Context.
The abundance of
α
-elements provides an important fossil signature in Galactic archaeology to trace the chemical evolution of the different disc populations. High-precision chemical ...abundances are crucial to improving our understanding of the chemodynamical properties present in the Galaxy. However, deriving precise abundance estimations in the metal-rich disc (M/H > 0 dex) is still challenging.
Aims.
The aim of this paper is to analyse different error sources affecting magnesium abundance estimations from optical spectra of metal-rich stars.
Methods.
We derived Mg abundances for 87522 high-resolution spectra of 2210 solar neighbourhood stars from the AMBRE Project, and selected the 1172 best parametrised stars with more than four repeated spectra. For this purpose, the GAUGUIN automated abundance estimation procedure was employed.
Results.
The normalisation procedure has a strong impact on the derived abundances, with a clear dependence on the stellar type and the line intensity. For non-saturated lines, the optimal wavelength domain for the local continuum placement should be evaluated using a goodness-of-fit criterion, allowing mask-size dependence with the spectral type. Moreover, for strong saturated lines, applying a narrow normalisation window reduces the parameter-dependent biases of the abundance estimate, increasing the line-to-line abundance precision. In addition, working at large spectral resolutions always leads to better results than at lower ones. The resulting improvement in the abundance precision makes it possible to observe both a clear thin-thick disc chemical distinction and a decreasing trend in the magnesium abundance even at supersolar metallicities.
Conclusions.
In the era of precise kinematical and dynamical data, optimising the normalisation procedures implemented for large spectroscopic stellar surveys would provide a significant improvement to our understanding of the chemodynamical patterns of Galactic populations.
Context.
Sulfur is a volatile chemical element that plays an important role in tracing the chemical evolution of the Milky Way and external galaxies. However, its nucleosynthesis origin and abundance ...variations in the Galaxy are still unclear because the number of available stellar sulfur abundance measurements is currently rather small.
Aims.
The goal of the present article is to accurately and precisely study the sulfur content of large number of stars located in the solar neighbourhood.
Methods.
We use the parametrisation of thousands of high-resolution stellar spectra provided by the AMBRE Project, and combine it with the automated abundance determination GAUGUIN to derive local thermodynamic equilibrium sulfur abundances for 1855 slow-rotating FGK-type stars. This is the largest and most precise catalogue of sulfur abundances published to date. It covers a metallicity domain as high as ∼2.5 dex starting at M/H ∼ −2.0 dex.
Results.
We find that the sulfur-to-iron abundances ratio is compatible with a plateau-like distribution in the metal-poor regime, and then starts to decrease continuously at M/H ∼ −1.0 dex. This decrease continues towards negative values for supersolar metallicity stars as recently reported for magnesium and as predicted by Galactic chemical evolution models. Moreover, sulfur-rich stars having metallicities in the range − 1.0, −0.5 have very different kinematical and orbital properties with respect to more metal-rich and sulfur-poor ones. Two disc components, associated with the thin and thick discs, are thus seen independently in kinematics and sulfur abundances. The sulfur radial gradients in the Galactic discs have also been estimated. Finally, the enrichment in sulfur with respect to iron is nicely correlated with stellar ages: older metal-poor stars have higher S/M ratios than younger metal-rich ones.
Conclusions.
This work has confirmed that sulfur is an
α
-element that could be considered to explore the Galactic populations properties. For the first time, a chemo-dynamical study from the sulfur abundance point of view, as a stand-alone chemical element, is performed.
Context.
The abundance of
α
-elements relative to iron (
α
/Fe) is an important fossil signature in Galactic archaeology for tracing the chemical evolution of disc stellar populations. High-precision ...chemical abundances, together with accurate stellar ages, distances, and dynamical data, are crucial to infer the Milky Way formation history.
Aims.
The aim of this paper is to analyse the chemodynamical properties of the Galactic disc using precise magnesium abundance estimates for solar neighbourhood stars with accurate
Gaia
astrometric measurements.
Methods.
We estimated ages and dynamical properties for 366 main sequence turn-off stars from the AMBRE Project using PARSEC isochrones together with astrometric and photometric values from
Gaia
DR2. We use precise global metallicities M/H and Mg/Fe abundances from a previous study in order to estimate gradients and temporal chemodynamic relations for these stars.
Results.
