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González-Rodríguez J, Conde JJ, Vargas-Osorio Z, Vázquez-Vázquez C, Piñeiro Y, Rivas J, Feijoo G, Moreira MT. LED-driven photo-Fenton process for micropollutant removal by nanostructured magnetite anchored in mesoporous silica. J Environ Manage 2024; 349:119461. [PMID: 37922820 DOI: 10.1016/j.jenvman.2023.119461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 10/20/2023] [Accepted: 10/21/2023] [Indexed: 11/07/2023]
Abstract
The presence of organic micropollutants in water bodies represents a threat to living organisms and ecosystems due to their toxicological effects and recalcitrance in conventional wastewater treatments. In this context, the application of heterogeneous photo-Fenton based on magnetite nanoparticles supported on mesoporous silica (SBA15) is proposed to carry out the non-specific degradation of the model compounds ibuprofen, carbamazepine, hormones, bisphenol A and the dye ProcionRed®. The operating conditions (i.e., pH, catalyst load and hydrogen peroxide concentration) were optimized by Response Surface Methodology (RSM). The paramagnetic properties of the nanocatalysts allowed their repeated use in sequential batch operations with catalyst losses below 1%. The feasibility of the process was demonstrated as removal rates above 90% after twelve accomplished after twelve consecutive cycles. In addition, the contributions of different reactive oxygen species, mainly •OH, were analyzed together with the formation of by-products, achieving total mineralization values of 15% on average.
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Affiliation(s)
- J González-Rodríguez
- CRETUS, Department of Chemical Engineering, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain.
| | - J J Conde
- CRETUS, Department of Chemical Engineering, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - Z Vargas-Osorio
- Department of Biomaterials, Centre for Functional and Surface Functionalized Glass (FUNGLASS), Alexander Dubcek University of Trencin, Slovakia; Laboratory of Magnetism and Nanotechnology, Department of Physical Chemistry, Faculty of Chemistry, and Applied Physics, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - C Vázquez-Vázquez
- Laboratory of Magnetism and Nanotechnology, Department of Physical Chemistry, Faculty of Chemistry, and Applied Physics, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - Y Piñeiro
- Laboratory of Magnetism and Nanotechnology, Department of Physical Chemistry, Faculty of Chemistry, and Applied Physics, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - J Rivas
- Laboratory of Magnetism and Nanotechnology, Department of Physical Chemistry, Faculty of Chemistry, and Applied Physics, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - G Feijoo
- CRETUS, Department of Chemical Engineering, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - M T Moreira
- CRETUS, Department of Chemical Engineering, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
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Maglio M, Sartori M, Gambardella A, Shelyakova T, Dediu VA, Santin M, Piñeiro Y, López MB, Rivas J, Tampieri A, Sprio S, Martini L, Gatti A, Russo A, Giavaresi G, Fini M. Bone Regeneration Guided by a Magnetized Scaffold in an Ovine Defect Model. Int J Mol Sci 2023; 24:ijms24010747. [PMID: 36614190 PMCID: PMC9821288 DOI: 10.3390/ijms24010747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 12/26/2022] [Accepted: 12/28/2022] [Indexed: 01/04/2023] Open
Abstract
The reconstruction of large segmental defects still represents a critical issue in the orthopedic field. The use of functionalized scaffolds able to create a magnetic environment is a fascinating option to guide the onset of regenerative processes. In the present study, a porous hydroxyapatite scaffold, incorporating superparamagnetic Fe3O4 nanoparticles (MNPs), was implanted in a critical bone defect realized in sheep metatarsus. Superparamagnetic nanoparticles functionalized with hyperbranched poly(epsilon-Lysine) peptides and physically complexed with vascular endothelial growth factor (VEGF) where injected in situ to penetrate the magnetic scaffold. The scaffold was fixed with cylindrical permanent NdFeB magnets implanted proximally, and the magnetic forces generated by the magnets enabled the capture of the injected nanoparticles forming a VEGF gradient in its porosity. After 16 weeks, histomorphometric measurements were performed to quantify bone growth and bone-to-implant contact, while the mechanical properties of regenerated bone via an atomic force microscopy (AFM) analysis were investigated. The results showed increased bone regeneration at the magnetized interface; this regeneration was higher in the VEGF-MNP-treated group, while the nanomechanical behavior of the tissue was similar to the pattern of the magnetic field distribution. This new approach provides insights into the ability of magnetic technologies to stimulate bone formation, improving bone/scaffold interaction.
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Affiliation(s)
- Melania Maglio
- Surgical Sciences and Technologies, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
| | - Maria Sartori
- Surgical Sciences and Technologies, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
- Correspondence: ; Tel.: +39-05-1636-6787
| | - Alessandro Gambardella
- Surgical Sciences and Technologies, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
| | - Tatiana Shelyakova
- Surgical Sciences and Technologies, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
| | - Valentin Alek Dediu
- Istituto per lo Studio dei Materiali Nanostrutturati, Consiglio Nazionale delle Ricerche, 40129 Bologna, Italy
| | - Matteo Santin
- Centre for Regenerative Medicine and Devices, School of Applied Sciences, University of Brighton Huxley Building Lewes Road, Brighton BN2 4GJ, UK
| | - Yolanda Piñeiro
- Department of Applied Physics, University of Santiago de Compostela, E15782 Santiago de Compostela, Spain
| | | | - Josè Rivas
- Department of Applied Physics, University of Santiago de Compostela, E15782 Santiago de Compostela, Spain
| | - Anna Tampieri
- Institute of Science, Technology and Sustainability for Ceramics-National Research Council (ISSMC-CNR, Former ISTEC), 48018 Faenza, Italy
| | - Simone Sprio
- Institute of Science, Technology and Sustainability for Ceramics-National Research Council (ISSMC-CNR, Former ISTEC), 48018 Faenza, Italy
| | - Lucia Martini
- Surgical Sciences and Technologies, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
| | - Alessandro Gatti
- II Clinic of Orthopaedics and Traumatology, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
| | - Alessandro Russo
- II Clinic of Orthopaedics and Traumatology, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
| | - Gianluca Giavaresi
- Surgical Sciences and Technologies, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
| | - Milena Fini
- Surgical Sciences and Technologies, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
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Teijeiro-Valiño C, González Gómez MA, Yáñez S, García Acevedo P, Arnosa Prieto A, Belderbos S, Gsell W, Himmelreich U, Piñeiro Y, Rivas J. Biocompatible magnetic gelatin nanoparticles with enhanced MRI contrast performance prepared by single-step desolvation method. Nano Ex 2021. [DOI: 10.1088/2632-959x/abf58e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Abstract
Magnetic nanoparticles are versatile materials that have boosted the development of different biomedical applications, being superparamagnetic magnetite nanoparticles a milestone in the field, after achieving clinical approval as contrast agents in magnetic resonance imaging (Feridex®), magnetic hyperthermia agents for oncological treatments (NanoTherm®), or iron deficiency supplement (Feraheme®). However, its potential as theragnostic agent could be further expanded by its encapsulation within a biodegradable hydrogel, capable of enhancing the biocompatibility and loading abilities, to simultaneously carry drugs, radiotracers, or biomolecules. Gelatin, is a natural biopolymer with optimal in vivo feature and gelling capacity that has been extensively used for decades in pharmaceuticals. In this work, we have addressed the preparation of gelatin nanoparticles, bare and loaded with magnetite nanoparticles, with controlled size to be used as contrast agents in magnetic resonance imaging. The main formulation parameters influencing the preparation of gelatin nanoparticles with controlled size by single-step desolvation method, were studied and optimized, to produce small gelatin nanoparticles (97nm) and highly loaded (38% w/w) Fe3O4@citrate gelatin nanoparticles (150 nm) with high magnetic response (65emus/g). The viability assays of the magnetic gelatin nanoparticles, tested with mesenchymal stem cells, showed negligible toxicity and in vitro magnetic resonance imaging tests, performed in agar phantoms, revealed a good contrast for T2 weighting MRI, r2 = 265.5(mM−1 s−1), superior to commercial products, such as Resovist or Endorem.
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Zegarra A, Rivas J, Gallegos A, Mellisho E. 53 Effect of anthocyanin supplementation in bovine pre-implantation embryonic development during invitro maturation of oocytes. Reprod Fertil Dev 2021. [DOI: 10.1071/rdv33n2ab53] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Oocyte protection against reactive oxygen species (ROS) during invitro maturation (IVM) may play a decisive role in pre-implantation embryonic development. For instance, anthocyanins have shown greater antioxidant effects than vitamins C and E. The objective of this study was to determine the anthocyanin supplementation level that influences quantity and quality of bovine blastocysts development during IVM. Cumulus–oocyte complexes (COC) were recovered from 185 abattoir ovaries in 6 sessions and classified (Grade 1 and 2) for maturation. Oocytes were in IVM in commercial medium (Vitrogen®) supplemented with anthocyanin (pelargonidin chloride) at different concentrations: 0 (control), 1, 10, 20, and 40μM, in droplets of 70μL with 12 to 15 COC at 38.5°C, 5% CO2 and 90% humidity for 22to 24h. Sperm selection was performed by Percoll gradient method (45/90%) with centrifugation at 600×g for 6min. The final concentration for IVF was 2×106 sperm mL−1. A total of 462 oocytes were used in the experiment (6 replicates). Presumptive zygotes were invitro cultured (IVC) in commercial medium (Vitrogen) in droplets of 70µL with 12–15 zygotes at 38°C, 5% CO2, and 90% humidity until the blastocyst stage (Day 7 of culture). The cleavage (Day 2), morulae (Day 4), and blastocyst (Day 7) rates were measured during IVC. The data were processed with non-parametric tests (Kruskal–Wallis test with independent samples, P<0.05) using IBM SPSS Statistics 2.0 for Windows. The results in the control group of cleavage, morulae, and blastocyst rates were 67.3, 27.0, and 22.1%, respectively. Although, numerically, anthocyanin at 1μM resulted in a higher blastocyst rate (28.8%) and anthocyanin at 10μM resulted in a greater number of blastocysts of advanced stages (65.0%), anthocyanin supplementation during IVM did not influence the quantity and quality of bovine blastocyst development (P>0.05). In conclusion, the supplementation of anthocyanin to the maturation medium did not affect invitro development of bovine embryos. Complementary studies at the cellular and gene expression level may be required.
