bluuebunny/crossref_metadata_2025 huggingface dataset:
Deactivation of Cd(53PJ) by H2 and D2: Branching Ratios for the Production of CdH and CdD
Authors: Umemoto Hironobu , Ohsako Nobuhiro
Published: June 2006

The deactivation processes of Cd(53P1) and Cd(53P0) by H2 and D2 were examined by employing a laser excitation-depletion technique. The concentration of the ground-state Cd(51S0) atoms was measured in both the presence and absence of an intense saturable pump laser beam. In the presence of a pump laser, the concentration decreased in accordance with the production of CdH(CdD). From this decrease, the branching ratios for the production of CdH(CdD) could be determined. The depletion was unaffected when N2 was added. This suggests that the branching ratios are the same for Cd(53P1) and Cd(53P0), although the production of CdH(CdD) is endothermic for Cd(53P0). The branching ratios were 0.81 ± 0.04 for H2 and 0.76 ± 0.06 for D2. The efficient production of CdH(CdD) from not only Cd(53P1), but also Cd(53P0), can be accounted for by correlational considerations.
Simple Synthesis of trans-α,β-Dibenzyl-γ-butyrolactone Lignans by Diastereoselective Reduction of α-Benzylidene-β-benzyl-γ-butyrolactones Using NaBH4–NiCl2
Authors: Moritani Yasunori , Fukushima Chiaki , Miyagishima Toshikazu , Ohmizu Hiroshi , Iwasaki Tameo
Published: June 2006

trans-α,β-Dibenzyl-γ-butyrolactone lignans were synthesized by stereoselective reduction of α-benzylidene-β-benzyl-γ-butyrolactones using NaBH4–NiCl2. The reduction is found to proceed via conjugate addition of a hydride to an α-benzylidene-β-benzyl-γ-butyrolactone and the stereoselective protonation of the resulting metal enolate. The stereoselectivity would be brought about by the conformational rigidity of the phenyl moiety of the α-benzyl group induced by 1,3-allylic strain.
N,N′-Difluoro-1,4-diazoniabicyclo[2.2.2]octane Salts, Highly Reactive and Easy-to-Handle Electrophilic Fluorinating Agents
Authors: Umemoto Teruo , Nagayoshi Masayuki
Published: June 2006

A series of N,N′-difluoro-1,4-diazoniabicyclo[2.2.2]octane salts were synthesized in a pure form by the fluorination of 1,4-diazabicyclo[2.2.2]octane with F2 diluted with N2 in the presence of a Brønsted acid in fluoro alcohol or acetonitrile or by fluorination followed by a treatment with a different Brønsted or Lewis acid. Their complete structural assignment was made based on spectral and elemental analyses of the isolated crystals. A great through-bond interaction between the two N–F’s of the salt was observed on 19F NMR. An assessment was made of the usefulness of N,N′-difluoro-1,4-diazoniabicyclo[2.2.2]octane bis(triflate), bis(HSO4), bis(BF4), and bis(SbF6) salts for electrophilic fluorination; the bis(BF4) salt was demonstrated to be widely applicable as a highly reactive and easy-to-handle fluorinating agent. Thus, the bis(BF4) salt readily fluorinated activated aromatics, active methylene compounds or their salts, substituted styrenes, and vinyl acetates under mild conditions. It was shown that one N–F of the salt was effective for fluorination and that the other N–F played a role to activate fluorination through the bonds. Thus, the reaction mechanism was discussed, and fluorination followed by an immediate intramolecular one-electron transfer was suggested.
Palladium(II)-Catalyzed Conjugate Addition of Aromatics to α,β-Unsaturated Ketones and Aldehydes with Arylantimony Compounds
Authors: Cho Chan Sik , Motofusa Shin-ichi , Ohe Kouichi , Uemura Sakae
Published: June 2006

Triarylstibines react with α,β-unsaturated ketones and aldehydes in acetic acid at room temperature in the presence of AgOAc and a catalytic amount of Pd(OAc)2 to afford the conjugate addition products (the formal hydroarylated compounds to an olefinic part) in good yields. In contrast, diarylantimony chlorides, arylantimony dichlorides, and diphenylantimony acetate react with the enones and enals even in the absence of AgOAc to afford the same products in higher yields compared with those from triarylstibines. These are new C–C bond-forming reactions using arylantimony(III) compounds in which the formation of a palladium enolate or a trivalent antimony enolate is proposed as an intermediate.
Crystalline-State Reaction of Cobaloxime Complexes. 19. A New Mode of Racemization of the 1-Cyanoethyl Group
Authors: Ohgo Yoshiki , Ohashi Yuji
Published: June 2006

The crystal of [(R)-1-cyanoethyl][bis(dimethylglyoximato)](3-hydroxypyridine)cobalt(III) benzene solvate showed racemization along with a retention of the single-crystal form upon exposure to a fluorescent lamp. The crystal data before irradiation are as follows: [Co(C3H4N)(C4H7N2O2)2(C5H5NO)] ·2C6H6, F.W. = 594.6, triclinic, P1, Z = 2, a = 11.646(3), b = 13.267(4), c = 11.303(3) Å, α = 102.57(2), β = 101.27(2), γ = 113.38(2)°, V = 1485.2(9) Å3, Dx = 1.33 Mg m−3, μ(Mo Kα) = 0.624 mm−1, F(000) = 624, and T = 296 K. The structure was solved by the direct method and refined to R = 0.067, wR2 = 0.180. Upon exposure to a fluorescent lamp, the cell dimensions were gradually changed, and became significantly small after 150 h of irradiation. The cell dimensions became as follows: a = 11.596(4), b = 13.287(3), c = 11.297(2) Å, α = 102.51(2), β = 101.26(2), γ = 113.37(2)°, and V = 1481.1(8) Å3. The analysed structure showed that a crystallographic inversion center appeared between the two molecules, and that the space group changed from P1 to . The 1-cyanoethyl groups of the two molecules were transformed to disordered racemates. In the process of racemization, the cyano and methyl groups were exchanged, although the methyl group has been exchanged with hydrogen in the related crystals so far observed. The racemic crystal obtained from a solution showed approximately the same structure as that by photoirradiation. The reason why such a new mode of racemization occurred was clearly explained by the size and shape of the reaction cavities for the two 1-cyanoethyl groups in the structure before irradiation.
Rotational Isomers and Molecular Structures of (E)-Propionaldehyde Oxime as Studied from Electron Diffraction and Microwave Spectroscopic Data
Authors: Iijima Kinya , Matsuoka Mayumi , Sakaizumi Takeshi , Ohashi Osamu
Published: June 2006

