A fast magnetic vector characterization method for quasi two-dimensional systems and heterostructures.

The use of magnetic vector tomography/laminography has opened a 3D experimental window to access the magnetization at the nanoscale. These methods exploit the dependence of the magnetic contrast in transmission to recover its 3D configuration. However, hundreds of different angular projections are required leading to large measurement times. Here we present a fast method to dramatically reduce the experiment time specific for quasi two-dimensional magnetic systems. The algorithm uses the Beer-Lambert equation in the framework of X-ray transmission microscopy to obtain the 3D magnetic configuration of the sample. It has been demonstrated in permalloy microstructures, reconstructing the magnetization vector field with a reduced number of angular projections obtaining quantitative results. The throughput of the methodology is × 10-× 100 times faster than conventional magnetic vector tomography, making this characterization method of general interest for the community.

Wine yeast selection in the Iberian Peninsula: Saccharomyces and non-Saccharomyces as drivers of innovation in Spanish and Portuguese wine industries.

Yeast selection for the wine industry in Spain started in 1950 for the understanding of the microbial ecology, and for the selection of optimal strains to improve the performance of alcoholic fermentation and the overall wine quality. This process has been strongly developed over the last 30 years, firstly on Saccharomyces cerevisiae, and, lately, with intense activity on non-Saccharomyces. Several thousand yeast strains have been isolated, identified and tested to select those with better performance and/or specific technological properties. The present review proposes a global survey of this massive ex-situ preservation of eukaryotic microorganisms, a reservoir of biotechnological solutions for the wine sector, overviewing relevant screenings that led to the selection of strains from 12 genera and 22 species of oenological significance. In the first part, the attention goes to the selection programmes related to relevant wine-producing areas (i.e. Douro, Extremadura, Galicia, La Mancha and Uclés, Ribera del Duero, Rioja, Sherry area, and Valencia). In the second part, the focus shifted on specific non-Saccharomyces genera/species selected from different Spanish and Portuguese regions, exploited to enhance particular attributes of the wines. A fil rouge of the dissertation is the design of tailored biotechnological solutions for wines typical of given geographic areas.

Effect of adding a positive memories' module in a trauma-focused cognitive-behavioural treatment for female survivors of intimate partner violence: trial protocol.

BACKGROUND: Trauma-focused cognitive-behavioural treatments have been proven to be effective for reducing symptoms in female survivors of intimate partner violence (IPV), although they still present some difficulties (e.g. significant drop-out rates, low adherence). Based on existing evidence about the difficulty of accessing memories of positive experiences among these women, we considered integrating positive memory evocation in trauma-focused treatments. The present study aims to test the effect of adding a positive memory module to trauma-focused CBT for female survivors of IPV. METHODS: The study is a single-blind, randomized controlled trial (RCT) comparing two trauma-focused CBT (with and without a positive memory module) for female survivors of IPV and a wait-list condition (superiority trial), including pretreatment and posttreatment measures, and follow-ups at 3, 6 and 12 months. Assessors of treatment outcome will be blinded to the trial arm. We aim to recruit 135 participants who will be randomized to one of the experimental conditions. The primary outcome is PTSD symptom severity. Secondary outcome measures include IPV, attitudes towards IPV, posttraumatic cognitions, centrality of trauma, self-concept, positive and negative affect, depression, anxiety, emotional dysregulation or health-related quality of life, as well as satisfaction with treatment. Moreover, adherence to and satisfaction with treatment will be considered. DISCUSSION: This study first analyses the effect of including positive memory evocation into a trauma-focused treatment for female survivors of IPV. This strategy aims to improve the effect of the treatments and enhance the healing of the trauma by developing a more integrated and emotionally modulated autobiographical narrative that contributes to the recovery and well-being of the victims. TRIAL REGISTRATION: ISRCTN73702156 . Registered on 10 March 2022.

Revealing 3D magnetization of thin films with soft X-ray tomography: magnetic singularities and topological charges.

