bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence of risk factors for suicide in patients prescribed venlafaxine, fluoxetine, and citalopram
Authors: Mines Daniel , Hill Deanna , Yu Holly , Novelli Laura
Published: May 2005

Purpose

Three recent observational studies reported that the risk of fatal overdose is greater with venlafaxine than SSRI use. It is not clear whether patient factors could account for this finding. We evaluated whether risk factors for suicide are more prevalent among patients prescribed venlafaxine than patients prescribed fluoxetine or citalopram.

Methods

Using data from the UK General Practice Research Database (GPRD), we identified patients who were first prescribed any of the three drugs between January 1995 and April 2002. We ascertained risk factors for suicide documented in the 1 year before that first prescription. Separate analyses compared venlafaxine (N = 27 096) and fluoxetine (N = 134 996) cohorts, and venlafaxine and citalopram (N = 52 035) cohorts.

Results

Previous suicidal behaviors were documented for 1.0% of the venlafaxine cohort compared to 0.4% of the fluoxetine cohort (OR 2.8, 95%CI: 2.4, 3.2) and 0.4% citalopram cohorts (OR 2.4, 95%CI: 2.0, 2.9). 72.5% of venlafaxine patients had been prescribed at least one other antidepressant compared to 27.6% of fluoxetine (OR 6.9, 95%CI: 6.7, 7.1) and 39.5% of citalopram (OR 4.0, 95%CI: 3.9, 4.2) patients. Venlafaxine patients were also four to six times as likely to have been previously hospitalized for depression.

Conclusion

In the UK, venlafaxine has been selectively prescribed to a patient population with a higher burden of suicide risk factors than patients prescribed fluoxetine and citalopram. Unless baseline population differences are accounted for, observational studies that compare the risk of suicide in patients receiving these agents may produce biased results. Copyright © 2005 John Wiley & Sons, Ltd.
Highly conductive new aniline copolymers: poly(aniline‐co‐aminoacetophenone)s
Authors: Savitha P , Swapna Rao P , Sathyanarayana DN
Published: May 2005

Copolymers of aniline and o‐/m‐aminoacetophenone of different compositions were synthesized by oxidative chemical copolymerization. Two different methods were employed, emulsion and inverse emulsion, with different oxidants, ammonium persulphate and benzoyl peroxide, to study the effect of synthesis conditions on the yield, solubility and conductivity of the copolymers. The copolymer compositions were determined using proton NMR spectroscopy. The reactivity ratios determined by the Finemann–Ross method indicate lower reactivity for m‐aminoacetophenone relative to aniline in the emulsion method, while the reverse holds true in the inverse emulsion method. Copolymers formed by the former pathway are random type as determined by the Finemann–Ross method. The copolymers have crystalline/amorphous morphologies and good conductivity. They exhibit enhanced solubility compared with polyaniline. Copyright © 2005 Society of Chemical Industry
Mass spectrometry‐based analytical tools for the molecular protein characterization of human plasma lipoproteins
Authors: Heller Manfred , Stalder Daniel , Schlappritzi Evelyn , Hayn Gertraud , Matter Urs , Haeberli André
Published: May 2005

Lipoproteins are a heterogeneous population of blood plasma particles composed of apolipoproteins and lipids. Lipoproteins transport exogenous and endogenous triglycerides and cholesterol from sites of absorption and formation to sites of storage and usage. Three major classes of lipoproteins are distinguished according to their density: high‐density (HDL), low‐density (LDL) and very low‐density lipoproteins (VLDL). While HDLs contain mainly apolipoproteins of lower molecular weight, the two other classes contain apolipoprotein B and apolipoprotein (a) together with triglycerides and cholesterol. HDL concentrations were found to be inversely related to coronary heart disease and LDL/VLDL concentrations directly related. Although many studies have been published in this area, few have concentrated on the exact protein composition of lipoprotein particles. Lipoproteins were separated by density gradient ultracentrifugation into different subclasses. Native gel electrophoresis revealed different gel migration behaviour of the particles, with less dense particles having higher apparent hydrodynamic radii than denser particles. Apolipoprotein composition profiles were measured by matrix‐assisted laser desorption/ionization‐mass spectrometry on a macromizer™ instrument, equipped with the recently introduced cryodetector technology, and revealed differences in apolipoprotein composition between HDL subclasses. By combining these profiles with protein identifications from native and denaturing polyacrylamide gels by liquid chromatography‐tandem mass spectrometry, we characterized comprehensively the exact protein composition of different lipoprotein particles. We concluded that the differential display of protein weight information acquired by macromizer™ mass spectrometry is an excellent tool for revealing structural variations of different lipoprotein particles, and hence the foundation is laid for the screening of cardiovascular disease risk factors associated with lipoproteins.
Selective retention of some polyaromatic hydrocarbons by highly crosslinked polymer networks
Authors: Hosoya Ken , Aoki Hiroshi , Kubo Takuya , Teramachi Masashi , Tanaka Nobuo , Haginaka Jun
Published: May 2005

