bluuebunny/crossref_metadata_2025 huggingface dataset:
Difference and variation of the sef14 operon gene clusters in S. pullorum
Authors: Zhu C. H. , Wu J. , Chen W. W. , Hassan H. Musa , Zhu G. Q.
Published: August 2010

SEF14 fimbriae are only found in some strains of serogroup‐D Salmonella such as S. enteritidis, suggesting that SEF14 fimbriae may affect serovar‐specific virulence traits. In this study, we found that prevalence of sefA, sefD and sefR genes in S. dublin and S. enteritidis was 100%. In 18 isolates of S. pullorum, the prevalence of sefA gene was 100%, while the prevalence of sefD and sefR genes was 38.9% (7/18), and 11 strains isolated after 1980s did not contain any gene sefD or sefR. Interestingly, among the 7 strains of S. pullorum before 1980s, the sefD sequence has a missing base pair at position 196 and caused open reading frame (ORF) shift, resulting in a stop codon (TAG) at position 71 amino acid residual (Leu of TTA at position 214–216 shift into stop codon of TAG at position 215–217). Unlike S. pullorum, all S. enteritidis and S. dublin tested could express SEF14 fimbriae in vitro. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth temperature associated protein expression and membrane fatty acid composition profiles of Salmonella enterica serovar Typhimurium
Authors: Balamurugan Sampathkumar
Published: August 2010

Total cellular proteins and fatty acid composition profiles of mid‐log phase cells of Salmonella enterica serovar Typhimurium grown at 8, 25, 37 or 42 °C were separated by 2D‐PAGE and FAME analysis. Growth temperature associated protein expression can be grouped into 3 thermal classes which include proteins whose expression is: I) optimal at 37 °C, meaning their expression peaked at 37 °C; II) up‐regulated with an increase in growth temperature; III) down‐regulated with increase in growth temperature; meaning their expression peaked at 8 °C. At higher growth temperatures, proteins belonging to the functional groups of amino acid transport and metabolism, nucleotide metabolism, energy metabolism and post‐translation modifications (chaperones) are present in substantially higher amounts. This increase in abundance is regulated in a temperature dependent manner. It is important to point out that proteins involved in energy metabolism observed in higher amounts at higher growth temperatures all belong to the glycolysis pathway, while at 8 °C they belonged to the TCA cycle. Increase in growth temperatures results in a decrease in membrane fatty acid unsaturation and an increase in saturated and cyclic fatty acids. These results provide an insight into the dynamic molecular and physiological responses of Salmonella Typhimurium during growth at different temperatures. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Purification of a toxic cysteine protease produced by pathogenic Aeromonas hydrophila isolated from rainbow trout
Authors: Liu Ping‐Chung , Chuang Wen‐Hsiao , Tu Chih‐Ching , Lee Kuo‐Kau
Published: August 2010

An extracellular lethal toxin produced by Aeromonas hydrophila strain RT860715K originally isolated from diseased rainbow trout (Oncorhynchus mykiss) was purified by using Fast Protein Liquid Chromatography system with hydrophobic interaction chromatography and anion exchange columns. The toxin was a cysteine protease, inhibited by L ‐cysteine, iodoacetic acid, N ‐ethylamleimide, P‐chloromercuibenzene‐sulfonic acid and N‐α‐p‐tosyl‐1‐lysine‐chloromethyl ketone (TLCK), and showed maximal activity at pH 6.0. The molecular weight of the purified enzyme proved to be 94 kDa as estimated by SDS‐PAGE. In addition, the toxin was also completely inhibited by HgCl2 but partially inhibited by ethylenediamine tetraacetic acid (EDTA) and CuCl2. Both the extracellular products of Aeromonas hydrophila RT860715K and the purified protease were lethal to rainbow trout (weighing 18 g) with LD50 values of 2.87 and 0.93 μg protein g–1 fish body weight, respectively. The addition of L‐cysteine completely inhibited the lethal toxicity of the purified protease, indicating that this cysteine protease was a lethal toxin produced by the bacterium. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Isolation and characterization of an extremely long tail Thermus bacteriophage from Tengchong hot springs in China
Authors: Lin Lianbing , Hong Wei , Ji Xiuling , Han Jian , Huang Li , Wei Yunlin
Published: August 2010

Thermus strains are regarded as models to investigate the mechanism of thermostability of thermophiles, and phages from Thermus are particularly interesting because of their way to regulate gene expression. In this research, a Thermus bacteriophage named TSP4 (Thermus Siphoviridae phage) was isolated from Tengchong hot springs in China, and characteristics of morphology, temperature for phage production, pH and organic solvent sensitivity, DNA restriction endonuclease digestion and protein composition of TSP4 were further studied. TSP4 belonged to the Siphoviridae family and had a hexagonal head of 73 nm in diameter, an extremely long and flexible tail of 785 nm in length and 10 nm in width. TSP4 was very stable at 65 °C and pH 7.6. The capsid was apparently devoid of lipid. By SDS‐PAGE, six protein bands were found in purified virions. Despite their exceptional habitats separated by thousands of kilometers, the characteristics of this thermophilic phage showed high similarity to Thermus siphoviruses P23‐45 and P74‐26 isolated from Kamchatka peninsula hot springs in the Far East, Russia. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
DFT and MP2 based quantum mechanical calculations and a theoretical vibrational spectroscopic investigation on roscovitine, a potential drug to treat cancers
Authors: Balci K. , Akkaya Y. , Akyuz S. , Palavan‐Unsal N.
Published: August 2010