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Vega J, Rodriguez M, Dipaz-Berrocal D, Rivas J, Huayhua C, Mellisho E. 61 Swim-up and microfluidic techniques improve the kinetic parameters of selected bovine spermatozoa for invitro fertilization: Preliminary results. Reprod Fertil Dev 2021. [DOI: 10.1071/rdv33n2ab61] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
For invitro embryo production, spermatozoa with fertilizing capacity must possess optimal kinetic, morphometric, vitality, and DNA integrity characteristics. The objective of this study was to evaluate the effect of 3 sperm selection methods on sperm quality and invitro embryonic development in bovine. Frozen commercial semen (0.5 mL/straws) from one bull with known fertility was thawed at 37°C for 20s and was divided for 3 sperm selection techniques: density gradient, swim-up, and microfluidic sperm sorting. The sperm kinetic parameters (VCL=curvilinear velocity, VSL=straight line velocity, VAP=average path velocity, ALH=lateral displacement of sperm head, BCF=beat frequency cross, STR=path straightness) were assessed using computer-assisted sperm analysis (CASA). Sperm morphometric parameters were evaluated using Diff-Quick staining followed by automated analysis. To assess vitality, the sperm were stained with propidium iodide and acridine orange, then analysed under a fluorescence microscope. In addition, DNA fragmentation was assessed using sperm chromatin dispersion method. Last, the fertilizing capacity of the selected sperm was tested by fertilizing cumulus–oocyte complexes (2×106 sperm mL−1) obtained from slaughterhouse ovaries and matured invitro for 24h. A standardized invitro embryo production protocol was used with commercial medium from Vitrogen. The cleavage rate and blastocyst yield were measured on Day 2 and 7, respectively (fertilization=Day 0). The results were calculated with analysis of variance and Tukey’s test (P<0.05). The values of sperm kinetic parameters obtained with swim-up (VCL 132.5µm/s; VSL 73.5µm/s) and microfluidic technique (VCL 129.5µm/s; VSL 64.4µm/s) were significantly higher (P<0.05) than those obtained by density gradient (VCL 98.3µm/s; VSL 45.01µm/s). However, the total and progressive motility by density gradient method was slightly higher (89% and 57%) compared with that assessed by swim-up (64% and 43%) or microfluidic technique (74% and 54%) respectively. Microfluidic sorting (11.3%) showed lower (P<0.05) DNA fragmentation levels compared with density gradient method (16.6%), whereas the swim-up technique (12.5%) was similar between both groups. No significant difference was detected between the 3 groups for sperm morphometric and vitality parameters. Moreover, cleavage rates were similar (P>0.05) between the 3 sperm selection techniques: density gradient (84.0%), swim-up (75.2%), and microfluidic sorting (67.3%). However, blastocyst yield was significantly higher (P<0.05) using sperm selected by density gradient (28.1%) and swim-up (21.9%) compared with microfluidic sorting (15.3%). In conclusion, sperm selection using microfluidic and swim-up techniques improved kinetic parameters with lower levels of DNA fragmentation, without affecting sperm morphometry. However, both the density gradient and swim-up techniques are efficient systems for producing invitro bovine embryo.
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Fernández L, González-Rodríguez J, Gamallo M, Vargas-Osorio Z, Vázquez-Vázquez C, Piñeiro Y, Rivas J, Feijoo G, Moreira MT. Iron oxide-mediated photo-Fenton catalysis in the inactivation of enteric bacteria present in wastewater effluents at neutral pH. Environ Pollut 2020; 266:115181. [PMID: 32683092 DOI: 10.1016/j.envpol.2020.115181] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/03/2020] [Accepted: 07/03/2020] [Indexed: 06/11/2023]
Abstract
The pressure on natural water resources associated with increasing water scarcity highlights the value of using reclaimed water through the development of efficient and environmentally friendly treatment technologies. In this work, the use of magnetic nanoparticles in photo-Fenton catalysis for water disinfection was considered to inactivate natural enteric bacteria present in municipal wastewater effluents under white light and neutral pH. The most recommended ranges were evaluated in key variables such as the loading and composition of nanoparticles (NPs), hydrogen peroxide (H2O2) concentration, the light source (UV and visible) and treatment time were evaluated in wastewater disinfection expressed in terms of total coliforms and Escherichia coli colony forming units (CFU). The magnetic separation of NPs allowed the disinfection process to be carried out in different cycles, facilitating the recovery of the nanocatalyst and avoiding its discharge with the treated effluent.
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Affiliation(s)
- L Fernández
- CRETUS Institute, Department of Chemical Engineering, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - J González-Rodríguez
- CRETUS Institute, Department of Chemical Engineering, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain.
| | - M Gamallo
- CRETUS Institute, Department of Chemical Engineering, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - Z Vargas-Osorio
- Laboratory of Magnetism and Nanotechnology, Departments of Physical Chemistry, Faculty of Chemistry, and Applied Physics, Faculty of Physics, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain; Department of Biomaterials, Centre for Functional and Surface Functionalized Glass (FUNGLASS), Alexander Dubcek University of Trencin, Slovakia
| | - C Vázquez-Vázquez
- Laboratory of Magnetism and Nanotechnology, Departments of Physical Chemistry, Faculty of Chemistry, and Applied Physics, Faculty of Physics, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - Y Piñeiro
- Laboratory of Magnetism and Nanotechnology, Departments of Physical Chemistry, Faculty of Chemistry, and Applied Physics, Faculty of Physics, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - J Rivas
- Laboratory of Magnetism and Nanotechnology, Departments of Physical Chemistry, Faculty of Chemistry, and Applied Physics, Faculty of Physics, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - G Feijoo
- CRETUS Institute, Department of Chemical Engineering, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - M T Moreira
- CRETUS Institute, Department of Chemical Engineering, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
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González-Jartín JM, de Castro Alves L, Alfonso A, Piñeiro Y, Vilar SY, Rodríguez I, Gomez MG, Osorio ZV, Sainz MJ, Vieytes MR, Rivas J, Botana LM. Magnetic nanostructures for marine and freshwater toxins removal. Chemosphere 2020; 256:127019. [PMID: 32417588 DOI: 10.1016/j.chemosphere.2020.127019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 04/21/2020] [Accepted: 05/07/2020] [Indexed: 06/11/2023]
Abstract
Marine and freshwater toxins contaminate water resources, shellfish and aquaculture products, causing a broad range of toxic effects in humans and animals. Different core-shell nanoparticles were tested as a new sorbent for removing marine and freshwater toxins from liquid media. Water solutions were contaminated with 20 μg/L of marine toxins and up to 50 μg/L of freshwater toxins and subsequently treated with 250 or 125 mg/L of nanoparticles. Under these conditions, carbon nanoparticles removed around 70% of saxitoxins, spirolides, and azaspiracids, and up to 38% of diarrheic shellfish poisoning toxins. In the case of freshwater toxins, the 85% of microcystin LR was eliminated; other cyclic peptide toxins were also removed in a high percentage. Marine toxins were adsorbed in the first 5 min of contact, while for freshwater toxins it was necessary 60 min to reach the maximum adsorption. Toxins were recovered by extraction from nanoparticles with different solvents. Gymnodinium catenatum, Prorocentrum lima, and Microcystis aeruginosa cultures were employed to test the ability of nanoparticles to adsorb toxins in a real environment, and the same efficacy to remove toxins was observed in these conditions. These results suggest the possibility of using the nanotechnology in the treatment of contaminated water or in chemical analysis applications.
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Affiliation(s)
- Jesús M González-Jartín
- Departamento de Farmacología, Facultad de Veterinaria, Universidade de Santiago de Compostela, 27002, Lugo, Spain.
| | - Lisandra de Castro Alves
- Departamento de Física Aplicada, Universidad de Santiago de Compostela, Facultad de Física, 15782, Santiago de Compostela, Spain.
| | - Amparo Alfonso
- Departamento de Farmacología, Facultad de Veterinaria, Universidade de Santiago de Compostela, 27002, Lugo, Spain.
| | - Y Piñeiro
- Departamento de Física Aplicada, Universidad de Santiago de Compostela, Facultad de Física, 15782, Santiago de Compostela, Spain.
| | - Susana Yáñez Vilar
- Departamento de Física Aplicada, Universidad de Santiago de Compostela, Facultad de Física, 15782, Santiago de Compostela, Spain.
| | - Inés Rodríguez
- Departamento de Farmacología, Facultad de Veterinaria, Universidade de Santiago de Compostela, 27002, Lugo, Spain; Laboratario CIFGA S.A., Avda. Benigno Rivera, 56, 27003, Lugo, Spain.
| | - Manuel González Gomez
- Departamento de Física Aplicada, Universidad de Santiago de Compostela, Facultad de Física, 15782, Santiago de Compostela, Spain.
| | - Zulema Vargas Osorio
- Departamento de Física Aplicada, Universidad de Santiago de Compostela, Facultad de Física, 15782, Santiago de Compostela, Spain.
| | - María J Sainz
- Departamento de Producción Vegetal y Proyectos de Ingeniería, Facultad de Veterinaria, Universidade de Santiago de Compostela, 27002, Lugo, Spain.
| | - Mercedes R Vieytes
- Departamento de Fisiología, Facultad de Veterinaria, Universidade de Santiago de Compostela, 27002, Lugo, Spain.
| | - J Rivas
- Departamento de Física Aplicada, Universidad de Santiago de Compostela, Facultad de Física, 15782, Santiago de Compostela, Spain.
| | - Luis M Botana
- Departamento de Farmacología, Facultad de Veterinaria, Universidade de Santiago de Compostela, 27002, Lugo, Spain.
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Morantes M, Dios-Palomares R, Urdaneta F, Rivas J, García-Martínez A. Eficiencia técnica en sistemas de producción con bovinos de doble propósito. ARCH ZOOTEC 2020. [DOI: 10.21071/az.v69i266.5114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
El sistema de producción con bovinos de doble propósito (SPDP) ha sido desarrollado en las zonas tropicales, caracterizado por bajos niveles de eficiencia, aspecto que requiere del análisis de los factores que la afectan. En el presente estudio se analizó la eficiencia técnica (ET) en 271 unidades de producción ubicadas en el estado Zulia, Venezuela, empleando una función de producción de frontera estocástica. Se utilizó como output los ingresos totales ($), y los inputs superficie (ha), unidades animales (UA), unidad trabajo hombre (UTH), y los costos totales ($). Se obtuvo un valor medio de eficiencia técnica de 66,63 %, con un rango de 19,74 a 99,62, lo que indica que existe un amplio margen de mejora. En el modelo de ineficiencia las variables carga animal (UA/ha), y los litros de leche por hectárea (L/ha) fueron significativas, el coeficiente presentó un signo positivo para la carga animal, lo que quiere decir que en la medida que aumenta este parámetro las explotaciones incrementan su ineficiencia, mientras que para los L/ha ocurrió lo contrario. Con base en estos resultados, se plantea la necesidad de determinar el efecto que ejercen las tecnologías de gestión del pastoreo sobre la ET, esto permitiría promover estrategias de manejo que tiendan a optimizar el uso del recurso forrajero, y de esta forma alcanzar mejores niveles de ET en los SPDP.