Highly crosslinked polymer networks were characterized in terms of structural differences based on the crosslinked network structures with their chromatographic molecular retentivity for some polyaromatic hydrocarbons (PAHs). Because PAHs and some sterically bulky solutes were used in the chromatographic characterization, tiny differences in the crosslinked polymer networks were observed in terms of the chromatographic molecular retentivity. Ethylene dimethacrylate afforded molecular retentivity for anthracene, and this recognition ability changed with the polymerization time. In addition, 1,4‐butanediol dimethacrylate afforded molecular retentivity for pyrene, and this retentivity was larger than that for anthracene. The polymerization methods also affected the resulting polymer networks drastically. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2556–2566, 2005
Long‐term stability of an ambient self‐curable latex based on colloidal dispersions in water of two reactive polymers
Authors: Chen Xiaonong , Pelton Robert , Ruckenstein Eli
Published: May 2005

An ambient self‐curable latex (ASCL) was prepared via the blending of colloidal dispersions in water of a chloromethylstyrene‐functionalized copolymer and a tertiary‐amine‐functionalized copolymer. Upon casting and drying under ambient conditions, the ASCL could generate crosslinked continuous polymer films. The crosslinking occurred via the Menschutkin reaction (quaternization) between the two types of functional groups. Because this reaction was reversible at high temperatures, the films could be decrosslinked and hence were self‐curable. The prepared ASCL exhibited excellent colloidal and chemical stability during long‐term storage: no significant changes in the colloidal properties, such as the particle size, electrophoretic mobility, and crosslinking reactivity, were observed after 48 months of storage. The electrophoretic measurements indicated that the electrostatic repulsion between the negatively charged particles of the ASCL was responsible for the excellent stability. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2598–2605, 2005
Synthesis and modeling of new phosphorus‐containing acrylates
Authors: Salman Seyhan , Albayrak Aylin Ziylan , Avci Duygu , Aviyente Viktorya
Published: May 2005

New methacrylate monomers containing phosphonic acid or both phosphonic and carboxylic acids were synthesized through the reaction of t‐butyl α‐bromomethyl acrylate with triethyl phosphite followed by the selective hydrolysis of the phosphonate or t‐butyl ester groups with trimethylsilyl bromide and trifluoroacetic acid. The copolymerization of these monomers with 2‐hydroxyethylmethacrylate was investigated with photodifferential scanning calorimetry at 40 °C with 2,2′‐dimethoxy‐2‐phenyl acetophenone as a photoinitiator. Quantum mechanical tools were also used to understand the mechanistic behavior of the polymerization reactions of these synthesized monomers. The propagation and chain‐transfer reactions were considered and rationalized. A strong effect of the monomer structure on the rate of polymerization was observed. The polymerization reactivities of the monomers increased with decreasing steric hindrance and/or increasing hydrogen‐bonding capacity because of the hydrolysis of the phosphonate and the t‐butyl ester groups. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2574–2583, 2005
Sequence analysis of poly (ether sulfone) copolymers by 13C NMR
Authors: Zhou Xiao‐Ming , Jiang Zhen‐Hua
Published: May 2005

Random and block copolymers of poly (ether sulfone) (PES) and poly (ether ether sulfone) (PEES) were synthesized by the nucleophilic polycondensation of 4,4′‐dichlorodiphenyl sulfone (DCDPS) with 4,4′‐dihydroxydiphenyl sulfone (DHDPS) and hydroquinone (HQ). Chemical structures of these copolymers were characterized by 13C NMR. The monomer molar fraction, sequential distribution, and degree of randomness of the copolymers were determined through analyses of the resonances of quaternary carbons in the DCDPS unit. Experimental results show that the molar fractions of the comonomer determined by 13C NMR analyses are close to the charged values in the synthetic step. Moreover, these copolymers, which were prepared by different polymerization methods, revealed different number‐average sequential length and degree of randomness. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1624–1630, 2005
New method for protein secondary structure assignment based on a simple topological descriptor
Authors: Taylor Todd , Rivera Margarita , Wilson Glenda , Vaisman Iosif I.
Published: May 2005

A simple, five‐element descriptor, derived from the Delaunay tessellation of a protein structure in a single point per residue representation, can be assigned to each residue in the protein. The descriptor characterizes main‐chain topology and connectivity in the neighborhood of the residue and does not explicitly depend on putative hydrogen bonds or any geometric parameter, including bond length, angles, and areas. Rules based on this descriptor can be used for accurate, robust, and computationally efficient secondary structure assignment that correlates well with the existing methods. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Standardized ignition test procedure for evaluating antistatic flexible intermediate bulk containers (FIBC)
Authors: Britton Laurence G. , Holdstock Paul , Pappas Robert J.
Published: May 2005

In 1999 the International Electrotechnical Commission (IEC) began development of a standard for the electrostatic classification of flexible intermediate bulk containers (FIBC). Part of this effort addressed gas ignition testing for FIBC used in flammable atmospheres, drawing on test procedures used by various test laboratories. Critical examination of IEC's 2003 working draft raised a number of technical issues requiring experimental resolution. This article describes research and development leading to publication of IEC 61340‐4‐4:2005. It is shown that some FIBC previously regarded as “Type D” fail the new IEC standard test because factors such as charging current and test gas ignition energy were formerly not standardized at appropriate values. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2005
Studies on some singular potentials in quantum mechanics
Authors: Roy Amlan K.
Published: May 2005

