bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical Synthesis: a Convenient Method for the Preparation of Neutral Metal Complexes with a Thiosemicarbazone Ligand
Authors: Bermejo Manuel R. , González‐Noya Ana M. , Martínez‐Calvo Miguel , Pedrido Rosa , Romero María J. , Fernández M. Isabel , Maneiro Marcelino 
Published: April 2007

AbstractThe interaction of the transition and post‐transition metals manganese, iron, cobalt, nickel, zinc, cadmium and lead, with the ligand 4‐N‐methylthiosemicarbazone‐2‐pyridinecarboxaldehyde (HL) through an electrochemical procedure has been investigated.The novel complexes obtained via this synthetic route have the general formulae [M(L)2](H2O)n (n = 1‐3.5). The crystal and molecular structures have been determined for the mononuclear complexes [MnL2]·H2O (2), [CoL2] (5), [NiL2]·H2O (7) and [PbL2] (11). Complexes 2, 5 and 7 exhibit a distorted octahedral polyhedron around the metal atom, whilst the lead derivative shows a particular coordination polyhedron that may be regarded as a distorted bipyramidal pentagonal structure, with one apical position filled by the metal lone pair.All these complexes have been fully characterized by elemental analysis, infrared spectroscopy, mass spectrometry, magnetic and conductivity measurements, and 1H, 113Cd and 207Pb NMR techniques.
Synthesis and Molecular Structure of trans‐[IrCl(coe)(tBu2PH)2] (coe = cis‐cyclooctene)
Authors: Böttcher Hans‐Christian , Graf Marion , Karaghiosoff Konstantin , Mayer Peter 
Published: April 2007

AbstractThe reaction of [{Ir(μ‐Cl)(coe)2}2] (1) (coe = cis‐cyclooctene) with the secondary phosphane tBu2PH afforded, under defined conditions, the novel complex trans‐[IrCl(coe)(tBu2PH)2] (2), which has been characterized by spectroscopic methods as well as by X‐ray diffraction. Compound 2 represents the first isolated and structurally characterized type of complex trans‐[IrCl(coe)L2] (L = phosphane). The compound is presumably isolable because of the convenient electronic effects of the chosen phosphane ligands.
Syntheses and Structures of Solvated Tetrasodiumtetrachalcogenostannates [Na4(en)4][SnE4] (en = 1,2‐diaminoethane; E = Te, Se), and their Reactions Toward Further Ternary or Quaternary Chalcogenometallates [Mn(en)3]2[Sn2Te6]·4H2O or [Na10(H2O)34][Mn4(μ4‐Se)(SnSe4)4]
Authors: Ruzin Eugen , Zimmermann Christian , Hillebrecht Pierre , Dehnen Stefanie 
Published: April 2007

AbstractA fusion/extraction technique was applied for the syntheses of en solvated (en = 1,2‐diaminoethane) sodium salts of ortho‐chalcogenostannate anions, [Na4(en)4][SnE4] with E = Te (1) or Se (2), possessing homologue composition and similar crystal packing. However, further reactions of 1 and 2 with Mn(OAc)2·4H2O yielded different types of Mn/Sn/E compounds: whereas 1 is converted into an [Mn(en)3]2+ salt of dimeric [Sn2Te6]4− anions (3), the presence of selenium ligands in 2 enables the formation of a ternary anion [Mn4(μ4‐Se)(SnSe4)4]10− in 4, which is the first Na+ salt of this P1‐type anionic cluster. The reactions show both the influence of en ligands on the reaction behavior of ortho‐chalcogenostannate anions and enhance the knowledge of the complex influences onto molecular structures of supertetrahedral cluster anions. Compounds 1–4 were structurally determined by means of single crystal X‐ray diffractometry; lattice dimensions at 203 K: 1 (monoclinic space group P21/c): a: 7.5988(15) Å, b: 26.496(5) Å, c: 13.710(3) Å, β: 92.84(3)°, V: 2756.8(9) Å3; 2 (tetragonal space group P41212): a: 13.0900(19) Å, c: 14.548(3) Å, V: 2492.8(7) Å3; 3 (triclinic space group $P{\bar 1}$): a: 9.3109(19) Å, b: 9.4345(19) Å, c: 12.800(3) Å α: 108.36(3)° β: 98.43(3)° γ: 103.82(3)° V: 1005.8(4) Å3; 4 (triclinic space group P1): a: 14.903(3) Å, b: 15.189(3) Å, c: 15.339(3) Å, α: 90.47(3)°, β: 90.61(3)°, γ: 91.54(3)°, V: 3470.9(12) Å3.
Supranormal dietary folic acid supplementation: effects on methionine metabolism in weanling rats
Authors: Achón M. , Alonso-Aperte E. , Úbeda N. , Varela-Moreiras G. 
Published: April 2007

