Late gadolinium enhancement cardiovascular magnetic resonance predicts clinical worsening in patients with pulmonary hypertension

<p>Abstract</p> <p>Background</p> <p>Late gadolinium enhancement (LGE) occurs at the right ventricular (RV) insertion point (RVIP) in patients with pulmonary hypertension (PH) and has been shown to correlate with cardiovascular magnetic resonance (CMR) derived RV indices. However, the prognostic role of RVIP-LGE and other CMR-derived parameters of RV function are not well established. Our aim was to evaluate the predictive value of contrast-enhanced CMR in patients with PH.</p> <p>Methods</p> <p>RV size, ejection fraction (RVEF), and the presence of RVIP-LGE were determined in 58 patients with PH referred for CMR. All patients underwent right heart catheterization, exercise testing, and N-terminal pro-brain natriuretic peptide (NT-proBNP) evaluation; results of which were included in the final analysis if performed within 4 months of the CMR study. Patients were followed for the primary endpoint of time to clinical worsening (death, decompensated right ventricular heart failure, initiation of prostacyclin, or lung transplantation).</p> <p>Results</p> <p>Overall, 40/58 (69%) of patients had RVIP-LGE. Patients with RVIP- LGE had larger right ventricular volume index, lower RVEF, and higher mean pulmonary artery pressure (mPAP), all p < 0.05. During the follow-up period of 10.2 ± 6.3 months, 19 patients reached the primary endpoint. In a univariate analysis, RVIP-LGE was a predictor for adverse outcomes (p = 0.026). In a multivariate analysis, CMR-derived RVEF was an independent predictor of clinical worsening (p = 0.036) along with well-established prognostic parameters such as exercise capacity (p = 0.010) and mPAP (p = 0.001).</p> <p>Conclusions</p> <p>The presence of RVIP-LGE in patients with PH is a marker for more advanced disease and poor prognosis. In addition, this study reveals for the first time that CMR-derived RVEF is an independent non-invasive imaging predictor of adverse outcomes in this patient population.</p

Schottky-based band lineups for refractory semiconductors

An overview is presented of band alignments for small-lattice parameter, refractory semiconductors. The band alignments are estimated empirically through the use of available Schottky barrier height data, and are compared to theoretically predicted values. Results for tetrahedrally bonded semiconductors with lattice constant values in the range from C through ZnSe are presented. Based on the estimated band alignments and the recently demonstrated p-type dopability of GaN, we propose three novel heterojunction schemes which seek to address inherent difficulties in doping or electrical contact to wide-gap semiconductors such as ZnO, ZnSe, and ZnS

Towards a grapho-phonologically parsed corpus of medieval Scots:Database design and technical solutions

This paper presents a newly constructed corpus of sound-to-spelling mappings in medieval Scots, which stems from the work of the From Inglis to Scots (FITS) project. We have developed a systematic approach to the relationships between individual spellings and proposed sound values, and recorded these mutual links in a relational database. In this paper, we introduce the theoretical underpinnings of sound-to-spelling and spelling-to-sound mappings, and show how a Scots root morpheme undergoes grapho-phonological parsing, the analytical procedure that is employed to break down spelling sequences into sound units. We explain the data collection and annotation for the FITS Corpus (Alcorn et al., forthcoming), drawing attention to the extensive meta-data which accompany each analysed unit of spelling and sound. The database records grammatical and lexical information about the root, the positional arrangement of segments within the root, labels for the nuclei, vowels and consonants, the morphological context, and extra-linguistic detail of the text a given root was taken from (date, place and text type). With this wealth of information, the FITS corpus is capable of answering complex queries about the sound and spelling systems of medieval Scots. We also suggest how our methodology can be transferred to other non-standardised spelling systems

