bluuebunny/crossref_metadata_2025 huggingface dataset:
The current-voltage relation for electropores with conductivity gradients
Authors: Li Jianbo , Lin Hao
Published: March 2010

In electroporation, an electric field transiently permeabilizes the cell membrane to gain access to the cytoplasm, and to deliver active agents such as DNA, proteins, and drug molecules. Past work suggests that the permeabilization is caused by the formation of aqueous, conducting pores on the lipid membrane, which are also known as electropores. The current-voltage relation across the membrane-bound pores is critical for understanding and predicting electroporation. In this work, we solve the Nernst–Planck equations in a geometry encompassing an isolated electropore to investigate this relation. In particular, we study cases where the intra- and extracellular electrical conductivities differ. We first derive an analytical solution, which is subsequently validated with a direct numerical simulation using a finite volume method. The main result of the current work is a formula for the effective pore resistance as a function of the pore radius, the membrane thickness, and the intra- and extracellular conductivities. This formula can be incorporated into whole-cell or planar-membrane electroporation models for system-level prediction and understanding.
Nuclear quantum effects in the structure and lineshapes of the N2 near-edge x-ray absorption fine structure spectrum
Authors: Fatehi Shervin , Schwartz Craig P. , Saykally Richard J. , Prendergast David
Published: March 2010

We study the relative ability of several models of x-ray absorption spectra to capture the Franck–Condon structure apparent from an experiment on gaseous nitrogen. In doing so, we adopt the Born–Oppenheimer approximation and a constrained density functional theory method for computing the energies of the x-ray-excited molecule. Starting from an otherwise classical model for the spectrum, we systematically introduce more realistic physics, first by substituting the quantum mechanical nuclear radial density in the bond separation R for the classical radial density, then by adding the effect of zero-point energy and other level shifts, and finally by including explicit rovibrational quantization of both the ground and excited states. The quantization is determined exactly, using a discrete variable representation (DVR). We show that the near-edge x-ray absorption fine structure (NEXAFS) spectrum can be predicted semiquantitatively within this framework. We also address the possibility of non-trivial temperature dependence in the spectrum. By using constrained density functional theory in combination with more accurate potentials, we demonstrate that it is possible to improve the predicted spectrum. Ultimately, we establish the predictive limits of our method with respect to vibrational fine structure in NEXAFS spectra.
Pressure driven spinning: A multifaceted approach for preparing nanoscaled functionalized fibers, scaffolds, and membranes with advanced materials
Authors: Jayasinghe Suwan N. , Suter Nicolai
Published: March 2010

Electrospinning, a flexible jet-based fiber, scaffold, and membrane fabrication approach, has been elucidated as having significance to the heath sciences. Its capabilities have been most impressive as it possesses the ability to spin composite fibers ranging from the nanometer to the micrometer scale. Nonetheless, electrospinning has limitations and hazards, negating its wider exploration, for example, the inability to handle highly conducting suspensions, to its hazardous high voltage. Hence, to date electrospinning has undergone an exhaustive research regime to a point of cliché. Thus, in the work reported herein we unveil a competing technique to electrospinning, which has overcome the above limitations and hazards yet comparable in capabilities. The fiber preparation approach unearthed herein is referred to as “pressure driven spinning (PDS).” The driving mechanism exploited in this fiber spinning process is the pressurized by-pass flow. This mechanism allows the drawing of either micro- or nanosized fibers while processing polymeric suspensions containing a wide range of advanced materials spanning structural, functional, and biological entities. Similar to electrospinning if the collection time of these continuous formed fibers is varied, composite scaffolds and membranes are generated. In keeping with our interests, multicompositional structural entities such as these could have several applications in biology and medicine, for example, ranging from the development of three-dimensional cultures (including disease models) to the development of synthetic tissues and organ structures to advanced approaches for controlled and targeted therapeutics.
State-resolved reactivity of CH4 on Pt(110)-(1×2): The role of surface orientation and impact site
Authors: Bisson Régis , Sacchi Marco , Beck Rainer D.
Published: March 2010

The reactivity of methane (CH4) on Pt(110)-(1×2) has been studied by quantum state-resolved surface reactivity measurements. Ground state reaction probabilities, S0(v=0)≅S0(laser-off), as well as state-resolved reaction probabilities S0(2ν3), for CH4 excited to the first overtone of the antisymmetric C–H stretch (2ν3) have been measured at incident translational energies in the range of 4–64 kJ/mol. We observe S0(2ν3) to be up to three orders of magnitude higher than S0(v=0), demonstrating significant vibrational activation of CH4 dissociation on Pt(110)-(1×2) by 2ν3 excitation. Furthermore, we explored the azimuthal and polar incident angle dependence of S0(2ν3) and S0(v=0) for a fixed incident translational energy Et=32 kJ/mol. For incidence perpendicular to the missing row direction on Pt(110)-(1×2) and polar angles θ>40°, shadowing effects prevent the incident CH4 molecules from impinging into the trough sites. Comparison of this polar angle dependence with reactivity data for incidence parallel to the missing rows yields state-resolved site specific reactivity information consistent with a Pt(110)-(1×2) reactivity that is dominated by top layer Pt atoms located at the ridge sites. A comparison of S0(v=0) measured on Pt(110)-(1×2) and Pt(111) yields a lower average barrier for Pt(110)-(1×2) by 13.7±2.0 kJ/mol.
Mesostructural origin of stress-induced magnetic anisotropy in Fe-based nanocrystalline ribbons
Authors: Fang Y. Z. , Zheng J. J. , Wu F. M. , Xu Q. M. , Zhang J. Q. , Ye H. Q. , Zheng J. L. , Li T. Y.
Published: March 2010

