254 research outputs found
Experimental investigation of the lift-offheight and soot formation of a spray flame for different co-flow conditions and fuels
[EN] Since the combustion process in spray flames is a highly complex multi-phase phenomenon, which involves several simultaneous processes such as atomization, vaporization, and chemical kinetics, it is still not fully understood. In the present work, an experimental investigation has been performed for three different hydrocarbon fuels (n-Heptane, n-Decane, n-Dodecane), in order to understand the effect of varying co-flow conditions, fuel mass flow rate, and fuel type on both the flame lift-off height and soot formation. The fuels were injected through a hollow-cone spray injector, with a nominal spray cone angle of 80 degrees and orifice diameter of 120 mu m in an annular non-swirled preheated air co-flow. The flame lift-off height was determined by recording the OH * chemiluminescence, whereas soot formation has been determined through the color diffused back-illumination extinction technique. From the results, it has been observed for a certain fuel that the flame lift-off height is mainly controlled by the co-flow velocity and air co-flow temperature. The results also show that the fuel that yields largest droplet size and that possesses the lowest volatility exhibits the highest flame lift-off height. Furthermore, the results evidence a strong influence of the co-flow velocity on the soot formation. With an increase in co-flow velocity, the flame lift-off height is increased and so the amount of air entrainment, leading to a less rich reaction zone just downstream of the lift-off height, which in turn results in less soot formation. Finally, the comparison among different fuels shows that their differences in soot formation are likely related to fuel sooting tendency. This property, in turn, depends on the fuel molecular structure playing an important role on its determination.This research was funded bythe Spanish Ministerio de Ciencias, Investigacion y Universidades through project RTI2018-099706-BI00. Part of the experimental hardware was purchased through funds obtained from Spanish Ministerio de Ciencias, Investigacion y Universidades and FEDER through project EQC2019-005818-P. The author Santiago Cardona Vargas would like to thank Universitat Politecnica de Valencia for his Predoctoral contract (FPI-2016-S1), which is included within the framework of Programa de Apoyo para la Investigacion y Desarrollo (PAID-01-2016). The authors are thankful to Jose Enrique Del Rey and Omar Huerta for helping in the technical issues, also to Carlos Gil Martinez for helping during the experimental campaign.Gimeno, J.; Marti-Aldaravi, P.; Carreres, M.; Cardona-Vargas, S. (2021). Experimental investigation of the lift-offheight and soot formation of a spray flame for different co-flow conditions and fuels. Combustion and Flame. 233:1-19. https://doi.org/10.1016/j.combustflame.2021.111589S11923
The Structural Biology of Galectin-Ligand Recognition: Current Advances in Modeling Tools, Protein Engineering, and Inhibitor Design
Galectins (formerly known as “S-type lectins”) are a subfamily of soluble proteins that typically bind β-galactoside carbohydrates with high specificity. They are present in many forms of life, from nematodes and fungi to animals, where they perform a wide range of functions. Particularly in humans, different types of galectins have been described differing not only in their tissue expression but also in their cellular location, oligomerization, fold architecture and carbohydrate-binding affinity. This distinct yet sometimes overlapping distributions and physicochemical attributes make them responsible for a wide variety of both intra- and extracellular functions, including tremendous importance in immunity and disease. In this review, we aim to provide a general description of galectins most important structural features, with a special focus on the molecular determinants of their carbohydrate-recognition ability. For that purpose, we structurally compare the human galectins, in light of recent mutagenesis studies and novel X-ray structures. We also offer a detailed description on how to use the solvent structure surrounding the protein as a tool to get better predictions of galectin-carbohydrate complexes, with a potential application to the rational design of glycomimetic inhibitory compounds. Finally, using Gal-1 and Gal-3 as paramount examples, we review a series of recent advances in the development of engineered galectins and galectin inhibitors, aiming to dissect the structure-activity relationship through the description of their interaction at the molecular level.Fil: Modenutti, Carlos Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Blanco Capurro, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Di Lella, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Marti, Marcelo Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentin
ONCOS-102 plus pemetrexed and platinum chemotherapy in malignant pleural mesothelioma: a randomized phase 2 study investigating clinical outcomes and the tumor microenvironment
T-lymphocytes; Oncolytic viruses; Tumor microenvironmentLinfocitos T; Virus oncolíticos; Microambiente tumoralLimfòcits T; Virus oncolítics; Microambient tumoralBackground ONCOS-102, an oncolytic adenovirus expressing granulocyte-macrophage colony-stimulating factor, can alter the tumor microenvironment to an immunostimulatory state. Combining ONCOS-102 with standard-of-care chemotherapy for malignant pleural mesothelioma (MPM) may improve treatment outcomes.