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Franchi F, Rollini F, Kairouz V, Rivas J, Rivas A, Agarwal M, Briceno M, Wali M, Nawaz A, Silva G, Shaikh Z, Soffer D, Zenni MM, Bass TA, Angiolillo DJ. P1930Pharmacodynamic effects of vorapaxar as an add-on antiplatelet therapy in patients with and without diabetes mellitus: the optimizing anti-platelet therapy in diabetes mellitus (OPTIMUS)-5 study. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz748.0677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Vorapaxar (Vora) is a protease-activated receptor (PAR)-1 inhibitor which when added to dual antiplatelet therapy (DAPT) in patients with a history of myocardial infarction (MI) or with peripheral arterial (PAD) reduces thrombotic cardiovascular events at the expense of increased bleeding. The efficacy of Vora is enhanced in patients with diabetes mellitus (DM) compared to non-DM. However, the differential pharmacodynamic (PD) effects of Vora in DM vs non-DM patients are unknown. Moreover, although withdrawal of aspirin has emerged as a strategy to reduce bleeding when adjunctive antithrombotic therapies are used, the PD effects of Vora after stopping aspirin in DAPT treated patients is unknown.
Purpose
To assess the PD effects of Vora in addition to standard DAPT as well as in combination with clopidogrel following aspirin withdrawal in patients with and without DM.
Methods
This was a prospective parallel-design PD study conducted in post-MI or PAD patients with and without DM. Patients on DAPT with aspirin (81mg/qd) and clopidogrel (75mg/qd) were divided in two groups according to DM status. Each cohort was treated with Vora (2.5mg/qd) in addition to DAPT (i.e., triple therapy) for 30 days and afterwards stopped aspirin and maintained treatment with Vora plus clopidogrel (i.e., dual therapy) for other 30 days. PD testing using 5 different assays was conducted at 3 time-points: baseline (while on DAPT); after 30 days of triple therapy; after 30 days of dual therapy. The primary endpoint was the non-inferiority of CAT (Collagen-ADP-TRAP)-induced aggregation, a marker of global platelet reactivity, of Vora plus clopidogrel (dual therapy) vs Vora plus DAPT (triple therapy).
Results
The PD population was composed of a total of 64 patients (DM, n=30; non-DM, n=34). Although adding Vora to DAPT significantly reduced CAT-induced aggregation, stopping aspirin was associated with an increase in CAT-induced aggregation in both DM (mean difference=12; 95% CI: 3 to 21; p=0.010) and non-DM (mean difference=10; 95% CI: 4 to 16; p=0.003), thus not meeting the primary endpoint of non-inferiority (Figure). The magnitude of such increase was higher in DM compared with non-DM (p=0.036). Although Vora abolished TRAP-induced aggregation in both DM and non-DM patients, it did not affect markers of clot kinetics including speed of thrombin generation. Aspirin withdrawal was associated with a marked increase in makers sensitive to cyclooxygenase-1 (COX-1) blockade; markers of P2Y12 signaling were higher in DM compared to not DM after aspirin withdrawal.
CAT-induced aggregation
Conclusion
Adjunctive treatment with Vora reduces platelet-mediated thrombogenicity without affecting clot kinetics in both DM and non-DM patients while on DAPT. However, platelet-mediated thrombogenicity is increased after aspirin withdrawal, a phenomenon which is enhanced in DM patients underscoring the pivotal contribution of the COX-1 signaling pathway in these high risk patients.
Acknowledgement/Funding
The study was supported in part by an investigator initiated study grant from Merck
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Affiliation(s)
- F Franchi
- University of Florida College of Medicine, Jacksonville, United States of America
| | - F Rollini
- University of Florida College of Medicine, Jacksonville, United States of America
| | - V Kairouz
- University of Florida College of Medicine, Jacksonville, United States of America
| | - J Rivas
- University of Florida College of Medicine, Jacksonville, United States of America
| | - A Rivas
- University of Florida College of Medicine, Jacksonville, United States of America
| | - M Agarwal
- University of Florida College of Medicine, Jacksonville, United States of America
| | - M Briceno
- University of Florida College of Medicine, Jacksonville, United States of America
| | - M Wali
- University of Florida College of Medicine, Jacksonville, United States of America
| | - A Nawaz
- University of Florida College of Medicine, Jacksonville, United States of America
| | - G Silva
- University of Florida College of Medicine, Jacksonville, United States of America
| | - Z Shaikh
- University of Florida College of Medicine, Jacksonville, United States of America
| | - D Soffer
- University of Florida College of Medicine, Jacksonville, United States of America
| | - M M Zenni
- University of Florida College of Medicine, Jacksonville, United States of America
| | - T A Bass
- University of Florida College of Medicine, Jacksonville, United States of America
| | - D J Angiolillo
- University of Florida College of Medicine, Jacksonville, United States of America
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Franchi F, Rollini F, Rivas J, Rivas A, Agarwal M, Briecno M, Wali M, Nawaz A, Silva G, Shaikh Z, Pineda A, Soffer D, Zenni MM, Bass TA, Angiolillo DJ. P1934Platelet inhibitory profiles of prasugrel versus ticagrelor in patients with CYP2C19 loss-of-function genotypes undergoing percutaneous coronary intervention: results of a randomized feasibility study. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz748.0681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Although clopidogrel is the most widely used P2Y12 inhibitor, loss-of-function (LOF) allelic variants located within the hepatic cytochrome P450 (CYP) 2C19 gene lead to attenuated bioactivation, increased rates of high platelet reactivity (HPR), and worse outcomes in patients undergoing percutaneous coronary intervention (PCI). Drug regulating authorities have suggested using alternative P2Y12 inhibitors (i.e., prasugrel or ticagrelor) in these patients. However, tailoring antiplatelet therapy in clinical practice according to results of genetic testing has been limited due to lack of access to promptly available results. Moreover, there are no head-to-head pharmacodynamic (PD) comparisons of prasugrel vs ticagrelor among patients with CYP2C19 LOF alleles.
Purpose
The aim of this study was to evaluate the feasibility of using rapid genetic testing in clinical practice and to compare the PD effects of prasugrel vs ticagrelor in patients undergoing PCI with CYP2C19 LOF alleles.
Methods
This was a prospective, randomized study conducted in patients with stable coronary artery disease and non-ST elevation acute coronary syndrome scheduled for left heart catheterization (LHC) with the intent to undergo PCI. Patients underwent rapid genetic testing using the Spartan RX assay, which defines CYP2C19 genetic status within 1 hour, allowing patients to be genotyped the same day of their LHC. Patients who were carriers of at least one LOF (*2 or *3) allele were randomized to receive either prasugrel [60mg loading dose (LD) - 10mg/day maintenance dose (MD)] or ticagrelor (180mg LD - 90mg b.i.d MD). Blood samples for PD analysis by VerifyNow were collected at 5 time points: baseline (prior to PCI), 30 minutes, 2 hours, 24 hours (or at hospital discharge whichever came first), and 1–4 weeks post-LD. All patients were treated with aspirin. The primary endpoint of our study was the non-inferiority in platelet reactivity, measured as PRU, at 24 hours of prasugrel vs ticagrelor in LOF allele carriers.
Results
A total of 781 consecutive patients scheduled for LHC were genotyped, of whom 223 (28.5%) were carriers of at least one LOF. Of these, 65 patients underwent PCI and randomized to prasugrel (n=32) vs ticagrelor (n=33). PRU levels at 24 hours were 33 vs 36 (prasugrel vs ticagrelor; mean difference = −3; 95% CI: −28 to 22; p=0.814) meeting the primary endpoint of non-inferiority. Both prasugrel and ticagrelor significantly reduced PRU to a similar extent with no differences between groups at all other time points (Figure). Accordingly, HPR rates were low and similar between groups.
PRU by VerifyNow
Conclusion
Rapid genetic testing using the Spartan assay is feasible providing results in a timely fashion in a real-world clinical practice of patients undergoing PCI. Among patients with CYP2C19 LOF carrier status, prasugrel and ticagrelor are associated with similar levels of platelet inhibition.
Acknowledgement/Funding
Genetic testing was provided by Spartan RX
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Affiliation(s)
- F Franchi
- University of Florida College of Medicine, Jacksonville, United States of America
| | - F Rollini
- University of Florida College of Medicine, Jacksonville, United States of America
| | - J Rivas
- University of Florida College of Medicine, Jacksonville, United States of America
| | - A Rivas
- University of Florida College of Medicine, Jacksonville, United States of America
| | - M Agarwal
- University of Florida College of Medicine, Jacksonville, United States of America
| | - M Briecno
- University of Florida College of Medicine, Jacksonville, United States of America
| | - M Wali
- University of Florida College of Medicine, Jacksonville, United States of America
| | - A Nawaz
- University of Florida College of Medicine, Jacksonville, United States of America
| | - G Silva
- University of Florida College of Medicine, Jacksonville, United States of America
| | - Z Shaikh
- University of Florida College of Medicine, Jacksonville, United States of America
| | - A Pineda
- University of Florida College of Medicine, Jacksonville, United States of America
| | - D Soffer
- University of Florida College of Medicine, Jacksonville, United States of America
| | - M M Zenni
- University of Florida College of Medicine, Jacksonville, United States of America
| | - T A Bass
- University of Florida College of Medicine, Jacksonville, United States of America
| | - D J Angiolillo
- University of Florida College of Medicine, Jacksonville, United States of America
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González-Jartín JM, de Castro Alves L, Alfonso A, Piñeiro Y, Vilar SY, Gomez MG, Osorio ZV, Sainz MJ, Vieytes MR, Rivas J, Botana LM. Detoxification agents based on magnetic nanostructured particles as a novel strategy for mycotoxin mitigation in food. Food Chem 2019; 294:60-66. [PMID: 31126505 DOI: 10.1016/j.foodchem.2019.05.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 04/08/2019] [Accepted: 05/01/2019] [Indexed: 01/01/2023]
Abstract
Mycotoxins are toxic compounds that can be present in feed, food and beverages. In this work, 25 magnetic nanostructured materials were developed to remove the main types of mycotoxins from liquid food matrices. The efficiency for binding mycotoxins from contaminated aqueous solutions was studied. Nanocomposites (diameters lower to 15 μm) composed of mixtures of activated carbon, bentonite and aluminium oxide were able to eliminate up to 87% of mycotoxins with an adsorption efficiency of 450 µg/g. On the other hand, spheres with sizes below 3 mm and composed by biopolymers and activated carbon or graphene oxide removed up to 70% of mycotoxins (adsorption of 598 ng/g). These particles were tested for beer detoxification, and spheres composed of alginate and activated carbon or pectin maintain the ability to eliminate toxins from this beverage. Hence, this technology could be a useful tool for the food industry.