Theoretically possible stable conformers of free roscovitine molecule in its electronic ground state were searched by means of molecular dynamics and energy minimization calculations performed using the MM2 force field. Afterwards, geometry optimization and thermochemistry calculations were carried out at room temperature for each of the found minimum‐energy conformers using the MP2 and DFT based electronic structure methods and different Pople‐style basis sets. The results obtained from these calculations confirmed that the strong intramolecular hydrogen bonding between the purine‐nitrogen and hydroxyl‐hydrogen atoms plays an important role on the rigidity of roscovitine molecule and causes a dramatic reduction in the number of the possible stable conformers of this molecule at room temperature. Furthermore, the same calculation results also revealed that two of the found seven stable conformers are considerably more favorable in energy than the others and thus dominate the experimental room‐temperature spectra of the molecule. In the light of the theoretical vibrational spectral data obtained for these two conformers, a successful assignment of the fundamental bands observed in the experimental IR and Raman spectra recorded at room temperature for solid roscovitine and for its ethanol solution is given, and the effects of the substitution and intramolecular hydrogen bonding on the fundamental bands associated with purine and phenyl group vibrations are discussed in detail. In the fitting of the calculated harmonic wavenumbers to the corresponding experimental wavenumbers, two different scaling procedures, called ‘dual scale factors’ and ‘Scaled Quantum Mechanical Force Field (SQM FF) methodology’, were applied independently. Both procedures yielded results generally in good agreement with the experiment; however, the SQM FF methodology proved its superiority over the other. Copyright © 2010 John Wiley & Sons, Ltd.
Self‐association and hydrogen bonding of propionaldehyde in binary mixtures with water and methanol investigated by concentration‐dependent polarized Raman study and DFT calculations
Authors: Singh Dheeraj K. , Srivastava Sunil K. , Schlücker S. , Singh Ranjan K. , Asthana B. P.
Published: August 2010

The Raman spectra of neat propionaldehyde [CH3CH2CHO or propanal (Pr)] and its binary mixtures with hydrogen‐donor solvents, water (W) and methanol (M), [CH3CH2CHO + H2O] and CH3CH2CHO + CH3OH] with different mole fractions of the reference system, Pr varying from 0.1 to 0.9 at a regular interval of 0.1, were recorded in the ν(CO) stretching region, 1600–1800 cm−1. The isotropic parts of the Raman spectra were analyzed for both the cases. The wavenumber positions and line widths of the component bands were determined by a rigorous line‐shape analysis, and the peaks corresponding to self‐associated and hydrogen‐bonded species were identified. Raman peak at ∼1721 cm−1 in neat Pr, which has been attributed to the self‐associated species, downshifts slightly (∼1 cm−1) in going from mole fraction 0.9 to 0.6 in (Pr + W) binary mixture, but on further dilution it shows a sudden downshift of ∼7 cm−1. This has been attributed to the low solubility of Pr in W (∼30%), which does not permit a hydrogen‐bonded network to form at higher concentrations of Pr. A significant decrease in the intensity of this peak in the Raman spectra of Pr in a nonpolar solvent, n‐heptane, at high dilution (C = 0.05) further confirms that this peak corresponds to the self‐associated species. In case of the (Pr + M) binary mixture, however, the spectral changes with concentration show a rather regular trend and no special features were observed. Copyright © 2010 John Wiley & Sons, Ltd.
Exposure to traumatic events among treatment‐seeking, alcohol‐dependent women and men without PTSD
Authors: Johnson Candace S. , Heffner Jaimee L. , Blom Thomas J. , Anthenelli Robert M.
Published: August 2010

The authors examined lifetime exposure to a range of traumatic events in 106 abstinent, treatment‐engaged (85% residential; 15% outpatient), alcohol‐dependent women (n = 53) and men without current or lifetime posttraumatic stress disorder. Alcohol‐dependent women reported greater severity of childhood trauma, but similar lifetime exposure to traumatic events compared with men. Alcohol‐dependent women without cocaine abuse or TB (n = 10) reported greater severity of childhood trauma than women with (n = 43), and men with (n = 21) or without (n = 32) cocaine abuse or dependence. Results extend previously observed gender differences in trauma histories among alcohol‐dependent adults and point to potential gender‐ and substance‐specific drug coaddiction effects that may have been influenced by trauma exposure.
An analysis of hearing aid fittings in adults using cochlear implants and contralateral hearing aids
Authors: Harris Michael S. , Hay‐McCutcheon Marcia
Published: August 2010

Objectives/Hypothesis:

The objective of this study was to assess the appropriateness of hearing aid fittings within a sample of adult cochlear implant recipients who use a hearing aid in the contralateral ear (i.e., bimodal stimulation).

Methods:

The hearing aid gain was measured using real ear testing for 14 postlingually deaf English‐speaking adults who use a cochlear implant in the contralateral ear. Unaided and aided audiometric testing assessed the degree of functional gain derived from hearing aid use.

Results:

On average, the target to actual output level difference was within 10 dB only at frequencies of 750 Hz and 1,000 Hz. Only 1 of the 14 study participants had a hearing aid for which the majority of the tested frequencies were within 10 dB of the target gain. In addition, a greater amount of functional gain (i.e., the increase in unaided behavioral thresholds after amplification) was provided for lower frequencies than higher frequencies.