A simple methodology is suggested for the efficient calculation of certain central potentials having singularities. The generalized pseudospectral method used in this work facilitates nonuniform and optimal spatial discretization. Applications have been made to calculate the energies, densities, and expectation values for two singular potentials of physical interest, viz., (i) the harmonic potential plus inverse quartic and sextic perturbation and (ii) the Coulomb potential with a linear and quadratic term for a broad range of parameters. The first 10 states belonging to a maximum of 𝓁 = 8 and 5 for (i) and (ii) have been computed with good accuracy and compared with the most accurate available literature data. The calculated results are in excellent agreement, especially in light of the difficulties encountered in these potentials. Some new states are reported here for the first time. This offers a general and efficient scheme for calculating these and other similar potentials of physical and mathematical interest in quantum mechanics accurately. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Algebraic modifications to second quantization for non‐Hermitian complex scaled hamiltonians with application to a quadratically convergent multiconfigurational self‐consistent field method
Authors: Yeager Danny L. , Mishra Manoj K.
Published: May 2005

The algebraic structure for creation and annihilation operators defined on orthogonal orbitals is generalized to permit easy development of bound‐state techniques involving the use of non‐Hermitian Hamiltonians arising from the use of complex‐scaling or complex‐absorbing potentials in the treatment of electron scattering resonances. These extensions are made possible by an orthogonal transformation of complex biorthogonal orbitals and states as opposed to the customary unitary transformation of real orthogonal orbitals and states and preserve all other formal and numerical simplicities of existing bound‐state methods. The ease of application is demonstrated by deriving the modified equations for implementation of a quadratically convergent multiconfigurational self‐consistent field (MCSCF) method for complex‐scaled Hamiltonians but the generalizations are equally applicable for the extension of other techniques such as single and multireference coupled cluster (CC) and many‐body perturbation theory (MBPT) methods for their use in the treatment of resonances. This extends the domain of applicability of MCSCF, CC, MBPT, and methods based on MCSCF states to an accurate treatment of resonances while still using L2 real basis sets. Modification of all other bound‐state methods and codes should be similarly straightforward. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Chiral tetrahedrons as unitary quaternions: Molecules and particles under the same standard?
Authors: Capozziello S. , Lattanzi A.
Published: May 2005

Chiral tetrahedral molecules can be dealt with under the standard of quaternionic algebra. Specifically, noncommutativity of quaternions is a feature directly related to the chirality of molecules. We show that a quaternionic representation naturally arises out from empirical Fischer projections, and the action of the related algebra on the quantum states of molecules is studied. Analogies with fundamental particle physics are discussed. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
NBO‐based CI/MP through‐space/bond interaction analysis and its application to stereoelectronic effects in SN2 reactions
Authors: Orimoto Yuuichi , Naka Kazunari , Aoki Yuriko
Published: May 2005

NBO‐based CI/MP through‐space/bond interaction analysis was developed to analyze specific orbital interactions under consideration of the effects of electron correlation. This treatment was applied to the analysis of stereoelectronic effects in SN2 reactions of allyl bromide in which the effects of electron correlation play an important role (ammonia was used as the nucleophilic reagent). The SN2 activation energy in allyl bromide is lower than that in propyl bromide, because both the σ–π* and π–σ* interactions in allyl bromide contribute equally to the stabilization of the transition state. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Fuzzy fragment selection strategies, basis set dependence and HF–DFT comparisons in the applications of the ADMA method of macromolecular quantum chemistry
Authors: Szekeres Zsolt , Exner Thomas , Mezey Paul G.
Published: May 2005

The Adjustable Density Matrix Assembler (ADMA) method is examined in this paper. This method approximates (first order) density matrices by taking only those interactions into account which are present between fragments separated by a preset distance parameter (d). The accuracy of this approximation is tested using different basis sets, distance parameters and exchange‐correlation functionals. As an illustration of the applications of the method, the electron density of the hemoglobin molecule is presented in its oxy, deoxy and carbon‐monoxy form. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
R‐matrix quantum defects of molecular hydrogen
Authors: Telmini M. , Bezzaouia S. , Jungen Ch.
Published: May 2005

The “Halfium” model, which combines the variational R‐matrix method with the methods of generalized quantum defect theory in prolate spheroidal coordinates, is illustrated for the 1Πu symmetry of molecular hydrogen. It is shown how the smooth behavior of the quantum defect matrices thus calculated permits the use of interpolation techniques that yield molecular potential energy curves, resonance positions and widths at minimal computational effort. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
DFT with effective potential expressed as a mapping of the external potential: Applications to closed‐shell molecules
Authors: Theophilou Andreas K. , Glushkov Vitaly
Published: May 2005

