bluuebunny/crossref_metadata_2025 huggingface dataset:
Comprehensive x-ray photoelectron spectroscopy study on compositional gradient lanthanum silicate film
Authors: Kakushima K. , Tachi K. , Song J. , Sato S. , Nohira H. , Ikenaga E. , Ahmet P. , Tsutsui K. , Sugii N. , Hattori T. , Iwai H.
Published: December 2009

Oxygen bonding in La-silicate film with compositional gradient has been characterized by x-ray photoelectron spectroscopy. Based on an analytical model of bridging and nonbridging oxygen, the O 1s spectra arising from La-silicate layer have been deconvoluted with compositionally dependent parameters. For a composition ratio of 1:1 for SiO2 and LaO1.5 on the surface of the La-silicate layer, negative binding energy shifts of 0.35 and 0.10 eV for bridging and nonbridging oxygen, respectively, have been found to well interpret the angle-resolved spectra. The method has also been applied to characterize the temperature dependence of interface reactions at La2O3/Si with in situ processed Pt electrode. SiO4 molecules combined with bridging and nonbridging oxygen atoms have been found to form by high temperature annealing. The thickness of the silicate layer of 0.4 nm at as-deposited state has been found grow up to 2.8 nm after 500 °C annealing. From rough estimation, it has been revealed that 10% of the newly created bridging oxygen atoms by annealing are incorporated into SiO4 network which contain also nonbridging oxygen atoms.
In situ monitoring the drying kinetics of knife coated polymer-fullerene films for organic solar cells
Authors: Schmidt-Hansberg B. , Klein M. F. G. , Peters K. , Buss F. , Pfeifer J. , Walheim S. , Colsmann A. , Lemmer U. , Scharfer P. , Schabel W.
Published: December 2009

The efficiency of polymer based bulk heterojunction (BHJ) solar cells mainly depends on the film morphology of the absorption layer and the interface properties between the stacked layers. A comparative study using atomic force microscopy (AFM) and optical in situ thin film drying measurements is performed. The strong impact of distinct drying scenarios on the polymer:fullerene BHJ layer morphology is investigated by AFM. The AFM images show a systematic dependency of structure sizes at the surface on drying kinetics. In addition thin film optical measurements for the determination of thin film drying kinetics and parameters are performed using a dedicated experimental setup. The data are used as the input for a quantitative simulation of the drying process. The film thickness decreases linearly during drying while the solvent mass fraction decreases moderately over a wide range until it drops rapidly. Subsequently the remaining solvent fraction evaporates considerably slower. Our work gives a fundamental understanding of the film formation kinetics and prerequisites for the systematic optimization of the film morphology in solution processed organic photovoltaic devices.
Optical models for ultrathin oxides on Si- and C-terminated faces of thermally oxidized SiC
Authors: Petrik Peter , Szilágyi Edit , Lohner Tivadar , Battistig Gabor , Fried Miklos , Dobrik Gergely , Biró László P.
Published: December 2009

The thickness, refractive index, density, and interface properties of thin thermal oxides on both Si- and C-terminated 4H-SiC faces were investigated by ellipsometry using optical models of increasing complexity. We used different parametrizations of the dielectric function, a transition layer, and also investigated the multisample approach. The thickness of the transition layer increases with decreasing oxide thickness below the layer thickness of about 30nm, it correlates with the surface roughness measured by atomic force microscopy, and it was found to be significantly larger for the C-terminated than that for the Si-terminated face. For oxide layer thicknesses larger than 30nm, the refractive index of the bulk oxide layer is the same as that of thermal SiO2 on Si. We found an apparent decrease in mass density (as well as optical density) with decreasing oxide thickness using a combination of ellipsometry and backscattering spectrometry, which can be explained by the surface roughness, depending on the layer thickness revealed by atomic force microscopy.
Advanced impurity trap memory with atomic-scale Ti impurities on LaAlO3: Evidence for the origins of enhanced memory performance
Authors: Jung Seungjae , Choi Hyejung , Ju Yongkyu , Chang Man , Jo Minseok , Lee Joonmyoung , Yoon Jaesik , Lee Choongman , Hwang Hyunsang
Published: December 2009

We investigated advanced impurity trap memory (ITM) with atomic-scale Ti impurities on LaAlO3. Our ITM showed excellent memory characteristics, including a memory window (MW) of 5 V under +12 V/−10 V, ∼44% retained charge in 10 yr retention at 85 °C, and endurance without MW degradation up to 104 cycles. To understand the origins of these enhanced characteristics, we conducted various physical analyses. Our results confirmed that the incorporation of ultrathin LaAlO3, featuring both thermodynamic stability for diffusion barrier of Ti and favorable energy band structure together with high dielectric constant for bandgap engineering of tunnel oxide, is responsible for enhanced performance.
Solvation and microscopic properties of ionic liquid/acetonitrile mixtures probed by high-pressure infrared spectroscopy
Authors: Umebayashi Yasuhiro , Jiang Jyh-Chiang , Lin Kuan-Hung , Shan Yu-Lun , Fujii Kenta , Seki Shiro , Ishiguro Shin-Ichi , Lin Sheng Hsien , Chang Hai-Chou
Published: December 2009