The molecular structures of two rotational isomers (anticlinal and synperiplanar forms) of gaseous (E)-propionaldehyde oxime have been determined from electron diffraction and microwave spectroscopic data. The anticlinal form is more stable by 0.15 ± 0.10 kcal mol−1 than the synperiplanar form. The molecular parameters of the anticlinal form are rg(C1–C2) = 1.552(3) Å, rg(C2–C3) = 1.493(2) Å, rg(C3=N) = 1.284(2) Å, rg(N–O) = 1.429(2) Å, ∠C1C2C3 = 111.5(1)°, ∠C2C3N = 119.0(3)°, and ∠C3NO = 109.4(2)°. The ∠C2C3N, ∠C1C2C3, and rg(C3–N) values of the synperiplanar form (122.6(6)°, 112.6(6)°, and 1.291(3) Å, respectively) are not equal to those of the anticlinal form.
Separation of the Diffusion Potential within a Membrane and the Donnan Potential on the Basis of a Measurement of Transient Membrane Potentials
Authors: Nomura Kazuo
Published: June 2006

In the perfluoro carboxylate cation exchange membrane–aqueous electrolyte systems, two steps appeared in the time course of the membrane potential in response to a pH jump in the external solution. LiCl, NaCl, and KCl were used as the electrolytes. According to the experimentally observed curve of the potential transient, the membrane potential was divided in two portions: the potential difference at the membrane/solution interface (Donnan potential) and the intramembrane diffusion potential. It was found that the differences among the total membrane potentials for three kinds of alkali metal ion systems were mainly attributed to the generation process of the diffusion potential within the membrane. The pH dependencies of the Donnan potential and intramembrane diffusion potential were calculated on the basis of a theory starting at the Nernst–Planck equation for the ion diffusion. Calculations were carried out taking into account the association/dissociation reaction of hydrogen ions and ion exchange groups and the heterogeneous structure of the membrane. By fitting the theoretical equations to the experimental results, the best-fitting values of relative mobility of ion and the dissociation constant of COOH group in the membrane were obtained.
Simple and Rapid Determination of the Activation Parameters of Organic Reactions by Temperature-Dependent NMR Spectroscopy II. Application to Reversible Reactions
Authors: Satoh Masahiro , Hirota Minoru
Published: June 2006

A non-isothermal (NIT) method for evaluating the activation enthalpies and entropies of reactions in solutions was applied to several reversible reactions. This was realized by a stepwise elevation of the temperature of a reaction system using a variable-temperature apparatus comprising on NMR spectrometer and a quick collection of FID (free induction decay) at every plateau of the step. The rate from NIT experiments agreed well with the previously measured rates by the conventional methods.
Reaction of Alkynyl(phenyl)(p-phenylene)bisiodonium Ditriflates with Nucleophiles. High Reactivity of the Alkynyl Component
Authors: Kitamura Tsugio , Fukuoka Takahiro , Zheng Lei , Fujimoto Takeshi , Taniguchi Hiroshi , Fujiwara Yuzo
Published: June 2006

Reaction of alkynyl(p-phenylene)bisiodonium ditriflates with potassium thiocyanate in DMF gave alkynyl thiocyanates and p-iodophenyl(phenyl)iodonium triflate. The latter was readily removed by washing with water. The exclusive sulfur attack of thiocyanate ion suggests that the alkynyl group behaves as a soft acceptor of nucleophiles. The reactions with the enolate anion of 2-phenyl-1,3-indandione in DMF afforded 2-(1-cyclopentenyl)-2-phenyl-1,3-indandiones in the cases of 1-hexynyl- and 1-octynyl-(p-phenylene)bisiodonium ditriflates. In the reactions of 3,3-dimethyl-1-butynyl-, phenylethynyl-, and trimethylsilylethynyl-(p-phenylene)bisiodonium ditriflates, 2-alkynyl-2-phenyl-1,3-indandiones were obtained. The same reactions with the enolate anion of 2-phenyl-1,3-indandione in a mixed solvent of 2-methyl-2-propanol and THF improved the yields of the 1-cyclopentenyl- and alkynyl-substituted indandiones. A large difference in the reaction pathways between the (p-phenylene)bisiodonio and phenyliodonio moieties was observed in the sterically hindered 3,3-dimethyl-1-butynyl systems.
Bindings of a Secondary Polymer to Monodisperse Colloidal Silica Particles Modified with Poly(maleic anhydride–styrene) for Controlling the Surface Polarity
Authors: Yoshinaga Kohji , Teramoto Makoto
Published: June 2006

A polymer modification of monodisperse colloidal silica (120 nm in diameter) and control of the surface polarity were studied. The binding of poly(maleic anhydride–styrene) to the silica particles and successive grafting of amino-terminated polymethacrylates with methyl, hexyl, and dodecyl ester groups afforded unimodal composite particles, which were dispersible in a low-polar solvent of ethyl acetate. The bindings of the secondary polymer were dependent on the molecular structure of the polymer as well as the reaction conditions. The surface polarity was estimated by aggregation of the particles in an ethyl acetate–methanol cosolvent, monitored by the absorbance of a suspension containing the composite particles at 500 nm. The polarity was significantly affected by the main chain length of the secondary polymer of the polymethacrylates rather than the bound polymer chain number or the branch alkyl ester group of the polymer. For highly modified composite particles, it was observed that the carboxyl group, simultaneously formed in the binding of the secondary polymer, contributed to the surface polarity.
Ab Initio Molecular Orbital Studies of Singlet Oxygen Reactions of Olefins, Enol Ethers, and Enamines
Authors: Yoshioka Yasunori , Yamada Satoru , Kawakami Takashi , Nishino Masamichi , Yamaguchi Kizashi , Saito Isao
Published: June 2006

