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Online learning has become an increasingly expected and popular component for education of the modern-day adult learner, including the medical provider. In light of the recent coronavirus pandemic, there has never been more urgency to establish opportunities for supplemental online learning. Heart University aims to be “the go-to online resource” for e-learning in CHD and paediatric-acquired heart disease. It is a carefully curated open access library of paedagogical material for all providers of care to children and adults with CHD or children with acquired heart disease, whether a trainee or a practising provider. In this manuscript, we review the aims, development, current offerings and standing, and future goals of Heart University.
We retrospectively reviewed all the children with right ventricular outflow tract obstruction, hypoplastic pulmonary annulus, and pulmonary arteries who underwent stenting of the right ventricular outflow tract for hypercyanotic spells at our institution between January, 2008 and December, 2013; nine patients who underwent cardiac catheterisation at a median age of 39 days (range 12–60 days) and weight of 3.6 kg (range 2.6–4.3 kg) were identified. The median number of stents placed was one stent (range 1–4). The median oxygen saturation increased from 60% to 96%. The median right pulmonary artery size increased from 3.3 to 5.5 mm (−2.68 to −0.92 Z-score), and the median left pulmonary artery size increased from 3.4 to 5.5 mm (−1.93 to 0 Z-scores). Among all, one patient developed transient pulmonary haemorrhage, and one patient had pericardial tamponade requiring drainage. Complete repair of tetralogy of Fallot +/− atrioventricular septal defect or double-outlet right ventricle was achieved in all nine patients. Transcatheter stent alleviation of the right ventricular outflow tract obstruction resolves hypercyanotic spells and allows reasonable growth of the pulmonary arteries to facilitate successful surgical repair. This represents a viable alternative to placement of a systemic-to-pulmonary artery shunt, particularly in small neonates.
We performed a study to determine rates of reinfection in three groups followed for 2 years after successful treatment: American Indian/Alaska Native (AI/AN) persons living in urban (group 1) and rural (group 2) communities, and urban Alaska non-Native persons (group 3). We enrolled adults diagnosed with H. pylori infection based on a positive urea breath test (13C-UBT). After successful treatment was documented at 2 months, we tested each patient by 13C-UBT at 4, 6, 12 and 24 months. At each visit, participants were asked about medication use, illnesses and risk factors for reinfection. We followed 229 persons for 2 years or until they became reinfected. H. pylori reinfection occurred in 36 persons; cumulative reinfection rates were 14·5%, 22·1%, and 12·0% for groups 1, 2, and 3, respectively. Study participants who became reinfected were more likely to have peptic ulcer disease (P = 0·02), low education level (P = 0·04), or have a higher proportion of household members infected with H. pylori compared to participants who did not become reinfected (P = 0·03). Among all three groups, reinfection occurred at rates higher than those reported for other US populations (<5% at 2 years); rural AI/AN individuals appear to be at highest risk for reinfection.
We describe a case of a baby girl born with hypoplastic left heart syndrome consisting of mitral atresia, aortic atresia, hypoplastic ascending aorta, and left ventricle. The pulmonary arteries were hypoplastic, measuring 3 mm. Fluorescence in situ hybridisation analysis demonstrated a microduplication of chromosome 22q11.2. Subsequent array comparative genomic hybridisation showed a gain of 2.3 Mb in one copy of chromosome 22q at band 22q11.21. The proband underwent a successful Norwood procedure with Sano shunt and subsequently underwent bi-directional Glenn shunt and Fontan procedure. This report highlights the association between hypoplastic left heart syndrome with hypoplastic pulmonary arteries and chromosome 22q11.21 microduplication.
The quantity of methane in Mars' atmosphere, and the potential mechanism(s) responsible for its production, are still unknown. In order to test viable, abiotic, methangenic processes, we experimentally investigated two possible impact mechanisms for generating methane. In the first suite of experiments, basaltic rocks were impacted at 5 km s−1 and the quantity of gases (CH4, H2, He, N2, O2, Ar and CO2) released by the impacts was measured. In the second suite of experiments, a mixture of water ice, CO2 ice and anhydrous olivine grains was impacted to see if the shock induced rapid serpentinization of the olivine, and thus production of methane. The results of both suites of experiments demonstrate that impacts (at scales achievable in the laboratory) do not give rise to detectably enhanced quantities of methane release above background levels. Supporting hydrocode modelling was also performed to gain insight into the pressures and temperatures occurring during the impact events.
Sheep, after infection with louping ill virus and after re-infection with the same strain of virus 19–21 months later, were bled at intervals and their sera examined for neutralizing and haemagglutinin-inhibiting antibodies. Each antibody type was measured by the constant serum/variable virus and constant virus/variable serum methods. The persistence of each type of antibody and its significance in epidemiological studies is discussed. The relationship of antibody levels in ewes and their lambs was also examined.
One-micron plastic "thick" sections, usually stained with toluidine blue, are indispensable light microscopic adjuvants for the selection and evaluation of tissue blocks prior to electron microscopy. Plastic thick sections may also be the only practical alternative to routine histologic sections when tissue specimens are limited or too small for processing in paraffin. In all cases, however, plastic sections provide superior light microscopic resolution compared to paraffin sections, but lack the compatibility with the wide variety of special stains that make paraffin sections so versatile.
