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1.
Phys Rev Lett ; 133(5): 052702, 2024 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-39159101

RESUMEN

Asymptotic giant branch stars are responsible for the production of most of the heavy isotopes beyond Sr observed in the solar system. Among them, isotopes shielded from the r-process contribution by their stable isobars are defined as s-only nuclei. For a long time the abundance of ^{204}Pb, the heaviest s-only isotope, has been a topic of debate because state-of-the-art stellar models appeared to systematically underestimate its solar abundance. Besides the impact of uncertainties from stellar models and galactic chemical evolution simulations, this discrepancy was further obscured by rather divergent theoretical estimates for the neutron capture cross section of its radioactive precursor in the neutron-capture flow, ^{204}Tl (t_{1/2}=3.78 yr), and by the lack of experimental data on this reaction. We present the first ever neutron capture measurement on ^{204}Tl, conducted at the CERN neutron time-of-flight facility n_TOF, employing a sample of only 9 mg of ^{204}Tl produced at the Institute Laue Langevin high flux reactor. By complementing our new results with semiempirical calculations we obtained, at the s-process temperatures of kT≈8 keV and kT≈30 keV, Maxwellian-averaged cross sections (MACS) of 580(168) mb and 260(90) mb, respectively. These figures are about 3% lower and 20% higher than the corresponding values widely used in astrophysical calculations, which were based only on theoretical calculations. By using the new ^{204}Tl MACS, the uncertainty arising from the ^{204}Tl(n,γ) cross section on the s-process abundance of ^{204}Pb has been reduced from ∼30% down to +8%/-6%, and the s-process calculations are in agreement with the latest solar system abundance of ^{204}Pb reported by K. Lodders in 2021.

2.
Phys Rev Lett ; 132(12): 122701, 2024 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-38579210

RESUMEN

^{140}Ce(n,γ) is a key reaction for slow neutron-capture (s-process) nucleosynthesis due to being a bottleneck in the reaction flow. For this reason, it was measured with high accuracy (uncertainty ≈5%) at the n_TOF facility, with an unprecedented combination of a high purity sample and low neutron-sensitivity detectors. The measured Maxwellian averaged cross section is up to 40% higher than previously accepted values. Stellar model calculations indicate a reduction around 20% of the s-process contribution to the Galactic cerium abundance and smaller sizeable differences for most of the heavier elements. No variations are found in the nucleosynthesis from massive stars.

3.
Eur Phys J A Hadron Nucl ; 58(12): 239, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36514540

RESUMEN

Neutron capture reaction cross sections on 74 Ge are of importance to determine 74 Ge production during the astrophysical slow neutron capture process. We present new resonance data on 74 Ge( n , γ ) reactions below 70 keV neutron energy. We calculate Maxwellian averaged cross sections, combining our data below 70 keV with evaluated cross sections at higher neutron energies. Our stellar cross sections are in agreement with a previous activation measurement performed at Forschungszentrum Karlsruhe by Marganiec et al., once their data has been re-normalised to account for an update in the reference cross section used in that experiment.

5.
Phys Rev Lett ; 129(1): 012501, 2022 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-35841541

RESUMEN

A narrow near-threshold proton-emitting resonance (E_{x}=11.4 MeV, J^{π}=1/2^{+}, and Γ_{p}=4.4 keV) was directly observed in ^{11}B via proton resonance scattering. This resonance was previously inferred in the ß-delayed proton emission of the neutron halo nucleus ^{11}Be. The good agreement between both experimental results serves as a ground to confirm the existence of such exotic decay and the particular behavior of weakly bound nuclei coupled to the continuum. R-matrix analysis shows a sizable partial decay width for both, proton and α (Γ_{α}=11 keV) emission channels.

6.
Nature ; 606(7915): 678-682, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35732764

RESUMEN

A long-standing question in nuclear physics is whether chargeless nuclear systems can exist. To our knowledge, only neutron stars represent near-pure neutron systems, where neutrons are squeezed together by the gravitational force to very high densities. The experimental search for isolated multi-neutron systems has been an ongoing quest for several decades1, with a particular focus on the four-neutron system called the tetraneutron, resulting in only a few indications of its existence so far2-4, leaving the tetraneutron an elusive nuclear system for six decades. Here we report on the observation of a resonance-like structure near threshold in the four-neutron system that is consistent with a quasi-bound tetraneutron state existing for a very short time. The measured energy and width of this state provide a key benchmark for our understanding of the nuclear force. The use of an experimental approach based on a knockout reaction at large momentum transfer with a radioactive high-energy 8He beam was key.

