1,065 research outputs found
Cardiac Resynchronization Therapy in the Cardiorenal Syndrome
The cardiorenal syndrome (CRS) is a complex clinical syndrome in which dysfunction of either the heart or the kidneys affects the functioning of the other organ system. Many therapies used in heart failure have further detrimental effects on renal function. Cardiac resynchronization therapy (CRT) is a relatively new form of device therapy that reduces morbidity and mortality in patients with heart failure. This review will discuss the effects of CRT on renal function in patients with CRS, the impact of baseline renal function on response to CRT, and potential risks associated with CRT in this unique population
Size-dependent melting point depression of nickel nanoparticles
We investigate the phase-transition behaviour of nickel nanoparticles (3–6 nm) via dynamic TEM. The nanoparticles were synthesized within a reverse microemulsion and then monitored via dynamic TEM simultaneously while undergoing controlled heating. The size-dependent melting point depression experimentally observed is compared with, and is in good agreement with existing thermodynamic and molecular dynamic predictions
Optimism and Pessimism in Children with Cancer and Healthy Children: Confirmatory Factor Analysis of the Youth Life Orientation Test and Relations with Health-Related Quality of Life
Objective To test the measurement equivalence of the Youth Life Orientation Test (YLOT) in children with cancer (N = 199) and healthy controls (N = 108), and to examine optimism and pessimism as predictors of children\u27s health-related quality of life (HRQL).
Methods Confirmatory factor analysis (CFA) was conducted to establish the two factor structure of the YLOT and to test for metric invariance.
Results A two-factor structure for the YLOT was confirmed and found to be stable across our study groups. There were no differences in mean levels of optimism and pessimism between cancer patients and controls after controlling for race/ethnicity. Higher optimism was associated with lower self-reports of pain and better emotional/behavioral functioning, whereas pessimism was related to poorer mental health and general behavior, and greater impact on the family.
Conclusions Optimism and pessimism appear to be differentially related to certain aspects of children\u27s HRQL, and should be investigated separately in relation to these outcomes
The Cool Accretion Disk in ESO 243-49 HLX-1: Further Evidence of an Intermediate Mass Black Hole
With an inferred bolometric luminosity exceeding 10^42 erg/s, HLX-1 in ESO
243-49 is the most luminous of ultraluminous X-ray sources and provides one of
the strongest cases for the existence of intermediate mass black holes. We
obtain good fits to disk-dominated observations of the source with BHSPEC, a
fully relativistic black hole accretion disk spectral model. Due to
degeneracies in the model arising from the lack of independent constraints on
inclination and black hole spin, there is a factor of 100 uncertainty in the
best-fit black hole mass M. Nevertheless, spectral fitting of XMM-Newton
observations provides robust lower and upper limits with 3000 Msun < M < 3 x
10^5 Msun, at 90% confidence, placing HLX-1 firmly in the intermediate-mass
regime. The lower bound on M is entirely determined by matching the shape and
peak energy of the thermal component in the spectrum. This bound is consistent
with (but independent of) arguments based solely on the Eddington limit. Joint
spectral modelling of the XMM-Newton data with more luminous Swift and Chandra
observations increases the lower bound to 6000 Msun, but this tighter
constraint is not independent of the Eddington limit. The upper bound on M is
sensitive to the maximum allowed inclination i, and is reduced to M < 10^5 Msun
if we limit i < 75 deg.Comment: 10 pages, 7 figures, accepted for publication in Ap
Identification of integrative and conjugative elements in pathogenic and commensal Neisseriaceae spp. via genomic distributions of DNA uptake sequence dialects
Mobile genetic elements (MGEs) are key factors responsible for dissemination of virulence determinants and antimicrobial-resistance genes amongst pathogenic bacteria. Conjugative MGEs are notable for their high gene loads donated per transfer event, broad host ranges and phylogenetic ubiquity amongst prokaryotes, with the subclass of chromosomally inserted integrative and conjugative elements (ICEs) being particularly abundant. The focus on a small number of model systems has biased the study of ICEs towards those conferring readily selectable phenotypes to host cells, whereas the identification and characterization of integrated cryptic elements remains challenging. Even though antimicrobial resistance and horizontally acquired virulence genes are major factors aggravating neisserial infection, conjugative MGEs of Neisseria gonorrhoeae and Neisseria meningitidis remain poorly characterized. Using a phenotype-independent approach based on atypical distributions of DNA uptake sequences (DUSs) in MGEs relative to the chromosomal background, we have identified two groups of chromosomally integrated conjugative elements in Neisseria: one found almost exclusively in pathogenic species possibly deriving from the genus Kingella, the other belonging to a group of Neisseria mucosa-like commensals. The former element appears to enable transfer of traditionally gonococcal-specific loci such as the virulence-associated toxin–antitoxin system fitAB to N. meningitidis chromosomes, whilst the circular form of the latter possesses a unique attachment site (attP) sequence seemingly adapted to exploit DUS motifs as chromosomal integration sites. In addition to validating the use of DUS distributions in Neisseriaceae MGE identification, the >170 identified ICE sequences provide a valuable resource for future studies of ICE evolution and host adaptation
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