2,427 research outputs found
Instanton Effects in QCD Sum Rules for the Hybrid
In this paper, we study instanton contributions to the correlator of the
hybrid current . These contributions
are then included in a QCD sum-rule analysis of the isoscalar hybrid
mass. We find a mass at 1.83 GeV for the hybrid.
However, for the hybrid, we find the sum rules are unstable. We also
study non-zero width effects, which affect the mass prediction. The mixing
effects between these two states are studied and we find QCD sum rules support
the existence of a flavor singlet hybrid with mass at around 1.9 GeV. Finally,
we study the mixing effects between hybrid and glueball currents. The mixing
between the () and the glueball causes
two states, one in the region 1.4-1.8 GeV(1.4-2.2 GeV), and the other in the
range 1.8-2.2 GeV(2.2-2.6 GeV).Comment: 12 pages, revised versio
Decreased density of serotonin 2A receptors in the superior temporal gyrus in schizophrenia - a postmortem study
The superior temporal gyrus (STG) is strongly implicated in the pathophysiology of schizophrenia,particularly with regards to auditory hallucinations. In this study, using in situ quantitative autoradiography in postmortem tissue, we investigated the binding of the [3H]ketanserin to 5-HT2A receptors and [3H] mesulergine to 5-HT2C receptors in the left STG of 8 male schizophrenic patients compared to 8 control subjects. A strong [3H]ketanserin binding was observed in the STG, however there was a very weak [3H] mesulergine binding in the STG. A significant decrease in binding of [3H]ketanserin was clearly observed in schizophrenia patients in comparison with control subjects. There were no significant correlations between 5-HT2A binding density and age, postmortem intervals, or brain pH. These results suggest that the alterations of the 5-HT2A receptors contribute to the pathophysiology of the STG in schizophrenia. Furthermore, there is a clear tendency for a positive correlation between 5-HT2A and muscarinic M1 receptor bindings, and for negative correlations between 5-HT2A and GABAA receptor bindings and between muscarinic M1 and GABAA receptor bindings. This provides a possible mechanism of auditory hallucinations through interactions between 5-HT2A, acetylcholine muscarinic and GABA transmissions in the STG in schizophrenia
A Hot Spots Ignition Probability Model for Low-Velocity Impacted Explosive Particles Based on the Particle Size and Distribution
Possible Way to Synthesize Superheavy Element Z=117
Within the framework of the dinuclear system model, the production of
superheavy element Z=117 in possible projectile-target combinations is analyzed
systematically. The calculated results show that the production cross sections
are strongly dependent on the reaction systems. Optimal combinations,
corresponding excitation energies and evaporation channels are proposed in this
letter, such as the isotopes ^{248,249}Bk in ^{48}Ca induced reactions in 3n
evaporation channels and the reactions ^{45}Sc+^{246,248}Cm in 3n and 4n
channels, and the system ^{51}V+^{244}Pu in 3n channel.Comment: 10 pages, 4 figures, 1 tabl
Plasma MicroRNA-29c Levels Are Associated with Carotid Intima-Media Thickness and is a Potential Biomarker for the Early Detection of Atherosclerosis
Background/Aims: Atherosclerosis is a serious disease that increases the risk of myocardial infarction and ischemic stroke. Previous studies have demonstrated that microRNA (miR)-29c could play significant roles in atherosclerosis via regulating inflammatory processes. However, the relationship between miR-29c and carotid intima-media thickness (CIMT) remains unknown. This study investigated associations between miR-29c and atherosclerosis and tested whether plasma miR-29c levels could be used to detect atherosclerosis. Methods: Plasma miR-29c levels were estimated by quantitative real-time PCR, and CIMT was measured by carotid ultrasound. Associations between miR-29c and CIMT were assessed by Spearman’s correlation coefficient and multiple linear regression analyses. Results: In total, 170 participants were divided into the study (CIMT ≥0.9 mm) and control (CIMT < 0.9 mm) groups. The study group showed higher C-reactive protein (CRP) and miR-29c relative expression levels compared with the control group. CIMT was positively correlated with miR-29c (r=0.659, p< 0.001) and CRP (r=0.447, p< 0.001), and miR-29c levels were also correlated with CRP (r=0.512, p< 0.001). Furthermore, multiple linear regression analysis showed that CIMT was significantly correlated with miR-29c (β=0.573, 95% confidence interval [CI]: 0.315-0.839; p< 0.001) and CRP (β=0.439, 95%CI: 0.186–0.825; p< 0.001). After age, body mass index, systolic blood pressure, total cholesterol and fasting blood-glucose were adjusted for, CIMT was still closely associated with miR-29c (β=0.529, 95%CI: 0.354–0.812; p< 0.001) and CRP (β=0.417, 95%CI: 0.198–0.724; p< 0.001). Evaluating CRP and miR-29c together (AUC=0.900, p< 0.001) achieved a better prognostic value for atherosclerosis than miR-29c (AUC=0.870, p< 0.001) or CRP (AUC=0.722, p< 0.001) alone. Conclusion: Increased miR-29c was closely associated with CIMT and may serve as a biomarker for identifying atherosclerotic patients
Editorial: Sustainable biorefinery/bioprocessing design for functional ingredient production from food waste and byproducts
Damage and Failure Process of Concrete Structure under Uniaxial Compression Based on Peridynamics Modeling
Peridynamics is a nonlocal formulation of continuum mechanics, which uses integral formulation rather than the spatial partial differential equations. The peridynamic approach avoids using any spatial derivatives, which arise naturally in the classical local theory. It has shown effectiveness and advantage in solving discontinuous problems at both macro- and microscales. In this paper, the peridynamic theory is used to analyze damage and progressive failure of concrete structures. A nonlocal peridynamic model for concrete columns under uniaxial compression is developed. Numerical example illustrates that cracks in a peridynamic body of concrete form spontaneously. The result of the example clarifies the unique advantage of modeling damage accumulation and progressive failure of concrete based on peridynamic theory. This study provides a new promising alternative for analyzing complicated discontinuity problems. Finally, some open problems and future research trends in peridynamics are discussed
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