7.
Neurologia (Engl Ed) ; 37(2): 110-121, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35279225

RESUMEN

INTRODUCTION: Neuroinflammation is involved in the pathophysiology of various neurological disorders, in particular Alzheimer disease (AD) and Parkinson's disease (PD). Alterations in the blood-brain barrier may allow peripheral blood lymphocytes to enter the central nervous system; these may participate in disease pathogenesis. OBJECTIVE: To evaluate the peripheral blood lymphocyte profiles of patients with AD and PD and their association with the disease and its progression. METHODS: The study included 20 patients with AD, 20 with PD, and a group of healthy individuals. Ten of the patients with AD and 12 of those with PD were evaluated a second time 17 to 27 months after the start of the study. Lymphocyte subpopulations and their activation status were determined by flow cytometry. All patients underwent neurological examinations using internationally validated scales. RESULTS: Compared to healthy individuals, patients with AD and PD showed significantly higher levels of activated lymphocytes, lymphocytes susceptible to apoptosis, central memory T cells, and regulatory T and B cells. As the diseases progressed, there was a significant decrease in activated cells (CD4+ CD38+ and CD8+ CD38+ in PD and AD, CD4+ CD69+ and CD8+ CD69+ in PD), T cells susceptible to apoptosis, and some regulatory populations (CD19+ CD5+ IL10+ in PD and AD, CD19+ CD5+ IL10+ FoxP3+, CD4+ FoxP3+ CD25+ CD45RO+ in PD). In patients with AD, disease progression was associated with lower percentages of CD4+ CD38+ cells and higher percentages of effector CD4 cells at the beginning of the study. Significant differences were observed between both diseases. CONCLUSIONS: This study provides evidence of changes in peripheral blood lymphocyte phenotypes associated with AD and PD and their severity. Considering effective blood-brain communication, our results open new avenues of research into immunomodulation therapies to treat these diseases.


Asunto(s)
Enfermedad de Alzheimer , Enfermedad de Parkinson , Linfocitos T CD4-Positivos , Citometría de Flujo , Humanos , Fenotipo
8.
Neurología (Barc., Ed. impr.) ; 37(2): 110-121, Mar. 2022. tab, graf
Artículo en Inglés, Español | IBECS | ID: ibc-204646

RESUMEN

Introducción: La neuroinflamación está involucrada en la fisiopatología de diferentes trastornos neurológicos, en particular la enfermedad de Alzheimer (EA) y la enfermedad de Parkinson (EP). Las alteraciones en la barrera hematoencefálica pueden permitir la entrada al sistema nervioso central de linfocitos periféricos, los cuales pueden participar en la patología de las enfermedades. Objetivo: Evaluar el perfil de linfocitos periféricos en pacientes con EA y EP y su asociación con la enfermedad y su progresión. Métodos: Se incluyeron 20 pacientes con EA, 20 pacientes con EP y un grupo de individuos sanos. Diez de los pacientes con EA y 12 de los pacientes con EP fueron evaluados una segunda vez de 17 a 27 meses después del inicio del estudio. Las subpoblaciones de linfocitos y su estado de activación se determinaron mediante citometría de flujo. Todos los pacientes fueron evaluados neurológicamente utilizando escalas validadas internacionalmente. Resultados: Los pacientes con EA y EP mostraron un aumento significativo en los niveles de linfocitos activados, linfocitos susceptibles a la apoptosis, células T de memoria central y células T y B reguladoras con respecto a los sujetos sanos. A medida que las enfermedades progresaron se observó una disminución significativa de las células activadas (CD4+ CD38+ y CD8+ CD38+ en EP y EA; CD4+ CD69+ y CD8+ CD69+ en EP), de las células T susceptibles a la apoptosis y de algunas poblaciones reguladoras (CD19+ CD5+ IL10+ en EP y EA; CD19+ CD5+ IL10+ FoxP3+, CD4+ FoxP3+ CD25+ CD45RO+ en EP). En pacientes con EA la progresión de la enfermedad se asoció con porcentajes más bajos de CD4 + CD38 + y mayores porcentajes de células CD4 efectoras al comienzo del estudio. Se observaron diferencias significativas entre ambas enfermedades. Conclusiones: Este estudio proporciona evidencia de cambios en los fenotipos de linfocitos periféricos asociados a EA y EP y a su gravedad. [...] (AU)


