Publications by authors named "Leonardo Guimaraes"

The concentrations of toxic metals (TM) were analyzed in 498 samples of agricultural soils used for intensive vegetable cultivation in the watershed of Barracão dos Mendes, Brazil. The goal of this study was to characterize the distribution of these elements and the main natural and anthropogenic factors affecting their accumulation. In general, the average concentrations of TM were higher than the reference quality values for cultivated soils in the region, with the exception of Cr, Co, Ni and Mn, and the average concentration of Cd was ten times greater.

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This paper describes a data collection experiment focused on researching indoor positioning systems using Bluetooth Low Energy (BLE) devices. The study was conducted in a real-world scenario with 150 test points and collected signals from 11 mobile devices. The dataset contains RSSI values from the mobile devices in relation to 15 fixed anchor nodes in the experimentation scenario.

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Large-scale fluid flow in porous media demands intense computations and occurs in the most diverse applications, including groundwater flow and oil recovery. This article presents novel computational strategies applied to reservoir geomechanics. Advances are proposed for the efficient assembly of finite element matrices and the solution of linear systems using highly vectorized code in MATLAB.

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The objective of this work is to physically characterize and analyze synthetic carbonate rocks through microtomography and petrography techniques, focusing on a comparative analysis before and after degradation with a reactive fluid. For this study, physical characterization analysis with computerized microtomography and petrography on the samples before and after the acidification procedure was performed. The petrographic analysis verified an increase in both intergranular and intragranular porosities after dissolution.

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Objective: The purpose of this study was to measure the reliability, internal consistency, construct validity, and floor and ceiling effects of the Brazilian version of the Self-Estimated Functional Inability because of Pain (SEFIP-dance) instrument.

Methods: This was a questionnaire validation study. Both professional dancers and those who use dance as a recreational activity were included in the study.

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Introduction: Spigelian hernia is a rare differential diagnosis of abdominal pain. It affects mainly women above the fifth decade of life, more on the left side than on the right side, usually with comorbidities that lead to an increase in intra-abdominal pressure, described as risk factors for the outbreak of ventral hernias. The content of a ventral hernia might be an epiploic appendix and lead to appendagitis.

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The main goal of an Indoor Positioning System (IPS) is to estimate the position of mobile devices in indoor environments. For this purpose, the primary source of information is the signal strength of packets received by a set of routers. The fingerprint technique is one of the most used techniques for IPSs.

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Background There is a paucity of outcome data on patients who are morbidly obese (MO) undergoing transcatheter aortic valve replacement. We aimed to determine their periprocedural and midterm outcomes and investigate the impact of obesity phenotype. Methods and Results Consecutive patients who are MO (body mass index, ≥40 kg/m, or ≥35 kg/m with obesity-related comorbidities; n=910) with severe aortic stenosis who underwent transcatheter aortic valve replacement in 18 tertiary hospitals were compared with a nonobese cohort (body mass index, 18.

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Article Synopsis
  • Surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR) are both treatments for aortic stenosis, and this study aimed to compare TAVR performed on failed transcatheter valves (TAV-in-TAV) versus surgical valves (TAV-in-SAV).
  • Data from 434 TAV-in-TAV and 624 TAV-in-SAV procedures were analyzed after matching 330 patients from both groups, focusing on procedural success, safety, and 30-day and 1-year mortality rates.
  • Results showed that TAV-in-TAV had higher procedural success rates (72.7% vs. 62.4%) and better aortic valve area and
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Aims: The objective was to compare the incidence and impact on outcomes of measured (PPMM) vs. predicted (PPMP) prosthesis-patient mismatch following transcatheter aortic valve replacement (TAVR).

Methods And Results: All consecutives patients who underwent TAVR between 2007 and 2018 were included.

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Background: The impact of novel alternative access and valve type on radiation exposure during transcatheter aortic valve replacement (TAVR) has not yet been evaluated. This study sought to determine the impact of a transarterial approach and prosthesis type on physician and patient exposure to radiation during TAVR.

Methods: This was a prospective study including 140 consecutive patients undergoing TAVR by transfemoral (n = 102) or transcarotid (TC) (n = 38) access at 2 centers.

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Background: Scarce data exist on transcatheter heart valve (THV) performance evaluated by cardiac magnetic resonance (CMR) in newer generation THV patients. Furthermore, it has been suggested that echocardiographic evaluation after TAVR may inaccurately assess residual AR in some patients. This study aimed to determine the incidence and severity of aortic regurgitation (AR) assessed by CMR in patients undergoing TAVR with the SAPIEN 3 valve, and evaluate the agreement between CMR and transthoracic echocardiography (TTE) on the assessment of AR severity in such patients.