There are nationwide folic acid (FA) fortification programmes of staple foods established or under consideration in order to prevent neural tube defects. Universal FA fortification still remains controversial because of the concern that additional FA in the diets of population groups (e.g. children and elderly) not initially targeted for fortification may suffer adverse effects. However, dietary surveys regarding folate generally deal with adults and little is known about the consumption and long-term effects of fortified food and supplements in growing individuals. Recent reports from our laboratory show several effects of high-dose folate supplementation in rats. In the present work, we studied the effect of FA on the methionine cycle in weanling (3-week-old) male rats after 4 weeks of supplementation with 40 mg FA/kg dietv.control (1 mg FA/kg diet). FA supplementation resulted in a reduction of homocysteine and creatinine concentrationsv.control group. FA supplementation did not alterS-adenosylmethionine/S-adenosylhomocysteine ratio, DNA methylation, enzymatic activities or concentrations of vitamins involved in the nutritional regulation of the methionine cycle, except for folate. FA supplementation of 40 mg/kg did not lead to hepatic or renal damage. In conclusion, there were no apparent adverse effects on one-carbon metabolism after FA supplementation in the studied conditions.
Nasopharyngeal carcinoma presenting as carotidynia in an 18-year-old patient
Authors: Ellul D , Cutajar J , Borg xuereb H , Said M 
Published: April 2007

AbstractIntroduction:Nasopharyngeal carcinoma can present with a variety of symptoms the most common being painless cervical lymph node metastases, epistaxis and conductive hearing loss.Case report:We report a case of an 18-year-old male patient presenting to the ENT department with left sided carotidynia – severe pain in the neck radiating up to his ear. He had a small, exquisitely tender lump just below the bifurcation of the left common carotid artery. After the appropriate investigations he was diagnosed with nasopharyngeal carcinoma.Discussion:In a literature search on Medline and Pubmed we found no reported cases of nasopharyngeal carcinoma presenting with carotidynia, nor was carotidynia ever found to be associated with nasopharyngeal carcinoma.Conclusion:We believe that this is the first reported case of such a presentation of nasopharyngeal carcinoma.
Role of otoacoustic emission in children with middle-ear effusion and grommets
Authors: Saleem Y , Ramachandran S , Ramamurthy L , Kay N J 
Published: April 2007

Objective: To evaluate the role of otoacoustic emission in children with middle-ear effusion and grommets.Materials and methods: A prospective study was carried out on a total of 90 ears. All children listed for grommet insertion had a pre-operative and post-operative (three to six months after grommet insertion) pure tone audiometry, tympanometry and otoacoustic emission recorded. A comparison was made between pure tone audiometry and otoacoustic emission both pre-operatively and post-operatively.Results: Pre-operatively, 63 ears had an abnormal pure tone audiometry of which 59 had absent otoacoustic emission. Therefore the sensitivity of otoacoustic emission in detecting a conductive loss was 59/63 = 94 per cent (95 per cent confidence interval 85 to 98 per cent). All 27 ears with normal hearing pre-operatively had normal otoacoustic emission. The specificity of otoacoustic emission was 27/27 = 100 per cent, (95 per cent confidence interval, 88 to 100 per cent). The positive predictive value was 59/59 = 100 per cent (95 per cent confidence interval, 94 to 100 per cent). After three to six months all post-operative patients with grommets had a normal pure tone audiometry and otoacoustic emission. So both pure tone audiometry and otoacoustic emission were strongly related both in patients with middle-ear effusion and in patients with grommets.Conclusion: As the demonstration of hearing in young and difficult-to-test children can be problematic and time-consuming, we suggest that otoacoustic emission can be used as an alternative to pure tone audiometry in patients with middle-ear effusion and grommets.
Sudden sensorineural hearing loss in a patient with primary antiphospholipid syndrome
Authors: Kang K-T , Young Y-H 
Published: April 2007