Introduction: Neuroinflammation is involved in the pathophysiology of various neurological disorders, in particular Alzheimer disease (AD) and Parkinson's disease (PD). Alterations in the blood-brain barrier may allow peripheral blood lymphocytes to enter the central nervous system; these may participate in disease pathogenesis. Objective: To evaluate the peripheral blood lymphocyte profiles of patients with AD and PD and their association with the disease and its progression. Methods: The study included 20 patients with AD, 20 with PD, and a group of healthy individuals. Ten of the patients with AD and 12 of those with PD were evaluated a second time 17 to 27 months after the start of the study. Lymphocyte subpopulations and their activation status were determined by flow cytometry. All patients underwent neurological examinations using internationally validated scales. Results: Compared to healthy individuals, patients with AD and PD showed significantly higher levels of activated lymphocytes, lymphocytes susceptible to apoptosis, central memory T cells, and regulatory T and B cells. As the diseases progressed, there was a significant decrease in activated cells (CD4+ CD38+ and CD8+ CD38 + in PD and AD, CD4+ CD69+ and CD8+ CD69+ in PD), T cells susceptible to apoptosis, and some regulatory populations (CD19+ CD5+ IL10+ in PD and AD, CD19+ CD5+ IL10+ FoxP3+, CD4+ FoxP3+ CD25+ CD45RO+ in PD). In patients with AD, disease progression was associated with lower percentages of CD4+ CD38+ cells and higher percentages of effector CD4 cells at the beginning of the study. Significant differences were observed between both diseases. Conclusions: This study provides evidence of changes in peripheral blood lymphocyte phenotypes associated with AD and PD and their severity. Considering effective blood-brain communication, our results open new avenues of research into immunomodulation therapies to treat these diseases. (AU)


Asunto(s)
Humanos , Masculino , Femenino , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer , Enfermedad de Parkinson , Fenotipo , Linfocitos T CD4-Positivos , Citometría de Flujo , Degeneración Nerviosa , Inflamación
9.
Eur Rev Med Pharmacol Sci ; 25(19): 5942-5946, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34661253

RESUMEN

OBJECTIVE: The pandemic disease by SARS-CoV-2 infection does not have an effective treatment. To prevent the disease, scientists developed vaccines that the clinicians use as an emergency licensed vaccine. The objective of this study was to determine the side effects in personnel vaccinated at the Military Central Hospital of Mexico with the BNT162b2 vaccine. PATIENTS AND METHODS: This study included the subjects who had received both doses of the BNT162b2 vaccine between December 2020 and February 2021. We asked about the side effects after the first and the second vaccine doses. One group had no history of COVID-19, and the second had a history of COVID-19. ANTI-SARS-CoV-2 antibodies were measured by the immunodetection technique in the second group only. RESULTS: We included 946 participants, 62% were women, and 80% were without comorbidities; 680 were included in the first group, and only 266 were in the second group. After the first dose, 77% of the first group and 86% of the second group presented some side effects. After the second dose, 84% of the first group and 89% of the second group showed some side effects. The main side effect was mild pain. All participants (126) were IgG positive, and only 26.9% were IgM positive at 17.5 days (12.8 days, 20.3 days) after the second dose. CONCLUSIONS: There is a positive correlation between side effects after the first dose in patients with a history of previous SARS-CoV-2 infection compared to those who did not. Nevertheless, this correlation is not present after the second dose. The low percentage of IgM could be related to the time interval between vaccination and sample measure.


Asunto(s)
Vacunas contra la COVID-19/efectos adversos , Hospitales Militares/estadística & datos numéricos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Vacuna BNT162 , COVID-19/complicaciones , COVID-19/diagnóstico , Vacunas contra la COVID-19/administración & dosificación , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Femenino , Humanos , Inmunoglobulina G/análisis , Inmunoglobulina M/análisis , Masculino , México , Persona de Mediana Edad , Personal Militar , Adulto Joven
10.
Nat Commun ; 12(1): 4805, 2021 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-34376669