Conclusions:

Hearing aid settings in our sample were suboptimal and may be regarded as a contributing factor to the variability in bimodal benefit. Refining hearing aid fitting strategies tailored to the needs of the concurrent cochlear implant and hearing aid user is recommended. Laryngoscope, 2010
A randomized double‐blind controlled trial of phosphorylcholine‐coated tympanostomy tube versus standard tympanostomy tube in children with recurrent acute and chronic otitis media
Authors: Hong Paul , Smith Neil , Johnson Liane B. , Corsten Gerard
Published: August 2010

Objective:

To compare the postoperative complication rates of phosphorylcholine‐coated fluoroplastic tympanostomy tubes versus uncoated fluoroplastic tympanostomy tubes.

Methods:

A prospective randomized double‐blind controlled trial in children with recurrent acute otitis media and chronic otitis media with effusion; 240 children were randomized to receive a phosphorylcholine‐coated tube in one ear and an uncoated tube in the other. Postoperatively, patients were assessed at 2 weeks and 4, 8, 12, 18, and 24 months to ascertain the incidence of otorrhea, tube lumen blockage, and early extrusion.

Results:

Out of 240 children, 5 withdrew and 16 were lost to early follow‐up. The mean age was 43.8 months. There were no statistically significant differences in the incidence of postoperative otorrhea, tube blockage, and extrusion.

Conclusions:

Phosphorylcholine‐coated fluoroplastic ventilation tubes do not offer any advantages over uncoated standard fluoroplastic tympanostomy tubes. Laryngoscope, 2011
Uvulopalatal flap for obstructive sleep apnea: Short‐term and long‐term results
Authors: Neruntarat Chairat
Published: August 2010

Objective:

To study long‐term results in patients undergoing uvulopalatal flap (UPF) for obstructive sleep apnea (OSA).

Design:

Prospective, clinical trial at tertiary referral center.

Material and Methods:

A study was undertaken on 83 OSA patients with palatal obstruction based on radiography and physical findings. UPF was conducted to increase the airway space and data were analyzed.

Results:

Patients had a mean age of 36.5 ± 12.3 years and a mean body mass index (BMI) of 29.4 ± 4.3 kg/m2. The mean follow‐up was 54.2 ± 8.9 months, with a range of 48 to 62 months. The mean baseline apnea‐hypopnea index (AHI), short‐term AHI, and long‐term AHI were 45.6 ± 10.3, 13.4 ± 5.2, and 19.4 ± 5.1, respectively. The mean baseline lowest oxygen saturation (LSAT), short‐term LSAT, and long‐term LSAT were 82.6 ± 5.4%, 89.2 ± 4.8%, and 88.1 ± 3.2%, respectively. Forty‐three patients (51.8%) had long‐term success, and 15 patients(25.8%) had an increase in the AHI over the follow‐up period such that they were no longer considered success by traditional AHI criteria. Serious complications were not encountered.

Conclusions:

UPF is a safe and effective procedure that results in long‐term success for OSA. However, a regular follow‐up is important because some patients will relapse in the long term. Laryngoscope, 2011
Reevaluation of gastroesophageal reflux disease as a risk factor for laryngeal cancer
Authors: Francis David O. , Maynard Charles , Weymuller Ernest A. , Reiber Gayle , Merati Albert L. , Yueh Bevan
Published: August 2010

Objectives/Hypothesis:

The relationship between gastroesophageal reflux disease (GERD) and laryngeal cancer has not been fully elucidated. This case‐control study investigates whether GERD increases the odds of developing these malignancies.

Study Design:

Case‐control study.

Methods:

Rates of GERD among cases of laryngeal cancer identified in the Veterans Health Administration outpatient care files (year 2000–2006) were compared with controls. Cases (N = 14,449) were frequency matched 1:1 with controls. Multivariate logistic regression was used to determine the association between GERD and cancer.

Results:

After adjusting for tobacco and/or alcohol use, there was no association between GERD and laryngeal cancer (adjusted odds ratio, 1.01; 95% confidence interval, 0.92‐1.12, P =.780). Although an association was found when time from GERD diagnosis to malignancy was less than 3 months, it disappeared when this period was extended further.

Conclusions:

In this population, there was no increased risk of laryngeal cancer among patients with GERD. However, in subsite analysis, a possible relationship between GERD and glottic cancer was observed. Reverse causality must be considered in future studies assessing the relationship between reflux and laryngeal cancer to limit misclassification bias. Laryngoscope, 2011
Six-minute walk distance predicts mortality in liver transplant candidates
Authors: Carey Elizabeth J. , Steidley Eric D. , Aqel Bashar A. , Byrne Thomas J. , Mekeel Kristin L. , Rakela Jorge , Vargas Hugo E. , Douglas David D.
Published: August 2010

