bluuebunny/crossref_metadata_2025 huggingface dataset:
The On-Freezing Phenomenon: Cognitive and Behavioral Aspects
Authors: Moretti Rita , Torre Paola , Antonello Rodolfo M. , Esposito Francesca , Bellini Giuseppe
Published: August 2011

Freezing of gait is a warning sign of Parkinson's disease. One could distinguish off-freezing, which is associated with dopaminergic therapy and to its titration, and it is clinically related to wearing-off phenomenon. Differently, the on-freezing phenomenon seems to be related to a neural disruption of the frontal-parietal-basal ganglia-pontine projections; clinically, it does not respond to therapy modifications or to different drug titration. In a group of patients with on-freezing, we have detected an alteration of focusing attention, an impairment of set-shifting, in addition to poor abstract reasoning and a reduction of planning. These aspects have been even more evident, when compared with the results obtained by a group of PD patients, without freezing.
Metformin-Associated Acute Kidney Injury and Lactic Acidosis
Authors: Arroyo David , Melero Rosa , Panizo Nayara , Goicoechea Marian , Rodríguez-Benítez Patrocinio , Vinuesa Soledad García , Verde Eduardo , Tejedor Alberto , Luño José
Published: August 2011

Objectives. Metformin is the preferred oral antidiabetic agent for type 2 diabetes. Lactic acidosis is described as a rare complication, usually during an acute kidney injury (AKI).Material and Methods. We conducted a prospective observational study of metformin-associated AKI cases during four years. 29 cases were identified. Previous renal function, clinical data, and outcomes were recorded.Results. An episode of acute gastroenteritis precipitated the event in 26 cases. Three developed a septic shock. Three patients died, the only related factor being liver dysfunction. More severe metabolic acidosis hyperkalemia and anemia were associated with higher probabilities of RRT requirement. We could not find any relationship between previous renal dysfunction and the outcome of the AKI.Conclusions. AKI associated to an episode of volume depletion due to gastrointestinal losses is a serious complication in type 2 diabetic patients on metformin. Previous renal dysfunction (mild-to-moderate CKD) has no influence on the severity or outcome.
Personality and Longevity: Knowns, Unknowns, and Implications for Public Health and Personalized Medicine
Authors: Chapman Benjamin P. , Roberts Brent , Duberstein Paul
Published: August 2011

We review evidence for links between personality traits and longevity. We provide an overview of personality for health scientists, using the primary organizing framework used in the study of personality and longevity. We then review data on various aspects of personality linked to longevity. In general, there is good evidence that higher level of conscientiousness and lower levels of hostility and Type D or “distressed” personality are associated with greater longevity. Limited evidence suggests that extraversion, openness, perceived control, and low levels of emotional suppression may be associated with longer lifespan. Findings regarding neuroticism are mixed, supporting the notion that many component(s) of neuroticism detract from life expectancy, but some components at some levels may be healthy or protective. Overall, evidence suggests various personality traits are significant predictors of longevity and points to several promising directions for further study. We conclude by discussing the implications of these links for epidemiologic research and personalized medicine and lay out a translational research agenda for integrating the psychology of individual differences into public health and medicine.
Voltammetric Determination of Acetaminophen in the Presence of Codeine and Ascorbic Acid at Layer-by-Layer MWCNT/Hydroquinone Sulfonic Acid-Overoxidized Polypyrrole Modified Glassy Carbon Electrode
Authors: Shahrokhian Saeed , Saberi Reyhaneh-Sadat
Published: August 2011

A very sensitive electrochemical sensor constructed of a glassy carbon electrode modified with a layer-by-layer MWCNT/doped-overoxidized polypyrrole (oppy/MWCNT /GCE) was used for the determination of acetaminophen (AC) in the presence of codeine and ascorbic acid (AA). In comparison to the bare glassy carbon electrode, a considerable shift in the peak potential together with an increase in the peak current was observed for AC on the surface of oppy/MWCNT/GCE, which can be related to the enlarged microscopic surface area of the electrode. The effect of the experimental conditions on the electrode response, such as types of counter ion, pyrrole and counter ion concentration, potential and number of cycles in the polymerization procedure, amount of MWCNT, and the pH, were investigated. Under the optimized conditions, the calibration curve was obtained over two concentration ranges of 2 × 10−7–6 × 10−6 M and 4 × 10−5–1 × 10−4 M of AC with a linear correlation coefficient (R2) of 0.9959 and 0.9947, respectively. The estimated detection limit (3σ) for AC was obtained as 5 × 10−8 M. The developed method was successfully applied to analyze the pharmaceutical preparations of AC, and a recovery of 95% with a relative standard deviation of 0.98% was obtained for AC.
The Roles of Alkyl Branches of Ionic Liquid in the Corrosion Resistance of Pb/Sb/Sn Grids Alloy in Lead-Acid Battery
Authors: Rezaei Behzad , Ensafi Ali Asghar , Taghipour Jahromi Ahmad Reza
Published: August 2011

