bluuebunny/crossref_metadata_2025 huggingface dataset:
Benchmarking the SPARC software program for estimating solubilities of naphthalene and anthracene in organic solvents
Authors: Rayne Sierra , Forest Kaya
Published: November 2011

The SPARC software program was benchmarked for calculating the solubilities of two representative polyaromatic hydrocarbons (PAHs), naphthalene and anthracene, in a range of organic solvents at various temperatures. Although SPARC was able to reasonably approximate the solubilities of naphthalene in some organic solvents, gross errors were obtained for other solvents. For anthracene, poor prediction performance was observed in all solvents considered. Overall, the results suggest that SPARC is currently not suitable for accurately predicting the solubilities of representative PAHs relevant for the petroleum sector in various organic solvents.
21 Tesla Rat Heart Magnetic Resonance Microimaging by Paramagnetic Anti-Troponin Bound Polyethylene Based Iron-Oxide Nanoparticles and Image Processing
Authors: Sharma Rakesh
Published: November 2011

21T MR microimaging with the first use of troponin nanoparticles enhances the visualization of cardiac muscle fibers and offers technical advancement for the future. Diffusion weighting offers fiber tracking and functional analysis. Image processing offers heart probabilistic atlas and maps.http://www.ismrm.org/10/program/ELECTRONICPOSTERS.htm
Tinnitus and Its Effect on Working Memory and Attention
Authors: Rossiter Susan , Stevens Catherine , Walker Gary
Published: November 2011

Purpose

In 2 experiments, the assumption that continual orienting to tinnitus uses cognitive resources was investigated. It was hypothesized that differences in performance of tinnitus and control groups would manifest during demanding or unfamiliar tasks that required strategic, controlled processing and that reduced performance was not related solely to levels of anxiety.

Method

Nineteen participants with chronic, moderate tinnitus—matched with a control group for age, education, and verbal IQ—completed auditory verbal working-memory and visual divided-attention tasks, with task order counterbalanced across participants.

Results

As hypothesized, reading span of the tinnitus group was significantly shorter than that of the control group (Task 1). In Task 2, the tinnitus group recorded slower reaction times and poorer accuracy in the most demanding dual task context. Covariate analyses revealed that differences in task performance were not attributable to anxiety scale scores.

Conclusions

Complaints of the distracting effects of tinnitus have a basis in performance test outcomes. Future research should investigate effects of severe tinnitus and possible effects of hearing loss. At the level of theory development, results from this study suggest that tinnitus affects cognition to the extent that it reduces cognitive capacity needed to perform tasks that require voluntary, conscious, effortful, and strategic control.
Consistent Air Flow to the Face Facilitates Vection
Authors: Seno Takeharu , Ogawa Masaki , Ito Hiroyuki , Sunaga Shoji
Published: November 2011

We examined whether a somatosensory cue suggesting forward self-motion facilitated vection. We provided a consistent air flow to subjects' faces by using an electric fan. Vection strength was increased when the air flow was provided.
Challenges of sulfur SAD phasing as a routine method in macromolecular crystallography
Authors: Doutch James , Hough Michael A. , Hasnain S. Samar , Strange Richard W.
Published: November 2011

The sulfur SAD phasing method allows the determination of protein structuresde novowithout reference to derivatives such as Se-methionine. The feasibility for routine automated sulfur SAD phasing using a number of current protein crystallography beamlines at several synchrotrons was examined using crystals of trimericAchromobacter cycloclastesnitrite reductase (AcNiR), which contains a near average proportion of sulfur-containing residues and two Cu atoms per subunit. Experiments using X-ray wavelengths in the range 1.9–2.4 Å show that we are not yet at the level where sulfur SAD is routinely successful forautomatedstructure solution and model building using existing beamlines and current software tools. On the other hand, experiments using the shortest X-ray wavelengths available on existing beamlines could be routinely exploited to solve and produce unbiased structural models using the similarly weak anomalous scattering signals from the intrinsic metal atoms in proteins. The comparison of long-wavelength phasing (the Bijvoet ratio for nine S atoms and two Cu atoms is ∼1.25% at ∼2 Å) and copper phasing (the Bijvoet ratio for two Cu atoms is 0.81% at ∼0.75 Å) forAcNiR suggests that lower data multiplicity than is currently required for success should in general be possible for sulfur phasing if appropriate improvements to beamlines and data collection strategies can be implemented.
Dopaminergic enhancement of local food‐seeking is under global homeostatic control
Authors: Beeler Jeff A. , Frazier Cristianne R. M. , Zhuang Xiaoxi
Published: November 2011

Recent work has implicated dopaminergic mechanisms in overeating and obesity with some researchers suggesting parallels between the dopamine dysregulation associated with addiction and an analogous dysregulation in obesity. The precise role of dopamine in mediating reward and reinforcement, however, remains controversial. In contrast to drugs of abuse, pursuit of a natural reward, such as food, is regulated by homeostatic processes that putatively maintain a stable energy balance keeping unrestrained consumption and reward pursuit in check. Understanding how the reward system is constrained by or escapes homeostatic regulation is a critical question. The widespread use of food restriction to motivate animal subjects in behavior paradigms precludes investigation of this relationship as the homeostatic system is locked into deficit mode. In the present study, we examined the role of dopamine in modulating adaptive feeding behavior in semi‐naturalistic homecage paradigms where mice earn all of their food from lever pressing. We compared consumption and meal patterning between hyperdopaminergic dopamine transporter knock‐down and wild‐type mice in two paradigms that introduce escalating costs for procuring food. We found that hyperdopaminergic mice exhibited similar demand elasticity, weight loss and energy balance in response to cost. However, the dopamine transporter knock‐down mice showed clear differences in meal patterning. Consistent with expectations of enhanced motivation, elevated dopamine increased the meal size and reduced intrameal cost sensitivity. Nonetheless, this did not alter the overall energy balance. We conclude that elevated dopamine enhances the incentive or willingness to work locally within meals without shifting the energy balance, enhancing global food‐seeking or generating an energy surplus.
Effects of earnings management on bank cost of debt
Authors: Shen Chung‐Hua , Huang Yu‐Li
Published: November 2011