Ab initio molecular orbital (MO) studies of singlet oxygen reactions of olefins, enol ethers, and enamines were carried out. The relative stabilities of biradical (BR), the so-called perepoxide-like (PE), perepoxide-like zwitterionic (PEZW) and zwitterionic (ZW) intermediates for singlet oxygen reactions of these species are described theoretically, together with their ionization potentials, molecular structures and solvation energies. The activation energies for the ene and dioxetane formation reactions were found to be determined by the electron-donating properties of substituents introduced to these substrates. The following conclusions were drawn from these calculated results: (1) A nonradical transition state with a PE-like conformation is the most plausible for ene reactions of allylic olefins and enol ether with allylic hydrogens. (2) A BR mechanism is favorable for the (2 + 2) reactions of singlet oxygen with simple olefins in the gas phase. (3) A nonconcerted mechanism via polar (PEZW, ZW) intermediates is operative for (2 + 2) cycloadditions of unsymmetrical enol ethers in the solution phase, whereas the (2a + 2a) mechanism and a two-step mechanism via the PE intermediate are conceivable for the (2 + 2) reactions of symmetrical olefins in the solution phase. The implications of these theoretical results to the mechanisms of singlet oxygen reactions are discussed in relation to various experimental results, such as the stereochemistry, isotope effects, solvent effects and laser-photolysis experiments.
Theoretical and Experimental Studies of a Charge-Transfer Mechanism for Biomimetic Oxygenations of Phenol and Indol Derivatives
Authors: Yoshioka Yasunori , Yamanaka Syusuke , Yamada Satoru , Kawakami Takashi , Nishino Masamichi , Yamaguchi Kizashi , Nishinaga Akira
Published: June 2006

The structures and stabilities of organodioxide anions, charge-transfer (CT) complexes between carbanions and molecular oxygen, and related solvated clusters were investigated using ab initio and semiempirical MO plus intermolecular CT theories. The computational results, together with experimental evidence, have revealed the characteristics of potential curves, indicating that the nonradical mechanism via CT complexes is operative for base-catalyzed dioxygenation reactions of phenol and indole derivatives. The following conclusions were drawn from the present calculations: (1) The reactions of carbanion with triplet molecular oxygen proceed through a one-electron transfer (ET) mechanism from carbanion to 3O2. (2) The base-promoted phenol monoanion reacts with molecular oxygen via two different mechanism: one is the CT mechanism, where the triplet CT complex is formed and a spin inversion from a triplet CT complex to a singlet CT one occurs in aprotic solvents; the other involves the one ET mechanism assisted by hydrogen bonding in a protic solvent. (3) The one ET does not occur for the free monoanions of the indole derivatives; rather these species are readily oxygenated by organo-cobalt catalysts. (4) For the flavin derivatives, the CT mechanism is applicable in an aprotic solution, while both the CT and one ET mechanisms are conceivable in aqueous solution. The implications of these results to biological dioxygenations by metallo-dioxygenases are discussed in relation to biomimetic oxygenations of phenol and indole derivatives.
Crystal and Molecular Structures of Novel Metal–Carbene Complexes I. {1,1′-(Perhydropyrimidine-1,3-diyl-κC2)bis[(alkyl/arylimino)methanethiolato-κ2SS′]}(triphenylphosphine)–Pt/Pd Complexes
Authors: Yasui Masanori , Yoshida Satoshi , Kakuma Seiji , Shimamoto Souichi , Matsumura Noboru , Iwasaki Fujiko
Published: June 2006

2,3,4,5-Tetrahydro-1,6-dialkyl-3,4-trimethylene-6aλ4-thia-1,3,4,6-tetraazapentalene-2,5-dithiones (1), which contain a hypervalent sulfur atom, have been found to give novel complexes by treating with Pt(PPh3)4 and Pd(PPh3)4. X-Ray investigations have revealed that the resultant complexes are novel metal–carbene complexes: {1,1′-(perhydropyrimidine-1,3-diyl-κC2)bis[(methylimino)methanethiolato-κ2SS′]}(triphenylphosphine)platinum(II) (2a), {1,1′-(perhydropyrimidine-1,3-diyl-κC2)bis[(ethylimino)methanethiolato-κ2SS′]}(triphenylphosphine)platinum(II) (2b), {1,1′-(perhydropyrimidine-1,3-diyl-κC2)bis[(methylimino)methanethiolato-κ2SS′ ]}(triphenylphosphine)palladium(II) (3a), {1,1′-(perhydropyrimidine-1,3-diyl-κC2)bis[(4-chlorophenylimino)methanethiolato-κ2SS′]}(triphenylphosphine)palladium(II) (3c). The central sulfur atom in 1 was substituted by a metal atom and thioamide groups rotated to form metal–sulfur bonds in the resultant metallapentalene framework. The Pt and Pd atoms are four-coordinated by two S atoms, a C atom and a P atom in a square-planar configuration. The metallapentalene framework in each complex is planar. The R values are 0.042, 0.029, 0.046, and 0.054 for 4114, 5849, 5005, and 7106 observed reflections for 2a, 2b, 3a, and 3c, respectively.
Crystal and Molecular Structures of Novel Metal–Carbene Complexes III. Rh–Carbene Complexes and Cu Complex
Authors: Iwasaki Fujiko , Yasui Masanori , Yoshida Satoshi , Nishiyama Hideyuki , Shimamoto Souichi , Matsumura Noboru
Published: June 2006