This paper describes the effects of ionic liquids (ILs) including mono, bicyclohexyl, and tetrahexyl ammonium hydrogen sulphate on the corrosion behaviour of Pb/Sb/Sn grids alloy of lead-acid battery with Pb, Sb (1.66 wt%), and Sn (0.24 wt%). Electrochemical behaviour has been investigated using Tafel plots and electrochemical impedance spectroscopy with various concentrations of ILs as electrolyte additives in 4.0 mol⋅L-1sulphuric acid. The obtained results indicated that, by increasing number of alkyl or cycloalkyl branches in ILs, the corrosion rate of the lead alloy decreases, whereas inhibition efficiency shows a reverse effect. In the presence of all ILs in different concentrations, conversion current of PbSO4to PbO2(iaandic) increases, while the reversibility, deduced from peak potential differences, decreases. Also, the effect of ILs adsorption model on the corrosion behaviour of electrode was proposed.
Immobilization ofErwiniasp. D12 Cells in Alginate-Gelatin Matrix and Conversion of Sucrose into Isomaltulose Using Response Surface Methodology
Authors: Kawaguti Haroldo Yukio , Carvalho Priscila Hoffmann , Figueira Joelise Alencar , Sato Hélia Harumi
Published: August 2011

Isomaltulose is a noncariogenic reducing disaccharide and also a structural isomer of sucrose and is used by the food industry as a sucrose replacement. It is obtained through enzymatic conversion of microbial sucrose isomerase. AnErwiniasp. D12 strain is capable of converting sucrose into isomaltulose. The experimental design technique was used to study the influence of immobilization parameters on converting sucrose into isomaltulose in a batch process using shaken Erlenmeyer flasks. We assessed the effect of gelatin and transglutaminase addition on increasing the reticulation of granules ofErwiniasp. D12 cells immobilized in alginate. Independent parameters, sodium alginate concentration, cell mass concentration, CaCl2concentration, gelatin concentration, and transglutaminase concentration had all a significant effect (P<0.05) on isomaltulose production.Erwiniasp. D12 cells immobilized in 3.0% (w/v) sodium alginate, 47.0% (w/v) cell mass, 0.3 molL-1CaCl2, 1.7% (w/v) gelatin and 0.15% (w/v) transglutaminase presented sucrose conversion into isomaltulose, of around 50–60% in seven consecutive batches.
Expression Patterns of Cancer-Testis Antigens in Human Embryonic Stem Cells and Their Cell Derivatives Indicate Lineage Tracks
Authors: Lifantseva Nadya , Koltsova Anna , Krylova Tatyana , Yakovleva Tatyana , Poljanskaya Galina , Gordeeva Olga
Published: August 2011

Pluripotent stem cells can differentiate into various lineages but undergo genetic and epigenetic changes during long-term cultivation and, therefore, require regular monitoring. The expression patterns of cancer-testis antigens (CTAs) MAGE-A2, -A3, -A4, -A6, -A8, -B2, and GAGE were examined in undifferentiated human embryonic stem (hES) cells, their differentiated derivatives, teratocarcinoma (hEC) cells, and cancer cell lines of neuroectodermal and mesodermal origin. Undifferentiated hES cells and embryoid body cells expressed MAGE-A3, -A6, -A4, -A8, and GAGEs while later differentiated derivatives expressed only MAGE-A8 or MAGE-A4. Likewise, mouse pluripotent stem cells also express CTAs of Magea but not Mageb family. Despite similarity of the hES and hEC cell expression patterns, MAGE-A2 and MAGE-B2 were detected only in hEC cells but not in hES cells. Moreover, our analysis has shown that CTAs are aberrantly expressed in cancer cell lines and display low tissue specificity. The identification of CTA expression patterns in pluripotent stem cells and their derivatives may be useful for isolation of abnormally CTA-expressing cells to improve the safety of stem-cell based therapy.
Alcohol Consumption and Risk of All-Cause and Cardiovascular Disease Mortality in Men
Authors: Howie Erin K. , Sui Xuemei , Lee Duck-chul , Hooker Steven P. , Hébert James R. , Blair Steven N.
Published: August 2011

This study examined the association between consumption of alcoholic beverages and all-cause and cardiovascular disease (CVD) mortality in a cohort of men (n=31,367). In the Cox proportional hazards model adjusted for age, year of examination, body mass index (BMI), smoking, family history of CVD, and aerobic fitness, there were no significant differences in risk of all-cause mortality across alcohol intake groups. Risk of CVD mortality was reduced 29% in quartile 1 (HR = 0.71, 95% confidence interval (CI): 0.53, 0.95) and 25% in quartile 2 (HR = 0.75, 95% CI: 0.58, 0.98). The amount of alcohol consumed to achieve this risk reduction was <6 drinks/week; less than the amount currently recommended. The addition of other potential confounders and effect modifiers including blood pressure, insulin sensitivity, lipid levels, and psychological variables did not affect the magnitude of association. Future research is needed to validate the current public health recommendations for alcohol consumption.
Recent Advances in Electrochemical Glycobiosensing
Authors: Sánchez-Pomales Germarie , Zangmeister Rebecca A.
Published: August 2011

Biosensors based on electrochemical transduction mechanisms have recently made advances into the field of glycan analysis. These glyco-biosensors offer simple, rapid, sensitive, and economical approaches to the measurement need for rapid glycan analysis for biomarker detection, cancer and disease diagnostics, and bioprocess monitoring of therapeutic glycoproteins. Although the prevalent methods of glycan analysis (high-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance spectroscopy) provide detailed identification and structural analysis of glycan species, there are significantly few low-cost, rapid glycan assays available for diagnostic and screening applications. Here we review instances in which glyco-biosensors have been used for glycan analysis using a variety of electrochemical transduction mechanisms (e.g., amperometric, potentiometric, impedimetric, and voltammetric), selective binding agents (e.g., lectins and antibodies), and redox species (e.g., enzyme substrates, inorganic, and nanomaterial).
Cancer Multidisciplinary Team Meetings: Evidence, Challenges, and the Role of Clinical Decision Support Technology
Authors: Patkar Vivek , Acosta Dionisio , Davidson Tim , Jones Alison , Fox John , Keshtgar Mohammad
Published: August 2011

