223 research outputs found

    Mesenchymal stem cells for the treatment of systemic lupus erythematosus: is the cure for connective tissue diseases within connective tissue?

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    Mesenchymal stem cells (MSCs) are now known to display not only adult stem cell multipotency but also robust anti-inflammatory and regenerative properties. After widespread in vitro and in vivo preclinical testing in several autoimmune disease models, allogenic MSCs have been successfully applied in patients with severe treatment-refractory systemic lupus erythematosus. The impressive results of these uncontrolled phase I and II trials - mostly in patients with non-responding renal disease - point to the need to perform controlled multicentric trials. In addition, they suggest that there is much to be learned from the basic and clinical science of MSCs in order to reap the full potential of these multifaceted progenitor cells in the treatment of autoimmune diseases

    A Method for Systematic Adaptation and Synchronization of Healthcare Processes

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    International organizations, as the World Health Organization (WHO) and national governments are constantly defining (or modifying) new healthcare protocols and procedures. Those changes have a significant impact, on one side, on the organizational concerns of a great number of healthcare institutions and centers, and on the other side, on their health information systems that need to be adapted according to the new (or modified) procedures. Administrative workflows are commonly defined by a high level entity and they must then be applied on different institutions ruled by this high level entity. Those workflows must then be adapted to the particular circumstances of each institution, complying with the general regulations of the process established at the top level. This problem, called Hierarchical Adaptation Problem, also implies establishing the methods to evolve together the high level regulation. Such methods must maintain the consistency among the different levels by means of the propagation of the changes to all the different adaptations of the original workflow. To solve this problem, this work introduces the Hierarchical Adaptation Method. A method based on ontologies to define the rules that must be satisfied by a generic workflow to be considered adaptable to different application cases and the rules that must be satisfied by its adapted versions. Moreover, it provides the operations to facilitate both adaptation of administrative workflows and propagation of changes

    CompareML: A Novel Approach to Supporting Preliminary Data Analysis Decision Making

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    There are a large number of machine learning algorithms as well as a wide range of libraries and services that allow one to create predictive models. With machine learning and artificial intelligence playing a major role in dealing with engineering problems, practising engineers often come to the machine learning field so overwhelmed with the multitude of possibilities that they find themselves needing to address difficulties before actually starting on carrying out any work. Datasets have intrinsic properties that make it hard to select the algorithm that is best suited to some specific objective, and the ever-increasing number of providers together make this selection even harder. These were the reasons underlying the design of CompareML, an approach to supporting the evaluation and comparison of machine learning libraries and services without deep machine learning knowledge. CompareML makes it easy to compare the performance of different models by using well-known classification and regression algorithms already made available by some of the most widely used providers. It facilitates the practical application of methods and techniques of artificial intelligence that let a practising engineer decide whether they might be used to resolve hitherto intractable problems. Thus, researchers and engineering practitioners can uncover the potential of their datasets for the inference of new knowledge by selecting the most appropriate machine learning algorithm and determining the provider best suited to their data

    Unexpected Changes in the Population of Coordination Isomers for the Lanthanide Ion Complexes of DOTMA–Tetraglycinate

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    [Abstract] Lanthanide complexes with DOTA–tetraglycinate (DOTA-(gly)4) heavily favor the square antiprismatic (SAP) coordination isomer in aqueous solution, a structural feature that has made them useful as water-based paraCEST agents. In an effort to create amide-based paraCEST agents with rapid water exchange rates, we prepared the analogous tetraglycinate complexes with DOTMA, a ligand known to favor the twisted square antiprismatic (TSAP) coordination structures. Unexpectedly, NMR investigations show that the LnDOTMA–(gly)4 complexes, like the LnDOTA–(gly)4 complexes, also favor the SAP isomers in solution. This observation led to density functional theory (DFT) calculations in order to identify the energy terms that favor the SAP structures in lanthanide complexes formed with macrocyclic DOTA– and DOTMA–tetraamide ligands. The DFT calculations revealed that, regardless the nature of the ligand, the TSAP isomers present more negative hydration energies than the SAP counterparts. The extent to which the TSAP isomer is stabilized varies, however, depending on the ligand structure, resulting in different isomeric populations in solution.Estados Unidos. National Institutes of Health; CA115531Estados Unidos. National Institutes of Health; EB015908Estados Unidos. National Institutes of Health; EB004582Estados Unidos. Robert A. Welch Foundation; AT-584Ministerio de Economía y Competitividad; CTQ2013-43243-PMinisterio de Economía y Competitividad; CTQ2015-71211-RED

    Physicochemical, structural, mechanical, and tribological characteristics of Si3N4–MoS2 thin films deposited by reactive magnetron sputtering

