235 research outputs found

    La plataforma submarina y la costa atlántica Argentina durante los últimos 22.000 años

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    La glaciaciones ocurridas en la región expusieron en diferente grado la actual plataforma continental Argentina (océano Atlántico sudoccidental). Este trabajo de divulgación científica da a conocer un modelo de evolución paleogeográfica de las costas de la Pampa y la Patagonia, y brinda la posibilidad de localizar temporalmente la formación de los principales rasgos costeros del extremo sur de América del sur. Se incluyen además otras lecturas sugeridas relacionadas al tema

    The southernmost evidence for an interglacial transgression (Sangamon?) in South America. First record of upraised Pleistocene marine deposits in Isla Navarino (Beagle Channel, Southern Chile)

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    Marine beach shell deposits recording a pre-Holocene marine transgression have been found at the southern shore of the Beagle Channel, Isla Navarino, Chile. These shelly deposits were dated by AMS at 41,700 14C years B.P., which clearly indicates a Pleistocene age. A sample of wood underlying the marine deposits yielded an infinite age (gt;46.1 14C ka B.P.). If the date on the shells is considered as a minimum, infinite age, together with the elevation of these marine units above present mean tide sea level (at least 10 m a.s.l.) they may be considered as deposited during the Last Interglacial, of Sangamon age (Marine Isotope Stage -MIS- 5e) or during a younger phase of MIS 5. The fossil content of this unit is similar to the fauna living in this region today, supporting also an Interglacial palaeoenvironment interpretation. If this interpretation and the dating proposal are correct, this is the first reported record of Sangamon deposits in the Beagle Channel and the southernmost Last Interglacial site (MIS 5) in South America

    Protocolo de indução de cetose sub-clínica em ovelhas prenhes e seu efeito sobre parâmetros metabólicos.

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    O objetivo deste estudo foi avaliar a eficiência de um protocolo de indução de cetose sub-clínica em ovelhas em terço final de gestação, através de seu efeito sobre parâmetros bioquímicos

    Patterns of MUC1 tissue expression defined by an Anti-MUC1 cytoplasmic tail monoclonal antibody in breast cancer

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    Our aim was to determine the pattern of expression of MUC1 mucin cytoplasmic tail (MUC1 CT) in breast carcinoma. A total of 98 invasive breast adenocarcinoma tumor samples were assayed by immunohistochemical (IHC) analysis. The pattern of reaction was classified as membrane, cytoplasmic, or mixed. Subcellular fractions were prepared after SDS-PAGE and Western blotting. The antibodies employed were anti-MUC1 CT (CT2 monoclonal antibody, MAb) and C595 MAb against the extracellular MUC1 core protein. With the CT2 MAb, IHC showed a high percentage of positive staining in 93% of specimens, with membrane staining the most common pattern observed. C595 MAb was reactive in 73% of specimens. Similar percentages of membrane and cytoplasmic staining were found, mainly in a mixed pattern. Western blotting showed different bands. With the CT2 MAb, the membrane fraction showed the most intense reaction; a strong band of reaction was detected at approximately <30 kD. With the C595 MAb, in most cases a double band at 200 kD was found. In breast epithelium, the pattern of MUC1 CT expression may constitute an indicator of MUC1 production because it does not depend on glycosylation. The pattern and extension of MUC1 CT positivity do not vary according to the histopathological subtype of the tumor.Facultad de Ciencias MédicasCentro de Investigaciones Inmunológicas Básicas y Aplicada

    Patterns of MUC1 tissue expression defined by an Anti-MUC1 cytoplasmic tail monoclonal antibody in breast cancer

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    Our aim was to determine the pattern of expression of MUC1 mucin cytoplasmic tail (MUC1 CT) in breast carcinoma. A total of 98 invasive breast adenocarcinoma tumor samples were assayed by immunohistochemical (IHC) analysis. The pattern of reaction was classified as membrane, cytoplasmic, or mixed. Subcellular fractions were prepared after SDS-PAGE and Western blotting. The antibodies employed were anti-MUC1 CT (CT2 monoclonal antibody, MAb) and C595 MAb against the extracellular MUC1 core protein. With the CT2 MAb, IHC showed a high percentage of positive staining in 93% of specimens, with membrane staining the most common pattern observed. C595 MAb was reactive in 73% of specimens. Similar percentages of membrane and cytoplasmic staining were found, mainly in a mixed pattern. Western blotting showed different bands. With the CT2 MAb, the membrane fraction showed the most intense reaction; a strong band of reaction was detected at approximately <30 kD. With the C595 MAb, in most cases a double band at 200 kD was found. In breast epithelium, the pattern of MUC1 CT expression may constitute an indicator of MUC1 production because it does not depend on glycosylation. The pattern and extension of MUC1 CT positivity do not vary according to the histopathological subtype of the tumor.Facultad de Ciencias MédicasCentro de Investigaciones Inmunológicas Básicas y Aplicada