The 6-minute walk distance (6MWD) is a simple test measuring global physical function. It is commonly used to predict mortality in patients with cardiac and pulmonary diseases, but it is also useful in assessing the functional status of patients with a variety of other medical conditions. We sought to determine (1) the characteristics of the 6MWD in patients listed for liver transplantation (LT), (2) the existence of a relationship between the 6MWD and the quality of life, and (3) the relationship between the 6MWD and survival in LT candidates. The 6MWD was prospectively measured in all patients listed for LT. The 6MWD was determined when the listed Model for End-Stage Liver Disease (MELD) score was ≥15. Patients were followed until LT, death, removal from the wait list, or the end of the study period. Quality of life was assessed with the Short Form 36 (SF-36). In 121 patients, the mean 6MWD was 369 ± 122 m; it was not related to age, height, weight, body mass index, albumin level, or etiology of liver disease and showed a moderate correlation with the physical component score (PCS) on the SF-36 (r = 0.4) and a moderate inverse correlation with the native MELD score (r = −0.61). In an unadjusted analysis, a high native MELD score, a low 6MWD, and a low PCS were associated with mortality, with only the 6MWD retaining significance after adjustment for covariates. Each 100-m increase in the 6MWD was significantly associated with increased survival (hazard ratio = 0.48, P = 0.0001), with 6MWD < 250 m being associated with an increased risk of death (P = 0.0001). In conclusion, the 6MWD is significantly reduced in patients awaiting LT and is inversely correlated with the native MELD score. A pretransplant 6MWD < 250 m is a risk for death on the wait list. Liver Transpl 16:1373–1378, 2010. © 2010 AASLD.
Auxiliary partial orthotopic living donor liver transplantation with a small-for-size graft for congenital absence of the portal vein
Authors: Matsuura Toshiharu , Soejima Yuji , Taguchi Tomoaki
Published: August 2010

Congenital absence of the portal vein (CAPV) with an extrahepatic portosystemic shunt is a rare malformation; the completely absent type, Abernethy malformation type I, is especially rare. Liver transplantation for CAPV type I has been recently recognized as the only curative operation, but few reports have been published so far; meanwhile, auxiliary partial orthotopic liver transplantation (APOLT) has been proposed to be a very effective option, especially for pediatric patients. Here we present an 18-year-old adult patient with CAPV, asplenia, and an iliac shunt vessel who was managed successfully with APOLT using a small-for-size graft. To the best of our knowledge, this is the first adult patient who has experienced success with APOLT for CAPV. This is a feasible procedure: it not only fulfills the metabolic demands of the liver for adult patients but also potentially cures CAPV. Liver Transpl 16:1437–1439, 2010. © 2010 AASLD.
Effect of Poly(3‐octylthiophene) Doping on the Attachment and Proliferation of Osteoblasts
Authors: Rincón Charlene , Chen Chien‐Chiang , Meredith J. Carson
Published: August 2010

The effect of doping P3OT with ferric chloride on the attachment and proliferation of MC3T3‐E1 osteoblasts is reported. Cell density and area correlated strongly with doping concentration: cells were larger and exhibited better spreading as doping increased. Cells cultured on undoped P3OT showed a decrease in proliferation between 24 and 48 h followed by a recovery after 72 h. However, this trend diminished with increasing doping concentration, and disappeared completely at the highest dopant level investigated. Analysis of cell‐cell spatial distributions suggested that contact inhibition of proliferation occurred similarly on both undoped and doped P3OT. From these results, FeCl3‐doping had no significant deleterious effect on attachment or proliferation of osteoblasts in vitro.

magnified image
Coherence regularization for SENSE reconstruction with a nonlocal operator (CORNOL)
Authors: Fang Sheng , Ying Kui , Zhao Li , Cheng Jianping
Published: August 2010

The sensitivity encoding (SENSE) reconstruction reconstruction of parallel imaging can suffer from amplified noise at high reduction factors due to the ill‐conditioned system matrix. Regularization alleviates this problem by imposing priors on the reconstructed image. These priors typically introduce both intrastructure smoothness and interstructure smoothness. The former mainly reduces noise, while the latter can also decrease intensity changes between different structures and cause structure loss. In this study, coherence regularization was proposed to impose only intrastructure smoothness in order to enhance the preservation of the image structure. Its energy functional was formed by examining the connection between regularization and the diffusion equation of adaptive image filtering. The coherence regularization extracts image structure information directly from the noisy data by adapting diffusion equation–related image‐filtering methods. In this study, a nonlocal operator derived from the nonlocal mean filter was used for structure detection. Based on this structure information, only intrastructure intensity changes are penalized while the interstructure intensity changes are preserved. Both phantom simulation and in vivo experiments demonstrate that the coherence regularization would be able to effectively suppress noise in SENSE reconstruction at high reduction factors while suffering from much less image degradation, compared to Tikhonov and total variation methods. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
The one‐warehouse multiretailer problem with an order‐up‐to level inventory policy
Authors: Solyalı Og̀uz , Süral Haldun , Denizel Meltem
Published: August 2010

We consider a two‐level system in which a warehouse manages the inventories of multiple retailers. Each retailer employs an order‐up‐to level inventory policy over T periods and faces an external demand which is dynamic and known. A retailer's inventory should be raised to its maximum limit when replenished. The problem is to jointly decide on replenishment times and quantities of warehouse and retailers so as to minimize the total costs in the system. Unlike the case in the single level lot‐sizing problem, we cannot assume that the initial inventory will be zero without loss of generality. We propose a strong mixed integer program formulation for the problem with zero and nonzero initial inventories at the warehouse. The strong formulation for the zero initial inventory case has only T binary variables and represents the convex hull of the feasible region of the problem when there is only one retailer. Computational results with a state‐of‐the art solver reveal that our formulations are very effective in solving large‐size instances to optimality. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010
Order within disorder: Aggrecan chondroitin sulphate‐attachment region provides new structural insights into protein sequences classified as disordered
Authors: Jowitt Thomas A. , Murdoch Alan D. , Baldock Clair , Berry Richard , Day Joanna M. , Hardingham Timothy E.
Published: August 2010

