Browsing by Author "Espinoza, C."
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- ItemCisgenesis and Intragenesis: New tools For Improving Crops(2013) Espinoza, C.; Schlechter, R.; Herrera, D.; Torres, E.; Serrano, A.; Medina, C.; Arce-Johnson, P.Genetically Modified Organisms (GMO) could be the answer for many relevant problems affecting crops. However, improving crops through GMO is also often associated with safety concerns, environmental risks and health issues due to the presence of foreign DNA. These limitations have prompted the development of alternative technologies. Recently, cisgenesis and intragenesis have been developed as new tools aimed to modify crops. While cisgenesis involves genetic modification using a complete copy of natural genes with their regulatory elements that belong exclusively to sexually compatible plants, intragenesis refers to the transference of new combinations of genes and regulatory sequences belonging to that particular species. So far, application of cisgenesis and intragenesis as alternatives to conventional transgenesis are limited to a few species, mainly due to the lack of knowledge of the regulatory sequences required. The grape is one of the most cultivated crops worldwide and is the most economically relevant crop in Chile. Its genomic sequence has been completed, making available new sources of information to improve grape traits by genetic manipulation. This review is focused on the current alternatives to transgenesis in plants, including new approaches to develop marker-free crops, their application to economically relevant crops and future perspectives in the area. Also, the identification of grapevine promoters with a wide range of expression profiles is shown. The expression pattern of these genes was analyzed in different tissues and developmental stages, as well as under several stresses and stimuli, giving a broad range of expression patterns, including genes expressed exclusively during ripening, in response to sugars, senescence and biotic stress, among others. Genes with strong and constitutive expression were also identified. Functional analysis using reporter genes has been conducted in order to confirm the promoter's transcription activity, opening new possibilities for developing cisgenic/intragenic grapevines.
- ItemCorrigendum to ‘Simple dual-QCM method to control CH3NH3I deposition for reproducible vacuum-processed halide perovskite photovoltaic devices’ [Mater. Lett. 321 (2021) 132459] (Materials Letters (2022) 321, (S0167577X22008126), (10.1016/j.matlet.2022.132459))(2023) Espinoza, C.; Barría-Cáceres, F.; Angel Figueroa, Felipe Alfonso
- ItemEffect of microstructure on thermoelastic stresses in Al2O3/Ti(C,N,O)/Ti (C,N) coating systems studied by Finite Element Method simulations(2021) Espinoza, C.; Ramos-Moore, E.; Celentano, D.Finite Element Method (FEM) simulations were performed to qualitatively study the effects of texture anisotropy, bonding interlayer thickness, and average crack spacing on the evolution of thermoelastic stress in coatings systems containing Al2O3 and Ti(C,N) layers bonded with a Ti(C,N,O) interlayer. Commercial WC-Co tools were considered as substrates, including a superficial gamma-free phase. Significant stress differences are observed between the Al2O3 and Ti(C,N) layers due to differences in the Coefficient of Thermal Expansion (CTE) relative to the substrate. No significant differences were observed when considering axis-dependent CTE and elastic data of the Al2O3 layer, nor introducing a Ti(C,N,O) interlayer. Cracks across the coatings resulted in a significant reduction of stress in both layers, reaching values near zero in the cracks' vicinity, this effect being more prominent for shorter crack distances. Differences among our FEM simulations and experimental residual stress reports on similar systems highlight the need to develop more complex models to understand the effect of nucleation processes and microstructure on the residual stress. (C) 2021 Elsevier B.V. All rights reserved.
- ItemGene Expression Associated With Compatible Viral Diseases in Grapevine Cultivars(2007) Espinoza, C.; Arce Johnson, Jorge Patricio
- ItemIn-situ high temperature stress analysis of Ti(C,N) coatings on functionally graded cemented carbides by energy dispersive synchrotron X-ray diffraction(2016) García, J.; Pinto, H.; Ramos Moore, Esteban; Espinoza, C.; Östby, J.; Coelho, R.
- ItemInfluence of crystallographic texture on friction in a-Al2O3/Ti(C,N) ceramic tool coatings(2022) Ramos-Moore, E.; Rosenkranz, A.; Diaz-Droguett, D. E.; Espinoza, C.; El Azahri, I.; Muecklich, F.This work explores the influence of the crystallographic texture on the resulting frictional response in two ceramic coatings systems containing top alpha-Al2O3 layer with no and fiber texture. The microstructure was analyzed by electron backscatter diffraction, the surface roughness was characterized by white light interferometry, and the micro hardness was measured by standard Vickers testing. The coefficient of friction (COF) was measured using ball-on-disk tribometry under linear reciprocating sliding motion. Our results verified a strong correlation between the crystallographic texture of the top alpha-Al2O3 layer and the resulting COF. This effect can be mainly attributed to the lowest critical shear stress within the basal dislocation slip {0001} < 11-20 >, which facilitates the generation of plastic deformation at the top surface layer. This work highlights the understanding of the complex correlations between microstructure and tribological performance of ceramic coatings.
