consisted of 3644 consecutive patients admitted to all departments in one hospital. Diagnoses reported to the National Patient Register were recorded. A study team evaluated each patient independently of routine care, performed an echocardiogram and evaluated whether clinical symptoms of heart failure were present. Heart failure was defined in accordance with current ESC guidelines as symptoms of heart failure and evidence of cardiac dysfunction.Results:A registered diagnosis of heart failure (n=126) carried a specificity of 99% and a sensitivity of 29% for all patients. The positive predictive value was 81%, the negative predictive value 90%.Conclusion:The diagnosis of Heart Failure in the Danish National Registers is underreported, but very specific.
Neuroimaging studies of the early stages of psychosis: A critical review
Authors: Fusar-Poli Paolo , Allen Paul , McGuire Philip 
Published: June 2008

AbstractPsychiatric imaging, in particular functional imaging techniques such as functional magnetic resonance imaging (fMRI) are potentially powerful tools to explore the neurophysiological basis of the early stages of psychosis. Despite this impressive growth, neuroimaging has yet to become an established as diagnostic instrument this area, partly as a result of significant heterogeneity across the findings from research studies. The present review aims to: (i) assess the determinants of inconsistencies in the results from neuroimaging studies of the early stages of psychosis; and (ii) suggest approaches for future imaging research in this field that may reduce methodological differences between studies.
APPROXIMATION BY SEVERAL RATIONALS
Authors: SHPARLINSKI IGOR E. 
Published: June 2008

AbstractFollowing T. H. Chan, we consider the problem of approximation of a given rational fraction a/q by sums of several rational fractions a1/q1,…,an/qn with smaller denominators. We show that in the special cases of n=3 and n=4 and certain admissible ranges for the denominators q1,…,qn, one can improve a result of T. H. Chan by using a different approach.
Accidents and opportunities: a history of the radio echo-sounding of Antarctica, 1958–79
Authors: TURCHETTI SIMONE , DEAN KATRINA , NAYLOR SIMON , SIEGERT MARTIN 
Published: June 2008

AbstractThis paper explores the history of radio echo-sounding (RES), a technique of glaciological surveying that from the late 1960s has been used to examine Antarctica's sub-glacial morphology. Although the origins of RES can be traced back to two accidental findings, its development relied upon the establishment of new geopolitical conditions, which in the 1960s typified Antarctica as a continent devoted to scientific exploration. These conditions extended the influence of prominent glaciologists promoting RES and helped them gather sufficient support to test its efficiency. The organization and implementation of a large-scale research programme of RES in Antarctica followed these developments. The paper also examines the deployment of RES in Antarctic explorations, showing that its completion depended on the availability of technological systems of which RES was an integral part.
Molecular and morphological evidence for the occurrence of Anisakis sp. A (Nematoda, Anisakidae) in the Blainville's beaked whale Mesoplodon densirostris
Authors: Iglesias R. , D'Amelio S. , Ingrosso S. , Farjallah S. , Martínez-Cedeira J.A. , García-Estévez J.M. 
Published: June 2008

AbstractTwenty-three adults (only one male) and two fourth-stage larvae of Anisakis, recovered from the stomach of a Blainville's beaked whale (Mesoplodon densirostris) stranded in Galicia (NW Spain), were studied morphologically and molecularly. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequencing studies carried out on the ribosomal DNA spacers and on the cox2 mitochondrial gene confirm that these nematodes belong to the taxon Anisakis sp. A, which was previously detected as a larval stage in fishes from Madeiran waters. In addition, our molecular studies demonstrate that Anisakis sp. A and the taxon Anisakis sp., previously found in other Mesoplodon spp., are the same species. The adults of Anisakis sp. A are morphologically similar to A. ziphidarum but with a shorter body length and longer spicules (right spicule 2.42 mm, left spicule 2.30 mm). Since the poor condition of the male tail cuticle prevented a proper description of the caudal plates and the pattern of caudal papillae, we propose to retain the name Anisakis sp. A until new males are described correctly.
Single dose injection snoreplasty: investigation or treatment?
Authors: Al-Jassim A H , Lesser T H J 
Published: June 2008

