In this work, we utilise a combination of theory, computation and experiments to understand the early events related to the nucleation of Ag filaments on α-Ag2WO4 crystals, which is driven by an accelerated electron beam from an electron microscope under high vacuum. The growth process and the chemical composition and elemental distribution in these filaments were analysed in depth at the nanoscale level using TEM, HAADF, EDS and XPS; the structural and electronic aspects were systematically studied in using first-principles electronic structure theory within QTAIM framework. The Ag nucleation and formation on α-Ag2WO4 is a result of the order/disorder effects generated in the crystal by the electron-beam irradiation.
View Article and Find Full Text PDFBackground: The aim of this study is to evaluate the predictors of permanent pacemaker (PPM) implantation after TAVI.
Methods: Between January 2008 and February 2012, 418 patients with severe aortic stenosis underwent TAVI and were enrolled in a Brazilian multicenter registry. After excluding patients who died during the procedure and those with a previous PPM, 353 patients were included in the analysis.
Introduction: In recent years, high-resolution magnetic resonance imaging (MRI) has emerged as a very promising technique for studying atherosclerotic disease in humans.
Aim: In the present study we sought to determine whether MRI allowed for the morphological characterization of the coronary vessel wall and atherosclerotic plaques using histopathological assessment as the reference standard.
Methods: The study population consisted of 13 patients who died of acute myocardial infarction and underwent autopsy.
Background: Polymorphisms in the LPA gene were associated with coronary artery disease (CAD). However, there are differences in the allelic frequencies, Lp(a) levels, and significant association with CAD according to ethnic groups. In this scenario, the main aim of this study was to assess the influence of the LPA polymorphisms on coronary lesions in Brazilian patients.
View Article and Find Full Text PDFAims: The INSPIRON-I trial is a first-in-man evaluation of the safety and efficacy of the Inspiron drug-eluting stent, a sirolimus-eluting stent with abluminal biodegradable polymer coating and thin cobalt-chromium alloy.
Methods And Results: This is a randomised, multicentre comparison between Inspiron and a stent with the same metallic structure but without polymer coating or drug elution (Cronus). The primary objective was to evaluate the in-segment late loss (LLL) at six months.
The increase in global biodiesel production makes imperative the development of sustainable processes for the use of its main by-product, crude glycerol. In this study the feasibility of polyhydroxyalkanoates (PHA) production by a mixed microbial community using crude glycerol as feedstock was investigated. The selected culture had the ability to consume both glycerol and methanol fraction present in the crude.
View Article and Find Full Text PDFHitherto, rings have been found exclusively around the four giant planets in the Solar System. Rings are natural laboratories in which to study dynamical processes analogous to those that take place during the formation of planetary systems and galaxies. Their presence also tells us about the origin and evolution of the body they encircle.
View Article and Find Full Text PDFThe introduction of metallic drug-eluting stents has reduced the risk of restenosis and widened the indications of percutaneous coronary intervention in treatment of coronary artery disease. However, this medical device can induce hypersensitive reaction that interferes with the endothelialization and healing process resulting in late persistent or acquired malapposition of the permanent metallic implant. Delayed endotheliaization and malapposition may lead to late and very late stent thrombosis.
View Article and Find Full Text PDFRecent research on polyhydroxyalkanoates (PHAs) has focused on developing cost-effective production processes using low-value or industrial waste/surplus as substrate. One of such substrates is the liquid fraction resulting from pyrolysis processes, bio-oil. In this study, valorisation of bio-oil through PHA production was investigated.
View Article and Find Full Text PDFAims: We sought to explore whether global and regional scientific output in cardiovascular medicine is associated with economic variables and follows the same trend as medicine and as science overall.
Methods And Results: We registered the number of documents, number of citations, citations per document and the h-index for the first 50 countries according to the h-index (a measure to evaluate both the productivity and impact of the publications) in cardiovascular medicine. Economic variables (gross domestic product [GDP] per capita, % expenditure of the GDP in research and development [R&D] and health) were obtained from the World Bank, the UNESCO, and the World Health Organization.