RESUMEN

Proton radioactivity was discovered exactly 50 years ago. First, this nuclear decay mode sets the limit of existence on the nuclear landscape on the neutron-deficient side. Second, it comprises fundamental aspects of both quantum tunnelling as well as the coupling of (quasi)bound quantum states with the continuum in mesoscopic systems such as the atomic nucleus. Theoretical approaches can start either from bound-state nuclear shell-model theory or from resonance scattering. Thus, proton-radioactivity guides merging these types of theoretical approaches, which is of broader relevance for any few-body quantum system. Here, we report experimental measurements of proton-emission branches from an isomeric state in 54mNi, which were visualized in four dimensions in a newly developed detector. We show that these decays, which carry an unusually high angular momentum, ℓ = 5 and ℓ = 7, respectively, can be approximated theoretically with a potential model for the proton barrier penetration and a shell-model calculation for the overlap of the initial and final wave functions.

11.
Rev Esp Anestesiol Reanim (Engl Ed) ; 68(1): 10-20, 2021 Jan.
Artículo en Inglés, Español | MEDLINE | ID: mdl-33077309

RESUMEN

BACKGROUND AND OBJECTIVES: There are limited information on outcome, complications and treatments of critically ill COVID-19 patients requiring admission to an intensive care unit (ICU). The aim of this study is to describe the clinical ICU course, treatments used, complications and outcomes, of critically ill COVID-19 patients admitted in seven ICU in Galicia region during the 2020 March-April pandemic peak. METHODS: Between March 21 and April 19, 2020, we evaluated critically ill COVID-19 patients admitted to the ICU of Anesthesia of seven hospitals in Galicia, northwestern Spain. Outcome, complications, and treatments were monitored until May 6, 2020, the final date of follow-up. RESULTS: A total of 97 critically ill COVID-19 patients were included. During ICU stay, mechanical ventilation became necessary in 80 (82.5%) patients, and tracheostomy in 22 (22.7%) patients. Prone position was used frequently in both intubated (67.5%) and awake (27.8%) patients. Medications consisted of antivirals agents (92.7%), corticosteroids (93.8%), tocilizumab (57.7%), and intermediate or high doses of anticoagulants (83.5%). The most frequent complications were ICU-acquired infection (52.6%), thrombosis events (16.5%), and reintubation (9.3%). After a median follow-up of 42 (34-45) days, 15 patients (15.5%) deceased, 73 patients (75.2%) had been discharged from ICU, and nine patients (9.3%) were still in the ICU. CONCLUSIONS: A high proportion of our critically ill COVID-19 patients required mechanical ventilation, prone positioning, antiviral medication, corticosteroids, and anticoagulants. ICU complications were frequent, mainly infections and thrombotic events. We had a relatively low mortality of 15,5%.


Asunto(s)
Anestesia , COVID-19 , Anciano , COVID-19/complicaciones , COVID-19/terapia , Cuidados Críticos , Enfermedad Crítica , Femenino , Humanos , Unidades de Cuidados Intensivos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , España
12.
Phys Rev Lett ; 124(20): 202502, 2020 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-32501052

RESUMEN

Taking benefit of the R3B/SOFIA setup to measure the mass and the nuclear charge of both fission fragments in coincidence with the total prompt-neutron multiplicity, the scission configurations are inferred along the thorium chain, from the asymmetric fission in the heavier isotopes to the symmetric fission in the neutron-deficient thorium. Against all expectations, the symmetric scission in the light thorium isotopes shows a compact configuration, which is in total contrast to what is known in the fission of the heavier thorium isotopes and heavier actinides. This new main symmetric scission mode is characterized by a significant drop in deformation energy of the fission fragments of about 19 MeV, compared to the well-known symmetric scission in the uranium-plutonium region.

13.
Phys Rev Lett ; 123(9): 092503, 2019 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-31524478

RESUMEN

A direct and complete measurement of isotopic fission-fragment yields of ^{239}U has been performed for the first time. The ^{239}U fissioning system was produced with an average excitation energy of 8.3 MeV in one-neutron transfer reactions between a ^{238}U beam and a ^{9}Be target at Coulomb barrier energies. The fission fragments were detected and isotopically identified using the VAMOS++ spectrometer at the GANIL facility. The measurement allows us to directly evaluate the fission models at excitation energies of fast neutrons, which are relevant for next-generation nuclear reactors. The present data, in agreement with model calculations, do not support the recently reported anomaly in the fission-fragment yields of ^{239}U, and they confirm the persistence of spherical shell effects in the Sn region at excitation energies exceeding the fission barrier by a few mega-electron volts.

