4,156 research outputs found
Multispin Ising spin glasses with ferromagnetic interactions
We consider the thermodynamics of an infinite-range Ising p-spin glass model
with an additional r-spin ferromagnetic interaction. For r=2 there is a
continuous transition to a ferromagnetic phase, while for r>2 the transition is
first order. We find both glassy and non-glassy ferromagnetic phases, with
replica symmetry breaking of both the one step and full varieties. We obtain
new results for the case where r=p>2, demonstrating the existence of a
non-glassy ferromagnetic phase, of significance to error-correcting codes.Comment: 16 pages, AMS LaTeX, 14 EPS figures; one minor correction to (42
Expression and clinical relevance of SOX9 in gastric cancer
Gastric cancer is one of the most frequent tumours and the third leading cause of cancer-related death worldwide. The investigation of new biomarkers that can predict patient outcome more accurately and allow better treatment and follow-up decisions is of crucial importance. SOX9 (sex-determining region Y (SRY)-box 9) is a regulator of cell fate decisions in embryogenesis and adulthood. Here, we sought to ascertain the relevance of SOX9 transcription factor as a prognostic marker in gastric cancer. SOX9 expression was analyzed by immunohistochemistry in 333 gastric adenocarcinoma cases, and its association with clinicopathological and follow-up data was evaluated. SOX9 nuclear expression was absent in 17% of gastric cancer cases and predicted worse disease-free survival (P = 0 03). SOX9 expression was associated with lower risk of relapse in Cox univariable analysis (HR = 0 58; 95% CI = 0 35-0.97; P = 0 04). The prognostic value of SOX9 was more pronounced in tumours with expansive growth (P = 0 01) or with venous invasion (P = 0 02). Two validation cohorts from the Cancer Genome Atlas (TCGA) and the Asian Cancer Research Group (ACRG) confirmed that low SOX9 expression was significantly associated with poor patient outcome. In conclusion, we have identified SOX9 as a biomarker of disease relapse in gastric cancer patients. Further experiments are needed to elucidate its biological relevance at the cellular level.The authors wish to acknowledge the tumour and tissue bank at Hospital de São João for providing all the means to collect the human tissue samples included in this study. This work was supported by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020—Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT—Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Inovação in the framework of the project “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274). This work was also financed by the projects NORTE-01-0145-FEDER-000003 (DOCnet) and NORTE-07-0124-FEDER-000029 supported by Norte Portugal Regional Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). BP and RB acknowledge FCT for financial support (grants SFRH/BPD/109794/2015 and SFRH/BPD/68276/2010, respectively)
Paleomagnetic recording fidelity of nonideal magnetic systems
We carry out simple analytical calculations and Monte Carlo studies to better
understand the impact of QCD radiation on some well-known jet substructure
methods for jets arising from the decay of boosted Higgs bosons. Understanding
differences between taggers for these signal jets assumes particular
significance in situations where they perform similarly on QCD background jets.
As an explicit example of this we compare the Y-splitter method to the more
recently proposed Y-pruning technique. We demonstrate how the insight we gain
can be used to significantly improve the performance of Y-splitter by combining
it with trimming and show that this combination outperforms the other taggers
studied here, at high . We also make analytical estimates for optimal
parameter values, for a range of methods and compare to results from Monte
Carlo studies.Comment: 53 pages, 21 figures. Version published in JHEP: addressed several
points raised by the refere
Density Functional Molecular Study on the Full Conformational Space of the S-4-(2-Hydroxypropoxy)carbazol Fragment of Carvedilol (1-(9H−Carbazol-4-yloxy)-3- [2-(2-methoxyphenoxy)ethylamino]-2-propanol) in Vacuum and in Different Solvent Media
Density functional theory (DFT) conformational analysis was carried out
on the potential energy hypersurface (PEHS) of the carbazole-containing
molecular fragment, S-4-(2-hydroxypropoxy)-carbazol, of the chiral
cardiovascular drug molecule carvedilol,
(1-(9H-carbazol-4-yloxy)-3-[2-(2-methoxy-phenoxy)ethylamino]-2-propanol)
. The PEHS was computed in vacuum, chloroform, ethanol, DMSO, and water
at the B3LYP/6-31G(d) level of theory. The carbazole ring system was
confirmed to be planar, and the resultant PEHS in vacuum contained 19
converged minima, of which the global minima possessed a conformation
with chi(1), chi(2), and chi(3) in the anti position and chi(10) in the
g position. Conformer stability for the S-4-(2-hydroxypropoxy)carbazol
PEHS was influenced by intramolecular hydrogen bonding. Tomasi PCM
reaction-field calculations revealed that the lowest SCF energies,
relative conformer energies, and solvation free energies (DeltaG
(solvation)) for the S-4-(2-hydroxypropoxy)carbazol PEHS were in protic
solvents, ethanol and water, because of the larger hydrogen bond donor
values of these solvents, which aid in stabilization of the dipole
moment created by the carbazole ring system and the oxygen and nitrogen
atoms. However, solvent effects contributed most significantly to the
stabilization of S-4-(2-hydroxypropoxy)carbazol conformers that
contained no internal hydrogen bonding, whereas solvent effects were