Methods In this open-label, randomized study, patients with unresectable MPM received intratumoral ONCOS-102 (3×1011 virus particles on days 1, 4, 8, 36, 78, and 120) and pemetrexed plus cisplatin/carboplatin (from day 22), or pemetrexed plus cisplatin/carboplatin alone. The primary endpoint was safety. Overall survival (OS), progression-free survival, objective response rate, and tumor immunologic activation (baseline and day 36 biopsies) were also assessed.
Results In total, 31 patients (safety lead-in: n=6, randomized: n=25) were enrolled. Anemia (15.0% and 27.3%) and neutropenia (40.0% and 45.5%) were the most frequent grade ≥3 adverse events (AEs) in the ONCOS-102 (n=20) and chemotherapy-alone (n=11) cohorts. No patients discontinued ONCOS-102 due to AEs. No statistically significant difference in efficacy endpoints was observed. There was a numerical improvement in OS (30-month OS rate 34.1% vs 0; median OS 20.3 vs 13.5 months) with ONCOS-102 versus chemotherapy alone in chemotherapy-naïve patients (n=17). By day 36, ONCOS-102 was associated with increased T-cell infiltration and immune-related gene expression that was not observed in the control cohort. Substantial immune activation in the tumor microenvironment was associated with survival at month 18 in the ONCOS-102 cohort.
Conclusions ONCOS-102 plus pemetrexed and cisplatin/carboplatin was well tolerated by patients with MPM. In injected tumors, ONCOS-102 promoted a proinflammatory environment, including T-cell infiltration, which showed association with survival at month 18.This work was supported by Circio, the study sponsor (no grant number)
An enzymatic biomimetic system : enhancement of catalytic efficiency with new polymeric chiral ionic Liquids synthesised by controlled radical polymerisation
Correction to the affiliations. Mistake made by original Journal.Peer reviewe
An X-ray study of the SNR G344.7-0.1 and the central object CXOU J170357.8-414302
Aims. We report results of an X-ray study of the supernova remnant (SNR)
G344.7-0.1 and the point-like X-ray source located at the geometrical center of
the SNR radio structure. Methods. The morphology and spectral properties of the
remnant and the central X-ray point-like source were studied using data from
the XMM-Newton and Chandra satellites. Archival radio data and infrared Spitzer
observations at 8 and 24 m were used to compare and study its multi-band
properties at different wavelengths. Results. The XMM-Newton and Chandra
observations reveal that the overall X-ray emission of G344.7-0.1 is extended
and correlates very well with regions of bright radio and infrared emission.
