bluuebunny/crossref_metadata_2025_split huggingface dataset:
B‐vitamins for neuroprotection: Narrowing the evidence gap
Authors: Nachum‐Biala Yaarit , Troen Aron M. 
Published: March 2012

AbstractA compelling and extensive epidemiological literature documents the strong association of inadequate status of folate, vitamin B12, and to a lesser degree vitamin B6, with increased risk of neurodegenerative and cerebrovascular disease. Mildly elevated plasma total homocysteine, which is biochemically related to low status of these B‐vitamins, is similarly associated with increased risk for these conditions. This, together with experimental data showing that experimental B‐vitamin deficiency and/or hyperhomocysteinemia can cause a variety of neurological and vascular deficits in animals, has provided the evidence base and motivation for a growing number of large randomized, double‐blind clinical trials aimed at determining the efficacy and safety of B‐vitamin supplementation for preserving cognitive function in older adults. Despite some encouraging trials showing benefit of B‐vitamins for slowing brain atrophy and cognitive decline, the majority of these studies have not demonstrated that B‐vitamin supplementation has protective or therapeutic cognitive benefit. There are many possible explanations for the inconsistency between the clinical trials and for the discrepancy between their findings and the predictions of the epidemiological evidence. Among these are the possibility of inadequate hypotheses guiding the trials, design limitations of the individual trials, and inherent limitations of nutritional randomized clinical trials. Resolving these issues will be crucial for designing definitive trials and ultimately for guiding nutritional interventions for cognitive protection.
Non‐enzymatic palladium recovery on microbial and synthetic surfaces
Authors: Rotaru Amelia‐Elena , Jiang Wei , Finster Kai , Skrydstrup Troels , Meyer Rikke Louise 
Published: March 2012

AbstractThe use of microorganisms as support for reduction of dissolved Pd(II) to immobilized Pd(0) nanoparticles is an environmentally friendly approach for Pd recovery from waste. To better understand and engineer Pd(0) nanoparticle synthesis, one has to consider the mechanisms by which Pd(II) is reduced on microbial surfaces. Escherichia coli, Shewanella oneidensis, and Pseudomonas putida were used as model organisms in order to elucidate the role of microbial cells in Pd(II) reduction under acidic conditions. Pd(II) was reduced by formate under acidic conditions, and the process occurred substantially faster in the presence of cells as compared to cell‐free controls. We found no difference between native (untreated) and autoclaved cells, and could demonstrate that even a non‐enzymatic protein (bovine serum albumin) stimulated Pd(II) reduction as efficiently as bacterial cells. Amine groups readily interact with Pd(II), and to specifically test their role in surface‐assisted Pd(II) reduction by formate, we replaced bacterial cells with polystyrene microparticles functionalized with amine or carboxyl groups. Amine‐functionalized microparticles had the same effect on Pd(II) reduction as bacterial cells, and the effect could be hampered if the amine groups were blocked by acetylation. The interaction with amine groups was confirmed by infrared spectroscopy on whole cells and amine‐functionalized microparticles. In conclusion, bio‐supported Pd(II) reduction on microbial surfaces is possibly mediated by a non‐enzymatic mechanism. We therefore suggest the use of amine‐rich biomaterials rather than intact cells for Pd bio‐recovery from waste. Biotechnol. Bioeng. 2012; 109:1889–1897. © 2012 Wiley Periodicals, Inc.
Bacterial β‐glucosidase function and metabolic activity depend on soil management in semiarid rainfed agriculture
Authors: Cañizares Rosa , Moreno Beatriz , Benitez Emilio 
Published: March 2012

