1,129 research outputs found
BAFF, APRIL and BAFFR on the pathogenesis of Immunoglobulin-A vasculitis
BAFF, APRIL and BAFF-R are key proteins involved in the development of B-lymphocytes and autoimmunity. Additionally, BAFF, APRIL and BAFFR polymorphisms were associated with immune-mediated conditions, being BAFF GCTGT>A a shared insertion-deletion genetic variant for several autoimmune diseases. Accordingly, we assessed whether BAFF, APRIL and BAFFR represent novel genetic risk factors for Immunoglobulin-A vasculitis (IgAV), a predominantly B-lymphocyte inflammatory condition. BAFF rs374039502, which colocalizes with BAFF GCTGT>A, and two tag variants within APRIL (rs11552708 and rs6608) and BAFFR (rs7290134 and rs77874543) were genotyped in 386 Caucasian IgAV patients and 806 matched healthy controls. No genotypes or alleles differences were observed between IgAV patients and controls when BAFF, APRIL and BAFFR variants were analysed independently. Likewise, no statistically significant differences were found in the genotype and allele frequencies of BAFF, APRIL or BAFFR when IgAV patients were stratified according to the age at disease onset or to the presence/absence of gastrointestinal (GI) or renal manifestations. Similar results were disclosed when APRIL and BAFFR haplotypes were compared between IgAV patients and controls and between IgAV patients stratified according to the clinical characteristics mentioned above. Our results suggest that BAFF, APRIL and BAFFR do not contribute to the genetic network underlying IgAV.Acknowledgements: We are indebted to the patients and healthy controls for their essential collaboration to this study. We also thank the National DNA Bank Repository (Salamanca) for supplying part of the control samples. This study was supported by European Union FEDER funds and `Fondo de Investigaciones Sanitarias´ (grant PI18/00042) from ‘Instituto de Salud Carlos III’ (ISCIII, Health Ministry, Spain). DP-P is a recipient of a Río Hortega programme fellowship from the ISCIII, co-funded by the European Social Fund (ESF, `Investing in your future´) (grant number CM20/00006). SR-M is supported by funds of the RETICS Program (RD16/0012/0009) (ISCIII, co-funded by the European Regional Development Fund (ERDF)). VP-C is supported by a pre-doctoral grant from IDIVAL (PREVAL 18/01). BA-M is a recipient of a `López Albo´ Post-Residency Programme funded by Servicio Cántabro de Salud. LL-G is supported by funds from IDIVAL (INNVAL20/06). OG is staff personnel of Xunta de Galicia (Servizo Galego de Saude (SERGAS)) through a research-staff stabilization contract (ISCIII/SERGAS) and his work is funded by ISCIII and the European Union FEDER fund (grant numbers RD16/0012/0014 (RIER) and PI17/00409). He is beneficiary of project funds from the Research Executive Agency (REA) of the European Union in the framework of MSCA-RISE Action of the H2020 Programme, Project 734899—Olive-Net. RL-M is a recipient of a Miguel Servet type I programme fellowship from the ISCIII, cofunded by ESF (`Investing in your future´) (grant number CP16/00033)
Unusual magneto-optical behavior induced by local dielectric variations under localized surface plasmon excitations
We study the effect of global and local dielectric variations on the polarization conversion rps response of ordered nickel nanowires embedded in an alumina matrix. When considering local changes, we observe a non-monotonous behavior of the rps, its intensity unusually modified far beyond to what it is expected for a monotonous change of the whole refractive index of the embedding medium. This is related to the local redistribution of the electromagnetic field when a localized surface plasmon is excited. This finding may be employed to develop and improve new biosensing magnetoplasmonic devices
Intrinsic Plasmon-Phonon Interactions in Highly Doped Graphene: A Near-Field Imaging Study.