The microscopic features of binary mixtures formed by an ionic liquid (EMI+TFSA− or EMI+FSA−) and a molecular liquid (acetonitrile or methanol) have been investigated by high-pressure infrared spectroscopy. On the basis of its responses to changes in pressure and concentration, the imidazolium C–H appears to exist at least in two different forms, i.e., isolated and associated structures. The weak band at approximately 3102 cm−1 should be assigned to the isolated structure. CD3CN can be added to change the structural organization of ionic liquids. The compression of an EMI+TFSA−/CD3CN mixture leads to the increase in the isolated C–H band intensity. Nevertheless, the loss in intensity of the isolated structures was observed for EMI+FSA−/CD3CN mixtures as the pressure was elevated. In other words, the associated configuration is favored with increasing pressure by debiting the isolated form for EMI+FSA−/CD3CN mixtures. The stronger C–H⋯F interactions in EMI+FSA− may be one of the reasons for the remarkable differences in the pressure-dependent results of EMI+TFSA− and EMI+FSA−.
On the anisotropy of lattice polymers
Authors: Wang Qiang
Published: December 2009

We quantified the anisotropy of various lattice models used in polymer simulations based on two quantities: the Fourier transform of the normalized Boltzmann factor of allowable bonds on a lattice (which is the central quantity for describing lattice chain conformations) and the bulk lamellar period at the mean-field order-disorder transition (ODT) of symmetric diblock copolymers on a lattice (which is pertinent to the study of microphase separation). This allowed us to compare the anisotropy of different lattices and to design new lattice models that minimize the quantified anisotropy. A lattice field theory based on the same Hamiltonian used in the newly proposed fast lattice Monte Carlo simulations [Q. Wang, Soft Matter 5, 4564 (2009)] is also presented, along with some mean-field results on the ODT of symmetric diblock copolymers on these lattices obtained under the random-phase approximation.
A new experimental absolute nuclear magnetic shielding scale for oxygen based on the rotational hyperfine structure of H2O17
Authors: Puzzarini Cristina , Cazzoli Gabriele , Harding Michael E. , Vázquez Juana , Gauss Jürgen
Published: December 2009

The hyperfine structure in the rotational spectrum of water containing O17 has been investigated experimentally and by means of quantum-chemical calculations. The Lamb-dip technique has been used to resolve the hyperfine structure due to spin-rotation as well as spin-spin interactions and allowed the determination of the corresponding hyperfine parameters with high accuracy. The experimental investigation and, in particular, the analysis of the spectra have been supported by quantum-chemical computations at the coupled-cluster level. The experimental O17 isotropic spin-rotation constant of H2O17 has been used in a further step for the determination of the paramagnetic part of the corresponding nuclear magnetic shielding constant, whereas the diamagnetic contribution as well as vibrational and temperature corrections have been obtained from quantum-chemical calculations. This joint procedure leads to a value of 325.3(3) ppm for the oxygen shielding in H2O17 at 300 K, in good agreement with pure theoretical predictions, and in this way provides the basis for a new absolute oxygen shielding scale.
Predicted cooling powers for multilayer capacitors based on various electrocaloric and electrode materials
Authors: Kar-Narayan S. , Mathur N. D.
Published: December 2009

We argue that the multilayer capacitor (MLC) geometry is ideal for electrocaloric cooling. Thermal modeling predicts that a commercially available MLC, which serendipitously shows electrocaloric effects, could constitute the heart of an idealized heat pump delivering a continuous cooling power of 22.5 W kg−1. This figure could be increased via materials optimization to ∼2875 W kg−1, such that an MLC array whose sheet area is just ∼0.56 m2 would deliver the ∼20 kW cooling power of typical air-cooled chillers for air-conditioning at residential and commercial sites. Expensive materials are not required, and performance could be further enhanced via geometrical improvements.
Molecular structure and carrier distributions at semiconductor/dielectric interfaces in organic field-effect transistors studied with sum frequency generation microscopy
Authors: Nakai Ikuyo F. , Tachioka Masaaki , Ugawa Akito , Ueda Tadashi , Watanabe Kazuya , Matsumoto Yoshiyasu
Published: December 2009

Infrared-visible sum frequency generation (SFG) microscopy was applied to the observation of semiconductor/dielectric interfaces in organic field-effect transistors fabricated with pentacene films and polyvinyl phenol dielectric layers. SFG intensity at the interface was greatly increased by carrier injection. The large enhancement in SFG intensity enables us to observe clearly the vibrational spectra of molecules and the spatial distributions of charge density at the interface.
Copper adsorption on humic acid coated gibbsite: comparison with single sorbent systems
Authors: Antelo Juan , Fiol Sarah , Mariño Silvia , Arce Florencio , Gondar Dora , Lopez Rocio
Published: December 2009

Environmental context. Adsorption processes control the mobility and bioavailability of nutrients and contaminants in soils, sediments and aquatic systems. Natural organic matter and aluminium oxides are important reactive materials present in natural systems and their mutual interaction may alter the surface properties of both materials, playing an important role on the fate of different contaminants, such as copper, in the environment. The present study illustrates the importance of these interactions, showing that the presence of natural organic matter has a synergic effect on the copper adsorption on the aluminium oxide surface.
Abstract. Copper adsorption processes on aluminium oxides may significantly control the mobility and transport of copper ions in soils and surface waters. The binding of protons and copper to humic acid (HA) and to gibbsite as single sorbent systems was investigated and the results then used to test the validity of the Linear Additivity Model (LAM) for describing copper binding to gibbsite/HA systems. More copper was adsorbed in the gibbsite/HA/Cu2+ ternary system, at pH 4 and 6 and ionic strength 0.1 M, than in the corresponding binary systems. Although copper adsorption on gibbsite at pH 4 is rather small, the enhancement in sorption was noteworthy, and can be attributed to the formation of ternary complexes and changes in the electrostatic potentials at the mineral surface or at the HA as a result of their mutual interaction. The LAM predicted satisfactorily the experimental results at pH 6, whereas it underestimated the copper binding at pH 4.
Postfrontal nanoparticles at Cape Grim: observations
Authors: Gras John L. , Jimi Salah I. , Siems Steven T. , Krummel Paul B.
Published: December 2009

