Caracterização mecânica de um solo fino

A tese que se apresenta, expõe o estudo de aplicabilidade do ensaio edométrico, nomeadamente com recurso à instrumentação de três edómetros, a uma areia siltosa, existente na cidade de Bragança, sendo que objetiva a aplicabilidade do ensaio aos solos de granulometria mais fina da região, com a ressalva de que a curva granulométrica destes se afasta de forma substancial das curvas granulométricas dos solos que por norma são alvo do ensaio edométrico. Objetiva assim o estudo efetuado, a aplicabilidade do ensaio aos solos mais finos oriundos de uma região com predominância de maciço residual granítico. Dado que o solo ensaiado apresenta características pertencentes aos dois tipos de solo mais comuns no âmbito da geotecnia, a presente tese, foca as características fundamentais destes dois grupos, dando especial enfoque aos solos finos. Estando o processo de consolidação, associado à existência de estratos compressíveis no solo de fundação, que muitas vezes dão origem a assentamentos mais ou menos pronunciados, cuja velocidade e magnitude dependem dos parâmetros físicos e mecânicos do solo, e do valor da tensão que neles se induz, a presente tese, para além da determinação dos parâmetros referidos, enfoca, no domínio da mecânica clássica, um estudo acerca da indução de tensões, provenientes de diferentes tipos de fundações superficiais. Em termos de resumo, o estudo efetuado apresenta ainda um exemplo, onde se estima o valor da magnitude de assentamento, em um maciço constituído por dois estratos compressíveis, materializados nos dois solos ensaiados, solicitados pelo valor da tensão induzida por duas sapatas de labo !, afastadas de !, e desenvolvimento infinito ", na consideração de estrato confinado, onde se poderá observar a delicadeza com que estes maciços deverão ser tratados, nomeadamente o baixo valor da tensão a que deverão ser solicitados, para que neles não ocorram assentamentos excessivos, sendo que dos resultados de laboratório obtidos, se permite aferir a aplicabilidade de ensaio aos solos que evidenciem plasticidade, nomeadamente os relativos à região envolvente.This thesis exposes the applicability study of the oedometer test, in particular, with the use of three instrumented oedometers, to an existing silty sand soil, from the city of Braganza, aiming the applicability of the test to the finest soils in the region, considering that the granulometric curve of these soils are substantially different from the granulometric curves of the soils that are usually tested. According to this, the study aim the applicability of the test to the fine grain soils from a region with a predominance of granitic residual soils. Due to the tested soil characteristics belong to the two most common types of soil from geotechnics point of view, this study focuses the fundamental characteristics of these two groups of soils, with a special focus on fine grains soils. Since the consolidation process, associated to the existence of compressible strata, which often give rise to more or less pronounced settlements, whose speed and magnitude depend on the physical and mechanical parameters of the soil, and the magnitude, of the induced stress, the present thesis, in addition to the determination of the referred parameters, focuses, in the field of classical mechanics, a study about the induced stress, coming from different types of surface foundations. In resume terms, the present study also gives an example for the estimate value off the settlement magnitude, on two compressible strata, materialized in the two types of soil tested, with the induced stress from two foundations with ! side length, distanced from ! length, both foundations with infinite side length ", in confined stratum situation, evidencing the delicacy associated to the soil strata, namely the low induced stress value to which they should be requested to avoid major settlements. In addition to this, the results obtained from the laboratory, allows to say, that it´s possible to apply the oedometer test to the soils from the surrounding region that evidence some plasticity

Outcomes of carotid artery stenting at a high-volume Brazilian interventional neuroradiology center

OBJECTIVES: Carotid artery stenting is an emerging revascularization alternative to carotid endarterectomy. However, guidelines have recommended carotid artery stenting only if the rate of periprocedural stroke or death is < 6% among symptomatic patients and < 3% among asymptomatic patients. The aim of this study is to evaluate and compare clinical outcomes of symptomatic and asymptomatic patients who had undergone carotid artery stenting as a first-intention treatment. METHOD: A retrospective analysis of patients who underwent carotid artery stenting by our interventional neuroradiology team was conducted. Patients were divided into two groups: symptomatic and asymptomatic patients. The primary endpoints were ipsilateral ischemic stroke, ipsilateral parenchymal hemorrhage and major adverse cardiac and cerebrovascular events at 30 days. The secondary endpoints included ipsilateral ischemic stroke, ipsilateral parenchymal hemorrhage, ipsilateral transient ischemic attack and major adverse cardiac and cerebrovascular events between the 1- and 12-month follow-ups. RESULTS: A total of 200 consecutive patients were evaluated. The primary endpoints obtained in the symptomatic vs. asymptomatic groups were ipsilateral stroke (2.4% vs. 2.7%, p = 1.00), ipsilateral parenchymal hemorrhage (0.8% vs. 0.0%, p = 1.00) and major adverse cardiac and cerebrovascular events (4.7% vs. 2.7%, p = 0.71). The secondary endpoints obtained in the symptomatic vs. asymptomatic groups were ipsilateral ischemic stroke (0.0% vs. 0.0%), ipsilateral parenchymal hemorrhage (0.0% vs. 0.0%), ipsilateral TIA (0.0% vs. 0.0%, p = 1.00) and major adverse cardiac and cerebrovascular events (11.2% vs. 4.1%, p = 0.11). CONCLUSIONS: In this retrospective study, carotid artery stenting was similarly safe and effective when performed as a first-intention treatment in both symptomatic and asymptomatic patients. The study results comply with the safety requirements from current recommendations to perform carotid artery stenting as an alternative treatment to carotid endarterectomy