The knowledge of how magnetization looks inside a ferromagnet is often hindered by the limitations of the available experimental methods which are sensitive only to the surface regions or limited in spatial resolution. Here we report a vector tomographic reconstruction based on soft X-ray transmission microscopy and magnetic dichroism data, which has allowed visualizing the three-dimensional magnetization in a ferromagnetic thin film heterostructure. Different non-trivial topological textures have been resolved and the determination of their topological charge has allowed us to identify a Bloch point and a meron-like texture. Our method relies only on experimental data and might be of wide application and interest in 3D nanomagnetism.

Stroke in systemic lupus erythematosus: epidemiology, mechanism, and long-term outcome.

OBJECTIVE: To determine stroke prevalence, mechanisms, and long-term outcome in a cohort of Hispanic patients with systemic lupus erythematosus (SLE). METHODS: We analyzed demographical data, the timing between SLE diagnosis and stroke onset, stroke type, recurrence, and outcomes from an institutional database of 4451 patients with SLE followed from 1993 to 2018. RESULTS: We observed 139 strokes (3.1%), for an incidence rate of 1.25 per 1000 person-years: 81 (58.3%) acute ischemic stroke (AIS), 19 (13.7%) subarachnoid hemorrhage (SAH), 17 (12.2%) cerebral venous thrombosis, 13 (9.4%) intracerebral hemorrhage (ICH), and 9 (6.5%) transient ischemic attack. Median time from SLE diagnosis to acute stroke was 60 months (interquartile range 12-132 months). AIS had a bimodal presentation with 26% occurring within the first year and 30% >10 years after SLE diagnosis. In contrast, 75% of ICH cases occurred >3 years (and 34% >10 years) after SLE diagnosis. The most important cause of AIS was secondary antiphospholipid syndrome (48%). Hypertension was associated with 69% of ICH cases, while aneurysmal rupture was observed in 78% of SAH cases. Excellent recovery at hospital discharge was observed in 65%. Stroke recurrence was observed in 7%. The long-term all-cause fatality rate was 8%. CONCLUSIONS: The prevalence of stroke in this cohort was 3.1%. Ischemic strokes had a bimodal presentation, occurring either early after SLE diagnosis or after a several-year delay. Half of the hemorrhagic strokes occurred >10 years after the diagnosis of SLE. Clinical outcome was usually good with a relatively low recurrence rate.

Chiral asymmetry detected in a 2D array of permalloy square nanomagnets using circularly polarized x-ray resonant magnetic scattering.

The sensitivity of circularly polarized x-ray resonant magnetic scattering (CXRMS) to chiral asymmetry has been demonstrated. The study was performed on a 2D array of Permalloy (Py) square nanomagnets of 700 nm lateral size arranged in a chess pattern, in a square lattice of 1000 nm lattice parameter. Previous x-ray magnetic circular dichroism photoemission electron microscopy (XMCD-PEEM) images on this sample showed the formation of vortices at remanence and a preference in their chiral state. The magnetic hysteresis loops of the array along the diagonal axis of the squares indicate a non-negligible and anisotropic interaction between vortices. The intensity of the magnetic scattering using circularly polarized light along one of the diagonal axes of the square magnets becomes asymmetric in intensity in the direction transversal to the incident plane at fields where the vortex states are formed. The asymmetry sign is inverted when the direction of the applied magnetic field is inverted. The result is the expected in the presence of an unbalanced chiral distribution. The effect is observed by CXRMS due to the interference between the charge scattering and the magnetic scattering.

Intrathecal formation of anticardiolipin antibodies in a patient with SLE-related relapsing longitudinal myelitis: a possible pathogenic connection.

BACKGROUND: Nontraumatic acute transverse myelitis (ATM) can occur in response to infectious, inflammatory and vascular triggers; 1% of patients with systemic lupus erythematosus (SLE) develop ATM, but the mechanism remains unknown. OBJECTIVE: The objective of this case report is to describe a case of intrathecal formation of anticardiolipin antibodies (aCL) during SLE-related ATM. METHODS: A single patient analysis was conducted. RESULTS: A 26-year-old housewife was diagnosed with SLE at age 19. Circulating aCL antibodies were positive at diagnosis. At age 21, she developed an episode of severe sepsis. At 23 years of age she developed an episode of ATM that left her paraplegic with a D10 sensory level, from which she recovered partially. Three years later, she developed a clinical relapse of ATM. During that second episode, serum levels of aCL were within normal limits, while cerebrospinal fluid levels were increased, suggesting intrathecal production of aCL. CONCLUSION: Here, we present a case of a woman who developed relapsing SLE-related longitudinally extensive ATM in whom intrathecal formation of aCL was demonstrated, suggesting that local production and cross-recognition of nervous tissue by those autoantibodies may be myelopathic.