In density functional theory (DFT), the Kohn–Sham (KS) potential VKS is expressed in terms of the ground‐state density. As a consequence, VKS does not always have the symmetry of the external potential V. The symmetry requirements are used to derive a noninteracting potential, VeK, as a direct mapping of the external potential V. This mapping gives the following VeK for molecules and solids:

where Zi are the nuclear charges at positions Ri. An explicit form of the kernel K is given. Applications are made to small molecules (H2, LiH, BH, and H2O) in order to test its accuracy. The energies calculated were found to deviate very little from those of Hartree–Fock, as the relative deviation of the two energies, ΔE/E, was found to be of the order of 10−4. This accuracy is much higher than that of standard DFT in its local exchange potential approximation. This method is appropriate for large molecules, as it is much faster than HF and standard DFT, because the potential is known from the start. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Biometry of the pubovisceral muscle and levator hiatus by three‐dimensional pelvic floor ultrasound
Authors: Dietz H. P. , Shek C. , Clarke B.
Published: May 2005

Objective

Until recently, magnetic resonance was the only imaging method capable of assessing the levator ani in vivo. Three‐dimensional (3D) ultrasound has recently been shown to be able to demonstrate the pubovisceral muscle. The aim of this study was to define the anatomy of the levator hiatus in young nulliparous women with the help of 3D ultrasound.

Methods

In a prospective observational study, 52 nulligravid female Caucasian volunteers (aged 18–24 years) were assessed by two‐dimensional (2D) and 3D translabial ultrasound after voiding whilst supine. Pelvic organ descent was assessed on Valsalva maneuver. Volumes were acquired at rest and on Valsalva maneuver, and biometric indices of the pubovisceral muscle and levator hiatus were determined in the axial and coronal planes.

Results

In the axial plane, average diameters of the pubovisceral muscle were 0.4–1.1 cm (mean 0.73 cm). Average area measurements were 7.59 (range, 3.96–11.9) cm2. The levator hiatus at rest varied from 3.26 to 5.84 (mean 4.5) cm in the sagittal direction, and from 2.76 to 4.8 (mean 3.75) cm in the coronal plane. The hiatus area at rest ranged from 6.34 to 18.06 (mean 11.25) cm2 increasing to 14.05 (6.67–35.01) cm2 on Valsalva maneuver (P = 0.009). There were significant correlations between pelvic organ mobility and hiatus area at rest (P = 0.018 to P < 0.001) and on Valsalva maneuver (all P < 0.001).

Conclusions

Biometric indices of the pubovisceral muscle and levator hiatus can be determined by 3D ultrasound. Significant correlations exist between hiatal area and pelvic organ descent. These data provide support for the hypothesis that levator ani anatomy plays an independent role in determining pelvic organ support. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Reference ranges for serial measurements of blood velocity and pulsatility index at the intra‐abdominal portion, and fetal and placental ends of the umbilical artery
Authors: Acharya G. , Wilsgaard T. , Berntsen G. K. R. , Maltau J. M. , Kiserud T.
Published: May 2005

Objective

To construct reference ranges for serial measurements of umbilical artery (UA) blood flow velocity and pulsatility index (PI) at standardized insonation sites during the second half of pregnancy.

Methods

This was a prospective longitudinal study of the umbilical circulation. UA blood flow velocities were measured at the intra‐abdominal portion, fetal end and placental end at 4‐weekly intervals at 19–42 weeks of gestation in 130 low‐risk singleton pregnancies. A total of 513 observations were used to construct the reference ranges using regression statistics and multilevel modeling.

Results

UA blood velocities and PI were higher at the intra‐abdominal portion and fetal end than at the placental end. The gestational age‐related increase of end‐diastolic velocity was greater than the corresponding increase of the peak systolic velocity at all locations. The mean differences (delta values) of UA blood velocities between the fetal and placental ends increased and that of PI decreased with advancing gestational age.

Conclusion

UA Doppler parameters vary significantly at different locations. We have established new reference ranges for the UA velocities and PI at standardized locations based on longitudinal observations, which should be useful for the surveillance of fetuses with repeated observations. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
High variability of the metal content of tree growth rings as measured by synchrotron micro x‐ray fluorescence spectrometry
Authors: Martin Ronald R. , Naftel Steven J. , Macfie Sheila M. , Jones Keith W. , Feng Huan , Trembley Chantelle
Published: May 2005

Synchrotron radiation analysis was used to investigate the metal content of tree rings collected from paper birch,Betula papyriferaMarsh, on transects downwind from two metal smelters (nickel and copper). Individual trees reflected changes in ring metal content with time, which may be presumed to represent changes in local metal bioavailability. However, between‐tree variations were large and no statistically significant differences in metal content as a function of time were found within or between sites. Although concentrations of both total and exchangeable copper and nickel in the soil increased with proximity to the respective smelter, this pattern was reflected only in the nickel content of rings near the nickel smelter; copper content did not vary with distance from either smelter. The sites did differ with respect to lead, manganese and zinc content of the rings, which may be related to pH. In conclusion, the variability between trees at each site suggests that dendroanalysis is a poor method for evaluating metal exposure at a large (site) scale. Tree ring metal content may be used to evaluate the metal uptake by individual trees but metal mobility in the stem makes it difficult to establish a reliable chronology. Copyright © 2005 John Wiley & Sons, Ltd.
Use of micro‐PIXE to investigate otolith Sr distributions of the anadromous striped bass,Morone saxatilis
Authors: Morris James A. , Rulifson Roger A. , Babaluk John A. , May Paula G. , Campbell John L.
Published: May 2005

