519 research outputs found

    Reología de mezclas de cemento con filler dolomítico

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    This experimental program has studied the behavior of fresh paste made up from cements mixed with dolomite filler. Through prior experiments the starting point is obtained for the designs 22 and 23 factorials. With these designs the governing equations are established that influence the specific surface of the filler, the filler percentage and the ratio water/(cement + filler), used as objective functions: test probe penetration, flow on table and shear stress in viscometer. Also the type of rheological conduct is determined and the influence over initial and final setting is observed.Este programa experimental estudia el comportamiento de las pastas frescas fabricadas a partir de cementos mezclados con filler dolomítico. En los experimentos previos se obtiene el punto central para los diseños 22 y 23 factoriales. Con estos diseños se establecen las ecuaciones que rigen la influencia de la superficie específica del filler, el porcentaje de filler y la relación agua/(cemento + filler), utilizando como funciones objetivos la penetración de sonda, la mesa de sacudidas y la tensión de corte en el viscosímetro. También se determina el tipo de conducta reológica y la influencia sobre el principio y fin de fraguado

    Identifying clinical clusters with distinct trajectories in first-episode psychosis through an unsupervised machine learning technique

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    The extreme variability in symptom presentation reveals that individuals diagnosed with a first-episode psychosis (FEP) may encompass different sub-populations with potentially different illness courses and, hence, different treatment needs. Previous studies have shown that sociodemographic and family environment factors are associated with more unfavorable symptom trajectories. The aim of this study was to examine the dimensional structure of symptoms and to identify individuals’ trajectories at early stage of illness and potential risk factors associated with poor outcomes at follow-up in non-affective FEP. One hundred and forty-four non-affective FEP patients were assessed at baseline and at 2-year follow-up. A Principal component analysis has been conducted to identify dimensions, then an unsupervised machine learning technique (fuzzy clustering) was performed to identify clinical subgroups of patients. Six symptom factors were extracted (positive, negative, depressive, anxiety, disorganization and somatic/cognitive). Three distinct clinical clusters were determined at baseline: mild; negative and moderate; and positive and severe symptoms, and five at follow-up: minimal; mild; moderate; negative and depressive; and severe symptoms. Receiving a low-dose antipsychotic, having a more severe depressive symptomatology and a positive family history for psychiatric disorders were risk factors for poor recovery, whilst having a high cognitive reserve and better premorbid adjustment may confer a better prognosis. The current study provided a better understanding of the heterogeneous profile of FEP. Early identification of patients who could likely present poor outcomes may be an initial step for the development of targeted interventions to improve illness trajectories and preserve psychosocial functioning

    Transcriptional dynamics of pluripotent stem cell-derived endothelial cell differentiation revealed by single-cell RNA sequencing

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    Aims Pluripotent stem cell-derived endothelial cell products possess therapeutic potential in ischaemic vascular disease. However, the factors that drive endothelial differentiation from pluripotency and cellular specification are largely unknown. The aims of this study were to use single-cell RNA sequencing (scRNA-seq) to map the transcriptional landscape and cellular dynamics of directed differentiation of human embryonic stem cell-derived endothelial cells (hESC-EC) and to compare these cells to mature endothelial cells from diverse vascular beds. Methods and results A highly efficient directed 8-day differentiation protocol was used to generate a hESC-derived endothelial cell product (hESC-ECP), in which 66% of cells co-expressed CD31 and CD144. We observed largely homogeneous hESC and mesodermal populations at Days 0 and 4, respectively, followed by a rapid emergence of distinct endothelial and mesenchymal populations. Pseudotime trajectory identified transcriptional signatures of endothelial commitment and maturation during the differentiation process. Concordance in transcriptional signatures was verified by scRNA-seq analysis using both a second hESC line RC11, and an alternative hESC-EC differentiation protocol. In total, 105 727 cells were subjected to scRNA-seq analysis. Global transcriptional comparison revealed a transcriptional architecture of hESC-EC that differs from freshly isolated and cultured human endothelial cells and from organ-specific endothelial cells. Conclusion A transcriptional bifurcation into endothelial and mesenchymal lineages was identified, as well as novel transcriptional signatures underpinning commitment and maturation. The transcriptional architecture of hESC-ECP was distinct from mature and foetal human EC.This work was supported by the Medical Research Council [MRC Precision Medicine Doctoral Training Programme to I.R.M. and both the MRC Discovery Award and Programme grant (MC_PC_15075) and MRC Programme: Computational and Disease Genomics (MC_UU_00007/15) to C.P.P.], the Wellcome Trust [Wellcome Trust Senior Research Fellowship in Clinical Science (ref. 103749) to N.C.H.], the European Research Council [Advanced Grant VASCMIR (RE7644) to A.H.B.], and the British Heart Foundation [BHF CVR grant (RM/17/3/ 33381) and BHF Chair of Translational Cardiovascular Sciences to A.H.B.]