The cross-sectional mesostructure of a stress-annealed Fe-based (Fe73.5Cu1Nb3Si13.5B9) ribbon (SAR) has been investigated by atomic force microscopy. The magnetic anisotropy field was measured via the curves of the giant magnetoimpedence effect in SAR. The stress-induced magnetic anisotropy field (ΔHk) showed a linear correlation with the transverse congregating vector Kv of the agglomerated grains. This indicated that the ΔHk originated from the directional congregation of the agglomerated grains formed in SAR. A model for this directional congregation has been established. The previous diverse viewpoints on the mechanism of stress-induced magnetic anisotropy have been unified in this model.
Observation of domain structure in 001 orientated NaNbO3 films deposited on (001)SrTiO3 substrates by laser beam scanning microscopy
Authors: Yamazoe Seiji , Sakurai Hiroyuki , Saito Takehisa , Wada Takahiro
Published: March 2010

A laser beam scanning microscope (LSM) was used to observe the domain structure of 001 orientated NaNbO3 (NN) films on SrRuO3/(001)SrTiO3 substrates. The LSM micrograph clearly showed the domains and the domain walls of NN film. Using a polarization plate revealed that the deposited NN film had antiferroelectric 90° domains separated by {100} domain walls. When 001 orientated NN film was applied by an electric field, the 90° domains and the {100} domain walls disappeared and a new domain structure and {110} domain walls were created. This drastic change is due to the formation of new 60° domains.
Fe diffusion, oxidation, and reduction at the CoFeB/MgO interface studied by soft x-ray absorption spectroscopy and magnetic circular dichroism
Authors: Hindmarch A. T. , Dempsey K. J. , Ciudad D. , Negusse E. , Arena D. A. , Marrows C. H.
Published: March 2010

We have studied the effect of annealing on the interface magnetization in a CoFeB/MgO structure which models the lower electrode in a magnetic tunnel junction device. We find that MgO deposition causes Fe to diffuse toward the CoFeB/MgO interface, where it preferentially bonds with oxygen to form a Fe-O-rich interfacial region with reduced magnetization. After annealing at 375 °C the compositional inhomogeneity remains; Fe is reduced back to a ferromagnetic metallic state and the full interfacial magnetization is regained.
Enhanced terahertz emission from a multilayered low temperature grown GaAs structure
Authors: Rihani Samir , Faulks Richard , Beere Harvey E. , Farrer Ian , Evans Michael , Ritchie David A. , Pepper Michael
Published: March 2010

We report the use of a multilayered structure comprising of alternating layers of low temperature grown GaAs and high temperature grown AlAs, as a terahertz (THz) photoconductive antenna emitter and receiver. Devices based on 10×10 μm2 mesa defined photoconductive gaps were fabricated on the multilayered structure, and a comparison made to conventional planar devices. The mesa defined photoconductive antennas allowed successive contact through the multilayered structure, which resulted in an increase in THz emission power and detection responsivity with increasing number of layers in contact with the antenna electrodes. A comparison with a conventional single layered device, processed in an identical mesa geometry, confirmed that the enhancement in THz emission is solely due to the multilayered nature of the device, whereas the improved receiver performance can be partially attributed to the mesa geometry.
Optically and thermally manipulated spin transport through a quantum dot
Authors: Ying Yibo , Jin Guojun
Published: March 2010

We study the associated effects of polarized light and temperature bias on the charge and spin transport through a semiconductor quantum dot connected to two ferromagnetic electrodes. A spin-dependent thermoelectric current is generated in such a system, and a totally pure spin current can be obtained without an accompanying charge current. Furthermore, the sign reversal of tunnel magnetoresistance is found, which is induced by temperature difference and Rabi frequency.
Doping behavior of phosphorus in ZnO thin films: Effects of doping concentration and postgrowth thermal annealing
Authors: Liu H. F. , Chua S. J.
Published: March 2010

Effects of phosphorus concentration, [P], and postgrowth annealing on the x-ray diffraction and Raman scattering from ZnO:P thin films are presented. The ZnO (0002) diffraction peak exhibits a large monotonic angular shift with increasing [P] up to 5.1×1019 cm−3 while its shift upon annealing is dependent on [P]. No extrinsic phases were detected for the samples studied. Raman spectra reveal disorder-activated vibrational modes, around 276, 510, 582, and 643 cm−1, with increasing [P]. They also reveal local vibrational modes corresponding to PO (∼370 cm−1) and PZn (∼482 cm−1) upon annealing. The intensity evolution of the Raman features, together with the x-ray diffraction results, indicates that phosphorus substituting for zinc is favored at low annealing temperatures while increasing annealing temperature tends to convert phosphorus doping configurations from PZn to PO.
Observation of space charge limited current by Cu ion drift in porous low-k/Cu interconnects
Authors: Chen L. S. , Bang W. H. , Park Young-Joon , Ryan E. Todd , King Sean , Kim Choong-Un
Published: March 2010