- ItemInspection of the Grapevine BURP Superfamily Highlights an Expansion of RD22 Genes with Distinctive Expression Features in Berry Development and ABA-Mediated Stress Responses(2014) Matus, J.; Aquea Zeballos, José Felipe; Espinoza, C.; Vega C., Andrea; Cavallini, E.; Canon Rodriguez, H.; Serrano, J.; Battista Tornielli, G.; Arce Johnson, Jorge Patricio; Dal Santo, S.
- ItemOmics Approaches for Understanding Grapevine Berry Development: Regulatory Networks Associated with Endogenous Processes and Environmental Responses(2017) Serrano, A.; Espinoza, C.; Armijo, G.; Inostroza, C.; Poblete, E.; Meyer Regueiro, Carlos José; Arce Medina, Aníbal Andrés; Parada, F.; Santibanez, C.; Arce Johnson, Jorge Patricio
- ItemSecond nearest neighbor modified embedded atom method interatomic potentials for TiCxN1-x ternary systems(2024) Araya-Barr, A.; Garcia, G.; Arias-Camacho, I.; Espinoza, C.; Lee, Byeong-Joo; Ramos-Moore, E.New potential parameters for the Ti-C-N ternary system based on the second nearest neighbor modified embedded atom method (2NN MEAM) are reported. The parameters were developed starting from published binary systems for Ti-C and Ti-N and fitted using published data of lattice constants, formation enthalpy, bulk modulus, elastic constants, and surface properties for several C/N ratios in the cubic B1 structure. The simulated systems using the new parameters show agreement with structural and elastic experimental and first-principles values. Our results highlight novel methods to calculate several mechanical and thermal properties of TiCxN1-x systems.
- ItemSenescence-associated genes induced during compatible viral interactions with grapevine and Arabidopsis(2007) Espinoza, C.; Medina, C.; Somerville, S.; Arce-Johnson, P.The senescence process is the last stage in leaf development and is characterized by dramatic changes in cellular metabolism and the degeneration of cellular structures. Several reports of senescence-associated genes (SAGs) have appeared, and an overlap in some of the genes induced during senescence and pathogen infections has been observed. For example, the enhanced expression of SAGs in response to diseases caused by fungi, bacteria, and viruses that trigger the hypersensitive response (HR) or during infections induced by virulent fungi and bacteria that elicit necrotic symptoms has been observed. The present work broadens the search for SAGs induced during compatible viral interactions with both the model plant Arabidopsis thaliana and a commercially important grapevine cultivar. The transcript profiles of Arabidopsis ecotype Uk-4 infected with tobacco mosaic virus strain Cg (TMV-Cg) and Vitis vinifera cv. Carmenere infected with grapevine leafroll-associated virus strain 3 (GLRaV-3) were analysed using microarray slides of the reference species Arabidopsis. A large number of SAGs exhibited altered expression during these two compatible interactions. Among the SAGs were genes that encode proteins such as proteases, lipases, proteins involved in the mobilization of nutrients and minerals, transporters, transcription factors, proteins related to translation and antioxidant enzymes, among others. Thus, part of the plant's response to virus infection appears to be the activation of the senescence programme. Finally, it was demonstrated that several virus-induced genes are also expressed at elevated levels during natural senescence in healthy plants.
- ItemSenescence-associated genes induced during compatible viral interactions with grapevine and Arabidopsis(2007) Espinoza, C.; Arce Johnson, Jorge Patricio
- ItemSeroprevalencia de Bartonella henselae en personas con riesgo ocupacional(2016) Abarca Villaseca, Katia; Troncoso, I.; Fischer, C.; Arteaga, F.; Espinoza, C.; Azócar, T.
- ItemSynthesis and characterization of a 2,3-dialkoxynaphthalene-based conjugated copolymer via direct arylation polymerization (DAP) for organic electronics(2020) Jessop, I.A.; Chong, A.; Graffo, L.; Camarada, M.B.; Espinoza, C.; Angel Figueroa, Felipe Alfonso; Saldías, C.; Tundidor-Camba, A.; Terraza, C.A.
- ItemVariación espacio-temporal en la composición del ensamble de macroalgas del intermareal rocoso de Maitencillo, Valparaíso, costa central de Chile(2018) Contreras Porcía, Loretto Matilde; Zapata, J.; Betancourtt, C.; Latorre, N.; Anguita, C.; Castañeda, F.; Meynard, A.; Fierro, C.; Espinoza, C.; Guajardo, E.; Núñez, A.; Salas, N.; González, C.; Ramírez, M. E.
- ItemWnt signaling pathway improves central inhibitory synaptic transmission in a mouse model of Duchenne muscular dystrophy(2016) Fuenzalida, M.; Espinoza, C.; Pérez, M.; Tapia, C.; Cuitino, L.; Brandan, Enrique; Inestrosa Cantín, Nibaldo