Multidisciplinary team (MDT) model in cancer care was introduced and endorsed to ensure that care delivery is consistent with the best available evidence. Over the last few years, regular MDT meetings have become a standard practice in oncology and gained the status of the key decision-making forum for patient management. Despite the fact that cancer MDT meetings are well accepted by clinicians, concerns are raised over the paucity of good-quality evidence on their overall impact. There are also concerns over lack of the appropriate support for this important but overburdened decision-making platform. The growing acceptance by clinical community of the health information technology in recent years has created new opportunities and possibilities of using advanced clinical decision support (CDS) systems to realise full potential of cancer MDT meetings. In this paper, we present targeted summary of the available evidence on the impact of cancer MDT meetings, discuss the reported challenges, and explore the role that a CDS technology could play in addressing some of these challenges.
Evaluation of Transforming Growth Factor Beta-1 Gene 869T/C Polymorphism with Hypertension: A Meta-Analysis
Authors: Niu Wenquan
Published: August 2011

Association between transforming growth factor beta-1 gene (TGFB1) 869T/C polymorphism and hypertension has been widely evaluated, yet with conflicting results. As meta-analysis is a reliable way to resolve discrepancies; I aimed to evaluate this association. Data were available from 9 study populations involving 6151 subjects. Overall, comparison of allele 869C with 869T generated a significant 30% increased hypertension risk (95% confidence interval [95% CI]: 1.11–1.51;P=0.001), which was strengthened for homozygous comparison (869CC versus 869TT) with odds ratio (OR) doubled to 1.62 (95% CI: 1.23–2.14;P=0.001). Stratified analysis by study design demonstrated stronger associations in population-based studies than in hospital-based studies with OR, except in the dominant model, being increased by 7.94–18.61%. Likewise, ethnicity-based analysis exhibited a contradictory association between Asians and Whites. Conclusively, these findings support the notion thatTGFB1gene 869T/C polymorphism may influence the risk of hypertension, especially in Asian populations.
The Relation between Fructose-Induced Metabolic Syndrome and Altered Renal Haemodynamic and Excretory Function in the Rat
Authors: Abdulla Mohammed H. , Sattar Munavvar A. , Johns Edward J.
Published: August 2011

This paper explores the possible relationships between dietary fructose and altered neurohumoral regulation of renal haemodynamic and excretory function in this model of metabolic syndrome. Fructose consumption induces hyperinsulinemia, hypertriglyceridaemia, insulin resistance, and hypertension. The pathogenesis of fructose-induced hypertension is dubious and involves numerous pathways acting both singly and together. In addition, hyperinsulinemia and hypertension contribute significantly to progressive renal disease in fructose-fed rats. Moreover, increased activity of the renin-angiotensin and sympathetic nervous systems leading to downregulation of receptors may be responsible for the blunted vascular sensitivity to angiotensin II and catecholamines, respectively. Various approaches have been suggested to prevent the development of fructose-induced hypertension and/or metabolic alteration. In this paper, we address the role played by the renin-angiotensin and sympathetic nervous systems in the haemodynamic alterations that occur due to prolonged consumption of fructose.
Inflammation in Cardiovascular Tissue Engineering: The Challenge to a Promise: A Minireview
Authors: Simionescu Agneta , Schulte Jason B. , Fercana George , Simionescu Dan T.
Published: August 2011

Tissue engineering employs scaffolds, cells, and stimuli brought together in such a way as to mimic the functional architecture of the target tissue or organ. Exhilarating advances in tissue engineering and regenerative medicine allow us to envisionin vitrocreation orin vivoregeneration of cardiovascular tissues. Such accomplishments have the potential to revolutionize medicine and greatly improve our standard of life. However, enthusiasm has been hampered in recent years because of abnormal reactions at the implant-host interface, including cell proliferation, fibrosis, calcification and degeneration, as compared to the highly desired healing and remodeling. Animal and clinical studies have highlighted uncontrolled chronic inflammation as the main cause of these processes. In this minireview, we present three case studies highlighting the importance of inflammation in tissue engineering heart valves, vascular grafts, and myocardium and propose to focus on the endothelial barrier, the “final frontier” endowed with the natural potential and ability to regulate inflammatory signals.
Use of Nucleic Acid Analogs for the Study of Nucleic Acid Interactions
Authors: Nakano Shu-ichi , Fujii Masayuki , Sugimoto Naoki
Published: August 2011

Unnatural nucleosides have been explored to expand the properties and the applications of oligonucleotides. This paper briefly summarizes nucleic acid analogs in which the base is modified or replaced by an unnatural stacking group for the study of nucleic acid interactions. We also describe the nucleoside analogs of a base pair-mimic structure that we have examined. Although the base pair-mimic nucleosides possess a simplified stacking moiety of a phenyl or naphthyl group, they can be used as a structural analog of Watson-Crick base pairs. Remarkably, they can adopt two different conformations responding to their interaction energies, and one of them is the stacking conformation of the nonpolar aromatic group causing the site-selective flipping of the opposite base in a DNA double helix. The base pair-mimic nucleosides can be used to study the mechanism responsible for the base stacking and the flipping of bases out of a nucleic acid duplex.
Global terrestrial isoprene emission models: sensitivity to variability in climate and vegetation
Authors: Arneth A. , Schurgers G. , Lathiere J. , Duhl T. , Beerling D. J. , Hewitt C. N. , Martin M. , Guenther A.
Published: August 2011

