Nax−y Hy Ti2−x Fex O4 ·nH2 O nanosheets with lepidocrocite-like layered structure synthesized by hydrothermal treatment of ilmenite sand

Nax−yHyTi2−xFexO4·nH2O nanosheets with lepidocrocite-like layered structure were produced through alkaline hydrothermal treatment at very low temperatures (130°C) from ilmenite sand. The crystal structure, morphology and optical properties were investigated by X-Ray diffraction, transmission electron microscopy, selected area electron diffraction, energy dispersive spectroscopy and UV-Vis spectroscopy. The product shows leaf-like nanosheet morphology with thickness <30 nm and lengths <1 µm. Three lepidocrocite-like titanates (Imm2 space group) with similar a and c lattice parameters but different interlayer distances (b/2) were identified. This appears to be the first preparation of lepidocrocite-like layered nanosheets by a simple, energy efficient (low temperature) and low cost (starting from mineral sand) procedure

Enhancement of titanate nanotubes dispersion for reinforcement of nylon-II nanocomposites

The purpose of the present study was to investigate the effect of titanate nanotubes (TINTs) dispersion in the mechanical properties of Nylon 11 (polyamide 11) polymer. According ,to the existing literature small amounts of TTNTs used as reinforcement in polymer matrix improve properties such as tensile strength and stiffness. However, the addition of these nanoparticles may also lead to a decrease of strength of the composite if the nanotubes are not well dispersed in the polymer matrix. In this work two different routes were investigated to enhance the disl?ersion of TTNTs used as a reinforcement of nylon matrix nanocomposites: (1) chemical functionalization with 3-arninopropyltriethoxysilane; and (2) treatment with 2 kinds of surfactant - a cationic (CTAB) and an anionic (SDS). Characterization of the nanotubes was done by infrared spectroscopy, CHN elemental analysis, measurement of the specific surface area, thermogravimetric analysis, scanning electron microscopy and transmission electron microscopy. Nylon-II matrix nanocomposites were manufactured by microextrusion-microinjection and reinforced with 0.5 to 2.0 wt.-% of functionalized and surfactant treated nanotubes. Finally, mechanical and thermal properties as well as the microstructure of the nanocomposites were evaluated. The presentation will discuss the results and potential applications of these materials

Enhancement of titanate nanotubes dispersion for reinforcement of nylon-II nanocomposites

The purpose of the present study was to investigate the effect of titanate nanotubes (TINTs) dispersion in the mechanical properties of Nylon 11 (polyamide 11) polymer. According ,to the existing literature small amounts of TTNTs used as reinforcement in polymer matrix improve properties such as tensile strength and stiffness. However, the addition of these nanoparticles may also lead to a decrease of strength of the composite if the nanotubes are not well dispersed in the polymer matrix. In this work two different routes were investigated to enhance the disl?ersion of TTNTs used as a reinforcement of nylon matrix nanocomposites: (1) chemical functionalization with 3-arninopropyltriethoxysilane; and (2) treatment with 2 kinds of surfactant - a cationic (CTAB) and an anionic (SDS). Characterization of the nanotubes was done by infrared spectroscopy, CHN elemental analysis, measurement of the specific surface area, thermogravimetric analysis, scanning electron microscopy and transmission electron microscopy. Nylon-II matrix nanocomposites were manufactured by microextrusion-microinjection and reinforced with 0.5 to 2.0 wt.-% of functionalized and surfactant treated nanotubes. Finally, mechanical and thermal properties as well as the microstructure of the nanocomposites were evaluated. The presentation will discuss the results and potential applications of these materials

Impulsividad y conciencia del problema predicen la adherencia terapéutica y el abandono del tratamiento en el trastorno por juego de azar

