470 research outputs found

    Drug complexation and physicochemical properties of vinylpyrrolidone-N, N′-dimethylacrylamide copolymers

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    Solid dispersions of the nonsteriodal antiin-flammatory drug (NSAID) 2′,4′-difluoro-4-hydroxy-(1,1′-biphenyl)-3-carboxylic acid (DIF) with the water-soluble random copolymer poly(N-vinyl-2-pyrrolidone-co-N, N′-dimethylacrylamide) (VP-co-DMAm) were prepared by the solvent method (coevaporates) and melting DIP/VP-co-DMAm (cofused) physical mixtures. Differential scanning calorimetry (DSC), infrared spectroscopy (FTIR), and X-ray diffraction (XRD) were used to elucidate the possible interaction between the NSAID drug and VP-co-DMAm in cofused and coevaporated polymer-drug solid dispersions. The XRD and FTIR studies suggest the presence of physical interactions with formation of a charge transfer complex between DIF and the VP-co-DMAm copolymers as a consequence of the coevaporation or cofusion processes. In solution, dynamic and equilibrium solubility studies were determined to elucidate the mechanism of interaction between DIP and VP-co-DMAm copolymers. Thermodynamics data about the DIP: VP-co-DMAm dissolution process indicate that the coevaporated systems are more stable that the cofused systems. The dissolution of the cofused and coevaporated systems was diffusion controlled and the dissolution kinetics followed the Noyes-Whitney and the Levich equations. Molecular simulations using semiempirical quantum chemical calculations reinforce the experimental results, suggesting that the improvement in the DIF solubility could be attributed to the charge transfer complex formation between the drug and VP-co-DMAm copolymers.Fil: De Queiroz, Alvaro A.A.. Universidade Federal de Itajubá; BrasilFil: França, Écio J.. Universidade Federal de Itajubá; BrasilFil: Abraham, Gustavo Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Roman, Julio San. Instituto en Ciencia y Tecnología de Polímeros; Españ

    An updated catalog of M33 clusters and candidates: UBVRIUBVRI photometry, and some statistical results

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    We present UBVRIUBVRI photometry for 392 star clusters and candidates in the field of M33, which are selected from the most recent star cluster catalog. In this catalog, the authors listed star clusters' parameters such as cluster positions, magnitudes and colors in the UBVRIJHKsUBVRIJHK_s filters, and so on. However, a large fraction of objects in this catalog do not have previously published photometry. Photometry is performed using archival images from the Local Group Galaxies Survey, which covers 0.8 deg2^2 along the major axis of M33. Detailed comparisons show that, in general, our photometry is consistent with previous measurements. Positions (right ascension and declination) for some clusters are corrected here. Combined with previous literature, we constitute a large sample of M33 star clusters. Based on this cluster sample, we present some statistical results: none of the M33 youngest clusters (107\sim 10^7 yr) have masses approaching 10510^5 MM_{\odot}; roughly half the star clusters are consistent with the 10410^4 to 10510^5 MM_{\odot} mass models; the continuous distribution of star clusters along the model line indicates that M33 star clusters have been formed continuously from the epoch of the first star cluster formation until recent times; there are 50\sim 50 star clusters which being overlapped with the Galactic globular clusters on the color-color diagram, and these clusters are old globular clusters candidates in M33.Comment: Accepted for Publication in AJ, 22 pages, 12 figures and 9 table