This letter reports the observation of the space charge limited current (SCLC) induced by injection and drift of Cu ions into porous low-k dielectrics. The SCLC, characterized by the momentary rise and fall of current with time, is found in all Cu interconnects having defective Ta barrier while it is absent in interconnects with intact barrier. This observation, combined with existing model on SCLC, leads to the conclusion that Cu ions can be injected through defects in Ta barrier and drift under electric field with the mobility as high as an order of 10−13 cm2/sec V at room temperature.
Hexagonal BaTi1−xCoxO3 phase stabilized by Co dopants
Authors: Li Yuanyuan , Liu Qinghua , Yao Tao , Pan Zhiyun , Sun Zhihu , Jiang Yong , Zhang Hong , Pan Zijia , Yan Wensheng , Wei Shiqiang
Published: March 2010

The phase transition from tetragonal to hexagonal of crystalline BaTi1−xCoxO3 (0.01≤x≤0.20) powders prepared by solid state reaction has been studied by x-ray diffraction and x-ray absorption fine structure (XAFS). At the low Co doping level of x≤0.03, the structure of the samples is tetragonal, and it is transformed gradually to a hexagonal structure upon increasing Co content to ≥0.05. The detailed analysis of Co K-edge XAFS indicated unambiguously that the doped Co ions are substantially incorporated into the BaTiO3 host and likely serve as a trigger in leading the structure transition. On the basis of the formation energy calculations, we find that there exists a critical Co concentration in the x range of 0.027–0.055 for inducing the tetragonal-to-hexagonal structure transition of BaTi1−xCoxO3, in good agreement with the experimental observations.
Electron beam induced current investigations of Pt/SrTiO3−x interface exposed to chemical and electrical stresses
Authors: Jiang W. , Evans D. , Bain J. A. , Skowronski M. , Salvador P. A.
Published: March 2010

Pt Schottky contacts were fabricated on oxygen deficient SrTiO3−x [001] single crystals. Electron beam induced current (EBIC) and atomic force microscopy images taken on etched SrTiO3 (001) surfaces revealed that the dark {001} oriented lines observed in EBIC correlate with arrays of dislocation etch pits. Annealing contacts in air (at 120 °C for 10 min) changed the dislocation-related EBIC contrast from dark to bright. Electrically stressing the air-annealed Schottky contacts at −10 V for 1 h caused the dislocation-related EBIC contrast to return to dark. The contrast changes are interpreted as arising from oxygen vacancy motion in response to chemical or electrical stresses.
Magneto-optical properties of cobalt slanted columnar thin films
Authors: Schmidt Daniel , Hofmann Tino , Herzinger Craig M. , Schubert Eva , Schubert Mathias
Published: March 2010

Magneto-optical properties of ferromagnetic slanted columnar thin films from cobalt made by electron-beam glancing angle deposition are reported. Magneto-optic ellipsometry in the polar Kerr effect configuration was employed to determine the field- and wavelength-dependent complex magneto-optic polarizability parameter within the spectral range from 0.74 to 3.0 eV. Kerr effect measurements and calculations reveal a strong azimuthal dependence for the incident linear polarization with peak Kerr rotation one order of magnitude larger than what has been reported for solid Co thin films.
Ultralow-threshold field emission from oriented nanostructured GaN films on Si substrate
Authors: Zhao Wei , Wang Ru-Zhi , Song Xue-Mei , Wang Hao , Wang Bo , Yan Hui , Chu Paul K.
Published: March 2010

A series of nanostructured GaN Films have been prepared on Si substrates. Field emission measurements show that the oriented nanostructured GaN film with a thickness of 40 nm has an ultralow threshold field of 1.2 V/μm at 1 mA/cm2 and yields a stable emission current of 40 mA/cm2 at 2.8 V/μm, which is comparable to those of carbon nanotubes. A polarization field emission enhancement mechanism with ballistic electron transport is proposed to explain the origin of this ultralow-threshold field emission phenomenon.
A genome-wide association study of alcohol dependence
Authors: Bierut Laura J. , Agrawal Arpana , Bucholz Kathleen K. , Doheny Kimberly F. , Laurie Cathy , Pugh Elizabeth , Fisher Sherri , Fox Louis , Howells William , Bertelsen Sarah , Hinrichs Anthony L. , Almasy Laura , Breslau Naomi , Culverhouse Robert C. , Dick Danielle M. , Edenberg Howard J. , Foroud Tatiana , Grucza Richard A. , Hatsukami Dorothy , Hesselbrock Victor , Johnson Eric O. , Kramer John , Krueger Robert F. , Kuperman Samuel , Lynskey Michael , Mann Karl , Neuman Rosalind J. , Nöthen Markus M. , Nurnberger John I. , Porjesz Bernice , Ridinger Monika , Saccone Nancy L. , Saccone Scott F. , Schuckit Marc A. , Tischfield Jay A. , Wang Jen C. , Rietschel Marcella , Goate Alison M. , Rice John P. ,   as part of the Gene, Environment Association Studies (GENEVA) Consortium
Published: March 2010