Migration patterns of anadromous Atlantic coast striped bass,Morone saxatilis, have been determined primarily through mark and recapture studies. These studies provide little information about the duration, seasonality and frequency of estuarine and ocean migratory phases of migration, nor have they identified the age at which striped bass first exhibit anadromy. In order to investigate how otolith Sr distributions can contribute to these aspects of fish life histories, otoliths from striped bass of the Roanoke‐Albemarle Sound, North Carolina population were analyzed using a scanning proton microprobe (micro‐PIXE). The results suggest that micro‐PIXE can provide detailed information about migration patterns for this population. Differences in striped bass migration were observed. Two fish exhibited emigration to ocean habitats at 2 years of age. Interestingly, the two movement patterns observed, one resident and one migratory, were related to the three major genotypes (mtDNA) of this population, suggesting that timing and appearance of anadromy might be related to lineage for this species. Additional sampling will be necessary in order to confirm this hypothesis. Copyright © 2005 John Wiley & Sons, Ltd.
EDXRF and TXRF application to cadmium toxicity in Acer pseudoplatanus L. cells: cytological features and cation interactions
Authors: Carvalho M. L. , Ascensão L. , Magalhães T. , Casimiro A.
Published: May 2005

Cadmium is one of the most toxic heavy metals that can be taken up by plants. Although cadmium toxicity in plants is well established, the mechanism of Cd actions at the cell level is not entirely known. The aim of this work was the investigation of Cd effects on cation contents (K, Ca, Mn, Fe, Cu, Zn) and cytological changes in sycamore cells (Acer pseudoplatanus L.). Sycamore cells were treated with 20 µM CdSO4, a sub‐lethal concentration, for 7 days. Energy‐dispersive x‐ray fluorescence (EDXRF) spectrometry was applied to quantify cation concentrations in cells. Cd concentration was measured by total reflection x‐ray fluorescence (TXRF) spectrometry. The quantification was performed with cells taken directly from the culture and also after being washed in an acidified medium. Light and scanning microscope observations showed several modifications of cadmium‐treated cells, namely increased cell volume and vacuolation. Cells exposed to cadmium also showed variations in cation concentrations. An increase in Mn, Fe, Cu and Zn contents and a decrease in K content were observed in Cd‐stressed cells. Fe was the most increased element, followed by Mn and Cu and a similar behaviour was observed for Ca and Zn. K was the only cation showing a decreased concentration under Cd stress. The high levels of Cd in cells exposed to Cd are in agreement with the amount of Cd accumulated within the cells. The results obtained allowed differentiation between adsorption of ions on the cell wall and uptake of ions into the intracellular compartments. Copyright © 2005 John Wiley & Sons, Ltd.
The new PGAA facility at the FRM II, Garching: comparison with the PIXE results obtained at the new IBA setup at Cologne
Authors: Kudějová Petra , Materna Thomas , Jolie Jan , Pascovici George
Published: May 2005

Prompt gamma‐ray activation analysis (PGAA) is proposed as a complementary non‐destructive multi‐elemental method to PIXE. At the end of 2005, a new state‐of‐the‐art PGAA facility will be built at the research reactor II (FRM II) at Garching near Munich, Germany. The facility has been moved to FRM II from the Paul Scherrer Institute (PSI), Switzerland, where it was successfully running from 1997 to 2001. The main principles, characteristics and advantages of the PGAA technique and the expectations for the redesigned PGAA facility (regarding the conditions of the FRM II) are presented. The new PIXE/IBA instrument built at the 10 MV tandem accelerator of the Nuclear Physics Institute of the University of Cologne is presented. For the detection of x‐rays, mainly a small Peltier‐cooled XFlash detector is used, which brings the advantage of its capability to acquire up to 300 kcps. The data acquisition is performed by digital electronics with a system based on DGF‐4C modules from X‐ray Instrumentation Associates (XIA) and with in‐house‐developed acquisition software. For the analysis of the spectra, the Gupix program is used. After the calibration of our PIXE instrument with thin MicroMatter standards, homogeneous powders of NIST Standard Reference Materials (SRM) were measured. The PIXE results were compared with nominal values given by NIST and with the results of the PGAA measurement at PSI in 2001. Our plan is to have at our disposal analytical methods (PIXE, PIGE, RBS, PGAA and neutron tomography) that can serve for applied research. Copyright © 2005 John Wiley & Sons, Ltd.
The importance of yeast Alr proteins in cadmium detoxification as indicated by particle‐induced x‐ray emission and phenotypic analyses
Authors: Kern A. L. , Bonatto D. , Dias J. F. , Yoneama M.‐L. , Brendel M. , Henriques J. A. P.
Published: May 2005