Structural investigation of proteins containing large stretches of sequences without predicted secondary structure is the focus of much increased attention. Here, we have produced an unglycosylated 30 kDa peptide from the chondroitin sulphate (CS)‐attachment region of human aggrecan (CS‐peptide), which was predicted to be intrinsically disordered and compared its structure with the adjacent aggrecan G3 domain. Biophysical analyses, including analytical ultracentrifugation, light scattering, and circular dichroism showed that the CS‐peptide had an elongated and stiffened conformation in contrast to the globular G3 domain. The results suggested that it contained significant secondary structure, which was sensitive to urea, and we propose that the CS‐peptide forms an elongated wormlike molecule based on a dynamic range of energetically equivalent secondary structures stabilized by hydrogen bonds. The dimensions of the structure predicted from small‐angle X‐ray scattering analysis were compatible with EM images of fully glycosylated aggrecan and a partly glycosylated aggrecan CS2‐G3 construct. The semiordered structure identified in CS‐peptide was not predicted by common structural algorithms and identified a potentially distinct class of semiordered structure within sequences currently identified as disordered. Sequence comparisons suggested some evidence for comparable structures in proteins encoded by other genes (PRG4, MUC5B, and CBP). The function of these semiordered sequences may serve to spatially position attached folded modules and/or to present polypeptides for modification, such as glycosylation, and to provide templates for the multiple pleiotropic interactions proposed for disordered proteins. Proteins 2010. © 2010 Wiley‐Liss, Inc.
Phase transition, microstructure and electric‐field‐induced large strain in Bi0.5(Na0.85K0.15)0.5TiO3–BiAlO3 lead‐free piezoelectric ceramics
Authors: Ullah Aman , Ahn Chang Won , Kim Ill Won
Published: August 2010

Lead‐free (1 − x)(Bi0.5(Na0.85K0.15)0.5TiO3)‐xBiAlO3 (abbreviated as BNKT15‐BA, x = 0, 0.025, 0.050, 0.075, 0.100) piezoelectric ceramics were synthesized by a conventional solid‐state reaction method. The phase‐transition behavior in BNKT15‐BA ceramics with respect to changes in composition were investigated using X‐ray diffraction analysis, dielectric and ferroelectric characterizations, and electric‐field‐induced strain. The results of X‐ray diffraction revealed that a pure perovskite phase was formed for x ≤ 0.050. A phase transition from the coexistence of rhombohedral and tetragonal to a pseudocubic phase was observed at x = 0.050. The dielectric constant continuously decreased with increasing BA content, and the depolarization temperature (Td) was shifted towards lower temperature. The polarization and strain hysteresis loops indicate that the ferroelectric order of BNKT15 ceramics is disrupted significantly with the addition of BA. The destabilization of ferroelectric order is accompanied by an enhancement of bipolar and unipolar strains, and a large electric‐field‐induced strain (S = 0.21%) and a normalized strain ($d_{33}^{*} $ = Smax/Emax = 276 pm/V) were obtained at x = 0.050. These results suggested that the BNKT15‐BA system can be employed in lead‐free electromechanical devices.
Characterization of Au‐metal nanoparticle‐hybridized poly (3,4‐ethylenedioxythiophene) films for electrochromic devices
Authors: Lee Jong Seok , Choi Yong‐June , Wang Seok‐Joo , Park Hyung‐Ho , Pyun Jae Chul
Published: August 2010

In order to enhance the electrochromic properties of poly (3,4‐ethylenedioxythiophene) (PEDOT), Au/PEDOT nano‐hybrid thin films were prepared from a Au nanoparticle (Au NP), 3,4‐ethylenedioxythiophene (EDOT), iron p‐toluenesulfonate and imidazole mixture. The incorporation of Au NPs slightly affected the surface roughness of PEDOT films but had an important impact on the conjugation length and packing density of PEDOT due to the physical volume effect. An enhancement in the electrochromic properties of PEDOT was obtained, in particular, a 50% reduction in the switching speed of PEDOT with a blue shift of the maximum absorption peak in the ultra violet‐visible spectroscopic analysis.
The ECMWF re‐analysis for the AMMA observational campaign
Authors: Agustí‐Panareda Anna , Beljaars Anton , Ahlgrimm Maike , Balsamo Gianpaolo , Bock Olivier , Forbes Richard , Ghelli Anna , Guichard Françoise , Köhler Martin , Meynadier Remi , Morcrette Jean‐Jacques
Published: August 2010