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Affiliation(s)
- Jesús M González-Jartín
- Departamento de Farmacología, Facultad de Veterinaria, Universidade de Santiago de Compostela, 27002 Lugo, Spain.
| | - Lisandra de Castro Alves
- Departamento de Física Aplicada, Universidad de Santiago de Compostela, Facultad de Física, 15782 Santiago de Compostela, Spain.
| | - Amparo Alfonso
- Departamento de Farmacología, Facultad de Veterinaria, Universidade de Santiago de Compostela, 27002 Lugo, Spain.
| | - Y Piñeiro
- Departamento de Física Aplicada, Universidad de Santiago de Compostela, Facultad de Física, 15782 Santiago de Compostela, Spain.
| | - Susana Yáñez Vilar
- Departamento de Física Aplicada, Universidad de Santiago de Compostela, Facultad de Física, 15782 Santiago de Compostela, Spain.
| | - Manuel González Gomez
- Departamento de Física Aplicada, Universidad de Santiago de Compostela, Facultad de Física, 15782 Santiago de Compostela, Spain.
| | - Zulema Vargas Osorio
- Departamento de Física Aplicada, Universidad de Santiago de Compostela, Facultad de Física, 15782 Santiago de Compostela, Spain.
| | - María J Sainz
- Departamento de Producción Vegetal y Proyectos de Ingeniería, Facultad de Veterinaria, Universidade de Santiago de Compostela, 27002 Lugo, Spain.
| | - Mercedes R Vieytes
- Departamento de Fisiología, Facultad de Veterinaria, Universidade de Santiago de Compostela, 27002 Lugo, Spain.
| | - J Rivas
- Departamento de Física Aplicada, Universidad de Santiago de Compostela, Facultad de Física, 15782 Santiago de Compostela, Spain.
| | - Luis M Botana
- Departamento de Farmacología, Facultad de Veterinaria, Universidade de Santiago de Compostela, 27002 Lugo, Spain.
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12
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Fernández L, Gamallo M, González-Gómez MA, Vázquez-Vázquez C, Rivas J, Pintado M, Moreira MT. Insight into antibiotics removal: Exploring the photocatalytic performance of a Fe 3O 4/ZnO nanocomposite in a novel magnetic sequential batch reactor. J Environ Manage 2019; 237:595-608. [PMID: 30826641 DOI: 10.1016/j.jenvman.2019.02.089] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 02/13/2019] [Accepted: 02/18/2019] [Indexed: 06/09/2023]
Abstract
The purpose of this research was the preparation and photocatalytic evaluation of a novel nanocomposite (NC) based on Fe3O4/ZnO, to eliminate four persistent antibiotics in surface waters: sulfamethoxazole, trimethoprim, erythromycin and roxithromycin. Prior to the operation of the photocatalytic reactor, the influence of pH (3-9), catalyst concentration (50-800 mg L-1), oxidant dose (0-100 mg L-1) and concentration of different targets (10-100 μg L-1) on the catalytic efficiency was evaluated. The analysis of reaction kinetics showed that degradation processes of the four antibiotics followed a pseudo-first-order kinetic model. Antibiotics adsorption onto the nanocomposite surface depended on their electrostatic nature and played an important role when decreasing the initial concentration of antibiotics. In this context, kinetic rates were higher at lower initial levels of organic pollutants, which is a favourable effect from a practical application perspective. On the other hand, a synergistic effect of the available Fe in the nanocomposite was found, contributing to the oxidation of antibiotics by photo-Fenton as a secondary reaction. Then, a magnetic photocatalytic reactor was operated under optimal conditions. The enhanced photonic efficiency of Fe3O4/ZnO in the system, as well as the ease of the magnetic separation and catalyst reusability, indicate the viability of this reactor configuration.
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Affiliation(s)
- L Fernández
- Dept. of Chemical Engineering, School of Engineering, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain.
| | - M Gamallo
- Dept. of Chemical Engineering, School of Engineering, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - M A González-Gómez
- Laboratory of Magnetism and Nanotechnology, Institute of Technological Research, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - C Vázquez-Vázquez
- Laboratory of Magnetism and Nanotechnology, Institute of Technological Research, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - J Rivas
- Laboratory of Magnetism and Nanotechnology, Institute of Technological Research, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - M Pintado
- Centre of Biotechnology and Fine Chemistry, Faculty of Biotechnology, Universidade Católica Portuguesa, 4202-401, Porto, Portugal
| | - M T Moreira
- Dept. of Chemical Engineering, School of Engineering, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain.
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13
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Soares T, Gónzalez-Gómez M, Rivas J, Freitas P, Carvalho F, Fernandes E, Freitas M. Polyethylemine coated silver nanoparticles induce human neutrophils’ oxidative burst via NADPH oxidase, through the activation of PKC. Toxicol Lett 2018. [DOI: 10.1016/j.toxlet.2018.06.1360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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14
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Munne S, Nakajima S, Najmabadi S, Sauer M, Rivas J, Robins J, Shulman L, Escudero T, Nadal A, Macaso T, Buster J. Chromosomal abnormalities demonstrated by in-vivo conceived& cultured human embryos. Fertil Steril 2018. [DOI: 10.1016/j.fertnstert.2018.07.1186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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15
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Miller MD, Sharma RA, Rivas J, Robbins R, Seixas A, Giardin J, de Leon MJ, Varga AW, Ayappa I, Rapoport D, Osorio RS, Godinho A. 0281 Decreased Objective Total Sleep Time in APOE Ɛ4 Positive Cognitively Normal Elderly. Sleep 2018. [DOI: 10.1093/sleep/zsy061.280] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
| | | | - J Rivas
- New York University, New York, NY
| | | | - A Seixas
- New York University, New York, NY
| | | | - M J de Leon
- Mount Sinai School of Medicine, New York, NY
| | - A W Varga
- Mount Sinai School of Medicine, New York, NY
| | - I Ayappa
- Mount Sinai School of Medicine, New York, NY
| | - D Rapoport
- Mount Sinai School of Medicine, New York, NY
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16
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Rivas J, Sharma R, Miller MD, Godinho A, Ayappa I, Jean-Louis G, Varga AW, Convit A, Osorio RS. 0143 Associations Between Slow Wave Sleep Duration, Insulin Resistance, and Respiratory Effort-Related Arousals in Young Adults. Sleep 2018. [DOI: 10.1093/sleep/zsy061.142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- J Rivas
- NYU School of Medicine, New York, NY
| | - R Sharma
- NYU School of Medicine, New York, NY
| | | | - A Godinho
- NYU School of Medicine, New York, NY
| | - I Ayappa
- Icahn School of Medicine at Mount Sinai, New York, NY
| | | | - A W Varga
- Icahn School of Medicine at Mount Sinai, New York, NY
| | - A Convit
- NYU School of Medicine, New York, NY
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17
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Sharma RA, Miller MD, Kam K, Parekh A, Rivas J, Bubu OM, Varga AW, Iosifescu DV, Osorio RS. 0970 Sleep Spindle Count In Subsyndromal Depressed vs Normal Elderly: A Protective Effect Of Sleep Spindles? Sleep 2018. [DOI: 10.1093/sleep/zsy061.969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- R A Sharma
- New York University School of Medicine, New York, NY
| | | | - K Kam
- Icahn School of Medicine, Mount Sinai, New York, NY
| | - A Parekh
- Icahn School of Medicine, Mount Sinai, New York, NY
| | - J Rivas
- New York University, New York, NY
| | - O M Bubu
- University of South Florida, Tampa, FL
| | - A W Varga
- Icahn School of Medicine, Mount Sinai, New York, NY
| | - D V Iosifescu
- New York University School of Medicine, New York, NY
| | - R S Osorio
- New York University School of Medicine, New York, NY
- New York University School of Medicine, New York, NY
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18
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Sharma RA, Miller MD, Kam K, Parekh A, Bubu OM, Rivas J, Ayappa I, Rapoport DM, Varga AW, Osorio RS. 0695 Objectively Measured Total Sleep Time as a Tool to Detect Longitudinal Changes In Alzheimer’s Disease Neuroimaging Biomarker (FDG PET). Sleep 2018. [DOI: 10.1093/sleep/zsy061.694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
| | | | - K Kam
- Icahn School of Medicine, Mount Sinai, New York, NY
| | - A Parekh
- Icah School of Medicine, Mount Sinai, New York, NY
| | - O M Bubu
- University of South Florida, Tampa, FL
| | - J Rivas
- New York University, New York, NY
| | - I Ayappa
- Icahn School of Medicine, Mount Sinai, New York, NY
| | - D M Rapoport
- Icahn School of Medicine, Mount Sinai, New York, NY
| | - A W Varga
- Icahn School of Medicine, Mount Sinai, New York, NY
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19
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Vargas-Osorio Z, González-Gómez MA, Piñeiro Y, Vázquez-Vázquez C, Rodríguez-Abreu C, López-Quintela MA, Rivas J. Novel synthetic routes of large-pore magnetic mesoporous nanocomposites (SBA-15/Fe 3O 4) as potential multifunctional theranostic nanodevices. J Mater Chem B 2017; 5:9395-9404. [PMID: 32264542 DOI: 10.1039/c7tb01963g] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In this paper, novel magnetic silica nanocomposites were prepared by anchoring magnetite nanoparticles onto the outer surface of mesoporous SBA-15 silica; the magnetic nanoparticles were prepared by microemulsion and solvothermal methods, varying the synthesis conditions in order to control the final physicochemical, textural and magnetic properties. The morphology and mesostructure of the materials were characterized by X-ray diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FTIR), N2 adsorption-desorption, and Transmission and Scanning Electron Microscopy (TEM and SEM). Magnetic silica nanocomposites feature a two-dimensional hexagonal arrangement constituted by a homogeneous pore channel system with diameters between 13 and 18 nm and a Brunauer-Emmett-Teller (BET) surface area higher than 260 m2 g-1. The different morphologies of the samples are given by the presence of diverse magnetic nanoparticle arrangements covalently linked onto the outer surface of the mesoporous silica rods. This confers on them a superparamagnetic behaviour with a magnetic response between 50-80 emu g-1, even though the weight percent of magnetite present in the samples does not exceed 21.7%. In addition, the magnetic nanocomposites exhibit magnetic hyperthermia with moderate Specific Absorption Rate (SAR) values.
