821 research outputs found

    Numerical simulation of dark lanes in post-flare supra-arcade

    Full text link
    We integrate the MHD ideal equations to simulate dark void sunwardly moving structures in post--flare supra--arcades. We study the onset and evolution of the internal plasma instability to compare with observations and to gain insight into physical processes and characteristic parameters of these phenomena. The numerical approach uses a finite-volume Harten-Yee TVD scheme to integrate the 1D1/2 MHD equations specially designed to capture supersonic flow discontinuities. The integration is performed in both directions, the sunward radial one and the transverse to the magnetic field. For the first time, we numerically reproduce observational dark voids described in Verwichte et al. (2005). We show that the dark tracks are plasma vacuums generated by the bouncing and interfering of shocks and expansion waves, upstream an initial slow magnetoacoustic shock produced by a localized deposition of energy modeled with a pressure perturbation. The same pressure perturbation produces a transverse to the field or perpendicular magnetic shock giving rise to nonlinear waves that compose the kink--like plasma void structures, with the same functional sunward decreasing phase speed and constancy with height of the period, as those determined by the observations.Comment: Accepted MNRAS, 6 pages, 7 figure

    A prospective study of the clinical outcomes and prognosis associated with comorbid COPD in the atrial fibrillation population

    Get PDF
    Background: Patients with COPD are at higher risk of presenting with atrial fibrillation (AF). Information about clinical outcomes and optimal medical treatment of AF in the setting of COPD remains missing. We aimed to describe the prevalence of COPD in a sizeable cohort of real-world AF patients belonging to the same healthcare area and to examine the relationship between comorbid COPD and AF prognosis. Methods: Prospective analysis performed in a specific healthcare area. Data were obtained from several sources within the "data warehouse of the Galician Healthcare Service" using multiple analytical tools. Statistical analyses were completed using SPSS 19 and STATA 14.0. Results: A total of 7,990 (2.08%) patients with AF were registered throughout 2013 in our healthcare area (n=348,985). Mean age was 76.83+/-10.51 years and 937 (11.7%) presented with COPD. COPD patients had a higher mean CHA2DS2-VASc (4.21 vs 3.46; P=0.02) and received less beta-blocker and more digoxin therapy than those without COPD. During a mean follow-up of 707+/-103 days, 1,361 patients (17%) died. All-cause mortality was close to two fold higher in the COPD group (28.3% vs 15.5%; P<0.001). Independent predictive factors for all-cause mortality were age, heart failure, diabetes, previous thromboembolic event, dementia, COPD, and oral anticoagulation (OA). There were nonsignificant differences in thromboembolic events (1.7% vs 1.5%; P=0.7), but the rate of hemorrhagic events was significantly higher in the COPD group (3.3% vs 1.9%; P=0.004). Age, valvular AF, OA, and COPD were independent predictive factors for hemorrhagic events. In COPD patients, age, heart failure, vasculopathy, lack of OA, and lack of beta-blocker use were independent predictive factors for all-cause mortality. Conclusion: AF patients with COPD have a higher incidence of adverse events with significantly increased rates of all-cause mortality and hemorrhagic events than AF patients without COPD. However, comorbid COPD was not associated with differences in cardiovascular death or stroke rate. OA and beta-blocker treatment presented a risk reduction in mortality while digoxin use exerted a neutral effect

    Pathogenesis and Clinical Relevance of Candida Biofilms in Vulvovaginal Candidiasis

    Get PDF
    The ability of Candida spp. to form biofilms is crucial for its pathogenicity, and thus, it should be considered an important virulence factor in vulvovaginal candidiasis (VVC) and recurrent VVC (RVVC). Its ability to generate biofilms is multifactorial and is generally believed to depend on the site of infection, species and strain involved, and the microenvironment in which the infection develops. Therefore, both cell surface proteins, such as Hwp1, Als1, and Als2, and the cell wall-related protein, Sun41, play a critical role in the adhesion and virulence of the biofilm. Immunological and pharmacological approaches have identified the NLRP3 inflammasome as a crucial molecular factor contributing to host immunopathology. In this context, we have earlier shown that Candida albicans associated with hyphae-secreted aspartyl proteinases (specifically SAP4-6) contribute to the immunopathology of the disease. Transcriptome profiling has revealed that non-coding transcripts regulate protein synthesis post-transcriptionally, which is important for the growth of Candida spp. Other studies have employed RNA sequencing to identify differences in the 1,245 Candida genes involved in surface and invasive cellular metabolism regulation. In vitro systems allow the simultaneous processing of a large number of samples, making them an ideal screening technique for estimating various physicochemical parameters, testing the activity of antimicrobial agents, and analyzing genes involved in biofilm formation and regulation (in situ) in specific strains. Murine VVC models are used to study C. albicans infection, especially in trials of novel treatments and to understand the cause(s) for resistance to conventional therapeutics. This review on the clinical relevance of Candida biofilms in VVC focuses on important advances in its genomics, transcriptomics, and proteomics. Moreover, recent experiments on the influence of biofilm formation on VVC or RVVC pathogenesis in laboratory animals have been discussed. A clear elucidation of one of the pathogenesis mechanisms employed by Candida biofilms in vulvovaginal candidiasis and its applications in clinical practice represents the most significant contribution of this manuscript

