115 research outputs found

    Stochastic resonance exploration in current-driven ReRAM devices

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    © 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Advances in emerging resistive random-access memory (ReRAM) technology show promise for its use in future computing systems, enabling neuromorphic and memory-centric computing architectures. However, one aspect that holds back the widespread practical use of ReRAM is the behavioral variability of resistive switching devices. In this context, a radically new path towards ReRAM-based electronics concerns the exploitation of noise and the Stochastic Resonance (SR) phenomenon as a mechanism to mitigate the impact of variability. While SR has been already demonstrated in ReRAM devices and its potential impact has been analyzed for memory applications, related works have only focused on voltage input signals. In this work we present preliminary results concerning the exploration of SR in current-driven ReRAM devices, commercially available by Knowm Inc. Our results indicate that additive noise of amplitude s = 0.125uA can stabilize the cycling performance of the devices, whereas higher noise amplitude improves the HRS-LRS resistance window, thus could affect positively the Bit Error Rate (BER) metric in ReRAM memory applications.Supported by the Chilean research grants FONDECYT INICIACION 11180706 and ANID-Basal FB0008, and by the Spanish MCIN grants PID2019-105658RB-I00, and MCIN/AEI/10.13039/501100011033 grant PID2019-103869RB-C33.Peer ReviewedPostprint (author's final draft

    Geology of the Vicuña Muerta prospect: Structural control and multiple emplacement of Miocene subvolcanic bodies in the eastern border of Southern Puna, Salta

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    En el borde oriental de la Puna Austral, noroeste argentino, se emplazan numerosos intrusivos subvolcánicos de edad miocena inferior a medio con desarrollo de alteración hidrotermal y concentración de minerales de interés económico. Vicuña Muerta forma parte de una serie de intrusivos riolítico-dacíticos porfídicos (Formación Inca Viejo) dispuestos en dirección N-S yemplazados al este de una estructura cenozoica de rumbo N-S con herencia paleozoica inferior desarrollada sobre el borde occidental de las cumbres de Luracatao. Vicuña Muerta (18,9±0,5 Ma K/Ar en sanidina) está conformado por tres cuerpos subvolcánicos porfídicos de composición riolítica emplazados en granitos y gabros ordovícicos (Complejo Eruptivo Oire). Vicu-ña Muerta está delimitado en sus bordes norte y sur por fallas de geometría anastomosada que definen una estructura anularconspicua. Estas estructuras son el resultado de la reactivación andina (20 a 16 Ma según trazas de fisión en apatita) de zonas dedeformación dúctil regionales del Paleozoico inferior (fase Oclóyica) de rumbo N-S que delimitan las cumbres de Luracatao yzonas locales NO-SE en Vicuña Muerta. La reactivación tectónica generó un sistema tipo pop-up regional y fallas transtensivassinestral con desarrollo de fracturas R, R? y P en la zona del prospecto. La geometría de las fallas y el movimiento relativo debloques proporcionaron un ambiente tectónico propicio para el ascenso y emplazamiento de múltiples pulsos de magmas contemporáneo con el levantamiento regional evidenciado por tasas de enfriamiento elevadas. Además, las estructuras controlaron la circulación de fluidos hidrotermales, la distribución de alteraciones en las rocas y la mineralización asociada.On the eastern edge of the southern Puna, northwest Argentina, several Lower-Medium Miocene subvolcanics intrusions with hydrothermal alteration and economic mineral concentrations are located. Vicuña Muerta is part of a group of rhyolitic-dacitic porphyries (Inca Viejo Formation) arranged in a N-S direction and emplaced to the east of a N-S Cenozoic structure with lower Paleozoic inheritance and development on the western edge of the cumbres de Luracatao. Vicuña Muerta comprises three porphyric subvolcanic bodies of rhyolitic composition dated at 18.9±0.5 Ma (K/Ar in Sanidine) and emplaced in Ordovician granites and gabbros (Oire Eruptive Complex). Vicuña Muerta is bounded on its northern and southern edges by anastomosed faults defining an annular geometry structure. These structures are the result of the Andean reactivation (20-16 Ma according to Apatite Fission Tack dating) of lower Paleozoic (Ocloyic phase) regional ductile deformation zones with N-S direction that demarcate cumbres de Luracatao and, also, NW-SE local zones that surround Vicuña Muerta. Tectonic reactivation generated a regional pop-up system and sinistral transtensional faults that developed R, R' and P fractures in the prospect zone. The geometry of the faults and relative movement of tectonic blocks provided a suitable tectonic environment for ascent and emplacement of multiple coeval magma pulses with regional uplift evidenced by high cooling rates. Moreover, structures controlled the circulation of hydrothermal fluids, the alteration distribution of the rocks and the associated mineralization.Fil: Suzaño, Nestor Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigaciones En Energía No Convencional; Argentina. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto Geonorte; ArgentinaFil: Becchio, Raul Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigaciones En Energía No Convencional; Argentina. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto Geonorte; ArgentinaFil: Sola, Alfonso Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigaciones En Energía No Convencional; Argentina. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto Geonorte; ArgentinaFil: Arnosio, Marcelo. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto Geonorte; ArgentinaFil: Nieves, Alexis Iván Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigaciones En Energía No Convencional; Argentina. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto Geonorte; Argentin

