Repositorio Universidad Mayor
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Genome sequencing reveals molecular subgroups in oral epithelial dysplasia
No full textThis study aimed to analyze the molecular characteristics of oral epithelial dysplasia (OED), highlighting the pathways and variants of genes that are frequently mutated in oral squamous cell carcinoma (OSCC) and other cancers. Ten archival OED cases were retrieved for retrospective clinicopathological analysis and exome sequencing. Comparative genomic analysis was performed between high-grade dysplasia (HGD) and low-grade dysplasia (LGD), focusing on 57 well-known cancer genes, of which 10 were previously described as the most mutated in OSCC. HGD cases had significantly more variants; however, a similar mutational landscape to OSCC was observed in both groups. CASP8+FAT1/ HRAS, TP53, and miscellaneous molecular signatures were also present. FAT1 is the gene that is most affected by pathogenic variants. Hierarchical divisive clustering showed division between the two groups: "HGD-like cluster" with 4HGD and 2LGD and "LGD-like cluster" with 4 LGD. MLL4 pathogenic variants were exclusively in the "LGD-like cluster". TP53 was affected in one case of HGD; however, its pathway was usually altered. We describe new insights into the genetic basis of epithelial malignant transformation by genomic analysis, highlighting those associated with FAT1 and TP53. Some LGDs presented a similar mutational landscape to HGD after cluster analysis. Perhaps molecular alterations have not yet been reflected in histomorphology. The relative risk of malignant transformation in this molecular subgroup should be addressed in future studies.We are grateful to members of the Diagnostic Service of the Dentistry School at Universidad Mayor, Chile, for their helpful discussions and reading of the text. The sequencing workflow and guidelines were performed by BioinfoGP, Spain. This research was funded by ANID FONDEQUIP grant number EQY220014, PEP I-2022016, and ANID SUBVENCION A INSTALACION EN LA ACADEMIA CONVOCATORIA ANO 2022 grant number 85220068
Imaging the subsurface architecture in porphyry copper deposits using local earthquake tomography
No full textAn essential part of the world's remaining mineral resources is expected to reside deep in the crust or under post-mineralization cover. For porphyry copper deposits, the world's primary source of Cu, Mo, and Re, identifying the dynamic processes that control their emplacement in the upper crust can guide future exploration. Seismic tomography can constrain these processes through imaging deep-seated structures at the regional scale. Here we construct a three-dimensional model of the Vp/Vs ratio, based on arrival times of P and S seismic waves, beneath the Cerro Colorado porphyry Cu-(Mo) deposit in northern Chile. Our images show that low Vp/Vs (similar to 1.55-1.65) anomalies, extending to similar to 5-15 km depth, coincide with the surface expression of known porphyry copper deposits and prospects, as well as delimit structures that host orebodies and related hydrothermal alteration zones. Medium Vp/Vs (similar to 1.68-1.74) and high Vp/Vs (Vp/Vs similar to 1.85) bodies correspond to intermediate-felsic plutonic precursors for porphyry intrusions and mafic magma reservoirs that underlie shallower orebodies, respectively. Imaging these precursor and parental plutons is crucial to the identification of orebodies as they act as the source of fluids for porphyry copper generation. This study demonstrates the potential of local earthquake tomography as a tool to identify future deep mineral resources with minimal environmental impact.This research was funded by the National Agency for Research and Development of Chile (ANID) by Project AFB180004, Project AFB220002 and by the FONDEF ID21I10022 project
Simulated nanoindentation into single-phase fcc FexNi1-x alloys predicts maximum hardness for equiatomic stoichiometry
No full textWe investigate by molecular dynamics simulation the mechanical behavior of concentrated alloys under nanoindentation for the special example of single-phase fcc FexNi1-x alloys. The indentation hardness is maximum for the equiatomic alloy, x=0.5. This finding is in agreement with experimental results on the strength of these alloys under uniaxial strain. We explain this finding with the increase of the unstable stacking fault energy in the alloys towards x=0.5. With increasing Fe content, loop emission from the plastic zone under the indenter becomes less pronounced and the plastic zone features a larger fraction of screw dislocation segments; simultaneously, the length of the dislocation network and the number of atoms in the stacking faults generated in the plastic zone increase. However, the volume of twinned regions in the plastic zone is highest for the elemental solids and decreases for the alloys. This feature is explained by the fact that twinning proceeds by the glide of dislocations on adjacent parallel lattice planes; this concerted motion is less efficient in the alloys. Finally, we find that surface imprints show increasing pile-up heights with increasing Fe content. The present results will be of interest for hardness engineering or generating hardness profiles in concentrated alloys.Open Access funding enabled and organized by Projekt DEAL. IAA and HMU acknowledge support by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)-project number 172116086-SFB 926. IAA also appreciates the financial support from Simulation Science Center Clausthal/Gottingen and the German Research Foundation (DFG) under contract GU1530/11-1, SPP 2315. ORD, DT and EMB thank support from PICTO-UUMM-2019-00048, PIP 2021-2023 11220200102578CO and SIIP-UNCUYO 06/M008-T1
Association Between Cardiovascular Risk Factors And Cognitive Impairment In Adults Aged 60 Years Or Older From Chile: A Cross Sectional Study
No full textDoes Climate Change Alter The Nutrient Trends Of Cedrela Fissilis Vell. Trees In The Southern Brazilian Amazon?
No full textCardiorespiratory Optimal Point As A Submaximal Evaluation Tool In Endurance Athletes: An Exploratory Study
No full textMolecular Survey And Phylogenetic Analysis Of Bartonella Sp., Coxiella Sp., And Hemoplamas In Pudu (Pudu Puda) From Chile: First Report Of Bartonella Henselae In A Wild Ungulate Species
No full textFeasibility Of The 2 Point Method To Determine The Load Velocity Relationship Variables During The Countermovement Jump Exercise
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