Natural history of longitudinally extensive transverse myelitis in 35 Hispanic patients with systemic lupus erythematosus: good short-term functional outcome and paradoxical increase in long-term mortality.

Background and objective Acute transverse myelitis (TM) is an infrequent neurological complication of systemic lupus erythematosus (SLE). Short-term outcome varies widely between cohorts. Little is known about the epidemiology and long-term functional outcome of TM associated to SLE. Methods Patients with SLE and acute TM were identified during hospital admission, visits to the Emergency Room or the Neurology Outpatient Clinic. We evaluated ambispectively those patients with SLE presenting with clinical myelopathy and corroborated with spinal MRI. Cases were divided as partial (non-paralyzing) or complete (paralyzing). We determined long-term functional outcome as well as mortality in those patients with follow-up periods of at least five years. Results We identified 35 patients (partial, n = 15; complete, n = 20) in which complete clinical and imaging data were available (26 with follow-up ≥ 5 years). Patients with complete TM were significantly older than those with partial forms. Positive antiphospholipid antibodies were observed in 80% of patients, suggesting a possible mechanistical role. Surprisingly, functional recovery at one year was in general good; however, we observed a five-year mortality of 31% because of sepsis (in 10 cases) or pulmonary embolism (in one case). Conclusions Short-term outcome of SLE-related TM is generally good, and recurrence rate is low. However, we observed a long-term fatality rate of 31% for reasons unrelated to TM, suggesting that TM is a manifestation of severe immune dysregulation and a predictor of severity and mortality in patients with SLE.

Influence of freezing temperatures prior to freeze-drying on viability of yeasts and lactic acid bacteria isolated from wine.

AIMS: To determine the effect of three different freezing temperatures on post-freeze-drying survival rates of wine yeasts and lactic acid bacteria (LAB). To know if a similar freeze-drying protocol can be used for both micro-organisms. METHODS AND RESULTS: Cells from liquid culture media were recovered and concentrated in appropriate lyoprotectants. Aliquots of each strain were frozen at -20, -80 and -196°C before vacuum drying. Viable cell counts were done before freezing and after freeze-drying. Survival rates were calculated. Freezing temperatures differently affected yeast and bacteria survival. The highest survival rates were obtained at -20 and -80°C for yeasts, but at -196°C for LAB. Major differences in survival rates were recorded among freeze-dried yeasts, but were less drastic for LAB. Yeasts Pichia membranifaciens, Starmerella bacillaris and Metschnikowia pulcherrima, and LAB Lactobacillus paracasei, Pediococcus parvulus and Lactobacillus mali, were the most tolerant species to freeze-drying, regardless of freezing temperature. CONCLUSIONS: Yeast and LAB survival rates differed for each tested freezing temperature. For yeasts, -20°C ensured the highest post-freeze-drying viability and -196°C for LAB. SIGNIFICANCE AND IMPACT OF THE STUDY: Freezing temperature to freeze-dry cells is a crucial factor for ensuring good wine yeast and LAB survival. These results are important for appropriately preserving micro-organisms and for improving starter production processes.

Fascitis nodular de localización mamaria / Nodular fasciitis of the breast

La fascitis nodular es una neoplasia fibrosa autolimitada, que a menudo se confunde con un sarcoma debido a su rápido crecimiento y a su alta celularidad e índice mitótico. Se caracteriza por lesiones solitarias generalmente localizadas en fascias superficiales o profundas de tejidos blandos, sobre todo en las extremidades superiores y tronco de adultos jóvenes. La fascitis nodular de localización mamaria es excepcional y tanto clínica como radiológicamente puede simular un carcinoma mamario. Describimos los hallazgos clínicos, radiológicos e histopatológicos de un caso de fascitis nodular de localización mamaria en una mujer de 69 años de edad, que se inició con una tumoración palpable en unión de cuadrantes superiores de mama derecha de aparición brusca y rápido crecimiento. La biopsia percutánea caracteriza la lesión. Se realizó biopsia escisional, confirmándose el diagnóstico

