2,230 research outputs found
Correlation between head shape and volumetric changes following spring-assisted posterior vault expansion
OBJECTIVE:
To investigate whether different head shapes show different volumetric changes following spring-assisted posterior vault expansion (SA-PVE) and to investigate the influence of surgical and morphological parameters on SA-PVE.
MATERIALS AND METHODS:
Preoperative three-dimensional skull models from patients who underwent SA-PVE were extracted from computed tomography scans. Patient head shape was described using statistical shape modelling (SSM) and principal component analysis (PCA). Preoperative and postoperative intracranial volume (ICV) and cranial index (CI) were calculated. Surgical and morphological parameters included skull bone thickness, number of springs, duration of spring insertion and type of osteotomy.
RESULTS:
In the analysis, 31 patients were included. SA-PVE resulted in a significant ICV increase (284.1 ± 171.6 cm3, p<0.001) and a significant CI decrease (â2.9 ± 4.3%, p<0.001). The first principal component was significantly correlated with change in ICV (Spearman Ï = 0.68, p<0.001). Change in ICV was significantly correlated with skull bone thickness (Ï = â0.60, p<0.001) and age at time of surgery (Ï = â0.60, p<0.001). No correlations were found between the change in ICV and number of springs, duration of spring insertion and type of osteotomy.
CONCLUSION:
SA-PVE is effective for increasing the ICV and resolving raised intracranial pressure. Younger, brachycephalic patients benefit more from surgery in terms of ICV increase. Skull bone thickness seems to be a crucial factor and should be assessed to achieve optimal ICV increase. In contrast, insertion of more than two springs, duration of spring insertion or performing a fully cut through osteotomy do not seem to impact the ICV increase. When interpreting ICV increases, normal calvarial growth should be taken into account
A Cryogenic High-Reynolds Turbulence Experiment at CERN
The potential of cryogenic helium flows for studying high-Reynolds number turbulence in the laboratory has been recognised for a long time and implemented in several small-scale hydrodynamic experiments. With its large superconducting particle accelerators and detector magnets, CERN, the European Laboratory for Particle Physics, has become a major world center in helium cryogenics, with several large helium refrigerators having capacities up to 18 kW @ 4.5 K. Combining a small fraction of these resources with the expertise of three laboratories at the forefront of turbulence research, has led to the design, swift implementation, and successful operation of GReC (Grands Reynolds Cryogéniques) a large axisymmetric turbulent-jet experiment. With flow-rates up to 260 g/s of gaseous helium at ~ 5 K and atmospheric pressure, Reynolds numbers up to 107 have been achieved in a 4.6 m high, 1.4 m diameter cryostat. This paper presents the results of the first runs and describes the experimental set-up comprehensively equipped with "hot" wire micro-anemometers, acoustic scattering vorticity measurements and a large-bandwidth data acquisition system
Insights into metazoan evolution from <i>Alvinella pompejana</i> cDNAs
BackgroundAlvinella pompejana is a representative of Annelids, a key phylum for evo-devo studies that is still poorly studied at the sequence level. A. pompejana inhabits deep-sea hydrothermal vents and is currently known as one of the most thermotolerant Eukaryotes in marine environments, withstanding the largest known chemical and thermal ranges (from 5 to 105°C). This tube-dwelling worm forms dense colonies on the surface of hydrothermal chimneys and can withstand long periods of hypo/anoxia and long phases of exposure to hydrogen sulphides. A. pompejana specifically inhabits chimney walls of hydrothermal vents on the East Pacific Rise. To survive, Alvinella has developed numerous adaptations at the physiological and molecular levels, such as an increase in the thermostability of proteins and protein complexes. It represents an outstanding model organism for studying adaptation to harsh physicochemical conditions and for isolating stable macromolecules resistant to high temperatures.ResultsWe have constructed four full length enriched cDNA libraries to investigate the biology and evolution of this intriguing animal. Analysis of more than 75,000 high quality reads led to the identification of 15,858 transcripts and 9,221 putative protein sequences. Our annotation reveals a good coverage of most animal pathways and networks with a prevalence of transcripts involved in oxidative stress resistance, detoxification, anti-bacterial defence, and heat shock protection. Alvinella proteins seem to show a slow evolutionary rate and a higher similarity with proteins from Vertebrates compared to proteins from Arthropods or Nematodes. Their composition shows enrichment in positively charged amino acids that might contribute to their thermostability. The gene content of Alvinella reveals that an important pool of genes previously considered to be specific to Deuterostomes were in fact already present in the last common ancestor of the Bilaterian animals, but have been secondarily lost in model invertebrates. This pool is enriched in glycoproteins that play a key role in intercellular communication, hormonal regulation and immunity.ConclusionsOur study starts to unravel the gene content and sequence evolution of a deep-sea annelid, revealing key features in eukaryote adaptation to extreme environmental conditions and highlighting the proximity of Annelids and Vertebrates
