54 research outputs found

    Dry processing and recycling of thick nacre–mimetic nanocomposites

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    Bioinspired nanocomposites with high levels of reinforcement hold great promise for future, green lightweight, and functional engineering materials, but they suffer from slow, tedious, and nonscalable preparation routes, that typically only lead to very thin films. A rapid and facile dry powder processing technique is introduced to generate bioinspired nanocomposite materials at high fractions of reinforcements (50 wt%) and with millimeter scale thickness. The process uses powder drying of vitrimer-coated nanoplatelets (nanoclay and MXene) from aqueous solution and subsequent hot-pressing. As a method of choice in industrial lightweight composite materials engineering, hot-pressing underscores a high potential to translate this approach to actual products. The use of the vitrimer chemistry with temperature-activated bond shuffling is important to facilitate smooth integration into the nanocomposite design, leading to layered nacre-inspired nanocomposites with nanoscale hard/soft order traced by X-ray diffraction and excellent mechanical properties investigated using flexural tests. Recycling by grinding and hot-pressing is possible without property loss. The compatibility with existing composite processing techniques, scalable thickness and dimensions, and recyclability open considerable opportunities for translating bioinspired nanocomposites to real-life applications

    Feedback and communication in active hydrogel spheres with pH fronts : facile approaches to grow soft hydrogel structures

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    Compartmentalized reaction networks regulating signal processing, communication and pattern formation are central to living systems. Towards achieving life-like materials, we compartmentalized urea-urease and more complex urea-urease/ester-esterase pH-feedback reaction networks into hydrogel spheres and investigate how fuel-driven pH fronts can be sent out from these spheres and regulated by internal reaction networks. Membrane characteristics are installed by covering urease spheres with responsive hydrogel shells. We then encapsulate the two networks (urea-urease and ester-esterase) separately into different hydrogel spheres to devise communication, pattern formation and attraction. Moreover, these pH fronts and patterns can be used for self-growing hydrogels, and for developing complex geometries from non-injectable hydrogels without 3D printing tools. This study opens possibilities for compartmentalized feedback reactions and their use in next generation materials fabrication

    Opioids and Ocular Surface Pathology: A Literature Review of New Treatments Horizons

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    This review discusses the role of opioids in the corneal surface and the different pathways and therapeutic methods of management. A literature review was performed using PubMed database. For the database search, the main searching words “opioid” and “topical opioid treatment” were used with the descriptors “cornea”, “ocular surface”, “neuropathic corneal pain”, “corneal sensitivity” and “naltrexone”; original scientific articles and reviews were included to achieve the purpose of the review. The endogenous opioid system has relevant functions in the organism, and in daily use, opioids are used as painkillers. However, these drugs may be employed for other indications as opioid pathways have a wide spectrum. The corneal surface for topical treatment is easily accessible, hence sparing the side effects of systemic opioids. Instillation of opioid antagonist substances, such as naltrexone, increases corneal healing rates and stimulates the division of corneal epithelium cells without deleterious effects. The natural modulation of endogenous opioids controls different forms of pain, including inflammatory and neuropathic pain, both in the ocular surface and in the central nervous system. There are diverse methods in controlling pain using opioids, especially in refractory forms. This review attempts to collect the literature about corneal surface and opioid pathways to provide an overview image and a possible direction of the news treatments

    Detrital Thermochronology Reveals Major Middle Miocene Exhumation of the Eastern Flank ofthe Andes That Predates the PampeanFlat Slab (33°–33.5°S)

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    The Cordón del Plata and Cordón del Portillo (32.6°?33.8°S) are the portions of the FrontalCordillera that straddle the transition zone between the Pampean flat‐slab subduction segment to thenorth and the normal subduction segment to the south. A complete understanding of how the FrontalCordillera developed is necessary in order to evaluate different tectonic models for the Andes along withtheir relation to subduction dynamics and contractional upper‐crustal deformation. Detrital apatite fissiontrack thermochronology of modern river sediments that drain the eastern and western slopes of theCordón del Plata and the northern Cordón del Portillo provides constraints on regional exhumationhistories. AFT data from each catchment typically contain multiple age peaks, but all have a prominent15.3?17 Ma age peak. One catchment, the Las Tunas River has a unimodal distribution at 17.0 ± 1.1 Ma, with a confined track length distribution indicative of rapid cooling at that time. These results, combined with provenance analysis in the adjacent Cacheuta Basin, indicate significant early to middle Miocene (~16 Ma) exhumation in the Cordón del Plata and the northern sector of the Cordón del Portillo. Exhumation related to rock uplift occurred prior to the ~11 Ma onset of a flat slab eometry at these latitudes, but immediately after the main east vergent contractional event in the adjacent Principal Cordillera. Such Frontal Cordillera exhumation fits in an eastward, youngest to the foreland sequence of deformation of the different morphostructural Andean units at ~33°?34°S, arguing against the recently proposed west vergent orogenic system at these latitudes.Fil: Lossada, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Geología; ArgentinaFil: Hoke, Gregory D.. Syracuse University. College Of Arts And Sciences. Department Of Earth Sciences; Estados UnidosFil: Giambiagi, Laura Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Fitzgerald, P. G.. Syracuse University. College Of Arts And Sciences. Department Of Earth Sciences; Estados UnidosFil: Mescua, Jose Francisco. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Suriano, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Aguilar, A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentin

    Geomechanical model for a seismically active geothermal field: Insights from the Tinguiririca volcanic-hydrothermal system

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    In this work, we develop a multidisciplinary approach to investigate a geothermal system located at the volcanic arc of a subduction-related orogen and highlight the interplay between active tectonism, stress field and fluid migration. By using results of field investigations from the Tinguiririca geothermal field in the High Andes of Chile (35°S), empirical analysis, and numerical models of static stress variations, we proposed a geomechanical model for evaluating the distribution of hydrothermal manifestations in a seismically-active region. The present geomechanical model follows four major steps: (1) development of the 3D structural model of fault pattern; (2) estimation of the in-situ stress field; (3) calculation of the resolved-shear-to-normal-stress ratio (slip tendency) on each fault with varying geomechanical parameters (coefficient of friction, pore pressure and cohesion) as inputs; and (4) estimation of Coulomb static stress changes as a consequence of failure in a nearby fault. Through combination of all these analyses, we characterize in detail both the active deformation in the geothermal field and its relationship with hot fluid migration.Fil: Giambiagi, Laura Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Álvarez, P.. TEHEMA S.A.; ChileFil: Spagnotto, Silvana Liz. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; ArgentinaFil: Godoy, E.. TEHEMA S.A.; ChileFil: Lossada, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Mescua, Jose Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Barrionuevo, Matías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Suriano, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentin

    Miocene deformation in the orogenic front of the Malargüe fold-and-thrust belt (35°30′–36° S): Controls on the migration of magmatic and hydrocarbon fluids

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    The integration of surface observations and sub-surface data (wellbore and seismic) from the orogenic front of the Malargüe fold-and-thrust belt allows us to study its kinematics and to interpret the local stress field and its control over fluid (magmatic and hydrocarbon) migration. Reverse faults correspond to inverted NNW-striking Mesozoic normal faults and N-S striking Cenozoic low-angle thrusts parallel to the orogen. Oblique structures with strike-slip movement are also present. The magmatic activity in the study area was strongly controlled by this structural framework and the in-situ stress field. Miocene dykes and sills were emplaced in relation to strike-slip and reverse faults, respectively. We propose an evolution of the study region from a foredeep sector, in the early-middle Miocene, to a peak in deformation in the late Miocene, and finally a waning of deformation from the Pliocene to the present. Our structural model suggests that during the evolution of the thrust front, the in-situ stress field changed from a compressional to strike-slip/compressional stress field, favouring the synchronous emplacement of sills and dykes. This alternation of stress regimes favours hydrocarbon migration through both thrusts and subvertical strike-slip faults. This exchange between both stress regimes is likely related to the similar values of the minimum (σ3) and intermediate (σ2) principal stress with an E-W oriented maximum principal stress (σ1) according to the plate convergence vector.Fil: Barrionuevo, Matías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Giambiagi, Laura Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Mescua, Jose Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Suriano, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: de la Cal, Hernán Gabriel. Roch S.A.; ArgentinaFil: Soto, J. L.. Roch S.A.; ArgentinaFil: Lossada, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentin

    Less is more : new one-step intracameral chemotherapy technique

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    © The Authors.Romanian Society of Ophthalmology.Purpose: To describe the feasibility of a new one-step approach to aspirate the aqueous and apply melphalan in a single-go without repeated entries into the anterior chamber. Methods: This retrospective non-comparative study was conducted at a referral center and included 12 patients. The one-step approach is described in a step-wise manner. No complications were observed among the patients. Results: One single injection of intracameral melphalan proved to be a successful treatment in nine cases. Two patients required a second injection, which was administered two weeks after the first one following the same technique. Conclusions: This proved to be a reasonable technique for the smooth application of melphalan in the anterior chamber studded with retinoblastoma seeds. Our outcomes revealed that it is an effective, quick, and cost-effective technique. Longer-term data collection is underway, though initial findings are encouraging.publishersversionPeer reviewe