AbstractObjective:Despite multiple systemic manifestations, sudden sensorineural hearing loss in a patient with antiphospholipid syndrome is rarely reported.Patient:A 46-year-old man with primary antiphospholipid syndrome had a sudden onset of hearing loss and tinnitus in the right ear in December 2005, because he discontinued use of warfarin and acetylsalicylic acid for a few days.Results:Audiometry revealed saucer-type sensorineural hearing loss with a pure tone average of 73 dB in the right ear, and flat-type hearing loss with a pure tone average of 25 dB in the left ear. Electronystagmography displayed multiple central signs and bilateral canal paresis, while a vestibular evoked myogenic potential test revealed bilateral delayed responses. After admission, the patient was re-treated with warfarin and acetylsalicylic acid. Follow-up audiometry showed recovery of right-sided hearing, with a pure tone average of 12 dB, three days after presentation.Conclusion:Consensus exists on the effectiveness of anticoagulant agents in aiding a favourable outcome of sudden sensorineural hearing loss in patients with antiphospholipid syndrome.
Construction of a family of Moufang loops
Authors: CURTIS ROBERT T. 
Published: April 2007

AbstractThis paper is an excerpt from a Rayleigh essay submitted at the University of Cambridge in January 1970. We reproduce it now as it gives a general construction of a family of Moufang loops to which all bar one of the finite subloops of the Cayley algebra ${\mathbb O}$ belong. These subloops were classified up to isomorphism in the original essay, but are classified up to equivalence under the action of the group of symmetries of $\mathbb O$ in Boddington and Rumynin [1]. Explicitly, given a group G with an element a such that a2=1 in its centre, we construct a Moufang group $\hat G$ in which G has index 2. $\hat G$ will be non-associative unless G is abelian.
The growth of univalent functions with an initial gap II
Authors: AHARONOV DOV , HAYMAN WALTER K. 
Published: April 2007

AbstractWe consider the class Sp of functions

univalent in the unit disk Δ.In [1] it was shown that if f∈Sp and p is large,
(0.1)
Here we show that there exists f in Sp for p=1,2,. . . such that

where C0 is a positive absolute constant.
A star-graph model via operator extension
Authors: PAVLOV B. 
Published: April 2007

AbstractOne usually assumes that the Schrödinger operator on a thin quantum network (“fattened graph”) can be simulated by the ordinary Schrödinger operator on the corresponding one-dimensional quantum graph. On the other hand, each quantum graph can be constructed of standard elements – star graphs. We prove that a thin star-shaped quantum network which consists of a compact domain and a few straight semi-infinite quantum wires, with a two-dimensional Schrödinger operator on it, can be simulated by the corresponding solvable model in form of a one-dimensional star graph: an outer space, with an ordinary Schrödinger operator on the leads, a resonance vertex supplied with an inner space and a finite matrix in it and an appropriate boundary condition connecting the inner and outer components of elements from the domain of the model. The model is (locally) quantitatively consistent: the scattering matrix of the model on a certain spectral interval serves an approximation of the scattering matrix of the network. The role of the constructed star-graph model as a “jump-start” in analytic perturbation procedure on continuous spectrum is discussed.
Schwarz–Christoffel mappings to unbounded multiply connected polygonal regions
Authors: CROWDY DARREN 
Published: April 2007