One gene in Saccharomyces cerevisiae, ALR1, encodes a transmembrane protein involved in the transport of Mg2+ into cells. Overexpression of this gene changes the tolerance of S. cerevisiae to several metal cations. In order to study the cellular uptake mechanism of metal cations in S. cerevisiae, an accurate determination of the metals present in the cells is needed. In this work, particle‐induced x‐ray emission (PIXE) was employed to analyze the intracellular metal content after cell exposure to cadmium. To that end, a specific method for sample preparation was developed. The samples were irradiated with a 2 MeV proton beam, while the induced x‐rays were detected with a high‐purity germanium detector. The PIXE results for cadmium‐exposed ALR1 mutant and wild‐type yeast cells suggest that Alr1p has a central role in the cell survival process in a cadmium‐rich environment. Copyright © 2005 John Wiley & Sons, Ltd.
Improvements in the analysis of calcium‐rich materials by external PIXE using selective absorbers
Authors: Güereca G. , Ruvalcaba‐Sil J. L.
Published: May 2005

For particle‐induced x‐ray emission (PIXE) spectroscopy and x‐ray fluorescence (XRF) spectrometry, the analysis of materials rich in one or two elements may present some difficulties owing to high counting rates and saturation effects in x‐ray detectors. In this case, it is possible to use selective absorbers in order to reduce significantly the intensity of the characteristic x‐rays of major elements with low attenuation for the characteristic x‐rays of other elements. For calcium‐rich materials (cements, shells, bone, teeth and stucco, for instance), the high intensity of Ca Kα, β x‐rays interferes with the detection of x‐rays of lighter and heavier elements. Compounds containing chlorine, argon and silver are good candidates for calcium‐selective absorbers, but only silver and argon absorbers may have a practical thickness when compounds of chlorine cannot be used owing to the presence of fluorescence signals from the absorber in the x‐ray spectra. A selective absorber for Ca Kα, β x‐rays using thin silver films and a flux of Ar–He was tested at an external beam setup for PIXE measurements. In this paper, the improvement in x‐ray detection is demonstrated. Copyright © 2005 John Wiley & Sons, Ltd.
Risk factors for continued illness among Gulf War veterans: a cohort study
Authors: HOTOPF M. , DAVID A. , HULL L. , NIKALAOU V. , UNWIN C. , WESSELY S.
Published: May 2005

Background. There are no prospective cohort studies of prognostic factors on the outcome of Gulf War veterans. We aimed to test the hypotheses that Gulf War veterans who were older; had more severe symptoms; had more exposures during deployment; had increased psychological distress and believed they had ‘Gulf War syndrome’ would experience greater fatigue and poorer physical functioning at follow-up.

Method. Gulf War veterans who responded to an earlier retrospective cohort study were followed with a postal survey. More symptomatic individuals were oversampled. Outcome was measured on the Chalder fatigue questionnaire, the General Health Questionnaire and the Medical Outcome Study Short-Form 36.

Results. Of those surveyed, 73·8% responded. We found some evidence for four of the five hypotheses. More self-reported exposures at baseline were not associated with poorer outcome, but older people, those with more severe symptoms at baseline, those with psychological distress and who believed they were suffering from ‘Gulf War syndrome’ had more fatigue at follow-up. Officer status was associated with a better outcome. A similar lack of association was found for exposures and physical functioning and GHQ-12 score. ‘Gulf War syndrome’ attribution was associated with a worse outcome for GHQ-12 and physical functioning even after controlling for severity of symptoms at baseline.

Conclusions. This study suggests that while multiple vaccination and military exposures are important risk factors for the onset of symptoms in Gulf War veterans, these are not important risk factors for persistence of such symptoms. Instead the severity of the initial symptoms; psychological distress and attributions may be more important determinants of outcome.
Relapse in anorexia nervosa: a survival analysis
Authors: CARTER J. C. , BLACKMORE E. , SUTANDAR-PINNOCK K. , WOODSIDE D. B.
Published: May 2005

Background. Knowledge about factors that predict relapse in anorexia nervosa (AN) is needed for the development of effective relapse prevention treatments and may also advance understanding of the psychopathology of AN. The aim of the present study was to examine the rate, timing and prediction of relapse in AN following weight restoration in a specialized in-patient treatment programme.

Method. Fifty-one consecutive first-admission AN patients who were weight-restored following in-patient treatment participated in the study. Follow-up assessments were conducted a median of 15 months post-discharge. Relapse of AN was defined as a body mass index <17·5 for 3 consecutive months. Data were analysed using Kaplan–Meier survival analysis and Cox regression.

Results. The overall rate of relapse was 35% and the mean survival time was 18 months. The highest risk period was from 6 to 17 months after discharge. Several significant predictors of relapse were identified: a history of suicide attempt; previous specialized treatment for an eating disorder; severity of obsessive–compulsive symptoms at presentation; excessive exercise immediately after discharge; and residual concern about shape and weight at discharge.

Conclusions. There continues to be a significant risk of relapse among AN patients who remain well for the first year post-discharge. Several variables were shown to be associated with an elevated risk of relapse. These findings have implications for the development of initial treatments and relapse prevention strategies for AN.
Psychosocial and illness related predictors of consultation rates in primary care – a cohort study
Authors: KAPUR N. , HUNT I. , LUNT M. , McBETH J. , CREED F. , MACFARLANE G.
Published: May 2005

Background. Despite extensive research, the reasons why patients consult their doctors are unclear. The aim of the current study was to identify the psychosocial and illness related factors that independently predicted primary care consultation over a 5-year period.

