2,310 research outputs found
Scaling the drop size in coflow experiments
We perform extensive experiments with coflowing liquids in microfluidic devices and provide a closed expression for the drop size as a function of measurable parameters in the jetting regime that accounts for the
experimental observations; this expression works irrespective of how the jets are
produced, providing a powerful design tool for this type of experiment
Controllable production of Janus ligaments by AC fields in a flow-focusing junction
We report the production of bicomponent Janus filaments of miscible aqueous fluids in a micro- fluidic electro-flow focusing device under the action of an AC electric field. The production of liquid filaments can lead to the generation of microfibers by adding a subsequent process of polymerization. Janus microfi- bers are of paramount importance in biomedical appli- cations such as tissue production on crimped scaffolds. We show that the filament length is a function of the frequency signal, voltage amplitude and of the visco- sity and conductivity of the dispersed phase. In par- ticular, Janus filaments with diameters ∼ 10μm and longer than 1 mm are produced by AC voltages with frequencies below 150 kHz and a viscosity of the dis- persed phase ∼ 10 cP
Lipid Composition and Associated Gene Expression Patterns during Pollen Germination and Pollen Tube Growth in Olive (Olea europaea L.)
Pollen lipids are essential for sexual reproduction but our current knowledge regarding lipid dynamics in growing pollen tubes is still very scarce. Here, we report unique lipid composition and associated gene expression patterns during olive pollen germination. Up to 376 genes involved in the biosynthesis of all lipid classes, except suberin, cutin and lipopolysaccharides, are expressed in the olive pollen. The fatty acid profile of the olive pollen is markedly different compared with other plant organs. Triacylglycerol, containing mostly C12-C16 saturated fatty acids, constitutes the bulk of olive pollen lipids. These compounds are partially mobilized, and the released fatty acids enter the β-oxidation pathway to yield acetyl-CoA, which is converted into sugars through the glyoxylate cycle in the course of pollen germination. Our data suggest that fatty acids are synthesized de novo and incorporated into glycerolipids by the “eukaryotic pathway” in elongating pollen tubes. Phosphatidic acid is synthesized de novo in the endomembrane system during pollen germination and seems to have a central role in the pollen tube lipid metabolism. The coordinated action of fatty acid desaturases FAD2-3 and FAD3B might explain the increase of linoleic and alpha-linolenic acids observed in the germinating pollen. A continuous synthesis of triacylglycerol by the action of DGAT1 enzyme, but not PDAT, seems also plausible. All these data allow for a better understanding of the lipid metabolism during the olive reproduction process, which can impact in the future in the increase of olive fruit yield and, therefore, olive oil production
¿Los culpables son los electrones?: una propuesta experimental a microescala de las reacciones redox
En el presente trabajo se describe una propuesta experimental en microescala que busca que los estudiantes expliquen los conceptos de reacciones de óxido reducción (redox), su asociación al potencial estándar, espontaneidad de una reacción y termoquímica, a partir de la reacción entre el Cu(SO₄)₂ 5H₂O y aluminio en presencia de NaCl. Esta experiencia práctica, diseñada como una actividad experimental a realizar en casa, busca atender los objetivos de aprendizaje de un curso de química inorgánica, en condiciones de confinamiento por la pandemia de COVID-19, aprovechando las bondades de la química en microescala. Es un experimento que se puede realizar de manera segura en casa (siguiendo las medidas de seguridad del experimento), con reactivos asequibles empleando pequeñas cantidades.This paper presents a microscale experimental proposal that seeks for students to explain the concepts of redox reactions (redox), associated with standard potential, spontaneous processes, and thermochemistry; from the reaction between Cu(SO₄)₂ 5H₂O and aluminum in the presence of NaCl. This practical experience, which arises from the experimental work carried out at home during the pandemic caused by COVID-19, takes advantage of the benefits of the microscale in chemistry, it is an experiment that can be carried out safely at home, with affordable reagents that are used in very small quantities