AbstractA formula for the generalized Schwarz–Christoffel conformal mapping from a bounded multiply connected circular domain to an unbounded multiply connected polygonal domain is derived. The formula for the derivative of the mapping function is shown to contain a product of powers of Schottky–Klein prime functions associated with the circular preimage domain. Two analytical checks of the new formula are given. First, it is compared with a known formula in the doubly connected case. Second, a new slit mapping formula from a circular domain to the triply connected region exterior to three slits on the real axis is derived using separate arguments. The derivative of this independently-derived slit mapping formula is shown to correspond to a degenerate case of the new Schwarz–Christoffel mapping. The example of the mapping to the triply connected region exterior to three rectangles centred on the real axis is considered in detail.
Algebraicity of L-values for elliptic curves in a false Tate curve tower
Authors: BOUGANIS THANASIS , DOKCHITSER VLADIMIR 
Published: April 2007

AbstractLet E be an elliptic curve over ${\mathbb Q}$, and τ an Artin representation over ${\mathbb Q}$ that factors through the non-abelian extension ${\mathbb Q}(\sqrt[p^n]{m},\mu_{p^n})/{\mathbb Q}$, where p is an odd prime and n, m are positive integers. We show that L(E,τ,1), the special value at s=1 of the L-function of the twist of E by τ, divided by the classical transcendental period Ω+d+|Ω−d−|ε(τ) is algebraic and Galois-equivariant, as predicted by Deligne's conjecture.
Strongly-cyclic branched coverings and the Alexander polynomial of knots in rational homology spheres
Authors: KODA YUYA 
Published: April 2007

AbstractLet K be a knot in a rational homology sphere M. In this paper we correlate the Alexander polynomial of K with a g-word cyclic presentation for the fundamental group of the strongly-cyclic covering of M branched over K. We also give a formula for the order of the first homology group of the strongly-cyclic branched covering.
Pharmacokinetic‐pharmacodynamic modelling ofS(−)‐atenolol in rats: reduction of isoprenaline‐induced tachycardia as a continuous pharmacodynamic endpoint
Authors: van Steeg T J , Freijer J , Danhof M , de Lange E C M 
Published: April 2007

Background and purpose:For development of mechanism‐based pharmacokinetic‐pharmacodynamic (PK‐PD) models, continuous recording of drug effects is essential. We therefore explored the use of isoprenaline in the continuous measurement of the cardiovascular effects of antagonists of β‐adrenoceptors (β‐blockers). The aim was to validate heart rate as a pharmacodynamic endpoint under continuous isoprenaline‐induced tachycardia by means of PK‐PD modelling ofS(−)‐atenolol.Experimental approach:Groups of WKY rats received a 15 min iv infusion of 5 mg kg−1S(−)‐atenolol, with or without iv infusion of 5 μg kg−1h−1isoprenaline. Heart rate was continuously monitored and blood samples were taken.Key results:A three‐compartment model best described the pharmacokinetics ofS(−)‐atenolol. The PK–PD relationship was described by a sigmoid Emax model and an effect compartment was used to resolve the observed hysteresis. In the group without isoprenaline, the variability in heart rate (30 b.p.m.) approximated the maximal effect (Emax=43±18 b.p.m.), leaving the parameter estimate of potency (EC50=28±27 ng ml−1) unreliable. Both precise and reliable parameter estimates were obtained during isoprenaline‐induced tachycardia: 517±13 b.p.m. (E0), 168±15 b.p.m. (Emax), 49±14 ng ml−1(EC50), 0.042±0.012 min−1(keo) and 0.95±0.34 (n).Conclusions and implications:Reduction of heart rate during isoprenaline‐induced tachycardia is a reliable pharmacodynamic endpoint for β‐blockersin vivoin rats. Consequently this experimental approach will be used to investigate the relationship between drug characteristics andin vivoeffects of different β‐blockers.British Journal of Pharmacology(2007)151, 356–366; doi:10.1038/sj.bjp.0707234
Thromboxane A2inhibition of SKCaafter NO synthase block in rat middle cerebral artery
Authors: McNeish A J , Garland C J 
Published: April 2007