Abstract. Due to its effects on the atmospheric lifetime of methane, the burdens of tropospheric ozone and growth of secondary organic aerosol, isoprene is central among the biogenic compounds that need to be taken into account for assessment of anthropogenic air pollution-climate change interactions. Lack of process-understanding regarding leaf isoprene production as well as of suitable observations to constrain and evaluate regional or global simulation results add large uncertainties to past, present and future emissions estimates. Focusing on contemporary climate conditions, we compare three global isoprene models that differ in their representation of vegetation and isoprene emission algorithm. We specifically aim to investigate the between- and within model variation that is introduced by varying some of the models' main features, and to determine which spatial and/or temporal features are robust between models and different experimental set-ups. In their individual standard configurations, the models broadly agree with respect to the chief isoprene sources and emission seasonality, with maximum monthly emission rates around 20–25 Tg C, when averaged by 30-degree latitudinal bands. They also indicate relatively small (approximately 5 to 10 % around the mean) interannual variability of total global emissions. The models are sensitive to changes in one or more of their main model components and drivers (e.g., underlying vegetation fields, climate input) which can yield increases or decreases in total annual emissions of cumulatively by more than 30 %. Varying drivers also strongly alters the seasonal emission pattern. The variable response needs to be interpreted in view of the vegetation emission capacities, as well as diverging absolute and regional distribution of light, radiation and temperature, but the direction of the simulated emission changes was not as uniform as anticipated. Our results highlight the need for modellers to evaluate their implementations of isoprene emission models carefully when performing simulations that use non-standard emission model configurations.
The effects of a solar eclipse on photo-oxidants in different areas of China
Authors: Wu J.-B. , Wang Z. F. , Zhang W. , Dong H. B. , Pan X. L. , Li J. , Lin C.-Y. , Xie P. H.
Published: August 2011

Abstract. This study investigates the effects of the total solar eclipse of 22 July 2009 on surface ozone and other photo-oxidants over China. A box model was used to study the sensitivity of ozone to the limb darkening effect during an eclipse event, and to show that the impact on ozone is small (less than 0.5 %). In addition, the regional model WRF-Chem was applied to study the effects of the eclipse on meteorological and chemical parameters, focusing on different regions in China. Chemical and meteorological observations were used to validate the model and to show that it can capture the effects of the total solar eclipse well. Model calculations show distinct differences in the spatial distributions of meteorological and chemical parameters with and without the eclipse. The maximum impacts of the eclipse occur over the area of totality, where there is a decrease in surface temperature of 1.5 °C and decrease in wind speed of 1 m s−1. The maximum impacts on atmospheric pollutants occur over parts of north and east China where emissions are greater, with an increase of 5 ppbv in NO2 and 25 ppbv in CO and a decrease of 10 ppbv in O3 and 4 ppbv in NO. This study also demonstrates the effects of the solar eclipse on surface photo-oxidants in different parts of China. Although the sun was obscured to a smaller extent in polluted areas than in clean areas, the impacts of the eclipse in polluted areas are greater and last longer than they do in clean areas. In contrast, the change in radical concentrations (OH, HO2 and NO3) in clean areas is much larger than in polluted areas mainly because of the limited source of radicals in these areas. The change in radical concentrations during the eclipse reveals that nighttime chemistry dominates in both clean and polluted areas. As solar eclipses provide a natural opportunity to test more thoroughly our understanding of atmospheric chemistry, especially that governed by photolysis, a comprehensive experimental campaign during a future solar eclipse is highly desirable.
Individual particle analysis of aerosols collected under haze and non-haze conditions at a high-elevation mountain site in the North China plain
Authors: Li W. J. , Zhang D. Z. , Shao L. Y. , Zhou S. Z. , Wang W. X.
Published: August 2011

Abstract. The North China plain is a region with megacities and huge populations. Aerosols over the highly polluted area have a significant impact on a regional and global climate. In order to investigate the physical and chemical characteristics of aerosol particles in elevated layers there, observations were carried out at the summit of Mt. Tai (1534 m a.s.l) from 19 to 28 April 2010, when the air masses were advected from the east (phase-I: 19–21 April), from the south (phase-II: 22–25 April), and from the northwest (phase-III: 26–28 April). Individual aerosol particles were identified with transmission electron microscopy (TEM), new particle formation (NPF) and growth events were monitored by a wide-range particle spectrometer, and ion concentrations in PM2.5 were analyzed. During phase-I and phase-II, haze layers caused by anthropogenic pollution were observed, and a major number of particles were sulfur-rich (47–49 %). In phase-III, haze disappeared due to the intrusion of cold air from the northwest, and mineral dust particles from deserts were predominant (43 %). NPF followed by particle growth during daytime was more pronounced at upper levels of the haze layers than clear days. Particle growth during daytime resulted in an increase of particle geometric mean diameter from 10–22 nm in the morning to 56–96 nm in the evening. TEM analysis suggests that sulfuric acid and secondary organic compounds should be important factors for particle nucleation and growth. Moreover, the presence of ultrafine and fine anthropogenic particles (e.g., soot, metal, and fly ash) embedded within S-rich particles may indicate their influences on particle nucleation through condensation and enhancement of particle growth through coagulation. Each fine refractory particle can enlarge the sulfate particles by 10–20 nm. Abundant mineral particles in phase-III likely suppressed the NPF processes because a high number of crustal mineral particles in the free troposphere supplied an important surface on which acidic gases or acids condensed.
The influence of eruption season on the global aerosol evolution and radiative impact of tropical volcanic eruptions
Authors: Toohey M. , Krüger K. , Niemeier U. , Timmreck C.
Published: August 2011