AbstractGenomic and transcriptomic approaches were used to gain insights into the relationship between soil management and bacterial‐mediated functions in an olive orchard agroecosystem. Four management practices were assessed in a 30‐year trial in a semiarid Mediterranean region. Transcriptional activity of bacterial 16S rRNA genes increased in noncovered soils, indicating higher microbial maintenance requirements to thrive in less favorable environmental conditions. The 16S rRNA transcript:gene copy ratio confirmed this assumption and pointed toward a much higher constitutive expression from rRNA operons in noncovered soils and to even higher expression levels when spontaneous vegetation was removed chemically. As described for 16S rRNA, potential transcription did not reveal the real transcription of bacterial β‐glucosidase genes, and higher gene expression in noncovered soils plus herbicides was evidenced. Since no relationship between total or soluble organic carbon and bacterial β‐glucosidase transcription was found, the above hypothesis could indicate either that soluble organic carbon is not the main pool of enzyme‐inducing substrates or that constitutive production of bacterial β‐glucosidase enzymes increases as soil conditions worsen.
Three‐Component Coupling of Aldehydes, Amines, and Alkynes Catalyzed by Oxidized Copper Nanoparticles on Titania
Authors: Albaladejo María José , Alonso Francisco , Moglie Yanina , Yus Miguel 
Published: March 2012

AbstractCopper nanoparticles (mainly as Cu2O) on titania have been shown to catalyze the multicomponent synthesis of propargylamines from aldehydes, amines, and alkynes (A3 coupling) effectively at 70 °C under solvent‐free conditions. Both aromatic and aliphatic aldehydes and alkynes have been combined with secondary amines to provide a wide range of propargylamines in moderate to excellent yields. Two examples of ketone/amine/alkyne (KA2) coupling are also included. The catalyst is easy to prepare, reusable at a low copper loading (0.5 mol‐%), and exhibits higher catalytic activity than some commercially available copper sources. Some mechanistic aspects of the reaction have also been examined, which have unveiled the participation of copper(I) acetylides in a heterogeneous process.
Implementation and validation of video monitoring for wood budgeting in a wandering piedmont river, the Ain River (France)
Authors: MacVicar Bruce , Piégay Hervé 
Published: March 2012

ABSTRACTThe transport of wood in rivers during floods is an important process that underlies differences in habitat and morphology between water courses and regions. Quantitative data are needed to properly address management objectives and balance wood budgets. In this study we use a streamside video camera to detect wood passage and measure quasi‐instantaneous rates of wood transport in the Ain River, France. The objectives are to verify the procedure, describe the relation between wood transport and discharge, and construct and validate a wood budget for the reach upstream of the camera. Verification of the procedure includes tests of detection frequency, wood velocity, and piece size. A log base two transformation is proposed to classify wood by piece length. It was found that a wood transport threshold occurs at approximately two thirds of the bankfull discharge. Wood transport follows a positive linear relation with discharge up to the bankfull discharge but is both more variable and less sensitive to discharge when the floodplain is inundated. Transport rates are approximately four times higher on the rising limb of the hydrograph than on the falling limb. Wood transport estimates from a three‐stage rating curve are two to 10 times higher than those from a wood budget using local and aerial surveys of upstream dynamics. Future work should address uncertainties related to wood diameter measurements, sampling length and frequency, and antecedent floods. Copyright © 2012 John Wiley & Sons, Ltd.
Generation and evolution of inelastic microstructures ‐ an overview
Authors: Hackl Klaus , Hoppe Ulrich , Kochmann Dennis M. 
Published: March 2012

AbstractIn this paper we give an overview on the modeling of inelastic microstructures using variational methods. We start by discussing the underlying variational principles for inelastic materials, derive evolution equations for internal variables, and introduce the concept of condensed energy. As a mathematical prerequisite we review the variational calculus of nonconvex potentials and the notion of relaxation. We use these instruments in order to study the initiation of plastic microstructures. Here we focus on a model of single‐slip crystal plasticity. Afterwards we move on to model the evolution of microstructures. We introduce the concept of essential microstructures and the corresponding relaxed energies and dissipation potentials, and derive evolution equations for microstructure parameters. We then present a numerical scheme by means of which the microstructure development can be computed, and show numerical results for particular examples (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Beneficial effect of plasma exchange in the treatment of toxic epidermal necrolysis: A series of four cases
Authors: Košt́ál Milan , Bláha Milan , Lánská Miriam , Košt́álová Marie , Bláha Vladimír , Štepánová Eva , Malý Jaroslav 
Published: March 2012