This study investigates how earnings management influences credit ratings, and thus the cost of debt, using bank data from 85 countries. Using cross‐country data also facilitates the investigation of how information asymmetry affects the influence of earnings management on ratings. The results indicate that raters downgrade ratings when they perceive earnings management, after controlling for other potential determinants of bank credit ratings, implying that earnings management increases borrowing costs. The negative effect of earnings management is mitigated for banks in countries with more extensive and effective banking regulations owing to lower information asymmetry, but aggravated in counties with less robust banking regulations.
Does change in IUCN status affect demand for African bovid trophies?
Authors: Prescott G. W. , Johnson P. J. , Loveridge A. J. , Macdonald D. W.
Published: November 2011

There may be conditions under which trophy hunting can contribute to the conservation of wildlife, but there are cases where its sustainability has been questioned. Several studies have shown that humans place value on rarity, and this may fuel the exploitation of rare species and increase their risk of extinction – a process termed the anthropogenic Allee effect. Previous studies have shown that some rarer species may command higher trophy prices than do broadly similar but less rare ones. Increase in rarity (as measured by International Union for the Conservation of Nature (IUCN) status)) has also been linked to increases in demand as reflected in the volume of recorded trophy hunts. We hypothesized that change in rarity, as measured by change in IUCN status between 2004 and 2010, would have an effect on price if increased demand resulted from the change. Change in rarity was an important predictor of changes in price between 2004 and 2010. Bovids that became more threatened had larger increases in trophy prices than those that did not. Whether this has positive or negative implications for conservation may depend on how well managed the trophy quota setting systems are.
Proteolytic processing of Alzheimer’s β‐amyloid precursor protein
Authors: Zhang Han , Ma Qilin , Zhang Yun‐wu , Xu Huaxi
Published: November 2011

J. Neurochem. (2012) 120 (Suppl. 1), 9–21.

β‐Amyloid precursor protein (APP) is a critical factor in the pathogenesis of Alzheimer’s disease (AD). APP undergoes post‐translational proteolysis/processing to generate the hydrophobic β‐amyloid (Aβ) peptides. Deposition of Aβ in the brain, forming oligomeric Aβ and plaques, is identified as one of the key pathological hallmarks of AD. The processing of APP to generate Aβ is executed by β‐ and γ‐secretase and is highly regulated. Aβ toxicity can lead to synaptic dysfunction, neuronal cell death, impaired learning/memory and abnormal behaviors in AD models in vitro and in vivo. Aside from Aβ, proteolytic cleavages of APP can also give rise to the APP intracellular domain, reportedly involved in multiple types of cellular events such as gene transcription and apoptotic cell death. In addition to amyloidogenic processing, APP can also be cleaved by α‐secretase to form a soluble or secreted APP ectodomain (sAPP‐α) that has been shown to be mostly neuro‐protective. In this review, we describe the mechanisms involved in APP metabolism and the likely functions of its various proteolytic products to give a better understanding of the patho/physiological functions of APP.
Accounting for spatial autocorrelation in null models of tree species association
Authors: Fuller Michael M. , Enquist Brian J.
Published: November 2011

A commonly used null model for species association among forest trees is a well‐mixed community (WMC). A WMC represents a non‐spatial, or spatially implicit, model, in which species form nearest‐neighbor pairs at a rate equal to the product of their community proportions. WMC models assume that the outcome of random dispersal and demographic processes is complete spatial randomness (CSR) in the species’ spatial distributions. Yet, stochastic dispersal processes often lead to spatial autocorrelation (SAC) in tree species densities, giving rise to clustering, segregation, and other nonrandom patterns. Although methods exist to account for SAC in spatially‐explicit models, its impact on non‐spatial models often remains unaccounted for. To investigate the potential for SAC to bias tests based upon non‐spatial models, we developed a spatially‐heterogeneous (SH) modelling approach that incorporates measured levels of SAC. Using the mapped locations of individuals in a tropical tree community, we tested the hypothesis that the identity of nearest‐neighbors represents a random draw from neighborhood species pools. Correlograms of Moran's I confirmed that, for 50 of 51 dominant species, stem density was significantly autocorrelated over distances ranging from 50 to 200 m. The observed patterns of SAC were consistent with dispersal limitation, with most species occurring in distinct patches. For nearly all of the 106 species in the community, the frequency of pairwise association was statistically indistinguishable from that projected by the null models. However, model comparisons revealed that non‐spatial models more strongly underestimated observed species‐pair frequencies, particularly for conspecific pairs. Overall, the CSR models projected more significant facilitative interactions than did SH models, yielding a more liberal test of niche differences. Our results underscore the importance of accounting for stochastic spatial processes in tests of association, regardless of whether spatial or non‐spatial models are employed.
Change in community phylogenetic structure during tropical forest succession: evidence from New Guinea
Authors: Whitfeld T. J. S. , Kress W. J. , Erickson D. L. , Weiblen G. D.
Published: November 2011