    Influência do corticoide na cicatrização do manguito rotador de ratos – Estudo biomecânico

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    ResumoObjetivocomparar a resistência da cicatrização, com relação a tensão máxima, força máxima e força de ruptura, do tendão infraespinhal de ratos submetidos a inoculação de corticoides após a lesão e a reparos experimentais.Métodosforam submetidos 60 ratos Wistar a tenotomia do tendão infraespinhal e suturados. Previamente à cirurgia foram divididos em grupo controle (C), inoculados com soro, e grupo de estudo (E), inoculados com corticoides sobre o tendão. Após o reparo os ratos foram sacrificados em grupos de 10 indivíduos do grupo controle e 10 do grupo de estudo em intervalos de uma semana (C1 e E1), três semanas (C3 e E3) e cinco semanas (C5 e E5). Os ratos foram dissecados com a separação do tendão infraespinhal do úmero. As peças de estudo foram submetidas a teste de tração e avaliadas – tensão máxima (kgf/cm2), força máxima (kgf) e força de ruptura (kgf) – e comparando os grupos de estudo com os grupos controle.Resultadosdentre os ratos sacrificados com uma semana observamos maior tensão máxima do grupo C1 em comparação com o grupo E1. As variáveis força máxima (kgf) e força de ruptura (kgf) não diferiram estatisticamente entre os grupos pesquisados. Da mesma forma, nos ratos sacrificados com três semanas o grupo C3 mostrou apenas resistência maior na tensão máxima em comparação com o grupo E3 (p=0,007). As demais variáveis não apresentaram diferenças. Nos ratos sacrificados com cinco semanas (C5 e E5), nenhum dos parâmetros estudados apresentou diferenças estatísticas.Conclusãoa inoculação com corticoide sobre o manguito rotador levou a diminuição da resistência a tensão máxima da cicatriz pós reparo cirúrgico experimental em uma e três semanas em comparação com os respectivos grupos controle. Os demais parâmetros não tiveram diferença entre os grupos de estudo e os grupos controle.AbstractObjectiveto compare healing strength of the infraspinatus tendon of rats with corticoid inoculation, regarding maximum tension, maximum force and rupture force, after injury and experimental repair.Methods60 Wistar rats were subjected to tenotomy of the infraspinatus tendon, which was then sutured. Before the surgery, they were divided into a control group (C) inoculated with serum and a study group (S) inoculated with corticoids over the tendon. After repair, the rats were sacrificed in groups of 10 individuals in the control group and 10 in the study group at the times of one week (C1 and S1), three weeks (C3 and S3) and five weeks (C5 and S5). The rats were dissected, separating out the infraspinatus tendon with the humerus. The study specimens were subjected to a traction test, with evaluation of the maximum tension (kgf/cm2), maximum force (kgf) and rupture force (kgf), comparing the study group with the respective control groups.Resultsamong the rats sacrificed one week after the procedure, we observed greater maximum tension in group C1 than in group S1. The variables of maximum force (kgf) and rupture force did not differ statistically between the groups investigated. In the same way, among the rats sacrificed three weeks after the procedure, group C3 only showed greater maximum tension than in group S3 (p=0.007), and the other variables did not present differences. Among the rats sacrificed five weeks after the procedure (C5 and S5), none of the parameters studied presented statistical differences.Conclusionwe concluded that corticoid diminished the resistance to maximum tension in the groups sacrificed one and three weeks after the procedure, in comparison with the respective control groups. The other parameters did not show differences between the study and control groups