Nodular fasciitis is a self-limiting fibrous neoplasm that is often mistaken for a sarcoma due to its rapid growth, cellularity and mitotic activity. It commonly arises in the superficial or deep fascia of the soft tissue, mostly in the upper extremities and trunk of young to middle-aged adults. In the breast, although rare, it can clinically and radiologically mimic a malignant neoplasm. We describe the clinical, radiological and histopathological findings of a case of nodular fasciitis located in the breast in a 69-year-old woman who presented with a palpable mass in the junction of the upper quadrants of the right breast. The mass showed abrupt onset and rapid growth. The lesion was characterized by core biopsy and the diagnosis was confirmed by excisional biopsy

Cloning and characterization of a new laccase from Lactobacillus plantarum J16 CECT 8944 catalyzing biogenic amines degradation.

In our search for degrading activities of biogenic amines (BAs) in lactic acid bacteria, a protein annotated as laccase enzyme was identified in Lactobacillus plantarum J16 (CECT 8944). In this study, the gene of this new laccase was cloned and heterologously overexpressed in Escherichia coli. The recombinant laccase protein was purified and characterized biochemically. The purified laccase showed characteristic spectroscopic properties of blue multicopper oxidases. The enzyme has a molecular weight of ∼ 62.5 kDa and activity toward typical laccase substrates 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,6-dimethoxyphenol (2,6-DMP). The pH optima on ABTS and 2,6-DMP were 3.5 and 7.0, respectively. Kinetic constants Km and Vmax were of 0.21 mM and 0.54 U/mg for ABTS and 1.67 mM and 0.095 U/mg for 2,6-DMP, respectively. The highest oxidizing activity toward 2,6-DMP was obtained at 60 °C. However, after a preincubation step at 85 °C for 10 min, no residual activity was detected. It has been demonstrated that recombinant L. plantarum laccase oxidizes biogenic amines, mainly tyramine, and thus presents new biotechnological potential for the enzyme in eliminating toxic compounds present in fermented food and beverages.

Nanoscale imaging of buried topological defects with quantitative X-ray magnetic microscopy.

Advances in nanoscale magnetism increasingly require characterization tools providing detailed descriptions of magnetic configurations. Magnetic transmission X-ray microscopy produces element specific magnetic domain images with nanometric lateral resolution in films up to ∼100 nm thick. Here we present an imaging method using the angular dependence of magnetic contrast in a series of high resolution transmission X-ray microscopy images to obtain quantitative descriptions of the magnetization (canting angles relative to surface normal and sense). This method is applied to 55-120 nm thick ferromagnetic NdCo5 layers (canting angles between 65° and 22°), and to a NdCo5 film covered with permalloy. Interestingly, permalloy induces a 43° rotation of Co magnetization towards surface normal. Our method allows identifying complex topological defects (merons or ½ skyrmions) in a NdCo5 film that are only partially replicated by the permalloy overlayer. These results open possibilities for the characterization of deeply buried magnetic topological defects, nanostructures and devices.

Theoretical studies of the hydrolysis of antibiotics catalyzed by a metallo-ß-lactamase.

In this paper, hybrid QM/MM molecular dynamics (MD) simulations have been performed to explore the mechanisms of hydrolysis of two antibiotics, Imipenen (IMI), an antibiotic belonging to the subgroup of carbapenems, and the Cefotaxime (CEF), a third-generation cephalosporin antibiotic, in the active site of a mono-nuclear ß-lactamase, CphA from Aeromonas hydrophila. Significant different transition state structures are obtained for the hydrolysis of both antibiotics: while the TS of the CEF is an ionic species with negative charge on nitrogen, the IMI TS presents a tetrahedral-like character with negative charge on oxygen atom of the carbonyl group of the lactam ring. Thus, dramatic conformational changes can take place in the cavity of CphA to accommodate different substrates, which would be the origin of its substrate promiscuity. Since CphA shows only activity against carbapenem antibiotic, this study sheds some light into the origin of the selectivity of the different MbL and, as a consequence, into the discovery of specific and potent MßL inhibitors against a broad spectrum of bacterial pathogens. We have finally probed that a re-parametrization of semiempirical methods should be done to properly describe the behavior the metal cation in active site, Zn(2+), when used in QM/MM calculations.