Ecologists have recently interpreted patterns of phylogenetic distance among coexisting species as indicative of processes affecting community assembly during forest succession. We investigated plant community phylogenetic structure along a successional gradient in New Guinean lowland rain forest. We surveyed all trees with diameter at breast height ≥ 5 cm in nineteen 0.25 ha plots representing younger secondary, older secondary, and primary forest. We estimated plant community phylogeny from rbcL gene sequences to quantify change in phylogenetic structure during succession. Mean phylogenetic distance among co‐occurring trees increased with total basal area per plot, a proxy for forest age. Significant phylogenetic clustering was detected in secondary forest whereas primary forest was significantly over‐dispersed relative to null expectations. We examined the sensitivity of these patterns to various methods of branch length estimation and phylogenetic uncertainty. Power to detect community phylogenetic patterns when equal branch lengths were assumed was weak in comparison to direct molecular and time‐calibrated measures of divergence. Inferred change during forest succession was also robust to phylogenetic uncertainty so long as temporal information was incorporated in estimates of divergence. The observed patterns are consistent with processes of environmental filtering during tropical forest succession giving way to other processes in primary forests including density‐dependence.
Study of a Port Design for Silo Blenders
Authors: Scrivens B. G. , Michaelides E. E. , Thomson F. M.
Published: November 2011

Experimental results are reported on two silo-blenders equipped with a new design of ports in their downcomers. None of the mixing streams was falling freely. The mixing of pellets within the ports is determined as a function of the port geometric characteristics such as awning angle, height of port, width of awning and width of the downcomer, and of the particle properties such as the angle of repose. It was observed that two dimensionless quantities are sufficient to describe the mixing fraction at the port. Visual observations on the flow near the port were made and the port’s mixing response surface was estimated. When the new port design was fitted in a cylindrical blender the active channel of the port was recorded as well as the average velocity distribution in the channel.
Hydraulically Amplified Terfenol-D Actuator for Adaptive Powertrain Mounts
Authors: Chakrabarti Suryarghya , Dapino Marcelo J.
Published: November 2011

A magnetostrictive actuator with a stroke of ±1 mm and a blocked force of ±25 N has been developed based on a Terfenol-D driver and a hydraulic stroke amplification mechanism. A mechanical model for this magneto-hydraulic actuator (MHA) is formulated by combining linear piezomagnetic relations for Terfenol-D and a lumped parameter mechanical system model describing the system vibrations. Friction at the fluid seals is described by the LuGre model. The model accurately describes the frequency-domain behavior of the actuator in mechanically-blocked and mechanically-free conditions. The MHA is benchmarked against a commercial electromagnetic driver used in active powertrain mounts in terms of mechanical performance (blocked force and unloaded displacement) and electrical power consumption. Measurements show that the MHA achieves more than twice the frequency bandwidth of the commercial device in the free displacement response, along with comparable static displacements. The commercial device produces higher blocked forces in the frequency range of 10 Hz to 120 Hz beyond which the generated forces are comparable up to 400 Hz. Spectral analysis reveals significant second order components in the commercial actuator displacement response which are absent in the MHA. Further, the MHA achieves superior performance than the commercial actuator operated at maximum current (6 A) with power consumption identical to that of the commercial actuator operated at minimum current (4 A).
NEUTRINO OSCILLATIONS, ENTANGLEMENT AND COHERENCE: A QUANTUM FIELD THEORY STUDY IN REAL TIME
Authors: WU JUN , HUTASOIT JIMMY A. , BOYANOVSKY DANIEL , HOLMAN RICHARD
Published: November 2011

The dynamics of neutrino mixing and oscillations are studied directly in finite real time in a model that effectively describes charged current weak interactions. Finite time corrections to the S-matrix result for the appearance and disappearance probabilities are obtained. It is observed that these effects may be of the same order of the S-matrix result in long-baseline appearance experiments. We argue that fundamentally, the S-matrix is ill-suited to describe long-baseline events due to the fact that the neutrino is produced in an entangled state with the charged lepton, which can be disentangled by the measurement of the charged lepton near the production site. The appearance and disappearance far-detection process is described from the time evolution of this disentangled "collapsed" state, allowing us to establish the conditions under which factorization of detection rates emerges in long-baseline experiments. We also study the time evolution of the reduced density matrix and show explicitly how oscillations are manifest in the off-diagonal terms, i.e. coherences, as a result of a finite time analysis. Lastly, we study a model for the "GSI anomaly" by obtaining the time evolution of the population of parent and daughter particles directly in real time. We confirm that the decay rate of parent and growth rate of daughters do not feature oscillatory behavior from interference of mass eigenstates.
Effects of a Cereal and Soy Dietary Formula on Rehabilitation of Undernourished Children at Ouagadougou, in Burkina Faso
Authors: Douamba Zoenabo , Martinetto Marina , Pietra Virginio , Pignatelli Salavatore , Schumacher Fabian , Nikiema Jean-Baptiste , Simpore Jacques
Published: November 2011

