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"Rodriguez, David"
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Uncle Scrooge. The bodacious butterfly trail
Scrooge, Donald, and the nephews are off on more adventures in these tales from around the world. When Brigitta MacBridge and Huey, Dewey, and Louie find a centuries-old insect with a built-in Columbus-era treasure map, how can Scrooge McDuck not try to cash in? Then it's Scrooge and John D. Rockerduck vs. the Beagle Boys in \"The Villainous Vase Case
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A Prototype Microwave System for 3D Brain Stroke Imaging
This work focuses on brain stroke imaging via microwave technology. In particular, the open issue of monitoring patients after stroke onset is addressed here in order to provide clinicians with a tool to control the effectiveness of administered therapies during the follow-up period. In this paper, a novel prototype is presented and characterized. The device is based on a low-complexity architecture which makes use of a minimum number of properly positioned and designed antennas placed on a helmet. It exploits a differential imaging approach and provides 3D images of the stroke. Preliminary experiments involving a 3D phantom filled with brain tissue-mimicking liquid confirm the potential of the technology in imaging a spherical target mimicking a stroke of a radius equal to 1.25 cm.
Journal Article
Venting Out
We study the relationship between domestic-demand shocks and exports using data for Spanish manufacturing firms in 2002–2013. Exploiting plausibly exogenous geographical variation caused by the Great Recession, we find that firms whose domestic sales declined by more experienced a larger increase in export flows, controlling for firms’ supply determinants. This result illustrates the capacity of export markets to counteract the negative impact of local demand shocks. By structurally estimating a heterogeneous-firm model of exporting with nonconstant marginal costs of production, we conclude that these firm-level responses accounted for half of the spectacular increase in Spanish goods exports over the period 2009–2013.
Journal Article
Decellularized Cell‐Secreted Extracellular Matrices as Biomaterials for Tissue Engineering
The extracellular matrix (ECM) is the naturally secreted biomaterial scaffold that provides support and regulates key aspects of cell behavior. This dynamic and complex network of structural proteins, proteoglycans, and soluble cues defines the cell microenvironment and is essential for tissue homeostasis. Because tissue engineering approaches aim to recapitulate aspects of the microenvironment to instruct tissue regeneration, ECM‐inspired or ‐derived scaffolds are some of the earliest tissue‐engineered constructs reported. However, conventional single‐protein constructs fail to provide the biochemical and structural complexity of the native ECM. Decellularized ECM is under investigation to improve cell adhesion, cell remodeling, migration, proliferation, and differentiation within tissue‐engineered constructs. However, challenges associated with poor mechanical properties and inherent chemical instability compared to synthetic or other natural polymers require additional considerations. This review describes the bioactive properties of ECM, current strategies to efficiently decellularize cell‐secreted and tissue‐derived ECM, standard fabrication techniques for ECM constructs, and current developments in the field of ECM‐based musculoskeletal platforms. The extracellular matrix (ECM) is a naturally secreted biomaterial scaffold that provides support and regulates key aspects of cell behavior. This review describes the bioactive properties of ECM, current strategies to decellularize cell‐secreted and tissue‐derived ECM, standard fabrication techniques for ECM constructs, and current developments in the field of ECM‐based musculoskeletal platforms.
Journal Article
Multistep protein unfolding during nanopore translocation
Cells are divided into compartments and separated from the environment by lipid bilayer membranes. Essential molecules are transported back and forth across the membranes. We have investigated how folded proteins use narrow transmembrane pores to move between compartments. During this process, the proteins must unfold. To examine co-translocational unfolding of individual molecules, we tagged protein substrates with oligonucleotides to enable potential-driven unidirectional movement through a model protein nanopore, a process that differs fundamentally from extension during force spectroscopy measurements. Our findings support a four-step translocation mechanism for model thioredoxin substrates. First, the DNA tag is captured by the pore. Second, the oligonucleotide is pulled through the pore, causing local unfolding of the C terminus of the thioredoxin adjacent to the pore entrance. Third, the remainder of the protein unfolds spontaneously. Finally, the unfolded polypeptide diffuses through the pore into the recipient compartment. The unfolding pathway elucidated here differs from those revealed by denaturation experiments in solution, for which two-state mechanisms have been proposed.
The unfolding pathway of a model protein during translocation through a transmembrane pore differs from that in solution.