AbstractIntroduction: Toxic epidermal necrolysis (TEN) is a rare, life‐threatening disease with a high mortality rate that is linked to drug toxicity. There is a lack of data about the underlying pathophysiologic mechanisms and treatment options. The only widely accepted treatment of TEN is withdrawal of the offending drug followed by supportive care. The potential roles of corticosteroids, intravenous immunoglobulin (IVIG) and plasmapheresis (TPE) remain controversial. Aims: We present four patients with severe TEN (all with >80% involvement of body surface) who were treated with TPE following unsuccessful treatment with corticosteroids/IVIG. Methods: TPE was performed using a COBE Spectra blood cell separator. ACD‐A was used as anticoagulant fluid and the target‐washed plasma volume was one body volume. Plasma was replaced by a 5% solution of human albumin + Ringer's lactate. Results: The mean number of TPE sessions was 5.25 ± 2.22 (range 3–8). Drugs were implicated as an etiologic agent in each case. TPE led to prompt improvement of acute condition and general health as well as halting of disease progression. Additionally, the restoration of the epithelium began in all four patients. Conclusion: Plasmapheresis should be considered as an alternative treatment modality for patients with the most severe form of TEN if initial treatment with other agents, including corticosteroids and/or IVIG, fails. Drugs were suspected to be the cause of TEN in all four cases. J. Clin. Apheresis, 2012. © 2012 Wiley Periodicals, Inc.
Efficacy of in‐office bleaching techniques combined with the application of a casein phosphopeptide‐amorphous calcium phosphate paste at different moments and its influence on enamel surface properties
Authors: Gama Cunha Ana Gabriela , Meira De Vasconcelos Adriana Alcantara , Dutra Borges Boniek Castillo , De Oliveira Vitoriano Jussier , Alves‐Junior Clodomiro , Machado Claudia Tavares , Dos Santos Alex Jose Souza 
Published: March 2012

AbstractOBJECTIVES: The aim of this in vitro study was to investigate the efficacy of in‐office bleaching technique combined with the application of a casein phosphopeptide‐amorphous calcium phosphate (CPP‐ACP) paste (MI Paste–MI) at different moments and its influence on enamel surface properties. METHODS: Eighty bovine dental crowns were randomly allocated into eight groups (n = 10), and bleached with either 35% hydrogen peroxide (HP) or 37% carbamide peroxide (CP). Four different protocols of application of MI were considered: without MI, MI applied before bleaching, MI applied after bleaching, and MI applied both before and after bleaching. Bleaching effectiveness was measured by the VITA EasyShade spectrophotometer utilizing the CIEL*a*b* system (ΔE, ΔL*, Δa*, and Δb*). Color readings were measured at baseline, 7, 14, and 21 days. Hardness and roughness were measured at baseline (T0) and immediately after bleaching (T14). Data were subjected to the two‐way ANOVA for repeated measurements and Tukey's test at 5%. RESULTS: HP groups achieved the greatest color change. The application of a CPP‐ACP paste did not reduce the efficacy of bleaching peroxides. Samples bleached with CP showed decreased hardness at T14. Samples bleached with HP that received the application of MI before and before/after bleaching did not present hardness decrease at T14. Samples bleached with peroxides only and received MI after bleaching showed increased roughness at T14. CONCLUSIONS: The use of CPP‐ACP was able to prevent negative changes in roughness and hardness of bovine enamel when associated to hydrogen peroxide, and might be applied before/after the bleaching protocol. Microsc. Res. Tech. 75:1019–1025, 2012. © 2012 Wiley Periodicals, Inc.
A subspace shift technique for nonsymmetric algebraic Riccati equations associated with an M‐matrix
Authors: Iannazzo Bruno , Poloni Federico 
Published: March 2012

SUMMARYThe worst situation in computing the minimal nonnegative solution of a nonsymmetric algebraic Riccati equation associated with an M‐matrix occurs when the corresponding linearizing matrix has two very small eigenvalues, one with positive and one with negative real part. When both eigenvalues are exactly zero, the problem is called critical or null recurrent. Although in this case the problem is ill‐conditioned and the convergence of the algorithms based on matrix iterations is slow, there exist some techniques to remove the singularity and transform the problem to a well‐behaved one. Ill‐conditioning and slow convergence appear also in close‐to‐critical problems, but when none of the eigenvalues is exactly zero, the techniques used for the critical case cannot be applied. In this paper, we introduce a new method to accelerate the convergence properties of the iterations also in close‐to‐critical cases, by working on the invariant subspace associated with the problematic eigenvalues as a whole. We present numerical experiments that confirm the efficiency of the new method.Copyright © 2012 John Wiley & Sons, Ltd.
A DFT study on the standard electrode potentials of 2‐substituted imidazoles
Authors: Tugsuz Tugba 
Published: March 2012