The New Misola consists of millet soybean, peanut, vitamins, minerals, and industrial amylase. Our objective is to demonstrate that porridge made from local grains and legumes restores the nutritional balance of malnourished children. The study was carried on 304 malnourished children aged 6–48 months including 172 girls and 132 boys from Saint Camille Medical Centre. At the beginning, these malnourished children had a WHZz-score of −3.10 and a WAZz-score of −3.85, which reflected, according to WHO, a severe malnutrition. After eight weeks of nutritional rehabilitation, a normal WHZ of −1.41 was obtained. These children recovered more than those in a similar study performed in 2006 with the old formula of Misola. This study shows that malnutrition remains a public health problem in Burkina Faso. It should be necessary that public health services and the epidemiologists work in synergy with nutritionists and “nutrigenetics” in order to combat malnutrition efficiently.
Race-Ethnic Differences of Sleep Symptoms in an Elderly Multi-Ethnic Cohort: The Northern Manhattan Study
Authors: Ramos Alberto R. , Wohlgemuth William K. , Dong Chuanhui , Gardener Hannah , Wright Clinton B. , Boden-Albala Bernadette , Elkind Mitchel S.V. , Sacco Ralph L. , Rundek Tatjana
Published: November 2011

Background: Sleep disorders are associated with stroke and may vary among elderly Hispanics, Blacks and Whites. We evaluated differences in sleep symptoms by race-ethnicity in an elderly population-based urban community sample. Methods: Snoring, daytime sleepiness and reported sleep duration were ascertained by standardized interviews as a part of the Northern Manhattan Study, a prospective cohort study of vascular risk factors and stroke risk in a multi-ethnic urban population. Sleep symptoms were compared amongst race-ethnic groups using logistic regression models. Results: A total of 1,964 stroke-free participants completed sleep questionnaires. The mean age was 75 ± 9 years, with 37% men, with 60% Hispanics, 21% Blacks and 19% Whites. In models adjusted for demographic and vascular risk factors, Hispanics had increased odds of frequent snoring (odds ratio, OR: 3.6, 95% confidence interval, CI: 2.3–5.8) and daytime sleepiness (OR: 2.8, 95% CI: 1.7–4.5) compared to White participants. Hispanics were more likely to report long sleep (≧9 h of sleep, OR: 1.8, 95% CI: 1.1–3.1). There was no difference in sleep symptoms between Black and White participants. Conclusion: In this cross-sectional analysis among an elderly community cohort, snoring, sleepiness and long sleep duration were more common in Hispanics. Sleep symptoms may be surrogate markers for an underlying sleep disorder which may be associated with an elevated risk of stroke and may be modified by clinical intervention.
A Critical Comparison of the So-called ‘Lawsuit’ in the Baptismal Rites of Theodore of Mopsuestia and Narsai of Nisibis
Authors: Witkamp Nathan
Published: November 2011

Abstract

Theodore of Mopsuestia’s baptismal homilies 1-3 and Narsai of Nisibis’ liturgical homilies 21 and 22 are valuable sources concerning the Syrian baptismal liturgy. It is commonly held that Narsai’s rite is heavily influenced by Theodore’s. Some scholars even go that far to picture Narsai as Theodore’s copycat. Such a view would have profound consequences for our perception of continuity and discontinuity within the Eastern baptismal tradition. However, the present comparative study of an often neglected pre-baptismal part of the rite both Narsai and Theodore describe as a “Lawsuit” or “Judgment” (dinā) reveals significant differences between both liturgies that make an exclusive dependance improbable. These differences must be taken into account if we want to get a clear picture of the relationship of both rites with each other and the larger Syrian tradition.
Efficacy of Light-Activated Sealant on Enamel Demineralization in Orthodontic Patients: An Atomic Force Microscope Evaluation
Authors: Shinaishin Suzi F , Ghobashy Safaa A , EL-Bialy Tarek H
Published: November 2011

Objective:

The purpose of this study was to investigate the efficacy of (Pro Seal) sealant in preventing enamel decalcification in-vivo and compare its effect with fluoride varnish and unfilled sealant using atomic force microscopy.

Materials and Methods:

Eight orthodontic patients who were candidates for extraction of all first premolars for orthodontic treatment were recruited to this study. Thirty two premolars (upper and lower) were randomly divided into four groups (n=8) for each group, 4 maxillary and 4 mandibular); Control (no -treatment); Fluoride varnish, Unfilled sealant (Light Bond) and filled sealant (Pro-Seal). After two months the brackets were debonded and the teeth were extracted and prepared for Atomic force microscopic scanning. Each sample was scanned twice at two different scan areas 50 and 10µm at the buccal cervical third of the crown. Images were recorded with slow scan rate and resolution and the mean roughness height and total surface area were calculated for each scan area. Comparison between groups was performed using one way analysis of variance test with level of significance was set to be 0.05.

Results:

Pro Seal treated samples show the lowest roughness height and total surface area.