Síntesis y caracterización de LaCoO₃±δ por el método de Pechini para su evaluación como cátodo en una CCOS
Las celdas de combustible están compuestas por dos electrodos y un electrolito sólido, que convierten la energía química a energía eléctrica, reduciendo las emisiones contaminantes y aumentando su eficiencia. En este trabajo se sintetizó LaCoO₃±δ mediante el método Pechini; el cual permite tener un buen control en la microestructura obtenida para su aplicación como cátodo. Posterior a la síntesis, el material fue caracterizado por ATG/ADB con lo que se establecieron las etapas de formación del compuesto y la temperatura de estabilización y su pérdida de masa. Con el estudio de DRX en polvos se identificó la fase estudiada, así como la completez de la reacción para posteriormente realizar el refinamiento LeBail y obtener los parámetros de celda. El análisis morfológico se realizó mediante MFA y MEB. Las características anteriores permitirán su uso como cátodo en una celda de combustible de óxidos sólidos.The fuel cells are conformed by two electrodes and a solid electrolyte, in this device the chemical energy is transformed into electric energy, by means of this method it is possible the abatement of environmental pollution and the efficiency is enhanced. In this study, the synthesis of LaCoO₃±δ was carried out by the Pechini method; this method allows having a good control in the microstructure for cathode application. The material obtained it was characterized by TGA/DSC this analysis we can obtained the stages of formation of the compound, the stabilization temperature and its loss of mass. With the powder XRD, we identified the crystallographic phase studied, as well as the reaction complete, and then the LeBail refinement was performed in order to obtain the lattice parameters. We made the morphology analysis with AFM and SEM. These characteristics and properties allow its use as a cathode in solid oxides fuel cell
Adipose Tissue in Health and Disease
Obesity, being an epidemy these days, is the trigger of metabolic disturbances such as cardiovascular disease, type 2 diabetes, and insulin resistance. Defined as an increase in fat storage, adipose tissue has been put under the spotlight as the culprit of these conditions, as it is composed not only by adipocytes but of any immune system cell and a singular extracellular matrix. Its behavior under acute and chronic hypercaloric states is quite different; persistent hypertrophy in the latter creates hypoxia, resulting in the release of reactive oxygen species and proinflammatory cytokines that impact on the immune response type of the resident leucocytes, mainly macrophages. Hypertrophy over hyperplasia, adipose tissue macrophages-M1 phenotype polarization, and the adipokines/myokines profile are thought to be regulated by foreign microRNAs, delivered from surrounding or distant cells by exosomes through the bloodstream. In this chapter, we focus on adipose tissue immunometabolism and how obesity causes the chronic inflammatory state, and, subsequently, this stablishes a pathologic adiposity, characterized by dyslipidemia and insulin resistance (IR)
Procedimiento de preparación de partículas de tamaño micro y nanométrico con productos lábiles y partículas obtenidas
Procedimiento de preparación de partículas de tamaño
micro y nanométrico con productos lábiles y partículas obtenidas.
La presente invención esta relacionada con la obtención
de partículas poliméricas de tamaño micro y nanométrico
de una forma controlable y reproducible. Las partículas
tienen forma esférica y una distribución de tamaño muy
estrecha y homogénea. Mas particularmente, la presente invención describe el use y utilización de un método
suave de formación de partículas y su aplicación a la encapsulación de compuestos frágiles de interés biológico,
incluyendo desde péptidos y proteínas hasta células y microorganismos.Españ
Prognostic Score and Benefit from Abiraterone in First-line Metastatic, Castration-resistant Prostate Cancer.
Most available prognostic nomograms in metastatic castration-resistant prostate cancer (mCRPC) are derived from datasets not representative of the current treatment landscape. A prognostic nomogram for first-line mCRPC treatment was developed from patients treated in the PREVAIL study.
To validate the Armstrong model in the COU-AA-302 trial.
A post hoc analysis of mCRPC patients treated in the COU-AA-302 trial was carried out (NCT00887198).