Excessive alcohol consumption is one of the leading causes of preventable death in the United States. Approximately 14% of those who use alcohol meet criteria during their lifetime for alcohol dependence, which is characterized by tolerance, withdrawal, inability to stop drinking, and continued drinking despite serious psychological or physiological problems. We explored genetic influences on alcohol dependence among 1,897 European-American and African-American subjects with alcohol dependence compared with 1,932 unrelated, alcohol-exposed, nondependent controls. Constitutional DNA of each subject was genotyped using the Illumina 1M beadchip. Fifteen SNPs yielded
P
< 10
−5
, but in two independent replication series, no SNP passed a replication threshold of
P
< 0.05. Candidate gene
GABRA2
, which encodes the GABA receptor α2 subunit, was evaluated independently. Five SNPs at
GABRA2
yielded nominal (uncorrected)
P
< 0.05, with odds ratios between 1.11 and 1.16. Further dissection of the alcoholism phenotype, to disentangle the influence of comorbid substance-use disorders, will be a next step in identifying genetic variants associated with alcohol dependence.
Population genetics of ecological communities with DNA barcodes: An example from New Guinea Lepidoptera
Authors: Craft Kathleen J. , Pauls Steffen U. , Darrow Karolyn , Miller Scott E. , Hebert Paul D. N. , Helgen Lauren E. , Novotny Vojtech , Weiblen George D.
Published: March 2010

Comparative population genetics of ecological guilds can reveal generalities in patterns of differentiation bearing on hypotheses regarding the origin and maintenance of community diversity. Contradictory estimates of host specificity and beta diversity in tropical Lepidoptera (moths and butterflies) from New Guinea and the Americas have sparked debate on the role of host-associated divergence and geographic isolation in explaining latitudinal diversity gradients. We sampled haplotypes of mitochondrial cytochrome
c
oxidase I from 28 Lepidoptera species and 1,359 individuals across four host plant genera and eight sites in New Guinea to estimate population divergence in relation to host specificity and geography. Analyses of molecular variance and haplotype networks indicate varying patterns of genetic structure among ecologically similar sympatric species. One-quarter lacked evidence of isolation by distance or host-associated differentiation, whereas 21% exhibited both. Fourteen percent of the species exhibited host-associated differentiation without geographic isolation, 18% showed the opposite, and 21% were equivocal, insofar as analyses of molecular variance and haplotype networks yielded incongruent patterns. Variation in dietary breadth among community members suggests that speciation by specialization is an important, but not universal, mechanism for diversification of tropical Lepidoptera. Geographically widespread haplotypes challenge predictions of vicariance biogeography. Dispersal is important, and Lepidoptera communities appear to be highly dynamic according to the various phylogeographic histories of component species. Population genetic comparisons among herbivores of major tropical and temperate regions are needed to test predictions of ecological theory and evaluate global patterns of biodiversity.
Do increased resources increase educational attainment during a period of rising expenditure? Evidence from English secondary schools using a dynamic panel analysis
Authors: Pugh Geoff , Mangan Jean , Gray John
Published: March 2010

This article estimates the effects of school expenditure on school performance at Key Stage 4 in England, over the period 2003–07 during which real per pupil expenditure increased rapidly. It adds to previous investigations by using dynamic panel analysis to: exploit time series data on individual schools that only recently has become available; adjust for the potential endogeneity not only of expenditure but also of other determinants of performance; and differentiate the short‐run and the (higher) long‐run attainment effects of spending changes. Consistent with other recent work, the article reports a generally significant but small effect of expenditure on school performance, but it also finds that the effect varies between specialist and non‐specialist schools, with the effect on the latter being larger. Further, the article identifies significant dynamics in the school improvement process, quantifies the long‐run effect of expenditure changes, suggests that spending effects increase with socio‐economic disadvantage, and quantifies absence effects.
The potential balm of religion and spirituality for recovering from ostracism
Authors: Wesselmann Eric D. , Williams Kipling D.
Published: March 2010

Ostracism – being ignored and excluded – is a common and painful experience with negative psychological consequences. We present a social psychological conceptualization of ostracism, and review the extensive research conducted on this phenomenon during the past fifteen
years. We discuss this research within a stage model that examines the effects of ostracism over time. This model argues that immediate reactions to ostracism are ubiquitous and largely uniform, but various coping procedures become more important after individuals have had time to reflect
upon their experiences. We suggest that individuals who are coping with ostracism may find their spiritual beliefs useful in their recovery. However, spiritual coping may be exploited by opportunistic proselytizers for cults or other dubious groups. We suggest that workplace spirituality may
be another method of recovery that can be encouraged by organizations that wish to remain secular and respect those employees who do not have spiritual affiliations.
Integrable (2+1)-dimensional and (3+1)-dimensional breaking soliton equations
Authors: Wazwaz Abdul-Majid
Published: March 2010

In this work, integrable (2+1)-dimensional and integrable (3+1)-dimensional breaking soliton equations are examined. The modified form of Hirota's bilinear method, established by Hereman, is applied to derive multiple soliton solutions and multiple singular soliton solutions for each model. The resonance phenomenon does not exist for the two models.
Generation of exactly solvable quantum potentials in D-dimensional space
Authors: Saikia N , Ahmed S A S
Published: March 2010

Exactly solved quantum potentials are obtained using the extended transformation technique within the framework of Green's functions, in any chosen D-dimensional space. Bound state solutions of the exactly solved potentials are given. It is shown that the bound state eigenfunctions of the generated quantum system can be easily normalized in most cases.
Gravitomagnetic corrections on gravitational waves
Authors: Capozziello S , De Laurentis M , Forte L , Garufi F , Milano L
Published: March 2010