Method. We carried out a prospective, population-based cohort study with three waves of data collection by postal questionnaire in one general practice in Greater Manchester (UK). Consultation data were sought from primary care records on a random subsample of 800 adult patients. The main outcome measure was the number of consultations (including surgery and home visits) over the 5 years of the study as determined by raters blind to questionnaire responses. Questionnaire measures included the 12-item version of the General Health Questionnaire, the Illness Attitude Scales, a somatic symptom scale, a fatigue scale, a functional assessment of disability.

Results. Consultation data were obtained on 738 patients (92% of selected subjects), who accounted for 12182 consultations. Negative illness attitudes, the presence of physical and psychiatric disorder, health anxiety, changes in psychological distress, reported physical symptoms and demographic factors such as age and sex were independently associated with consultation over a 5-year period. These variables together accounted for a difference of ten consultations per year between groups.

Conclusion. Consultation in primary care is a complex behaviour with a complex aetiology. Terms such as ‘frequent attenders’ may be less helpful than recognizing a number of dimensions that operate across the whole spectrum of consultation frequency. Future research should consider the wider context of consultation.
Decisional strategies for the attribution of emotional distress in primary care
Authors: SALTINI A. , MAZZI M. A. , DEL PICCOLO L. , ZIMMERMANN C.
Published: May 2005

Background. In primary care the General Health Questionnaire (GHQ) is used to provide an independent assessment of probable caseness of psychological disorder against which to test the ability of the general practitioner (GP) to recognize patients with current emotional problems.

Method. The aim of the present study was to identify those clinical and psychosocial data on patients that increase the likelihood of GPs' attribution of emotional distress (GP model) and those that predict patients' emotional distress as defined by the GHQ-12 (GHQ model). The associations were explored using a classification tree technique (CHAID) and compared using bivariate logistic regression. Six GPs and 444 primary care patients took part.

Results. The accuracy indices of the hierarchical GP and GHQ models were 72% and 69% respectively. The availability of information on patients' psychopharmacological and psychiatric/psychological treatment in the last year was the most important predictor of attribution. Occupational, financial and housing problems and life events of loss were the most important predictors of the GHQ-12 case definition. The overall accuracy of the bivariate model was 73%. Compared with the GHQ-12, GPs gave significantly more importance to psychiatric treatment, psychopharmacological drug use and chronic illness.

Conclusions. The findings suggest that to improve the detection of current emotional distress in primary care patients GPs should pay foremost and systematic attention to social problems and recent life events of loss. These problems are important clues for the possible presence of emotional distress, whereas critical patient data, in particular psychiatric history and psychopharmacological treatment, increase the probability of attribution errors.
Are there racial differences in the way patients with psychotic disorders are treated at their first hospitalization?
Authors: SOHLER NANCY L. , BROMET EVELYN J. , LAVELLE JANET , CRAIG THOMAS J. , MOJTABAI RAMIN
Published: May 2005

Background. It is now well documented that both black and white patients with severe mental illness are likely to use different types of treatment facilities, have different lengths of hospital stays, and receive different types and dosages of psychotropic medications. It is still uncertain, however, whether these differences exist at the early stages of treatment.

Method. We examined treatment patterns for a countywide sample of patients with psychotic disorders recruited at their initial psychiatric hospitalization. Illness characteristics, prior treatment histories, admission conditions, and psychotropic medication use during this hospitalization were compared for both black and white patients.

Results. Black patients were less likely to have had out-patient treatment prior to their first hospitalization and were more likely to be hospitalized in public than in community psychiatric units than were white patients. Black patients were also more likely to be hospitalized primarily for a behavioral disturbance and escorted to the hospital by the emergency medical services or police, while white patients were more often hospitalized primarily for subjective suffering. These patterns were particularly significant for those with a non-schizophrenia diagnosis. However, there were few statistically significant differences between black and white patients on psychotropic medication use during the first hospitalization.

Conclusions. Differences during the early stages of treatment between black and white patients with psychotic disorders appear to arise most prominently before, rather than during, their first hospitalization.
The prevalence and co-morbidity of subthreshold psychiatric conditions
Authors: LEWINSOHN PETER M. , SHANKMAN STEWART A. , GAU JEFFREY M. , KLEIN DANIEL N.
Published: May 2005

Background. In previous studies of subthreshold conditions, co-morbidity has been largely ignored. The purpose was to examine rates of co-morbidity among subthreshold disorders and between subthreshold and full-syndrome disorders for the major non-psychotic classes of disorders from DSM-IV.

Method. Participants came from the Oregon Adolescent Depression Project (mean age=16·6 years; females=52·1%). On the basis of a diagnostic interview (K-SADS), participants were assigned to eight subthreshold disorders (MDD, bipolar, eating, anxiety, alcohol use, substance use, conduct, ADHD).

Results. Of the 1704 adolescents in the analyses, 52·5% had at least one subthreshood disorder. Of those, 40·0% had also experienced a co-morbid subthreshold condition, and 29·9% of those had a second co-morbid subthreshold condition. Of those with a subthreshold, 36·4% also had a full syndrome. The subthreshold forms of externalizing disorders were co-morbid with each other. As expected, subthreshold anxiety was co-morbid with subthreshold MDD but subthreshold anxiety was also co-morbid with subthreshold alcohol, conduct, and ADHD. The pattern of co-morbidities was nearly identical for males and females.