Este estudio investiga el valor predictivo de la impulsividad como rasgo (evaluada con la escala de conducta impulsiva UPPS-P) y de covariados relevantes (variables sociodemográficas, severidad del juego de azar, estado de ánimo disfórico, otras conductas adictivas e inteligencia no verbal), con respecto al abandono del tratamiento y los niveles de cumplimiento de las prescripciones terapéuticas en pacientes con trastorno por juego de azar. Sesenta y seis pacientes con este trastorno, participantes del proyecto G-Brain, fueron evaluados inicialmente en impulsividad rasgo y en los covariados mencionados. Dicha evaluación se realizó durante los seis primeros meses desde el inicio de su tratamiento. En el seguimiento realizado a los 6 meses, 24 pacientes habían abandonado (grupo ABD) y 42 continuaban el tratamiento (grupo NABD). Los análisis multivariados con las subescalas de impulsividad mostraron diferencias prospectivas entre ambos grupos. Aparentemente, estas diferencias son atribuibles a las dimensiones afectivas de impulsividad (urgencias positiva y negativa). Entre ambas dimensiones, solo la urgencia positiva fue un predictor independiente de un ligero incremento en la probabilidad de abandono. Dentro del grupo NABD, un mayor grado de adherencia terapéutica vino predicho, de manera independiente, tanto por una baja búsqueda de sensaciones como por una mayor conciencia de los problemas vinculados al juego. Estos resultados sugieren que los rasgos de impulsividad de origen afectivo son predictores de abandono del tratamiento en pacientes con trastorno por juego. La conciencia de problemas asociados al juego de azar y una baja búsqueda de sensaciones predisponen a una mayor adherencia a las prescripciones terapéuticas

Efficacy and safety of the biosimilar ABP 501 compared with adalimumab in patients with moderate to severe rheumatoid arthritis: a randomised, double-blind, phase III equivalence study

Objectives ABP 501 is a Food and Drug Administration-approved biosimilar to adalimumab; structural, functional and pharmacokinetic evaluations have shown that the two are highly similar. We report results from a phase III study comparing efficacy, safety and immunogenicity between ABP 501 and adalimumab. Methods In this randomised, double-blind, active comparator-controlled, 26-week equivalence study, patients with moderate to severe active rheumatoid arthritis (RA) despite methotrexate were randomised (1:1) to ABP 501 or adalimumab (40 mg) every 2 weeks. Primary endpoint was risk ratio (RR) of ACR20 between groups at week 24. Primary hypothesis that the treatments were equivalent would be confirmed if the 90% CI for RR of ACR20 at week 24 fell between 0.738 and 1.355, demonstrating that ABP 501 is similar to adalimumab. Secondary endpoints included Disease Activity Score 28-joint count-C reactive protein (DAS28-CRP). Safety was assessed via adverse events (AEs) and laboratory evaluations. Antidrug antibodies were assessed to determine immunogenicity. Results A total of 526 patients were randomised (n=264, ABP 501; n=262 adalimumab) and 494 completed the study. ACR20 response at week 24 was 74.6% (ABP 501) and 72.4% (adalimumab). At week 24, the RR of ACR20 (90% CI) between groups was 1.039 (0.954, 1.133), confirming the primary hypothesis. Changes from baseline in DAS28-CRP, ACR50 and ACR70 were similar. There were no clinically meaningful differences in AEs and laboratory abnormalities. A total of 38.3% (ABP 501) and 38.2% (adalimumab) of patients tested positive for binding antidrug antibodies. Conclusions Results from this study demonstrate that ABP 501 is similar to adalimumab in clinical efficacy, safety and immunogenicity in patients with moderate to severe RA

Measurement of ISR-FSR interference in the processes e+ e- --> mu+ mu- gamma and e+ e- --> pi+ pi- gamma

Charge asymmetry in processes e+ e- --> mu+ mu- gamma and e+ e- --> pi+ pi- gamma is measured using 232 fb-1 of data collected with the BABAR detector at center-of-mass energies near 10.58 GeV. An observable is introduced and shown to be very robust against detector asymmetries while keeping a large sensitivity to the physical charge asymmetry that results from the interference between initial and final state radiation. The asymmetry is determined as afunction of the invariant mass of the final-state tracks from production threshold to a few GeV/c2. It is compared to the expectation from QED for e+ e- --> mu+ mu- gamma and from theoretical models for e+ e- --> pi+ pi- gamma. A clear interference pattern is observed in e+ e- --> pi+ pi- gamma, particularly in the vicinity of the f_2(1270) resonance. The inferred rate of lowest order FSR production is consistent with the QED expectation for e+ e- --> mu+ mu- gamma, and is negligibly small for e+ e- --> pi+ pi- gamma.Comment: 32 pages,29 figures, to be submitted to Phys. Rev.