Author's accepted versionFinal version available from ACS via the DOI in this recordAs a two-dimensional semimetal, graphene offers clear advantages for plasmonic applications over conventional metals, such as stronger optical field confinement, in situ tunability, and relatively low intrinsic losses. However, the operational frequencies at which plasmons can be excited in graphene are limited by the Fermi energy EF, which in practice can be controlled electrostatically only up to a few tenths of an electronvolt. Higher Fermi energies open the door to novel plasmonic devices with unprecedented capabilities, particularly at mid-infrared and shorter-wave infrared frequencies. In addition, this grants us a better understanding of the interaction physics of intrinsic graphene phonons with graphene plasmons. Here, we present FeCl3-intercalated graphene as a new plasmonic material with high stability under environmental conditions and carrier concentrations corresponding to EF > 1 eV. Near-field imaging of this highly doped form of graphene allows us to characterize plasmons, including their corresponding lifetimes, over a broad frequency range. For bilayer graphene, in contrast to the monolayer system, a phonon-induced dipole moment results in increased plasmon damping around the intrinsic phonon frequency. Strong coupling between intrinsic graphene phonons and plasmons is found, supported by ab initio calculations of the coupling strength, which are in good agreement with the experimental data.FJGA and PA-G acknowledge support from the Spanish Ministry of Economy and Competitiveness through the national programs MAT2014-59096-P and FIS2014-60195-JIN, respectively. MFC and SR acknowledge support from EPSRC (Grant no. EP/J000396/1, 281 EP/K017160/1, EP/K010050/1, EPG036101/1, EP/M001024/1, EPM- 002438/1), from Royal Society International Exchanges Scheme 2012/R3 and 2013/R2 and from European Commission (FP7-ICT-2013-613024-GRASP). SD, DNB and MF acknowledge support of ONR N00014-15-1-2671. DNB is the Moore Investigator in Quantum Materials funded by the Gordon and Betty Moore Foundation’s EPiQS Initiative through Grant GBMF4533
Tumour heterogeneity in glioblastoma assessed by MRI texture analysis: a potential marker of survival
Objective: The main objective of this retrospective work was the study of three-dimensional (3D) heterogeneity measures of post-contrast pre-operative MR images acquired with T1 weighted sequences of patients with glioblastoma (GBM) as predictors of clinical outcome. Methods: 79 patients from 3 hospitals were included in the study. 16 3D textural heterogeneity measures were computed including run-length matrix (RLM) features (regional heterogeneity) and co-occurrence matrix (CM) features (local heterogeneity). The significance of the results was studied using Kaplan?Meier curves and Cox proportional hazards analysis. Correlation between the variables of the study was assessed using the Spearman?s correlation coefficient. Results: Kaplan?Meyer survival analysis showed that 4 of the 11 RLM features and 4 of the 5 CM features considered were robust predictors of survival. The median survival differences in the most significant cases were of over 6 months. Conclusion: Heterogeneity measures computed on the post-contrast pre-operative T1 weighted MR images of patients with GBM are predictors of survival. Advances in knowledge: Texture analysis to assess tumour heterogeneity has been widely studied. However, most works develop a two-dimensional analysis, focusing only on one MRI slice to state tumour heterogeneity. The study of fully 3D heterogeneity textural features as predictors of clinical outcome is more robust and is not dependent on the selected slice of the tumour
Effects of an exercise program on hepatic metabolism, hepatic fat, and cardiovascular health in overweight/obese adolescents from Bogotá, Colombia (the HEPAFIT study): study protocol for a randomized controlled trial
Background: A considerable proportion of contemporary youth have a high risk of obesity-related disorders such
as cardiovascular disease, metabolic syndrome, or non-alcoholic fatty liver disease (NAFLD). Although there is consistent
evidence for the positive effects of physical activity on several health aspects, most adolescents in Colombia are
sedentary. It is, therefore, important to implement strategies that generate changes in lifestyle. The HEPAFIT study
aims to examine whether a 6-month exercise program has benefits for hepatic fat content and cardiovascular health
outcomes among overweight/obese adolescents from Bogotá, Colombia.