AbstractExtensive density functional theory, calculations, with optimization of geometries and estimation of substituent effects, have been performed to investigate the electrode potentials of dimer and protonated cation structures of 2‐substituted imidazoles. The gas phase geometries of dimer, anion, protonated cation, and neutral structures of 2‐substituted imidazoles have been optimized using Boese‐Martin for kinetics (BMK) and the Minnesota 2005 (M05) hybrid functionals combined with the valence triple‐ζ quality with polarization function (TZVP) basis set. The geometries in the presence of acetonitrile solvent have been optimized using the conductor‐like polarizable continuum model model of solvation at the same levels of theory. Frequency calculations have been performed for all the structures and none of them is found to exhibit any imaginary frequency. NH‐‐‐H infrared harmonic frequencies have been calculated and compared with available experimental data. The substituent effects on the electrode potentials of imidazole have been investigated as electron donating CH3, OH, NH2, OCH3 and electron withdrawing NO2, Cl, F, Br groups, which are bonded to the second numbered carbon atom of the imidazole molecule. It has been found that electron donating substituents show more negative electrode potentials, whereas electron withdrawing substituents have the opposite effect. © 2012 Wiley Periodicals, Inc.
Naloxone can act as an analgesic agent without measurable chronic side effects in mice with a mutant mu‐opioid receptor expressed in different sites of pain pathway
Authors: Chou Shu‐Husan , Kao Jen‐Hsin , Tao Pao‐Luh , Law Ping‐Yee , Loh Horace H. 
Published: March 2012

AbstractMidbrain periaqueductal gray (PAG) and spinal cord dorsal horn are major action sites of opioid analgesics in the pain pathway. Our previous study has shown that opioid antagonists activate MORS196A‐CSTA (a mutant of mu‐opioid receptor) as full agonists in vitro cell models and naloxone showed antinociceptive effects after the expression of MORS196A‐CSTA in the spinal cord in mice. The purpose of this study is to investigate the site‐directed antinociceptive effects of naloxone in mice injected with dsAAV‐MORS196A‐CSTA‐EGFP at spinal cord or at periaqueductal gray. MORS196A‐CSTA‐EGFP was administered to ICR mice using dsAAV as vector. We measured MORS196A‐CSTA‐EGFP expression by detecting the EGFP visualization with a fluorescence microscope. The antinociceptive effect of naloxone was determined by tail‐flick test and hot plate test. Drug rewarding effect was evaluated by the conditioned place preference test. Naloxone (10 mg/kg, s.c.) elicited both supraspinal and spinal antinociceptive responses in mice injected with the virus at PAG while only spinal antinociceptive response was observed in mice injected with virus at dorsal horn region. Chronic naloxone treatment did not induce physical dependence or rewarding effect in mice injected with MORS196A‐CSTA‐EGFP in spinal cord or PAG. These data suggest that the observed naloxone‐induced antinociceptive response is the consequence of the local expression of MORS196A‐CSTA at specific sites of pain pathway. Injection of such MOR mutant and the systemic administration of naloxone can be a new strategy in the management of chronic pain without the various side effects associated with the use of morphine. Synapse, 2012. © 2012 Wiley Periodicals, Inc.
Optimization of culture medium composition for manganese peroxidase and tyrosinase production during Reactive Black 5 decolourization by the yeast Trichosporon akiyoshidainum
Authors: Martorell María M , Pajot Hipólito F. , Rovati José I. , Figueroa Lucía I. C. 
Published: March 2012