2,3,4,5-Tetrahydro-1,6-dialkyl-3,4-trimethylene-6aλ4-thia-1,3,4,6-tetraazapentalene-2,5-dithiones (1), which contain a hypervalent sulfur atom, have been found to give novel metal–carbene complexes by treating with RhCl(PPh3)3. X-Ray investigations have revealed that the resultant complexes are novel Rh–carbene complexes: trans(P,P′)-(chloro){[3-(methylthiocarbamoyl-κN)perhydropyrimidine-1-yl-κC2](methyliminomethanethiolato-κS)}-bis(triphenylphosphine)rhodium(III) (4a) and trans(P,P′)-(chloro){(perhydropyrimidine-1,3-diyl-κC2)bis[(4-chlorophenylimino)methanethiolato-κ2SS′]}bis(triphenylphosphine)rhodium(III) (4c). In these complexes, the central sulfur atom in 1 was substituted by a Rh atom. In 4a, obtained from 1,6-dimethyl-pentalene (1a), only one of the sulfur atoms of the thioamide groups coordinates the Rh atom, while the other thioamide group coordinates Rh with the N atom. Rh is coordinated by S, N, C, and Cl atoms to form an equatorial plane, and is coordinated by two PPh3 groups axially. In 4c, obtained from the 4-chlorophenyl derivative (1c), two thioamide groups rotated to form an S–Rh–S bond. A reaction of 1a with Cu(ClO4)2 gave a different kind of complex, bis (2,3,4,5-tetrahydro-1,6-dimethyl-3,4-trimethylene-6aλ4-thia-1,3,4,6-tetraazapentalene-2,5-dithione-κ2S4)copper(I) (7). The framework of the starting tetraazathiapentalene 1 remained unsubstituted, and the sulfur atoms of the thiocarbonyl groups of 1 coordinated the Cu atom to form one-dimensional coordination polymers, where the Cu atom is coordinated tetrahedrally by four S atoms. Because of a difference in the changes of the oxidation numbers of the metals during the reactions, metal–carbene complexes could not be obtained in the case of the Cu-complex.
Hydration of N,N-Bis(2-ethylhexyl)hexanamide in Dodecane
Authors: Naganawa Hirochika , Ohta Yasuo , Tachimori Shoichi
Published: June 2006

The hydration and dimerization of N,N-bis(2-ethylhexyl) hexanamide (BEHHA) in dodecane were studied on the basis of the water distribution between aqueous solutions and dodecane. The data obtained at 298 K were analyzed as functions of the amide concentration in the organic phase and the water activity in the aqueous phase. When the amide was monomeric in the organic phase, only a monohydrate was formed. At high amide concentrations in the organic phase, dimerization of the monohydrate occurred and (BEHHA)2(H2O)2 was formed. No other dimer hydrates were found in the organic phase. The results were compared with those of tributyl phosphate (TBP). The stoichiometry between BEHHA and water was investigated from low to very high amide concentrations in dodecane. The change in the activity coefficient for an amide contained in an inert solvent at high concentrations was also examined.
Studies of {[1](1,1′)Ferroceno[1](1,1′)ruthenocenophane}-1-ylium Hexafluorophosphate and Related α-Carbonium Salts
Authors: Watanabe Masanobu , Motoyama Izumi , Takayama Toshio
Published: June 2006

The oxidation of [1](1,1′)ferroceno[1](1,1′)ruthenocenophane ([1.1]FcRc) and ferrocenylruthenocenylmethane (FcCH2Rc) with bromo- or chlorobis(η5-cyclopentadienyl)ruthenocenium(1+) hexafluorophosphates gave the title compound, [Fe(C5H4CH2C5H4)(C5H4CH+C5H4)Ru]PF6− (1), as an α-carbonium salt and ferrocenylruthenocenylmethylium+ hexafluorophosphate [FeCp(C5H4CH+C5H4)CpRu]PF6− (3), respectively. The crystal of 1 has been found to be triclinic, space group , a = 10.572(9), b = 10.581(3), c = 9.680(5) Å, α = 99.50(3)°, β = 108.14(5)°, γ = 88.30(5)°, Z = 2, and the final R = 0.082 and Rw = 0.094. The distance between the Ru and Fe is 4.507(3) Å; which is much shorter than the value of neutral [1.1]FcRc one (4.792(2) Å). The two C5H4-rings in the Rc moiety are tilted largely (the tilting angle is 10.74°) due to a strong Ru···Cα (α-metylium) interaction. The crystal of 3 has been found to be orthorhombic, space group Pbca, a = 17.062(5), b = 19.172(6), c = 12.580(7) Å, Z = 8, and the final R = 0.067 and Rw = 0.072. The tilting angle of the Rc moiety is 7.98°. The most interesting difference between 1 and 3 is found in the distance between the Ru and Cα atoms; i.e., the distance of 3 (2.43(2) Å, closer to the Ru–C covalent bond) is significantly shorter than the value of 1 (2.51(1) Å, somewhat longer to the covalent bond); therefore, the greater positive –CH+– charge can be stabilized by a delocalization of the charge over the [RuCp(C5H4CH)]+ fragment for 3. However, the –CH+– charge is spread out over [Fe(C5H4CHC5H4)(C5H4CH2C5H4)Ru]+ for 1. Temperature-dependent 57Fe-Mössbauer spectroscopy (areal intensity ratio of ferrocene and ferrocenium) supports above the conclusion.
Low-Water-Content Diazomethane-d2 and Its Isotopic Assay
Authors: Strazzolini Paolo , Giumanini Angelo G , Verardo Giancarlo
Published: June 2006

A multiple D2O–CH2N2 exchange followed by a final anhydrification with K2CO3 gave an alcohol-free low-water-content ether solution of CD2N2. Procedural improvements for the exchange are reported. The extent of deuteration with a quantitative evaluation of the actual species present in any solution of diazomethane could be determined by a GC-MS analysis and 1H NMR spectrometry on a suitable derivative. In addition, a procedure for the quantitative determination of water in diazomethane solutions has been developed.
Comparison of biomarker strategies for rapid rule out of myocardial infarction in the emergency department using ACC/ESC diagnostic criteria
Authors: Collinson Paul O , Gaze David C , Morris Francis , Morris Brian , Price Alan , Goodacre Steve
Published: June 2006

Objective: Creatine kinase MB isoenzyme (CK-MB) mass and rate of change of CK-MB have been proposed as superior to cardiac troponin measurement for very early exclusion of acute myocardial infarction (AMI). All three markers were examined prospectively in patients presenting to the Emergency Department (ED) for rule out of AMI.