Abstract. Simulations of tropical volcanic eruptions using a general circulation model with coupled aerosol microphysics are used to assess the influence of season of eruption on the aerosol evolution and radiative impacts at the Earth's surface. This analysis is presented for eruptions with SO2 injection magnitudes of 17 and 700 Tg, the former consistent with estimates of the 1991 Mt. Pinatubo eruption, the later a near-"super eruption". For each eruption magnitude, simulations are performed with eruptions at 15° N, at four equally spaced times of year, and sensitivity to eruption season is quantified as the difference between the maximum and minimum cumulative anomalies. Eruption season has a significant influence on aerosol optical depth (AOD) and clear-sky shortwave (SW) radiative flux anomalies for both eruption magnitudes. The sensitivity to eruption season for both fields is generally weak in the tropics, but increases in the mid- and high latitudes, reaching maximum values of ~80 %. Global mean AOD and clear-sky SW anomalies show sensitivity to eruption season on the order of 15–20 %, which results from differences in aerosol effective radius for the different eruption seasons. Smallest aerosol size and largest cumulative impact result from a January eruption for the Pinatubo-magnitude, and from a July eruption for the near-super eruption. In contrast to AOD and clear-sky SW anomalies, all-sky SW anomalies are found to be insensitive to season of eruption for the Pinatubo-magnitude eruption experiment, due to the reflection of solar radiation by clouds in the mid- to high latitudes. However, differences in all-sky SW anomalies between eruptions in different seasons are significant for the larger eruption magnitude, and the ~15 % sensitivity to eruption season of the global mean all-sky SW anomalies is comparable to the sensitivity of global mean AOD and clear-sky SW anomalies. Our estimates of sensitivity to eruption season are larger than previously reported estimates: implications regarding volcanic AOD timeseries reconstructions and their use in climate models are discussed.
Characterization of the bio-optical anomaly and diurnal variability of the particulate matter, as seen from the scattering and backscattering coefficients, in ultra-oligotrophic eddies of the Mediterranean Sea
Authors: Loisel H. , Vantrepotte V. , Norkvist K. , Mériaux X. , Kheireddine M. , Ras J. , Pujo-Pay M. , Combet Y. , Leblanc K. , Mauriac R. , Dessailly D. , Moutin T.
Published: August 2011

Abstract. The variability of the inherent optical properties is investigated in the ultra-oligotrophic waters of the Mediterranean Sea sampled during the BOUM experiment performed during the early summer 2008. Bio-optical relationships found for the ultra-oligotrophic waters of the three anticyclonic gyres sampled significantly depart from the mean standard relationships provided for the global ocean, confirming the particular character of these Mediterranean waters. These optical anomalies are diversely related to the specific biological and environmental conditions occurring in the studied ecosystem. Specifically, the surface specific phytoplankton absorption coefficient exhibits values lower than those expected from the general relationships mainly in relation with a high contribution of relatively large sized phytoplankton. Conversely, the particulate backscattering coefficient, bbp, values are much higher than the mean standard values for a given chlorophyll-a concentration, TChl-a. This feature can presumably be related to the relevant influence of highly refractive submicrometer particles of Saharan origin in the surface layer of the water column. The present measurements also show that the Mediterranean Sea is greener than TChl-a alone indicates, as already stressed in previous studies. This color anomaly is partly explained by the estimated colored dissolved organic matter and submicrometer particles absorption coefficients, and to a greater extent by the high bbp/TChl-a values assuming that these particles backscatter light similarly in the green and blue parts of the visible spectrum. The diel variation of both the particulate matter attenuation and backscattering coefficients were also investigated specifically. Despite some differences in the timing and the magnitude of the daily oscillations found for these optical parameters, potential for the backscattering coefficient daily oscillation to be used, similarly to that for the attenuation coefficient, as a proxy for estimating carbon community production budget has been highlighted for the first time. This result is particularly relevant for present and future geostationary spatial ocean color missions.
Redox sensitive elements in foraminifera from the Peruvian oxygen minimum zone
Authors: Glock N. , Eisenhauer A. , Liebetrau V. , Wiedenbeck M. , Hensen C. , Nehrke G.
Published: August 2011