AbstractIntroduction:Many surgical and nonsurgical procedures have been designed for the treatment of snoring due to palatal flutter. All work in some, but not all, snorers. The difficulty lies in making the definitive diagnosis of palatal flutter as the cause of snoring, and in deciding which patients should undergo which treatment, which in some cases are relatively radical.Aims:This study aimed to assess the usefulness of injection snoreplasty in differentiating palatal flutter from other forms of snoring. This was done in the hope of determining which patients would benefit from definitive palatal surgery such as uvulopalatopharyngoplasty and laser-assisted uvuloplasty.Materials:Sixty consecutive patients referred for habitual snoring were treated with sodium tetradycil sulphate during their first consultation visit. No patients were excluded and none refused the treatment. Forty patients received a single 1 ml dose of 1 per cent sodium tetradycil sulphate, and twenty patients received a single 1 ml dose of 3 per cent sodium tetradycil sulphate under topical anaesthesia. Visual analogue snoring scales were completed by the patient and their partner six weeks, three months, six months and 12 months after the procedure.Results:Forty of the 60 patients showed improvement in snoring and therefore were considered for definitive surgery. Four of the 60 patients found the investigation unpleasant and did not want any further treatment. Of the 40 patients who showed improvement, 29 maintained this at one year. The other 11 underwent uvulopalatopharyngoplasty or laser-assisted palatoplasty. All patients had successful snoring scale outcomes following the surgery.Conclusion:A significant number of the patients, 62 per cent, were demonstrated to have significant improvement in the short term. Single dose injection snoreplasty seems not only to be an effective investigation but may constitute a safe and simple treatment within the clinic. At the very least, patients in whom the palate appears not to be the problem are prevented from undergoing painful, unpleasant surgery. Our results support the use of injection snoreplasty, both as an investigation and in some patients as a treatment, for habitual snoring.
A preliminary floristic classification of southern and northern Victoria Land vegetation, continental Antarctica
Authors: Cannone Nicoletta , Seppelt Rodney 
Published: June 2008

AbstractThis paper proposes a new objectively-generated vegetation classification for southern and northern Victoria Land (continental Antarctica) based on the floristic composition of the plant communities. The new classification aims to integrate the existing physiognomic classification of the cryptogamic Antarctic tundra, provide useful data on floristic composition and distribution of the vegetation occurring in southern and northern Victoria Land, and develop a suitable tool allowing easy comparison of syntaxa from different locations. Field data from 26 sites along a latitudinal gradient (72°–77°S) were analysed by a hierarchical classification integrated with multivariate statistics, including indirect ecological information (Principal Component Analysis). Similarity of the identified groups was assessed through the Jaccard similarity index. The new classification is compatible with previous ones and is widely applicable to Victoria Land and includes previous classification. This standardized approach relates plant communities to their floristic composition and provides a basis for relating vegetation composition to environmental gradients and to patterns of vegetation dynamics and succession which are still poorly understood in Antarctica.
Heparin and structurally related polymers attenuate eotaxin‐1 (CCL11) release from human airway smooth muscle
Authors: Kanabar V , Page C P , Simcock D E , Karner C , Mahn K , O'Connor B J , Hirst S J 
Published: June 2008

Background and purpose:The glycosaminoglycan heparin has anti‐inflammatory activity and is exclusively found in mast cells, which are localized within airway smooth muscle (ASM) bundles of asthmatic airways. Interleukin (IL)‐13 induces the production of multiple inflammatory mediators from ASM including the eosinophil chemoattractant chemokine, eotaxin‐1. Heparin and related glycosaminoglycan polymers having structurally heterogeneous polysaccharide side chains that varied in molecular weight, sulphation and anionic charge were used to identify features of the heparin molecule linked to anti‐inflammatory activity.Experimental approach:Cultured human ASM cells were stimulated with interleukin (IL)‐13 in the absence or presence of heparin and related polymers. Eotaxin‐1 was quantified using chemokine antibody arrays and ELISA.Key results:Unfractionated heparin attenuated IL‐13‐dependent eotaxin‐1 production and this effect was reproduced with low molecular weight heparins (3 and 6 kDa), demonstrating a minimum activity fragment of at least 3 kDa. N‐desulphated, 20% re‐N‐acetylated heparin (anticoagulant) was ineffective against IL‐13‐dependent eotaxin‐1 production compared with 90% re‐N‐acetylated (anticoagulant) or O‐desulphated (non‐anticoagulant) heparin, suggesting a requirement for N‐sulphation independent of anticoagulant activity. Other sulphated molecules with variable anionic charge and molecular weight exceeding 3 kDa (dextran sulphate, fucoidan, chondroitin sulphate B) inhibited IL‐13‐stimulated eotaxin‐1 release to varying degrees. However, non‐sulphated dextran had no effect.Conclusions:Inhibition of IL‐13‐dependent eotaxin‐1 release by heparin involved but did not depend upon sulphation, though loss of N‐sulphation reduced the attenuating activity, which could be restored by N‐acetylation. This anti‐inflammatory effect was also partially dependent on anionic charge, but independent of molecular size above 3 kDa and the anticoagulant action of heparin.British Journal of Pharmacology(2008)154, 833–842; doi:10.1038/bjp.2008.109; published online 21 April 2008
Effect of chondroitin sulphate in a rabbit model of atherosclerosis aggravated by chronic arthritis
Authors: Herrero‐Beaumont G , Marcos M E , Sánchez‐Pernaute O , Granados R , Ortega L , Montell E , Vergés J , Egido J , Largo R 
Published: June 2008