    La representación social de la delincuencia

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    El presente trabajo es fruto de la labor investigadora que está llevando a cabo el Instituto Vasco de Criminología de San Sebastián (IVAC) dentro de la línea de estudio sobre las teorías de las representaciones sociales sobre la delincuencia. Se trata de una investigación básicamente descriptiva, aunque pretendidamente también explorativa. Tiene como objetivo el conocimiento de las representaciones sociales que los jóvenes tienen sobre el delito, los factores etiológicos, los delincuentes y las instituciones creadas para resolver los conflictos-delitos. De este planteamiento se deriva su hipótesis fundamental, que mantiene que no existe una única imagen social, sino varias, determinadas por diferentes situaciones vitales

    Relationship between cognition and age at onset of first-episode psychosis: comparative study between adolescents, young adults, and adults

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    Psychotic disorders typically manifest from late adolescence to early adulthood, and an earlier onset might be associated with greater symptom severity and a worse long-term prognosis. This study aimed to compare the cognitive characteristics of patients with first-episode psychosis (FEP) by their age at onset. We included 298 patients diagnosed with FEP and classified them as having an early onset (EOS), youth onset (YOS), or adult onset (AOS) based on age limits of = 25 years (N = 116), respectively. Socio-demographic and clinical variables included age at baseline, gender, socio-economic status, antipsychotic medication, DSM-IV diagnoses assessed by clinical semi-structured interview, psychotic symptom severity, and age at onset. Neuropsychological assessment included six cognitive domains: premorbid intelligence, working memory, processing speed, verbal memory, sustained attention, and executive functioning. The EOS group had lower scores than the YOS or AOS groups in global cognition, executive functioning, and sustained attention. Although the scores in the YOS group were intermediate to those in the EOS and AOS groups for most cognitive factors, no statistically significant differences were detected between the YOS and AOS groups. Age at onset results in specific patterns of cognitive interference. Of note, impairment appears to be greater with EOS samples than with either YOS or AOS samples. A longitudinal study with a larger sample size is needed to confirm our findings

    Cognitive clusters in first-episode psychosis

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    Impairments in a broad range of cognitive domains have been consistently reported in some individuals with first-episode psychosis (FEP). Cognitive deficits can be observed during the prodromal stage. However, the course of cognitive deficits is still unclear. The aim of this study was to identify cognitive subgroups over time and to compare their sociodemographic, clinical and functional profiles. A total of 114 patients with Schizophrenia Spectrum Disorders were included in the present study. We assessed subjects through psychiatric scales and eight neuropsychological tests at baseline and at two-year follow-up visit. We performed the Partition Around Medoids algorithm with all cognitive variables. Furthermore, we performed a logistic regression to identify the predictors related to the different cognitive clusters at follow-up. Two distinct subgroups were found: the first cluster characterized by cognitive impairment and a second cluster had relatively intact cognition in comparison with norms. Up to 54.7% of patients with cognitive deficits at baseline tended to improve during the first two years of treatment. Patients with intact cognition at follow-up had a higher socioeconomic status, later age of onset, lower negative symptoms and a higher cognitive reserve (CR) at baseline. CR and age of onset were the baseline variables that predicted cognitive impairment. This research allows us to obtain a better understanding of the heterogeneous profile of psychotic disorders. Identifying the characteristics of patients who will present a cognitive impairment could improve early detection and intervention. These results suggest that enhancing CR could contribute to improving the course of the illness. © 2021 Elsevier B.V

    The role of premorbid iq and age of onset as useful predictors of clinical, functional outcomes, and recovery of individuals with a first episode of psychosis

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    Background: premorbid IQ (pIQ) and age of onset are predictors of clinical severity and long-term functioning after a first episode of psychosis. However, the additive influence of these variables on clinical, functional, and recovery rates outcomes is largely unknown. Methods: we characterized 255 individuals who have experienced a first episode of psychosis in four a priori defined subgroups based on pIQ (low pIQ < 85; average pIQ = 85) and age of onset (early onset < 18 years; adult onset = 18 years). We conducted clinical and functional assessments at baseline and at two-year follow-up. We calculated symptom remission and recovery rates using the Positive and Negative Symptoms of Schizophrenia Schedule (PANSS) and the Global Assessment Functioning (GAF or Children-GAF). We examined clinical and functional changes with pair-wise comparisons and two-way mixed ANOVA. We built hierarchical lineal and logistic regression models to estimate the predictive value of the independent variables over functioning or recovery rates. Results: early-onset patients had more severe positive symptoms and poorer functioning than adult-onset pa-tients. At two-year follow-up, only early-onset with low pIQ and adult-onset with average pIQ subgroups differed consistently, with the former having more negative symptoms (d = 0.59), poorer functioning (d = 0.82), lower remission (61% vs. 81.1%), and clinical recovery (34.1% vs. 62.2%). Con-clusions: early-onset individuals with low pIQ may present persistent negative symptoms, lower functioning, and less recovery likelihood at two-year follow-up. Intensive cognitive and functional programs for these individuals merit testing to improve long-term recovery rates in this subgroup. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
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