    Grain yield definition under environmental restrictions

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    Trigo pan y cebada cervecera son los principales cereales de invierno sembrados en Argentina, en consonancia con su relevancia a nivel mundial. Durante el último quinquenio, el rendimiento medio logrado a nivel productivo en Argentina ha sido para trigo de 2972 kg ha-1 y para cebada de 3596 kg ha-1 , un -9% y +24% respecto al rendimiento medio mundial para el mismo período en cada cultivo. Desde 1960 a la actualidad, el aumento de rendimiento logrado en Argentina presentó una tasa de 32 kg ha-1 año-1 para trigo y de 51 kg ha-1 año-1 para cebada. Alrededor de un tercio del aumento de rendimiento logrado a campo estuvo dado por el progreso genético, en ambos cultivos, pero con fuertes variaciones a lo largo de los años. Tanto en trigo como en cebada el aumento de rendimiento por progreso genético estuvo asociado a un aumento en el número de granos m-2 , sin una tendencia definida en el peso de los granos. Las deficiencias nitrogenadas, las altas temperaturas, y los eventos de anegamiento son algunos de los estreses abióticos a los que están expuestos ambos cultivos en condiciones de campo. En el presente trabajo se describe el impacto de dichos estreses sobre la definición del rendimiento en trigo y cebada, en base a resultados propios obtenidos por los autores del presente trabajo. El número de granos logrados por m2 fue el componente numérico que explicó el rendimiento independientemente de la especie y de la naturaleza del estrés. Dado que la definición del número de granos queda supeditada a la condición ambiental alrededor de antesis, el uso de modelos de simulación es una herramienta para evaluar cuándo ocurrirá dicho evento.Bread wheat and malting barley are the main winter cereals sown in Argentine, in line with its worldwide relevance. During the last five years, the average grain yield achieved in Argentina has been 2972 kg ha-1 for wheat and 3596 kg ha-1 for barley, -9% and +24% relative to worldwide average grain yield for the same period. Yield increase achieved in Argentina from 1960 to the present time presented a rate of 32 kg ha-1 year-1 for wheat and 51 kg ha-1 year-1 for barley. About one third of the yield increase achieved in the field was explained by genetic progress, in both crops, but with strong variability over the years. The increase in grain yield due to genetic progress was associated with an increase in grain number m-2 in both wheat and barley, without a clear trend in weight grain. Nitrogenous deficiencies, high temperatures periods, and waterlogging events are some of the main abiotic stresses to which both crops are exposed under field conditions. In this work we described the impact of these stresses on the definition of grain yield in wheat and barley crops, based on results achieved by the authors of the present work. The number of grains per m2 was the main numerical component that explained grain yield variations, independently of the species and the nature of the stress. The number of grains per m2 is defined around anthesis, and the use of simulation models is a tool to evaluate when anthesis date will occur.Fil: Abeledo, Leonor Gabriela. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Cerealicultura; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Serrago, Roman Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Cerealicultura; ArgentinaFil: de San Celedonio, Romina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Producción Vegetal; ArgentinaFil: Lo Valvo, Patricio Javier. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Producción Vegetal; ArgentinaFil: Miralles, Daniel Julio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Cerealicultura; Argentin

    Synchronization of non-chaotic dynamical systems

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    A synchronization mechanism driven by annealed noise is studied for two replicas of a coupled-map lattice which exhibits stable chaos (SC), i.e. irregular behavior despite a negative Lyapunov spectrum. We show that the observed synchronization transition, on changing the strength of the stochastic coupling between replicas, belongs to the directed percolation universality class. This result is consistent with the behavior of chaotic deterministic cellular automata (DCA), supporting the equivalence Ansatz between SC models and DCA. The coupling threshold above which the two system replicas synchronize is strictly related to the propagation velocity of perturbations in the system.Comment: 16 pages + 12 figures, new and extended versio

    Performance in Transverse Direction of Fiber‐Reinforced Polymer Bridge Decks

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    Pultruded glass fiber‐reinforced polymer (GFRP) bridge decks distribute punctual vehicular loads to the underlying superstructure and can also act as the upper chord of hybrid main girders. The deck’s structural performance in both cases is influenced by its transverse behavior. The static bending behavior in the transverse‐to‐pultrusion direction of two GFRP bridge deck systems with trapezoidal (DS) and triangular (AS) cell cross‐sectional geometry was experimentally studied. Different load transfer mechanisms were found in DS (frame‐dominated) and AS (truss‐governed) depending on the cell geometry. The DS deck exhibited a lower apparent bending stiffness and degree of composite action between the face sheets than the AS deck, which was attributed to the lower transverse in‐plane shear stiffness provided by the trapezoidal core than by the triangular core. The system in‐plane shear moduli were estimated from the experimental deflection results

    Measuring the Burden of Hospitalization in Patients with Parkinson´s Disease in Spain

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    Introduction: This epidemiological survey estimates the hospitalization burden related to Parkinson´s Disease in Spain. Methods: This observational retrospective survey was performed by reviewing data from the National Surveillance System for Hospital Data, which includes more than 98% of Spanish hospitals. All hospitalizations of patients with Parkinson´s disease that were reported from 1997-2012 were analyzed. Codes were selected using the 9th International Classification of Diseases: ICD-9-CM: 332.0. Results: A total of 438,513 hospital discharges of patients with Parkinson´s Disease were reported during the study period. The annual hospitalization rate was 64.2 cases per 100,000. The average length of hospital stay was 10 days. The trend for the annual hospitalization rate differed significantly depending on whether Parkinson´s disease was the main cause of hospitalization (n = 23,086, 1.14% annual increase) or was not the main cause of hospitalization (n = 415,427, 15.37% annual increase). The overall case-fatality rate among hospitalized patients was 10%. The case fatality rate among patient´s hospitalized with Parkinson´s disease as the main cause of hospitalization was 2.5%. The hospitalization rate and case-fatality rate significantly increased with age. The primary causes of hospitalization when Parkinson´s disease was not coded as the main cause of hospitalization were as follows: respiratory system diseases (24%), circulatory system diseases (19%), injuries and poisoning, including fractures (12%), diseases of the digestive system (10%) and neoplasms (5%). The annual average cost for National Health Care System was € 120 M, with a mean hospitalization cost of €4,378. Conclusions: Parkinson´s disease poses a significant health threat in Spain, particularly in the elderly. While hospitalizations due to Parkinson´s Disease are relatively stable over time, the number of patients presenting with Parkinson´s disease as an important comorbidity has increased dramatically. Medical staff must be specifically trained to treat the particular needs of hospitalized patients suffering from Parkinson´s disease as an important comorbidity.Funding sources for study: The cathedra “Evaluación de Resultados en Salud. Rey Juan Carlos University” is sponsored by Abbvie.S