Journal Article
Dexamethasone protects retinal ganglion cells but not Müller glia against hyperglycemia in vitro
Diabetic retinopathy (DR) is a common complication of diabetes, for which hyperglycemia is a major etiological factor. It is known that retinal glia (Müller cells) and retinal ganglion cells (RGCs) are affected by diabetes, and there is evidence that DR is associated with neural degeneration. Dexamethasone is a glucocorticoid used to treat many inflammatory and autoimmune conditions, including several eye diseases like DR. Thus, our goal was to study the effect of dexamethasone on the survival of RGCs and Müller glial cells isolated from rat retinas and maintained in vitro under hyperglycemic conditions. The behavior of primary RGC cell cultures, and of mixed RGC and Müller cell co-cultures, was studied in hyperglycemic conditions (30 mM glucose), both in the presence and absence of Dexamethasone (1 μM). RGC and Müller cell survival was evaluated, and the conditioned media of these cultures was collected to quantify the inflammatory cytokines secreted by these cells using a multiplex assay. The role of IL-1β, IL-6 and TNFα in RGC death was also evaluated by adding these cytokines to the co-cultures. RGC survival decreased significantly when these cells were grown in high glucose conditions, reaching 54% survival when they were grown alone and only 33% when co-cultured with Müller glia. The analysis of the cytokines in the conditioned media revealed an increase in IL-1β, IL-6 and TNFα under hyperglycemic conditions, which reverted to the basal concentration in co-cultures maintained in the presence of dexamethasone. Finally, when these cytokines were added to co-cultures they appeared to have a direct effect on RGC survival. Hence, these cytokines could be implicated in the death of RGCs when glucose concentrations increase and dexamethasone might protect RGCs from the cell death induced in these conditions.
Journal Article
Cellular and molecular features of EDC exposure: consequences for the GnRH network
The onset of puberty and the female ovulatory cycle are important developmental milestones of the reproductive system. These processes are controlled by a tightly organized network of neurotransmitters and neuropeptides, as well as genetic, epigenetic and hormonal factors, which ultimately drive the pulsatile secretion of gonadotropin-releasing hormone. They also strongly depend on organizational processes that take place during fetal and early postnatal life. Therefore, exposure to environmental pollutants such as endocrine-disrupting chemicals (EDCs) during critical periods of development can result in altered brain development, delayed or advanced puberty and long-term reproductive consequences, such as impaired fertility. The gonads and peripheral organs are targets of EDCs, and research from the past few years suggests that the organization of the neuroendocrine control of reproduction is also sensitive to environmental cues and disruption. Among other mechanisms, EDCs interfere with the action of steroidal and non-steroidal receptors, and alter enzymatic, metabolic and epigenetic pathways during development. In this Review, we discuss the cellular and molecular consequences of perinatal exposure (mostly in rodents) to representative EDCs with a focus on the neuroendocrine control of reproduction, pubertal timing and the female ovulatory cycle.Exposure to environmental pollutants such as endocrine-disrupting chemicals (EDCs) during critical periods of development can have long-term reproductive consequences. This Review discusses the cellular and molecular consequences of perinatal exposure EDCs with a focus on the neuroendocrine control of reproduction.
Journal Article
Evolution of Indoor Positioning Technologies: A Survey
Indoor positioning systems (IPS) use sensors and communication technologies to locate objects in indoor environments. IPS are attracting scientific and enterprise interest because there is a big market opportunity for applying these technologies. There are many previous surveys on indoor positioning systems; however, most of them lack a solid classification scheme that would structurally map a wide field such as IPS, or omit several key technologies or have a limited perspective; finally, surveys rapidly become obsolete in an area as dynamic as IPS. The goal of this paper is to provide a technological perspective of indoor positioning systems, comprising a wide range of technologies and approaches. Further, we classify the existing approaches in a structure in order to guide the review and discussion of the different approaches. Finally, we present a comparison of indoor positioning approaches and present the evolution and trends that we foresee.
Journal Article
An Icteric Tongue
A 12-year-old boy presented with a 4-day history of sore throat and dark urine. He was found to have jaundice with an icteric tongue, and the hemoglobin level was 6.1 g per deciliter. A diagnosis of cold agglutinin, EBV-induced acute hemolytic anemia was made.
Journal Article
Review of Microwave Near-Field Sensing and Imaging Devices in Medical Applications
Microwaves can safely and non-destructively illuminate and penetrate dielectric materials, making them an attractive solution for various medical tasks, including detection, diagnosis, classification, and monitoring. Their inherent electromagnetic properties, portability, cost-effectiveness, and the growth in computing capabilities have encouraged the development of numerous microwave sensing and imaging systems in the medical field, with the potential to complement or even replace current gold-standard methods. This review aims to provide a comprehensive update on the latest advances in medical applications of microwaves, particularly focusing on the near-field ones working within the 1–15 GHz frequency range. It specifically examines significant strides in the development of clinical devices for brain stroke diagnosis and classification, breast cancer screening, and continuous blood glucose monitoring. The technical implementation and algorithmic aspects of prototypes and devices are discussed in detail, including the transceiver systems, radiating elements (such as antennas and sensors), and the imaging algorithms. Additionally, it provides an overview of other promising cutting-edge microwave medical applications, such as knee injuries and colon polyps detection, torso scanning and image-based monitoring of thermal therapy intervention. Finally, the review discusses the challenges of achieving clinical engagement with microwave-based technologies and explores future perspectives.
Journal Article