133 research outputs found
An Analytic Method for S-Expansion involving Resonance and Reduction
In this work we describe an analytic method able to give the multiplication table(s) of the set(s) involved in an S-expansion process (with either resonance or 0-resonant-reduction) for reaching a target Lie (super)algebra from a starting one,after having properly chosen the partitions over subspaces of the considered (super)algebras. This analytic method gives us a simple set of expressions to find the subset decomposition of the set(s) involved in the process. Then, we use the information coming from both the initial (super)algebra and the target one for reaching the multiplication table(s) of the mentioned set(s). We also give some interesting examples of application which check and corroborate our analytic procedure andgeneralize some result already presented in the literatur
Chitosan-g-oligo(epsilon-caprolactone) polymeric micelles: microwave-assisted synthesis and physicochemical and cytocompatibility characterization
With the aim to produce mucoadhesive polymeric micelles for drug administration by mucosal routes, chitosan-g-oligo(epsilon-caprolactone) copolymers were synthesized by the microwave-assisted ring-opening polymerization of epsilon-caprolactone using chitosan as the macroinitiator and methanesulfonic acid as the solvent, catalyst and protecting group of the amine moieties. The reaction was conducted under very mild conditions and was completed within 10 min with a monomer conversion above 90%. The grafting of oligo(epsilon-caprolactone) blocks to the free hydroxyl groups of chitosan was confirmed by ATR/FT-IR, 1H- and 13C-NMR, WAXD and thermal analysis (TGA/DSC). The molecular weight of the synthetic hybrid copolymers was determined by GPC and MALDI-ToF mass spectrometry. Polymeric micelles obtained by the solvent diffusion/evaporation method showed a spherical shape (TEM and AFM) with sizes between 111 and 154 nm and highly positive zeta potential (>+50 mV) (DLS). In addition, they displayed good cell compatibility in the human lung adenocarcinoma epithelial line, A549, and were readily up-taken by the cervical cancer cell line, HeLa. Results from the encapsulation of the antituberculosis drug, rifampicin, showed that the micelles had better performance than other nanocarriers previously investigated (e.g., cyclodextrins). Moreover, the micelles conserved the mucoadhesiveness displayed by pristine chitosan and are expected to transiently open tight cell junctions and lead to more prolonged residence times in mucosal tissues and greater drug bioavailability.Fil: Glisoni, Romina Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Nanobiotecnología. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología; ArgentinaFil: Quintana Lazópulos, Silvina Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; ArgentinaFil: Molina, María. Freie Universität Berlin; AlemaniaFil: Calderon, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Freie Universität Berlin; AlemaniaFil: Moglioni, Albertina Gladys. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; ArgentinaFil: Sosnik, Alejandro Dario. Technion - Israel Institute of Technology; Israel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
An Intelligent Transportation System: the Quito City Case Study
Managing traffic in a large city has become a topic of great interest in both politics and science. The costs of poor traffic management have been quantified as losses equal to millions of dollars, not counting the unquantifiable value of the time that a person loses in traffic jams. Intelligent transport systems (ITS) offer a set of innovative solutions specific to the management of different modes of transport. This article focuses on the development of an ITS for the city of Quito that allows smart decision-making to direct heavy haul transporters that want to enter the city via one of its main access routes. Technologies such as Sensor Web Enablement (SWE), in association with the Message Queuing Telemetry Transport (MQTT) communication protocol, facilitate the development of a vehicular management platform/system capable of sending notifications in real-time and issuing instructions to drivers regarding traffic delays along routes, average speeds, etc. The system supports a network of heterogeneous sensors accessible through the web. It can integrate any device that uses HTTP protocol. Time interval and location range testing have been undertaken to refine the accuracy of the system and make it adaptable to any geographic situation. The system allows communicate with the server through MQTT or through web services, using technologies such as: MongoDB and GeoJSON. One of the most relevant results is that the degree of accuracy of the system is within appropriate ranges when compared to commercial applications such as Google Maps and Waze