Conclusion:

Pro Seal was the most effective prophylaxis technique in preventing enamel demineralization during orthodontic treatment.
Volumetric, viscometric and optical study of molecular interactions in binary mixtures of diethyl malonate with ketones at 303.15, 308.15 and 313.15K
Authors: Rathnam Manapragada , Mohite Sudhir , Kumar Manapragada
Published: November 2011

Density ?, viscosity ?, and refractive index nD were measured for the binary
mixtures of diethyl malonate with ketones (acetophenone, cyclopentanone,
cyclohexanone and 3-pentanone) at temperatures (303.15, 308.15 and 313.15) K
over the entire composition range. Excess volume VE, deviation in viscosity
??, excess Gibb?s free energy of activation for viscous flow ?GE and
deviation in molar refraction ?R were determined from the experimental data
and computed results were fitted to the Redlich-Kister polynomial equation.
The values of VE, ??, ?GE, and ?R were plotted against the mole fraction of
diethyl malonate. The observed positive and negative values of excess
parameters for all the studied binary mixtures were explained on the basis of
intermolecular interactions present in these mixtures. Further different
empirical relations were used to correlate the binary mixture viscosities and
refractive indices.
Validation of a new multiplex assay against individual immunoassays for the quantification of reproductive, stress, and energetic metabolism biomarkers in urine specimens
Authors: Salvante Katrina G. , Brindle Eleanor , Mcconnell Daniel , O'connor Kathleen , Nepomnaschy Pablo A.
Published: November 2011

Measuring multiple hormones simultaneously in a single assay saves sample volume, labor, time, reagents, money, and consumables. Thus, multiplex arrays represent a faster, more economically and ecologically sound alternative to singleton assays.

Objectives:

 To validate a new, commercially available multiplex female array produced by Quansys Biosciences against individual immunoassays for the quantification of six hormones in urine samples from women in different reproductive stages.

Methods:

 Urine samples were analyzed using the new Quansys multiplex female hormone array and compared with well‐established individual immunoassays for adiponectin, free cortisol, c‐peptide, estrone‐3‐glucuronide (E1G), follicle stimulating hormone beta‐subunit (FSH‐beta), and human chorionic gonadotropin beta‐subunit (hCG‐beta). Correlations between assays were assessed using Pearson correlation, linear regression and Bland–Altman analysis. The temporal profiles of free cortisol, E1G, FSH‐beta, and hCG‐beta were also compared.

Results:

 The multiplex array was highly correlated with the individual immunoassays for five of the tested hormones (Pearson's correlation coefficient ≥0.75), and yielded temporal patterns of hormone profiles consistent with the individual immunoassays for free cortisol, E1G, FSH‐beta, and hCG‐beta.

Conclusions:

  The Quansys multiplex female hormone array is a valid alternative method to individual immunoassays for the quantification of stress, reproductive and energetic hormones and metabolites in human urine samples and can be used to examine the dynamic interactions between these hormones. Am. J. Hum. Biol., 2012. © 2011 Wiley Periodicals, Inc.
Two photoluminescent polymers based on fluorene and 2,4,6‐triphenyl pyridine: Synthesis and electroluminescence
Authors: Jiang Hong Ji , Gao Zhi Qiang , Deng Xian Yu , Chen Run Feng , Huang Wei
Published: November 2011

Two fluorene and triphenyl pyridine‐based linear and dendronized copolymers, P1 and P2, were synthesized and fully characterized by 1H‐NMR, 13C‐NMR, and matrix assistant laser desorption/ionization time‐of‐flight mass spectra, respectively. The absorption, photoluminescence (PL) behavior, and energy band gaps of P1 and P2 relative to those of polyfluorene end‐capped with benzene (P0) were examined through UV–vis, photoluminescent spectra, and cyclic voltammetry. The UV–vis absorption and PL emission behavior of P0 and P1 were hardly affected by molecular architecture, while those of P2 were strongly correlated with the dendronized molecular frameworks. Cyclic voltammetry studies indicated the lower highest occupied molecular orbital energy level and wider band gap of P2 thin solid film relative to those of P0 and P1. The new polymers were thermally stable up to 410°C. The better luminance and external quantum efficiencies of P1 relative to those of P0 in polymer light‐emitting diode (PLED) applications are due to improved electron injection, charge trapping and recombination at the pyridine sites. Through the experiments, it is found that the triphenyl pyridyl segments and excimers‐formation make pronounced contribution to long wavelength emission in P1‐based blue light‐emitting materials, and the analogous materials containing 2,4,6‐triphenyl pyridyl unit of P1 constitute highly attractive materials for white PLED applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Evaluation of the factors affecting avicel reactivity using multi‐stage enzymatic hydrolysis
Authors: Yu Zhiying , Jameel Hasan , Chang Hou‐min , Philips Richard , Park Sunkyu
Published: November 2011

Multi‐stage and single‐stage enzymatic hydrolysis of cellulose (Avicel PH‐101) were conducted to investigate individual factors that affect the rate‐reducing kinetics of enzymatic hydrolysis. Understanding factors affecting enzymatic hydrolysis of Avicel will help improve hydrolysis of various biomasses. Product inhibition, enzyme deactivation, and the changes of substrate are potential factors that can affect the hydrolysis efficiency of Avicel. Multi‐stage enzymatic hydrolysis resulted in 36.9% and 25.4% higher carbohydrate conversion as compared to a single‐stage enzymatic hydrolysis with an enzyme loading of 5 and 20 FPU/g in a 96 h reaction. However, a decline in carbohydrate conversion of 1.6% and 2.6% was observed through each stage with 5 and 20 FPU/g, respectively. This indicated that the substrate became more recalcitrant as hydrolysis progressed. The decreased reactivity was not due to crystallinity because no significant change in crystallinity was detected by X‐ray diffraction. Product inhibition was significant at low enzyme loading, while it was marginal at high enzyme loading. Therefore, product inhibition can only partially explain this decreased conversion. Another important factor, enzyme deactivation, contributed to 20.3% and 25.4% decrease in the total carbohydrate conversion of 96 h hydrolysis with 5 and 20 FPU/g, respectively. This work shows that an important reason for the decreased Avicel digestibility is the effect of enzyme blockage, which refers to the enzymes that irreversibly adsorb on accessible sites of substrate. About 45.3% and 63.2% of the total decreased conversion at the end of the 8th stage with 5 and 20 FPU/g, respectively, was due to the presence of irreversibly adsorbed enzymes. This blockage of active sites by enzymes has been speculated by other researchers, but this article shows further evidence of this effect. Biotechnol. Bioeng. 2012; 109:1131–1139. © 2011 Wiley Periodicals, Inc.
The effect of age on glucose uptake and GLUT1 and GLUT4 expression in rat skeletal muscle
Authors: dos Santos J. M. , Benite‐Ribeiro S. A. , Queiroz G. , Duarte J. A.
Published: November 2011

