164 research outputs found
Effect of orthopedic and functional orthodontic treatment in children with obstructive sleep apnea: A systematic review and meta-analysis
Orthodontic treatment is suggested in growing individuals to correct transverse maxillary deficiency and mandibular retrusion. Since, as a secondary effect, these orthodontic procedures may improve pediatric obstructive sleep apnea (OSA), this systematic review assessed their effects on apnea-hypopnea index (AHI) and oxygen saturation (SaO2). Twenty-five (25) manuscripts were included for qualitative synthesis, 19 were selected for quantitative synthesis. Five interventions were analyzed: rapid maxillary expansion (RME, 15 studies), mandibular advancement (MAA, five studies), myofunctional therapy (MT, four studies), and RME combined with MAA (one study). RME produced a significant AHI reduction and minimum SaO2 increase immediately after active treatment, at six and 12 months from baseline. A significant AHI reduction was also observed six and 12 months after the beginning of MAA treatment. MT showed positive effects, with different protocols. In this systematic review and meta-analysis of data from mainly uncontrolled studies, interceptive orthodontic treatments showed overall favorable effects on respiratory outcomes in pediatric OSA. However, due to the low to very low level of the body evidence, this treatment cannot be suggested as elective for OSA treatment. An orthodontic indication is needed to support this therapy and a careful monitoring is required to ensure positive improvement in OSA parameters
Imaging biomarkers in prostate cancer: role of PET/CT and MRI
Prostate-specific antigen (PSA) is currently the most widely used biomarker of prostate cancer (PCa). PSA suggests the presence of primary tumour and disease relapse after treatment, but it is not able to provide a clear distinction between locoregional and distant disease. Molecular and functional imaging, that are able to provide a detailed and comprehensive overview of PCa extension, are more reliable tools for primary tumour detection and disease extension assessment both in staging and restaging. In the present review we evaluate the role of PET/CT and MRI in the diagnosis, staging and restaging of PCa, and the use of these imaging modalities in prognosis, treatment planning and response assessment. Innovative imaging strategies including new radiotracers and hybrid scanners such as PET/MRI are also discussed
Extracellular DNA secreted in yeast cultures is metabolism-specific and inhibits cell proliferation
Extracellular DNA (exDNA) can be actively released by living cells and different putative functions have been attributed to it. Further, homolo-gous exDNA has been reported to exert species-specific inhibitory effects on several organisms. Here, we demonstrate by different experimental evidence, including 1H-NMR metabolomic fingerprint, that the growth rate decline in Saccharomyces cerevisiae fed-batch cultures is determined by the accumula-tion of exDNA in the medium. Sequencing of such secreted exDNA represents a portion of the entire genome, showing a great similarity with extrachromo-somal circular DNA (eccDNA) already reported inside yeast cells. The recov-ered DNA molecules were mostly single strands and specifically associated to the yeast metabolism displayed during cell growth. Flow cytometric analysis showed that the observed growth inhibition by exDNA corresponded to an arrest in the S phase of the cell cycle. These unprecedented findings open a new scenario on the functional role of exDNA produced by living cells
Precision Determination of the Neutron Spin Structure Function g1n
We report on a precision measurement of the neutron spin structure function
using deep inelastic scattering of polarized electrons by polarized
^3He. For the kinematic range 0.014<x<0.7 and 1 (GeV/c)^2< Q^2< 17 (GeV/c)^2,
we obtain at an average . We find relatively large negative
values for at low . The results call into question the usual Regge
theory method for extrapolating to x=0 to find the full neutron integral
, needed for testing quark-parton model and QCD sum rules.Comment: 5 pages, 3 figures To be published in Phys. Rev. Let
Q^2 Evolution of the Neutron Spin Structure Moments using a He-3 Target
We have measured the spin structure functions and of He in a
double-spin experiment by inclusively scattering polarized electrons at
energies ranging from 0.862 to 5.07 GeV off a polarized He target at a
15.5 scattering angle. Excitation energies covered the resonance and