We find a radial gradient of −0.099 ± 0.031 dex kpc
−1
for M/H and +0.023 ± 0.009 dex kpc
−1
for the Mg/Fe abundance. The steeper Mg/Fe gradient than that found in the literature is a result of the improvement of the AMBRE Mg/Fe estimates in the metal-rich regime. In addition, we find a significant spread of stellar age at any given Mg/Fe value, and observe a clear correlated dispersion of the Mg/Fe abundance with metallicity at a given age. While for M/H ≤ − 0.2, a clear age–Mg/Fe trend is observed, more metal-rich stars display ages from 3 up to 12 Gyr, describing an almost flat trend in the Mg/Fe–age relation. Moreover, we report the presence of radially migrated and/or churned stars for a wide range of stellar ages, although we note the large uncertainties of the amplitude of the inferred change in orbital guiding radii. Finally, we observe the appearance of a second chemical sequence in the outer disc, 10–12 Gyr ago, populating the metal-poor, low-Mg/Fe tail. These stars are more metal-poor than the coexisting stellar population in the inner parts of the disc, and show lower Mg/Fe abundances than prior disc stars of the same metallicity, leading to a chemical discontinuity. Our data favour the rapid formation of an early disc that settled in the inner regions, followed by the accretion of external metal-poor gas –probably related to a major accretion event such as the
Gaia
-Enceladus/Sausage one– that may have triggered the formation of the thin disc population and steepened the abundance gradient in the early disc.
Context.
The X-shooter Spectral Library (XSL) is a large empirical stellar library used as a benchmark for the development of stellar population models. The inclusion of
α
-element abundances is ...crucial to disentangling the chemical evolution of any stellar system.
Aims.
The aim of this paper is to provide a catalogue of high-precision, accurate magnesium and calcium abundances from a wide variety of stars that are well distributed in the Hertzsprung-Russell (HR) diagram.
Methods.
We originally performed an analysis of the derived Mg and Ca abundances for medium-resolution spectra of 611 stars from the XSL Data Release 2. For this purpose, we used the GAUGUIN automated abundance estimation code to fit the ultraviolet-blue (UVB) and visible (VIS) spectra. We tested the consistency of the atmospheric parameters and chemical abundances with the
Gaia
DR3 and the AMBRE Project datasets.
Results.
We finally obtained precise Mg/Fe and Ca/Fe abundances for 192 and 217 stars, respectively, from which 174 stars have measurements in both elements. The stars cover a broad effective temperature range of 4000 <
T
eff
< 6500 K, surface gravity of 0.3 < log(
g
) < 4.8 cm s
−2
, and metallicity of −2.5 < Fe/H < +0.4 dex. We find an excellent agreement with the abundance estimates from the AMBRE:HARPS and the
Gaia
-RVS (Radial Velocity Spectrometer) analysis. Moreover, the resulting abundances reproduce a plateau in the metal-poor regime followed by a decreasing trend even at supersolar metallicities, as predicted by Galactic chemical evolution models.
Conclusions.
This catalogue is suitable for improving the modelling of evolutionary stellar population models with empirical
α
enhancements, which could significantly contribute to the analysis of external galaxies’ abundances in the near future.
Sulfur is a volatile chemical element that plays an important role in tracing the chemical evolution of galaxies. However, its nucleosynthesis origin and abundance variations are still unclear. The ...goal of the present article is to accurately and precisely study the S-content of large number of stars located in the solar neighbourhood. We use the parametrisation of thousands of HR stellar spectra provided by the AMBRE Project, and combine it with the automated abundance determination GAUGUIN to derive LTE sulfur abundances for 1855 slow-rotating FGK-type stars. This is the largest and most precise catalogue of S-abundances published to date. It covers a metallicity domain as high as ~2.5dex starting at M/H~-2.0dex. We find that the S/M abundances ratio is compatible with a plateau-like distribution in the metal-poor regime, and then starts to decrease continuously at M/H~-1.0dex. This decrease continues towards negative values for supersolar metallicity stars as recently reported for Mg and as predicted by Galactic chemical evolution models. Moreover, sulfur-rich stars having M/H in the range -1.0,-0.5 have very different kinematical and orbital properties with respect to more metal-rich and sulfur-poor ones. Two disc components, associated with the thin and thick discs, are thus seen independently in kinematics and sulfur abundances. The sulfur radial gradients in the Galactic discs have also been estimated. Finally, the enrichment in sulfur with respect to iron is nicely correlated with stellar ages: older metal-poor stars have higher S/M ratios than younger metal-rich ones. This work has confirmed that sulfur is an alfa-element that could be considered to explore the Galactic populations properties.