Methods/design: Altogether, 100 hundred overweight/obese, sedentary adolescents (aged 11–17 years) attending two
public schools in Bogotá, Colombia, will be included in a parallel-group randomized controlled trial. Adolescents will be
randomly assigned to an intervention group following one of four curricula: (1) the standard physical education
curriculum (60 min per week of physical activity, n = 25) at low-to-moderate intensity; (2) a high-intensity physical
education curriculum (HIPE, n = 25), consisting of endurance and resistance games and non-competitive activities,
such as running, gymkhanas, lifting, pushing, wrestling, or hauling, for 60-min sessions, three times per week, with
an energy expenditure goal of 300 to 500 kcal/session at 75–85% maximum heart rate (HRmax); (3) a low-to-moderate
intensity physical education curriculum (LIPE, n = 25) consisting of endurance and resistance games and non-competitive
activities (e.g., chasing, sprinting, dribbling, or hopping) for 60-min sessions, three times per week with an energy
expenditure goal of 300 kcal/session at 55–75% HRmax; and (4) a combined HIPE and LIPE curriculum (n = 25).
The HIPE, LIPE, and combined interventions were performed in addition to the standard physical education curriculum.
The primary outcome for effectiveness is liver fat content, as measured by the controlled attenuation parameter 1
week after the end of the intervention program.
Discussion: The translational focus may be suitable for collecting new information in a school setting on the
possible effects of physical activity interventions to reduce liver fat content and to improve metabolic profiles
and the cardiometabolic health of overweight/obese adolescents. This may lead to the more efficient use of
school physical education resources.The HEPAFIT study was carried out with the financial support of Instituto
Colombiano para el Desarrollo de la Ciencia y la Tecnología “Francisco José
de Caldas” COLCIENCIAS (code 59700 and no 122277757900). Katherine
González-Ruíz receive a scholarship from Universidad del Rosario, Colombia,
Escuela de Medicina y Ciencias de la Salud, to do a Doctorate. This article
presents independent research commissioned by COLCIENCIAS under its
Program Grants for Applied Research funding scheme (Convocatoria 777–2017)
Subjective response to antipsychotic treatment and compliance in schizophrenia. A naturalistic study comparing olanzapine, risperidone and haloperidol (EFESO Study)
BACKGROUND: In order to compare the effectiveness of different antipsychotic drugs in the treatment of schizophrenia it is very important to evaluate subjective response and compliance in patient cohorts treated according to routine clinical practice. METHOD: Outpatients with schizophrenia entered this prospective, naturalistic study when they received a new prescription for an antipsychotic drug. Treatment assignment was based on purely clinical criteria, as the study did not include any experimental intervention. Patients treated with olanzapine, risperidone or haloperidol were included in the analysis. Subjective response was measured using the 10-item version of the Drug Attitude Inventory (DAI-10), and treatment compliance was measured using a physician-rated 4 point categorical scale. RESULTS: A total of 2128 patients initiated treatment (as monotherapy) with olanzapine, 417 with risperidone, and 112 with haloperidol. Olanzapine-treated patients had significantly higher DAI-10 scores and significantly better treatment compliance compared to both risperidone- and haloperidol-treated patients. Risperidone-treated patients had a significantly higher DAI-10 score compared to haloperidol-treated patients. CONCLUSION: Subjective response and compliance were superior in olanzapine-treated patients, compared to patients treated with risperidone and haloperidol, in routine clinical practice. Differences in subjective response were explained largely, but not completely, by differences in incidence of EPS
Evolutionary and pulsational properties of white dwarf stars
Abridged. White dwarf stars are the final evolutionary stage of the vast
majority of stars, including our Sun. The study of white dwarfs has potential
applications to different fields of astrophysics. In particular, they can be
used as independent reliable cosmic clocks, and can also provide valuable
information about the fundamental parameters of a wide variety of stellar
populations, like our Galaxy and open and globular clusters. In addition, the
high densities and temperatures characterizing white dwarfs allow to use these
stars as cosmic laboratories for studying physical processes under extreme
conditions that cannot be achieved in terrestrial laboratories. They can be
used to constrain fundamental properties of elementary particles such as axions
and neutrinos, and to study problems related to the variation of fundamental
constants.
In this work, we review the essentials of the physics of white dwarf stars.
Special emphasis is placed on the physical processes that lead to the formation
of white dwarfs as well as on the different energy sources and processes
responsible for chemical abundance changes that occur along their evolution.