14.
Sci Rep ; 9(1): 6422, 2019 04 23.
Artículo en Inglés | MEDLINE | ID: mdl-31015496

RESUMEN

Storing large amounts of organic carbon, soils are a key but uncertain component of the global carbon cycle, and accordingly, of Earth System Models (ESMs). Soil organic carbon (SOC) dynamics are regulated by a complex interplay of drivers. Climate, generally represented by temperature and moisture, is regarded as one of the fundamental controls. Here, we use 54 forest sites in Switzerland, systematically selected to span near-independent gradients in temperature and moisture, to disentangle the effects of climate, soil properties, and landform on SOC dynamics. We estimated two SOC turnover times, based on bulk soil 14C measurements (τ14C) and on a 6-month laboratory soil incubation (τi). In addition, upon incubation, we measured the 14C signature of the CO2 evolved and quantified the cumulated production of dissolved organic carbon (DOC). Our results demonstrate that τi and τ14C capture the dynamics of contrasting fractions of the SOC continuum. The 14C-based τ14C primarily reflects the dynamics of an older, stabilised pool, whereas the incubation-based τi mainly captures fresh readily available SOC. Mean site temperature did not raise as a critical driver of SOC dynamics, and site moisture was only significant for τi. However, soil pH emerged as a key control of both turnover times. The production of DOC was independent of τi and not driven by climate, but primarily by the content of clay and, secondarily by the slope of the site. At the regional scale, soil physicochemical properties and landform appear to override the effect of climate on SOC dynamics.

15.
Neurologia (Engl Ed) ; 2019 Mar 11.
Artículo en Inglés, Español | MEDLINE | ID: mdl-30871733

RESUMEN

INTRODUCTION: Neuroinflammation is involved in the pathophysiology of various neurological disorders, in particular Alzheimer disease (AD) and Parkinson's disease (PD). Alterations in the blood-brain barrier may allow peripheral blood lymphocytes to enter the central nervous system; these may participate in disease pathogenesis. OBJECTIVE: To evaluate the peripheral blood lymphocyte profiles of patients with AD and PD and their association with the disease and its progression. METHODS: The study included 20 patients with AD, 20 with PD, and a group of healthy individuals. Ten of the patients with AD and 12 of those with PD were evaluated a second time 17 to 27 months after the start of the study. Lymphocyte subpopulations and their activation status were determined by flow cytometry. All patients underwent neurological examinations using internationally validated scales. RESULTS: Compared to healthy individuals, patients with AD and PD showed significantly higher levels of activated lymphocytes, lymphocytes susceptible to apoptosis, central memory T cells, and regulatory T and B cells. As the diseases progressed, there was a significant decrease in activated cells (CD4+ CD38+ and CD8+ CD38 + in PD and AD, CD4+ CD69+ and CD8+ CD69+ in PD), T cells susceptible to apoptosis, and some regulatory populations (CD19+ CD5+ IL10+ in PD and AD, CD19+ CD5+ IL10+ FoxP3+, CD4+ FoxP3+ CD25+ CD45RO+ in PD). In patients with AD, disease progression was associated with lower percentages of CD4+ CD38+ cells and higher percentages of effector CD4 cells at the beginning of the study. Significant differences were observed between both diseases. CONCLUSIONS: This study provides evidence of changes in peripheral blood lymphocyte phenotypes associated with AD and PD and their severity. Considering effective blood-brain communication, our results open new avenues of research into immunomodulation therapies to treat these diseases.

16.
J Plant Res ; 132(1): 3-17, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30552526

RESUMEN

We provide here the first full chloroplast genome sequence, i.e., the plastome, for a species belonging to the fern order Hymenophyllales. The phylogenetic position of this order within leptosporangiate ferns, together with the general scarcity of information about fern plastomes, places this research as a valuable study on the analysis of the diversity of plastomes throughout fern evolution. Gene content of V. speciosa plastome was similar to that in most ferns, although there were some characteristic gene losses and lineage-specific differences. In addition, an important number of genes required U to C RNA editing for proper protein translation and two genes showed start codons alternative to the canonical AUG (AUA). Concerning gene order, V. speciosa shared the specific 30-kb inversion of euphyllophytes plastomes and the 3.3-kb inversion of fern plastomes, keeping the ancestral gene order shared by eusporangiate and early leptosporangiate ferns. Conversely, V. speciosa has expanded IR regions comprising the rps7, rps12, ndhB and trnL genes in addition to rRNA and other tRNA genes, a condition shared with several eusporangiate ferns, lycophytes and hornworts, as well as most seed plants.