INTRODUCTIONIt has been observed in recent years that levels of such molecules as calcitonin gene-related peptide (CGRP) and, to a lesser extent, the pituitary adenylate cyclase-activating peptide ...are elevated during migraine attacks and in chronic migraine, both in the cerebrospinal fluid and in the serum. Pharmacological reduction of these proteins is clinically significant, with an improvement in patients' migraines. It therefore seems logical that one of the main lines of migraine research should be based on the role of CGRP in the pathophysiology of this entity.DEVELOPMENTThe Spanish Society of Neurology's Headache Study Group decided to draft this document in order to address the evidence on such important issues as the role of CGRP in the pathophysiology of migraine and the mechanism of action of monoclonal antibodies and gepants; and to critically analyse the results of different studies and the profile of patients eligible for treatment with monoclonal antibodies, and the impact in terms of pharmacoeconomics.CONCLUSIONSThe clinical development of gepants, which are CGRP antagonists, for the acute treatment of migraine attacks, and CGRP ligand and receptor monoclonal antibodies offer promising results for these patients.
La neuralgia del trigémino (NT) es un tipo de dolor neuropático que afecta a una o más ramas del nervio trigémino. Aunque su prevalencia poblacional es relativamente baja, la NT supone un problema ...muy importante tanto en las consultas de neurología como en las urgencias por la dificultad para el diagnóstico y el tratamiento y el elevado impacto sobre la calidad de vida de las personas que la padecen. Por estos motivos, el Grupo de Estudio de Cefaleas de la Sociedad Española de Neurología ha elaborado un documento de consenso sobre el manejo de esta patología.
Este documento ha sido redactado por un comité de expertos utilizando la nomenclatura de la clasificación de la International Headache Society (IHS), analizando la evidencia científica publicada sobre diagnóstico y tratamiento y estableciendo unas recomendaciones prácticas con niveles de evidencia.
El diagnóstico de la NT es clínico. La International Classification of Headache Disorders en su tercera edición (ICHD-3) clasifica el dolor atribuible a una lesión o enfermedad del nervio trigémino en NT y neuropatía trigeminal dolorosa. A su vez, la NT puede dividirse en tres tipos principales según la etiología del dolor: clásica, idiopática y secundaria. Es recomendable la realización de una resonancia magnética (RM) craneal a todo paciente con diagnóstico clínico de NT para descartar causas secundarias. Para estudiar la presencia de una compresión neurovascular con RM se recomienda la aplicación de los protocolos de imagen FIESTA, DRIVE o CISS. El tratamiento inicialmente será farmacológico. En pacientes seleccionados con respuesta insuficiente o mala tolerancia a fármacos se debe valorar el tratamiento quirúrgico.
Trigeminal neuralgia (TN) is a chronic neuropathic pain disorder affecting one or more branches of the trigeminal nerve. Despite its relatively low global prevalence, TN is an important healthcare problem both in neurology departments and in emergency departments due to the difficulty of diagnosing and treating the condition and its significant impact on patients’ quality of life. For all these reasons, the Spanish Society of Neurology's Headache Study Group has developed a consensus statement on the management of TN.
This document was drafted by a panel of neurologists specialising in headache, who used the terminology of the International Headache Society. We analysed the published scientific evidence on the diagnosis and treatment of TN and establish practical recommendations with levels of evidence.
The diagnosis of TN is based on clinical criteria. Pain attributed to a lesion or disease of the trigeminal nerve is divided into TN and painful trigeminal neuropathy, according to the International Classification of Headache Disorders, third edition. TN is further subclassified into classical, secondary, or idiopathic, according to aetiology. Brain MRI is recommended in patients with clinical diagnosis of TN, in order to rule out secondary causes. In MRI studies to detect neurovascular compression, FIESTA, DRIVE, or CISS sequences are recommended. Pharmacological treatment is the initial choice in all patients. In selected cases with drug-resistant pain or poor tolerance, surgery should be considered.
It has been observed in recent years that levels of such molecules as calcitonin gene–related peptide (CGRP) and, to a lesser extent, the pituitary adenylate cyclase–activating peptide are elevated ...during migraine attacks and in chronic migraine, both in the cerebrospinal fluid and in the serum. Pharmacological reduction of these proteins is clinically significant, with an improvement in patients’ migraines. It therefore seems logical that one of the main lines of migraine research should be based on the role of CGRP in the pathophysiology of this entity.
The Spanish Society of Neurology’s Headache Study Group decided to draft this document in order to address the evidence on such important issues as the role of CGRP in the pathophysiology of migraine and the mechanism of action of monoclonal antibodies and gepants; and to critically analyse the results of different studies and the profile of patients eligible for treatment with monoclonal antibodies, and the impact in terms of pharmacoeconomics.
The clinical development of gepants, which are CGRP antagonists, for the acute treatment of migraine attacks, and CGRP ligand and receptor monoclonal antibodies offer promising results for these patients.