Abstract. Testing order to assess their potential as a proxy for redox conditions the element/Ca ratios of the redox sensitive elements Mn and Fe were determined in tests of benthic foraminifera from the Peruvian oxygen minimum zone (OMZ). Prior to the determination of the element/Ca ratios the distributions of Ca, Mn, Fe, Mg, Ba, Al, Si, P and S in tests of the shallow infaunal species Uvigerina peregrina and Bolivina spissa were mapped with an electron microprobe (EMP). An Fe rich phase which is also enriched in Al, Si, P and S was found on the inner test surface of U. peregrina. The element distributions of a specimen treated with an oxidative cleaning procedure show the absence of this phase. EMP maps of B. spissa also identified a similar phase which too could be removed with oxidative cleaning. Neither in B. spissa nor in U. peregrina were any hints for diagenetic (oxyhydr)oxide or carbonate coatings found. Mn/Ca and Fe/Ca ratios of single specimens of B. spissa from different locations have been determined by secondary ion mass spectrometry (SIMS). Bulk analyses using solution ICP-MS of several samples were compared to the SIMS data. The difference between SIMS analyses on single specimens and ICP-MS bulk analyses from the same sampling sites was 14.0–134.8 μmol mol−1 for the Fe/Ca and 1.68 μmol mol−1 for the Mn/Ca ratios. This amounts to 3–29 % for the Fe/Ca and 21.5 % for the Mn/Ca ratios of the overall variability between the samples of the different sampling sites. The Mn/Ca ratios in the calcite were generally relatively low (2.21–9.93 μmol mol−1) but of the same magnitude as in the pore waters (1.37–6.67 μmol mol−1). Comparison with sediment pore water data showed that Mn/Ca in the foraminiferal calcite is proportional to the Mn/Ca ratio in the top cm of the pore water. The lowest Fe/Ca ratio in tests of B. spissa (87.0 μmol mol−1) has been found at a sampling site which was strongly depleted in oxygen and showed a high, sharp iron peak in the top interval of the pore water. This, and the fact that at this location many dead but no living specimens were found during sampling time, hints that the specimens already were dead before the Fe flux started and the sampling site just recently turned anoxic due to fluctuations of the lower boundary of the OMZ where the sampling site is located (465 m water depth).
What can we learn from long-term groundwater data to improve climate change impact studies?
Authors: Stoll S. , Hendricks Franssen H. J. , Barthel R. , Kinzelbach W.
Published: August 2011

Abstract. Future risks for groundwater resources, due to global change are usually analyzed by driving hydrological models with the outputs of climate models. However, this model chain is subject to considerable uncertainties. Given the high uncertainties it is essential to identify the processes governing the groundwater dynamics, as these processes are likely to affect groundwater resources in the future, too. Information about the dominant mechanisms can be achieved by the analysis of long-term data, which are assumed to provide insight in the reaction of groundwater resources to changing conditions (weather, land use, water demand). Referring to this, a dataset of 30 long-term time series of precipitation dominated groundwater systems in northern Switzerland and southern Germany is collected. In order to receive additional information the analysis of the data is carried out together with hydrological model simulations. High spatio-temporal correlations, even over large distances could be detected and are assumed to be related to large-scale atmospheric circulation patterns. As a result it is suggested to prefer innovative weather-type-based downscaling methods to other stochastic downscaling approaches. In addition, with the help of a qualitative procedure to distinguish between meteorological and anthropogenic causes it was possible to identify processes which dominated the groundwater dynamics in the past. It could be shown that besides the meteorological conditions, land use changes, pumping activity and feedback mechanisms governed the groundwater dynamics. Based on these findings, recommendations to improve climate change impact studies are suggested.
Early Cuff Anchorage for Tunneled Central Venous Catheters using a Buried Absorbable Suture
Authors: Ramsey Christopher , McClure Hamish , Bhambra Bali , Dolling Sarah , Bodenham Andrew
Published: August 2011

Purpose

Long-term tunneled cuffed central venous catheters (CVC) are widely used for the administration of chemotherapy, parenteral nutrition, and fluids. External migration and displacement of catheters have been reported to occur in 2.4% to 24% of cases, prompting the development of various anchoring strategies. We report an adaptation of previous techniques, where the cuff of a tunneled catheter is prevented from moving outwards by inserting a buried absorbable purse string suture around the catheter. Its effectiveness in catheter fixation has been assessed in a prospective audit.

Methods

The effectiveness of the anchoring suture was assessed in a cohort of 101 oncology chemotherapy patients using specific measurements of catheter movement (Dacron cuff to suture distance, Dacron cuff to exit site distance, and external catheter length), taken at catheter insertion and removal.

Results

Catheters were placed in situ for a median of 16 weeks. Displacement was found in 19% to 36% of lines (depending on the specific measurement taken), with a median cuff to exit site movement of 7.5 mm (range 5 to 40 mm) and a median length of external line movement of 10 mm (range 5 to 70 mm). The suture had good cosmetic results.

Conclusions

This is, to our knowledge, the first study to attempt to quantify CVC movement. Our data suggest that this suture technique provides an effective and safe additional strategy for cuffed tunneled CVC fixation.
On a Class of PDE Involving
p-Biharmonic Operator
Authors: El Khalil Abdelouahed
Published: August 2011

The existence of solution for a fourth-order nonlinear partial differential equation (PDE) class involving p-biharmonic operator Δ(|Δu|p−2Δu)=λρ(x)|u|q−2u  in  Ω,  u=Δu=0,  on⁡  ∂Ω, is proved by applying mountain pass theorem and a local minimization.
Esophageal Stenting in the Setting of Malignancy
Authors: Martinez Juan Carlos , Puc Matthew M. , Quiros Roderick M.
Published: August 2011