Antibacterial and antiviral properties of Chenopodin-derived synthetic peptides

Antimicrobial peptides have been developed based on plant-derived molecular scaffolds for the treatment of infectious diseases. Chenopodin is an abundant seed storage protein in quinoa, an An-dean plant with high nutritional and therapeutic properties. Here, we used computer- and physico-chemical-based strategies and designed four peptides derived from the primary structure of Che-nopodin. Two peptides reproduce natural fragments of 14 amino acids from Chenopodin, named Chen1 and Chen2 and two engineered peptides of the same length were designed based on the Chen1 sequence. The two amino acids of Chen1 containing amide side chains were replaced by ar-ginine (ChenR) or tryptophan (ChenW) to generate engineered cationic and hydrophobic peptides. The evaluation of these 14-mer peptides on Staphylococcus aureus and Escherichia coli showed that Chen1 does not have antibacterial activity up to 512 µM against these strains, while other peptides exhibited antibacterial effects at lower concentrations. The chemical substitutions of glutamine and asparagine by amino acids with cationic or aromatic side chains significantly favoured their antibacterial effects. These peptides did not show significant hemolytic activity. Fluorescence mi-croscopy analysis highlighted the membranolytic nature of Chenopodin-derived peptides. Using molecular dynamic simulations, we found that a pore is formed when multiple peptides are as-sembled in the membrane. Whereas some of them form secondary structures when interacting with the membrane, allowing water translocations during the simulations. Finally, Chen2 and ChenR significantly reduced SARS-CoV-2 infection. These findings demonstrate that Chenopodin is a highly useful template for design, engineering, and manufacturing of non-toxic, antibacterial, and antiviral peptides

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p&lt;0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p&lt;0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

Oxidative Stress in Chronic Hepatitis C: The Effect of Interferon Therapy and Correlation with Pathological Features

AIMS: To evaluate the oxidative stress parameters before, during and after interferon treatment

Outcomes of carotid artery stenting at a high-volume Brazilian interventional neuroradiology center

OBJECTIVES: Carotid artery stenting is an emerging revascularization alternative to carotid endarterectomy. However, guidelines have recommended carotid artery stenting only if the rate of periprocedural stroke or death is < 6% among symptomatic patients and < 3% among asymptomatic patients. The aim of this study is to evaluate and compare clinical outcomes of symptomatic and asymptomatic patients who had undergone carotid artery stenting as a first-intention treatment. METHOD: A retrospective analysis of patients who underwent carotid artery stenting by our interventional neuroradiology team was conducted. Patients were divided into two groups: symptomatic and asymptomatic patients. The primary endpoints were ipsilateral ischemic stroke, ipsilateral parenchymal hemorrhage and major adverse cardiac and cerebrovascular events at 30 days. The secondary endpoints included ipsilateral ischemic stroke, ipsilateral parenchymal hemorrhage, ipsilateral transient ischemic attack and major adverse cardiac and cerebrovascular events between the 1- and 12-month follow-ups. RESULTS: A total of 200 consecutive patients were evaluated. The primary endpoints obtained in the symptomatic vs. asymptomatic groups were ipsilateral stroke (2.4% vs. 2.7%, p = 1.00), ipsilateral parenchymal hemorrhage (0.8% vs. 0.0%, p = 1.00) and major adverse cardiac and cerebrovascular events (4.7% vs. 2.7%, p = 0.71). The secondary endpoints obtained in the symptomatic vs. asymptomatic groups were ipsilateral ischemic stroke (0.0% vs. 0.0%), ipsilateral parenchymal hemorrhage (0.0% vs. 0.0%), ipsilateral TIA (0.0% vs. 0.0%, p = 1.00) and major adverse cardiac and cerebrovascular events (11.2% vs. 4.1%, p = 0.11). CONCLUSIONS: In this retrospective study, carotid artery stenting was similarly safe and effective when performed as a first-intention treatment in both symptomatic and asymptomatic patients. The study results comply with the safety requirements from current recommendations to perform carotid artery stenting as an alternative treatment to carotid endarterectomy