We consider the fidelity of the vector meson dominance (VMD) assumption as an instrument for relating the electromagnetic vector-meson production reaction
e
+
p
→
e
′
+
V
+
p
to the purely hadronic ...process
V
+
p
→
V
+
p
. Analyses of the photon vacuum polarisation and the photon-quark vertex reveal that such a VMD
Ansatz
might be reasonable for light vector-mesons. However, when the vector-mesons are described by momentum-dependent bound-state amplitudes, VMD fails for heavy vector-mesons: it cannot be used reliably to estimate either a photon-to-vector-meson transition strength or the momentum dependence of those integrands that would arise in calculations of the different reaction amplitudes. Consequently, for processes involving heavy mesons, the veracity of both cross-section estimates and conclusions based on the VMD assumption should be reviewed, e.g., those relating to hidden-charm pentaquark production and the origin of the proton mass.
The amyloid-β protein (Aβ) protein plays a pivotal role in the pathogenesis of Alzheimer's disease (AD). It is believed that Aβ deposited in the brain originates from the brain tissue itself. ...However, Aβ is generated in both brain and peripheral tissues. Whether circulating Aβ contributes to brain AD-type pathologies remains largely unknown. In this study, using a model of parabiosis between APPswe/PS1dE9 transgenic AD mice and their wild-type littermates, we observed that the human Aβ originated from transgenic AD model mice entered the circulation and accumulated in the brains of wild-type mice, and formed cerebral amyloid angiopathy and Aβ plaques after a 12-month period of parabiosis. AD-type pathologies related to the Aβ accumulation including tau hyperphosphorylation, neurodegeneration, neuroinflammation and microhemorrhage were found in the brains of the parabiotic wild-type mice. More importantly, hippocampal CA1 long-term potentiation was markedly impaired in parabiotic wild-type mice. To the best of our knowledge, our study is the first to reveal that blood-derived Aβ can enter the brain, form the Aβ-related pathologies and induce functional deficits of neurons. Our study provides novel insight into AD pathogenesis and provides evidence that supports the development of therapies for AD by targeting Aβ metabolism in both the brain and the periphery.
Summary
The receptor activator of nuclear factor-kappa B ligand (RANKL)/RANK/osteoprotegerin system is dysregulated in hyperparathyroid bone diseases. The introduction of denosumab preceding elective ...surgery as an alternative option when surgery is not possible immediately.
Introduction
The effects of denosumab on vascular calcification in patients with chronic renal failure and low bone mass have been a subject of interest. Therefore, this investigation aimed to determine the short-term changes in vascular calcification after denosumab treatment using a serial electrocardiography-gated computed tomography (CT) to measure coronary artery calcification (CAC) in patients with secondary hyperparathyroidism (SHPT) and low bone mass.
Methods
This 6-month study enrolled patients with SHPT and low bone mass (T-score < − 2.5) owing to dialysis. The 2 groups administered denosumab at a dose of 60 mg (denosumab group), and conventional treatment (control group) had 21 patients each. All patients underwent CT scans at baseline and at the follow-up examination at 6 months to determine the bone mineral density and CAC.
Results
The control group demonstrated a significant increase in Agatston scores (187.79 ± 72.27) (
P
= 0.004). However, no significant change was noted in the denosumab group (
P
= 0.41). In the denosumab group, only the baseline serum alkaline phosphatase levels correlated negatively with changes in the CAC score (
P =
0.01); the baseline alkaline phosphatase levels were the deciding biomarkers for non-responsive CAC scores by Berry Criteria after denosumab treatment (
P
= 0.02). The denosumab group demonstrated significantly increased bone mineral density in the femoral neck and lumbar spine (
P
< 0.01).
Conclusion
The findings provide evidence that denosumab may suppress the progression of CAC and also regress osseous calcification in severe cases of high bone turnover.
Thermoelectrics have long been recognized as a potentially transformative energy conversion technology due to their ability to convert heat directly into electricity. Despite this potential, ...thermoelectric devices are not in common use because of their low efficiency, and today they are only used in niche markets where reliability and simplicity are more important than performance. However, the ability to create nanostructured thermoelectric materials has led to remarkable progress in enhancing thermoelectric properties, making it plausible that thermoelectrics could start being used in new settings in the near future. Of the various types of nanostructured materials, bulk nanostructured materials have shown the most promise for commercial use because, unlike many other nanostructured materials, they can be fabricated in large quantities and in a form that is compatible with existing thermoelectric device configurations. The first generation of these materials is currently being developed for commercialization, but creating the second generation will require a fundamental understanding of carrier transport in these complex materials which is presently lacking. In this review we introduce the principles and present status of bulk nanostructured materials, then describe some of the unanswered questions about carrier transport and how current research is addressing these questions. Finally, we discuss several research directions which could lead to the next generation of bulk nanostructured materials.
We present the first experimental evidence supported by simulations of kinetic effects launched in the interpenetration layer between the laser-driven hohlraum plasma bubbles and the corona plasma of ...the compressed pellet at the Shenguang-III prototype laser facility. Solid plastic capsules were coated with carbon-deuterium layers; as the implosion neutron yield is quenched, DD fusion yield from the corona plasma provides a direct measure of the kinetic effects inside the hohlraum. An anomalous large energy spread of the DD neutron signal (∼282 keV) and anomalous scaling of the neutron yield with the thickness of the carbon-deuterium layers cannot be explained by the hydrodynamic mechanisms. Instead, these results can be attributed to kinetic shocks that arise in the hohlraum-wall-ablator interpenetration region, which result in efficient acceleration of the deuterons (∼28.8 J, 0.45% of the total input laser energy). These studies provide novel insight into the interactions and dynamics of a vacuum hohlraum and near-vacuum hohlraum.
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