Gravitational waveforms and production can be considerably affected by gravitomagnetic corrections considered in the relativistic theory of orbits. Besides the standard periastron effect of general relativity, new nutation effects arise when c
−3 corrections are taken into account. Such corrections emerge as soon as matter-current densities and vector gravitational potentials cannot be discarded into dynamics. We study the gravitational waves (GWs) emitted through the capture, in the gravitational field of massive binary systems (e.g. a very massive black hole on which a stellar object is inspiralling) via the quadrupole approximation, considering precession and nutation effects. We present a numerical study to obtain GW luminosity, total energy output and gravitational radiation amplitude. From a crude estimate of the expected number of events toward peculiar targets (e.g. globular clusters) and, in particular, the rate of events per year for dense stellar clusters at the Galactic Center (Sagittarius region (SgrA*)), we conclude that this type of capture could give signatures to be revealed by interferometric GW antennas, in particular by the forthcoming laser interferometer space antenna (LISA).
LRPPRC and SLIRP Interact in a Ribonucleoprotein Complex That Regulates Posttranscriptional Gene Expression in Mitochondria
Authors: Sasarman Florin , Brunel-Guitton Catherine , Antonicka Hana , Wai Timothy , Shoubridge Eric A. ,   LSFC Consortium
Published: March 2010

Mutations in LRPPRC are responsible for the French Canadian variant of Leigh syndrome (LSFC), a neurodegenerative disorder caused by a tissue-specific deficiency in cytochrome c oxidase (COX). To investigate the pathogenic mechanism of disease, we studied LRPPRC function in LSFC and control fibroblasts. The level of mutated LRPPRC is reduced in LSFC cells, and this results in decreased steady-state levels of most mitochondrial mRNAs, but not rRNAs or tRNAs, a phenotype that can be reproduced by siRNA-mediated knockdown of LRPPRC in control cells. Processing of the primary transcripts appears normal. The resultant defect in mitochondrial protein synthesis in LSFC cells disproportionately affects the COX subunits, leading to an isolated COX assembly defect. Further knockdown of LRPPRC produces a generalized assembly defect in all oxidative phosphorylation complexes containing mtDNA-encoded subunits, due to a severe decrease in all mitochondrial mRNAs. LRPPRC exists in a high-molecular-weight complex, and it coimmunoprecipitates with SLIRP, a stem-loop RNA-binding protein. Although this interaction does not depend on mitochondrial mRNA, both proteins show reduced stability in its absence. These results implicate LRPPRC in posttranscriptional mitochondrial gene expression as part of a ribonucleoprotein complex that regulates the stability and handling of mature mRNAs.
Modeling the Effects of Restricting Packer‐Owned Livestock in the U.S. Swine Industry
Authors: Wohlgenant Michael K.
Published: March 2010

An imperfectly competitive model of processor (packer) behavior is formulated to estimate welfare effects from restricting alternative marketing arrangements of livestock procured by packers. Pork was aggregated into a composite good and hog supply was partitioned into negotiated (spot), contract, and packer‐owned. The model was estimated with the dynamic SUR method using weekly Mandatory Price Reporting (MPR) hog and pork data from 2001 to 2005. The model incorporates production uncertainty by modeling expected pork output as expected output in the input demand functions. The welfare effects from banning packer‐owned hogs indicate that independent producers, consumers, and packers all would lose.
Prognostic implications of functional mitral regurgitation according to the severity of the underlying chronic heart failure: a long‐term outcome study
Authors: Bursi Francesca , Barbieri Andrea , Grigioni Francesco , Reggianini Letizia , Zanasi Vera , Leuzzi Chiara , Ricci Caterina , Piovaccari Giulia , Branzi Angelo , Modena Maria Grazia
Published: March 2010

Aims

To examine the independent prognostic role of functional mitral regurgitation (FMR) and its impact across the severity of chronic heart failure (CHF) in a large population of outpatients with systolic CHF followed at two multidisciplinary clinics.

Methods and results

Echocardiography was performed upon enrolment in 469 CHF patients. Follow‐up for death and heart transplant was updated on January 2007. Five‐year transplant‐free survival was 82.7% in patients with no or Grade I FMR, 64.4% in Grade II, 58.5% in Grade III, and 46.5% in Grade IV (P < 0.0001). There was a strong graded association between FMR and the long‐term risk of death and heart transplant, which remained significant after multivariable adjustment (P = 0.0003). The association between FMR and events was strong and independent in patients with less severe symptoms and in those at lower overall risk based on a propensity score analysis, while it was not significant in patients with more advanced CHF or in the high‐risk subgroup (P < 0.0001 for interactions).

Conclusion

This study clarifies previous apparently discrepant results by demonstrating that FMR is an independent determinant of death and heart transplantation only in less severe CHF and in patients with a lower risk profile. This finding indicates that FMR plays a major role in the early phase of CHF, suggesting that this should be the focus of strategies attempting to reduce it.
Critical elements of clinical follow‐up after hospital discharge for heart failure: insights from the EVEREST trial
Authors: Dunlay Shannon M. , Gheorghiade Mihai , Reid Kimberly J. , Allen Larry A. , Chan Paul S. , Hauptman Paul J. , Zannad Faiez , Maggioni Aldo P. , Swedberg Karl , Konstam Marvin A. , Spertus John A.
Published: March 2010

Aims

Hospitalized heart failure (HF) patients are at high risk for death and readmission. We examined the incremental value of data obtained 1 week after HF hospital discharge in predicting mortality and readmission.