Esophageal cancer is often diagnosed at an advanced stage, with many patients found to have locoregional or metastatic disease at time of diagnosis. Because of this, cure may be unlikely, leading treatment efforts to focus more on symptom palliation and improving patient quality of life. The majority of patients with advanced disease suffer from some degree of dysphagia. Palliative efforts are therefore directed at relieving dysphagia, allowing patients to manage their oropharyngeal secretions, reduce aspiration risk, and maintain caloric intake orally. A variety of endoscopic treatment modalities have been utilized with these objectives in mind, with options determined by the location and size of the tumor, as well as the patient's expected prognosis. In this article, we review the use of endoscopically-placed stents for palliation in patients with advanced esophageal cancer. We discuss the history of stent use in such cases, as well as more recent developments in stent technology. We give an overview of some of the more commonly used stents in practice, discuss the technique of insertion, and survey the short- and long-term outcomes of stent placement.
Treatment and secondary prevention of venous thrombo -embolism in cancer patients
Authors: Pabinger I. , Ay C.
Published: August 2011

Cancer is a major and independent risk factor of venous thromboembolism (VTE). In clinical practice, a high number of VTE events occurs in patients with cancer, and treatment of cancer-associated VTE differs in several aspects from treatment of VTE in the general population. However, treatment in cancer patients remains a major challenge, as the risk of recurrence of VTE as well as the risk of major bleeding during anticoagulation is substantially higher in patients with cancer than in those without cancer. In several clinical trials, different anticoagulants and regimens have been investigated for treatment of acute VTE and secondary prophylaxis in cancer patients to prevent recurrence. Based on the results of these trials, anticoagulant therapy with low-molecular-weight heparins (LMWH) has become the treatment of choice in cancer patients with acute VTE in the initial period and for extended and long-term anticoagulation for 3–6 months. New oral anti-coagulants directly inhibiting thrombin or factor Xa, have been developed in the past decade and studied in large phase III clinical trials. Results from currently completed trials are promising and indicate their potential use for treatment of VTE also in cancer patients. However, the role of the new oral thrombin and factor Xa inhibitors for VTE treatment in cancer patients still has to be clarified in further studies specifically focusing on cancer-associated VTE. This brief review will summarize the current strategies of initial and long-term VTE treatment in patients with cancer and discuss the potential use of the new oral anticoagulants.
Thermosetting resin compositions based on novolac and modified novolac
Authors: Mustata Fanica
Published: August 2011

Novel formaldehyde novolac resins at various molar ratios of monomers (4,4′‐methylenedianiline/p‐nonylphenol/p‐formaldehyde) were synthesized in the presence of an acid catalyst. The obtained resins were characterized by using elemental analysis, FT IR, and 1H NMR spectroscopic methods. Subsequently, these resins may further be modified by allylation and methacrylation and may be used as cross‐linking agents for epoxy resin/bismaleimide resin formulations. The curing of epoxy and bismaleimide resins with formaldehyde resins (FR) and modified FR and the thermal decomposition behavior of cross‐linked resins were studied by differential scanning calorimetry (DSC) and thermogravimetric (TGA) techniques. DSC scans for the curing of epoxy resins with FR show a single exothermic peak, which implied only the occurrence of cure reactions between epoxy ring and amine protons, whereas the DSC scans for the epoxy resins, bismaleimide resins, and modified FR systems have two exothermic peaks. The cured products possess a good thermal stability and low water absorption. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 30: 219–233, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20218
Postural strategies employed by orangutans (Pongo abelii) during feeding in the terminal branch niche
Authors: Myatt J.P. , Thorpe S.K.S.
Published: August 2011

Obtaining food in an arboreal habitat is complex due to the irregular and flexible nature of the supports available. As the largest predominantly arboreal primate, orangutans are expected to have developed particular postural strategies to enable them to feed successfully. In particular, they need to be able to cope within the terminal branch niche (TBN) as this is where the smallest, most compliant supports are, and also where the majority of the fruit and leaves are situated. We recorded feeding posture, along with a number of ecological and behavioral variables from different age‐sex classes to enable analysis of the interactions between these and the compliance of the supports (as estimated from stiffness score). Suspensory postures with a pronograde orientation were used on the most compliant supports for all age‐sex classes and appeared to play a particular role in facilitating safe use of the TBN by distributing body weight and using limbs for balance across multiple supports. This contradicts the idea that orthograde suspension evolved in response to the demands of feeding in the TBN. Adult males appear to use the same postures and feeding zones as the other age‐sex classes, but appear to use stiffer supports where possible due to their larger body mass. Feeding method differed between the age‐sex classes in relation to support stiffness, with larger adult males taking fewer risks due to their larger size, compared to infants and juveniles. Am J Phys Anthropol, 2011. © 2011 Wiley‐Liss, Inc.
Removal of heavy metals from model wastewater by using carboxymehyl cellulose/2‐acrylamido‐2‐methyl propane sulfonic acid hydrogels
Authors: El‐Hag Ali Amr
Published: August 2011