During the 2006 African Monsoon Multidisciplinary Analysis (AMMA) field experiment, an unprecedented number of soundings were performed in West Africa. However, due to technical problems many of these soundings did not reach the Global Telecommunication System and therefore they could not be included in the operational numerical weather prediction (NWP) analyses. This issue, together with the realization that there was a significant bias in the radiosonde humidity, led to the conclusion that a re‐analysis effort was necessary. This re‐analysis was performed at the European Centre for Medium‐Range Weather Forecasts (ECMWF) spanning the wet monsoon season of 2006 from May–September. The key features of the ECMWF AMMA re‐analysis are presented, including the use of a newer model version with improved physics, all the AMMA radiosonde data available from the AMMA database and a new radiosonde humidity bias‐correction scheme. Data‐impact experiments show that there is a benefit from these observations, but also highlight large model physics biases over the Sahel that cause a short‐lived impact of the observations on the model forecast. The AMMA re‐analysis is compared with independent observations to investigate the biases in the different parts of the physics. In the framework of the AMMA project, a hybrid dataset was developed to provide a best estimate of the different terms of the water cycle. This hybrid dataset is used to evaluate the improvement achieved from the use of extra AMMA observations and of a radiosonde humidity bias‐correction scheme in the water cycle of the West African monsoon. Finally, future model developments that offer promising improvements in the water cycle are discussed. Copyright © 2010 Royal Meteorological Society
Can 4D‐Var use dynamical information from targeted observations of a baroclinic structure?
Authors: Irvine E. A. , Gray S. L. , Methven J.
Published: August 2010

Targeted observations are generally taken in regions of high baroclinicity, but often show little impact. One plausible explanation is that important dynamical information, such as upshear tilt, is not extracted from the targeted observations by the data assimilation scheme and used to correct initial condition error. This is investigated by generating pseudo targeted observations which contain a singular vector (SV) structure that is not present in the background field or routine observations, i.e. assuming that the background has an initial condition error with tilted growing structure. Experiments were performed for a single case‐study with varying numbers of pseudo targeted observations. These were assimilated by the Met Office four‐dimensional variational (4D‐Var) data assimilation scheme, which uses a 6 h window for observations and background‐error covariances calculated using the National Meteorological Centre (NMC) method. The forecasts were run using the operational Met Office Unified Model on a 24 km grid. The results presented clearly demonstrate that a 6 h window 4D‐Var system is capable of extracting baroclinic information from a limited set of observations and using it to correct initial condition error. To capture the SV structure well (projection of 0.72 in total energy), 50 sondes over an area of 1×106 km2 were required. When the SV was represented by only eight sondes along an example targeting flight track covering a smaller area, the projection onto the SV structure was lower; the resulting forecast perturbations showed an SV structure with increased tilt and reduced initial energy. The total energy contained in the perturbations decreased as the SV structure was less well described by the set of observations (i.e. as fewer pseudo observations were assimilated). The assimilated perturbation had lower energy than the SV unless the pseudo observations were assimilated with the dropsonde observation errors halved from operational values. Copyright © 2010 Royal Meteorological Society
Structure, stability, and dynamics of hydrogen polyoxides
Authors: Martins‐Costa Marilia , Anglada Josep M. , Ruiz‐López Manuel F.
Published: August 2010

Hydrogen polyoxides H2On have been theoretically studied in gas phase and in aqueous solution. Structures up to n = 4 have been detected experimentally. Larger systems are speculative till now but previous calculations predicted stable structures. Minimum energy geometries and formation enthalpies for n = 3–10 have been calculated in gas phase using high‐level ab initio calculations that include DFT, QCISD, and CCSD(T) methods. Formation enthalpies are negative for n < 5, close to zero for n = 5, and positive for n > 5. They go up by ∼12–16 kcal/mol per O atom although the increase is not regular; it presents an oscillatory behavior that is clearly connected with odd/even effects reported for OO bond lengths. Computations in aqueous solution focus on free energies of solvation, solute–solvent hydrogen bonds strength, and solvent effects on polyoxide structure. We use two solvent models. A dielectric continuum implicit model is used to estimate free energies of solvation at an affordable cost. An explicit model is then used combining a QM/MM description of the solution and molecular dynamics (MD) simulations for polyoxides n = 3–6. The solute is described at the DFT level whereas solvent molecules are treated with an empirical force field. The analysis of the solute dynamics in solution shows that the systems are very good proton donors but poor proton acceptors. The structure with n = 5 exhibits a particular behavior that seems to be related with its larger statistical probability of forming intramolecular hydrogen bonds. Most bonds are lengthened in solution, especially the polar HO bonds and the inner OO bonds. Remarkably, the amplitude of OO bond length fluctuations has been shown to depend primarily on its position along the chain, that is, the distance with respect to the terminal HO bond, and less on chain length. For n = 6, the central OO bond fluctuates between 1.2 and 1.9 Å. Chains beyond n = 6 should be extremely labile since fluctuations of the central OO bonds should be even larger. Hence, if formed, the corresponding lifetimes should be extremely short. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Electronic states of hydrogen atom in tetrahedral and similar polyhedral cavities
Authors: Pupyshev Vladimir I.
Published: August 2010

Electronic states of an atomic particle situated inside an impenetrable cavity of a simple polyhedral form are studied. The numerical method used here for calculations and its theoretical backgrounds are presented. Numerical estimates for the energy levels of a hydrogen atom inside impenetrable cavities of a tetrahedral, cubic, or more complex shape corresponding to truncated polyhedrons are described. The state ordering of the lowest electronic states for confined hydrogen atom, associated with 1s–3d‐states of a free system, is studied with special attention to the role of the vertexes in tetrahedral cavities. Some details of the state ordering for tetrahedral, octahedral, cubic, and some other polyhedral cavities are analyzed. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
On the shape dependence of cluster (hyper)polarizabilities. A combined ab initio and DFT study on large fullerene–like gallium arsenide semiconductor clusters
Authors: Karamanis Panaghiotis , Pouchan Claude
Published: August 2010