Methods and results

In the Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study with tolvaptan, 1528 hospitalized patients (ejection fraction ≤40%) with a physical examination, laboratories, and health status [Kansas City Cardiomyopathy Questionnaire (KCCQ)] assessments 1 week after discharge were included. The ability to predict 1 year cardiovascular rehospitalization and mortality was assessed with Cox models, c‐statistics, and the integrated discrimination improvement (IDI). Not using a beta‐blocker, rales, pedal oedema, hyponatraemia, lower creatinine clearance, higher brain natriuretic peptide, and worse health status were independent risk factors for rehospitalization and death. The c‐statistic for the base model (history and medications) was 0.657. The model improved with physical examination, laboratory, and KCCQ results, with IDI increases of 4.9, 7.0, and 3.2%, respectively (P < 0.001 each). The combination of all three offered the greatest incremental gain (c‐statistic 0.749; IDI increase 10.8%).

Conclusion

Physical examination, laboratories, and KCCQ assessed 1 week after discharge offer important prognostic information, suggesting that all are critical components of outpatient evaluation after HF hospitalization.
Coexpression network analysis of neural tissue reveals perturbations in developmental processes in schizophrenia
Authors: Torkamani Ali , Dean Brian , Schork Nicholas J. , Thomas Elizabeth A.
Published: March 2010

We performed integrated gene coexpression network analysis on two large microarray-based brain gene expression data sets generated from the prefrontal cortex obtained post-mortem from 101 subjects, 47 subjects with schizophrenia and 54 normal control subjects, ranging in age from 19 to 81 years. Twenty-eight modules of coexpressed genes with functional interpretations were detected in both normal subjects and those with schizophrenia. Significant overlap of “case” and “control” module composition was observed, indicating that extensive differences in underlying molecular connectivity are not likely driving pathology in schizophrenia. Modules of coexpressed genes were characterized according to disease association, cell type specificity, and the effects of aging. We find that genes with altered expression in schizophrenia clustered into distinct coexpression networks and that these were associated primarily with neurons. We further identified a robust effect of age on gene expression modules that differentiates normal subjects from those with schizophrenia. In particular, we report that normal age-related decreases in genes related to central nervous system developmental processes, including neurite outgrowth, neuronal differentiation, and dopamine-related cellular signaling, do not occur in subjects with schizophrenia during the aging process. Extrapolating these findings to earlier stages of development supports the concept that schizophrenia pathogenesis begins early in life and is associated with a failure of normal decreases in developmental-related gene expression. These findings provide a novel mechanism for the “developmental” hypothesis of schizophrenia on a molecular level.
Subjective social status affects smoking abstinence during acute withdrawal through affective mediators
Authors: Reitzel Lorraine R. , Mazas Carlos A. , Cofta‐Woerpel Ludmila , Li Yisheng , Cao Yumei , Businelle Michael S. , Cinciripini Paul M. , Wetter David W.
Published: March 2010

Objectives  Direct and mediated associations between subjective social status (SSS), a subjective measure of socio‐economic status, and smoking abstinence were examined during the period of acute withdrawal among a diverse sample of 421 smokers (33% Caucasian, 34% African American, 33% Latino) undergoing a quit attempt.

Methods  Logistic regressions examined relations between SSS and abstinence, controlling for socio‐demographic variables. Depression, stress, positive affect and negative affect on the quit day were examined as potential affective mediators of the SSS‐abstinence association, with and without adjusting for pre‐quit mediator scores.

Results  SSS predicted abstinence to 2 weeks post‐quit. Abstinence rates were 2.6 (postquit week 1) and 2.4 (postquit week 2) times higher in the highest versus the lowest SSS quartile. Depression and positive affect mediated the SSS–abstinence relationships, but only depression maintained significance when adjusting for the baseline mediator score.

Conclusions  Among a diverse sample of quitting smokers, low SSS predicted relapse during acute withdrawal after controlling for numerous covariates, an effect accounted for partially by quit day affective symptomatology. Smokers endorsing lower SSS face significant hurdles in achieving cessation, highlighting the need for targeted interventions encompassing attention to quit day mood reactivity.
Effectiveness of a hospital‐based vascular screening programme (SMART) for risk factor management in patients with established vascular disease or type 2 diabetes: a parallel‐group comparative study
Authors: Brouwer B. G. , Visseren F. L. J. , Algra A. , Van Bockel J. H. , Bollen E. L. E. M. , Doevendans P. A. , Greving J. P. , Kappelle L. J. , Moll F. L. , Pijl H. , Romijn J. A. , Van Der Wall E. E. , Van Der Graaf Y.
Published: March 2010

Abstract.  Brouwer BG, Visseren FLJ, Algra A, van Bockel JH, Bollen ELEM, Doevendans PA, Greving JP, Kappelle LJ, Moll FL, Pijl H, Romijn JA, van der Wall EE, van der Graaf Y (University Medical Center Utrecht, Utrecht; and Leiden University Medical Center, Leiden; the Netherlands). Effectiveness of a hospital‐based vascular screening programme (SMART) for risk factor management in patients with established vascular disease or type 2 diabetes: a parallel‐group comparative study. J Intern Med 2010; 268:83–93.