Environmental context. Clouds and the factors controlling cloud properties are essential components in understanding and accurately predicting global climate change. This work examines nanometre-sized atmospheric particles, particularly bursts of enhanced particle concentrations following cold fronts over the Southern Ocean. The properties of these events have been established to enable modelling of their significance as a source of cloud-droplet-forming nuclei.
Abstract. Nanoparticles (diameter <10 nm) were studied in clean maritime air at Cape Grim over a 2-year period. Concentrations were determined using a condensation nucleus counter (CNC) and an ultra-CNC (UCNC), requiring careful treatment of drifts in counter efficiency. This is the first extended examination of nanoparticles following cold fronts and shows that nanoparticle enhancements were present following 94% of 121 cold fronts studied. Typical enhancements were ~100 cm–3 with maxima ~300–500 cm–3, occur 9–11 h after the front and contain multiple peaks with peak-to-peak separation of 8–11 h. Most enhancements were associated with drier conditions, indicative of increased entrainment of free-tropospheric air after the front. The quasi-periodicity of the enhancements may be related to mesoscale structures in cloud fields following fronts but this requires testing. This quantification of event properties allows evaluation of the significance of these events for the cloud nucleating particle (CCN) population.
Application of chemometric analysis for identifying pollution sources: a case study on the River Adyar, India
Authors: Venugopal T. , Giridharan L. , Jayaprakash M.
Published: December 2009

The various factors responsible for the chemical budget and pollution of river water have been evaluated and characterised using various statistical tools. The potential sources of pollution that alter the chemical composition of River Adyar water have been identified and quantified. Thirty-three samples were collected from the River Adyar and basic chemical parameters and heavy metals were interpreted by the systematic application of statistical techniques. The relationships among the various ions were examined and the sources of origin were evaluated using correlation studies. An R-mode factor analysis revealed that the chemistry of the river water largely depends on anthropogenic activities, rock–water interaction and saline water intrusion. A cluster analysis was applied and the major and minor clusters for pre-monsoon and post-monsoon seasons were classified. This classification was found to be in line with the results of the R-mode factor analysis. Seasonal variation in the chemistry and pollution level of the river water was clearly indicated by both cluster and factor analyses. Factor scores, which give vital information on the variation of the factors by station, were successfully applied. The contributing factors and any seasonal effect on the stations were evaluated and interpreted.
Optimising extraction of extracellular polymeric substances (EPS) from benthic diatoms: comparison of the efficiency of six EPS extraction methods
Authors: Takahashi Eri , Ledauphin Jérôme , Goux Didier , Orvain Francis
Published: December 2009

There is no universal method that can be applied to extract bound extracellular polymeric substances (EPS) from benthic diatoms of intertidal sediments without causing cell lysis. Six extraction methods were tested on a diatom culture of Navicula jeffreyi to establish the best compromise between high yields of carbohydrate extraction and minimum cell lysis. Extraction with distilled water provoked cell lysis (as already known). The five other extraction methods (dowex resin, artificial seawater of half salinity and extractions after pretreatment with gluteraldehyde by three methods: water, dowex water and dowex buffer) did not provoke cell lysis as shown by transmission electronic microscopy. This result was confirmed by the minimum release of internal compounds (protein, ATP) and by the low proportions of glucose in dowex-extracted EPS compared with the water-extracted EPS, from which the high glucose content must be inferred as contamination by the chrysolaminaran. The extraction with dowex resin resulted in the second-highest concentration of carbohydrate after the water extraction and the EPS were especially rich in deoxy sugars, hence increasing the hydrophobic feature of these substances. For these reasons, we recommend extraction with dowex, which is also the best method for extracting bound EPS from other biofilms such as in activated sludges.
Assemblages of reef fish settling on artificial substrates: effect of ambient habitat over two temporal scales
Authors: Mellin C. , Ponton D.
Published: December 2009

Artificial habitats provide a unique opportunity to investigate how habitat characteristics structure juvenile fish assemblages after settlement. We quantified the differences between assemblages of juvenile fish on artificial substrates moored in macroalgal beds, seagrass beds or coral patches over two temporal scales that corresponded to a short (48 h) and a longer (>2 weeks) immersion time, respectively. The highest abundances were obtained from artificial habitats moored in seagrass beds, whatever the immersion time was. Total abundances of juveniles increased 3-fold between a short and a long immersion, suggesting a net accumulation of individuals with time. Moreover, significant differences in juvenile fish assemblage structure were observed between habitats and between immersion times. Artificial habitats may reflect species-specific habitat preferences at settlement at a meso-scale; however, caution must be paid to the effects of ambient habitat and post-settlement processes on juvenile fish assemblages observed on artificial habitats.
Effects of acid rainfall on juvenile Atlantic salmon (Salmo salar) antipredator behaviour: loss of chemical alarm function and potential survival consequences during predation
Authors: Leduc Antoine O. H. C. , Roh Ellie , Brown Grant E.
Published: December 2009