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    AbstractSi3N4 coatings show outstanding performance in wear and corrosion resistance of cutting tools at high temperatures, up to 1000°C and above. In addition, the incorporation of minor concentrations of MoS2 in Si3N4 could reduce the friction coefficient and preserve sufficiently high hardness values. In the present work, Si3N4–MoS2 thin films were deposited on C and Si (001) substrates by RF and DC reactive deposition magnetron sputtering from Si and MoS2 targets in a Ar/N2 plasma, with different low MoS2 amounts. The thin films were characterized by nanoindentation at different temperatures from 23°C to 400°C and sliding friction and nanoscratch tests at a constant temperature of 23°C. Several different analytical techniques were also employed to characterize the thin films. In the whole layer both Si3N4 and MoS2 compounds are stoichiometric and the structure is amorphous and homogenous. Although the hardness is roughly constant in the here investigated MoS2 concentration range at constant temperature, the lowest amount of MoS2 (0.2at.%) increases substantially the hardness of Si3N4–MoS2 thin films at 23°C. The hardness of Si3N4–MoS2 thin films decreases with the increase of temperature. The friction coefficient decreases substantially for MoS2 concentrations between 0.2 and 0.3at.% and the annealing process does not modify such behavior. The 24h annealing performed during hardness measurements, up to 400°C, induced thermally-activated processes in the thin films, which modify the critical load, hardness, and reduced elastic modulus of the thin film when measured at 23°C

    El modelo sistémico de aprendizaje y enseñanza, como apoyo en la inserción laboral

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    The main objective of the research was to find out how the systemic process influences with the teaching and learning approach, in the labor inclusion of graduates of the Faculty of Law of the National University Hermilio Valdizán. To achieve this, the study was developed based on a descriptive explanatory type, under a non-experimental, correlational and cross-sectional design, for which we worked with a population of 121 graduates and the sample consisted of 37 graduates from the years 2016 and 2017, being of the non-probabilistic type, which were constructed two questionnaires, a questionnaire to measure the systematic teaching-learning process variable, another questionnaire to measure the job placement opportunity variable, all to qualify the level of influence. Sperman's Ro test was applied to evaluate the hypothesis. As a result, our results confirmed the study hypothesis, showing that the systemic teaching-learning process shows a significant relationship with job placement and that there is a positive influence between both variables. Reaching the conclusion that exercising a systemic process in teaching and learning generates opportunity in labor inclusion.La investigación tuvo como objetivo principal buscar cómo influye el proceso sistémico con el enfoque de enseñanza y aprendizaje, en la inclusión laboral de los egresados de la Facultad de Derecho de la Universidad Nacional Hermilio Valdizán. Para lograrlo, se desarrolló el estudio en base a tipo descriptivo explicativo, bajo un diseño no experimental, correlacional  y de tipo transversal, para lo cual se trabajó con una población de 121 egresados y la muestra estuvo constituida por 37 egresados de los años 2016 y 2017, siendo del tipo no probabilístico, los cuales se construyeron dos cuestionarios, un cuestionario para medir la variable proceso sistemático de enseñanza-aprendizaje, otro cuestionario para medir la variable oportunidad de inserción laboral, todo ello para calificar el nivel de influencia. Para evaluar la hipótesis se aplicó la prueba Ro de Sperman. A raíz de ello nuestros resultados confirmaron la hipótesis de estudio, demostrando que el proceso sistémico de enseñanza-aprendizaje muestra una relación significativa con la inserción laboral y que existe influencia positiva entre ambas variables. Llegando a la conclusión que ejercer un proceso sistémico en la enseñanza y aprendizaje genera oportunidad en la inclusión laboral

    Spectra of PP-Wave Limits of M-/Superstring Theory on AdS_p x S^q Spaces

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    In this paper we show how one can obtain very simply the spectra of the PP-wave limits of M-theory over AdS_7(4) x S^4(7) spaces and IIB superstring theory over AdS_5 x S^5 from the oscillator construction of the Kaluza-Klein spectra of these theories over the corresponding spaces. The PP-wave symmetry superalgebras are obtained by taking the number P of ``colors'' of oscillators to be large (infinite). In this large P limit, the symmetry superalgebra osp(8*|4) of AdS_7 x S^4 and the symmetry superalgebra osp(8|4,R) of AdS_4 x S^7 lead to isomorphic PP-wave algebras, which is the semi-direct sum of su(4|2) with H^(18,16), while the symmetry superalgebra su(2,2|4) of AdS_5 x S^5 leads to the semi-direct sum of [psu(2|2) + psu(2|2) + u(1)] with H^(16,16) as its PP-wave algebra [H^(m,n) denoting a super-Heisenberg algebra with m bosonic and n fermionic generators]. The zero mode spectra of M-theory or IIB superstring theory in the PP-wave limit corresponds simply to the unitary positive energy representations of these algebras whose lowest weight vector is the Fock vacuum of all the oscillators. General positive energy supermultiplets including those corresponding to higher modes can similarly be constructed by the oscillator method.Comment: Typos corrected; references added; minor modifications to improve presentation; 37 pages, LaTeX fil

    Body weight, cardiac index values, and hematocrit and haemoglobin levels in two turkey commercial lines