Methods: Consecutive admissions to the ED with undifferentiated chest pain were initially assessed clinically and by electrocardiography. A total of 786 patients (490 male, median age 52.5 years) considered at low risk of AMI had blood drawn on admission. If the first sample was less than 12 h from onset of chest pain, a second sample was then drawn at least 2 h later and at least 6 h from onset of chest pain. CK-MB mass was measured on the first sample and CK-MB mass and cardiac troponin T (cTnT) were measured on the second sample. Measurement of cTnT was using an Elecsys 2010 with the third generation assay (Roche Diagnostics, Lewes, UK). Assay coefficient of variation (CV) was 5.8% and 5.7% at 0.47 and 11.5 µg/L, respectively, with measuring range 0.01-25.0 µg/L; analytical sensitivity of 0.01 µg/L and functional sensitivity of 0.03 µg/L. CK-MB (mass) was measured by electrochemiluminesence using an Elecsys 2010 (Roche Diagnostics). The assay CV was 4.0% at 5.89 µg/L and 4.1% at 60.5 µg/L, with a detection limit of 0.1 µg/L and an upper measuring limit of 500 µg/L. Myocardial infarction was diagnosed if either sample had a CK-MB of more than 5 µg/L, if there was a change in CK-MB (∆CK-MB) of more than 1.5 µg/L or if the cTnT was more than 0.05 µg/L. When AMI was excluded, patients proceeded to stress electrocardiography and reattended 72 h from presentation for follow up phlebotomy for cTnT measurement. A final diagnosis of AMI was made according to American College of Cardiology/ European Society of Cardiology criteria using a cut-off of 0.05 μg/L cTnT in any of the samples. Diagnostic efficiency was compared by receiver operator characteristic (ROC) curve analysis with comparison of area under the curve (AUC) for four strategies: admission CK-MB measurement; 6-h post-pain CK-MB measurement; ∆CK-MB; and 6-h post-pain cTnT measurement.

Results: On admission the AUC for CK-MB was 0.830 (95% confidence interval [CI] 0.757-0.904). At 6 h post pain the respective values were: CK-MB 0.939 (95% CI 0.889-0.988); -CK-MB 0.948 (95% CI 0.906-0.990); and cTnT 0.989 (95% CI 0.966-1.0).

Conclusion: cTnT at 6 h has high diagnostic sensitivity for AMI and is superior to CK-MB mass and ∆CK-MB even using a low cut-off value.
Circadian rhythm of urinary steroid metabolites
Authors: Jerjes Walid K , Cleare Anthony J , Peters Timothy J , Taylor Norman F
Published: June 2006

Background: Samples submitted for urinary steroid profile analysis are often untimed, but influence of collection time on interpretation is unknown. We report circadian rhythms of the major steroid metabolites and derived ratios in urine collected at 3-h intervals over 24 h, after first establishing that disturbance of sleep associated with collection does not alter rhythms on the succeeding day.

Methods: Assay of steroid metabolites (gas chromatography) and creatinine in urine collections made by 10 men and 10 women every 3 h starting at 2100 for 24 h. Data were subjected to cosinor analysis.

Results: Summed cortisol and androgen metabolites exhibited significant circadian rhythms, as expected, but with a surprisingly long time-lag (maxima at around 1400). Amplitudes were different, so that the ratio cortisol/androgen metabolites also showed a significant rhythm. The ratios 5 α/5 β tetrahydrocortisol and 20-hydroxy/20-oxo cortisol metabolites showed significant rhythms which were not in phase with total cortisol metabolites, while 11-hydroxy/11-oxo cortisol metabolites showed no rhythm. There were no gender differences in time of maxima. Previously established gender differences in metabolite levels were confirmed. Creatinine levels showed no circadian rhythm.

Conclusion: Circadian variation should be considered when interpreting results from urine steroid analysis. Calculation of steroid/steroid or steroid/creatinine ratios is not informative in untimed collections.
Comparison of two prediction equations with radionuclide glomerular filtration rate: validation in routine use
Authors: Saleem Mohamed , Florkowski Christopher M , George Peter M , Woltersdorf Wolfram W W
Published: June 2006

Background: Recent guidelines recommend automatic reporting of estimated glomerular filtration rate (eGFR) using the abbreviated Modification of Diet in Renal Disease (MDRD) equation with every request for plasma creatinine. We evaluated the performance of the MDRD and Cockcroft-Gault equations in routine use compared with a radionuclide GFR method.

Method: Data collected on 601 patients aged 16-85 years who had undergone radionuclide GFR and eGFR was calculated using both equations for each patient. Calculations of bias, correlation coefficients and percentage estimates within 30% and 50% of radionuclide GFR were used in comparisons.

Results: Overall, there was no significant difference in the performance between the two equations when compared with radionuclide GFR. When all creatinine results <60 μmol/L were adjusted to 60 μmol/L, and when creatinine results <60 μmol/L were excluded, MDRD performed better than the Cockcroft-Gault equation. MDRD was also superior for prediction of radionuclide GFR of <60 mL/min/1.73 m2 ( P=0.014).

