158 research outputs found
A generalized linear model for cardiovascular complications prediction in PD patients
[Abstract] This study was conducted using machine learning models to identify patient non-invasive information for cardiovascular complications prediction in peritoneal dialysis patients. Nowadays is well known that cardiovascular diseases are the key to mortality in patients undergoing peritoneal dialysis as the risk of cardiovascular disease increases with the progression of renal failure. Primary aim is to establish variables most associated with cardiovascular complications. To achieve this goal four different machine learning techniques were used. We found that the best classification algorithm was a Generalized Linear Model, which achieved AUC values above 96% using a small subset of the original variables following a feature selection approach. Our approach allows us to increase the interpretability of the combinations of traditional factors, advanced chronic kidney disease factors and peritoneal dialysis factors all related with cardiovascular risk profile. The final model is based primarily in the traditional factors.Instituto de Salud Carlos III; PI17/01826Xuinta de Galicia; ED431G/01Xunta de Galicia; ED431D 2017/1Xunta de Galicia; ED431D 2017/2Ministerio de Economía y Competitividad; UNLC08-1E-002Ministerio de Economía y Competitividad; UNLC13-13-350
Computational and statistical methodologies for ORFeome primary structure analysis
Codon usage and context are biased in open reading frames (ORFs) of most genomes. Codon usage is largely influenced by biased genome G+C pressure, in particular in prokaryotes, but the general rules that govern the evolution of codon context remain largely elusive. In order to shed new light into this question we have developed computational, statistical and graphical tools for analysis of codon context on an ORFeome wide scale. In here, we describe these methodologies in detail and show how they can be used for analysis of ORFs of any genome sequenced.publishe
A distributed system for microelectronic algorithms
Microelectronics tools tend to consume large amounts of memory and processor time. When circuit size outgrows the resources available on a station, its time for a scalable tool architecture. Applied to design rule checking of jlattened masks, this distributed; object-oriented architecture summons together the power of small, cheap desktop computers. The distributed system enables processing of larger circuits, assigning distinct parts of the problem to each machine. Larger circuits can be tested and testing time reduced as more computers are aggregated to the process
Application of hyperthermia for cancer treatment: Synthesis and characterization of magnetic nanoparticles and their internalization on tumor cell lines
FEDER funds through the COMPETE 2020 Program under the project number POCI-01-0145-FEDER-007688.
This work was also funded by the Scientific merit prize Santander-Totta - Lisbon New University - "Antibody engineering for breast cancer therapy" 2013.
Catarina I. P. Chaparro also acknowledges the financial support from Liga Portuguesa Contra o Cancro (LPCC)/Pfizer 2017.Truncated sialylated O-glycans, such as cell-surface carbohydrate antigen sialyl-Tn (STn) are overexpressed by several cancer types, but not by the respective normal tissues. STn expression is associated with oncogenesis and metastatic ability of cancer cells, with reduced overall survival and lack of response to chemotherapy. Advances in nanomedicine have resulted in rapid development of biocompatible superparamagnetic iron oxide nanoparticles (SPIONs) with considerable potential in cancer treatment. Therefore, in this study SPIONs coated with oleic acid (OA) or dimercaptosuccinic acid (DMSA) were developed and characterized for internalization in two breast cancer cell lines: cell line expressing the STn antigen and the corresponding control. SPIONs with an average diameter of 8 nm showed superparamagnetic behavior and high potential to be used as magnetic hyperthermia agents. OA and DMSA coating provided high stability of SPIONs in physiological conditions while not changing their main properties. NPs internalization studies showed a higher accumulation of DMSA coated NPs in the breast cancer MDA-MB-231 WT cell line. In MDA-MB-231 cell line expressing STn both coated NPs showed a similar accumulation. Therefore, STn antigen can act as a receptor capable of detecting and covalently bind to the molecules present on NPs surface and induce their cellular uptake by endocytosis.publishersversionpublishe
Effect of Tetramethylammonium Hydroxide on Nucleation, Surface Modification and Growth of Magnetic Nanoparticles
Nanoparticles of magnetite (Fe3O4) were obtained by reacting ferric chloride with sodium sulphite, through the reduction-precipitation method. The effects of adding tetramethylammonium hydroxide (TMAOH) during or after the precipitation of the iron oxide were studied in an attempt to obtain well-dispersed magnetite nanoparticles. Accordingly, the following experimental conditions were tested: (i) precipitation in absence of TMAOH (sample Mt), (ii) the same as (i) after peptizing with TMAOH (Mt1), (iii) TMAOH added to the reaction mixture during the precipitation of magnetite (Mt2). Analyses with transmission electron microscopy (TEM), X-ray diffraction, Mössbauer spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), zeta potential, and magnetization measurements up to 2.5 T revealed that magnetite was normally formed also in the medium containing TMAOH. The degree of particles agglomeration was monitored with laser diffraction and technique and inspection of TEM images. The relative contributions of Néel and Brownian relaxations on the magnetic heat dissipation were studied by investigating the ability of suspensions of these magnetite nanoparticles to release heat in aqueous and in hydrogel media. Based on ATR-FTIR and zeta potential data, it is suggested that the surfaces of the synthesized magnetite particles treated with TMAOH become coated with (CH3)4N+ cations