The effect of the cluster shape on the magnitudes of the static dipole (hyper)polarizabilities of large gallium arsenic clusters built from 72 atoms is presented and discussed. Also, the performance of conventional and long range corrected density functionals is assessed on the prediction of the static electric dipole hyperpolarizabilities. The reported results obtained at the Hartree‐Fock, (LC‐) BLYP, (LC‐) BPW91, (CAM)‐B3LYP, and WB97XD levels of theory demonstrate that the cluster shape not only dominates the magnitude of the second hyperpolarizabilities of clusters but also affects dramatically the performance of the density functional theory functionals used. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Experimental analysis of the effective components of problem‐based learning
Authors: Pease María A. , Kuhn Deanna
Published: August 2010

Problem‐based learning (PBL) is widely endorsed as a desirable learning method, particularly in science. Especially in light of the method's heavy demand on resources, evidence‐based practice is called for. Rigorous studies of the method's effectiveness, however, are scarce. In Study 1, college students enrolled in an elementary physics course participated in 7 hours of instruction on two concepts, one (electromagnetic field) via a PBL method and the other (gravitational field) via a lecture/discussion method. A comparison class enrolled in the same course with the same instructor underwent the identical experience except that matching of concept and method was reversed. Multiple assessments over time showed superior mastery of the concept learned via PBL for both groups. In Study 2, using a subtractive method, we further investigated the role of specific components of the PBL method by comparing a group who worked individually using a PBL method to one who participated in the typical collaborative form of PBL. Rather than the social component typically associated with PBL, the effective component of the method appears to be the focus on engagement with a problem. © 2010 Wiley Periodicals, Inc. Sci Ed 95: 57–86, 2010.
Authenticated key exchange protocol with enhanced freshness properties
Authors: Huang Hai , Cao Zhenfu
Published: August 2010

This paper investigates the security model for authenticated key exchange protocols. We further enhance the enhanced Canetti‐Krawczyk (eCK) model by introducing a notion called strong key compromise impersonation (SKCI) resilience which is first identified in this paper. SKCI resilience guarantees that the adversary cannot masquerade as another party B to communicate with party A even if the static private key and the ephemeral private key of party A are compromised. We point out that the three‐pass authenticated key exchange protocol generically transformed from the two‐pass one secure in the eCK model cannot resist the SKCI attack. Finally, we introduce a new authenticated key exchange protocol SIG‐DH+ and prove that it satisfies our new definition. Copyright © 2010 John Wiley & Sons, Ltd.
Bio‐creep in non‐inferiority clinical trials
Authors: Everson‐Stewart Siobhan , Emerson Scott S.
Published: August 2010

After a non‐inferiority clinical trial, a new therapy may be accepted as effective, even if its treatment effect is slightly smaller than the current standard. It is therefore possible that, after a series of trials where the new therapy is slightly worse than the preceding drugs, an ineffective or harmful therapy might be incorrectly declared efficacious; this is known as ‘bio‐creep’. Several factors may influence the rate at which bio‐creep occurs, including the distribution of the effects of the new agents being tested and how that changes over time, the choice of active comparator, the method used to account for the variability of the estimate of the effect of the active comparator, and changes in the effect of the active comparator from one trial to the next (violations of the constancy assumption). We performed a simulation study to examine which of these factors might lead to bio‐creep and found that bio‐creep was rare, except when the constancy assumption was violated. Copyright © 2010 John Wiley & Sons, Ltd.
Cement‐related particles interact with proinflammatory IL‐8 chemokine from human primary oropharyngeal mucosa cells and human epithelial lung cancer cell line A549
Authors: Bauer Mario , Gräbsch Carolin , Gminski Richard , Ollmann Ariane I.H. , Borm Paul , Dietz Andreas , Herbarth Olf , Wichmann Gunnar
Published: August 2010

Epidemiological studies have shown that respirable exposure to emitted cement particulate matter is associated with adverse health risk for human. The underlying mechanisms, however, are poorly understood. To examine the effect of cement, nine blinded cement‐related particulates (<10 μm) were assessed with regard to their induction of the proinflammatory cytokines IL‐6 and IL‐8 in human primary epithelial cells (pEC) from oropharyngeal mucosa as well as from nonsmall‐cell lung carcinoma (non‐SCLC) cells A549. It was demonstrated that the cement specimens did not act cytotoxic as assessed by the lactate dehydrogenase (LDH) assay. The basal and IL‐1β‐induced IL‐8 expression was suppressed, in contrast to an unchanged IL‐6. At the transcript level the basal and induced IL‐6 and IL‐8 gene expression was not influenced by cement dust. To discover the mechanism by which cement influenced the IL‐8 expression the following experiments were performed. Submerse exposure experiments have shown that the release of IL‐8 was suppressed by cement dust. Furthermore, the incubation of IL‐8 with cement‐related specimens under cell‐free condition led to a loss of immunoreactive IL‐8. An immunological masking of IL‐8 by free soluble components of respiratory epithelial cells was excluded. Thus, the decrease of IL‐8 protein content after cement exposure seems to be a result of the adsorption of IL‐8 protein to cement particles and the inhibition of IL‐8 release. In conclusion, due to absent cytotoxic and inflammatory effects of cement‐related specimens in both human pEC and A549 cell models it remains open how cement exposure may lead to the respiratory adverse effects in humans. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Comment on “Free convective flow between vertical porous plates with periodic heat input” by B. K. Jha and A. O. Ajibade, ZAMM 90, 185–193 (2010)
Authors: Magyari E.
Published: August 2010