    The Visible Hand of corporate entrepreneurship in state-owned enterprises:A longitudinal study of the Spanish national postal operator

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    This study explores how the corporate entrepreneurship (CE) of state-owned enterprises (SOEs) evolves under varying conditions of state ownership and control, laws and norms, and competence in the market. For this purpose, we present a longitudinal case study focused on the Spanish postal operator Correos using qualitative archival data and interviews. Our results indicate that the willingness and capacity of an SOE to act entrepreneurially depends critically on its degree of autonomy from the state and on the extent to which its legal and market environments increase its dynamism, complexity, and hostility. We also show that the development of CE in an SOE may lead to improved service quality, operational efficiency, and business specialization; facilitate its market positioning; and foster its sustainability through the exploration and exploitation of strategic alliances that can increase its business scope

    Age and mass studies for young star clusters in M31 from SEDs-fit

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    In this paper, we present photometry for young star clusters in M31, which are selected from Caldwell et al. These star clusters have been observed as part of the Beijing--Arizona--Taiwan--Connecticut (BATC) Multicolor Sky Survey from 1995 February to 2008 March. The BATC images including these star clusters are taken with 15 intermediate-band filters covering 3000--10000 \AA. Combined with photometry in the {\sl GALEX} far- and near-ultraviolet, broad-band UBVRIUBVRI, SDSS ugrizugriz, and infrared JHKsJHK_{\rm s} of Two Micron All Sky Survey, we obtain their accurate spectral energy distributions (SEDs) from 1538-20000 \AA. We derive these star clusters' ages and masses by comparing their SEDs with stellar population synthesis models. Our results are in good agreement with previous determinations. The mean value of age and mass of young clusters (<2<2 Gyr) is about 385 Myr and 2×104M2\times 10^4 {M_\odot}, respectively. There are two distinct peaks in the age distribution, a highest peak at age \sim 60 Myr and a secondary peak around 250 Myr, while the mass distribution shows a single peak around 104M10^4 {M_\odot}. A few young star clusters have two-body relaxation times greater than their ages, indicating that those clusters have not been well dynamically relaxed and therefore have not established the thermal equilibrium. There are several regions showing aggregations of young star clusters around the 10 kpc ring and the outer ring, indicating that the distribution of the young star clusters is well correlated with M31's star-forming regions. The young massive star clusters (age 100\leq 100 Myr and mass 104M\geq 10^4 {M_\odot}) show apparent concentration around the ring splitting region, suggesting a recent passage of a satellite galaxy (M32) through M31 disk.Comment: Accepted for Publication in AJ, 15 pages, 14 figures and 4 table

    3D Virtual modelling, 3D printing and extended reality for planning of implant procedure of short-term and long-term mechanical circulatory support devices and heart transplantation

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    IntroductionThe use of three-dimensional (3D) reconstruction and printing technology, together with extended reality applied to advanced heart failure adult patients with complex anatomy, is rapidly spreading in clinical practice. We report practical experience with application to acute and chronic heart failure: planning and performing mechanical circulatory device insertion or heart transplantation.MethodsFrom November 2019 until February 2022, 53 3D virtual biomodels were produced for intervention planning (using Virtual/Augmented Reality and/or 3D printing), following a specific segmentation and preprocessing workflow for biomodelling, in patients with advanced heart failure due to structural heart disease or cardiomyopathies. Four of those patients were complex cases requiring mechanical circulatory support implant procedures in our center.ResultsOne short-term and three long-term ventricular assist device system were successfully clinically implanted after application of this technique. In other two cases with extremely high procedural risk, visualized after application of this multimodality imaging, heart transplantation was elected.Conclusion3D printing based planning and virtual procedure simulation, are of great importance to select appropriate candidates for mechanical circulatory support in case of complex patient anatomy and may help to diminish periprocedural complications. Extended reality represents a perspective tool in planification of complex surgical procedures or ventricular assist device insertion in this setting
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