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Affiliation(s)
- Z Vargas-Osorio
- Departamento de Física Aplicada, Facultade de Física, Universidade de Santiago de Compostela, E-15782, Santiago de Compostela, Spain.
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20
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Rivas J, Neira V, Mena J, Brito B, Garcia A, Gutierrez C, Sandoval D, Ortega R. Identification of a divergent genotype of equine arteritis virus from South American donkeys. Transbound Emerg Dis 2017; 64:1655-1660. [PMID: 28921885 DOI: 10.1111/tbed.12703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Indexed: 11/28/2022]
Abstract
A novel equine arteritis virus (EAV) was isolated and sequenced from feral donkeys in Chile. Phylogenetic analysis indicates that the new virus and South African asinine strains diverged at least 100 years from equine EAV strains. The results indicate that asinine strains belonged to a different EAV genotype.
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Affiliation(s)
- J Rivas
- Facultad de Ciencias Veterinarias, Departamento de patología y medicina preventiva, Universidad de Concepción, Chillán, Chile
| | - V Neira
- Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
| | - J Mena
- Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
| | - B Brito
- Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
| | - A Garcia
- Laboratorio y Estación Cuarentenaria Pecuaria, Complejo Lo Aguirre, Servicio Agrícola y Ganadero, Santiago, Chile
| | - C Gutierrez
- Laboratorio y Estación Cuarentenaria Pecuaria, Complejo Lo Aguirre, Servicio Agrícola y Ganadero, Santiago, Chile
| | - D Sandoval
- Facultad de Ciencias Veterinarias, Departamento de patología y medicina preventiva, Universidad de Concepción, Chillán, Chile
| | - R Ortega
- Facultad de Ciencias Veterinarias, Departamento de patología y medicina preventiva, Universidad de Concepción, Chillán, Chile
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21
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Meikle ST, Piñeiro Y, Bañobre López M, Rivas J, Santin M. Surface functionalization superparamagnetic nanoparticles conjugated with thermoresponsive poly(epsilon-lysine) dendrons tethered with carboxybetaine for the mild hyperthermia-controlled delivery of VEGF. Acta Biomater 2016; 40:235-242. [PMID: 27134016 DOI: 10.1016/j.actbio.2016.04.043] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 04/19/2016] [Accepted: 04/27/2016] [Indexed: 11/30/2022]
Abstract
UNLABELLED Vascular endothelial growth factor (VEGF) is the growth factor responsible for the triggering of angiogenesis, the process of blood vessel formation supporting the long-term viability of any repaired or regenerated tissue. As the growth factor is effective only when concentration gradients are generated, new shuttles need to be developed that ensure both the control of gradients at the site of tissue repair and the release of VEGF at physiological levels. Magnetic hyperthermia is the production of heat induced by magnetic materials through their exposure to an external oscillating magnetic field. In this paper, magnetic nanoparticles capable of generating controllable hyperthermia were functionalised with hyperbranched poly(epsilon-lysine) peptides integrating in their core parallel thermoresponsive elastin-like peptide sequences and presenting an uppermost branching generation tethered by the zwitterionic amino acid carboxybetaine. The results show that these functionalised magnetic nanoparticles avidly bind VEGF and release it only upon generation of mild-hyperthermic pulses generated by oscillating magnetic filed. The VEGF release occurred in a temperature range at which the elastin-like peptides collapse. It is proposed that, through the application of an external magnetic field, these magnetic carriers could generated gradients of VEGF in vivo and allow its tuned delivery in a number of clinical applications. STATEMENT OF SIGNIFICANCE The present paper for the first time reveals the possibility to control the delivery of VEGF through mild hyperthermia stimuli generated by a oscillating magnetic field. To this purpose, magnetic nanoparticles of high size homogeneity and coated with a thin coating of poly(acrylic acid) were functionalised with a novel class of poly(epsilon lysine) dendrimers integrating in their structure a thermoresponsive amino acid sequence mimicking elastin and exposing at high density a zwitterionic modified amino acid, the carboxybetaine, known to be able to bind macromolecules. Physicochemical and biochemical characterisation elegantly show the link between the thermal properties of the nanoparticles and of the dendrimer change of conformation and how this enable the release of VEGF at temperature values compatible with the growth factor stability.
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Affiliation(s)
- S T Meikle
- Brighton Studies in Tissue-mimicry and Aided Regeneration, Brighton Centre for Regenerative Medicine, University of Brighton, Brighton BN2 4GJ, UK
| | - Y Piñeiro
- Department of Applied Physics, University of Santiago de Compostela University, Santiago de Compostela E15782, Spain
| | - M Bañobre López
- INL - International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
| | - J Rivas
- Department of Applied Physics, University of Santiago de Compostela University, Santiago de Compostela E15782, Spain; INL - International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
| | - M Santin
- Brighton Studies in Tissue-mimicry and Aided Regeneration, Brighton Centre for Regenerative Medicine, University of Brighton, Brighton BN2 4GJ, UK.
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22
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Chisté R, Couto D, Freitas M, Costa V, Almeida A, Lopez-Quintela M, Rivas J, Freitas P, Carvalho F, Fernandes E. The putative pro-inflammatory effect and oxidative stress induced by polyacrylic acid-coated iron oxide nanoparticles in mice: An biodistribution and toxicological study. Toxicol Lett 2015. [DOI: 10.1016/j.toxlet.2015.08.787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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23
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Martins P, Kolen'ko YV, Rivas J, Lanceros-Mendez S. Tailored Magnetic and Magnetoelectric Responses of Polymer-Based Composites. ACS Appl Mater Interfaces 2015; 7:15017-22. [PMID: 26110461 DOI: 10.1021/acsami.5b04102] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The manipulation of electric ordering with applied magnetic fields has been realized on magnetoelectric (ME) materials; however, their ME switching is often accompanied by significant hysteresis and coercivity that represents for some applications a severe weakness. To overcome this obstacle, this work focuses on the development of a new type of ME polymer nanocomposites that exhibits a tailored ME response at room temperature. The multiferroic nanocomposites are based on three different ferrite nanoparticles, Zn0.2Mn0.8Fe2O4 (ZMFO), CoFe2O4 (CFO) and Fe3O4 (FO), dispersed in a piezoelectric copolymer poly(vinylindene fluoride-trifluoroethylene) (P(VDF-TrFE)) matrix. No substantial differences were detected in the time-stable piezoelectric response of the composites (∼-28 pC·N(1-)) with distinct ferrite fillers and for the same ferrite content of 10 wt %. Magnetic hysteresis loops from pure ferrite nanopowders showed different magnetic responses. ME results of the nanocomposite films with 10 wt % ferrite content revealed that the ME induced voltage increases with increasing dc magnetic field until a maximum of 6.5 mV·cm(-1)·Oe(1-), at an optimum magnetic field of 0.26 T, and 0.8 mV·cm(-1)·Oe(1-), at an optimum magnetic field of 0.15 T, for the CFO/P(VDF-TrFE) and FO/P(VDF-TrFE) composites, respectively. In contrast, the ME response of ZMFO/P(VDF-TrFE) exposed no hysteresis and high dependence on the ZMFO filler content. Possible innovative applications such as memories and information storage, signal processing, and ME sensors and oscillators have been addressed for such ferrite/PVDF nanocomposites.
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Affiliation(s)
- P Martins
- †Centro/Departamento de Física, Universidade do Minho, 4710-057 Braga, Portugal
| | - Yu V Kolen'ko
- ‡International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga, 4715-330 Braga, Portugal
| | - J Rivas
- ‡International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga, 4715-330 Braga, Portugal
- ∥Nanomag Laboratory, Department of Applied Physics, Technological Research Institute, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - S Lanceros-Mendez
- †Centro/Departamento de Física, Universidade do Minho, 4710-057 Braga, Portugal
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Prado M, Ortea I, Vial S, Rivas J, Calo-Mata P, Barros-Velázquez J. Advanced DNA- and Protein-based Methods for the Detection and Investigation of Food Allergens. Crit Rev Food Sci Nutr 2015; 56:2511-2542. [DOI: 10.1080/10408398.2013.873767] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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25
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Vilas-Boas V, Guldris N, Carbó-Argibay E, Stroppa DG, Cerqueira MF, Espiña B, Rivas J, Rodríguez-Abreu C, Kolen'ko YV. Straightforward phase-transfer route to colloidal iron oxide nanoparticles for protein immobilization. RSC Adv 2015. [DOI: 10.1039/c5ra08200e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Removal of hydrophobic ligand enables a convenient phase-transfer route to aqueous magnetic nanocolloid that shows excellent protein immobilization capability.
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Affiliation(s)
- V. Vilas-Boas
- UCIBIO-REQUIMTE
- Laboratory of Toxicology
- Biological Sciences Department
- Faculty of Pharmacy
- University of Porto
| | - N. Guldris
- International Iberian Nanotechnology Laboratory
- 4715-330 Braga
- Portugal
| | - E. Carbó-Argibay
- International Iberian Nanotechnology Laboratory
- 4715-330 Braga
- Portugal
| | - D. G. Stroppa
- International Iberian Nanotechnology Laboratory
- 4715-330 Braga
- Portugal
| | | | - B. Espiña
- International Iberian Nanotechnology Laboratory
- 4715-330 Braga
- Portugal
| | - J. Rivas
- Department of Applied Physics
- University of Santiago de Compostela
- Santiago de Compostela 15782
- Spain
| | | | - Yu. V. Kolen'ko
- International Iberian Nanotechnology Laboratory
- 4715-330 Braga
- Portugal
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26
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Vilar-Vidal N, Rivas J, López-Quintela MA. Copper clusters as novel fluorescent probes for the detection and photocatalytic elimination of lead ions. Phys Chem Chem Phys 2014; 16:26427-30. [DOI: 10.1039/c4cp02148g] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new homogeneous assay for a fast, selective and sensitive detection and elimination of lead ions has been developed using copper clusters as novel fluorescent probes in aqueous solutions.