    MitoGenesisDB: an expression data mining tool to explore spatio-temporal dynamics of mitochondrial biogenesis

    Get PDF
    Mitochondria constitute complex and flexible cellular entities, which play crucial roles in normal and pathological cell conditions. The database MitoGenesisDB focuses on the dynamic of mitochondrial protein formation through global mRNA analyses. Three main parameters confer a global view of mitochondrial biogenesis: (i) time-course of mRNA production in highly synchronized yeast cell cultures, (ii) microarray analyses of mRNA localization that define translation sites and (iii) mRNA transcription rate and stability which characterize genes that are more dependent on post-transcriptional regulation processes. MitoGenesisDB integrates and establishes cross-comparisons between these data. Several model organisms can be analyzed via orthologous relationships between interspecies genes. More generally this database supports the ‘post-transcriptional operon’ model, which postulates that eukaryotes co-regulate related mRNAs based on their functional organization in ribonucleoprotein complexes. MitoGenesisDB allows identifying such groups of post-trancriptionally regulated genes and is thus a useful tool to analyze the complex relationships between transcriptional and post-transcriptional regulation processes. The case of respiratory chain assembly factors illustrates this point. The MitoGenesisDB interface is available at http://www.dsimb.inserm.fr/dsimb_tools/mitgene/

    An?lisis documental sobre los trabajos de grado de los estudiantes de Licenciatura en Educaci?n B?sica con ?nfasis en Lengua Castellana, de la Universidad del Tolima en los CREAD a distancia enfatizados en el leguaje

    Get PDF
    65 p. Recurso Electr?nicoEn el presente art?culo se muestra el estado del arte de las investigaciones sobre ?Lenguaje? basadas en los trabajos de grado de los estudiantes de Lengua Castellana con ?nfasis en B?sica Primaria de la Universidad del Tolima. Desde un marco metodol?gico de corte cualitativo-cuantitativo atendiendo a los objetivos propuestos con un estudio de tipo sistematizaci?n y an?lisis, llevando a cabo un rastreo de dicho an?lisis de los trabajos de grado, que comprende los grados entre 3? a 11?. En la educaci?n. Durante el per?odo de tiempo 2009-2015, de trabajos de grado de los CREAD a distancia. Como resultado del an?lisis indican que la l?nea del lenguaje contiene lectura, escritura, lecto-escritura, oralidad, pensamiento cr?tico. Para lo cual la mayor?a de los trabajos de grado los estudiantes seg?n recolecci?n de datos, emplearon la observaci?n, y fueron orientadas desde el enfoque constructivismo (Vygotsky). Adem?s, en los trabajos de grado priman la competencia comunicativa. Se encontraron datos en los cuales los trabajos de grado no poseen dimensi?n alguna.The present article shows the state of the art of the research on "Language" based on the degree works of the students of Spanish Language with emphasis in Primary Basic of the University of Tolima. From a methodological framework of qualitative-quantitative cut taking into account the objectives proposed with a study of type systematization and analysis, carrying out a tracing of said analysis of the works of degree, that includes the grades between 3? to 11?. In education. During the 2009-2015 time period, of distance CREAD degree works. As a result of the analysis indicate that the language line contains reading, writing, reading-writing, orality, critical thinking. For which most of the grade-level students the students based on data collection, used observation, and were oriented from the constructivism approach (Vygotsky). In addition, in the works of degree prevail the communicative competence. Data were found in which grade work does not have any dimension. Keywords: Analysis, Qualitative, quantitative, data, language, systematization

    Challenges and strategies toward long term stability of lead free tin based perovskite solar cells

    Get PDF
    Due to their outstanding optoelectronic properties, lead based halide perovskite materials have been applied as efficient photoactive materials in solution processed solar cells. Current record efficiencies offer the promise to surpass those of silicon solar cells. However, uncertainty about the potential toxicity of lead based halide perovskite materials and their facile dissolution in water requires a search for new alternative perovskite like materials. Thanks to the foresight of scientists and their experience in lead based halide perovskite preparation, remarkable results have been obtained in a short period of time using lead free perovskite compositions. However, the lower solar to energy conversion efficiency and long term stability issues are serious drawbacks that hinder the potential progression of these materials. Here, we review and analyse strategies in the literature and the most promising solutions to identify the factors that limit the power conversion efficiency and long term stability of lead free tin based perovskite solar cells. In the light of the current state of the art, we offer perspectives for further developing these promising material

    Increased urinary markers of kidney damage in the institutionalized frail elderly due to recurrent urinary tract infections.