Quiste de inclusión epidérmica gigante de localización mamaria / Large epidermoid cyst of the breast

Epidermoid cysts are located mainly in the subcutaneous tissue of the trunk andare usually small and asymptomatic. Localization in the breast parenchyma is rare and these cysts may become malignant. We report the case of a 23-year-old breastfeeding woman who presented with a lump protruding from her right breast that grew to more than 10 cm. The diagnosis of epidermal inclusion cyst was confirmed by the pathological examination. Although distinguishing between an epidermoid cyst and a malignant tumor can sometimes be difficult, surgical excision is justified because these cysts can undergo malignant transformation. We discuss images of the breast and surgical specimen of this case and review the literature on the topic

Los quistes epidérmicos se localizan principalmente en el tejido subcutáneo del tronco, y generalmente son pequeños y asintomáticos. Es rara su localización en el parénquima mamario y pueden ser el origen de un proceso patológico maligno. Presentamos el caso de una mujer de 23 años en periodo de lactancia, que consulta por presentar una tumoración grande que protruye en la cubierta cutánea mamaria derecha, alcanzando un tamaño superior a 10 cm. El estudio anatomopatológico confirmó el diagnóstico de quiste de inclusión epidérmica. Aunque a veces el quiste epidérmico es difícil de distinguir de un tumor maligno, la resección quirúrgica está justificada debido a su potencial de malignidad. Se presenta la iconografía de la mama, los especímenes quirúrgicos y se revisa la literatura

Molecular characterization of 39 de novo sSMC: contribution to prognosis and genetic counselling, a prospective study.

Small supernumerary marker chromosomes (sSMCs) are structurally abnormal chromosomes that cannot be characterized by karyotype. In many prenatal cases of de novo sSMC, the outcome of pregnancy is difficult to predict because the euchromatin content is unclear. This study aimed to determine the presence or absence of euchromatin material of 39 de novo prenatally ascertained sSMC by array-comparative genomic hybridization (array-CGH) or single nucleotide polymorphism (SNP) array. Cases were prospectively ascertained from the study of 65,000 prenatal samples [0.060%; 95% confidence interval (CI), 0.042-0.082]. Array-CGH showed that 22 markers were derived from non-acrocentric markers (56.4%) and 7 from acrocentic markers (18%). The 10 additional cases remained unidentified (25.6%), but 7 of 10 could be further identified using fluorescence in situ hybridization; 69% of de novo sSMC contained euchromatin material, 95.4% of which for non-acrocentric markers. Some sSMC containing euchromatin had a normal phenotype (31% for non-acrocentric and 75% for acrocentric markers). Statistical differences between normal and abnormal phenotypes were shown for the size of the euchromatin material (more or less than 1 Mb, p = 0.0006) and number of genes (more or less than 10, p = 0.0009). This study is the largest to date and shows the utility of array-CGH or SNP array in the detection and characterization of de novo sSMC in a prenatal context.

Identification of a novel enzymatic activity from lactic acid bacteria able to degrade biogenic amines in wine.

The main objectives of this study were the search for enzymatic activities responsible for biogenic amine (BA) degradation in lactic acid bacteria (LAB) strains isolated from wine, their identification, and the evaluation of their applicability for reducing BAs in wine. Fifty-three percent of the 76 LAB cell extracts showed activity against a mixture of histamine, tyramine, and putrescine when analyzed in-gel. The quantification of the degrading ability for each individual amine was tested in a synthetic medium and wine. Most of the bacteria analyzed were able to degrade the three amines in both conditions. The highest percentages of degradation in wine were those of putrescine: up to 41% diminution in 1 week. Enzymes responsible for amine degradation were isolated and purified from Lactobacillus plantarum J16 and Pediococcus acidilactici CECT 5930 strains and were identified as multicopper oxidases. This is the first report of an efficient BA reduction in wine by LAB. Furthermore, the identity of the enzymes involved has been revealed.

Novel surface-based methodologies for investigating GH11 xylanase-lignin derivative interactions.