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Affiliation(s)
- N. Vilar-Vidal
- Nanomag Laboratory
- Research Technological Institute
- University of Santiago de Compostela
- Santiago de Compostela, Spain
- INL-International Iberian Nanotechnology Laboratory
| | - J. Rivas
- Nanomag Laboratory
- Research Technological Institute
- University of Santiago de Compostela
- Santiago de Compostela, Spain
- INL-International Iberian Nanotechnology Laboratory
| | - M. A. López-Quintela
- Nanomag Laboratory
- Research Technological Institute
- University of Santiago de Compostela
- Santiago de Compostela, Spain
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27
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Rodrigues D, Bañobre-López M, Espiña B, Rivas J, Azeredo J. Effect of magnetic hyperthermia on the structure of biofilm and cellular viability of a food spoilage bacterium. Biofouling 2013; 29:1225-1232. [PMID: 24088035 DOI: 10.1080/08927014.2013.834893] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
This work evaluated the effect of magnetic hyperthermia (MH) on planktonic cells and biofilms of a major food spoilage bacterium Pseudomonas fluorescens and its performance compared to a conventional direct heating (DH) technique. The results showed that MH had a greater and faster bactericidal effect, promoting a significant reduction in cell viability (≥3 Log CFU) in planktonic and biofilm cells, and leading to a complete eradication of planktonic cells at 55 °C (after only ~8 min). Accordingly, when comparing the same final temperatures, MH was more harmful to the integrity of cell membranes than DH, as observed in confocal laser scanning microscope images. Additionally, scanning electron microscope images revealed that exposure to MH had promoted modifications of the bacterial cell surface as well as of the structure of the biofilm. These results present the possibility of using MH out of the biomedical field as a potential disinfection method in food-related environments.
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Affiliation(s)
- D Rodrigues
- a Institute for Biotechnology and Bioengineering, Centre of Biological Engineering , University of Minho , Braga , Portugal
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28
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Gloria A, Russo T, D'Amora U, Zeppetelli S, D'Alessandro T, Sandri M, Bañobre-López M, Piñeiro-Redondo Y, Uhlarz M, Tampieri A, Rivas J, Herrmannsdörfer T, Dediu VA, Ambrosio L, De Santis R. Magnetic poly(ε-caprolactone)/iron-doped hydroxyapatite nanocomposite substrates for advanced bone tissue engineering. J R Soc Interface 2013; 10:20120833. [PMID: 23303218 DOI: 10.1098/rsif.2012.0833] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In biomedicine, magnetic nanoparticles provide some attractive possibilities because they possess peculiar physical properties that permit their use in a wide range of applications. The concept of magnetic guidance basically spans from drug delivery and hyperthermia treatment of tumours, to tissue engineering, such as magneto-mechanical stimulation/activation of cell constructs and mechanosensitive ion channels, magnetic cell-seeding procedures, and controlled cell proliferation and differentiation. Accordingly, the aim of this study was to develop fully biodegradable and magnetic nanocomposite substrates for bone tissue engineering by embedding iron-doped hydroxyapatite (FeHA) nanoparticles in a poly(ε-caprolactone) (PCL) matrix. X-ray diffraction analyses enabled the demonstration that the phase composition and crystallinity of the magnetic FeHA were not affected by the process used to develop the nanocomposite substrates. The mechanical characterization performed through small punch tests has evidenced that inclusion of 10 per cent by weight of FeHA would represent an effective reinforcement. The inclusion of nanoparticles also improves the hydrophilicity of the substrates as evidenced by the lower values of water contact angle in comparison with those of neat PCL. The results from magnetic measurements confirmed the superparamagnetic character of the nanocomposite substrates, indicated by a very low coercive field, a saturation magnetization strictly proportional to the FeHA content and a strong history dependence in temperature sweeps. Regarding the biological performances, confocal laser scanning microscopy and AlamarBlue assay have provided qualitative and quantitative information on human mesenchymal stem cell adhesion and viability/proliferation, respectively, whereas the obtained ALP/DNA values have shown the ability of the nanocomposite substrates to support osteogenic differentiation.
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Affiliation(s)
- A Gloria
- Institute of Composite and Biomedical Materials, National Research Council, Naples 80125, Italy
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29
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DeMers G, Graydon C, Stein M, Wilson S, Buesch B, Berthiaume S, Lee D, Rivas J, Vilke G, Davis D. 121 Analysis of Inter-facility Transfer Rates After Initiation of a Regional PCI System. Ann Emerg Med 2012. [DOI: 10.1016/j.annemergmed.2012.06.098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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30
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Rivas-Mundina B, Varela-Patino P, Calvo-Fuentes J, Lopez-Quintela MA, Rivas J. Absorption of silver clusters and Nanoparticles by dentin. Med Oral Patol Oral Cir Bucal 2012. [DOI: 10.4317/medoral.17643786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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31
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Massuti B, Jimenez U, Rodriguez Paniagua JM, Pun YW, Cobo M, Carcereny Costa E, Arrabal R, Astudillo J, Barneto IC, De Las Penas R, Baamonde C, Sales G, Gonzalez-Larriba J, Lopez-Vivanco G, Hernando-Trancho F, Pac J, Artal-Cortes A, Rivas J, Rosell R, Sanchez JM. SCAT trial: Phase III Spanish customized adjuvant treatment according BRCA1 mRNA levels in stage II-IIIA non-small cell lung cancer. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.tps208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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32
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Baldomir D, Serantes D, Pereiro M, Botana J, Arias JE, Masunaga SH, Rivas J. Role of the dipolar interaction on the macroscopic state of magnetic nanoparticle systems: a Monte Carlo study. J Nanosci Nanotechnol 2010; 10:2717-2721. [PMID: 20355490 DOI: 10.1166/jnn.2010.1439] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We have performed Monte Carlo simulations to treat the effect of the dipolar interaction in assemblies of superparamagnetic nanoparticles. Our simulations reproduce correctly the increase of the blocking temperature (T(B)) as the concentration increases, as observed experimentally. Interestingly, we have observed a progressive displacement of the M2 versus H/M isotherms (Arrott plots) from the origin as the concentration of nanoparticles increases. Moreover, the curvature of the isotherms at T > T(B) changes from positive to negative slope at high sample concentrations, resembling the shape of a first order phase transition. These results are surprisingly similar to that found in a conventional magnetic phase transition under the effect of a random anisotropy or a random field.
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Affiliation(s)
- D Baldomir
- Instituto de Investigacións Tecnolóxicas, Universidade de Santiago de Compostela, Santiago de Compostela, E-15782 Galiza, Spain
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33
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Serantes D, Baldomir D, Pereiro M, Botana J, Prida VM, Hernando B, Arias JE, Rivas J. Magnetocaloric effect in magnetic nanoparticle systems: how to choose the best magnetic material? J Nanosci Nanotechnol 2010; 10:2512-2517. [PMID: 20355455 DOI: 10.1166/jnn.2010.1424] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Magnetic nanoparticles with controlled magnetocaloric properties are a good candidate to lower the temperature of nanosized systems: they are easy to manipulate and to distribute into different geometries, as wires or planes. Using a Monte Carlo technique we study the entropy change and refrigerant capacity of an assembly of fine magnetic particles as a function of their anisotropy and magnetization, key-parameters of the magnetic behavior of the system. We focus our attention on the anisotropy energy/dipolar energy ratio by means of the related parameter c0 = 2K/M(S)2, where K is the anisotropy constant and M(S) is the saturation magnetization of the nanoparticles. Making to vary the value of co parameter by choosing different K-M(S) combinations, allows us to discuss how the magnetocaloric response of an assembly of magnetic nanoparticles may be tuned by an appropriate choice of the magnetic material composition.
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Affiliation(s)
- D Serantes
- Instituto de Investigacións Tecnolóxicas, Universidade de Santiago de Compostela, Galiza, E-15782, Spain
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34
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Sajan MP, Standaert ML, Rivas J, Miura A, Kanoh Y, Soto J, Taniguchi CM, Kahn CR, Farese RV. Role of atypical protein kinase C in activation of sterol regulatory element binding protein-1c and nuclear factor kappa B (NFkappaB) in liver of rodents used as a model of diabetes, and relationships to hyperlipidaemia and insulin resistance. Diabetologia 2009; 52:1197-207. [PMID: 19357831 PMCID: PMC4766834 DOI: 10.1007/s00125-009-1336-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Accepted: 02/25/2009] [Indexed: 02/06/2023]
Abstract
AIMS/HYPOTHESIS Previous findings in rodents used as a model of diabetes suggest that insulin activation of atypical protein kinase C (aPKC) is impaired in muscle, but, unexpectedly, conserved in liver, despite impaired hepatic protein kinase B (PKB/Akt) activation. Moreover, aPKC at least partly regulates two major transactivators: (1) hepatic sterol receptor binding protein-1c (SREBP-1c), which controls lipid synthesis; and (2) nuclear factor kappa B (NFkappaB), which promotes inflammation and systemic insulin resistance. METHODS In Goto-Kakizaki rats used as a model of type 2 diabetes, we examined: (1) whether differences in hepatic aPKC and PKB activation reflect differences in activation of IRS-1- and IRS-2-dependent phosphatidylinositol 3-kinase (PI3K); (2) whether hepatic SREBP-1c and NFkappaB are excessively activated by aPKC; and (3) metabolic consequences of excessive activation of hepatic aPKC, SREBP-1c and NFkappaB. RESULTS In liver, as well as in muscle, IRS-2/PI3K activation by insulin was intact, whereas IRS-1/PI3K activation by insulin was impaired. Moreover, hepatic IRS-2 is known to control hepatic aPKC during insulin activation. Against this background, selective inhibition of hepatic aPKC by adenoviral-mediated expression of mRNA encoding kinase-inactive aPKC or short hairpin RNA targeting Irs2 mRNA and partially depleting hepatic IRS-2 diminished hepatic SREBP-1c production and NFkappaB activities, concomitantly improving serum lipids and insulin signalling in muscle and liver. Similar improvements in SREBP-1c, NFkappaB and insulin signalling were seen in ob/ob mice following inhibition of hepatic aPKC. CONCLUSIONS/INTERPRETATION In diabetic rodent liver, diminished PKB activation may largely reflect impaired IRS-1/PI3K activation, while conserved aPKC activation reflects retained IRS-2/PI3K activity. Hepatic aPKC may also contribute importantly to excessive SREPB-1c and NFkappaB activities. Excessive hepatic aPKC-dependent activation of SREBP-1c and NFkappaB may contribute importantly to hyperlipidaemia and systemic insulin resistance.
