53 research outputs found

    Origin of superimposed and curved slickenlines in San Miguelito range, Central MĂ©xico

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    Interactions between intersecting faults cause local perturbations of the stress field in the vicinity of their intersections. Fault intersections are places of stress accumulation, stress relief and refraction of the stress trajectories; the slip vectors near these intersections are deviated from the maximum shear stress resolved by the far-field stress. In an intersecting fault system, superimposed, arc-shaped and zigzag slickenlines can be formed due to interaction between intersecting faults. We propose some mechanisms in which it is possible to recognize that the superimposed and curved slickenlines are produced from curvilinear translational fault motion. The geometrical models presented in this contribution are consistent with the slickenlines distribution observed in the vicinity of intersection lines, measured in the San Miguelito range, Mesa Central, MĂ©xico. Two tectonic phases have been inferred from our slip vector models near the intersection lines, which is consistent with observations of previously published work

    Tilting mechanisms in domino faults of the Sierra de San Miguelito, central Mexico

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    A system of normal faults with similar strike that bound rotated blocks in the Sierra de San Miguelito, central Mexico, was studied to determine the genesis of rotation and to estimate the extensional strain. We show that rigid-body rotation was not the main deformation mechanism of the domino faults in this region. We propose vertical or inclined shear accommodated by slip on minor faults as the mechanism for strain in the blocks. In order to test quantitatively the amount of strain, we calculated the extension assuming vertical shear obtaining ca. ev ~0.20. This value is in good agreement with extensions previously reported for the Mesa Central of MĂ©xico. The bed extension required in this model reaches ca. 33% of the total horizontal extension (i. e. ebed =0.34 ev). Assuming self-similar geometry for fault displacements, it is shown that bed strain required in shear models can be liberated by the small faults. If the strain is calculated using the rigid-body rotation model, the lengthening is underestimated by up to 9%. This case study shows that shear models could be applied in volcanic zones

    Origin of superimposed and curved slickenlines in San Miguelito range, Central MĂ©xico

    Get PDF
    Interactions between intersecting faults cause local perturbations of the stress field in the vicinity of their intersections. Fault intersections are places of stress accumulation, stress relief and refraction of the stress trajectories; the slip vectors near these intersections are deviated from the maximum shear stress resolved by the far-field stress. In an intersecting fault system, superimposed, arc-shaped and zigzag slickenlines can be formed due to interaction between intersecting faults. We propose some mechanisms in which it is possible to recognize that the superimposed and curved slickenlines are produced from curvilinear translational fault motion. The geometrical models presented in this contribution are consistent with the slickenlines distribution observed in the vicinity of intersection lines, measured in the San Miguelito range, Mesa Central, MĂ©xico. Two tectonic phases have been inferred from our slip vector models near the intersection lines, which is consistent with observations of previously published work

    Origin of superimposed and curved slickenlines in San Miguelito range, Central MĂ©xico

    Get PDF
    Interactions between intersecting faults cause local perturbations of the stress field in the vicinity of their intersections. Fault intersections are places of stress accumulation, stress relief and refraction of the stress trajectories; the slip vectors near these intersections are deviated from the maximum shear stress resolved by the far-field stress. In an intersecting fault system, superimposed, arc-shaped and zigzag slickenlines can be formed due to interaction between intersecting faults. We propose some mechanisms in which it is possible to recognize that the superimposed and curved slickenlines are produced from curvilinear translational fault motion. The geometrical models presented in this contribution are consistent with the slickenlines distribution observed in the vicinity of intersection lines, measured in the San Miguelito range, Mesa Central, MĂ©xico. Two tectonic phases have been inferred from our slip vector models near the intersection lines, which is consistent with observations of previously published work

    Modelling and simulation of a thermal storage system based on phase change materials integrated in a tertiary building

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    Decarbonization of the building sector is one of the key challenges to achieve the ambitious goal of carbon neutrality by 2050, established in the European Green Deal. In this sense, current trends focus on the promotion of onsite renewable energy sources, as well as on the electrification of heating and cooling demands and sector coupling approaches through Power-to-heat strategies. This minimizes energy transportation losses while creating an increased need for storage systems. In this scenario, Thermal Energy Storage (TES) systems gain importance and provide the required flexibility, although the experience with high storage periods and volumes, fast response capacity, easy integration into building facilities and cost-effective and environmentally friendly solutions is still scarce. This paper focuses on a TRNSYS (Transient System Simulation Program) modelling and simulation analysis of different integration strategies of a TES system based on Phase Change Materials (PCM) into a real-scale tertiary building. The target building (CARTIF III) is located in Valladolid, Spain, within a Mediterranean climatic area, and incorporates different energy systems including a local photovoltaic (PV) field and a geothermal heat pump (HP). The combination of the PCM storage with the PV and the geothermal HP is studied for the cooling season (in summer) aiming at maximizing the overall system energy efficiency and minimizing the energy import from the grid, thus pursuing a Smart Island concept. Results from this study will feed the solution design for the actual integration project that will be addressed within the framework of a upcoming EU research project

    Deep-sequencing reveals broad subtype-specific HCV resistance mutations associated with treatment failure

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    A percentage of hepatitis C virus (HCV)-infected patients fail direct acting antiviral (DAA)-based treatment regimens, often because of drug resistance-associated substitutions (RAS). The aim of this study was to characterize the resistance profile of a large cohort of patients failing DAA-based treatments, and investigate the relationship between HCV subtype and failure, as an aid to optimizing management of these patients. A new, standardized HCV-RAS testing protocol based on deep sequencing was designed and applied to 220 previously subtyped samples from patients failing DAA treatment, collected in 39 Spanish hospitals. The majority had received DAA-based interferon (IFN) a-free regimens; 79% had failed sofosbuvir-containing therapy. Genomic regions encoding the nonstructural protein (NS) 3, NS5A, and NS5B (DAA target regions) were analyzed using subtype-specific primers. Viral subtype distribution was as follows: genotype (G) 1, 62.7%; G3a, 21.4%; G4d, 12.3%; G2, 1.8%; and mixed infections 1.8%. Overall, 88.6% of patients carried at least 1 RAS, and 19% carried RAS at frequencies below 20% in the mutant spectrum. There were no differences in RAS selection between treatments with and without ribavirin. Regardless of the treatment received, each HCV subtype showed specific types of RAS. Of note, no RAS were detected in the target proteins of 18.6% of patients failing treatment, and 30.4% of patients had RAS in proteins that were not targets of the inhibitors they received. HCV patients failing DAA therapy showed a high diversity of RAS. Ribavirin use did not influence the type or number of RAS at failure. The subtype-specific pattern of RAS emergence underscores the importance of accurate HCV subtyping. The frequency of “extra-target” RAS suggests the need for RAS screening in all three DAA target regions

    Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

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    PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

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    PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

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    This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic
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