Conclusions. The hypotheses that externalizing disorders would be co-morbid with other externalizing disorders and that internalizing disorders would be co-morbid with other internalizing disorders was partially supported. Co-morbidities between subthreshold disorders and between subthreshold disorders and full syndrome should impact future research and clinical practice. The assessment of subthreshold disorders needs to include the assessment of other subthreshold and full-syndrome conditions.
Improvement in social-interpersonal functioning after cognitive therapy for recurrent depression
Authors: VITTENGL J. R. , CLARK L. A. , JARRETT R. B.
Published: May 2005

Background. Cognitive therapy reduces depressive symptoms of major depressive disorder, but little is known about concomitant reduction in social-interpersonal dysfunction.

Method. We evaluated social-interpersonal functioning (self-reported social adjustment, interpersonal problems and dyadic adjustment) and depressive symptoms (two self-report and two clinician scales) in adult outpatients (n=156) with recurrent major depressive disorder at several points during a 20-session course of acute phase cognitive therapy. Consenting acute phase responders (n=84) entered a 2-year follow-up phase, which included an 8-month experimental trial comparing continuation phase cognitive therapy to assessment-only control.

Results. Social-interpersonal functioning improved after acute phase cognitive therapy (dyadic adjustment d=0·47; interpersonal problems d=0·91; social adjustment d=1·19), but less so than depressive symptoms (d=1·55). Improvement in depressive symptoms and social-interpersonal functioning were moderately to highly correlated (r=0·39–0·72). Improvement in depressive symptoms was partly independent of social-interpersonal functioning (r=0·55–0·81), but improvement in social-interpersonal functioning independent of change in depressive symptoms was not significant (r=0·01–0·06). In acute phase responders, continuation phase therapy did not further enhance social-interpersonal functioning, but improvements in social-interpersonal functioning were maintained through the follow-up.

Conclusions. Social-interpersonal functioning is improved after acute phase cognitive therapy and maintained in responders over 2 years. Improvement in social-interpersonal functioning is largely accounted for by decreases in depressive symptoms.
Vascular disease risk factors as determinants of incident depressive symptoms: a prospective community-based study
Authors: CERVILLA J. , PRINCE M. , RABE-HESKETH S.
Published: May 2005

Background. The potential association between vascular disease and depression have been the focus for much clinical psychiatric research, although few epidemiological prospective studies have looked into this association.

Aims. This study explores the a priori hypothesis of a prospective association between cardiovascular disease or its risk factors and incident depressive symptoms.

Method. A prospective primary care based study derived from a multi-centre randomized controlled trial of moderate hypertension. 2584 moderately-hypertensive volunteers were followed-up for 54 months when five assessments of depressive symptoms, vascular disease and its risk factors were made.

Results. We found an association between the dependent variable (incident depressive symptoms measured with the Self-CARE-D) and baseline smoker status, low serum cholesterol levels, poorer cognitive function (particularly executive dysfunction), female gender and increasing age. These associations were independent of all other cardiovascular risk factors (ECG evidence of ischaemia or arrythmia, systolic or diastolic blood pressure, blood pressure decline along the trial and body mass index).

Conclusions. Our results do not support the hypothesis of a specific association between vascular disease or its risk factors and incident depressive symptoms.
Relationship of behavioural and symptomatic syndromes in schizophrenia to spatial working memory and attentional set-shifting ability
Authors: PANTELIS C. , HARVEY C. A. , PLANT G. , FOSSEY E. , MARUFF P. , STUART G. W. , BREWER W. J. , NELSON H. E. , ROBBINS T. W. , BARNES T. R. E.
Published: May 2005

Background. Behavioural syndromes (thought disturbance, social withdrawal, depressed behaviour and antisocial behaviour) offer a different perspective from that of symptomatic syndromes on the disability that may be associated with schizophrenia. Few studies have assessed their relationship with neuropsychological deficits. We hypothesized that these syndromes may represent behavioural manifestations of frontal-subcortical impairments, previously described in schizophrenia.

Method. Long-stay inpatients (n=54) and community patients (n=43) with enduring schizophrenia were assessed, using measures of symptoms and behaviour and tests of executive functioning. The relationship between syndromes and neuropsychological function was assessed using multiple regression and logistic regression analyses.

Results. Significant associations were found between performance on the spatial working memory task and the psychomotor poverty symptomatic syndrome, and between attentional set-shifting ability and both disorganization symptoms and the thought disturbance behavioural syndrome. These results were not explained by the effect of premorbid IQ, geographical location, length of illness or antipsychotic medication. Length of illness was an independent predictor of attentional set-shifting ability but not of working memory performance.

Conclusion. The specific relationship between negative symptoms and spatial working memory is consistent with involvement of the dorsolateral prefrontal cortex. The associations between difficulty with set-shifting ability and both disorganization symptoms and behaviours may reflect inability to generalize a rule that had been learned and impaired ability to respond flexibly. The specific relationship of illness duration to set-shifting ability may suggest progressive impairment on some executive tasks. The nature of these relationships and their neurobiological and rehabilitation implications are considered.