Background and purpose:Among the agents employed to manage osteoarthritis, chondroitin sulphate (CS) is a natural glycosaminoglycan with an anti‐inflammatory effect on joint cells. CS might also influence the inflammatory component of atherosclerosis. Our aim was to examine the effect of CS administration on vascular injury and on markers of systemic inflammation in a rabbit model of atherosclerosis aggravated by systemic inflammation provoked by chronic antigen‐induced arthritis.Experimental approach:Atherosclerosis was induced in rabbits by maintaining them on a hyperlipidaemic diet after producing an endothelial lesion in the femoral arteries. Simultaneously, chronic arthritis was induced in these animals by repeated intraarticular injections of ovalbumin in previously immunized rabbits. A group of these rabbits were treated prophylactically with CS (100 mg kg−1day−1) and when the animals were killed, serum and peripheral blood mononuclear cells (PBMC) were isolated. Furthermore, femoral arteries and thoracic aorta were used for gene expression studies and histological examination.Key results:CS administration reduced the concentration of the proinflammatory molecules C‐reactive protein and IL‐6 in serum. Likewise, CS inhibited the expression of CCL2/monocyte chemoattractant protein (MCP)‐1 and cyclooxygenase (COX)‐2 in PBMC, and reduced the nuclear translocation of nuclear factor‐κB. In the femoral lesion, CS also diminished the expression of CCL2 and COX‐2, as well as the ratio of the intima/media thickness. Moreover, CS decreased the percentage of rabbits with atherosclerosis and chronic arthritis that developed vascular lesions in the aorta.Conclusions and implications:These findings suggest that CS treatment may to some extent impede the progression of atherosclerosis.British Journal of Pharmacology (2008) 154, 843–851; doi:10.1038/bjp.2008.113; published online 21 April 2008
Effects of MiRP1 and DPP6 β‐subunits on the blockade induced by flecainide of KV4.3/KChIP2 channels
Authors: Radicke S , Vaquero M , Caballero R , Gómez R , Núñez L , Tamargo J , Ravens U , Wettwer E , Delpón E 
Published: June 2008

Background and purpose:The human cardiac transient outward potassium current (Ito) is believed to be composed of the pore‐forming KV4.3 α‐subunit, coassembled with modulatory β‐subunits as KChIP2, MiRP1 and DPP6 proteins. β‐Subunits can alter the pharmacological response of Ito; therefore, we analysed the effects of flecainide on KV4.3/KChIP2 channels coassembled with MiRP1 and/or DPP6 β‐subunits.Experimental approach:Currents were recorded in Chinese hamster ovary cells stably expressing KV4.3/KChIP2 channels, and transiently transfected with either MiRP1, DPP6 or both, using the whole‐cell patch‐clamp technique.Key results:In control conditions, KV4.3/KChIP2/MiRP1 channels exhibited the slowest activation and inactivation kinetics and showed an ‘overshoot’ in the time course of recovery from inactivation. The midpoint values (Vh) of the activation and inactivation curves for KV4.3/KChIP2/DPP6 and KV4.3/KChIP2/MiRP1/DPP6 channels were ≈10 mV more negative than Vh values for KV4.3/KChIP2 and KV4.3/KChIP2/MiRP1 channels. Flecainide (0.1–100 μM) produced a similar concentration‐dependent blockade of total integrated current flow (IC50 ≈10 μM) in all the channel complexes. However, the IC50 values for peak current amplitude and inactivated channel block were significantly different. Flecainide shifted the Vh values of both the activation and inactivation curves to more negative potentials and apparently accelerated inactivation kinetics in all channels. Moreover, flecainide slowed recovery from inactivation in all the channel complexes and suppressed the ‘overshoot’ in KV4.3/KChIP2/MiRP1 channels.Conclusions and implications:Flecainide directly binds to the KV4.3 α‐subunit when the channels are in the open and inactivated state and the presence of the β‐subunits modulates the blockade by altering the gating function.British Journal of Pharmacology (2008) 154, 774–786; doi:10.1038/bjp.2008.134; published online 21 April 2008