    Middle pleistocene glaciation in Patagonia dated by cosmogenic-nuclide measurements on outwash gravels

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    The well-preserved glacial record in Argentine Patagonia offers a ~ 1 Ma archive of terrestrial climate extremes in southern South America. These glacial deposits remain largely undated beyond the range of radiocarbon dating at ca. 40 ka. Dating old glacial deposits (> several 105 a) by cosmogenic surface exposure methods is problematic because of the uncertainty in moraine degradation and boulder erosion rates. Here, we show that cobbles on outwash terraces can reliably date ‘old’ glacial deposits in the Lago Pueyrredón valley, 47.5° S, Argentina. Favorable environmental conditions (e.g., aridity and strong winds) have enabled continuous surface exposure of cobbles and preservation of outwash terraces. The data demonstrate that nuclide inheritance is negligible and we therefore use the oldest surface cobbles to date the deposit. 10Be concentrations in outwash cobbles reveal a major glacial advance at ca. 260 ka, concurrent with Marine Isotope Stage 8 (MIS 8) and dust peaks in Antarctic ice cores. A 10Be concentration depth-profile in the outwash terrace supports the age and suggests a low terrace erosion rate of ca. 0.5 mm ka− 1. We compare these data to exposure ages obtained from associated moraines and find that surface boulders underestimate the age of the glaciation by ~ 100 ka; thus the oldest boulders in this area do not date closely moraine deposition. The 10Be concentration in moraine cobbles help to constrain moraine degradation rates. These data together with constraints from measured 26Al/10Be ratios suggest that all moraine boulders were likely exhumed after original deposition. We determine the local Last Glacial Maximum (LGM) occurred at ~ 27–25 ka, consistent with the maximum LGM in other parts of Patagonia

    Paleo-landscapes of the Northern Patagonian Massif, Argentina

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    Fil: Aguilera, Emilia Yolanda. Instituto de Geomorfología y Suelos (IGS). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Rabassa, Jorge. Laboratorio de Geomorfología y Cuaternario. CADIC. Universidad Nacional de Tierra del Fuego; ArgentinaFil: Aragón, Eugenio. Centro de Investigaciones Geológicas (CIG). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

    Electromagnetic Assessment of UHF-RFID Devices in Healthcare Environment

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    In this work, the evaluation of electromagnetic effect of Ultra High Frequency Radio Frequency Identification (UHF-RFID) passive tags used in the healthcare environment is presented. In order to evaluate exposure levels caused by EM field (865–868 MHz) of UHF-RFID readers, EM measurements in an anechoic chamber and in a real medical environment (Hospital Universitario de Canarias), as well as simulations by 3D Ray Launching algorithm, and of biophysical exposure effects in human models are presented. The results obtained show that the EM exposure is localized, in close vicinity of RFID reader and inversely proportional to its reading range. The EM exposure levels detected are sufficient to cause EM immunity effects in electronic devices (malfunctions in medical equipment or implants). Moreover, more than negligible direct effects in humans (exceeding relevant SAR values) were found only next to the reader, up to approximately 30% of the reading range. As a consequence, the EM risk could be firstly evaluated based on RFID parameters, but should include an in situ exposure assessment. It requires attention and additional studies, as increased applications of monitoring systems are observed in the healthcare sector—specifically when any system is located close to the workplace that is permanently occupied.This work was supported by Instituto de Salud Carlos III project “Electromagnetic “Characterization in Smart Environments of Healthcare, and their involvement in Personal, Occupational, and Environmental Health” (PI14CIII/00056) https://portalfis.isciii.es/es/Paginas/DetalleProyecto. aspx?idProyecto=PI14CIII%2f00056 (accessed on 24 July 2022), and project “ (PI19CIII/00033) TMPY 508/19 “ Metrics development for electromagnetic safety assessment in healthcare centers in the context of 5G“ https://portalfis.isciii.es/es/Paginas/DetalleProyecto.aspx?idProyecto=PI19 CIII%2f00033, (accessed on 24 July 2022) from Sub-Directorate-General for Research Assessment and Promotion. The results of a research task (II.PB.15) carried out within the National Programme “Improvement of safety and working conditions” partly supported in Poland in 2020-2022-within the scope of research and development-by the National Centre for Research and Development were also included.S
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