The X-ray spectrum is dominated by prominent atomic emission lines. These
characteristics suggest that the X-ray emission originated in a thin thermal
plasma, whose radiation is represented well by a plane-parallel shock plasma
model (PSHOCK). Our study favors the scenario in which G344.7-0.1 is a 6 x 10^3
year old SNR expanding in a medium with a high density gradient and is most
likely encountering a molecular cloud on the western side. In addition, we
report the discovery of a soft point-like X-ray source located at the
geometrical center of the radio SNR structure. The object presents some
characteristics of the so-called compact central objects (CCO). However, its
neutral hydrogen absorption column (N_{H}) is inconsistent with that of the
SNR. Coincident with the position of the source, we found infrared and optical
objects with typical early-K star characteristics. The X-ray source may be a
foreground star or the CCO associated with the SNR. If this latter possibility
were confirmed, the point-like source would be the farthest CCO detected so far
and the eighth member of the new population of isolated and weakly magnetized
neutron stars.Comment: 9 pages, 8 figures, accepted for publication in Astronomy and
Astrophysics. Higher resolution figures can be seen on A&
Altered expression of the immunoregulatory ligand-receptor pair CD200-CD200R1 in the brain of Parkinson's disease patients
Neuroinflammation, in which activated microglia are involved, appears to contribute to the development of Parkinson's disease (PD). However, the role of microglial activation and the mechanisms governing this process remain uncertain. We focused on one inhibitory mechanism involved in the control of microglial activation, the microglia inhibitory receptor CD200R1, and its ligand CD200, mainly expressed by neurons. The human CD200R1 gene encodes two membrane-associated and two soluble protein isoforms and the human CD200 gene encodes full-length proteins (CD200full) but also truncated (CD200tr) proteins which act as CD200R1 antagonists. Little is known about their expression in the human brain under pathological conditions. We used human peripheral blood monocytes and monocyte-derived microglia-like cells from control subjects to characterize the expression of the CD200R1 mRNA variants, which showed stimulus-specific responses. We provide evidence of increased CD200R1 (mRNA variants and protein isoforms) and CD200 expression (CD200tr mRNA) in brain tissue of PD patients, mainly in the hippocampus, as well as increased CD200 expression (CD200full and CD200tr mRNAs) in iPSCs-derived dopaminergic neurons generated from skin fibroblasts of PD patients. Our results suggest that CD200-CD200R1 signalling is altered in PD, which may affect the microglial function and constitute a potential target in therapeutic strategies for PD.© 2022. The Author(s)
Machine Learning-Based Integration of Prognostic Magnetic Resonance Imaging Biomarkers for Myometrial Invasion Stratification in Endometrial Cancer
[EN] Background: Estimation of the depth of myometrial invasion (MI) in endometrial cancer is pivotal in the preoperatively
staging. Magnetic resonance (MR) reports suffer from human subjectivity. Multiparametric MR imaging radiomics and
parameters may improve the diagnostic accuracy.
Purpose: To discriminate between patients with MI ¿ 50% using a machine learning-based model combining texture features and descriptors from preoperatively MR images.
Study Type: Retrospective.
Population: One hundred forty-three women with endometrial cancer were included. The series was split into training
(n = 107, 46 with MI ¿ 50%) and test (n = 36, 16 with MI ¿ 50%) cohorts.
Field Strength/Sequences: Fast spin echo T2-weighted (T2W), diffusion-weighted (DW), and T1-weighted gradient echo
dynamic contrast-enhanced (DCE) sequences were obtained at 1.5 or 3 T magnets.
Assessment: Tumors were manually segmented slice-by-slice. Texture metrics were calculated from T2W and ADC map
images. Also, the apparent diffusion coefficient (ADC), wash-in slope, wash-out slope, initial area under the curve at 60 sec
and at 90 sec, initial slope, time to peak and peak amplitude maps from DCE sequences were obtained as parameters. MR
diagnostic models using single-sequence features and a combination of features and parameters from the three sequences
were built to estimate MI using Adaboost methods. The pathological depth of MI was used as gold standard.
Statistical Test: Area under the receiver operating characteristic curve (AUROC), sensitivity, specificity, accuracy, positive
predictive value, negative predictive value, precision and recall were computed to assess the Adaboost models
performance.
Results: The diagnostic model based on the features and parameters combination showed the best performance to depict
patient with MI ¿ 50% in the test cohort (accuracy = 86.1% and AUROC = 87.1%). The rest of diagnostic models showed a
worse accuracy (accuracy = 41.67%¿63.89% and AUROC = 41.43%¿63.13%).
Data Conclusion: The model combining the texture features from T2W and ADC map images with the semi-quantitative
parameters from DW and DCE series allow the preoperative estimation of myometrial invasion.