Recommended from our members
Plasma-Enhanced Atomic Layer Deposition of Al<inf>2</inf>O<inf>3</inf> on Graphene Using Monolayer hBN as Interfacial Layer
Abstract: The deposition of dielectric materials on graphene is one of the bottlenecks for unlocking the potential of graphene in electronic applications. The plasma enhanced atomic layer deposition of 10 nm thin high quality aluminum oxide (Al2O3) on graphene is demonstrated using a monolayer of hexagonal boron nitride (hBN) as protection layer. Raman spectroscopy is performed to analyze possible structural changes of the graphene lattice caused by the plasma deposition. The results show that a monolayer of hBN in combination with an optimized deposition process can effectively protect graphene from damage, while significant damage is observed without an hBN layer. Electrical characterization of double gated graphene field effect devices confirms that the graphene does not degrade during the plasma deposition of Al2O3. The leakage current densities are consistently below 1 pA ”mâ2 for electric fields across the insulators of up to 8 MV cmâ1, with irreversible breakdown happening above. Such breakdown electric fields are typical for Al2O3 and can be seen as an indicator for high quality dielectric films
Practical management of Chronic Myeloid Leukemia in Belgium
peer reviewedImatinib has drastically changed the outcome of patients with chronic myeloid leukemia (CML), with the majority of them showing a normal life span. Recently, the development of second and third generation tyrosine kinase inhibitors (TKIs) and the possibility of treatment discontinuation made the management of these patients more challenging. In this review, practical management guidelines of CML are presented, adapted to the Belgian situation in 2014. In first line chronic phase patients, imatinib, nilotinib and dasatinib can be prescribed. While second generation TKIs give faster and deeper responses, their impact on long-term survival remain to be determined. The choice of the TKI depends on CML risk score, priority for a deep response to allow a treatment-free remission protocol, age, presence of comorbid conditions, side effect profile, drug interactions, compliance concerns and price. Monitoring the response has to be made according the 2013 ELN criteria, and is based on the bone-marrow cytogenetic response during the first months and on the blood molecular response. Molecular follow-up is sufficient in patients with a complete cytogenetic response. For patients who fail frontline therapy, nilotinib, dasatinib, bosutinib and ponatinib are an option depending of the type of intolerance or resistance. T315I patients are only sensitive to ponatinib, which has to be carefully handled due to cardiovascular toxicity. Advanced phase diseases are more difficult to handle, with treatments including allogeneic stem cell transplantation, which is also an option for patients failing at least two TKIs. The possibility of treatment-free remission and pregnancy are also discussed
Measurement of Ï c1 and Ï c2 production with sâ = 7 TeV pp collisions at ATLAS
The prompt and non-prompt production cross-sections for the Ï c1 and Ï c2 charmonium states are measured in pp collisions at sâ = 7 TeV with the ATLAS detector at the LHC using 4.5 fbâ1 of integrated luminosity. The Ï c states are reconstructed through the radiative decay Ï c â J/ÏÎł (with J/Ï â ÎŒ + ÎŒ â) where photons are reconstructed from Îł â e + e â conversions. The production rate of the Ï c2 state relative to the Ï c1 state is measured for prompt and non-prompt Ï c as a function of J/Ï transverse momentum. The prompt Ï c cross-sections are combined with existing measurements of prompt J/Ï production to derive the fraction of prompt J/Ï produced in feed-down from Ï c decays. The fractions of Ï c1 and Ï c2 produced in b-hadron decays are also measured
Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC
The uncertainty on the calorimeter energy response to jets of particles is
derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the
calorimeter response to single isolated charged hadrons is measured and
compared to the Monte Carlo simulation using proton-proton collisions at
centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009
and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter
response to specific types of particles (positively and negatively charged
pions, protons, and anti-protons) is measured and compared to the Monte Carlo
predictions. Finally, the jet energy scale uncertainty is determined by
propagating the response uncertainty for single charged and neutral particles
to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3%
for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table,
submitted to European Physical Journal
- âŠ