not as important for conformers that contained intramolecular hydrogen
bonding
Left ventricular systolic dysfunction in Marfan syndrome is related to aortic distensibility
Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2019.Background: The cardiovascular involvement in Marfan syndrome (MS) is characterized mainly by dilatation and reduced distensibility of the ascending aorta. Left ventricular (LV) dysfunction has been detected in MS and a primary cardiomyopathy has been suggested but the pathophysiology is unclear. The purpose of this study was to evaluate the LV function in patients with MS and to assess the relationship with the aortic distensibility, as possible underlying mechanism. Methods: We studied 53 patients with MS (27.0 ± 11 years, 29 men) without valvular or hypertensive heart disease and a control group of 26 healthy subjects (29 ± 9 years, 17 men). All underwent echocardiography and cardiac magnetic resonance (CMR) and the following indexes were analyzed: a) Echo: mitral flow velocities E/A ratio and deceleration of mitral E; E’ velocity obtained from the medial and lateral mitral ring; E/E’ ratio b) CMR: LV volumes indexed to BSA and ejection fraction (EF); global longitudinal strain (GLS, Circle cvI42); maximal size and distensibility of proximal ascending aorta. Distensibility was calculated from maximal (systolic) and minimum (diastolic) area of maximal proximal ascending aorta (cross-sectional images from SSFP sequence) using the formula=(maximum area-minimum area)/[ minimum area x (systolic BP-diastolic BP)]. Results: 17 from 53 patients with MS had increased LV end-diastolic volume, 14 decreased EF (<50%) and 22 decreased GLS. Compared with the control group, patients with MS showed increased LV end-diastolic volume (85.0 ± 5.2vs 80.1 ± 5.3ml/m2, p = 0.04), lower GLS (17.1 ± 1.9 vs 18.9 ± 2.2, p = 0.01) lower LVEF (53.0 ± 7.1% vs 56.0 ± 5.4%, p = 0.03) and higher E/E’ value (9.2 ± 1.3 vs. 6.2 ± 0.8, p = 0.01) as well as larger dimensions of proximal aorta (39 ± 2.2cm vs 32 ± 0.8,p = 0.010) and lower aortic distensibility (3.4 ± 1.9 vs. 4.4 ± 1.7 dynes cm-1, p = 0.03). In the group of patients, a correlation was found between the aortic distensibility and the LVEF (r = 0.47, p = 0.045) and GLS (r = 0.65, p = 0.02), but not with the other variables. Aortic distensibility was an independent predictor of LV dysfunction using a cutoff of 50% for LVEF and 19% for GLS. Conclusion: In our population of patients with MS, we found changes in the LV function, which were related with aortic distensibility, possibly sharing a common pathway. The prognostic significance of these findings is under evaluation.info:eu-repo/semantics/publishedVersio
Paleomagnetic recording fidelity of nonideal magnetic systems
A suite of near-identical magnetite nanodot samples produced by electron-beam lithography have been used to test the thermomagnetic recording fidelity of particles in the 74–333 nm size range; the grain size range most commonly found in rocks. In addition to controlled grain size, the samples had identical particle spacings, meaning that intergrain magnetostatic interactions could be controlled. Their magnetic hysteresis parameters were indicative of particles thought not to be ideal magnetic recorders; however, the samples were found to be excellent thermomagnetic recorders of the magnetic field direction. They were also found to be relatively good recorders of the field intensity in a standard paleointensity experiment. The samples' intensities were all within ∼15% of the expected answer and the mean of the samples within 3% of the actual field. These nonideal magnetic systems have been shown to be reliable records of the geomagnetic field in terms of both direction and intensity even though their magnetic hysteresis characteristics indicate less than ideal magnetic grains
The role of transoral robotic surgery, transoral laser microsurgery, and lingual tonsillectomy in the identification of head and neck squamous cell carcinoma of unknown primary origin: a systematic review
Effect of an extract of Centella asiatica on the biodistribution of sodium pertechnetate (Na<sup>99m</sup>TcO<sub>4</sub>) and on the fixation of radioactivity on blood constituents
This study evaluates the effects of an acute treatment with a Centella asiatica (CA) extract on the biodistribution of the radiopharmaceutical Na99mTcO4 and on the fixation of technetium-99m on blood constituents. Wistar rats were treated with CA extract and, 1 hour after, Na99mTcO4 was administered; organs/tissues were withdrawn and weighted. The radioactivity was counted to calculate the percentage of activity per gram (%ATI/g). Also, blood samples were withdrawn, plasma (P), blood cells (BC), insoluble fraction (IF) and soluble fractions of P and BC were isolated and the radioactivity was counted to calculate the percentage of activity (%ATI). Data indicated that the acute treatment with CA extract changed significantly (p99mTcO4 and the fixation of the technetium-99m on blood constituents in an acute treatment
Competition between glassiness and order in a multi-spin glass
A mean-field multi-spin interaction spin glass model is analyzed in the
presence of a ferromagnetic coupling. The static and dynamical phase diagrams
contain four phases (paramagnet, spin glass, ordinary ferromagnet and glassy
ferromagnet) and exhibit reentrant behavior. The glassy ferromagnet phase has
anomalous dynamical properties. The results are consistent with a
nonequilibrium thermodynamics that has been proposed for glasses.Comment: revised version, 4 pages Revtex, 2 eps-figures. Phys. Rev. E, Rapid
Communication, to appea
- …