Radiation management and credentialing of fluoroscopy users

During the last 15 years, developments in X-ray technologies have substantially improved the ability of practitioners to treat patients using fluoroscopically guided interventional techniques. Many of these procedures require a greater use of fluoroscopy and more recording of images. This increases the potential for radiation-induced dermatitis and epilation, as well as severe radiation-induced burns to patients. Many fluoroscope operators are untrained in radiation management and do not realize that these procedures increase the risk of radiation injury and radiation-induced cancer in personnel as well as patients. The hands of long-time fluoroscope operators in some cases exhibit radiation damage—especially when sound radiation protection practices have not been followed. In response, the Center for Devices and Radiological Health of the United States Food and Drug Administration has issued an Advisory calling for proper training of operators. Hospitals and administrators need to support and enforce the need for this training by requiring documentation of credentials in radiation management as a prerequisite for obtaining fluoroscopy privileges. A concerted effort on the part of professional medical organizations and regulatory agencies will be required to train fluoroscopy users to prevent physicians from unwittingly imparting serious radiation injuries to their patients

Comparing aerosol number and mass exhalation rates from children and adults during breathing, speaking and singing

Aerosol particles of respirable size are exhaled when individuals breathe, speak and sing and can transmit respiratory pathogens between infected and susceptible individuals. The COVID-19 pandemic has brought into focus the need to improve the quantification of the particle number and mass exhalation rates as one route to provide estimates of viral shedding and the potential risk of transmission of viruses. Most previous studies have reported the number and mass concentrations of aerosol particles in an exhaled plume. We provide a robust assessment of the absolute particle number and mass exhalation rates from measurements of minute ventilation using a non-invasive Vyntus Hans Rudolf mask kit with straps housing a rotating vane spirometer along with measurements of the exhaled particle number concentrations and size distributions. Specifically, we report comparisons of the number and mass exhalation rates for children (12–14 years old) and adults (19–72 years old) when breathing, speaking and singing, which indicate that child and adult cohorts generate similar amounts of aerosol when performing the same activity. Mass exhalation rates are typically 0.002–0.02 ng s(−1) from breathing, 0.07–0.2 ng s(−1) from speaking (at 70–80 dBA) and 0.1–0.7 ng s(−1) from singing (at 70–80 dBA). The aerosol exhalation rate increases with increasing sound volume for both children and adults when both speaking and singing

Age-related decline in associative learning in healthy Chinese adults

10.1371/journal.pone.0080648PLoS ONE811-POLN

General framework for fluctuating dynamic density functional theory

We introduce a versatile bottom-up derivation of a formal theoretical framework to describe (passive) soft-matter systems out of equilibrium subject to fluctuations. We provide a unique connection between the constituent-particle dynamics of real systems and the time evolution equation of their measurable (coarse-grained) quantities, such as local density and velocity. The starting point is the full Hamiltonian description of a system of colloidal particles immersed in a fluid of identical bath particles. Then, we average out the bath via Zwanzig's projection-operator techniques and obtain the stochastic Langevin equations governing the colloidal-particle dynamics. Introducing the appropriate definition of the local number and momentum density fields yields a generalisation of the Dean-Kawasaki (DK) model, which resembles the stochastic Navier-Stokes (NS) description of a fluid. Nevertheless, the DK equation still contains all the microscopic information and, for that reason, does not represent the dynamical law of observable quantities. We address this controversial feature of the DK description by carrying out a nonequilibrium ensemble average. Adopting a natural decomposition into local-equilibrium and nonequilibrium contribution, where the former is related to a generalised version of the canonical distribution, we finally obtain the fluctuating-hydrodynamic equation governing the time-evolution of the mesoscopic density and momentum fields. Along the way, we outline the connection between the ad-hoc energy functional introduced in previous DK derivations and the free-energy functional from classical density-functional theory (DFT). The resultant equation has the structure of a dynamical DFT (DDFT) with an additional fluctuating force coming from the random interactions with the bath. We show that our fluctuating DDFT formalism corresponds to a particular version of the fluctuating NS equations, originally derived by Landau and Lifshitz. Our framework thus provides the formal apparatus for ab-initio derivations of fluctuating DDFT equations capable of describing the dynamics of soft-matter systems in and out of equilibrium. We believe that the derivation offered here represents the current state of the art in the field

School closures during the 2009 influenza pandemic: national and local experiences

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