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    El presente estudio tuvo como objetivo comparar el peso corporal, así como índices cardiacos, hematocrito y hemoglobina como indicadores de trabajo cardiaco de dos líneas de pavos de engorde criados a nivel del mar. Se trabajó con 35 pavos de la línea BUT y 35 de la línea Hybrid. El peso corporal (PC) se registró desde la 4ª a la 14ª semana de edad en que fueron beneficiados. En ese momento, se tomó una muestra de sangre para determinar el hematocrito y la hemoglobina; además, se extrajeron los corazones y se determinaron las relaciones de peso ventrículo derecho/ventrículo total (VD/VT), peso ventrículo izquierdo/ventrículo total (VI/VT), peso ventrículo izquierdo + septo/ ventrículo total (VI+S/VT), VI/PC, VD/PC, VI+S/PC y VT/PC. El peso corporal y la hemoglobina en pavos BUT fueron superiores (p<0.05), mientras que el hematocrito fue mayor (p<0.05) en pavos de la línea Hybrid. No se encontraron diferencias de los índices VD/VT, VI/VT, (VI+S)/VT y VD/PC entre las dos líneas, pero se encontró valores superiores (p<0.05) para las relaciones VI/PC, (VI+S)/PC y VT/PC en la línea BUT, concordante con la ganancia de peso.The study aimed to compare the body weight, and cardiac indices, hematocrit and hemoglobin as indicators of cardiac activity of two turkey commercial lines reared at sea level. Thirty five turkeys from each line were used in the study. Body weight (PC) was recorded from the 4th to the 14th week of age where birds were slaughtered. There, blood samples were collected for measuring hematocrit and hemoglobin levels. Also, hearts were collected to determine the following ratios: weight of right ventricle/total ventricle (VD/VT), weight of left ventricle/total ventricle (VI/VT), weight of left ventricle + septum/ total ventricle (VI+S/VT), VI/PC, VD/PC, VI+S/PC, and VT/PC. Body weight and haemoglobin in BUT turkeys were higher (p<0.05) and hematocrit was higher (p<0.05) in Hybrid turkeys. No statistical differences were found on VD/VT, VI/VT, (VI+S)/VT, and VD/PC between lines, but higher values were observed (p<0.05) for VI/PC, (VI+S)/PC, and VT/PC in BUT turkeys, compatible with body weight gain

    3D Printed hydroponic system

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    Hydroponic systems have been around for many years and there is a large variety of designs. This project approaches the design of a stackable hydroponic system for domestic use aiming for high yield. The 3-D printed prototype consisted of cylindrical elements each with three entries for seeding. These elements can be stacked up and rotated around one another providing configuration flexibility. In addition, the cap of our system is a half cylindrical element. A preliminary test included the use of Rockwool to grow coriander for 14 days. Being a prototype, it is still necessary to optimize the design, fine-tune its operation beyond its initial feasibility to both, maximize yield and minimize cost, which implies compromising on these two conflicting objectives.Los sistemas hidropónicos existen desde hace ya varios años en una amplia variedad de diseños y configuraciones. El proyecto que aquí se describe comprende el diseño de un sistema hidropónico modular apilable para uso doméstico, con miras a que sea uno con alta productividad. Una impresora 3D se utilizó para desarrollar el prototipo que consta de elementos cilíndricos, cada uno con tres receptáculos. A los elementos cilíndricos apilables se les puede rotar con respecto de su eje, añadiendo así mayor flexibilidad de configuración. Convenientemente, la tapa del sistema está formada por medio elemento cilíndrico. Para la prueba preliminar que aquí se describe, se depositaron semillas de cilantro por un período de 14 días en Rockwool. En su fase prototípica, se determinó la factibilidad del sistema, aunque se reconoce que es aún necesario optimizar el diseño y afinar su operación. Esto implicará conciliar dos objetivos en conflicto: maximizar la productividad del sistema y minimizar su costo total

    Describing complex interactions of social-ecological systems for tipping point assessments: an analytical framework

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    Humans play an interconnecting role in social-ecological systems (SES), they are part of these systems and act as agents of their destruction and regulation. This study aims to provide an analytical framework, which combines the concept of SES with the concept of tipping dynamics. As a result, we propose an analytical framework describing relevant dynamics and feedbacks within SES based on two matrixes: the “tipping matrix” and the “cross-impact matrix.” We take the Southwestern Amazon as an example for tropical regions at large and apply the proposed analytical framework to identify key underlying sub-systems within the study region: the soil ecosystem, the household livelihood system, the regional social system, and the regional climate system, which are interconnected through a network of feedbacks. We consider these sub-systems as tipping elements (TE), which when put under stress, can cross a tipping point (TP), resulting in a qualitative and potentially irreversible change of the respective TE. By systematically assessing linkages and feedbacks within and between TEs, our proposed analytical framework can provide an entry point for empirically assessing tipping point dynamics such as “tipping cascades,” which means that the crossing of a TP in one TE may force the tipping of another TE. Policy implications: The proposed joint description of the structure and dynamics within and across SES in respect to characteristics of tipping point dynamics promotes a better understanding of human-nature interactions and critical linkages within regional SES that may be used for effectively informing and directing empirical tipping point assessments, monitoring or intervention purposes. Thereby, the framework can inform policy-making for enhancing the resilience of regional SES
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