Host Responses in Life-History Traits and Tolerance to Virus Infection in Arabidopsis thaliana

Knowing how hosts respond to parasite infection is paramount in understanding the effects of parasites on host populations and hence host–parasite co-evolution. Modification of life-history traits in response to parasitism has received less attention than other defence strategies. Life-history theory predicts that parasitised hosts will increase reproductive effort and accelerate reproduction. However, empirical analyses of these predictions are few and mostly limited to animal-parasite systems. We have analysed life-history trait responses in 18 accessions of Arabidopsis thaliana infected at two different developmental stages with three strains of Cucumber mosaic virus (CMV). Accessions were divided into two groups according to allometric relationships; these groups differed also in their tolerance to CMV infection. Life-history trait modification upon virus infection depended on the host genotype and the stage at infection. While all accessions delayed flowering, only the more tolerant allometric group modified resource allocation to increase the production of reproductive structures and progeny, and reduced the length of reproductive period. Our results are in agreement with modifications of life-history traits reported for parasitised animals and with predictions from life-history theory. Thus, we provide empirical support for the general validity of theoretical predictions. In addition, this experimental approach allowed us to quantitatively estimate the genetic determinism of life-history trait plasticity and to evaluate the role of life-history trait modification in defence against parasites, two largely unexplored issues

The Relationship of Within-Host Multiplication and Virulence in a Plant-Virus System

Background. Virulence does not represent any obvious advantage to parasites. Most models of virulence evolution assume that virulence is an unavoidable consequence of within-host multiplication of parasites, resulting in trade-offs between within-host multiplication and between-host transmission fitness components. Experimental support for the central assumption of this hypothesis, i.e., for a positive correlation between within-host multiplication rates and virulence, is limited for plant-parasite systems. Methodology/Principal Findings. We have addressed this issue in the system Arabidopsis thaliana-Cucumber mosaic virus (CMV). Virus multiplication and the effect of infection on plant growth and on viable seed production were quantified for 21 Arabidopsis wild genotypes infected by 3 CMV isolates. The effect of infection on plant growth and seed production depended of plant architecture and length of postembryonic life cycle, two genetically-determined traits, as well as on the time of infection in the plant's life cycle. A relationship between virus multiplication and virulence was not a general feature of this host-parasite system. This could be explained by tolerance mechanisms determined by the host genotype and operating differently on two components of plant fitness, biomass production and resource allocation to seeds. However, a positive relationship between virus multiplication and virulence was detected for some accessions with short life cycle and high seed weight to biomass ratio, which show lower levels of tolerance to infection. Conclusions/Significance. These results show that genotype-specific tolerance mechanisms may lead to the absence of a clear relationship between parasite multiplication and virulence. Furthermore, a positive correlation between parasite multiplication and virulence may occur only in some genotypes and/or environmental conditions for a given host-parasite system. Thus, our results challenge the general validity of the trade-off hypothesis for virulence evolution, and stress the need of considering the effect of both the host and parasite genotypes in analyses of host-parasite interactions. © 2007 Pagán et al.Ministerio de Educación y Ciencia, Spain.Peer Reviewe

The Relationship of Within-Host Multiplication and Virulence in a Plant-Virus System

Background. Virulence does not represent any obvious advantage to parasites. Most models of virulence evolution assume that virulence is an unavoidable consequence of within-host multiplication of parasites, resulting in trade-offs between within-host multiplication and between-host transmission fitness components. Experimental support for the central assumption of this hypothesis, i.e., for a positive correlation between within-host multiplication rates and virulence, is limited for plant-parasite systems. Methodology/Principal Findings. We have addressed this issue in the system Arabidopsis thaliana-Cucumber mosaic virus (CMV). Virus multiplication and the effect of infection on plant growth and on viable seed production were quantified for 21 Arabidopsis wild genotypes infected by 3 CMV isolates. The effect of infection on plant growth and seed production depended of plant architecture and length of postembryonic life cycle, two genetically-determined traits, as well as on the time of infection in the plant's life cycle. A relationship between virus multiplication and virulence was not a general feature of this host-parasite system. This could be explained by tolerance mechanisms determined by the host genotype and operating differently on two components of plant fitness, biomass production and resource allocation to seeds. However, a positive relationship between virus multiplication and virulence was detected for some accessions with short life cycle and high seed weight to biomass ratio, which show lower levels of tolerance to infection. Conclusions/Significance. These results show that genotype-specific tolerance mechanisms may lead to the absence of a clear relationship between parasite multiplication and virulence. Furthermore, a positive correlation between parasite multiplication and virulence may occur only in some genotypes and/or environmental conditions for a given host-parasite system. Thus, our results challenge the general validity of the trade-off hypothesis for virulence evolution, and stress the need of considering the effect of both the host and parasite genotypes in analyses of host-parasite interactions. © 2007 Pagán et al.Ministerio de Educación y Ciencia, Spain.Peer Reviewe