In a recent paper by B. K. Jha and A. O. Ajibade (ZAMM 90, 185–193 2010) the title problem for the fully developed flow regime was investigated and exact analytical solutions for the velocity and temperature fields were reported. However, when the Prandtl number equals unity, some coefficients become singular and thus the velocity solution of Jha and Ajibade cannot be evaluated by a direct substitution of Pr = 1. The main goal of the present note is (i) to show how the singularities can be removed, (ii) to give the corresponding nonsingular velocity solutions in an explicit form, and (iii) to discuss the mathematical and physical origin of this kind of singularity in the fluid and point mechanical problems.
Real‐Time Ultrasound‐Aided Central Vein Cannulation Failure Rate: Establishing a Benchmark
Authors: Requarth Jay A.
Published: August 2010

Background

The use of real‐time two‐dimensional B‐mode ultrasound (RTUS)‐aided central venous access device (CVAD) insertion has been recommended by health‐care agencies, but a realistic failure rate for bedside attempts is unknown.

Methods

The failure rate of RTUS‐aided CVAD insertion is estimated using data from adult inpatients and outpatients referred to a tertiary referral radiology department for a new CVAD insertion during the 2.5‐year period ending February 29, 2008. Cannulation failure, complications, and additional fluoroscopic interventions per central vein cannulation attempt and per patient encounter were retrospectively collected and evaluated.

Results

Of the 2456 consecutive patient encounters, the index central vein cannulation failure rate using only RTUS and fluoroscopy was 4.8%; ultimate failure rate was 0.3%. The procedural mortality rate was 0.04%. If the index upper‐body central vein cannulation failed, an ipsilateral upper‐body attempt through a different central vein failed in 63.6%, whereas a contralateral upper‐body attempt failed in 26.7% (p = 0.11) and a common femoral vein attempt failed in 11.5% (p = 0.0039).

Conclusions

The minimum bedside failure rate of RTUS‐aided CVAD insertion is 4.8% for the index central vein cannulated. The ultimate failure rate of 0.3% and the mortality rate of 0.04% are due to RTUS, fluoroscopy, and the additional equipment available in an IR suite. If the upper‐body index central vein cannulation fails, cannulation of the common femoral vein is more likely to succeed than additional attempts in other ipsilateral upper‐body central veins.
Chronic blockade of interleukin‐1 (IL‐1) prevents and attenuates neuropathic pain behavior and spontaneous ectopic neuronal activity following nerve injury
Authors: Gabayl Eran , Wolfl Gilly , Shavitl Yehuda , Yirmiyal Raz , Tall Michael
Published: August 2010

Neuropathic pain is a chronic pain state resulting from peripheral nerve injury, characterized by hyperalgesia and allodynia. We have reported that mice with genetic impairment of IL‐1 signaling display attenuated neuropathic pain behavior and ectopic neuronal activity. In order to substantiate the role of IL‐1 in neuropathic pain, WT mice were implanted subcutaneously with osmotic micropumps containing either IL‐1ra or vehicle. Two days following the implantation, two models of neuropathic pain were used; partial nerve injury (spinal nerve transection, SNT), or complete nerve cut (spinal neuroma model). Mechanosensitivity was assessed seven consecutive days following SNT, and on day 7 recordings of spontaneous ectopic activity were performed. In the spinal nerve neuroma model, autotomy scores were recorded up to 35 days. Vehicle‐treated mice developed significant allodynia and autotomy, and clear ectopic activity (4.1±1.1% of the axons); whereas IL‐1ra‐treated mice did not display allodynic response, displayed delayed onset of autotomy and markedly reduced severity of autotomy scores, and displayed reduced spontaneous activity (0.8±0.4% of the axons). To test whether IL‐1 is involved in maintenance of mechanical allodynia, a separate group of WT mice was treated with a single injection of either saline or IL‐1ra four days following SNT, after the allodynic response was already manifested. Whereas saline‐treated mice displayed robust allodynia, acute IL‐1ra treatment induced long‐lasting attenuation of the allodynic response. The results support our hypothesis that IL‐1 signaling plays an important role in neuropathic pain and in the ectopic neuronal activity that underling its development.
Diffraction Imaging in a He+ Ion Beam Scanning Transmission Microscope
Authors: IV John Notte , Hill Raymond , McVey Sean M. , Ramachandra Ranjan , Griffin Brendan , Joy David
Published: August 2010

The scanning helium ion microscope has been used in transmission mode to investigate both the feasibility of this approach and the utility of the signal content and the image information available. Operating at 40 keV the penetration of the ion beam, and the imaging resolution achieved, in MgO crystals was found to be in good agreement with values predicted by Monte Carlo modeling. The bright-field and annular dark-field signals displayed the anticipated contrasts associated with beam absorption and scattering. In addition, the diffraction of the He ion beam within the sample gave rise to crystallographic contrast effects in the form of thickness fringes and dislocation images. Scanning transmission He ion microscopy thus achieves useful sample penetration and provides nanometer scale resolution, high contrast images of crystalline materials and crystal defects even at modest beam energies.