24 research outputs found

    El color de las aves, abstracciones de un presagio venidero de esperanzas en el horizonte

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    La presente muestra pictórica denominada “Aves”, del artista reconocido Miguel Ángel Mira Mira, nos introduce a la producción actual de la pintura abstracta salvadoreña y su creciente evolución. Mira, quien también es docente y coordinador de la opción de escultura, en la escuela de artes de la Universidad de El Salvador, es un artista constante y prolífico, no solo en la pintura, sino también en la escultura, donde ha sido homenajeado en muchas oportunidades y sus participaciones a nivel local e internacional son muy variadas

    Evolution of Native Kidney Function After Pancreas Transplantation Alone

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    peer reviewedIntroduction. This study investigated changes in kidney function over time among a cohort of patients undergoing pancreas transplantation alone (PTA) from January 2002 to December 2011. Patients and Methods. Ten of eighteen PTA patients bearing functioning grafts for at least 1 year were recruited for the analysis. Primary endpoints were changes in mean serum creatinine (SCr, mg/L) and mean estimated glomerular filtration rate (eGFR) using the 4-variable Levey-MDRD equation (mL/min/1.73 m2) comparing baseline (pretransplantation) to 6-month, 1-year, 3-year, and 5-year posttransplantation values. Mean follow-up time was 75.7 20.5 months (range, 46–106.5). Results. Baseline eGFR was 89.3 27.9 (range, 58–145). eGFR decreased to 75.7 26.2, 71 20.6, 66.5 14.8, and 62.1 11.2 at 6 months, 1, 3, and 5 years representing 15.2%, 20.5%, 15.8%, and 22.6% percentage decreases respectively (P .05 for all pairwise comparisons). The Baseline SCr was 8.6 2.3 mg/L (range, 5–13). SCr progressively increased to 10.1 3, 10.5 3.1, 10.9 3.1, and 11.3 1.7 at 6 months, 1, 3, and 5 years a 17.1%, 22%, 16.6%, and 19.9% increase respectively (P .05 for all pairwise comparisons). One of ten, 2/8, and 3/7 patients displayed an eGFR 60 at transplantation versus 3 and 5 years thereafter, respectively. No patient developed a SCr 25 mg/L or eGFR 30 or needed dialysis or kidney transplantation. Five of ten patients had micro-albuminuria or proteinuria before transplantation. Tacrolimus levels were within recommended therapeutic ranges over time. Conclusion. Kidney function deteriorated significantly after PTA. Understanding of risk factors for the development of renal impairment is important to preserve kidney function and to select appropriate candidates for PTA

    Methodology for the characterization and understanding of longitudinal wrinkling during calendering of lithium-ion and sodium-ion battery electrodes

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    "The manufacturing of lithium-ion battery (LIB) cells is following a complex process chain in which the individual process steps influence the subsequent ones. Meanwhile, increasing requirements especially concerning the battery performance, sustainability and costs are forcing the development of innovative battery materials, production technologies and battery designs. The calendering process directly affects the volumetric energy density of an electrode and therefore of a battery cell. Calendering is still challenging as it causes high stresses in the electrode that lead to defects and thus increased rejection rates. The interaction between electrode material and process as well as the formation of defects is still not fully understood, especially when new material systems are used. In this context, the sodium-ion battery (SIB) is one post-lithium battery system that is a promising option to overcome the limitations of conventional LIBs. Therefore, this paper presents a first material and machine independent methodology to describe and understand the defect type longitudinal wrinkle, which mostly appears at the uncoated current collector edge of an electrode and in running direction. The aim is to systematically characterize the longitudinal wrinkles according to their geometry. The automatic data acquisition is carried out with a laser triangulation system and a 3D scanning system. The geometry values are calculated from the raw data and correlated to selected process parameters. The methodology is applicable regardless of the material as shown by exemplary results of NMC811 cathodes for LIB and hard carbon anodes for SIB. By using two different pilot calenders it is shown, that the data acquisition can be carried out independently of the machine. The presented methodology contributes to finding solutions for the avoidance of longitudinal wrinkling in any battery electrode and therefore to reducing the rejection rate.