Many organisms rely on chemosensory cues to mediate predation risks. Recent studies have demonstrated impaired chemosensory detection ability under weak acidification. Because rainfall may lead to episodic acidification of surface water, we assessed the effects of acid rain on chemosensory alarm functions. Under natural conditions, we quantified alarm behaviour of juvenile Atlantic salmon (Salmo salar) exposed to conspecific chemical alarm cues before and following rainfall. Before rainfall, salmon were capable of an alarm response in the study streams. After rainfall, salmon from Devil’s Brook did not respond to the alarm cues whereas the detection of salmon from Catamaran Brook (a comparable stream having higher acid neutralising capacity) was maintained. To relate these findings to predator–prey encounters, we performed a second experiment where we staged encounters between prey (rainbow trout, Oncorhynchus mykiss) and predator (largemouth bass, Micropterus salmoides) exposed to acidified and unacidified rainbow trout chemical alarm cues. Trout exposed to acidified alarm cues survived for a significantly shorter amount of time than trout exposed to unacidified alarm cues, whereas no difference in overall predator behaviour was observed. Our results suggest that episodic acidification in small nursery streams may disrupt the chemical information mediated by the chemical alarm cues that can translate into higher survival costs for prey.
Characterization of an electron conduit between bacteria and the extracellular environment
Authors: Hartshorne Robert S. , Reardon Catherine L. , Ross Daniel , Nuester Jochen , Clarke Thomas A. , Gates Andrew J. , Mills Paul C. , Fredrickson Jim K. , Zachara John M. , Shi Liang , Beliaev Alex S. , Marshall Matthew J. , Tien Ming , Brantley Susan , Butt Julea N. , Richardson David J.
Published: December 2009

A number of species of Gram-negative bacteria can use insoluble minerals of Fe(III) and Mn(IV) as extracellular respiratory electron acceptors. In some species of
Shewanella
,
deca
-heme electron transfer proteins lie at the extracellular face of the outer membrane (OM), where they can interact with insoluble substrates. To reduce extracellular substrates, these redox proteins must be charged by the inner membrane/periplasmic electron transfer system. Here, we present a spectro-potentiometric characterization of a trans-OM
icosa
-heme complex, MtrCAB, and demonstrate its capacity to move electrons across a lipid bilayer after incorporation into proteoliposomes. We also show that a stable MtrAB subcomplex can assemble in the absence of MtrC; an MtrBC subcomplex is not assembled in the absence of MtrA; and MtrA is only associated to the membrane in cells when MtrB is present. We propose a model for the modular organization of the MtrCAB complex in which MtrC is an extracellular element that mediates electron transfer to extracellular substrates and MtrB is a trans-OM spanning β-barrel protein that serves as a sheath, within which MtrA and MtrC exchange electrons. We have identified the MtrAB module in a range of bacterial phyla, suggesting that it is widely used in electron exchange with the extracellular environment.
β-arrestin- but not G protein-mediated signaling by the “decoy” receptor CXCR7
Authors: Rajagopal Sudarshan , Kim Jihee , Ahn Seungkirl , Craig Stewart , Lam Christopher M. , Gerard Norma P. , Gerard Craig , Lefkowitz Robert J.
Published: December 2009

Ubiquitously expressed seven-transmembrane receptors (7TMRs) classically signal through heterotrimeric G proteins and are commonly referred to as G protein-coupled receptors. It is now recognized that 7TMRs also signal through β-arrestins, which act as versatile adapters controlling receptor signaling, desensitization, and trafficking. Most endogenous receptors appear to signal in a balanced fashion using both β-arrestin and G protein-mediated pathways. Some 7TMRs are thought to be nonsignaling “decoys” because of their inability to activate typical G protein signaling pathways; it has been proposed that these receptors act to scavenge ligands or function as coreceptors. Here we demonstrate that ligand binding to the decoy receptor CXCR7 does not result in activation of signaling pathways typical of G proteins but does activate MAP kinases through β-arrestins in transiently transfected cells. Furthermore, we observe that vascular smooth muscle cells that endogenously express CXCR7 migrate to its ligand interferon-inducible T-cell alpha chemoattractant (ITAC), an effect that is significantly attenuated by treatment with either a CXCR7 antagonist or β-arrestin depletion by siRNA. This example of an endogenous “β-arrestin-biased” 7TMR that signals through β-arrestin in the absence of G protein activation demonstrates that some 7TMRs encoded in the genome have evolved to signal through β-arrestin exclusively and suggests that other receptors that are currently thought to be orphans or decoys may also signal through such nonclassical pathways.
Examining HIV, drug use and risk behaviours: A case study in the custodial settings of Thailand and Indonesia
Authors: Thomson Nicholas , Reid Gary , Dolan Kate
Published: December 2009

Custodial settings are high‐risk environments for HIV. This paper examines publicly available data about the drug use and risk behaviours of Thai and Indonesian prisoners and outlines a process used to collect new data. In 2005, the Departments of Corrections in Thailand and Indonesia requested researchers examine HIV and drug use issues but the findings are too sensitive to publish. The Departments of Corrections in Thailand and Indonesia are using the results to develop public health
responses.
‘Traumatisers or traumatised’: Trauma experiences and personality characteristics of Australian prisoners
Authors: Egeressy Anna , Butler Tony , Hunter Mick
Published: December 2009