Through-space hopping transport in an iodine-doped perylene-based metal–organic framework
Electrically conductive metal-organic frameworks (MOFs) have emerged in the past few years as promising materials towards applications in (opto)electronics, electrocatalysis and energy storage, among others. One of the most common strategies for the design of conductive MOFs is based on the use of electroactive organic ligands and their partial oxidation/reduction to increase the number of charge carriers. Although perylene salts were reported as the first molecular conductors, they have been scarcely explored as building blocks for the construction of conductive MOFs. Herein we report the electrical conductivity enhancement of a microporous perylene-based MOF upon partial ligand oxidation by using two-probe single-crystal devices. The origin of the conductivity enhancement is rationalised by means of spectroscopic studies and quantum-chemical calculations, supporting a through-space hopping transport along the herringbone perylene packing. This study opens the way for the design of conductive MOFs based on perylene building blocks.publishe
Concurrent agreement between an anthropometric model to predict thigh volume and dual-energy X-Ray absorptiometry assessment in female volleyball players aged 14-18 years
© 2016 The Author(s).Background: A variety of performance outputs are strongly determined by lower limbs volume and composition in children and adolescents. The current study aimed to examine the validity of thigh volume (TV) estimated by anthropometry in late adolescent female volleyball players. Dual-energy X-ray absorptiometry (DXA) measures were used as the reference method. Methods: Total and regional body composition was assessed with a Lunar DPX NT/Pro/MD+/Duo/Bravo scanner in a cross-sectional sample of 42 Portuguese female volleyball players aged 14-18 years (165.2 ± 0.9 cm; 61.1 ± 1.4 kg). TV was estimated with the reference method (TV-DXA) and with the anthropometric method (TV-ANTH). Agreement between procedures was assessed with Deming regression. The analysis also considered a calibration of the anthropometric approach. Results: The equation that best predicted TV-DXA was: -0.899 + 0.876 × log10 (body mass) + 0.113 × log10 (TV-ANTH). This new model (NM) was validated using the predicted residual sum of squares (PRESS) method (R2PRESS = 0.838). Correlation between the reference method and the NM was 0.934 (95%CI: 0.880-0.964, Sy·x = 0.325 L). Conclusions: A new and accurate anthropometric method to estimate TV in adolescent female volleyball players was obtained from the equation of Jones and Pearson alongside with adjustments for body mass
Reproducibility of peak power output during a 10-s cycling maximal effort using different sampling rates
Myeloid C/EBPβ deficiency reshapes microglial gene expression and is protective in experimental autoimmune encephalomyelitis
Background CCAAT/enhancer binding protein β (C/EBPβ) is a transcription factor that regulates the expression of important pro-inflammatory genes in microglia. Mice deficient for C/EBPβ show protection against excitotoxic and ischemic CNS damage, but the involvement in this neuroprotective effect of the various C/EBPβ-expressing cell types is not solved. Since C/EBPβ-deficient microglia show attenuated neurotoxicity in culture, we hypothesized that specific C/EBPβ deficiency in microglia could be neuroprotective in vivo. In this study, we have tested this hypothesis by generating mice with myeloid C/EBPβ deficiency. Methods Mice with myeloid C/EBPβ deficiency were generated by crossing LysMCre and C/EBPβfl/fl mice. Primary microglial cultures from C/EBPβfl/fl and LysMCre-C/EBPβfl/fl mice were treated with lipopolysaccharide ± interferon γ (IFNγ) for 6 h, and gene expression was analyzed by RNA sequencing. Gene expression and C/EBPβ deletion were analyzed in vivo in microglia isolated from the brains of C/EBPβfl/fl and LysMCre-C/EBPβfl/fl mice treated systemically with lipolysaccharide or vehicle. Mice of LysMCre-C/EBPβfl/fl or control genotypes were subjected to experimental autoimmune encephalitis and analyzed for clinical signs for 52 days. One- or two-way ANOVA or Kruskal-Wallis with their appropriate post hoc tests were used. Results LysMCre-C/EBPβfl/fl mice showed an efficiency of C/EBPβ deletion in microglia of 100 and 90% in vitro and in vivo, respectively. These mice were devoid of female infertility, perinatal mortality and reduced lifespan that are associated to full C/EBPβ deficiency. Transcriptomic analysis of C/EBPβ-deficient primary microglia revealed C/EBPβ-dependent expression of 1068 genes, significantly enriched in inflammatory and innate immune responses GO terms. In vivo, microglial expression of the pro-inflammatory genes Cybb, Ptges, Il23a, Tnf and Csf3 induced by systemic lipopolysaccharide injection was also blunted by C/EBPβ deletion. CNS expression of C/EBPβ was upregulated in experimental autoimmune encephalitis and in multiple sclerosis samples. Finally, LysMCre-C/EBPβfl/fl mice showed robust attenuation of clinical signs in experimental autoimmune encephalitis. Conclusion This study provides new data that support a central role for C/EBPβ in the biology of activated microglia, and it offers proof of concept for the therapeutic potential of microglial C/EBPβ inhibition in multiple sclerosis
Aplicação de patterns no desenvolvimento de um sistema CAD para microeletrônica
Apresenta a aplicação de técnica de orientação a objetos para resolver problemas de integração em ferramentas de CAD para microeletrônica. A abordagem enfatiza o uso de patterns e componentização para obter homogeneidade e o reuso de software. Os componentes são responsáveis por realizar tarefas básicas como a interpretação de linguagens e edição gráfica. A divisão de arquitetura em camadas garante a modularidade e provê o acoplamento de ferramentas funcionais. A arquitetura também suporta a distribuição de objetos, aumentando o potencial de processamento em redes de computadores
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