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Affiliation(s)
- M P Sajan
- Research Service, James A Haley Veterans Hospital, Tampa, FL 33612, USA
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35
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Piñeiro Y, López-Quintela MA, Rivas J, Leisner D. Percolation threshold and scattering power law of gelatin gels. Phys Rev E Stat Nonlin Soft Matter Phys 2009; 79:041409. [PMID: 19518235 DOI: 10.1103/physreve.79.041409] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Revised: 01/22/2009] [Indexed: 05/27/2023]
Abstract
Gelation of gelatin was broadly studied by experimental and theoretical methods. Power laws observed on the gel point-mainly obtained by dynamic light scattering (DLS)-are considered to be the signature of some special dynamic phenomena ascribed to the appearance of a percolation cluster. We present here experimental (DLS and rheometric measurements) and Monte Carlo simulation studies showing that the percolation threshold and DLS power-law decay occur on different times. We ascribe the percolation point to the time where the scattering medium mode diverges. This mode is sensitive to the clusters' growth and diverges when the system attains the percolation threshold. The power-law behavior is obtained only in the postpercolation regime.
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Affiliation(s)
- Y Piñeiro
- Department of Applied Physics, University of Santiago de Compostela, Campus Sur, E-15782 Santiago de Compostela, Spain
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36
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Blanco-Canosa S, Rivadulla F, Piñeiro A, Pardo V, Baldomir D, Khomskii DI, Abd-Elmeguid MM, López-Quintela MA, Rivas J. Enhanced dimerization of TiOCl under pressure: spin-Peierls to Peierls transition. Phys Rev Lett 2009; 102:056406. [PMID: 19257532 DOI: 10.1103/physrevlett.102.056406] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2008] [Indexed: 05/27/2023]
Abstract
We report x-ray diffraction and magnetization measurements under pressure combined with ab initio calculations to show that high-pressure TiOCl corresponds to an enhanced Ti3+-Ti3+ dimerized phase existing already at room temperature. Our results demonstrate the formation of a metal-metal bond between Ti3+ ions along the b axis of TiOCl, accompanied by a strong reduction of the electronic gap. The evolution of the dimerization with pressure suggests a crossover from the spin-Peierls to a conventional Peierls situation at high pressures.
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Affiliation(s)
- S Blanco-Canosa
- Departamento de Química-Física, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
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37
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Pardo V, Blanco-Canosa S, Rivadulla F, Khomskii DI, Baldomir D, Wu H, Rivas J. Homopolar bond formation in ZnV2O4 close to a metal-insulator transition. Phys Rev Lett 2008; 101:256403. [PMID: 19113730 DOI: 10.1103/physrevlett.101.256403] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2008] [Indexed: 05/27/2023]
Abstract
Electronic structure calculations for spinel vanadate ZnV2O4 show that partial electronic delocalization in this system leads to a structural instability, with the formation of V-V dimers along the [011] and [101] directions, and readily accounts for the intriguing magnetic structure of this material. The formation of V-V bonds is a consequence of the proximity to the itinerant-electron boundary and is not related to orbital ordering. We discuss how this mechanism naturally couples charge and lattice degrees of freedom in magnetic insulators close to such a crossover.
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Affiliation(s)
- V Pardo
- Departamento de Física Aplicada, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
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Rincon-Garcia A, Rivas J, Chacin B. Single Session Treatment of a Rare Septate Uterus with Endometrial Polyposis. J Minim Invasive Gynecol 2008. [DOI: 10.1016/j.jmig.2008.09.445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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39
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Hoppe CE, Rivadulla F, Vidal-Vidal J, López-Quintela MA, Rivas J. Magnetic relaxation of gamma-Fe2O3 nanoparticles arrangements and electronic phase-segregated systems. J Nanosci Nanotechnol 2008; 8:2883-2890. [PMID: 18681022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Gamma-Fe2O3 nanoparticles have been synthesized and dispersed in a polymeric matrix, forming a series of composites with different concentrations of magnetic particles. The effect of volume polydispersity and dipolar interactions on the relaxation behavior is discussed. We have paid special attention to the dynamic approach to discuss a possible true superspin-glass transition in highly concentrated composites. To avoid the practical limitations that appear in highly concentrated systems of particles, like the formation of aggregates, etc., we have studied the glassy phase that appears spontaneously in certain strongly electronic correlated materials close to a metal-insulator transition. It must be emphasized that from a theoretical point of view these inhomogenous magnetic states could present important advantages over classical dispersions of particles, like field-control of the effective particle size. The results are compared with other recently obtained for classical systems of particles.
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Affiliation(s)
- C E Hoppe
- Departamento de Química-Física, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
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40
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Blanco-Canosa S, Rivadulla F, Pardo V, Baldomir D, Zhou JS, García-Hernández M, López-Quintela MA, Rivas J, Goodenough JB. Enhanced pressure dependence of magnetic exchange in A2+[V2]O4 spinels approaching the itinerant electron limit. Phys Rev Lett 2007; 99:187201. [PMID: 17995433 DOI: 10.1103/physrevlett.99.187201] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2007] [Indexed: 05/25/2023]
Abstract
We report a systematic enhancement of the pressure dependence of T(N) in A(2+)[V(2)]O(4) spinels as the V-V separation approaches the critical separation for a transition to itinerant-electron behavior. An intermediate phase between localized and itinerant-electron behavior is identified in Zn[V(2)]O(4) and Mg[V(2)]O(4) exhibiting mobile holes as large polarons. Partial electronic delocalization, cooperative ordering of V-V pairs in Zn[V(2)]O(4) below T(s) approximately T(N) and dT(N)/dP<0, signals that lattice instabilities associated with the electronic crossover are a universal phenomenon.
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Affiliation(s)
- S Blanco-Canosa
- Departamento de Química-Física, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
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41
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Cerón MC, García-Malea MC, Rivas J, Acien FG, Fernandez JM, Del Río E, Guerrero MG, Molina E. Antioxidant activity of Haematococcus pluvialis cells grown in continuous culture as a function of their carotenoid and fatty acid content. Appl Microbiol Biotechnol 2006; 74:1112-9. [PMID: 17171393 DOI: 10.1007/s00253-006-0743-5] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Revised: 10/31/2006] [Accepted: 11/02/2006] [Indexed: 10/23/2022]
Abstract
The influence of culture conditions on the quality of Haematococcus pluvialis biomass is assessed. Continuously grown cells have been characterised with respect to their astaxanthin, fatty acid content, and antioxidant activity and compared with those of non-growing haematocysts. Moderate limitation of nitrate availability (1.7 mM) under continuous growth conditions favoured the production of reddish palmelloid cells whose extracts possessed antioxidant activity equivalent to that of haematocyst extracts, despite the lower astaxanthin content (0.6%d.wt.), which is compensated by a higher fatty acid level (7.6%d.wt.). Green cells produced under nitrate saturation conditions (>4.7 mM) exhibit only 40% antioxidant activity than palmelloid. In addition, the major fatty acid present in palmelloid cells was oleic acid (40%f.a.), whereas, in both green cells and haematocysts, the main fatty acids were myristic, palmitic, and oleic acid (20-30%f.a. each). Biomass extracts were fractionated and analysed. The antioxidant capacity was a function of both the carotenoid and the fatty acid profiles, the antioxidant capacity of astaxanthin diesters fraction being 60% higher than astaxanthin monoesters fraction and twice than free astaxanthin. In such a way, the evaluation of the quality of H. pluvialis biomass must take into account both variables. When considering the production of H. pluvialis biomass for human consumption, special attention should be paid to the one-step continuous system approach for the generation of cells rich in both astaxanthin and fatty acids, as they have high antioxidant activity but without thick hard cell wall.
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Affiliation(s)
- M C Cerón
- Department of Chemical Engineering, University of Almeria, Cañada San Urbano S/N, 04071 Almeria, Spain
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Casaubon L, Sajan MP, Rivas J, Powe JL, Standaert ML, Farese RV. Contrasting insulin dose-dependent defects in activation of atypical protein kinase C and protein kinase B/Akt in muscles of obese diabetic humans. Diabetologia 2006; 49:3000-8. [PMID: 17028898 DOI: 10.1007/s00125-006-0471-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2005] [Accepted: 07/18/2006] [Indexed: 10/24/2022]
Abstract
AIMS/HYPOTHESIS Insulin-stimulated glucose transport in muscle is impaired in obesity and type 2 diabetes, but alterations in levels of relevant signalling factors, i.e. atypical protein kinase C (aPKC) and protein kinase B (PKB/Akt), are still uncertain. Clamp studies using maximal insulin concentrations have revealed defects in activation of aPKC, but not PKB, in both obese non-diabetic and obese diabetic subjects. In contrast, clamp studies using submaximal insulin concentrations revealed defects in PKB activation/phosphorylation in obese non-diabetic and diabetic subjects, but changes in aPKC were not reported. The aim of this study was to test the hypothesis that dose-related effects of insulin may account for the reported differences in insulin signalling to PKB in diabetic muscle. SUBJECTS AND METHODS We compared enzymatic activation of aPKC and PKB, and PKB phosphorylation (threonine-308 and serine-473) during hyperinsulinaemic-euglycaemic clamp studies using both submaximal (400-500 pmol/l) and maximal (1400 pmol/l) insulin levels in non-diabetic control and obese diabetic subjects. RESULTS In lean control subjects, the submaximal insulin concentration increased aPKC activity and glucose disposal to approximately 50% of the maximal level and PKBbeta activity to 25% of the maximal level, but PKBalpha activity was not increased. In these subjects, phosphorylation of PKBalpha and PKBbeta was increased to near-maximal levels at submaximal insulin concentrations. In obese diabetic subjects, whereas aPKC activation was defective at submaximal and maximal insulin concentrations, PKBbeta activation and the phosphorylation of PKBbeta and PKBalpha were defective at submaximal, but not maximal, insulin concentrations. CONCLUSIONS/INTERPRETATIONS Defective PKBbeta activation/phosphorylation, seen on submaximal insulin stimulation in diabetic muscle, may largely reflect impaired activation of insulin signalling factors present in concentrations greater than those needed for full PKB activation/phosphorylation. Defective aPKC activation, seen at all insulin levels, appears to reflect, at least partly, an impaired action of distal factors needed for aPKC activation, or poor aPKC responsiveness.