Synthesis and magnetic properties of cobalt-iron/cobalt-ferrite soft/hard magnetic core/shell nanowires
A straightforward method for the synthesis of CoFe2.7/CoFe2O4 core/shell nanowires is described. The proposed method starts with a conventional pulsed electrodeposition procedure on alumina nanoporous template. The obtained CoFe2.7 nanowires are released from the template and allowed to oxidize at room conditions over several weeks. The effects of partial oxidation on the structural and magnetic properties were studied by x-ray spectrometry, magnetometry, and scanning and transmission electron microscopy. The results indicate that the final nanowires are composed of 5 nm iron-cobalt alloy nanoparticles. Releasing the nanowires at room conditions promoted surface oxidation of the nanoparticles and created a CoFe2O4 shell spinel-like structure. The shell avoids internal oxidation and promotes the formation of bi-magnetic soft/hard magnetic core/shell nanowires. The magnetic properties of both the initial single-phase CoFe2.7 nanowires and the final core/shell nanowires, reveal that the changes in the properties from the array are due to the oxidation more than effects associated with released processes (disorder and agglomeration).Fil: Londoño Calderon, Cesar Leandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; ArgentinaFil: Moscoso Londoño, Oscar. Universidade Estadual de Campinas; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Muraca, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidade Estadual de Campinas; Brasil. Brazilian Center for Research in Energy and Materials. Brazilian Nanotechnology National Laboratory; BrasilFil: Arzuza, Luis. Universidade Estadual de Campinas; BrasilFil: Carvalho, Peterson. Universidade Estadual de Campinas; BrasilFil: Pirota, Kleber Roberto. Universidade Estadual de Campinas; BrasilFil: Knobel, Marcelo. Universidade Estadual de Campinas; BrasilFil: Pampillo, Laura Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; ArgentinaFil: Martinez Garcia, Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Formosa. Facultad de Recursos Naturales; Argentin
Crosslinked casein-based micelles as a dually responsive drug delivery system
New types of biodegradable nanocarriers for drug delivery were prepared using casein (CAS) micelles as particle templates and glyceraldehyde (GAL) as a crosslinking agent. We found that highly crosslinked casein micelles (CCM) maintained their structural integrity at pH 7.4 (plasma conditions) but were easily degraded in the presence of proteases at pH 5 (lysosomal conditions). Nile red (NR) was chosen as a hydrophobic model drug inspired by the natural role of casein as lipophilic nutrient nanotransporter. The cumulative release of the NR-loaded micelles showed marginal dye leakage at pH 7.4 but was significantly accelerated by protease and pH-mediated degradation of the nanocarriers in a dual-responsive fashion. The prepared nanocarriers possess many favorable features for drug delivery: excellent biocompatibility and biodegradability, high stability in physiological conditions, remarkable capacity for the encapsulation of hydrophobic drugs, minimal drug leakage under extracellular conditions, and rapid drug release in response to the endo-lysosomal levels of pH and proteases. In this regard, the prepared CCM represent a promising candidate for the delivery and triggered release of anti-cancer drugs in lysosomal environments.Fil: Picchio, Matías Luis. Universidad Nacional de Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada; ArgentinaFil: Cuggino, Julio César. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Nagel, Gregor. Freie Universitat Berlin; AlemaniaFil: Wedepohl, Stefanie. Freie Universitat Berlin; AlemaniaFil: Minari, Roque Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Alvarez Igarzabal, Cecilia Ines. Universidad Nacional de Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada; Argentina. Freie Universitat Berlin; AlemaniaFil: Gugliotta, Luis Marcelino. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Calderon, Marcelo. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; Argentina. Freie Universitat Berlin; Alemani
Development of caprine preantral follicles after orthotopic autotransplantation of ovarian tissue