Aims.  Modification of vascular risk factors is effective in reducing mortality and morbidity in patients with symptomatic atherosclerosis; however, it is difficult to achieve and maintain. The aim of the Risk management in Utrecht and Leiden Evaluation (RULE) study was to assess risk factor status after referral in patients with established vascular disease or type 2 diabetes who took part in the multidisciplinary hospital‐based vascular screening programme, Second Manifestations of ARTerial disease, compared with a group who did not participate in such a programme.

Methods and results.  Patients with type 2 diabetes, coronary artery disease, cerebrovascular disease or peripheral arterial disease referred by general practitioners to the medical specialist at the University Medical Center (UMC) Utrecht (a setting with a vascular screening programme of systematic screening of risk factors followed by treatment advice) and the Leiden UMC (a setting without such a screening programme), were enrolled in the study. Blood pressure, levels of lipids, glucose and creatinine, weight, waist circumference and smoking status were measured in patients 12–18 months after referral to the two hospitals.

A total of 604 patients were treated in the setting with a vascular screening programme and 566 in the setting without such a programme; 70% of all patients were male, with a mean age of 61 ± 10 years. Amongst screened patients, systolic blood pressure [2.5 mmHg, 95% confidence interval (CI) 0.3–4.6] and the level of LDL cholesterol (0.3 mmol L−1, 95% CI 0.2–0.4) were lower compared with the group that received usual care, after a median of 16 months from referral.

Conclusion.  Systematic screening of risk factors, followed by evidence‐based, tailored treatment advice contributed to slightly better risk factor reduction in patients with established vascular disease or type 2 diabetes. However, a large proportion of patients did not reach the treatment goals according to (inter)national guidelines. Systematic screening of vascular risk factors alone is not enough for adequate risk factor management in high‐risk patients.
Epidemiology and prevention of hepatitis B virus infection in China
Authors: Lu F. M. , Li T. , Liu S. , Zhuang H.
Published: March 2010

Summary.  The concept of a hepatitis B vaccine was first introduced into China in 1978. China has been one of the first two developing countries to enact the universal hepatitis B vaccination programme for newborn babies in 1992, and has made tremendous achievements in the control of hepatitis B virus (HBV) infection since then. China now has both low and high endemic regions regarding HBV prevalence co‐existing. Although China’s drive to stop HBV spread has resulted in changes in HBV epidemic patterns, for the eventual elimination HBV infection in China, it is important to understand the current status of its epidemiology and the aspects of HBV transmission in different regions. More efforts are needed to improve and develop strategies for the control of HBV infection in China, particularly after implementing the policy of universal HBV immunization for all newborns.
Significant histopathology in Chinese chronic hepatitis B patients with persistently high–normal alanine aminotransferase
Authors: Gui H. L. , Wang H. , Yang Y. H. , Wu Y. W. , Zhou H. J. , Guo S. M. , Lin L. Y. , Wang L. , Cai W. , Chen R. , Guo Q. , Zhou X. Q. , Bao S. S. , Xie Q.
Published: March 2010

Summary.  Current guidelines recommend antiviral therapy for chronic hepatitis B (CHB) patients with elevated alanine aminotransferase (ALT) and high viral load. Scant histological data exist for CHB patients with persistently normal ALT (PNALT) because disease progression is thought to be rare. To identify potential predictors of significant histology in the presence of PNALT, we compared the clinical characteristics and histology of Chinese CHB PNALT patients to those in patients with elevated ALT. Percutaneous liver biopsy was performed in 522 CHB patients with Chinese ethnicity who had not had antiviral treatment. Differences in age, ALT, viral load, hepatitis B e antigen (HBeAg) status and liver histology were compared between eligible PNALT (252) and elevated ALT (270) patients. Of the PNALT patients, 38.5% had normal liver histology, 25.4% had significant necroinflammation and/or fibrosis and 8.4% had established cirrhosis. Furthermore, histopathological differences between patients with high–normal ALT (0.5–1.0 × the upper limit of normal (ULN)) and low–normal ALT (≤0.5 × ULN) were evaluated. There was a significantly greater prevalence of histopathology in the high–normal group (40.0%) than in the low–normal group (16.6%) (P < 0.001). Multiple logistic regression identified that significant histopathology findings in PNALT patients correlated with age (P < 0.001) and ALT level (P < 0.001), with age >40 years and ALT >0.5 × ULN predicting significant histopathology. Our data indicate that liver biopsy is recommended in CHB patients >40 years of age, particularly when their ALT is 0.5–1.0 × ULN. The findings above provide evidence for indication of antiviral therapy in patients with PNALT and significant histopathological change.
Management of chronic hepatitis B: experience from China
Authors: Sun J. , Hou J. L.
Published: March 2010