    Successful desensitization with human insulin in a patient with an insulin allergy and hypersensitivity to protamine: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Insulin allergy may occur in patients treated with subcutaneous applications of insulin preparations. Besides additives in the insulin preparation such as protamine, cresol, and phenol, the insulin molecule itself may be the cause of the allergy. In the latter case, therapeutic options are rare.</p> <p>Case presentation</p> <p>A 68-year-old man with poorly controlled type 2 diabetes mellitus received different insulin preparations subcutaneously while on oral medication. Six to eight hours after each subcutaneous application, he developed pruritic plaques with a diameter of >15 cm at the injection sites that persisted for several days. Allergologic testing revealed positive reactions against every insulin preparation and against protamine. Investigation of serum samples demonstrated IgG antibodies against human and porcine insulin. We treated the patient with human insulin using an ultra-rush protocol beginning with 0.004 IU and a rapid augmentation in dose up to 5 IU. Therapy was accompanied by antihistamine therapy. Subsequent conversion to therapy with glargine insulin (6 IE twice daily) was well-tolerated.</p> <p>Conclusion</p> <p>As reported in this case, desensitization with subcutaneously administered human insulin using an ultra-rush protocol in patients with an insulin allergy may present an easy form of therapy that is successful within a few days.</p

    A practical perspective on the potential of rechargeable Mg batteries

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    Emerging energy storage systems based on abundant and cost-effective materials are key to overcome the global energy and climate crisis of the 21st century. Rechargeable Magnesium Batteries (RMB), based on Earth-abundant magnesium, can provide a cheap and environmentally responsible alternative to the benchmark Li-ion technology, especially for large energy storage applications. Currently, RMB technology is the subject of intense research efforts at laboratory scale. However, these emerging approaches must be placed in a real-world perspective to ensure that they satisfy key technological requirements. In an attempt to bridge the gap between laboratory advancements and industrial development demands, herein, we report the first non-aqueous multilayer RMB pouch cell prototypes and propose a roadmap for a new advanced RMB chemistry. Through this work, we aim to show the great unrealized potential of RMBs

    A practical perspective on the potential of rechargeable Mg batteries

    Get PDF
    Emerging energy storage systems based on abundant and cost-effective materials are key to overcome the global energy and climate crisis of the 21st century. Rechargeable Magnesium Batteries (RMB), based on Earth-abundant magnesium, can provide a cheap and environmentally responsible alternative to the benchmark Li-ion technology, especially for large energy storage applications. Currently, RMB technology is the subject of intense research efforts at laboratory scale. However, these emerging approaches must be placed in a real-world perspective to ensure that they satisfy key technological requirements. In an attempt to bridge the gap between laboratory advancements and industrial development demands, herein, we report the first non-aqueous multilayer RMB pouch cell prototypes and propose a roadmap for a new advanced RMB chemistry. Through this work, we aim to show the great unrealized potential of RMBs.This work was funded by European Union's Horizon 2020 research and innovation program under the FET Proactive call with grant agreement no 824066 via the “E-MAGIC” project

    Manganese oxide catalysts for secondary zinc air batteries: from

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    An efficient, durable and low cost air cathode with low polarization between the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is essential for a high performance and durable secondary zinc-air battery. Different valence states and morphologies of MnxOy catalysts were synthetized via thermal treatment of EMD (generating Mn2O3 and Mn3O4) and acid digestion of synthetized Mn2O3 (producing a-MnO2) in order to develop an efficient Bifunctional Air Electrode (BAE). Change in the ratio H+ to Mn2O3 during the acid digestion affects the sample microporosity, the crystallographic plane distribution, as well as the physical and chemical adsorbed water which was related to defects, i.e. cation vacancies (Mn4+) and Mn3+. These characteristics were discussed and linked to the electrocatalytic activity. The best ORR performing catalyst was that with the higher surface water content (associated to material BET surface area) and a (310) surface as the 2nd more contributing plane (after 211). On the other hand, the catalyst with the higher structural water and with (110) and (200) crystallographic planes being the most intensity contributors (after 211) was the most OER active material. In this work, it was able to find a relationship between catalyst structure and air-efficiency through a volcano-like relationship between air-efficiency and surface water content. Air-efficiency (also take as round-efficiency discharge/charge in battery context) can be taken as a good descriptor of potentially good materials for Zn-Air secondary batteries technology. In this term, we were able to prepare a Bifunctional Air Electrode based on the selected a-MnO2 sample which demonstrated a roundefficiency of 53%, a DV around 1 V and a neglected loss of the charge potential (about 2.1 V) over the entire lifecycle test (more 200 cycles over 30 hours) with a capacity retention superior to 95%.European Commission H2020: Proyecto ZAS “Zinc Air Secondary innovative nanotech based batteries for efficient energy storage” (Grant Agreement 646186
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