24 research outputs found
The New Transverse-Facial Artery Musculomucosal Flap for Intraoral Reconstructions
With the bilateral progression of the 2 pedicled flaps, we were able to successfully restore both form and function of the soft palate, with a single-stage straightforward procedure, preserving at the same time the natural course of the facial arteries. Both flaps healed uneventfully. Six days after operation, the patient was placed on a liquid diet with no velopharyngeal insufficiency. This is to our knowledge the first extensive palatal reconstruction carried out with intraoral flaps onl
An Analysis of the Nazi Film Hitlerjunge Quex
<p>CTRL values are shown as mean±SE. Statistical significance level was defined as p<0.05.</p
Toward an accurate prediction of inter-residue distances in proteins using 2D recursive neural networks
BACKGROUND: Protein inter-residue contact maps provide a translation and rotation invariant topological representation of a protein. They can be used as an intermediary step in protein structure predictions. However, the prediction of contact maps represents an unbalanced problem as far fewer examples of contacts than non-contacts exist in a protein structure. In this study we explore the possibility of completely eliminating the unbalanced nature of the contact map prediction problem by predicting real-value distances between residues. Predicting full inter-residue distance maps and applying them in protein structure predictions has been relatively unexplored in the past. RESULTS: We initially demonstrate that the use of native-like distance maps is able to reproduce 3D structures almost identical to the targets, giving an average RMSD of 0.5Ă
. In addition, the corrupted physical maps with an introduced random error of ±6Ă
are able to reconstruct the targets within an average RMSD of 2Ă
. After demonstrating the reconstruction potential of distance maps, we develop two classes of predictors using two-dimensional recursive neural networks: an ab initio predictor that relies only on the protein sequence and evolutionary information, and a template-based predictor in which additional structural homology information is provided. We find that the ab initio predictor is able to reproduce distances with an RMSD of 6Ă
, regardless of the evolutionary content provided. Furthermore, we show that the template-based predictor exploits both sequence and structure information even in cases of dubious homology and outperforms the best template hit with a clear margin of up to 3.7Ă
. Lastly, we demonstrate the ability of the two predictors to reconstruct the CASP9 targets shorter than 200 residues producing the results similar to the state of the machine learning art approach implemented in the Distill server. CONCLUSIONS: The methodology presented here, if complemented by more complex reconstruction protocols, can represent a possible path to improve machine learning algorithms for 3D protein structure prediction. Moreover, it can be used as an intermediary step in protein structure predictions either on its own or complemented by NMR restraints
A closed-form formula characterization of the Epps effect
In this study we provide an analytical characterization of the impact of zero returns on the popular realized covariance estimator of Barndorff-Nielsen and Shephard [Econometric analysis of realized covariation: High frequency based covariance, regression, and correlation in financial economics. Econometrica, 2004, 72(3), 885â925]. In our framework, efficient price processes evolve as a semimartingale with some likelihood of repeated prices. We show that the standard realized covariance estimator is asymptotically affected by a downward bias, and the size of the bias depends on these likelihoods. We demonstrate that this result can be used to construct a consistent estimator of the integrated covariance of a vector semimartingale. The advantages with respect to other estimators are discussed with data
Solubilization and coordination of the HgCl2 molecule in water, methanol, acetone, and acetonitrile: an X-ray absorption investigation
X-ray absorption spectroscopy (XAS) has been employed to carry out structural characterization of the local environment around mercury after the dissolution of the HgCl2 molecule. A combined EXAFS (extended X-ray absorption fine structure) and XANES (X-ray absorption near edge structure) data analysis has been performed on the Hg L3-edge absorption spectra recorded on 0.1 M HgCl2 solutions in water, methanol (MeOH), acetone and acetonitrile. The Hg-Cl distance determined by EXAFS (2.29(2)-2.31(2) AÌ) is always comparable to that found in the HgCl2 crystal (2.31(2) AÌ), demonstrating that the HgCl2 molecule dissolves in these solvents without dissociating. A small sensitivity of EXAFS to the solvent molecules interacting with HgCl2 has been detected and indicates a high degree of configurational disorder associated with this contribution. XANES data analysis, which is less affected by the disorder, was therefore carried out for the first time on these systems to shed light into the still elusive structural arrangement of the solvent molecules around HgCl2. The obtained results show that, in aqueous and MeOH solutions, the XANES data are compatible with three solvent molecules arranged around the HgCl2 unit to form a trigonal bipyramidal structure. The determination of the three-body Cl-Hg-Cl distribution shows a certain degree of uncertainty around the average 180° bond angle value, suggesting that the HgCl2 molecule probably vibrates in the solution around a linear configuration
Individual regression for heart rate (HR) <i>vs</i> the corresponding for one ALL and one CTRL child (A graph).
<p>Regression between the individual slopes of the HR <i>vs </i> relationship, obtained in children with ALL (nâ=â10) and skeletal muscle O<sub>2</sub> extraction at peak of exercise Î[HHb]<sub>peak</sub>, expressed as the ratio of the values obtained during limb ischemia with the corresponding regression line (B graph). CTRL values are given as mean±SE. Statistical significance level was defined as p<0.05.</p
Individual and mean values of relative to predicted in ALL (nâ=â10) and CTRL (nâ=â10) children.
<p>Statistical significance level was defined as p<0.05.</p
Individual and mean values of body mass index percentile (BMI) in ALL (nâ=â10) and CTRL (nâ=â10) children.
<p>Statistical significance level was defined as p<0.05.</p
Mean±SD of basal and peak values (with coefficient of variation) of the investigated variables in the two groups of children.
<p><i>: O2 uptake; </i><i>: pulmonary ventilation; PetO2: pulmonary end tidal of O2; Pet CO2: pulmonary end tidal of CO2; Sa O2: arterial blood saturation; Î[HHb]: skeletal muscle O2 extraction.</i></p><p>* p<0.05 significantly different from CTRL peak values.</p
Structure Evolution of Ge-Doped CaTiO3 (CTG) at High Pressure: Search for the First 2:4 Locked-Tilt Perovskite by Synchrotron Xâray Diffraction and DFT Calculations
This research investigates the high-pressure behavior of the Ca(Ti0.95Ge0.05)O3 perovskite, a candidate of the locked-tilt perovskite family (orthorhombic compounds characterized by the absence of changes in the octahedral tilt and volume reduction under pressure controlled solely by isotropic compression). The study combines experimental high-pressure synchrotron diffraction data with density functional theory (DFT) calculations, complemented by the X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), to understand the structural evolution of the perovskite under pressure. The results show that CTG undergoes nearly isotropic compression with the same compressibility along all three unit-cell axes (i.e., Ka0 = Kb0 = Kc0, giving a normalized cell distortion factor with pressure dnorm(P) = 1). However, a modest increase in octahedral tilting with pressure is revealed by DFT calculations, qualifying CTG as a new type of GdFeO3-type perovskite that exhibits both isotropic compression and nonlocked tilting. This finding complements two existing types: perovskites with anisotropic compression and tilting changes and those with isotropic compression and locked tilting. The multimethod approach provides valuable insights into the structural evolution of locked-tilt perovskites under high pressure and establishes a protocol for the efficient study of complex high-pressure systems. The results have implications for the design of new functional materials with desirable properties