AbstractDecolourization and degradation of the diazo dye Reactive Black 5 was carried out by the yeast Trichosporon akiyoshidainum. A nine‐factor Plackett–Burman design was employed for the study and optimization of the decolourization process and production of manganese peroxidase (MnP) and tyrosinase activities. In the present study, 26 individual experiments were conducted and three responses were evaluated. Raising yeast extract concentration significantly enhanced decolourization and MnP production. Carbon and nitrogen sources, glucose and (NH4)2SO4, showed no significant effect on any response over the concentration range tested. Other culture medium components, such as CaCl2 or MgSO4, could be excluded from the medium formula, as they had no effect on the evaluated responses. Metal ions (Fe, Cu and Mn) showed different effects on decolourization and enzymatic activities. Addition of copper significantly enhanced MnP activity and decreased dye decolourization. On the contrary, iron had a positive effect on decolourization and no effect on enzyme production. Oddly, increasing manganese concentration had a positive effect on tyrosinase production without affecting decolourization or MnP activity. These results strongly suggest that dye decolourization should be regarded as a complex multi‐enzymatic process, where optimal medium composition should arise as a compromise between those optimal for each implied enzyme production. Copyright © 2012 John Wiley & Sons, Ltd.
The presence of heterospecific males causes an Allee effect
Authors: Kyogoku Daisuke , Nishida Takayoshi 
Published: March 2012

AbstractThe Allee effect is a positive causal relationship between any component of fitness and population density or size. Allee effects strongly affect the persistence of small or sparse populations. Predicting Allee effects remains a challenge, possibly because not all causal mechanisms are known. We hypothesized that reproductive interference (an interspecific reproductive interaction that reduces the fitness of the species involved) can generate an Allee effect. If the density of the interfering species is constant, an increase in the population of the species receiving interference may dilute the per capita effect of reproductive interference and may generate an Allee effect. To test this hypothesis, we examined the effect of heterospecific males on the relationship between per capita fecundity and conspecific density in Callosobruchus chinensis and C. maculatus. Of the two species, only C. maculatus females suffer reproductive interference from heterospecific males. Only C. maculatus, the species susceptible to reproductive interference, demonstrated an Allee effect, and only when heterospecific males were present. In contrast, C. chinensis, the species not susceptible to reproductive interference, demonstrated no Allee effect regardless of the presence of heterospecific males. Our results show that reproductive interference in fact generated an Allee effect, suggesting the potential importance of interspecific sexual interactions especially in small or sparse populations, even in the absence of a shared resource. It may be possible to predict Allee effects produced by this mechanism a priori by testing reproductive interference between closely related species.
Tracing sources and pathways of dissolved nitrate in forest and river ecosystems using high‐resolution isotopic techniques: a review
Authors: Ohte Nobuhito 
Published: March 2012

AbstractNitrogen inputs into stream and river ecosystems, and the factors influencing those inputs, are important for various ecological and environmental concerns. Reliable information on where and how nitrogen compounds flow into aquatic ecosystems is indispensable to understanding the nutrient status of these ecosystems. Such information should include the biogeochemical mechanisms and hydrological controls of nutrient leaching into rivers from terrestrial systems such as forests, agricultural fields, and urbanized areas. Advancements in stable isotopomer measurements over the past two decades have expanded the variety of target substances and the precision with which they can be investigated. The high‐throughput microbial denitrifier method allows for simultaneous measurement of nitrogen and oxygen isotope ratios and can provide high‐resolution spatiotemporal information on both nitrate sources and biogeochemical processes. Although advanced techniques of stable isotope analysis have been used extensively to detect sources and estimate the relative contributions of multi‐source systems in various rivers, there are still new horizons in investigating nitrogen transformations. For example, stable isotopes of oxygen (18O and 17O) occurring in nitrate due to atmospheric deposition can be used as natural tracers for evaluating internal nitrogen cycling; these isotopes are distinct from the oxygen within microbially generated nitrate in soils and water bodies. Another future challenge is improved use of nitrous oxide isotopomers in evaluating the relative contributions of nitrification and denitrification. Such analysis could provide insight into the nitrogen transformation that occurs under redox conditions at the boundary between terrestrial and aquatic systems, where nitrification and denitrification often occur simultaneously in soil and aquatic environments.