Background and purpose:NO/prostanoid independent, EDHF‐mediated hyperpolarization and dilation in rat middle cerebral arteries is mediated solely by endothelial cell IKCa. However, when the NO‐pathway is also active, both SKCaand IKCacontribute to EDHF responses. As the SKCacomponent can be inhibited by stimulation of thromboxane A2(TxA2) TP receptors and NO has the potential ability to inhibit thromboxane synthesis, we investigated whether TxA2might explain loss of functional input from SKCaduring NOS inhibition in cerebral arteries.Experimental approach:Rat middle cerebral arteries were mounted in a wire myograph. Endothelium‐dependent responses to the PAR2 agonist, SLIGRL were assessed as simultaneous changes in smooth muscle membrane potential and tension.Key results:Responses were obtained in the presence ofL‐NAME as appropriate. Inhibition of TP receptors with either ICI 192,605 or SQ 29,548, did not affect EDHF mediated hyperpolarization and relaxation, but in their presence neither TRAM‐34 nor apamin (to block IKCaand SKCarespectively) individually affected the EDHF response. However, in combination they virtually abolished it. Similar effects were obtained in the presence of the thromboxane synthase inhibitor, furegrelate, which additionally revealed an iberiotoxin‐sensitive residual EDHF hyperpolarization and relaxation in the combined presence of TRAM‐34 and apamin.Conclusions and implications:In the rat middle cerebral artery, inhibition of NOS leads to a loss of the SKCacomponent of EDHF responses. Either antagonism of TP receptors or block of thromboxane synthase restores an input through SKCa. These data indicate that NO normally enables SKCaactivity in rat middle cerebral arteries.British Journal of Pharmacology(2007)151, 441–449; doi:10.1038/sj.bjp.0707240
GW3965, a synthetic liver X receptor (LXR) agonist, reduces angiotensin II‐mediated pressor responses in Sprague–Dawley rats
Authors: Leik C E , Carson N L , Hennan J K , Basso M D , Liu Q‐Y , Crandall D L , Nambi P 
Published: April 2007

Background and purpose:Liver X receptors (LXRs) activate genes that regulate lipid and cholesterol metabolism. LXR agonists were shown recently to also increase murine renin gene expression in vivo. To further examine a link between lipid metabolism, the renin‐angiotensin‐aldosterone‐system and blood pressure regulation, we investigated the effect of a LXR agonist (GW3965) on angiotensin II (Ang II)‐mediated vasoreactivity and vascular angiotensin II receptor (ATR) gene expression.Experimental approach:Arterial blood pressure (BP) was measured during Ang II infusions (1.5 min duration; 0.001–3 μg kg−1) in pentobarbital‐anesthetized male Sprague–Dawley rats (n = 6‐9) after oral administration of GW3965 (10 mg kg−1, q.d.) or vehicle for 7 – 15 days. Mesenteric arteries and plasma were collected to analyze ATR gene expression and to measure plasma renin activity (PRA) and lipid profile, respectively.Key results:Basal mean arterial pressure (MAP) was similar between groups. GW3965 dosing blunted the vasopressor effect of Ang II, which was significantly different with the 0.3 and 3 μg kg−1 doses. No difference in heart rate, PRA or lipid profile was observed between groups. A time‐course indicated that ATR type 1 and 2 gene expression of GW3965‐treated vs. vehicle‐treated rats decreased by 50%, reaching significance for ATR type 2, but not for ATR type 1, at time‐points coinciding with BP measurements.Conclusions and implications:GW3965 decreased Ang II‐mediated vasopressor responses coincident with a trend toward reduced ATR gene expression, suggesting that LXR agonists could affect vascular reactivity.British Journal of Pharmacology (2007) 151, 450–456; doi:10.1038/sj.bjp.0707241
Flavonoids inhibit the platelet TxA2signalling pathway and antagonize TxA2receptors (TP) in platelets and smooth muscle cells
Authors: Guerrero José A. , Navarro‐Nuñez Leyre , Lozano María L. , Martínez Constantino , Vicente Vicente , Gibbins Jonathan M. , Rivera José 
Published: April 2007