The recalcitrance of lignocellulose to bioprocessing represents the core problem and remains the limiting factor in creating an economy based on lignocellulosic ethanol production. Lignin is responsible for unproductive interactions with enzymes, and understanding how lignin impairs the susceptibility of biomass to enzymatic hydrolysis represents a significant aim in optimising the biological deconstruction of lignocellulose. The objective of this study was to develop methodologies based on surface plasmon resonance (SPR), which provide novel insights into the interactions between xylanase (Tx-xyn11) and phenolic compounds or lignin oligomers. In a first approach, Tx-xyn11 was fixed onto sensor surfaces, and phenolic molecules were applied in the liquid phase. The results demonstrated weak affinity and over-stoichiometric binding, as several phenolic molecules bound to each xylanase molecule. This approach, requiring the use of soluble molecules in the liquid phase, is not applicable to insoluble lignin oligomers, such as the dehydrogenation polymer (DHP). An alternative approach was developed in which a lignin oligomer was fixed onto a sensor surface. Due to their hydrophobic properties, the preparation of stable lignin layers on the sensor surfaces represented a considerable challenge. Among the various chemical and physico-chemical approaches assayed, two approaches (physisorption via the Langmuir-Blodgett technique onto self-assembled monolayer (SAM)-modified gold and covalent coupling to a carboxylated dextran matrix) led to stable lignin layers, which allowed the study of its interactions with Tx-xyn11 in the liquid phase. Our results indicated the presence of weak and non-specific interactions between Tx-xyn11 and DHP.

HMGB1 mediates splenomegaly and expansion of splenic CD11b+ Ly-6C(high) inflammatory monocytes in murine sepsis survivors.

BACKGROUND: More than 500,000 hospitalized patients survive severe sepsis annually in the USA. Recent epidemiological evidence, however, demonstrated that these survivors have significant morbidity and mortality, with 3-year fatality rates higher than 70%. To investigate the mechanisms underlying persistent functional impairment in sepsis survivors, here we developed a model to study severe sepsis survivors following cecal ligation and puncture (CLP). METHODS: Sepsis was induced in mice by CLP and survivors were followed for twelve weeks. Spleen and blood were collected and analyzed at different time points post-sepsis. RESULTS: We observed that sepsis survivors developed significant splenomegaly. Analysis of the splenic cellular compartments revealed a major expansion of the inflammatory CD11b+ Ly-6CHigh pool. Serum high-mobility group box 1 (HMGB1) levels in the sepsis surviving mice were significantly elevated for 4-6 weeks after post-sepsis, and administration of an anti-HMGB1 monoclonal antibody significantly attenuated splenomegaly as well as splenocyte priming. Administration of recombinant HMGB1 to naive mice induced similar splenomegaly, leukocytosis and splenocyte priming as observed in sepsis survivors. Interestingly analysis of circulating HMGB1 from sepsis survivors by mass spectroscopy demonstrated a stepwise increase of reduced form of HMGB1 (with known chemo-attractant properties) during the first 3 weeks, followed by disulphide form (with known inflammatory properties) 4-8 weeks after CLP. DISCUSSION: Our results indicate that prolonged elevation of HMGB1 is a necessary and sufficient mediator of splenomegaly and splenocyte expansion, as well as splenocyte inflammatory priming in murine severe sepsis survivors.

Traumatic epidural retroclival hematoma with odontoid fracture and cardiorespiratory arrest.

STUDY DESIGN: Case report. OBJECTIVES: To describe a case or traumatic retroclival hematoma with features not previously reported. SETTING: Single center. METHODS: Description of a case, in the context of relevant literature on the subject. RESULTS: Traumatic retroclival hematomas are a rare, typically pediatric, entity. Only four cases of epidural hematoma in adult patients have been reported. We describe an additional case, the first with a fatal course in the acute setting. It is also the first retroclival hematoma associated to an odontoid base fracture. CONCLUSION: Retroclival hematomas are a rare diagnosis, to be considered in pediatric patients with flexion-extension, high-energy injuries. Morphology is typically epidural. Brain stem and cranial nerve symptoms are typical. Treatment is usually conservative. Outcome is regarded as favorable, with partial recovery and neurologic sequelae. Adult cases are extremely rare. The case we describe adds new characteristics to the scarcity of cases.