    Cenozoic exhumation history at the core of the Andes at 31.5°S revealed by apatite fission track thermochronology

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    The Andes at ~31°-32°S lie above the Chilean-Pampean flat slab zone (~27–33°S), where several morphostructural units developed resulting in a large orogenic width. The core of the Andes is composed of the La Ramada fold-and-thrust belt in Principal Cordillera and the basement blocks of Frontal Cordillera. While rock uplift of these blocks has been broadly constrained to the middle Miocene based on structural and provenance studies, thermochronologic approaches with the potential to directly constrain the timing and amount of exhumation have not been exploited until recently. Apatite fission track data from a ~1 km vertical profile collected within the Carboniferous Pico Los Sapos Batholith in the High Andes at 31.5°S places some constraints on the thermal evolution of the region since the Paleocene. The age-elevation profile combined with inverse thermal modeling and previous AHe thermochronology, indicates an episodic cooling/exhumation history. Rocks cooled rapidly in the early Cenozoic (ca. 65-55 Ma), followed by a period of relative thermal and tectonic stability when residence in an apatite partial annealing zone (PAZ) from at least ~52 Ma to ca.15 Ma, followed by final rapid cooling beginning ca. 15 Ma. We interpret early Cenozoic and middle Miocene rapid cooling events as to be related to erosional exhumation during Andean contractional phases, associated with thrust activity along the Mondaquita Fault. The age-elevation profile is partially duplicated, with upper samples being offset ~500 m due to back-thrusting since the late Miocene. The preservation of part of an exhumed PAZ indicates 3–5 km of exhumation since the onset of rapid cooling/exhumation at ~15 Ma. Although evidence for an early Cenozoic compressional phase in the High Andes at this latitude is scarce, the occurrence of a regional K-T (~65 Ma) unconformity supports our results. The Eocene Inca phase, registered north of 30°S, on the other hand, is not shown in our thermochronological data, suggesting that this tectonic phase did not affect the core of the Andes south of this latitude. Independent geological evidence both from the hinterland (structural, geochemical and thermochronological analyses) and foreland (provenance studies) corroborate our findings of a middle Miocene deformational event in the core of the Andes at 31.5°S.Fil: Lossada, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Suriano, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Giambiagi, Laura Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Fitzgerald, Paul G.. Syracuse University; Estados UnidosFil: Hoke, Gregory. Syracuse University; Estados UnidosFil: Mescua, Jose Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Tedesco, Ana. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Arzadún, Guadalupe. lA - Te Andes S.A. Laboratorio de Termocronología de Los Andes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bordese, Sofía. lA - Te Andes S.A. Laboratorio de Termocronología de Los Andes; Argentin

    Organic transformation of lignin into mussel-inspired glues: next-generation 2K adhesive for setting corals under saltwater

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    The 2-methoxyphenol units (G-units) in lignin are modified by demethylation and oxidation to provide the activated lignin as one part of an advanced biobased two-component (2K) adhesive system, which exhibits promising shear strengths in dry and underwater applications. The activation of lignin is straightforward and generates quinones via demethylation and periodate oxidation. These act as Michael acceptors and react smoothly with multi-thiol-star polymers to yield thiol-catechol connectivities (TCCs). The mussel-inspired material platform acts as a very robust and versatile adhesive, combining low-cost and readily available lignin with multi-thiols to achieve outstanding adhesion strengths of up to 15 MPa in dry application. In particular, the 2K system is compatible with the marine biological environment and shows no acute toxicity to sensitive organisms such as fish eggs. Thus, one possible application of this material could be an adhesive for setting temperature-resistant corals in damaged reefs.Peer Reviewe

    Pseudopterygium : An Algorithm Approach Based on the Current Evidence

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    Publisher Copyright: © 2022 by the authors.Pseudopterygium is a non-progressive conjunctival adhesion to the peripheral cornea secondary to a corneal-limbus damage. According to the literature, the main etiology is a previous eye trauma. Nevertheless, this could be biased by the existence of other underdiagnosed causes of pseudopterygium, some of which may have severe consequences for the integrity of the eye and patient’s life. This comprehensive literature review was performed based on a search on the PubMed and Google Scholar databases of relevant pseudopterygium published papers according to our current knowledge and seeks to gather the existing evidence about its diverse etiologies and clinical features, as well as to propose a diagnostic algorithm to simplify its correct approach.publishersversionPeer reviewe
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