During the life span, phenotypic and structural modifications on skeletal muscle contribute to a reduction on glucose uptake either in basal state or triggered by insulin, but the underlying mechanisms for this decline are not entirely identified. A reduction in the expression of skeletal muscle glucose transporters (GLUTs), glucose transporter type 1 (GLUT1) and glucose transporter type 4 (GLUT4), has been associated to such phenomena, but unlike the case of insulin, only few studies have addressed the effect of age on muscle‐contraction‐induced glucose uptake. The aim of the study was to investigate the influence of age on GLUT1 and GLUT4 expression in skeletal muscle and its relation to the glucose uptake induced by muscle contraction. For this purpose, soleus muscle from Wistar rats aged 4, 10, 22 and 42 weeks were isolated and electrically stimulated (30 min, 10 Hz, 20 V, 0.2 ms). After stimulation, glucose uptake and GLUT1 and GLUT4 expression and localisation were evaluated. Muscle contraction caused an increase in glucose uptake in all studied groups. In addition, the absolute rates of glucose uptake were negatively correlated with age. The expression of GLUT4 was lower in older animals, whereas no relation between age and GLUT1 expression was found. Immunohistochemistry confirmed the ontogenic effect on GLUT4 expression and suggested an age‐related modification on GLUT1 distribution within the muscle fibres; for instance, this protein seems to be present mainly out of the sarcoplasm. The present findings demonstrate that the ability of muscle contraction to increase glucose uptake is not influenced by age, whereas glucose uptake under basal conditions decreases with age. Copyright © 2011 John Wiley & Sons, Ltd.
Small Heart With Low Cardiac Output for Orthostatic Intolerance in Patients With Chronic Fatigue Syndrome
Authors: Miwa Kunihisa , Fujita Masatoshi
Published: November 2011

Background:

The etiology of chronic fatigue syndrome (CFS) is unknown. Orthostatic intolerance (OI) is common in CFS patients. Recently, small heart with low cardiac output has been postulated to be related to the genesis of both CFS and OI.

Hypothesis:

Small heart is associated with OI in patients with CFS.

Methods:

Study CFS patients were divided into groups of 26 (57%) CFSOI(+) and 20 (43%) CFSOI(−) according to the presence or absence of OI. In addition, 11 OI patients and 27 age‐ and sex‐matched control subjects were studied. Left ventricular (LV) dimensions and function were determined echocardiographically.

Results:

The mean values of cardiothoracic ratio, systemic systolic and diastolic pressures, LV end‐diastolic dimension, LV end‐systolic dimension, stroke volume index, cardiac index, and LV mass index were all significantly smaller in CFSOI(+) patients than in CFSOI(−) patients and healthy controls, and also in OI patients than in controls. A smaller LV end‐diastolic dimension (<40 mm) was significantly (P<0.05) more prevalently noted in CFSOI(+) (54%) and OI (45%) than in CFSOI(−) (5%) and controls (4%). A lower cardiac index (<2 L/min/mm2) was more prevalent in CFSOI(+) (65%) than in CFSOI(−) (5%, P<0.01), OI (27%), and controls (11%, P<0.01).

Conclusions:

A small size of LV with low cardiac output was noted in OI, and its degree was more pronounced in CFSOI(+). A small heart appears to be related to the genesis of OI and CFS via both cerebral and systemic hypoperfusion. CFSOI(+) seems to constitute a well‐defined and predominant subgroup of CFS. © 2011 Wiley Periodicals, Inc.

The authors have no funding, financial relationships, or conflicts of interest to disclose.
Comments on the Bohm Criterion and on the Determination of the Ion Velocity at the Sheath Edge in Non‐Maxwellian Plasma
Authors: Jauberteau J. L. , Jauberteau I.
Published: November 2011

This work is devoted to the study of the Bohm criterion in the general case of the electron energy distribution function (EEDF). Investigations are performed by means of a Monte Carlo integration method. We resolve the cold fluid equation system describing the ion motion within the sheath, assuming collisionless conditions, singly charged and mono kinetic incoming ions (BOHM model). Results confirm that the limit ion velocity at the sheath edge to assure a monotone electric field with a positive charge over the entire sheath is vi ≥ (kTe/Mi) or εi ≥ 1/3 <εe> in the case of Maxwellian electrons. We show that in the case of a Druyvesteyn electron energy distribution, this limit is larger, it is εi ≥ 0.6 <εe>. The study is also extended to other distributions functions. Because of the large controversy in recent publications, concerning the boundary conditions at the sheath entrance, we discuss the collisionless conditions at the sheath edge according to the plasma parameters. It is shown that in a collisionless sheath, the condition ni(χ) ≥ ne(χ) can be used to determine the limit ion velocity at the sheath edge of the negatively biased collector (Langmuir probe for instance) (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Gaming Exercise to Explore Problem‐Solving versus Relational Activities for River Floodplain Management
Authors: Stefanska Joanna , Magnuszewski Piotr , Sendzimir Jan , Romaniuk Patrycja , Taillieu Tharsi , Dubel Anna , Flachner Zsuzsanna , Balogh Peter
Published: November 2011