Objective: The aim of this study was to evaluate the follicle morphology, density, development and hormone production after orthotopic autransplantation of fresh or vitrified goat ovarian tissue. Methods: Fresh and vitrified ovarian cortex was orthotopically autotransplanted for six months in two and three adults bilaterally ovariectomized goats, respectively. The animals were monitored during 196 days and blood samples collected. Results: It was observed that the percentage of morphologically normal preantral follicles (MNPF) after grafting of fresh ovarian tissue was similar to control. The follicular density in the fresh graft reduced significantly when compared to fresh control. unfortunately, after transplantation of vitrified tissue it was not possible to identified any follicles after recovery. Furthermore, the proportion of developing follicles was higher (P < 0.05) in the fresh auto-grafts than in control fragments. Moreover, progesterone plasma levels increased significantly from day 179 to day 195 of transplantation. Conclusion: In conclusion, orthotopic transplantation of fresh ovarian tissue was able to keep healthy the preantral follicles, as well as the restoration of goat endocrine function
Longitudinal Spin Transfer to and Hyperons in Polarized Proton-Proton Collisions at = 200 GeV
The longitudinal spin transfer, , from high energy polarized protons
to and hyperons has been measured for the first time
in proton-proton collisions at with the STAR
detector at RHIC. The measurements cover pseudorapidity, , in the range
and transverse momenta, , up to . The longitudinal spin transfer is found to be for inclusive
and for
inclusive hyperons with and . The dependence on and is presented.Comment: 5 pages, 4 figure
Strangeness Enhancement in Cu+Cu and Au+Au Collisions at \sqrt{s_{NN}} = 200 GeV
We report new STAR measurements of mid-rapidity yields for the ,
, , , , ,
particles in Cu+Cu collisions at \sNN{200}, and mid-rapidity
yields for the , , particles in Au+Au at
\sNN{200}. We show that at a given number of participating nucleons, the
production of strange hadrons is higher in Cu+Cu collisions than in Au+Au
collisions at the same center-of-mass energy. We find that aspects of the
enhancement factors for all particles can be described by a parameterization
based on the fraction of participants that undergo multiple collisions
Observation of the antimatter helium-4 nucleus
High-energy nuclear collisions create an energy density similar to that of
the universe microseconds after the Big Bang, and in both cases, matter and
antimatter are formed with comparable abundance. However, the relatively
short-lived expansion in nuclear collisions allows antimatter to decouple
quickly from matter, and avoid annihilation. Thus, a high energy accelerator of
heavy nuclei is an efficient means of producing and studying antimatter. The
antimatter helium-4 nucleus (), also known as the anti-{\alpha}
(), consists of two antiprotons and two antineutrons (baryon
number B=-4). It has not been observed previously, although the {\alpha}
particle was identified a century ago by Rutherford and is present in cosmic
radiation at the 10% level. Antimatter nuclei with B < -1 have been observed
only as rare products of interactions at particle accelerators, where the rate
of antinucleus production in high-energy collisions decreases by about 1000
with each additional antinucleon. We present the observation of the antimatter
helium-4 nucleus, the heaviest observed antinucleus. In total 18
counts were detected at the STAR experiment at RHIC in 10 recorded Au+Au
collisions at center-of-mass energies of 200 GeV and 62 GeV per nucleon-nucleon
pair. The yield is consistent with expectations from thermodynamic and
coalescent nucleosynthesis models, which has implications beyond nuclear
physics.Comment: 19 pages, 4 figures. Submitted to Nature. Under media embarg
Inclusive charged hadron elliptic flow in Au + Au collisions at = 7.7 - 39 GeV
A systematic study is presented for centrality, transverse momentum ()
and pseudorapidity () dependence of the inclusive charged hadron elliptic
flow () at midrapidity() in Au+Au collisions at
= 7.7, 11.5, 19.6, 27 and 39 GeV. The results obtained with
different methods, including correlations with the event plane reconstructed in
a region separated by a large pseudorapidity gap and 4-particle cumulants
(), are presented in order to investigate non-flow correlations and
fluctuations. We observe that the difference between and
is smaller at the lower collision energies. Values of , scaled by
the initial coordinate space eccentricity, , as a function
of are larger in more central collisions, suggesting stronger collective
flow develops in more central collisions, similar to the results at higher
collision energies. These results are compared to measurements at higher
energies at the Relativistic Heavy Ion Collider ( = 62.4 and 200
GeV) and at the Large Hadron Collider (Pb + Pb collisions at =
2.76 TeV). The values for fixed rise with increasing collision
energy within the range studied (). A comparison to
viscous hydrodynamic simulations is made to potentially help understand the
energy dependence of . We also compare the results to UrQMD
and AMPT transport model calculations, and physics implications on the
dominance of partonic versus hadronic phases in the system created at Beam
Energy Scan (BES) energies are discussed.Comment: 20 pages, 12 figures. Version accepted by PR
- …