the onset of the deep inelastic regions. We have determined for the first time
the evolution of ,
and for the neutron in the range 0.1 GeV 0.9 GeV with good precision. displays a smooth
variation from high to low . The Burkhardt-Cottingham sum rule holds
within uncertainties and is non-zero over the measured range.Comment: 5 pages, 2 figures, submitted to Phys. Rev. Lett.. Updated Hermes
data in Fig. 2 (top panel) and their corresponding reference. Updated the low
x extrapolation error Fig. 2 (middle panel). Corrected references to ChiPT
calculation
Measurement of the Generalized Forward Spin Polarizabilities of the Neutron
The generalized forward spin polarizabilities and of
the neutron have been extracted for the first time in a range from 0.1 to
0.9 GeV. Since is sensitive to nucleon resonances and
is insensitive to the resonance, it is expected that the
pair of forward spin polarizabilities should provide benchmark tests of the
current understanding of the chiral dynamics of QCD. The new results on
show significant disagreement with Chiral Perturbation Theory
calculations, while the data for at low are in good agreement
with a next-to-lead order Relativistic Baryon Chiral Perturbation theory
calculation. The data show good agreement with the phenomenological MAID model.Comment: 5 pages, 2 figures, corrected typo in author name, published in PR
The Q^2 evolution of the generalized Gerasimov-Drell-Hearn integral for the neutron using a He-3 target
We present data on the inclusive scattering of polarized electrons from a
polarized He-3 target at energies from 0.862 to 5.06 GeV, obtained at a
scattering angle of 15.5 degrees. Our data include measurements from the
quasielastic peak, through the resonance region, to the beginning of the deep
inelastic regime, and were used to determine the spin difference in the virtual
photoabsorption cross section. We extract the extended Gerasimov-Drell-Hearn
integral for the neutron in the range of 4-momentum transfer squared Q^2 of
0.1-0.9 GeV.Comment: 14 pages of text when TeXed in preprint format with figures embedded.
RevTeX format. Three eps figure
Measurement of the Proton and Deuteron Spin Structure Functions g2 and Asymmetry A2
We have measured the spin structure functions g2p and g2d and the virtual
photon asymmetries A2p and A2d over the kinematic range 0.02 < x < 0.8 and 1.0
< Q^2 < 30(GeV/c)^2 by scattering 38.8 GeV longitudinally polarized electrons
from transversely polarized NH3 and 6LiD targets.The absolute value of A2 is
significantly smaller than the sqrt{R} positivity limit over the measured
range, while g2 is consistent with the twist-2 Wandzura-Wilczek calculation. We
obtain results for the twist-3 reduced matrix elements d2p, d2d and d2n. The
Burkhardt-Cottingham sum rule integral - int(g2(x)dx) is reported for the range
0.02 < x < 0.8.Comment: 12 pages, 4 figures, 1 tabl
Virtual Compton Scattering and the Generalized Polarizabilities of the Proton at Q^2=0.92 and 1.76 GeV^2
Virtual Compton Scattering (VCS) on the proton has been studied at Jefferson
Lab using the exclusive photon electroproduction reaction (e p --> e p gamma).
This paper gives a detailed account of the analysis which has led to the
determination of the structure functions P_LL-P_TT/epsilon and P_LT, and the
electric and magnetic generalized polarizabilities (GPs) alpha_E(Q^2) and
beta_M(Q^2) at values of the four-momentum transfer squared Q^2= 0.92 and 1.76
GeV^2. These data, together with the results of VCS experiments at lower
momenta, help building a coherent picture of the electric and magnetic GPs of
the proton over the full measured Q^2-range, and point to their non-trivial
behavior.Comment: version 2: modified according to PRC Editor's and Referee's
recommendations. Archival paper for the E93-050 experiment at JLab Hall A. 28
pages, 23 figures, 5 cross-section tables. To be submitted to Phys.Rev.
Measurements of the -Dependence of the Proton and Neutron Spin Structure Functions g1p and g1n
The structure functions g1p and g1n have been measured over the range 0.014 <
x < 0.9 and 1 < Q2 < 40 GeV2 using deep-inelastic scattering of 48 GeV
longitudinally polarized electrons from polarized protons and deuterons. We
find that the Q2 dependence of g1p (g1n) at fixed x is very similar to that of
the spin-averaged structure function F1p (F1n). From a NLO QCD fit to all
available data we find at
Q2=5 GeV2, in agreement with the Bjorken sum rule prediction of 0.182 \pm
0.005.Comment: 17 pages, 3 figures. Submitted to Physics Letters
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