    Influence of corticoids on healing of the rotator cuff of rats – biomechanical study

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    AbstractObjectiveto compare healing strength of the infraspinatus tendon of rats with corticoid inoculation, regarding maximum tension, maximum force and rupture force, after injury and experimental repair.Methodsa total of 60 Wistar rats were subjected to tenotomy of the infraspinatus tendon, which was then sutured. Before the surgery, they were divided into a control group (C) inoculated with serum and a study group (S) inoculated with corticoids over the tendon. After repair, the rats were sacrificed in groups of 10 individuals in the control group and 10 in the study group at the times of one week (C1 and S1), three weeks (C3 and S3) and five weeks (C5 and S5). The rats were dissected, separating out the infraspinatus tendon with the humerus. The study specimens were subjected to a traction test, with evaluation of the maximum tension (kgf/cm2), maximum force (kgf) and rupture force (kgf), comparing the study group with the respective control groups.Resultsamong the rats sacrificed one week after the procedure, we observed greater maximum tension in group C1 than in group S1. The variables of maximum force (kgf) and rupture force did not differ statistically between the groups investigated. In the same way, among the rats sacrificed three weeks after the procedure, group C3 only showed greater maximum tension than group S3 (p=0.007), and the other variables did not present differences. Among the rats sacrificed five weeks after the procedure (C5 and S5), none of the parameters studied presented statistical differences.Conclusionwe concluded that corticoid diminished the resistance to maximum tension in the groups sacrificed one and three weeks after the procedure, in comparison with the respective control groups. The other parameters did not show differences between the study and control groups

    Efecto del manejo silvícola en la dinámica de la regeneración de Nothofagus alpina, N. obliqua y N. dombeyi bajo diferentes condiciones ambientales

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    La regeneración de los bosques es la base de la renovación y la continuidad de las especies, lo que la convierte en uno de los procesos más importantes en el ciclo de vida de los árboles (Norden 2014). En la dinámica natural, los patrones de regeneración resultan de interacciones entre-especies, moduladas por gradientes ambientales, y el régimen de perturbaciones (Gholami et al. 2018). En bosques mixtos bajo manejo silvícola, la formación de claros produce cambios en los recursos y reguladores ambientales influyendo en la regeneración de las especies y en la estructura del ecosistema forestal (Dezzotti et al. 2003, Sola et al. 2015).EEA BarilocheFil: Mateo, C. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mateo, C. Universidad Nacional del Comahue. Asentamiento Universitario de San Martín de los Andes; ArgentinaFil: El Mujtar, Veronica Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Unidad de Genética Ecológica y Mejoramiento Forestal; ArgentinaFil: El Mujtar, Veronica Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Dezzotti, Alejandro. Universidad Nacional del Comahue. Asentamiento Universitario San Martín de los Andes; Argentina.Fil: Marchelli, Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Unidad de Genética Ecológica y Mejoramiento Forestal; ArgentinaFil: Marchelli, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: González Peñalba, Marcelo. Administración de Parques Nacionales. Parque Nacional Lanín. Departamento de Conservación y Manejo; Argentina.Fil: Lara, M. Administración de Parques Nacionales. Parque Nacional Lanín. Departamento de Conservación y Manejo; Argentina.Fil: Sbrancia, R. Universidad Nacional del Comahue. Asentamiento Universitario San Martín de los Andes; Argentina.Fil: Attis Beltrán, Hernán. Universidad Nacional del Comahue. Asentamiento Universitario San Martín de los Andes; Argentina.Fil: Sola, J. Universidad Nacional de Lomas de Zamora; ArgentinaFil: Sola, Georgina. Universidad Nacional del Comahue. Asentamiento Universitario San Martín de los Andes; Argentina

    Rescue of Advanced Pompe Disease in Mice with Hepatic Expression of Secretable Acid α-Glucosidase.