This paper describes a new gaming tool that allows players (e.g. water managers and farmers) to explore the consequences of their interactions in managing river floodplains. To facilitate the process of creating and testing new policies that would help to accommodate disordering events, e.g. floods, we developed a system dynamics model of floodplain agriculture that drives an interactive game. The Floodplain Management Game can be used as an educational resource, knowledge elicitation technique or transition management tool for agriculture and river management. The key feature is that it unites technical (problem‐solving) and relational issues in one game. In multiple areas it has proven a useful tool for participants to experience the challenges of policy‐making for managing rivers as well as for floodplain agriculture and for scientists to examine how stakeholders make decisions about such options. Copyright © 2011 John Wiley & Sons, Ltd and ERP Environment.
Bond‐selective imaging of deep tissue through the optical window between 1600 and 1850 nm
Authors: Wang Pu , Wang Han‐Wei , Sturek Michael , Cheng Ji‐Xin
Published: November 2011

We report the employment of an optical window between 1600 nm and 1850 nm for bond‐selective deep tissue imaging through harmonic vibrational excitation and acoustic detection of resultant pressure waves. In this window where a local minimum of water absorption resides, we found a 5 times enhancement of photoacoustic signal by first overtone excitation of the methylene group CH2 at 1730 nm, compared to the second overtone excitation at 1210 nm. The enhancement allows 3D mapping of intramuscular fat with improved contrast and of lipid deposition inside an atherosclerotic artery wall in the presence of blood. Moreover, lipid and protein are differentiated based on the first overtone absorption profiles of CH2 and methyl group CH3 in this window. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In vivo degradation and bone response of a composite coating on Mg–Zn–Ca alloy prepared by microarc oxidation and electrochemical deposition
Authors: Chen Shuai , Guan Shaokang , Li Wen , Wang Huanxin , Chen Juan , Wang Yisheng , Wang Haitao
Published: November 2011

Composite coatings with hydroxyapatite (HA), octacalcium phosphate (OCP) in electrochemical deposition (ED) layers and MgO, Mg3(PO4)2 in microarc oxidation (MAO) layers were prepared by ED and MAO on Mg–Zn–Ca alloy to improve the corrosion resistance and bone response. Substrates and coated samples were implanted in the femur shaft of rabbits to observe in vivo degradation behavior during 50 weeks. Results showed that the degradation rate of the substrates was much faster than the coated at 8, 12 weeks and became close to the coated at 18 weeks postoperatively. The composite coatings prevented the substrate from rapid release of magnesium ions at the interface and gradually degraded at the same time. The composite coatings induced more newly formed bone tissue and faster bone response. Overall, reduced degradation rate and improved bone response were achieved by the composite coatings. Thus, the composite coatings on Mg–Zn–Ca alloy are promising for clinical application in the future. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 100B: 533–543, 2012.
The cathodic behavior of titanium: Serum effect
Authors: Contu Francesco
Published: November 2011

The cathodic behavior of titanium was investigated in inorganic buffer solutions and in fetal bovine serum through potential sweep techniques. Under cathodic polarization, the oxygen reduction and the hydrogen evolution reactions were observed. It was found that the activity of the electrode toward the electron transfer increased with decreasing the electrode surface charge. The polarization curves recorded in serum displayed the same features as those observed in inorganic buffered solutions. However, organic molecules were likely adsorbed onto the titanium surface and the adsorption reactions were potential dependant. Additionally, it was noticed that the buffer capacity of serum could be overwhelmed by the progressive interface alkalinization during cathodic polarization. Furthermore, serum affected the corrosion current of the implant materials and the effect was pH‐dependent. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 100B: 544–552, 2011.
Ni ion release, osteoblast–material interactions, and hemocompatibility of hafnium‐implanted NiTi alloy
Authors: Zhao Tingting , Li Yan , Zhao Xinqing , Chen Hong , Zhang Tao
Published: November 2011

Hafnium ion implantation was applied to NiTi alloy to suppress Ni ion release and enhance osteoblast–material interactions and hemocompatibility. The auger electron spectroscopy, x‐ray photoelectron spectroscopy, and atomic force microscope results showed that a composite TiO2/HfO2 nanofilm with increased surface roughness was formed on the surface of NiTi, and Ni concentration was reduced in the superficial surface layer. Potentiodynamic polarization tests displayed that 4 mA NiTi sample possessed the highest Ebr − Ecorr, 470 mV higher than that of untreated NiTi, suggesting a significant improvement on pitting corrosion resistance. Inductively coupled plasma mass spectrometry tests during 60 days immersion demonstrated that Ni ion release rate was remarkably decreased, for example, a reduction of 67% in the first day. The water contact angle increased and surface energy decreased after Hf implantation. Cell culture and methyl‐thiazol‐tetrazolium indicated that Hf‐implanted NiTi expressed enhanced osteoblasts adhesion and proliferation, especially after 7 days culture. Hf implantation decreased fibrinogen adsorption, but had almost no effect on albumin adsorption. Platelets adhesion and activation were suppressed significantly (97% for 4 mA NiTi) and hemolysis rate was decreased by at least 57% after Hf implantation. Modified surface composition and morphology and decreased surface energy should be responsible for the improvement of cytocompatibility and hemocompatibility. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Investigation of lysine acrylate containing poly(N‐isopropylacrylamide) hydrogels as wound dressings in normal and infected wounds
Authors: Jiang Bin , Larson Jeffery C. , Drapala Pawel W. , Pérez‐Luna Víctor H. , Kang‐Mieler Jennifer J. , Brey Eric M.
Published: November 2011