Asunto(s)
Evolución Molecular , Helechos/genética , Genoma del Cloroplasto , Genoma de Planta , Filogenia , Análisis de Secuencia de ADN
17.
Int Endod J ; 52(3): 297-306, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30168851

RESUMEN

Previous studies have found an association between the outcome of root canal treatment (RCT) and diabetic status. This systematic review and meta-analysis aimed to analyse the potential relationship between diabetes and the occurrence of extracted root filled teeth (RFT). The clinical PICO question was as follows: in adult patients with RFT, does the absence or presence of diabetes influence the prevalence of RFT extraction? The key words used in the systematic search were as follows: (Diabetes OR Diabetes Mellitus OR Hyperglycaemia OR Diabetic) AND (Endodontic OR Endodontics OR Endodontic Treatment OR Root Canal Treatment OR Root Canal Preparation OR Root Canal Therapy OR Root Filled Teeth OR Endodontically Treated Teeth) AND (Extraction OR Retention OR Survival OR Success OR Failure OR Outcome). The primary outcome variable was odds ratio (OR) for the frequency of extracted RFT in diabetics and healthy subjects. The method of DerSimonian-Laird with random effects was used to calculate the overall OR. Three hundred titles were identified, and three studies achieved the inclusion criteria. Data from 54 936 root canal treatments, 50 301 in nondiabetic control subjects and 4635 in diabetic patients, were analysed. The calculated overall odds ratio (OR = 2.44; 95% CI = 1.54-3.88; P = 0.0001) implies that diabetics had a significantly higher prevalence of extracted RFT than healthy nondiabetic subjects. The results of available studies indicate a significant relationship between DM and increased frequency of nonretained root filled teeth. Diabetes mellitus should be considered an important preoperative prognostic factor in root canal treatment.


Asunto(s)
Diabetes Mellitus , Periodontitis Periapical/complicaciones , Periodontitis Periapical/cirugía , Tratamiento del Conducto Radicular , Extracción Dental , Diente no Vital , Adulto , Humanos , Factores de Riesgo
18.
Ann Bot ; 123(4): 587-599, 2019 03 14.
Artículo en Inglés | MEDLINE | ID: mdl-30357311

RESUMEN

BACKGROUND AND AIMS: Vandenboschia speciosa is a highly vulnerable fern species, with a large genome (10.5 Gb). Haploid gametophytes and diploid sporophytes are perennial, can reproduce vegetatively, and certain populations are composed only of independent gametophytes. These features make this fern a good model: (1) for high-throughput analysis of satellite DNA (satDNA) to investigate possible evolutionary trends in satDNA sequence features; (2) to determine the relative contribution of satDNA and other repetitive DNAs to its large genome; and (3) to analyse whether the reproduction mode or phase alternation between long-lasting haploid and diploid stages influences satDNA abundance or divergence. METHODS: We analysed the repetitive fraction of the genome of this species in three different populations (one comprised only of independent gametophytes) using Illumina sequencing and bioinformatic analysis with RepeatExplorer and satMiner. KEY RESULTS: The satellitome of V. speciosa is composed of 11 satDNA families, most of them showing a short repeat length and being A + T rich. Some satDNAs had complex repeats composed of sub-repeats, showing high similarity to shorter satDNAs. Three families had particular structural features and highly conserved motifs. SatDNA only amounts to approx. 0.4 % of its genome. Likewise, microsatellites do not represent more than 2 %, but transposable elements (TEs) represent approx. 50 % of the sporophytic genomes. We found high resemblance in satDNA abundance and divergence between both gametophyte and sporophyte samples from the same population and between populations. CONCLUSIONS: (1) Longer (and older) satellites in V. speciosa have a higher A + T content and evolve from shorter ones and, in some cases, microsatellites were a source of new satDNAs; (2) the satellitome does not explain the huge genome size in this species while TEs are the major repetitive component of the V. speciosa genome and mostly contribute to its large genome; and (3) reproduction mode or phase alternation between gametophytes and sporophytes does not entail accumulation or divergence of satellites.