What is already known about this subject• Flavonoids are largely recognized as potential inhibitors of platelet function, through nonspecific mechanisms such as antioxidant activity and/or inhibition of several enzymes and signalling proteins.• In addition, we, and few others, have shown that certain antiaggregant flavonoids may behave as specific TXA2 receptor (TP) ligands in platelets.• Whether flavonoids interact with TP isoforms in other cell types is not known, and direct evidence that flavonoid–TP interaction inhibits signalling downstream TP has not been shown.What this study adds• This study first demonstrates that certain flavonoids behave as ligands for both TP isoforms, not only in platelets, but also in human myometrium and in TP‐transfected HEK 293T cells.• Differences in the effect of certain flavonoids in platelet signalling, induced by either U46619 or thrombin, suggest that abrogation of downstream TP signalling is related to their specific blockage of the TP, rather than to a nonspecific effect on tyrosine kinases or other signalling proteins.AimsFlavonoids may affect platelet function by several mechanisms, including antagonism of TxA2receptors (TP). These TP are present in many tissues and modulate different signalling cascades. We explored whether flavonoids affect platelet TP signalling, and if they bind to TP expressed in other cell types.MethodsPlatelets were treated with flavonoids, or other selected inhibitors, and then stimulated with U46619. Similar assays were performed in aspirinized platelets activated with thrombin. Effects on calcium release were analysed by fluorometry and changes in whole protein tyrosine phosphorylation and activation of ERK 1/2 by Western blot analysis. The binding of flavonoids to TP in platelets, human myometrium and TPα‐ and TPβ‐transfected HEK 293T cells was explored using binding assays and the TP antagonist3H‐SQ29548.ResultsApigenin, genistein, luteolin and quercetin impaired U46619‐induced calcium mobilization in a concentration‐dependent manner (IC5010–30 µm). These flavonoids caused a significant impairment of U46619‐induced platelet tyrosine phosphorylation and of ERK 1/2 activation. By contrast, in aspirin‐treated platelets all these flavonoids, except quercetin, displayed minor effects on thrombin‐induced calcium mobilization, ERK 1/2 and total tyrosine phosphorylation. Finally, apigenin, genistein and luteolin inhibited by >50%3H‐SQ29548 binding to different cell types.ConclusionsThese data further suggest that flavonoids may inhibit platelet function by binding to TP and by subsequent abrogation of downstream signalling. Binding of these compounds to TP occurs in human myometrium and in TP‐transfected HEK 293T cells and suggests that antagonism of TP might mediate the effects of flavonoids in different tissues.
Effect of timing of dosing in relation to food intake on the pharmacokinetics of esomeprazole
Authors: Sostek Mark B. , Chen Yusong , Andersson Tommy 
Published: April 2007

What is already known about this subject Systemic esomeprazole exposure is decreased when administered simultaneously with food. What this study adds Taking esomeprazole within 15 min of eating a high‐fat, high‐calorie meal results in reduced systemic drug exposure.AimTo investigate the pharmacokinetics of esomeprazole before a high‐fat meal vs. fasting.MethodsThis open‐label, randomized, crossover study consisted of two 5‐day dosing periods of esomeprazole 40 mg per day. On days 1 and 5, subjects received esomeprazole 15 min before a high‐fat meal (fed) or 4 h before a non‐high‐fat meal (fasting).ResultsOn days 1 and 5, ratio of fed to fasting area under the plasma concentration–time curve [0.56, 90% confidence interval (CI) 0.50, 0.64, and 0.78, 90% CI 0.74, 0.82, respectively] and peak plasma concentration (0.34, 90% CI 0.28, 0.41, and 0.47, 90% CI 0.41, 0.52, respectively) were outside of the limits of bioequivalence.ConclusionsEsomeprazole bioavailability was reduced when taken within 15 min before eating a high‐fat meal vs. that while fasting.