En los últimos años se ha observado que moléculas como el péptido relacionado con el gen de la calcitonina (CGRP) y, en menor grado, el péptido activador de la adenilato-ciclasa pituitaria (PACAP) estaban elevadas durante los ataques de migraña y en la migraña crónica tanto en líquido cefalorraquídeo como en suero y que su reducción farmacológica tenía una significación clínica con una mejoría en la migraña de los pacientes. Es lógico por tanto que una de las principales líneas de investigación en migraña se base en el papel del CGRP en la fisiopatología de esta entidad.
Desde el Grupo de Estudio de Cefaleas de la Sociedad Española de Neurología nos planteamos la redacción de este documento, cuyo objetivo es abordar, basándonos en la evidencia publicada, cuestiones tan importantes como el papel del CGRP en la fisiopatología de la migraña, el mecanismo de acción de los AMC y de los gepantes, el análisis crítico de los resultados de los diferentes estudios, el perfil del paciente que podría ser candidato al tratamiento con AMC y su impacto en términos de farmacoeconomía.
El desarrollo clínico de los gepantes, antagonistas del CGRP, para el tratamiento agudo del ataque de migraña y de los anticuerpos monoclonales (AMC) contra ligando y contra el receptor del CGRP, ofrecen resultados esperanzadores para nuestros pacientes.
INTRODUCTIONIn the field of headaches, onabotulinumtoxinA (onabotA) is well established as a treatment for chronic migraine (CM). In recent years, it has been used increasingly to treat other primary ...headaches (high-frequency episodic migraine, trigeminal-autonomic cephalalgias, nummular headache) and trigeminal neuralgia. As this treatment will progressively be incorporated in the management of these patients, we consider it necessary to reflect, with a fundamentally practical approach, on the possible indications of onabotA, beyond CM, as well as its administration protocol, which will differ according to the type of headache and/or neuralgia. DEVELOPMENTThis consensus document was drafted based on a thorough review and analysis of the existing literature and our own clinical experience. The aim of the document is to serve as guidelines for professionals administering onabotA treatment. The first part will address onabotA's mechanism of action, and reasons for its use in other types of headache, from a physiopathological and clinical perspective. In the second part, we will review the available evidence and studies published in recent years. We will add an "expert recommendation" based on our own clinical experience, showing the best patient profile for this treatment and the most adequate dose and administration protocol. CONCLUSIONTreatment with onabotA should always be individualised and considered in selected patients who have not responded to conventional therapy.
En los últimos años se ha observado que moléculas como el péptido relacionado con el gen de la calcitonina (CGRP) y, en menor grado, el péptido activador de la adenilato-ciclasa pituitaria estaban ...elevadas durante los ataques de migraña y en la migraña crónica tanto en líquido cefalorraquídeo como en suero y que su reducción farmacológica tenía una significación clínica con una mejoría en la migraña de los pacientes. Es lógico por tanto que una de las principales líneas de investigación en migraña se base en el papel del CGRP en la fisiopatología de esta entidad.
Desde el Grupo de Estudio de Cefaleas de la Sociedad Española de Neurología nos planteamos la redacción de este documento, cuyo objetivo es abordar, basándonos en la evidencia publicada, cuestiones tan importantes como el papel del CGRP en la fisiopatología de la migraña, el mecanismo de acción de los anticuerpos monoclonales y de los gepantes, el análisis crítico de los resultados de los diferentes estudios, el perfil del paciente que podría ser candidato al tratamiento con anticuerpos monoclonales y su impacto en términos de farmacoeconomía.
El desarrollo clínico de los gepantes, antagonistas del CGRP, para el tratamiento agudo del ataque de migraña y de los anticuerpos monoclonales contra ligando y contra el receptor del CGRP ofrecen resultados esperanzadores para nuestros pacientes.
It has been observed in recent years that levels of such molecules as calcitonin gene–related peptide (CGRP) and, to a lesser extent, the pituitary adenylate cyclase–activating peptide are elevated during migraine attacks and in chronic migraine, both in the cerebrospinal fluid and in the serum. Pharmacological reduction of these proteins is clinically significant, with an improvement in patients’ migraines. It therefore seems logical that one of the main lines of migraine research should be based on the role of CGRP in the pathophysiology of this entity.
The Spanish Society of Neurology's Headache Study Group decided to draft this document in order to address the evidence on such important issues as the role of CGRP in the pathophysiology of migraine and the mechanism of action of monoclonal antibodies and gepants; and to critically analyse the results of different studies and the profile of patients eligible for treatment with monoclonal antibodies, and the impact in terms of pharmacoeconomics.
The clinical development of gepants, which are CGRP antagonists, for the acute treatment of migraine attacks, and CGRP ligand and receptor monoclonal antibodies offer promising results for these patients.
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