Análisis de la productividad e impacto científico de la pediatría española (2006-2010) / Analysis of the scientific productivity and impact of Spanish paediatrics (2006-2010)

Introducción: El objetivo de este trabajo es cuantificar mediante indicadores bibliométricos la productividad científica de los investigadores e instituciones españolas que publican en revistas pediátricas nacionales y extranjeras, y en revistas multidisciplinares o de otras disciplinas o áreas del conocimiento, durante el quinquenio 2006-2010, así como determinar su repercusión o impacto. Método: Los trabajos objeto de estudio se han obtenido de las bases de datos Science Citation Index Expanded, Scopus, Índice Médico Español e Índice Bibliográfico Español en Ciencias de la Salud, aplicando perfiles de búsqueda específicos. Resultados: Se publicaron 7.971 artículos en 971 revistas, de las que 142 eran españolas y 829 extranjeras, siendo las más productivas Anales de Pediatría (n=1.257), Acta Pediátrica Española (n=456) y Evidencias en Pediatría (n=358). Los artículos se han publicado mayoritariamente en inglés (41,04%) y en español (38,18%), participando 17.874 autores diferentes, procedentes de 3.302 instituciones. El 60,19% de los artículos han sido citados al menos una vez y el 39,81%, ninguna. La media del número de citas recibidas por documento ha sido de 4,28 (DS=9,54). Las revistas más citadas han sido Pediatrics (n=770), Pediatric Infectious Disease Journal y Journal of Clinical Endocrinology and Metabolism (n=553). Discusión: El número de artículos ha aumentado progresivamente desde 2006 hasta 2010, lo que confirma la consolidación y el crecimiento de la investigación pediátrica española, cuyos resultados se publican en una amplia serie de revistas españolas y extranjeras de impacto, entre las que destaca Anales de Pediatría , única revista española pediátrica con factor de impacto. También se confirma la creciente internacionalización de la pediatría española, pues se ha observado un incremento sostenido de los artículos publicados en revistas extranjeras, de los que una cuarta parte se publicaron en revistas estadounidenses o británicas, así como la importancia de la publicación en inglés. Es preocupante el hecho de que casi el 40% de los artículos no hayan recibido ninguna cita, circunstancia que debería alentar a los autores a realizar investigación de calidad y a los editores a poner en práctica políticas editoriales destinadas a aumentar la calidad de los manuscritos y de las revistas (AU)

Introduction: The aim of this paper is to quantify, by means of bibliometric indicators, the scientific production of Spanish researchers and institutions publishing in national and international paediatric journals, as well as multidisciplinary and other knowledge areas publications during the period 2006-2010, and to determine their impact. Methods: The articles were obtained by applying specific search strategies in databases including, Science Citation Index-Expanded, Scopus, Índice Médico Español, and Índice Bibliográfico Español en Ciencias de la Salud. Results: A total of 7971 articles were published in 971 journals, in which 142 were from Spain and 829 were international. The most productive journals were Anales de Pediatría (n=1257), Acta Pediátrica Española (n=456) and Evidencias en Pediatría (n=358). Articles were published mostly in English (41.04%) and in Spanish (38.18%), with the participation of 17 874 different authors from 3302 institutions. Approximately 60% of the papers were cited at least once, and 39.81% were never cited. The mean number of citations per document was 4.28 (SD=9.54). The most cited journals were Pediatrics (n=770), Pediatric Infectious Disease Journal, and Journal of Clinical Endocrinology and Metabolism (n=553). Discussion: The number of articles progressively increased from 2006 to 2010, which confirms the consolidation and growth of Spanish pediatric research, where the results are published in a wide range of Spanish and international journals, among which stands out is the Anales de Pediatría , the only Spanish pediatric journal with an impact factor. The increasing internationalization of Spanish Pediatrics is also confirmed, since a sustained growth of articles published in international journals is observed, where a quarter was published in US or British journals, as well as the importance of the publication in English. There is a concern about the fact that almost 40% of the articles did not receive a citation, which should encourage authors to complete research of quality, and editors to start editorial policies addressed to increase manuscript and journal quality (AU)