The design of materials for cutaneous wound dressings has advanced from passive wound covers to bioactive materials that promote skin regeneration and prevent infection. Crosslinked poly(N‐isopropylacrylamide) (PNIPAAm)‐based hydrogels have been investigated for a number of biomedical applications. While these materials can be used for drug delivery, limited cell interactions restrict their biological activity. In this article, acryoyl‐lysine (A‐Lys) was incorporated into poly(ethylene glycol) crosslinked PNIPAAm to enhance biological activity. A‐Lys could be incorporated into the hydrogels to improve cellular interaction in vitro, while maintaining swelling properties and thermoresponsive behavior. Polyhexamethylene biguanide, an antimicrobial agent, could be encapsulated and released from the hydrogels and resulted in decreased bacteria counts within 2 hours. Two in vivo animal wound models were used to evaluate the hydrogel wound dressing. First, application of the hydrogels to a rodent cutaneous wound healing model resulted in significant increase in healing rate when compared with controls. Moreover, the hydrogels were also able to decrease bacteria levels in an infected wound model. These results suggest that PNIPAAm hydrogels containing A‐Lys are promising wound dressings due to their ability to promote healing and deliver active antimicrobial drugs to inhibit infection. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Fast profiling of chemical constituents in Yiqing Capsule by ultra‐performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry
Authors: Zheng Guo‐Dong , Li Kai , Li Yue‐shan , Liu E‐Hu
Published: November 2011

An ultra‐performance liquid chromatography/electrospray ionization tandem mass spectrometry (UPLC‐ESI‐MSn) has been developed for structural characterization and identification of multi‐constituents in Yiqing Capsule, a well‐known combined herbal remedy prepared from the extract mixtures of Rhizoma Coptidis, Radix et Rhizoma Rhei and Radix Scutellariae. The UPLC analysis was performed on an Agilent ZorBax SB‐C18 column (4.6 mm×50 mm, 1.8 μm) and gradient elution of 0.1% formic acid solution and acetonitrile in 16 min. Based on their retention times and mass spectra in comparison with the data from standards or references, a total of 29 compounds including 3 phenolic acids and 4 anthraquinones from Radix et Rhizoma Rhei, 8 alkaloids from Rhizoma Coptidis and 14 flavonoids from Radix Scutellariae were unambiguously identified or tentatively characterized in the complex system. The MS data and fragmentation information of two isomers of feruloylquinic acid were first reported in Radix et Rhizoma Rhei and in Yiqing Capsules. This study is expected to be accepted as an effective and reliable pattern for comprehensive and systematic characterization of this commonly used Chinese herbal preparation.
Combined histone deacetylase and cyclooxygenase inhibition achieves enhanced antiangiogenic effects in lung cancer cells
Authors: Wang Xiaoqi , Li Guangyuan , Wang Antai , Zhang Zhenfeng , Merchan Jaime R. , Halmos Balazs
Published: November 2011

Prostaglandin E2 (PGE2) is an important pro‐angiogenic and pro‐proliferative cytokine and the key enzymes modulating its levels, cyclooxygenase (COX)‐2 and 15‐hydroxyprostaglandin dehydrogenase (15‐PGDH) play important opposing roles in carcinogenesis. Previously we found loss of 15‐PGDH expression in lung cancer and its reactivation leads to strong in vivo tumor‐suppressive effect via an antiangiogenic mechanism. Here, we find that HDAC inhibitors (HDACI), such as trichostatin A (TSA) and vorinostat could reactivate 15‐PGDH expression but overall induce PGE2 generation and this is the result of concomitant induction of COX‐1 and ‐2 leading to functional promotion of endothelial cell proliferation and capillary formation. Direct TSA treatment inhibits endothelial cell proliferation and capillary formation in our study in line with prior reports as HDACIs have been shown to directly inhibit angiogenesis. The elevation of PGE2 levels induced by HDACI is potently neutralized by indomethacin (INN) or Celecoxib co‐treatment and accordingly, angiogenesis is more effectively inhibited when using conditioned medium of co‐treatment than either alone confirming that this effect is mediated via the PGE2 axis. Accordingly, blockage of EP2/4 receptors mitigates the stimulation of angiogenesis by excessive PGE2 generation mediated by TSA. In this study, we identify a potentially adverse effect of HDACIs through induction of both 15‐PGDH and COX‐2 leading to elevated PGE2 levels and thereby stimulation of angiogenesis. Co‐treatment of TSA and INN shows more potent anti‐angiogenic effects by inducing 15‐PGDH and inhibiting COX‐2. Overall, our results suggest that combined HDACI and COX inhibition should be explored clinically to achieve more meaningful benefits from HDACI therapy in lung cancer. © 2011 Wiley Periodicals, Inc.