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Objectives: Our study reports the first-in-human experience of a novel approach for left atrial access via the coronary sinus-the percutaneous atriotomy-which is used for left atrial decompression with a dedicated left atrial (LA)-to-coronary sinus (CS) shunt.

Background: Elevated LA pressures contribute to heart failure symptoms, and targeted therapy with atrial shunt devices for LA decompression is an emerging strategy. Current devices reside in the interatrial septum, with risk for right-to-left shunting and systemic embolization.

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The creation of an interatrial shunt has emerged as a new therapy to decompress the left atrium in patients with acute and chronic left heart failure (HF). Current data support the safety of this therapy, and promising preliminary efficacy results have been reported in patients who are refractory to optimal medical/device therapy. This article aims to provide an updated overview and clinical perspective on interatrial shunting for treating different HF conditions, and highlights the potential challenges and future directions of this therapy.

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Background: Transcatheter aortic valve replacement (TAVR) use is increasing in patients with longer life expectancy, yet robust data on the durability of transcatheter heart valves (THVs) are limited. Redo-TAVR may play a key strategy in treating patients in whom THVs fail.

Objectives: The authors sought to examine outcomes following redo-TAVR.

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Introduction And Objectives: We assessed the long-term hemodynamic performance of transcatheter heart valve (THV) by paired transthoracic echocardiography (TTE), and the incidence, characteristics and factors associated with THV structural valve degeneration (SVD).

Methods: A total of 212 patients who underwent transcatheter aortic valve replacement and had a potential follow-up >5 years with at least 1 TTE ≥ 1-year postprocedure were included. All patients had a TTE at 1 to 5 years and 36 had another one at 6 to 10 years.

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Background: Aortic valve calcification severity has been associated with higher rates of aortic regurgitation (AR) following TAVR, but scarce data exist on its impact with the use of newer generation transcatheter heart valves.

Methods: This was a multicenter study including 626 patients with severe aortic stenosis who underwent TAVR with the SAPIEN 3 valve. Patients were divided in 2 groups according to the median index calcium score (iCS) for each sex: high CS (HCS, iCS ≥ median), and low iCS (LCS, iCS < median).

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Background: Transfemoral approach has been commonly used as secondary access in transcatheter aortic valve replacement (TAVR). Scarce data exist on the use and potential clinical benefits of the transradial approach as secondary access during TAVR procedures. The objective of the study is to determine the occurrence of vascular complications (VC) and clinical outcomes according to secondary access (transfemoral versus transradial) in patients undergoing TAVR.

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This study aimed to compare the hemodynamic performance of transcatheter and surgical aortic valves in patients with severe symptomatic aortic stenosis and small aortic annulus (SAA) and to determine the valve hemodynamics according to transcatheter valve type. Consecutive surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR) patients with SAA were case-matched (1:1) on the basis of sex, body surface area, aortic annulus diameter, and left ventricular ejection fraction. A total of 357 patients in each group constituted the final study population.

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Introduction: Among the many techniques available for bariatric surgery, the Mini Gastric Bypass is a safe, technically simple and effective option. However, it may present with postoperative complications, being the perforated gastric ulcer one of the most relevant ones.

Presentation Of Case: A female patient of 41 years of age, with past medical history of a laparoscopic MGB performed 2 year before, presented with 12 hours of sharp and abruptly initiated abdominal pain, with diffuse presentation with suspected perforated acute abdomen after initial medical assessment and examination.

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Objectives: To report on the feasibility and technical differences between coronary procedures performed before and after TAVR with the balloon-expandable Edwards-SAPIEN or the SAPIEN XT valves.

Background: Coronary artery disease (CAD) and aortic stenosis often coexist. Transcatheter aortic valve replacement (TAVR) is emerging as a treatment for younger and lower surgical risk patients who might not present with clinically evident CAD before TAVR.

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About one-half of transcatheter aortic valve replacement (TAVR) candidates have coronary artery disease (CAD), and controversial results have been reported regarding the effect of the presence and severity of CAD on clinical outcomes post-TAVR. In addition to coronary angiography, promising data has been recently reported on both the use of computed tomography angiography and the functional invasive assessment of coronary lesions in the work-up pre-TAVR. While waiting for the results of ongoing randomized trials, percutaneous revascularization of significant coronary lesions has been the routine strategy in TAVR candidates with CAD.

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