Catheter Cardiovasc Interv
September 2013
Drug-eluting stents have proven to be effective in reducing the risk of late restenosis. In order to achieve a controlled and prolonged release of the antiproliferative agent, current drug-eluting stents utilise various biodegradable as well as non-erodible polymeric blends to coat the stent surface and to serve as drug carriers. The utilisation of polymeric compounds in current drug-eluting stents may eventually limit their performance as well as their clinical applicability due to the potential induction of undesirable local reactions.
View Article and Find Full Text PDFThe use of biodegradable polymeric coatings has emerged as a potential bioengineering target to improve the vascular compatibility of coronary drug-eluting stents (DESs). This review summarizes the main features and scientific facts about the Supralimus sirolimus-eluting stent (Sahajanand Medical Technologies Ltd, Surat, India), which is a biodegradable polymer-based, sirolimus-eluting metallic stent that was recently introduced for routine use in Europe. The novel stent is built on a stainless steel platform, coated with a blend of biodegradable polymers (poly-l-lactide, poly-dl-lactide-co-glycolide and polyvinyl pyrrolidone; coating thickness is 4-5 µm).
View Article and Find Full Text PDFObjectives: This study was designed to establish the incidence, impact, and predictors of post-transcatheter aortic valve replacement (TAVR) aortic regurgitation (AR).
Background: AR is an important limitation of TAVR with ill-defined predictors and unclear long-term impact on outcomes.
Methods: Studies published between 2002 and 2012 with regard to TAVR were identified using an electronic search and reviewed using the random-effects model of DerSimonian and Laird.
Introduction: The safety and effectiveness of drug-eluting stent (DES) compared with bare metal stents (BMS) for the treatment of saphenous vein graft (SVG) disease is controversial, especially because of the lack of long-term follow-up. The aim of this study was to address the late outcome of DES versus BMS for the treatment of SVG lesions.
Methods: A matched, case-control study included 82 patients in each group.
Purpose: To evaluate hepatic morphological-histological abnormalities in newborns from female rats exposed to ethylenethiourea.
Methods: A randomized study was conducted on fifty-five newborn Wistar rats were studied: 34 in the experimental group, whose mothers had been exposed to 1% ethylenethiourea; and 21 in the control group, whose mothers had received 0.9% physiological solution.
Catheter Cardiovasc Interv
November 2012
Echocardiography
January 2013
Background: Recently, multimodality imaging has been demonstrated to improve the sensitivity of dobutamine stress for the diagnosis of coronary artery disease (CAD).
Objective: We sought to determine the additional value of myocardial perfusion (MP) over wall-motion (WM) analysis for detecting CAD, using real time myocardial contrast echocardiography (RTMCE) and cardiovascular magnetic resonance (CMR), in the same group of patients.
Methods: We studied 42 patients who underwent RTMCE and CMR during high-dose dobutamine stress with early injection of atropine.
BMC Cardiovasc Disord
August 2012
Background: Although the release of cardiac biomarkers after percutaneous (PCI) or surgical revascularization (CABG) is common, its prognostic significance is not known. Questions remain about the mechanisms and degree of correlation between the release, the volume of myocardial tissue loss, and the long-term significance. Delayed-enhancement of cardiac magnetic resonance (CMR) consistently quantifies areas of irreversible myocardial injury.
View Article and Find Full Text PDFThe association between abnormal cervical cytology and HIV infection status in women was evaluated to correlate with CD4 cell count and viral load in HIV-positive patients with the presence of low-grade (LSIL) and high-grade squamous intraepithelial lesion (HSIL). Cervical samples were collected at the Tropical Disease Hospital, Maternal and Child Healthcare Hospital and at the Nascer Cidadão Maternity Hospital in Goiânia, Goiás, Brazil. An Ayre's spatula was used to collect samples from the ectocervix and a cytology brush to collect samples from the endocervix.
View Article and Find Full Text PDFBackground: Semi-quantitative stenosis assessment by coronary CT angiography only modestly predicts stress-induced myocardial perfusion abnormalities. The performance of quantitative CT angiography (QCTA) for identifying patients with myocardial perfusion defects remains unclear.
Methods: CorE-64 is a multicenter, international study to assess the accuracy of 64-slice QCTA for detecting ≥50% coronary arterial stenoses by quantitative coronary angiography (QCA).