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    Pompe disease is a neuromuscular disorder caused by disease-associated variants in the gene encoding for the lysosomal enzyme acid α-glucosidase (GAA), which converts lysosomal glycogen to glucose. We previously reported full rescue of Pompe disease in symptomatic 4-month-old Gaa knockout (Gaa-/-) mice by adeno-associated virus (AAV) vector-mediated liver gene transfer of an engineered secretable form of GAA (secGAA). Here, we showed that hepatic expression of secGAA rescues the phenotype of 4-month-old Gaa-/- mice at vector doses at which the native form of GAA has little to no therapeutic effect. Based on these results, we then treated severely affected 9-month-old Gaa-/- mice with an AAV vector expressing secGAA and followed the animals for 9 months thereafter. AAV-treated Gaa-/- mice showed complete reversal of the Pompe phenotype, with rescue of glycogen accumulation in most tissues, including the central nervous system, and normalization of muscle strength. Transcriptomic profiling of skeletal muscle showed rescue of most altered pathways, including those involved in mitochondrial defects, a finding supported by structural and biochemical analyses, which also showed restoration of lysosomal function. Together, these results provide insight into the reversibility of advanced Pompe disease in the Gaa-/- mouse model via liver gene transfer of secGAA.This work was supported by Genethon, the French Muscular Dystro-phy Association (AFM), and Spark Therapeutics. It was also sup-ported by the European Union’s Research and Innovation Programunder grant agreement number 667751 (to F.M.), the EuropeanResearch Council Consolidator Grant under grant agreement number617432 (to F.M.), and Marie Skłodowska-Curie Actions-IndividualFellowship (MSCA-IF) grant agreement number 797144 (to U.C.)S

    Tratamiento mínimamente invasivo para fracturas toracolumbares

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    Introducción: Las técnicas mínimamente invasivas para tratar las fracturas toracolumbares se han desarrollado con el objetivo de reducir, al mínimo, la morbilidad perioperatoria. El objetivo primario de este estudio fue evaluar los resultados clínicos y radiológicos de una serie de pacientes con diagnóstico de fractura toracolumbar por causa traumática tratados con procedimientos mínimamente invasivos. Materiales y Métodos: Se llevó a cabo un análisis retrospectivo de los datos demográficos, radiológicos pre y posoperatorios, y funcionales posoperatorios mediante el índice de Oswestry y la escala analógica visual para dolor, en una serie de pacientes que cumplían los criterios de inclusión. Se registraron las complicaciones y la estancia hospitalaria. Resultados: Se analizaron 15 pacientes (10 hombres) con una edad promedio de 59 años y un seguimiento promedio de 32.9 meses. Los pacientes tenían un dolor promedio posoperatorio de 2/10 y un valor promedio del índice de Oswestry de 14/100. El análisis radiológico mostró un valor promedio preoperatorio de cifosis de 16º, que se corrigió a 10° (p = 0,01). La altura promedio de la vértebra comprometida fue de 18 mm en el preoperatorio y de 21 mm en el último seguimiento (p = 0,02). Hubo tres complicaciones (20%) en tres pacientes. La estancia hospitalaria promedio fue de 9 días. Tres pacientes fueron internados nuevamente dentro de los 90 días de la cirugía. Conclusión: El tratamiento de las fracturas toracolumbares por causa traumática mediante técnicas mínimamente invasivas fue un procedimiento seguro y logró buenos resultados clínicos y radiológicos en el seguimiento a mediano plazo. Nivel de Evidencia: I

