Search

Abstract Background In respiratory fluid dynamics research, it is typically assumed that the wall of the trachea is smooth. However, the trachea is structurally supported by a series of cartilaginous rings that create undulations on the wall surface, which introduce perturbations into the flow. Even though many studies use realistic Computer Tomography (CT) scan data to capture the complex geometry of the respiratory system, its limited spatial resolution does not resolve small features, including those introduced by the cartilaginous rings. Results Here we present an experimental comparison of two simplified trachea models with Grade II stenosis (70% blockage), one with smooth walls and second with cartilaginous rings. The use a unique refractive index-matching method provides unprecedented optical access and allowed us to perform non-intrusive velocity field measurements close to the wall (e.g., Particle Image Velocimetry (PIV)). Measurements were performed in a flow regime comparable to a resting breathing state (Reynolds number Re D = 3350). The cartilaginous rings induce velocity fluctuations in the downstream flow, enhancing the near-wall transport of momentum flux and thus reducing flow separation in the downstream flow. The maximum upstream velocity in the recirculation region is reduced by 38%, resulting in a much weaker recirculation zone— a direct consequence of the cartilaginous rings. Conclusions These results highlight the importance of the cartilaginous rings in respiratory flow studies and the mechanism to reduce flow separation in trachea stenosis.

Abstract Surface‐engineered hydrophobic nanoparticles that can stabilize small gas pockets on their surfaces (i.e., gas‐stabilizing nanoparticles, GSNs) have been recently shown to be excellent contrast and cavitation agents for ultrasound theranostics. However, previously developed GSNs are not biodegradable, which limits their clinical translation potential. Here the development of biodegradable GSNs is shown by coating hydrophobically modified mesoporous silica nanoparticles with different protein solutions. It is found that these novel GSNs retain strong cavitation activity while rapidly degrading in simulated body fluid (SBF) or in vivo in days or a few weeks, respectively. Interestingly, GSNs coated with other stabilizing layers, Pluronic F127 polymer or phospholipids, demonstrated significantly slower degradation rates with only partial degradation even after a month of incubation in SBF. Next, it is shown that these biodegradable GSNs can be used to ablate tumor xenografts at lower ultrasound intensities, thus avoiding the side effects of high‐intensity ultrasound. Finally, it is shown that only tumors treated with GSNs and ultrasound can specifically enrich for circulating tumor DNA, which will improve liquid biopsies for understanding tumor heterogeneity and treatment response. Overall, this study details a simple yet effective method for preparing biodegradable GSNs with broad potential for applications in cancer diagnosis and therapy.

Montoya Mira & Sapre et al. design a microfluidic device utilizing dielectrophoresis for the enrichment of circulating neoplastic cells that possess both epithelial and immune-like characteristics. They optimized the device using in vitro models and then applied it to clinical samples for clinically relevant mutation analyses.

Some cancer cells rely heavily on non-essential biomolecules for survival, growth, and proliferation. Enzyme based therapeutics can eliminate these biomolecules, thus specifically targeting neoplastic cells; however, enzyme therapeutics are susceptible to immune clearance, exhibit short half-lives, and require frequent administration. Encapsulation of therapeutic cargo within biocompatible and biodegradable poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs) is a strategy for controlled release. Unfortunately, PLGA NPs exhibit burst release of cargo shortly after delivery or upon introduction to aqueous environments where they decompose via hydrolysis. Here, we show the generation of hybrid silica-coated PLGA (SiLGA) NPs as viable drug delivery vehicles exhibiting sub-200 nm diameters, a metastable Zeta potential, and high loading efficiency and content. Compared to uncoated PLGA NPs, SiLGA NPs offer greater retention of enzymatic activity and slow the burst release of cargo. Thus, SiLGA encapsulation of therapeutic enzymes, such as asparaginase, could reduce frequency of administration, increase half-life, and improve efficacy for patients with a range of diseases.

Sound pleasantness or annoyance perceived in urban soundscapes is a major concern in environmental acoustics. Binaural psychoacoustic parameters are helpful to describe generic acoustic environments, as it is stated within the ISO 12913 framework. In this paper, the application of a Wireless Acoustic Sensor Network (WASN) to evaluate the spatial distribution and the evolution of urban acoustic environments is described. Two experiments are presented using an indoor and an outdoor deployment of a WASN with several nodes using an Internet of Things (IoT) environment to collect audio data and calculate meaningful parameters such as the sound pressure level, binaural loudness and binaural sharpness. A chunk of audio is recorded in each node periodically with a microphone array and the binaural rendering is conducted by exploiting the estimated directional characteristics of the incoming sound by means of DOA estimation. Each node computes the parameters in a different location and sends the values to a cloud-based broker structure that allows spatial statistical analysis through Kriging techniques. A cross-validation analysis is also performed to confirm the usefulness of the proposed system.