Background: Post‐traumatic stress disorder (PTSD) is over represented in the prisoner population and is predictive of violence and suicide. This raises issues in relation to prisoner management, as well as theoretical issues such as why there is a range of vulnerability for PTSD. The current study examines the relationship between PTSD and personality profiles of prisoners. Method: Data from 1305 participants in the NSW survey of health in prisoners are examined to identify relationships between personality profiles derived from the Temperament and Character Inventory (TCI) and PTSD. Participants are grouped as experiencing no trauma; with a trauma history but no PTSD; and being diagnosed with PTSD. A logistic regression modelled significant predictors of PTSD. These data indicated that women prisoners report PTSD at twice the rate of males. An increased risk for PTSD is associated with high Harm Avoidance, low Self‐Directedness, high Persistence and high Self‐Transcendence. Conclusions: A combination of both temperament and character traits influences the trajectory towards PTSD development. Targeted treatment of these traits is needed in addressing the problems of prisoners with PTSD and managing the associated risks of violence and suicide.
‘Coming together to share, listen and learn’: A conference with a vision
Authors: Smith Martin Megan , Elwood Martin Ruth
Published: December 2009

The inaugural collaborative Canadian Prison‐Academic‐Community Health and Education was organized by the Collaborating Centre for Prison Health and Education and supported by the University of British Columbia (UBC), Nicola Valley Institute of Technology (NVIT) and Simon Fraser University (SFU) on 4th and 5th December 2008. The conference objective was to encourage and facilitate collaborative opportunities for enhancing health, education, research, service and advocacy, for the social well‐being and (re)integration of individuals in custody, their families and communities. Four conference goals were articulated: (1) To share promising practices, current evidence and scholarship in health and education related to prison populations. (2) To bring together prison, academic and community members to create collaborative opportunities for partnerships and reciprocal learning. (3) To discuss and develop policy initiatives to promote positive change within prison health and education.
(4) To explore the mental, physical, emotional and spiritual aspects of prisoner health and education.
FoldAmyloid: a method of prediction of amyloidogenic regions from protein sequence
Authors: Garbuzynskiy Sergiy O. , Lobanov Michail Yu. , Galzitskaya Oxana V.
Published: December 2009

Motivation: Amyloidogenic regions in polypeptide chains are very important because such regions are responsible for amyloid formation and aggregation. It is useful to be able to predict positions of amyloidogenic regions in protein chains.

Results: Two characteristics (expected probability of hydrogen bonds formation and expected packing density of residues) have been introduced by us to detect amyloidogenic regions in a protein sequence. We demonstrate that regions with high expected probability of the formation of backbone–backbone hydrogen bonds as well as regions with high expected packing density are mostly responsible for the formation of amyloid fibrils. Our method (FoldAmyloid) has been tested on a dataset of 407 peptides (144 amyloidogenic and 263 non-amyloidogenic peptides) and has shown good performance in predicting a peptide status: amyloidogenic or non-amyloidogenic. The prediction based on the expected packing density classified correctly 75% of amyloidogenic peptides and 74% of non-amyloidogenic ones. Two variants (averaging by donors and by acceptors) of prediction based on the probability of formation of backbone–backbone hydrogen bonds gave a comparable efficiency. With a hybrid-scale constructed by merging the above three scales, our method is correct for 80% of amyloidogenic peptides and for 72% of non-amyloidogenic ones. Prediction of amyloidogenic regions in proteins where positions of amyloidogenic regions are known from experimental data has also been done. In the proteins, our method correctly finds 10 out of 11 amyloidogenic regions.

Availability: The FoldAmyloid server is available at http://antares.protres.ru/fold-amyloid/

Contact:  ogalzit@vega.protres.ru
Impact of gender on benefits of exercise training on sympathetic nerve activity and muscle blood flow in heart failure
Authors: Antunes‐Correa Ligia M. , Melo Ruth C. , Nobre Thais S. , Ueno Linda M. , Franco Fabio G.M. , Braga Ana M.W. , Rondon Maria U.P.B. , Brum Patricia C. , Barretto Antonio C.P. , Middlekauff Holly R. , Negrao Carlos E.
Published: December 2009

Aims

We compared the effects of exercise training on neurovascular control and functional capacity in men and women with chronic heart failure (HF).

Methods and results

Forty consecutive HF outpatients from the Heart Institute, University of Sao Paulo, Brazil were divided into the following four groups matched by age: men exercise‐trained (n = 12), men untrained (n = 10), women exercise‐trained (n = 9), women untrained (n = 9). Maximal exercise capacity was determined from a maximal progressive exercise test on a cycle ergometer. Forearm blood flow was measured by venous occlusion plethysmography. Muscle sympathetic nerve activity (MSNA) was recorded directly using the technique of microneurography. There were no differences between groups in any baseline parameters. Exercise training produced a similar reduction in resting MSNA (P = 0.000002) and forearm vascular resistance (P = 0.0003), in men and women with HF. Peak VO2 was similarly increased in men and women with HF (P = 0.0003) and VE/VCO2 slope was significantly decreased in men and women with HF (P = 0.0007). There were no significant changes in left‐ventricular ejection fraction in men and women with HF.

Conclusion

The benefits of exercise training on neurovascular control and functional capacity in patients with HF are independent of gender.
Acute kidney injury and outcomes in acute decompensated heart failure: evaluation of the RIFLE criteria in an acutely ill heart failure population
Authors: Hata Noritake , Yokoyama Shinya , Shinada Takuro , Kobayashi Nobuaki , Shirakabe Akihiro , Tomita Kazunori , Kitamura Mitsunobu , Kurihara Osamu , Takahashi Yasuhiro
Published: December 2009

Aims

The clinical course including the outcome of acute decompensated heart failure (ADHF) correlates with renal dysfunction, but the evaluation of renal function has not yet been standardized. We therefore investigated the relationship between the prognosis of ADHF and acute kidney injury (AKI) evaluated using the risk, injury, failure, loss, end stage (RIFLE) criteria.