Conclusion: The abbreviated MDRD formula for eGFR is superior to the Cockcroft-Gault equation for prediction of radionuclide GFR of <60 μL/min/1.73 m2and is more accurate when creatinine results <60 μmol/L are either corrected to 60 μmol/L or excluded from eGFR calculations.
Urinary gonadotropin measurements in neonates: a valuable non-invasive method
Authors: Kuijper E A M , Houwink E J F , van Weissenbruch M M , Heij H A , Blankenstein M A , Huijser J , Martens F , Lambalk C B
Published: June 2006

Background: To measure low neonatal gonadotropin levels, a sensitive non-invasive method is optimal. The aim of the current study was to validate the Architect i2000SR, an automated immunoassay analyser for the measurement of gonadotropins in unextracted neonatal urine samples against serum gonadotropin levels as a gold standard.

Methods: Blood and urine were sampled from 30 approximately six-week-old male and female neonates undergoing elective paediatric surgery. Follicle stimulating hormone (FSH) and luteinizing hormone (LH) were measured and the urine results were corrected for creatinine.

Results: The agreement between neonatal serum and urinary FSH was 0.904 (3-5 h between samples) and 0.704 (18-20 h). For LH, the correlation coefficients were 0.785 and 0.507, respectively.

Conclusion: We conclude that gonadotropins can be reliably measured using the Architect on randomly voided, non-extracted urine samples collected from neonates by an adhesive device. Urinary gonadotropin levels are a proper reflection of the serum levels.
Biochemical monitoring of nutrition support
Authors: Shenkin Alan
Published: June 2006

Laboratory monitoring is an important part of the assessment and management of all patients requiring enteral or parenteral nutritional support. The National Institute for Health and Clinical Excellence (NICE) has recently published a report on the provision of nutrition support in hospitals and in the community. Of special relevance are the recommendations that all laboratories which support a clinical nutrition service should be part of a multidisciplinary Nutrition Support Team, and that they should ensure that there is an agreed local protocol for laboratory testing and monitoring of patients receiving nutritional support.
Predictors of elevated cardiac troponin T on admission in ST-segment elevation myocardial infarction
Authors: Rasoul Saman , Nienhuis Mark B , Ottervanger Jan Paul , Slingerland Robbert J , de Boer Menko-Jan , Dambrink Jan-Henk E , Ernst Nicolette M , Hoorntje Jan C A , Gosselink A T Marcel , Suryapranata Harry , Zijlstra Felix , van't Hof Arnoud W J
Published: June 2006

Background: In patients with ST-segment elevation acute myocardial infarction (STEMI), elevated cardiac troponin T (cTnT) on admission is associated with poorer outcomes despite early reperfusion. Presentation delay is thought to be the most important factor for the elevation of cTnT on admission. We evaluated presentation delay and other potential predictors of elevated cTnT on admission in patients treated with primary percutaneous coronary interventions (PCI) for STEMI.

Methods: CTnT was measured upon arrival in the PCI centre in 444 patients with acute STEMI. An elevated cTnT was defined as > 0.05 μg/L.

Results: The mean age was 61.7 years and patients were admitted at a median of 155 min after symptom onset. Almost 50% had an elevated cTnT on admission. Patients with a positive cTnT on admission were less likely to have successful primary PCI (87 versus 93%, P=0.048) and had significantly higher rates of one-year mortality (4.9 versus 1.3%, P=0.031). There was a significant association between presentation delay and the prevalence of elevated admission cTnT, but even patients with early presentation (<120 min after symptom onset) still had a high prevalence of elevated cTnT (33%). After multivariate analysis, apart from presentation delay, anterior MI location and higher age were independent predictors of elevated cTnT on admission.

Conclusion: In patients with STEMI, the prevalence of elevated cTnT on admission is high, even in patients with early presentation. Independent predictors of elevated cTnT on admission are presentation delay, increasing age and anterior MI location.
Urinary VMA, dopamine and the likelihood of neuroblastoma: a preferred way of reporting laboratory results?
Authors: Sies C W , Florkowski C M , Sullivan M , Mackay R , George P M
Published: June 2006

Background: Neuroblastoma patients may be classified as normal or abnormal depending on reference interval and decision points for urine catecholamine metabolites. We therefore evaluated the utility of positive likelihood ratios (LR+) based on data from patients in whom the diagnosis was suspected.

Methods: Urine samples from 249 patients (122 male, 127 female) suspected of neuroblastoma were assayed for VMA by spectrophotometry and dopamine by HPLC. Ratios of VMA to creatinine (VMA/Cr) and dopamine to creatinine (DA/Cr) were calculated and age-related median scores derived relative to patients without neuroblastoma. Receiver operator characteristic (ROC) curve analysis was undertaken for the ability of median scores to identify neuroblastoma.

Results: Of the 249 patients, there were 20 confirmed cases of neuroblastoma, with ages ranging from 0 (congenital tumour) to 8.4 years. From ROC curves, VMA/Cr was found to have an area under the curve 0.96 (95% confidence interval [CI] 0.92-0.98) compared with 0.72 (95% CI 0.66-0.77) for DA/Cr, P=0.001. At the optimal decision point for VMA/Cr, LR+ was 7.2, identifying cases with a sensitivity of 95% and a specificity of 86%, and comparing favourably with published intervals.