Moreover, in the course of their lives, white dwarfs cross different
pulsational instability strips. The existence of these instability strips
provides astronomers with an unique opportunity to peer into their internal
structure that would otherwise remain hidden from observers. We will show that
this allows to measure with unprecedented precision the stellar masses and to
infer their envelope thicknesses, to probe the core chemical stratification,
and to detect rotation rates and magnetic fields. Consequently, in this work,
we also review the pulsational properties of white dwarfs and the most recent
applications of white dwarf asteroseismology.Comment: 85 pages, 28 figures. To be published in The Astronomy and
Astrophysics Revie
Mitochondrial echoes of first settlement and genetic continuity in El Salvador
Background: From Paleo-Indian times to recent historical episodes, the Mesoamerican isthmus played an important role in the distribution and patterns of variability all around the double American continent. However, the amount of genetic information currently available on Central American continental populations is very scarce. In order to shed light on the role of Mesoamerica in the peopling of the New World, the present study focuses on the analysis of the mtDNA variation in a population sample from El Salvador.
Methodology/Principal Findings: We have carried out DNA sequencing of the entire control region of the mitochondrial DNA (mtDNA) genome in 90 individuals from El Salvador. We have also compiled more than 3,985 control region profiles from the public domain and the literature in order to carry out inter-population comparisons. The results reveal a predominant Native American component in this region: by far, the most prevalent mtDNA haplogroup in this country (at ~90%) is A2, in contrast with other North, Meso- and South American populations. Haplogroup A2 shows a star-like phylogeny and is very diverse with a substantial proportion of mtDNAs (45%; sequence range 16090–16365) still unobserved in other American populations. Two different Bayesian approaches used to estimate admixture proportions in El Salvador shows that the majority of the mtDNAs observed come from North America. A preliminary founder analysis indicates that the settlement of El Salvador occurred about 13,400±5,200 Y.B.P.. The founder age of A2 in El Salvador is close to the overall age of A2 in America, which suggests that the colonization of this region occurred within a few thousand years of the initial expansion into the Americas.
Conclusions/Significance: As a whole, the results are compatible with the hypothesis that today's A2 variability in El Salvador represents to a large extent the indigenous component of the region. Concordant with this hypothesis is also the observation of a very limited contribution from European and African women (~5%). This implies that the Atlantic slave trade had a very small demographic impact in El Salvador in contrast to its transformation of the gene pool in neighbouring populations from the Caribbean facade
Strategies in a metallophyte species to cope with manganese excess
The effect of exposure to high Mn concentration
was studied in a metallophyte species, Erica
andevalensis, using hydroponic cultures with a range
of Mn concentrations (0.06, 100, 300, 500, and
700 mg L-1). At harvest, biomass production, element
uptake, and biochemical indicators of metal
stress (leaf pigments, organic acids, amino acids,
phenols, and activities of catalase, peroxidase, superoxide
dismutase) were determined in leaves and roots.
Increasing Mn concentrations led to a decrease in
biomass accumulation, and tip leaves chlorosis was
the only toxicity symptom detected. In a similar way,
photosynthetic pigments (chlorophylls a and b, and
carotenoids) were affected by high Mn levels. Among
organic acids, malate and oxalate contents in roots
showed a significant increase at the highest Mn
concentration, while in leaves, Mn led to an increasing
trend in citrate and malate contents. An increase of Mn also induced an increase in superoxide dismutase
activity in roots and catalase activity in leaves. As
well, significant changes in free amino acids were
induced by Mn concentrations higher than
300 mg L-1, especially in roots. No significant
changes in phenolic compounds were observed in
the leaves, but root phenolics were significantly
increased by increasing Mn concentrations in treatments.
When Fe supply was increased 10 and 20 times
(7–14 mg Fe L-1 as Fe-EDDHA) in the nutrient
solutions at the highest Mn concentration
(700 mg Mn L-1), it led to significant increases in
photosynthetic pigments and biomass accumulation.
Manganese was mostly accumulated in the roots, and
the species was essentially a Mn excluder. However,
considering the high leaf Mn concentration recorded
without toxicity symptoms, E. andevalensis might be
rated as a Mn-tolerant speciesinfo:eu-repo/semantics/publishedVersio
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