El presente artículo tiene como objeto plantear una propuesta teórica y metodológica abierta al debate y que sustente la reflexión para la enseñanza de la historia en el currículo nacional de El Salvador. Para ello, se identifica cómo se incorpora la enseñanza de la historia en los programas de estudio de Estudios Sociales y Cívica desde primer ciclo de educación básica hasta bachillerato. A continuación se desarrolla la importancia de trabajar la conciencia histórica mediante una propuesta teórica que comprende la interrelación de una narrativa, de las dimensiones del pensamiento histórico y el pensamiento crítico, así como de un abordaje metodológico por competencias.

Mientras que la corriente principal de la filosofía moral moderna da por supuesto que la situación típica en los juicios morales debiera ser la de certeza, la filosofía moral de Aristóteles está dominada por la idea de verosimilitud. Su concepto central, el de virtud, está doblemente penetrado por aquella idea, tanto en su aspecto psicológico como en el epistemológico: no sabemos con certeza, sino sólo con probabilidad, en qué consiste por ejemplo la acción generosa en general ni tampoco en el caso concreto. Sin embargo, la verosimilitud es una base suficiente para la práctica.

Tras una introducción bibliográfica de la lectura de aquella tesis, que hace el editor del presente volumen, el Prof. Montoya ofrece una valoración del libro que la recoge, desde el punto de vista del valor de la misma como investigación y como aportación a la comprensión de la obra de Aristóteles.

En la actualidad somos afortunados de vivir en sociedades donde las libertades de pensamiento y de expresión se dan por supuestas y son amparadas por la constitución y por la leyes; e incluso fuera del marco legal, por determinadas instituciones y por la opinión pública. En este sentido, el objetivo del presente artículo es tratar críticamente los dos conceptos fundamentales en la obra On liberty de J .S. Mill, a saber, "tolerancia" y "libertad". Especialmente se aborda su justificación a partir del segundo capítulo de dicha obra, titulado "of the liberty of thought and discussion". Nowadays we are fortunate to live in societies where freedom of thought and expression are taken for granted and protected by constitutions and laws, and even outside the legal framework, by certain institutions and public opinion. In this vein, the present paper aims to critically address thetwo essential concepts in on liberty by J.S. Mill, namely, "tolerance" and "liberty". In particular, the second chapter of this work, "of the liberty of thought and discussion" provides the starting point for discussion of its justification.

This article tries to throw some light on the relations between thought and language. We start by elucidating the question in the most general leve1 (i.e. the relations between language and theoretical thought) but we proceed (in the 2nd and 3rd parts) to discuss what constitudes our main interest: the relations of these between language and moral thought, and of both to the historical procss. The conclusions, although not realtivist in a strict sense, emphasize the peculiarity of the ties between the historical moralities and the languages in which they are expressed. (...)

Sin resumen

Sin resumen

Sin resumen

Sin resumen

Sin resumen

Sin resumen

Sin resumen

Sin resumen

Sin resumen

Bioactive supplements display relevant therapeutic properties when properly applied according to validated molecular effects. Our previous research efforts established the basis to develop a dietary supplement based on a Rosmarinus officinalis supercritical extract. This was enriched in phenolic diterpenes (RE) with proven properties against signaling pathways involved in colon tumorigenesis, and shark liver oil rich in alkylglycerols (AKG) as a bioactive lipid vehicle to improve RE bioavailability and synergize with the potential therapeutic action of the extract. Herein, we have investigated the tolerability and safety of the supplement and the biological and molecular effects from an immuno-nutritional perspective. Sixty healthy volunteers participated in a six week, double-blind, randomized parallel pilot study with two study arms: RE-AKG capsules (CR) and control capsules (CC). Mean age (±SD) of volunteers was 28.32 (±11.39) and 27.5 (±9.04) for the control and the study groups, respectively. Safety of the CR product consumption was confirmed by analyzing liver profile, vital constants, and oxidation markers (LDLox in blood and isoprostanes and thromboxanes in urine). The following were monitored: (1) the phenotyping of plasmatic leukocytes and the ex vivo response of lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs); (2) expression of genes associated with immune-modulation, inflammation, oxidative stress, lipid metabolism, and tumorigenesis; and (3) the correlation of selected genetic variants (SNPs) with the differential responses among individuals. The lack of adverse effects on liver profile and oxidation markers, together with adequate tolerability and safe immunological adaptations, provide high-quality information for the potential use of CR as co-adjuvant of therapeutic strategies against colorectal cancer.