Flash lamp annealing in the millisecond regime of heteroepitaxial silicon carbide on silicon structures involves melting the Si below the SiC layer, but the deep facetted nature of the solid-liquid interface leads to unacceptable surface roughness. This paper describes a method of controlling melting by implanting a high dose of carbon or germanium at a controlled depth below the Si/SiC interface, which significantly alters the melting characteristics of the silicon. Results confirm the effectiveness of these approaches for increasing surface uniformity, making liquid phase processing compatible with standard device fabrication techniques. A thermal model has also been developed to describe this process and results indicate that the theoretical work is consistent with the experimental evidence. The model is a valuable tool for predicting onset of melting, maximum temperatures and process windows for liquid phase epitaxy.
The Radiological Protection Institute of Ireland has monitored levels of anthropogenic radionuclides in the Irish marine environment for over 20 years. While the primary objective of the monitoring programme is to assess the exposure of the Irish population resulting from the presence of these radionuclides in the marine environment, the programme also aims to assess the geographical distribution and temporal variations of the radionuclides. The programme involves the routine sampling of and testing for radioactivity in fish, shellfish, seaweed, sediments and seawater. The data generated in the course of this programme, as well as in a separate study of changing plutonium isotopic ratios in Fucus vesiculosus from the west coast of Ireland, were used to estimate transport times from the Sellafield nuclear fuel reprocessing plant to various locations on the Irish coastline. For conservative radionuclides, transit times of 5-6 months to the NE coast of Ireland, 1-3 years to the south coast of Ireland and 3-8 years to the west coast were calculated. In contrast, for plutonium, the Sellafield signal was not observed on the west coast until the late 1980s/early 1990s.
Transgenic mice that overexpress arginase-I in their small-intestinal enterocytes suffer from a pronounced, but selective decrease in circulating arginine levels during the suckling period, resulting in impaired growth and development of hair, muscle and immune system. In the present study, we tested the hypothesis that the arginine-deficiency phenotype is caused by arginine-specific post-translational modifications, namely, an increase in the degree of mono-ADP-ribosylation of proteins because of reduced competition by free arginine residues and/or an increase in protein-tyrosine nitration because of an increased O2− production by NO synthases in the presence of limiting amounts of arginine. Arginine ADP-ribosylation and tyrosine nitration of proteins in the affected organs were assayed by Western blot analysis, using specific anti-ADP-ribosylarginine and protein-nitrotyrosine antisera. The composition of the group of proteins that were preferentially arginine ADP-ribosylated or tyrosine-nitrated in the respective organs was strikingly similar. Arginine-deficient mice differed from their controls in a reduced ADP-ribosylation of a 130 kDa and a 65 kDa protein in skin and an increased protein nitration of an 83 kDa protein in bone marrow and a 250 kDa protein in spleen. Since only 20 % of the visualised proteins were differentially modified in a subset of the affected organs, our findings appear to rule out these prominent arginine-dependent post-translational protein modifications as mediators of the characteristic phenotype of severely arginine-deficient mice.
Wafer-level three-dimensional (3D) integration is an emerging technology to increase the performance and functionality of integrated circuits (ICs). Aligned wafer-to-wafer bonding with dielectric polymer layers (e.g., benzocyclobutene (BCB)) is a promising approach for manufacturing of 3D ICs, with minimum bonding impact on the wafer-to-wafer alignment accuracy essential. In this paper we investigate the effects of thermal and mechanical bonding parameters on the achievable post-bonding wafer-to-wafer alignment accuracy for polymer wafer bonding with 200 mm diameter wafers. Our baseline wafer bonding process with softbaked BCB (∼35% cross-linked) has been modified to use partially cured (∼ 43% crosslinked) BCB. The partially cured BCB layer does not reflow during bonding, minimizing the impact of inhomogeneities in BCB reflow under compression and/or slight shear forces at the bonding interface. As a result, the non-uniformity of the BCB layer thickness after wafer bonding is less than 0.5% of the nominal layer thickness and the wafer shift relative to each other during the wafer bonding process is less than 1 μm (average) for 200 mm diameter wafers. The critical adhesion energy of a bonded wafer pair with the partially cured BCB wafer bonding process is similar to that with soft-baked BCB.
The critical adhesion energy of benzocyclobutene (BCB)-bonded wafers is
quantitatively investigated with focus on BCB thickness, material stack and
thermal cycling. The critical adhesion energy depends linearly on BCB
thickness, increasing from 19 J/m2 to 31 J/m2 as the
BCB thickness increases from 0.4 μm to 2.6 μm, when bonding silicon wafers
coated with plasma enhanced chemical vapor deposited (PECVD) silicon dioxide
(SiO2). In thermal cycling performed with 350 and 400 oC peak temperatures,
the significant increase in critical adhesion energy at the interface
between BCB and PECVD SiO2 during the first thermal cycle is
attributed to relaxation of residual stress in the PECVD SiO2
layer. On the other hand, the critical adhesion energy at the interface
between BCB and PECVD silicon nitride (SiNx) decreases due to the
increase of residual stress in the PECVD SiNx layer during the
first thermal cycle.