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Affiliation(s)
- L Casaubon
- Research Service, James A Haley Veterans Administration Medical Center and Department of Internal Medicine, University of South Florida College of Medicine, Tampa, FL, USA
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43
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Luna V, Casauban L, Sajan MP, Gomez-Daspet J, Powe JL, Miura A, Rivas J, Standaert ML, Farese RV. Metformin improves atypical protein kinase C activation by insulin and phosphatidylinositol-3,4,5-(PO4)3 in muscle of diabetic subjects. Diabetologia 2006; 49:375-82. [PMID: 16395615 DOI: 10.1007/s00125-005-0112-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2005] [Accepted: 08/22/2005] [Indexed: 12/25/2022]
Abstract
AIMS/HYPOTHESIS Metformin is widely used for treating type 2 diabetes mellitus, but its actions are poorly understood. In addition to diminishing hepatic glucose output, metformin, in muscle, activates 5'-AMP-activated protein kinase (AMPK), which alone increases glucose uptake and glycolysis, diminishes lipid synthesis, and increases oxidation of fatty acids. Moreover, such lipid effects may improve insulin sensitivity and insulin-stimulated glucose uptake. Nevertheless, the effects of metformin on insulin-sensitive signalling factors in human muscle have only been partly characterised to date. Interestingly, other substances that activate AMPK, e.g., aminoimidazole-4-carboxamide-1-beta-D: -riboside (AICAR), simultaneously activate atypical protein kinase C (aPKC), which appears to be required for the glucose transport effects of AICAR and insulin. METHODS Since aPKC activation is defective in type 2 diabetes, we evaluated effects of metformin therapy on aPKC activity in muscles of diabetic subjects during hyperinsulinaemic-euglycaemic clamp studies. RESULTS After metformin therapy for 1 month, basal aPKC activity increased in muscle, with little or no change in insulin-stimulated aPKC activity. Metformin therapy for 8 to 12 months improved insulin-stimulated, as well as basal aPKC activity in muscle. In contrast, IRS-1-dependent phosphatidylinositol (PI) 3-kinase activity and Ser473 phosphorylation of protein kinase B were not altered by metformin therapy, whereas the responsiveness of muscle aPKC to PI-3,4,5-(PO(4))(3), the lipid product of PI 3-kinase, was improved. CONCLUSIONS/INTERPRETATION These findings suggest that the activation of AMPK by metformin is accompanied by increases in aPKC activity and responsiveness in skeletal muscle, which may contribute to the therapeutic effects of metformin.
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Affiliation(s)
- V Luna
- ACOS-151, James A. Haley Veterans Hospital, 13000 Bruce B. Downs Blvd, Tampa, FL 33612, USA
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Rivadulla F, Otero-Leal M, Espinosa A, de Andrés A, Ramos C, Rivas J, Goodenough JB. Suppression of ferromagnetic double exchange by vibronic phase segregation. Phys Rev Lett 2006; 96:016402. [PMID: 16486487 DOI: 10.1103/physrevlett.96.016402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2005] [Indexed: 05/06/2023]
Abstract
From Raman spectroscopy, magnetization, and thermal expansion on the system La(2/3)(Ca(1-x)Sr(x))(1/3)MnO3, we have been able to provide a quantitative basis for the heterogeneous electronic model for manganites exhibiting colossal magnetoresistance (CMR). We construct a mean-field model that accounts quantitatively for the measured deviation of T(C)(x) from the T(C) predicted by de Gennes double-exchange in the adiabatic approximation and predicts the occurrence of a first-order transition for a strong coupling regime, in accordance with the experiments. The existence of a temperature interval T(C) < T < T*, where CMR may be found, is discussed in connection with the occurrence of an idealized Griffiths phase.
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Affiliation(s)
- F Rivadulla
- Physical-Chemistry Department, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
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López MCGM, Sánchez EDR, López JLC, Fernández FGA, Sevilla JMF, Rivas J, Guerrero MG, Grima EM. Comparative analysis of the outdoor culture of Haematococcus pluvialis in tubular and bubble column photobioreactors. J Biotechnol 2006; 123:329-42. [PMID: 16406158 DOI: 10.1016/j.jbiotec.2005.11.010] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2005] [Revised: 10/27/2005] [Accepted: 11/23/2005] [Indexed: 10/25/2022]
Abstract
The present paper makes a comparative analysis of the outdoor culture of H. pluvialis in a tubular photobioreactor and a bubble column. Both reactors had the same volume and were operated in the same way, thus allowing the influence of the reactor design to be analyzed. Due to the large changes in cell morphology and biochemical composition of H. pluvialis during outdoor culture, a new, faster methodology has been developed for their evaluation. Characterisation of the cultures is carried out on a macroscopic scale using a colorimetric method that allows the simultaneous determination of biomass concentration, and the chlorophyll, carotenoid and astaxanthin content of the biomass. On the microscopic scale, a method was developed based on the computer analysis of digital microscopic images. This method allows the quantification of cell population, average cell size and population homogeneity. The accuracy of the methods was verified during the operation of outdoor photobioreactors on a pilot plant scale. Data from the reactors showed tubular reactors to be more suitable for the production of H. pluvialis biomass and/or astaxanthin, due to their higher light availability. In the tubular photobioreactor biomass concentrations of 7.0 g/L (d.wt.) were reached after 16 days, with an overall biomass productivity of 0.41 g/L day. In the bubble column photobioreactor, on the other hand, the maximum biomass concentration reached was 1.4 g/L, with an overall biomass productivity of 0.06 g/L day. The maximum daily biomass productivity, 0.55 g/L day, was reached in the tubular photobioreactor for an average irradiance inside the culture of 130 microE/m2s. In addition, the carotenoid content of biomass from tubular photobioreactor increased up to 2.0%d.wt., whereas that of the biomass from the bubble column remained roughly constant at values of 0.5%d.wt. It should be noted that in the tubular photobioreactor under conditions of nitrate saturation, there was an accumulation of carotenoids due to the high irradiance in this reactor, their content in the biomass increasing from 0.5 to 1.0%d.wt. However, carotenoid accumulation mainly took place when nitrate concentration in the medium was below 5.0mM, conditions which were only observed in the tubular photobioreactor. A similar behaviour was observed for astaxanthin, with maximum values of 1.1 and 0.2%d.wt. measured in the tubular and bubble column photobioreactors, respectively. From these data astaxanthin productivities of 4.4 and 0.12 mg/L day were calculated for the tubular and the bubble column photobioreactors. Accumulation of carotenoids was also accompanied by an increase in cell size from 20 to 35 microm, which was only observed in the tubular photobioreactors. Thus it may be concluded that the methodology developed in the present study allows the monitoring of H. pluvialis cultures characterized by fast variations of cell morphology and biochemical composition, especially in outdoor conditions, and that tubular photobioreactors are preferable to bubble columns for the production of biomass and/or astaxanthin.
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Affiliation(s)
- M C García-Malea López
- Department of Chemical Engineering, University of Almería, Cañada San Urbano S/N, Almería 04071, Spain
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Andrés AM, Hernández F, Martínez L, Fernández A, Encinas JL, Avila LF, Luis AL, Rivas J, Olivares P, Tovar JA. [Cardiac function alterations in pectus excavatum]. Cir Pediatr 2005; 18:192-5. [PMID: 16466146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
BACKGROUND Cosmetic deformity and psychological repercusion are the main surgical indications in pectus excavatum. However cardiopulmonary function is subclinically abnormal in some patients. The goal of this paper is to demonstrate that heart response during physical activity improves after surgical correction of pectus excavatum. PATIENTS AND METHODS Fifty five patients were operated upon for pectus excavatum during the last 10 years at our institution. Baseline ecocardiography and isometric effort test (Handgrip) were preoperatively performed in 15 patients (11 males and 4 females) aged from 6 to 15 years (median 9,63). An increase below 12% in cardiac index was considered as positive. In those patients with positive tests, a new test was made 6 months after surgical correction. Pre and postoperative results were compared using non-parametric tests. RESULTS Baseline cardiac index values were normal in all cases (11). Four patients were not included, 2 because of no collaboration (aged 6 and 7 years) and 2 because difficult ecocardiography interpretation (both operated upon for congenital diaphragmatic hernia). Overall, preoperative test was negative in 6 patients and positive in the remaining 5. Postoperative test was made in these 5 patients, and all of them showed an improvement in cardiac index (medium 40,6%, range 25-70) when compared to preoperative values. There was statistically significant association between test values and patient ages. CONCLUSIONS Baseline cardiac index values were normal in children with pectus excavatum, albeit 45,5% of them showed a limited response to exercise. Pectus excavatum repair improves these values, so physiopathological indication as well as cosmetic one should be considered specially in children.
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Affiliation(s)
- A M Andrés
- Departamento de Cirugía Pediátrica y Servicio de Cardiología Pediátrica, Hospital Infantil Universitario La Paz, Madrid.
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Yáñez-Vilar S, Castro-Couceiro A, Rivas-Murias B, Fondado A, Mira J, Rivas J, Señarís-Rodríguez MA. Study of the Dielectric Properties of the Perovskite LaMn0.5Co0.5O3-δ. Z Anorg Allg Chem 2005. [DOI: 10.1002/zaac.200570055] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Vilar SY, Castro-Couceiro A, Rivas-Murias B, Fondado A, Mira J, Rivas J, Señarís-Rodríguez MA. High Dielectric Constant in the Charge-ordered Manganese Oxide CaMn7O12. Z Anorg Allg Chem 2005. [DOI: 10.1002/zaac.200570040] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
Cerebellar hemorrhage after supratentorial surgery is a very infrequent complication. Most cases occur following aneurysm or brain tumor surgery, or evacuation of extracerebral collections. The underlying mechanism of formation of these hematomas is unclear. We present an example of cerebellar hemorrhage following transsphenoidal resection of a pituitary adenoma. To our knowledge, this is the first case reported of hemorrhage in the posterior fossa after a transsphenoidal approach.
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Affiliation(s)
- P Miranda
- Department of Neurosurgery, Hospital 12 de Octubre, Madrid, Spain.
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