Evidence Level: 4
Technical Efficacy: Stage 3This study received funding from the Global Investigator Initiated Research Committee (GIIRC) research program by Bracco S.p.A (2015/0724). The funders had no role in study design, data collection and analysis and preparation of the manuscript.Rodriguez Ortega, A.; Alegre, A.; Lago, V.; Carot Sierra, JM.; Ten-Esteve, A.; Montoliu, G.; Domingo, S.... (2021). Machine Learning-Based Integration of Prognostic Magnetic Resonance Imaging Biomarkers for Myometrial Invasion Stratification in Endometrial Cancer. Journal of Magnetic Resonance Imaging. 54(3):987-995. https://doi.org/10.1002/jmri.27625S98799554
Draft Genome Sequence of the Polyextremophilic Halorubrum sp. Strain AJ67, Isolated from Hyperarsenic Lakes in the Argentinian Puna
Halorubrum sp. AJ67, an extreme halophilic, UV resistant archae that was isolated from Laguna Antofalla in the Argentinean Puna. The draft genome sequence suggests potent enzyme candidates that are essential to survive in multiple environmental extreme conditions, as high UV radiation, elevated salinity and the presence of critical arsenic concentration.Fil: Burguener, Germán Federico. Facultad de Ciencias Exactas y Naturales. Instituto de Cálculo. Plataforma de Bioinformática Argentina; ArgentinaFil: Maldonado, Marcos Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Planta Piloto de Procesos Industriales Microbiológicos (i); Argentina. Universidad Nacional de Jujuy. Facultad de Ciencias Agrarias; ArgentinaFil: Revale, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Biología Molecular y Celular de Rosario; Argentina. Instituto de Agrobiotecnología de Rosario; ArgentinaFil: Fernández Do Porto, Darío Augusto. Facultad de Ciencias Exactas y Naturales. Instituto de Cálculo. Plataforma de Bioinformática Argentina; ArgentinaFil: Rascovan, Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular; Argentina. Instituto de Agrobiotecnología de Rosario; ArgentinaFil: Vazquez, Martin Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular; Argentina. Facultad de Ciencias Exactas y Naturales. Instituto de Cálculo. Plataforma de Bioinformática Argentina; ArgentinaFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Planta Piloto de Procesos Industriales Microbiológicos (i); ArgentinaFil: Marti, Marcelo Adrian. Facultad de Ciencias Exactas y Naturales. Instituto de Cálculo. Plataforma de Bioinformática Argentina; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Turjanski, Adrian. Facultad de Ciencias Exactas y Naturales. Instituto de Cálculo. Plataforma de Bioinformática Argentina; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; Argentin
El CD6 de la UPC: un centre d'innovació en enginyeria òptica i fotònica que ha creat un entorn emprenedor
Peer Reviewe
10 kVp rule - an anthropomorphic pelvis phantom imaging study using a CR system : impact on image quality and effective dose using AEC and manual mode
Purpose: This study aims to investigate the influence of tube potential (kVp) variation in relation to perceptual image quality and effective dose for pelvis using automatic exposure control (AEC) and non-AEC in a Computed Radiography (CR) system.
Methods and Materials: To determine the effects of using AEC and non-AEC by applying the 10 kVp rule in two experiments using an anthropomorphic pelvis phantom. Images were acquired using 10kVp increments (60-120kVp) for both experiments. The first experiment, based on seven AEC combinations, produced 49 images. The mean mAs from each kVp increment were used as a baseline for the second experiment producing 35 images. A total of 84 images were produced and a panel of 5 experienced observers participated for the image scoring using the 2AFC visual grading software. PCXMC software was used to estimate the effective dose.
Results: A decrease in perceptual image quality as the kVp increases was observed both in non-AEC and AEC experiments, however no significant statistical differences (p>0.05) were found. Image quality scores from all observers at 10 kVp increments for all mAs values using non-AEC mode demonstrates a better score up to 90kVp. Effective dose results show a statistical significant decrease (p=0.000) on the 75th quartile from 0.3 mSv at 60 kVp to 0.1 mSv at 120kVp when applying the 10 kVp rule in non-AEC mode.
Conclusion(s): No significant reduction in perceptual image quality is observed when increasing kVp whilst a marked and significant effective dose reduction is observed
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