Methods and results

This study assessed 376 consecutive patients with ADHF admitted to the intensive care unit (ICU) (mean age 71.6 years; 238 male). The underlying aetiology was ischaemic heart disease, hypertensive heart disease, cardiomyopathy, valvular diseases, and ‘other’ in 124, 70, 60, 107, and 15 patients, respectively. We defined AKI according to the RIFLE criteria, and the most severe RIFLE classifications during hospitalization were adopted to assess patient outcomes. The in‐hospital mortality was significantly higher among patients with AKI (29 of 275; 10.5%) than in those without AKI (1 of 101; 1.0%, P = 0.0010). Both ICU and hospital stays were longer for patients with AKI (8.8 ± 15.4 vs. 48.6 ± 47.6 days), than for patients without (5.0 ± 2.8 vs. 25.7 ± 16.8 days, P < 0.05 and P < 0.001).

Conclusion

Acute kidney injury evaluated by the RIFLE criteria was associated with a poorer outcome for patients with ADHF.
An economic evaluation of rosuvastatin treatment in systolic heart failure: evidence from the CORONA trial
Authors: Lorgelly Paula K. , Briggs Andrew H. , Wedel Hans , Dunselman Peter , Hjalmarson Åke , Kjekshus John , Waagstein Finn , Wikstrand John , Jánosi András , van Veldhuisen Dirk J. , Barrios Vivencio , Fonseca Cândida , McMurray John J.V. ,   on behalf of the CORONA Study Group
Published: December 2009

Aims

To estimate the cost‐effectiveness of 10 mg rosuvastatin daily for older patients with systolic heart failure in the Controlled Rosuvastatin Multinational Study in Heart Failure (CORONA) trial.

Methods and results

This within trial analysis of CORONA used major cardiovascular (CV) events as the outcome measure. Resource use was valued and the costs of hospitalizations, procedures, and statin use compared. Cost‐effectiveness was estimated as cost per major CV event avoided. There were significantly fewer major CV events in the rosuvastatin group compared with the placebo group (1.04 vs. 1.20 per patient; difference 0.164; 95% CI: 0.075–0.254, P < 0.001). The average cost of CV hospitalizations and procedures was significantly lower for those receiving rosuvastatin (£1531 vs. £1769; difference £238; 95% CI: £73–403, P = 0.005); the additional cost of the statin resulted in significantly higher total costs for the rosuvastatin group (£1769 vs. £2072; difference £303; 95% CI: £138–468, P < 0.001). Overall, rosuvastatin was found to cost £1840 (95% CI: £562–6028) per major CV event avoided.

Conclusion

This economic analysis showed that a significant reduction in major CV events with rosuvastatin led to significantly reduced costs of CV hospitalizations and procedures. The reduction in associated costs for major CV events was found to offset partially (by 44%) the cost of rosuvastatin treatment in patients with systolic heart failure.
Differential prognostic effect of systolic blood pressure on mortality according to left‐ventricular function in patients with acute heart failure
Authors: Núñez Julio , Núñez Eduardo , Fonarow Gregg C. , Sanchis Juan , Bodí Vicent , Bertomeu‐González Vicente , Miñana Gema , Merlos Pilar , Bertomeu‐Martínez Vicente , Redón Josep , Chorro Francisco J. , Llàcer Angel
Published: December 2009

Aims

To evaluate the relationship between systolic blood pressure (SBP) and long‐term mortality in patients with acute heart failure (AHF) stratified by ejection fraction (LVEF): reduced (≤40%) vs. preserved (≥50%).

Methods and results

We studied 1049 consecutive patients admitted with AHF. Systolic blood pressure was determined in the emergency department. Left‐ventricular ejection fraction was categorized as ≤40% (n = 288), 41–49% (n = 174), or ≥50% (n = 587). Cox regression analysis was used for multivariable analysis. Mean age and SBP were 73 ± 11 years and 150 ± 36 mmHg, respectively. During a median follow‐up of 18 months, 290 deaths (33.1%) were identified. Higher SBP was associated with lower mortality. In multivariable analysis, a differential effect of SBP across LVEF status was documented (P‐value for interaction = 0.036). In linear models, SBP was shown to be inversely related with mortality in both groups (per 10 mmHg decrease): HR(LVEF ≥ 50%): 1.06, CI 95% = 1.01–1.11; P = 0.016, and HR(LVEF ≤ 40%): 1.16, 95% CI = 1.08–1.25; P < 0.001). When SBP was modelled with restrictive cubic splines, an inverse and almost linear relationship with mortality was shown in patients with LVEF ≤40% (P < 0.001), whereas in patients with LVEF ≥50%, SBP followed a J‐shape curve.