Conclusions: VMA/Cr is more accurate than DA/Cr for the diagnosis of neuroblastoma. Reporting LR+ may also be more informative than using reference intervals and decision points.
Overview of the clinical toxicity of mercury
Authors: Magos Laszlo , Clarkson Thomas W
Published: June 2006

Mercury is ubiquitous in the environment and therefore every human being, irrespective of age and location, is exposed to one form of mercury or another. The major source of environmental mercury is natural degassing of the earth's crust, but industrial activities can raise exposure to toxic levels directly or through the use or misuse of the liquid metals or synthesized mercurial compounds. The aim of this review is to survey differences in human exposure and in the toxicology of different forms of mercury. It covers not only symptoms and signs observed in poisoned individuals by a clinician but also subclinical effects in population studies, the final evaluation of which is the domain of statisticians.
Thyrotoxicosis presenting as hypokalaemic paralysis and hyperlactataemia in an oriental man
Authors: Al-Jubouri M A , Inkster G D , Nee P A , Andrews F J
Published: June 2006

A 35-year-old Malaysian man presented with rapid onset of flaccid quadriparesis associated with nausea and vomiting. General blood tests revealed severe hypokalaemia (serum potassium 1.5 mmol/L) and hypophosphataemia (serum phosphate 0.29 mmol/L) as a potential cause of the flaccid paralysis. Arterial blood gases showed mixed acid base disturbance of respiratory alkalosis and metabolic acidosis with hyperlactataemia. Thyrotoxic periodic paralysis (TPP) was suspected as the underlying cause of this presentation and thyroid function tests showed severe hyperthyroid results (free T4 > 77.2 pmol/L, free T3 19.3 pmol/L, thyroid-stimulating hormone [TSH] < 0.05 mIU/L). Treatment with intravenous potassium and phosphate infusion and oral propranolol resulted in rapid resolution of his symptoms. A discussion of the clinical and pathophysiological features and treatment of TPP (a very rare encounter in UK clinical practice) is presented, and to our knowledge associated hyperlactataemia has not been previously described.
Most commercial insulin assays fail to detect recombinant insulin analogues
Authors: Heald A H , Bhattacharya B , Cooper H , Ullah A , McCulloch A , Smellie S , Wark G
Published: June 2006

Insulin assays are utilized in various clinical scenarios, including the assessment of insulin therapy compliance or of suspected insulin overdose. In an interpretative exercise carried out by UK National External Quality Assessment Service (NEQAS), serum sent to the participating laboratories was spiked with 30 pmol/L of the short-acting insulin analogue Human Actrapid. Only two out of 24 participant laboratories had sufficient assay cross-reactivity with Actrapid to interpret the results as suggestive of insulin administration. The development of specific insulin assays has led to deterioration in the ability to detect non-compliance or overdose with recombinant insulin treatment. Clinicians should be aware of this significant limitation, which could lead to misdiagnosis.
Elevated amylase in childhood
Authors: Howieson Alan J , MacKinlay Gordon A
Published: June 2006

A 3-year-old boy was referred to a regional centre with an acute abdomen. On admission, his abdomen was clinically benign but an extremely high serum amylase titre noted. The patient was treated with simple observation and over the following period he was found to have an inflamed parotid gland.
Postoperative serum urea is associated with 30-day mortality in patients undergoing emergency abdominal surgery
Authors: Harten J , Hay A , McMillan D C , McArdle C S , O'Reilly D St J , Kinsella J
Published: June 2006

Background: Emergency abdominal surgery carries considerable postoperative morbidity and mortality. Hypovolaemia is considered to be a cause of renal hypoperfusion, which is associated with a decreased clearance of serum urea and creatinine. This study examines whether the perioperative serum urea and creatinine concentrations are predictors of mortality in patients undergoing emergency abdominal surgery.

Methods: Consecutive patients ( n=300) who underwent emergency abdominal surgery were studied. Age- and sex-specific reference intervals were used for the data analysis. Patients with incomplete biochemical ( n=51) or mortality data ( n=31) or with pre-existing renal failure ( n=9) were excluded from the analysis.

Results: 209 patients were analysed, of whom 162 (78%) remained alive and 47 (22%) died following surgery. The non-survivors were older ( P<0.05), had undergone more extensive surgery ( P<0.001) and were more likely to have been admitted to the intensive care unit ( P<0.001). The serum urea concentration was higher preoperatively ( P<0.05) and on day one postoperatively ( P<0.001) in the non-survivors. On multivariate logistic regression analysis, age (odds ratio [OR] 3.27, 95% confidence interval [CI] 1.43-7.47, P<0.005), severity of surgery (OR 2.21, 95% CI 1.14-4.29, P<0.019), admission to intensive care (OR 0.54, 95% CI 0.11-0.54, P<0.001), seniority of anaesthetist (OR 0.50, 95% CI 0.27-0.90, P<0.022) and day one urea (OR 3.33, 95% CI 1.39-7.99, P<0.007) were independently associated with 30-day mortality.

Conclusions: These results indicate that an increased serum urea concentration, but not serum creatinine concentration, in the postoperative period is associated with an increase in 30-day mortality in patients undergoing emergency abdominal surgery.
The hook effect: a need for constant vigilance
Authors: Jassam N , Jones C M , Briscoe T , Horner J H
Published: June 2006

The hook effect is a well-recognized problem that can occur in assays of most tumour markers, including alpha feto-protein (AFP). We present a case of hepatoblastoma in a baby. The diagnosis was delayed as a result of unrecognized 'hooking' of a very high AFP concentration in the automated immunoassay method used. The falsely low result obtained was considered normal for the patient's age and supported the diagnosis of benign haemangioendothelioma. Liaison between clinical and laboratory staff was critical in obtaining an accurate AFP result, proceeding to liver biopsy and establishing the definitive diagnosis of hepatoblastoma. While the reasons and solutions for hook effect have been well researched and published, we believe the presence of extremely high serum AFP concentration in some hepatoblastoma patients means that the hook effect remains a problem and can generate erroneously low AFP results despite assay reformulation by manufacturers. Therefore constant vigilance by laboratory staff is still needed.
High sensitivity C-reactive protein and cardiovascular disease: an association built on unstable foundations?
Authors: Sattar Naveed , Lowe Gordon D
Published: June 2006