Summary.  Chronic hepatitis B infection is a significant health problem throughout the world, and particularly in China. It is estimated that more than half a million Chinese people die annually from end‐stage hepatitis B complications, which is associated with huge healthcare costs and a heavy socioeconomic burden. In China, the implementation of a hepatitis B vaccination programme has come into effect, and there has been a one‐third decrease of the hepatitis B virus (HBV) carrier population since 1992. This great achievement changes China from a highly endemic area for HBV infection to an intermediate one. The predominant HBV genotypes in China are B and C, which might predispose patients to a poor antiviral response. Patients and physicians from China have been actively involved in the global research into and development of new antiviral agents. Patients have been recruited for global and domestic clinical trials on antiviral agents, including lamivudine, adefovir dipivoxil, entecavir, telbivudine and two pegylated interferon‐α. In the future, more important data, focussing on optimization of the efficacy of antiviral agents, will be released from China, based on the newly launched National Eleven Five Plan Project on Hepatitis Research. Both economic development and healthcare system reform, including a new reimbursement policy, will make antiviral agents more accessible to Chinese patients. Ultimately, this will allow physicians greater opportunities to follow international and Chinese treatment recommendations.
The Effect of Male Incubation Feeding, Food and Temperature on the Incubation Behaviour of New Zealand Robins
Authors: Boulton Rebecca L. , Richard Yvan , Armstrong Doug P.
Published: March 2010

Because of finite resources, organisms face conflict between their own self‐care and reproduction. This conflict is especially apparent in avian species with female‐only incubation, where females face a trade‐off between time allocated to their own self‐maintenance and the thermal requirements of developing embryos. We recorded incubation behaviour of the New Zealand robin (Petroica longipes), a species with female‐only incubation, male incubation feeding and high nest predation rates. We examined how male incubation feeding, ambient temperature and food availability (invertebrate biomass) affected the different components of females’ incubation behaviour and whether incubation behaviour explained variation in nest survival. Our results suggest that male incubation feeding rates of 2.8 per hour affect the female’s incubation rhythm by reducing both on‐ and off‐bout duration, resulting in no effect on female nest attentiveness, thus no support for the female‐nutritional hypothesis. The incubation behaviours that we measured did not explain nest survival, despite high nest predation rates. Increased ambient temperature caused an increase in off‐bout duration, whereas increased food availability increased on‐bout duration. While males play a vital role in influencing incubation behaviour, female robins attempt to resolve the trade‐off between their own foraging needs and the thermal requirements of their developing embryos via alternating their incubation rhythm in relation to both food and temperature.
Home‐visit nurses' attitudes for providing effective assistance to clients with schizophrenia
Authors: Katakura Naoko , Yamamoto‐Mitani Noriko , Ishigaki Kazuko
Published: March 2010

There were two objectives of this study. The first was to identify the attitudes of home‐visit nurses towards clients with schizophrenia that lead to the provisions of effective care and positive client outcomes for clients with schizophrenia. The second was to develop a framework to understand how nurses acquire nursing attitudes that lead to such provisions. Seven expert home‐visit nurses who had successfully prevented rehospitalization of clients with schizophrenia for more than 2 years were interviewed. In the semistructured interviews, the nurses described their experiences in assisting one or two clients. Data were analyzed qualitatively. The central theme was having equal footing with the client. An effective nursing attitude was acquired through recognizing one's own preconceptions of clients with schizophrenia through two steps: encountering unexpected client behaviours and becoming aware of one's problematic care. For these clients, it was essential that the nurses reflect on their preconceptions towards clients with schizophrenia and alter these preconceptions by working with the clients and believing in their innate ability to live in the community. The findings suggest that the field of mental health home‐visit nursing might benefit from adding these educational components in order to cultivate effective nursing attitudes for assisting clients with schizophrenia.
Community mental health centres: A qualitative study of professionals' experiences
Authors: Elstad Toril Anne , Hellzén Ove
Published: March 2010

This article presents findings from a qualitative study of mental health work in community mental health centres with a multiprofessional workforce and aims of active user participation in the service. User participation implies collaborative relationships and different roles than that of expert professionals and dependent patients. How do professionals working in these services experience their work and professional role? This question was explored in order to highlight important aspects of community mental health work. A group of six experienced professionals from three community mental health centres in a Norwegian city were interviewed twice. The informants highlighted the complexity of community mental health work and the need to be flexible when working to support people with mental health problems in their everyday life situation. To see the service users as people and to facilitate social interaction was important. Their work was described as ‘liberating’ compared to working in institutions. However, although in their experience they found that professional knowledge and skills were important in their work situation, all had experienced that this was not always acknowledged by professionals in other services.
Coming out to talk about suicide: Gay men and suicidality
Authors: McAndrew Sue , Warne Tony
Published: March 2010

International studies report increased rates of mental health problems and subsequent suicidality among homosexual populations. While international health‐care policy is concerned with reducing suicide among young people, important research findings relating to gay people and suicidality remain unacknowledged in the Suicide Prevention Strategy for England. This qualitative study, utilizing single case studies, was used to gain an in‐depth understanding of the life experiences contributing to the suicidality of four gay men. The methodology was psychoanalytically informed, using free association narrative interviewing. The initial data analysis involved interpretation of each of the case studies and a subsequent analysis exploring the shared experiences found in each of the individual narratives. Thematically, these are described as ‘knowing and not knowing’, ‘the centrality of the father–son relationship’, ‘the loneliness of outsiderness’, ‘leading a double life’, and ‘crime and punishment’. The significance of the life experiences these themes illustrate reveal why some gay men might not only experience long‐term mental health problems, but also engage in suicidality. Individually and collectively, the analyses provide important insights for mental health nurses becoming more attuned to provide sensitive mental health care to those who have a gay sexual orientation.