Conclusion

In patients with AHF, SBP showed a differential prognostic effect on mortality according to LVEF status; when LVEF was ≤40%, SBP was linearly and inversely associated with mortality. Conversely, in patients with LVEF ≥50% this relationship showed a J‐shape pattern.
Sources of bycatch of loggerhead sea turtles in the western Mediterranean other than drifting longlines
Authors: Álvarez de Quevedo Irene , Cardona Luis , De Haro Andrea , Pubill Eva , Aguilar Alex
Published: December 2009

Álvarez de Quevedo, I., Cardona, L., De Haro, A., Pubill, E., and Aguilar, A. 2010. Sources of bycatch of loggerhead sea turtles in the western Mediterranean other than drifting longlines. – ICES Journal of Marine Science, 67: 677–685. A survey, including questionnaires to fishers and observers on board fishing vessels, was conducted to assess turtle bycatch in the waters off Catalonia (northeastern Spain), a region inhabited mainly by loggerhead sea turtles (Caretta caretta) from the highly endangered eastern Mediterranean rookeries. Observer reports confirmed that the data produced by the interviewees were reliable, so interview results were used to estimate turtle bycatch. The number of turtles caught monthly per vessel was estimated at 0.01 for bottom longlines, 0.02 for trammelnets, 0.07 for bottom trawling, and 1.2 for drifting longlines. From these values, 481 (95% CI: 472–491) turtles were estimated to be taken annually as bycatch by the whole fleet. Bottom trawling and trammelnets were the most widely used fishing gears (33 and 31% of the total 11 237 fishing months), but most turtles were caught either by bottom trawlers (249; 95% CI 83–415) or by drifting longlines (124; 95% CI: 40–199). Ivlev's electivity index revealed that bottom trawler bycatch was higher than expected in areas with a wide continental shelf. Given the heavy turtle mortality associated with bottom trawling and the fact that, in southern Catalonia, the fleet mainly takes turtles from western Mediterranean rookeries, it is suggested that the fishery be regulated through winter fishing restrictions, reducing the number of bottom trawlers working in the area, reducing the time the net is in the water to prevent turtle suffocation, or being obliged to use turtle excluder devices.
Genome-wide analysis of DNA repeats in Burkholderia cenocepacia J2315 identifies a novel adhesin-like gene unique to epidemic-associated strains of the ET-12 lineage
Authors: Mil-Homens Dalila , Rocha Eduardo P. C. , Fialho Arsenio M.
Published: December 2009

Members of the Burkholderia cepacia complex (Bcc) are respiratory pathogens in patients with cystic fibrosis (CF). Close repetitive DNA sequences often associate with surface antigens to promote genetic variability in pathogenic bacteria. The genome of Burkholderia cenocepacia J2315, a CF isolate belonging to the epidemic lineage Edinburgh–Toronto (ET-12), was analysed for the presence of close repetitive DNA sequences. Among the 422 DNA close repeats, 45 genes potentially involved in virulence were identified and grouped into 12 classes; of these, 13 genes were included in the antigens class. Two trimeric autotransporter adhesins (TAA) among the 13 putative antigens are absent from the other Burkholderia genomes and are clustered downstream of the cci island that is a marker for transmissible B. cenocepacia strains. This cluster contains four adhesins, one outer-membrane protein, one sensor histidine kinase and two transcriptional regulators. By using PCR, we analysed three genes among 47 Bcc isolates to determine whether the cluster was conserved. These three genes were present in the isolates of the ET-12 lineage but absent in all the other members. Furthermore, the BCAM0224 gene was exclusively detected in this epidemic lineage and may serve as a valuable new addition to the field of Bcc diagnostics. The BCAM0224 gene encodes a putative TAA that demonstrates adhesive properties to the extracellular matrix protein collagen type I. Quantitative real-time PCR analysis indicated that BCAM0224 gene expression occurred preferentially for cells grown under high osmolarity, oxygen-limited conditions and oxidative stress. Inactivation of BCAM0224 in B. cenocepacia attenuates the ability of the mutant to promote cell adherence in vitro and impairs the overall bacterial virulence against Galleria mellonella as a model of infection. Together, our data show that BCAM0224 from B. cenocepacia J2315 represents a new collagen-binding TAA with no bacterial orthologues which has an important role in cellular adhesion and virulence.
Candida albicans sphingolipid C9-methyltransferase is involved in hyphal elongation
Authors: Oura Takahiro , Kajiwara Susumu
Published: December 2009

C9-methylated glucosylceramide is a fungus-specific sphingolipid. This lipid is a major membrane component in the cell and is thought to play important roles in the growth and virulence of several fungal species. To investigate the importance of the methyl branch of the long-chain base in glucosylceramides in pathogenic fungi, we identified and characterized a sphingolipid C9-methyltransferase gene (MTS1, C9-MethylTransferase forSphingolipid1) in the pathogenic yeastCandida albicans. Themts1disruptant lacked (E,E)-9-methylsphinga-4,8-dienine in its glucosylceramides and contained (E)-sphing-4-enine and (E,E)-sphinga-4,8-dienine. Reintroducing theMTS1gene into themts1disruptant restored the synthesis of (E,E)-9-methylsphinga-4,8-dienine in the glucosylceramides. We also created a disruptant of theHSX11gene, encoding glucosylceramide synthase, which catalyses the final step of glucosylceramide synthesis, inC. albicansand compared this mutant with themts1disruptant. TheC. albicans mts1andhsx11disruptants both had a decreased hyphal growth rate compared to the wild-type strain. Thehsx11disruptant showed increased susceptibility to SDS and fluconazole, similar to a previously reportedsld1disruptant that contained only (E)-sphing-4-enine in its glucosylceramides, suggesting that these strains have defects in their cell membrane structures. In contrast, themts1disruptant grew similarly to wild-type in medium containing SDS or fluconazole. These results suggest that the C9-methyl group of a long-chain base in glucosylceramides plays an important role in the hyphal elongation ofC. albicansindependent of lipid membrane disruption.
Mitochondrial processing peptidase activity is controlled by the processing of α-MPP during development in Dictyostelium discoideum
Authors: Nagayama Koki , Ohmachi Tetsuo
Published: December 2009