Asunto(s)
ADN de Plantas/análisis , ADN Satélite/análisis , Evolución Molecular , Helechos/genética , Genoma de Planta , Células Germinativas de las Plantas/fisiología , Secuencia de Bases , Diploidia , Haploidia , Reproducción
19.
Arch. Soc. Esp. Oftalmol ; 92(6): 280-282, jun. 2017. ilus
Artículo en Español | IBECS | ID: ibc-163615

RESUMEN

Casos clínicos: Presentamos 2 casos clínicos de endoftalmitis endógena bacteriana. El primero causado por Streptococcus bovis tras la realización de una colonoscopia, con mala evolución que acabó en evisceración. El segundo debido a un Staphylococcus aureus meticilin resistente procedente de un absceso paraespinal que complicaba una artrodesis, con excelente recuperación visual. Discusión: La endoftalmitis endógena bacteriana es una enfermedad poco frecuente y grave en la que bacterias procedentes de un foco primario llegan por vía sanguínea hasta el ojo. El diagnóstico de sospecha ha de ser lo más precoz posible, basado en la clínica y los antecedentes del paciente. Un tratamiento adecuado y específico con antibióticos intravenosos e intravítreos puede evitar el mal pronóstico visual en algunos casos (AU)


Clinical cases: The cases are presented on 2 patients with bacterial endogenous endophthalmitis. The first one was caused by Streptococcus bovis, developed after colonoscopy, which had a poor outcome and resulted in evisceration. The second case was caused by a methicillin resistant Staphylococcus aureus from an arthrodesis complicated with a para-spinal abscess. It had an excellent visual outcome. Discussion: Bacterial endogenous endophthalmitis is a rare, but serious ocular disease that occurs when bacteria reach the eye via the bloodstream. It requires a very early diagnosis based on the clinical symptoms and patient history. A suitable and specific treatment with intravenous and intravitreal antibiotics may prevent a bad visual prognosis in some cases (AU)


Asunto(s)
Humanos , Masculino , Femenino , Anciano , Endoftalmitis/microbiología , Streptococcus bovis/aislamiento & purificación , Staphylococcus aureus/aislamiento & purificación , Infecciones Bacterianas del Ojo/microbiología , Factores de Riesgo , Antibacterianos/uso terapéutico , Resultado del Tratamiento
20.
J Vet Intern Med ; 31(4): 1202-1208, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28556535

RESUMEN

BACKGROUND: Knowledge of the mineral composition of the causative urolith is important to develop preventative strategies. Advances in analytic techniques have led to detection of urolith components not previously recognized. HYPOTHESIS/OBJECTIVES: The objectives of this study were to characterize uroliths in sheep and goats structurally and clinically. We hypothesized that amorphous magnesium calcium phosphate (AMCP) would be a naturally occurring urolith type in sheep and goats. ANIMALS: Forty-nine sheep and goats presenting for obstructive urolithiasis from June 15, 2014 through June 14, 2016 were reviewed along with the demographic data of all small ruminants admitted during that same period. METHODS: Medical records were reviewed for demographic and historical data, and 36 uroliths obtained from these cases during diagnostic or therapeutic procedures were analyzed by infrared spectroscopy to determine chemical composition. RESULTS: AMCP is a naturally occurring urolith type in obstructed male sheep and goats and was the most common urolith type in this study, where it occurred as a majority component with struvite (39% of uroliths) or as a pure component (11%). Pure struvite was found in 1 urolith (2%). Calcium carbonate was the second most frequent urolith with 31% of uroliths being pure calcium carbonate. CONCLUSIONS AND CLINICAL IMPORTANCE: This study demonstrates that uroliths, which appear consistent with struvite, could actually be calcium-containing AMCP. Urolith analysis is critical in determining mineral content of uroliths to guide dietary recommendations for prevention.


Asunto(s)
Enfermedades de las Cabras/metabolismo , Enfermedades de las Ovejas/metabolismo , Cálculos Urinarios/veterinaria , Urolitiasis/veterinaria , Animales , Fosfatos de Calcio/análisis , Enfermedades de las Cabras/diagnóstico por imagen , Cabras , Magnesio/análisis , Masculino , Radiografía/veterinaria , Ovinos , Enfermedades de las Ovejas/diagnóstico por imagen , Cálculos Urinarios/química , Cálculos Urinarios/diagnóstico por imagen , Urolitiasis/diagnóstico por imagen , Urolitiasis/metabolismo
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