    Get PDF
    Objective: To characterize the impact on kidney injury of recurrent urinary tract infections (RUTI) in the frail elderly. Methods: Prospective observational study in 200 frail elderly subjects for 1 year. Groups: GA (n = 100): subjects without RUTI, GB (n = 100): subjects with RUTI. Variables: age, concomitant diseases, glomerular filtration rate (GFR), urine neutrophil gelatinase-associated lipocalin (NGAL) at the beginning (NGAL-1) and end (NGAL-2) of the study, urine N-acetyl glucosaminidase (NAG) at the beginning (NAG-1) and the end (NAG-2) of the study, urine transforming growth factor-beta 1 (TGFbeta-1). Descriptive statistics, Mann-Whitney test, Chi-squared test, Fisher's exact test, and multivariate analysis were used. Results: Mean age was 84.33 (65-99) years old, with no difference between GA and GB. Mean NGAL-1 was 1.29 ng/ml (0.04-8). There was lower in GA than in GB. Mean NGAL-2 was 1.41 ng/ml (0.02-9.22). NGAL-2 was lower in GA than in GB. Mean NAG-1 was 0.38 UU.II/ml (0.01-2.63. NAG-1 in GA was lower than in GB. Mean NAG-2 was 0.44 UU.II/ml (0-3.41). NAG-2 was lower in GA compared with GB. Mean TGFbeta-1 was 23.43 pg/ml (0.02-103.76). TGFbeta-1 was lower in GA than GB. There were no differences in the presence of secondary diagnoses between GA and GB. NAG-2 and NGAL-1 were the most determining factors of renal function; in GA it was NGAL-2, followed by NAG-1; in GB it was NGAL-1, followed by NAG-2. Conclusion: Frail elderly with RUTI have higher urinary levels of renal injury markers, specifically NGAL, NAG, and TGFbeta-1, chronically in periods between urinary tract infection (UTI). Urinary markers of renal injury, specifically NGAL, NAG, and TGFbeta-1, identify early deterioration of renal function, compared with serum creatinine, or albuminuria, in frail elderly with recurrent urinary infections

    Correlation of RECIST, Computed Tomography Morphological Response, and Pathological Regression in Hepatic Metastasis Secondary to Colorectal Cancer: The AVAMET Study.

    Get PDF
    Background: The prospective phase IV AVAMET study was undertaken to correlate response evaluation criteria in solid tumors (RECIST)-defined response rates with computed tomography-based morphological criteria (CTMC) and pathological response after liver resection of colorectal cancer metastases. Methods: Eligible patients were aged >/=18 years, with Eastern Cooperative Oncology Group (ECOG) performance status 0/1 and histologically-confirmed colon or rectal adenocarcinoma with measurable liver metastases. Preoperative treatment was bevacizumab (7.5 mg on day 1) + XELOX (oxaliplatin 130 mg/m(2), capecitabine 1000 mg/m(2) bid on days 1-14 q3w). After three cycles, response was evaluated by a multidisciplinary team. Patients who were progression-free and metastasectomy candidates received one cycle of XELOX before undergoing surgery 3-5 weeks later, followed by four cycles of bevacizumab + XELOX. Results: A total of 83 patients entered the study; 68 were eligible for RECIST, 67 for CTMC, and 51 for pathological response evaluation. Of these patients, 49% had a complete or partial RECIST response, 91% had an optimal or incomplete CTMC response, and 81% had a complete or major pathological response. CTMC response predicted 37 of 41 pathological responses versus 23 of 41 responses predicted using RECIST (p = 0.008). Kappa coefficients indicated a lack of correlation between the results of RECIST and morphological responses and between morphological and pathological response rates. Conclusion: CTMC may represent a better marker of pathological response to bevacizumab + XELOX than RECIST in patients with potentially-resectable CRC liver metastases

    Genome-wide association analysis of dementia and its clinical endophenotypes reveal novel loci associated with Alzheimer's disease and three causality networks: The GR@ACE project

    Get PDF
    INTRODUCTION: Large variability among Alzheimer's disease (AD) cases might impact genetic discoveries and complicate dissection of underlying biological pathways. METHODS: Genome Research at Fundacio ACE (GR@ACE) is a genome-wide study of dementia and its clinical endophenotypes, defined based on AD's clinical certainty and vascular burden. We assessed the impact of known AD loci across endophenotypes to generate loci categories. We incorporated gene coexpression data and conducted pathway analysis per category. Finally, to evaluate the effect of heterogeneity in genetic studies, GR@ACE series were meta-analyzed with additional genome-wide association study data sets. RESULTS: We classified known AD loci into three categories, which might reflect the disease clinical heterogeneity. Vascular processes were only detected as a causal mechanism in probable AD. The meta-analysis strategy revealed the ANKRD31-rs4704171 and NDUFAF6-rs10098778 and confirmed SCIMP-rs7225151 and CD33-rs3865444. DISCUSSION: The regulation of vasculature is a prominent causal component of probable AD. GR@ACE meta-analysis revealed novel AD genetic signals, strongly driven by the presence of clinical heterogeneity in the AD series
    corecore