We investigated the expression of theαsubunit of theDictyosteliummitochondrial processing peptidase (Ddα-MPP) during development. Ddα-MPP mRNA is expressed at the highest levels in vegetatively growing cells and during early development, and is markedly downregulated after 10 h of development. The Ddα-MPP protein is expressed as two forms, designatedα-MPPHandα-MPPL, throughout theDictyosteliumlife cycle. The larger form,α-MPPH, is cleaved to produce the functionalα-MPPLform. We were not able to isolate mutants in which theα-mppgene had been disrupted. Instead, an antisense transformant,αA2, expressingα-MPP at a lower level than the wild-type AX-3 was isolated to examine the function of theα-MPP protein. Development of theαA2 strain was normal until the slug formation stage, but the slug stage was prolonged to ∼24 h. In this prolonged slug stage, onlyα-MPPHwas present, andα-MPPLprotein and MPP activity were not detected. After 28 h,α-MPPLand MPP activity reappeared, and normal fruiting bodies were formed after a delay of approximately 8 h compared with normal development. These results indicate that MPP activity is controlled by the processing ofα-MPPHtoα-MPPLduring development inDictyostelium.
Gα5 subunit-mediated signalling requires a D-motif and the MAPK ERK1 in Dictyostelium
Authors: Raisley Brent , Nguyen Hoai-Nghia , Hadwiger Jeffrey A.
Published: December 2009

TheDictyosteliumGα5 subunit has been shown to reduce cell viability, inhibit folate chemotaxis and accelerate tip morphogenesis and gene expression during multicellular development. Alteration of the D-motif (mitogen-activated protein kinase docking site) at the amino terminus of the Gα5 subunit or the loss of extracellular signal-regulated kinase (ERK)1 diminished the lethality associated with the overexpression or constitutive activation of the Gα5 subunit. The amino-terminal D-motif of the Gα5 subunit was also found to be necessary for the reduced cell size, small aggregate formation and precocious developmental gene expression associated with Gα5 subunit overexpression. This D-motif also contributed to the aggregation delay in cells expressing a constitutively active Gα5 subunit, but the D-motif was not necessary for the inhibition of folate chemotaxis. These results suggest that the amino-terminal D-motif is required for some but not all phenotypes associated with elevated Gα5 subunit functions during growth and development and that ERK1 can function in Gα5 subunit-mediated signal transduction.
A SNP discovery method to assess variant allele probability from next-generation resequencing data
Authors: Shen Yufeng , Wan Zhengzheng , Coarfa Cristian , Drabek Rafal , Chen Lei , Ostrowski Elizabeth A. , Liu Yue , Weinstock George M. , Wheeler David A. , Gibbs Richard A. , Yu Fuli
Published: December 2009

Accurate identification of genetic variants from next-generation sequencing (NGS) data is essential for immediate large-scale genomic endeavors such as the 1000 Genomes Project, and is crucial for further genetic analysis based on the discoveries. The key challenge in single nucleotide polymorphism (SNP) discovery is to distinguish true individual variants (occurring at a low frequency) from sequencing errors (often occurring at frequencies orders of magnitude higher). Therefore, knowledge of the error probabilities of base calls is essential. We have developed Atlas-SNP2, a computational tool that detects and accounts for systematic sequencing errors caused by context-related variables in a logistic regression model learned from training data sets. Subsequently, it estimates the posterior error probability for each substitution through a Bayesian formula that integrates prior knowledge of the overall sequencing error probability and the estimated SNP rate with the results from the logistic regression model for the given substitutions. The estimated posterior SNP probability can be used to distinguish true SNPs from sequencing errors. Validation results show that Atlas-SNP2 achieves a false-positive rate of lower than 10%, with an ∼5% or lower false-negative rate.
Increased mortality and morbidity in mild primary hyperparathyroid patients. The Parathyroid Epidemiology and Audit Research Study (PEARS)
Authors: Yu Ning , Donnan Peter T. , Flynn Robert W. V. , Murphy Michael J. , Smith David , Rudman Andrew , Leese Graham P.
Published: December 2009

Objective  To describe mortality and disease‐specific morbidities in patients with mild primary hyperparathyroidism (PHPT).

Design  Retrospective population‐based observational study.

Setting  Tayside, Scotland, from 1997 to 2006.

Participants  Patients with mild PHPT were selected from a predefined PHPT cohort between 1997 and 2006.

Main outcome measures  Standardised mortality ratios (SMRs) were examined for all‐cause mortality, as well as cardiovascular and cancer mortality. Standardised morbidity ratios and standardised incidence ratios were also calculated for eleven observed co‐morbidities.

Results  In total, there were 1683 (69·1% female) patients identified with mild PHPT in Tayside. Patients were found to have an increased risk of all‐cause mortality and cardiovascular mortality (SMR‐all cause 2·62, 95% CI 2·39–2·86; SMR‐cardiovascular 2·68, 95% CI 2·34–3·05). Patients with mild PHPT had a significantly increased risk of developing cardiovascular and cerebrovascular disease, renal dysfunction and fractures compared to the age‐ and sex‐adjusted general population.

Conclusions  Mortality and morbidity were increased for patients with mild untreated PHPT, which is similar to more severe PHPT.