There is considerable interest in the inflammatory hypothesis of vascular disease. Markers of inflammation predict vascular events, and inflammatory cells and molecules are critical elements within plaques and are especially prominent in unstable lesions. With respect to screening, concentrations of C-reactive protein (CRP), as determined by high-sensitivity assays, have been consistently shown to predict myocardial infarction and other vascular events independently of traditional risk factors. As a result, some authorities proposed potential inclusion of CRP in risk factor stratification. However, more recent evidence in the last two years from larger studies suggests that CRP concentrations are only around as half as predictive for vascular events as suggested in earlier reports. Furthermore, it now appears as if CRP measurements add little additional predictive value to current coronary heart disease risk prediction charts. The short-term variability of CRP is also problematic for risk factor screening. At the same time, other recent evidence questions the proposed causal role of CRP in atherogenesis. Therefore, the current focus in clinical practice should remain on established risk factors (e.g. smoking, lipids and blood pressure), both to determine coronary heart disease risk and to reduce it.
On the interpretation of affirmative follow-up tests in immunoassays: what must not be done?
Authors: Ismail Adel A A
Published: June 2006

The integrity of analyses and their limitations fall firmly within the laboratory domain. The shortcomings of analyses performed by immunoassays are well recognized. When a result is unexpected or in doubt, the laboratory may perform additional tests to substantiate the integrity of that analysis, such as repeat analysis by an alternative method, serial dilutions, or antibody blocking regents. Though commendable practice, these extra tests could in some cases lead to a false sense of assurance, misleading clinicians and wasting resources. I would like to highlight the use and misuse of these tests.
Acting global – thinking local: balancing historic marginality and political change in a small island ‘state’
Authors: Mannin Michael
Published: June 2006

English

This article focuses on the problems that one small island state has encountered in attempting to reform its political system. Jersey, an Offshore Financial Centre (OFC), has experienced considerable difficulty in responding to relatively modest reform proposals contained within the Clothier Report (States of Jersey, 2000). It is argued that these difficulties are shaped by tensions between regional and international regulatory pressures and domestic strategies to sustain autonomy to meet the perceived requirements of a globally responsive OFC economy. The management of these tensions is explained within the concept of historic marginality (Pizzorno, 1971), as well as the broader implications of political change for OFCs in general.
Employability and New Zealand welfare restructuring
Authors: Lunt Neil
Published: June 2006

English

The article discusses employability within New Zealand. It outlines a series of initiatives around welfare reform that have targeted disabled people, unemployed groups, lone parents and women reentering jobs, youth, and ethnic groupings. A fourfold critique of employability is suggested around labour market outcomes, social exclusion, human resource development and broader citizenship concerns. Situating New Zealand within the broader welfare-to-work literature, the article identifies how employability constitutes a distinct electoral strategy, and outlines the future direction employability is likely to take.
Analysing policy processes as multiple governance: accountability in social policy
Authors: Hill Michael , Hupe Peter
Published: June 2006

English

There is a need to develop appropriate ways to analyse issues about complexity in the governance process and about accountability. The preoccupation with policy ‘stages’ need to be replaced with a more complex model of the way in which policy decisions are inter-related or ‘nested’. It is argued that a ‘multiple governance framework’, influenced by Elinor Ostrom's ‘institutional analysis and development’ framework, offers a way to do this. The framework is illustrated using examples from English health and education policy, where there are opposed positions about professional autonomy and about local prerogatives, to show how this approach assists the analysis of issues like these.
Money, power and ideas: think tank development and state–business relations in Taiwan and Hong Kong
Authors: Yep Ray , Ngok Ma
Published: June 2006

English

A comparative study of Taiwan and Hong Kong shows that the business response to political changes and changing state–business relations are crucial factors in determining think tank development. Amid rapid democratisation, business tycoons in Taiwan actively fund think tanks to pursue their own policy agenda and improve their political leverage. In contrast, institution of a state–corporatist framework and arrested democratisation have perpetuated a state–business alliance in Hong Kong since 1997, resulting in weak business support for policy in the former colony.
Welfare restructuring in Asian newly industrialised countries: a comparison of Hong Kong and Singapore
Authors: Lee Eliza W.Y.
Published: June 2006

English

This article studies the patterns of welfare restructuring in Asian newly industrialised countries (NICs) in reaction to economic globalisation and socioeconomic change through a comparative study of Hong Kong and Singapore. It argues that Hong Kong has gone through a budget-driven restructuring resulting in the retrenchment of its residual welfare state, while Singapore has undergone a policy-driven restructuring that aims to consolidate the state regulation of the welfare society. The difference in the patterns of restructuring is found to be related to state strength, electoral politics, interest group politics, the production system and the pre-existing institutional arrangement of social programmes. The findings illustrate the characteristics of welfare restructuring in Asian authoritarian NICs.
Young people and political (in)activism: why don't young people vote?
Authors: Henn Matt , Weinstein Mark
Published: June 2006

English

Continued experimentation with methods to make the process of voting easier signals a growing concern among politicians that the public is becoming increasingly disaffected from politics in Britain. However, these government initiatives may be failing to tackle the real problem – that the electorate appears to find the business of politics uninviting and irrelevant. In this article we examine the results from a nationwide survey of over 700 young people, and find that this generation, while supportive of these new electoral methods, are unlikely to be persuaded to turn out to vote while they continue to feel marginalised from the political process.
Building blocks for a new social architecture: the LEGOTM paradigm of an active society
Authors: Jenson Jane , Saint-Martin Denis
Published: June 2006

English

Social policy communities now often focus on ‘new social risks’. Despite a clear preference for controlling state spending, they also consider that these risks call for ‘social investments’. Concentration on investments, activation and the future is considered an optimal anchor for redesigning their welfare systems. Convergence around three ideas prompt us to speak of a shift towards a LEGOTM paradigm: learning over the life-course; a future orientation; and the collective benefits of an active society. Just as when Keynesianism was paradigmatic, however, we recognise that divergences exist in the ways that the paradigm is implemented.