    Strain Classification of Mycobacterium tuberculosis Isolates in Brazil Based on Genotypes Obtained by Spoligotyping, Mycobacterial Interspersed Repetitive Unit Typing and the Presence of Large Sequence and Single Nucleotide Polymorphism

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    International audienceRio de Janeiro is endemic for tuberculosis (TB) and presents the second largest prevalence of the disease in Brazil. Here, we present the bacterial population structure of 218 isolates of Mycobacterium tuberculosis, derived from 186 patients that were diagnosed between January 2008 and December 2009. Genotypes were generated by means of spoligotyping, 24 MIRU-VNTR typing and presence of fbpC103, RDRio and RD174. The results confirmed earlier data that predominant genotypes in Rio de Janeiro are those of the Euro American Lineages (99%). However, we observed differences between the classification by spoligotyping when comparing to that of 24 MIRU-VNTR typing, being respectively 43.6% vs. 62.4% of LAM, 34.9% vs. 9.6% of T and 18.3% vs. 21.5% of Haarlem. Among isolates classified as LAM by MIRU typing, 28.0% did not present the characteristic spoligotype profile with absence of spacers 21 to 24 and 32 to 36 and we designated these conveniently as "LAM-like", 79.3% of these presenting the LAM-specific SNP fbpC103. The frequency of RDRio and RD174 in the LAM strains, as defined both by spoligotyping and 24 MIRU-VNTR loci, were respectively 11% and 15.4%, demonstrating that RD174 is not always a marker for LAM/RDRio strains. We conclude that, although spoligotyping alone is a tool for classification of strains of the Euro-American lineage, when combined with MIRU-VNTRs, SNPs and RD typing, it leads to a much better understanding of the bacterial population structure and phylogenetic relationships among strains of M. tuberculosis in regions with high incidence of TB

    An obesogenic feedforward loop involving PPARγ, acyl-CoA binding protein and GABAA receptor

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    Acyl-coenzyme-A-binding protein (ACBP), also known as a diazepam-binding inhibitor (DBI), is a potent stimulator of appetite and lipogenesis. Bioinformatic analyses combined with systematic screens revealed that peroxisome proliferator-activated receptor gamma (PPARγ) is the transcription factor that best explains the ACBP/DBI upregulation in metabolically active organs including the liver and adipose tissue. The PPARγ agonist rosiglitazone-induced ACBP/DBI upregulation, as well as weight gain, that could be prevented by knockout of Acbp/Dbi in mice. Moreover, liver-specific knockdown of Pparg prevented the high-fat diet (HFD)-induced upregulation of circulating ACBP/DBI levels and reduced body weight gain. Conversely, knockout of Acbp/Dbi prevented the HFD-induced upregulation of PPARγ. Notably, a single amino acid substitution (F77I) in the γ2 subunit of gamma-aminobutyric acid A receptor (GABAAR), which abolishes ACBP/DBI binding to this receptor, prevented the HFD-induced weight gain, as well as the HFD-induced upregulation of ACBP/DBI, GABAAR γ2, and PPARγ. Based on these results, we postulate the existence of an obesogenic feedforward loop relying on ACBP/DBI, GABAAR, and PPARγ. Interruption of this vicious cycle, at any level, indistinguishably mitigates HFD-induced weight gain, hepatosteatosis, and hyperglycemia

    Síndrome antisintetasa: reporte de un caso

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    El síndrome antisintetasa es una miopatía inflamatoria autoinmune poco frecuente que se caracteriza por la presencia de autoanticuerpos anti sintetasa ARNt (generalmente anti JO1) asociado frecuentemente a miositis, enfermedad pulmonar intersticial, poliartritis, manos de mecánico y fenómeno de Raynaud. Se reporta el caso de una mujer de 45  años que presenta este síndrome con características fenotípicas de dermatomiositis y responde de forma favorable luego de la administración de tratamiento con glucocorticoides asociado a metotrexato.
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