The Armstrong prognostic model was applied to patients treated in COU-AA-302. A continuous risk score was derived from coefficients from the original model. Time-dependent area under the curve (tAUC) was used to evaluate the overall predictive ability of the model. Patients were categorized according to the number of risk factors present into those at a low (three or fewer risk factors), intermediate (four to six risk factors), and high (seven to ten risk factors) risk. The association with survival was assessed with Cox regression models. Interaction tests were used to assess the impact of treatment arm in each of the prognostic groups.
A total of 1088 patients were analyzed. The risk score was associated with overall survival (OS; tAUC 0.733). Most patients were at a low (49%) or intermediate (41%) risk. Risk category was significantly associated with OS (hazard ratio [HR]: 2.3; 95% confidence interval [CI]: 1.9-2.4; p < 0.001), radiographic progression-free survival (rPFS; HR: 1.7; 95% CI: 1.5-1.8; p < 0.001), and prostate-specific antigen progression-free survival (HR: 1.7; 95% CI: 1.5-1.9; p < 0.001). A significant interaction between risk group and OS (p = 0.007) and rPFS (p = 0.009) was observed. Survival was superior in low-risk patients (HR: 0.73; 95% CI: 0.59-0.89; p = 0.009), but similar in intermediate-risk (HR: 0.97; 95% CI: 0.79-1.21; p = 0.9) and high-risk (HR: 1.35; 95% CI: 0.80-2.28; p = 0.5) patients. Two-year OS rates in abiraterone versus placebo were 82% versus 74% in low-risk, 55% versus 52% in intermediate-risk, and 28% versus 31% in high-risk patients.
We validate the prognostic value of the Armstrong risk model in patients treated with first-line androgen receptor signaling inhibitors. Abiraterone provided a greater benefit in low-risk patients with less aggressive disease. Further research is needed to establish the role of Armstrong risk groups for treatment selection in mCRPC patients.
In this report, we validated the Armstrong nomogram in the COU-AA-302 trial population. We found a similar prognostic performance to that of the original model. Good-risk patients received the greatest benefit from abiraterone.Authors acknowledge funding support from Ministerio de Economía y Competitividad de España -Instituto de Salud Carlos III: grants CM17-00221 (Rebeca Lozano), CM19/00234 (Casilda Llacer), JR17/00007 (Nuria Romero-Laorden), and JR18/00011 (Elena Castro); Ministerio de Ciencia e Innovación: RYC-2015-18625 (David Olmos); and Prostate Cancer Foundation: Young Investi-gator Award (2014 David Olmos, 2017 Elena Castro).S
The epigenetic factor BORIS (CTCFL) controls the androgen receptor regulatory network in ovarian cancer
Robust Field-level Likelihood-free Inference with Galaxies
© 2023. The Author(s). Published by the American Astronomical Society. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/We train graph neural networks to perform field-level likelihood-free inference using galaxy catalogs from state-of-the-art hydrodynamic simulations of the CAMELS project. Our models are rotational, translational, and permutation invariant and do not impose any cut on scale. From galaxy catalogs that only contain 3D positions and radial velocities of ∼1000 galaxies in tiny (25h−1Mpc)3 volumes our models can infer the value of Ωm with approximately 12% precision. More importantly, by testing the models on galaxy catalogs from thousands of hydrodynamic simulations, each having a different efficiency of supernova and active galactic nucleus feedback, run with five different codes and subgrid models—IllustrisTNG, SIMBA, Astrid, Magneticum, SWIFT-EAGLE—we find that our models are robust to changes in astrophysics, subgrid physics, and subhalo/galaxy finder. Furthermore, we test our models on 1024 simulations that cover a vast region in parameter space—variations in five cosmological and 23 astrophysical parameters—finding that the model extrapolates really well. Our results indicate that the key to building a robust model is the use of both galaxy positions and velocities, suggesting that the network has likely learned an underlying physical relation that does not depend on galaxy formation and is valid on scales larger than ∼10 h −1 kpc.Peer reviewe
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