A series of functional copolymer hydrogels composed of carboxymethyl cellulose (CMC) and 2‐acrylamido‐2‐methyl propane sulfonic acid (AMPS) were synthesized using γ‐radiations‐induced copolymerization and crosslinking. Preparation conditions were optimized, and the swelling characteristics were investigated. The ability of the prepared hydrogels to recover some toxic metal ions from their aqueous solutions was studied. The prepared hydrogel showed a great capability to recover metal ions such as: Mn+2, Co+2, Cu+2, and Fe+3 from their solutions. The data revealed that the chelating ability of the prepared hydrogels is mainly dependent on their internal composition, in addition to the physical properties of the metal ion solution such as pH and metal ion concentration. The data show that the chelating ability of the prepared hydrogels increases by increasing the AMPS content in the hydrogel as well as the increment in the pH of the solution and the metal ion concentration. The prepared CMC/AMPS copolymer hydrogels are chemically stable enough to be reused for at least five times with the same efficiency. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of epoxidized natural rubber on thermal properties, fatigue life, and natural weathering test of styrene butadiene rubber/recycled acrylonitrile‐butadiene rubber (SBR/NBRr) blends
Authors: Noriman Nik Zulkepli , Ismail Hanafi
Published: August 2011

The utilization of waste rubber powder in polymer matrices provides an attractive strategy for polymer waste disposal. Addition of recycled acrylonitrile‐butadiene rubber (NBRr) in rubber compounds gives economic (lowering the cost of rubber compounds) as well as processing advantages. In this study, the properties of styrene butadiene rubber (SBR)/NBRr blends with and without epoxidized natural rubber (ENR‐50) as a compatibilizer were determined. The results such as thermal gravimetric analysis (TGA), fatigue life, and natural weathering test of SBR/NBRr blends with and without ENR‐50 were carried out. Results showed that TG thermograms of SBR/NBRr blends with ENR‐50 show lower thermal stability compared blends without ENR‐50. The incorporation of ENR‐50 into SBR/NBRr blends has reduced char residue compared SBR/NBRr blends without ENR‐50. The incorporation of ENR‐50 in SBR/NBRr blends has increased the rigidity of the blends thus lowering the fatigue life. The increment in tensile properties retention of SBR/NBRr blends with ENR‐50 indicated the enhancement on weathering resistant. The surfaces of SBR/NBRr blends with ENR‐50 after 6 months exposure showed a minimal severity of crack compared with SBR/NBRr blends without ENR‐50. It revealed that the scale of cracks has reduced indicating well‐retaining interfacial adhesion between SBR and NBRr with the presence of ENR‐50 as a compatibilizer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
High‐Speed Carbon Nanotube Actuators Based on an Oxidation/Reduction Reaction
Authors: Mukai Ken , Asaka Kinji , Hata Kenji , Fernández Otero Toribio , Oike Hideaki
Published: August 2011

Actuators with a high‐speed response under a high‐frequency (more than 100 Hz) applied square‐wave voltage of ±2 V have been developed with an electrode composed of millimeter‐long single‐walled carbon nanotubes synthesized by the “supergrowth method” (SG‐SWNTs) and ionic liquids (ILs). Detailed studies concerning induced electric current and transferred charge in the electrode as well as cyclic voltammetric studies of the electrode revealed that the high‐speed response originates from the electric current generated by an oxidation/reduction (redox) reaction in addition to electric double‐layer charging. The contribution of the redox reactions of SG‐SWNTs to the actuation is sensitive to the presence of supporting polymers, the thickness of the electrolyte, and the amplitude of the applied voltage.
Microwave‐Assisted Partial Hydrogenation of Citral by using Ionic Liquid‐Coated Porous Glass Catalysts
Authors: Gallert Thomas , Hahn Martin , Sellin Martin , Schmöger Christine , Stolle Achim , Ondruschka Bernd , Keller Thomas F. , Jandt Klaus D.
Published: August 2011

The microwave‐assisted hydrogenation of citral (3,7‐dimethylocta‐2,6‐dienal) to citronellal with molecular hydrogen as the reducing agent was investigated. Several polar and non‐polar solvents were screened and imidazolium‐based ionic liquids were applied as modifiers for the palladium‐containing porous glass catalysts (Pd/TP). The best results were obtained with N‐ethyl‐N’‐methylimidazolium dicyanamide, N‐ethyl‐N’‐methylimidazolium acetate, or N‐ethyl‐N’‐methylimidazolium trifluoroacetate, which were used to prepare supported catalysts with an ionic liquid layer (SCILL) on Pd/TP by wet‐impregnation. The influence of pressure and temperature when using these ionic liquid‐containing catalysts, as well as their long‐term stabilities, were examined. Working with microwave‐assisted heating, high yields of citronellal were achieved under mild conditions within short reaction times. Catalyst characterization was carried out by means of BET measurements, X‐ray photoelectron spectroscopy (XPS) and thermo‐gravimetric analyses. The influences of the ionic liquid layer were derived from experiments carried out before and after the reactions.
Dielectrophoretic particle–particle interaction under AC electrohydrodynamic flow conditions
Authors: Lee Doh‐Hyoung , Yu Chengjie , Papazoglou Elisabeth , Farouk Bakhtier , Noh Hongseok M.
Published: August 2011

We used the Maxwell stress tensor method to understand dielectrophoretic particle–particle interactions and applied the results to the interpretation of particle behaviors under alternating current (AC) electrohydrodynamic conditions such as AC electroosmosis (ACEO) and electrothermal flow (ETF). Distinct particle behaviors were observed under ACEO and ETF. Diverse particle–particle interactions observed in experiments such as particle clustering, particles keeping a certain distance from each other, chain and disc formation and their rotation, are explained based on the numerical simulation data. The improved understanding of particle behaviors in AC electrohydrodynamic flows presented here will enable researchers to design better particle manipulation strategies for lab‐on‐a‐chip applications.