Barrier Paradox in the Klein Zone

We study the solutions for a one-dimensional electrostatic potential in the Dirac equation when the incoming wave packet exhibits the Klein paradox (pair production). With a barrier potential we demonstrate the existence of multiple reflections (and transmissions). The antiparticle solutions which are necessarily localized within the barrier region create new pairs with each reflection at the potential walls. Consequently we encounter a new paradox for the barrier because successive outgoing wave amplitudes grow geometrically.Comment: 10 page

Timelapse

We discuss the existence in an arbitrary frame of a finite time for the transformation of an initial quantum state into another e.g. in a decay. This leads to the introduction of a timelapse $\tilde{\tau}$ in analogy with the lifetime of a particle. An argument based upon the Heisenberg uncertainty principle suggests the value of $\tilde{\tau}=1 / M_0$. Consequences for the exponential decay formula and the modifications that $\tilde{\tau}$ introduces into the Breit-Wigner mass formula are described.Comment: 5 pages [2 figs], ReV-Te

The role of miRNA-133b and its target gene SIRT1 in FAP-derived desmoid tumor.

Signaling pathways have a key role in driving the uncontrolled development of familial adenomatous polyposis (FAP)- associated and sporadic desmoid tumors (DTs). The relationship between the Wnt/b-catenin signaling pathway and DTs has been extensively studied, but no reliable biomarkers able to detect their histological subtype have been identified for the accurate diagnosis. In this study we studied the differences in miRNA expression between sporadic (20 patients) and FAP-associated DTs (7 patients) using microarray confirmed by quantitative PCR (qPCR). The analysis showed 19 dysregulated miRNAs. Among them miR-133b levels were significantly lower in FAP-associated DT than in sporadic DT. Therefore, two mRNAs, associated to miR-133b and β-catenin expression, the SIRT1 and ELAVL1were analyzed. The qPCR analysis showed that SIRT1 mRNA levels were significantly up-regulated in FAP-associated DT than in sporadic DT, whereas no differences in ELAVL1 expression was observed between these two DT types. In addition, a negative correlation was observed between miR-133b and SIRT1 in FAP-associated DTs, but not in sporadic DTs. The miR-133b-SIRT1-β-catenin axis may represent a novel mechanism underlying progression of FAP-associated D

Remarks upon the mass oscillation formulas

The standard formula for mass oscillations is often based upon the approximation $t \approx L$ and the hypotheses that neutrinos have been produced with a definite momentum $p$ or, alternatively, with definite energy $E$. This represents an inconsistent scenario and gives an unjustified reduction by a factor of two in the mass oscillation formulas. Such an ambiguity has been a matter of speculations and mistakes in discussing flavour oscillations. We present a series of results and show how the problem of the factor two in the oscillation length is not a consequence of gedanken experiments, i.e. oscillations in time. The common velocity scenario yields the maximum simplicity.Comment: 9 pages, AMS-Te

Fermion-Fermion Bound State Condition for Scalar Exchanges

The condition for the existence of a bound state between two fermions exchanging massive scalars is derived. For low scalar mass, we reproduce the scalar field model result. The high scalar mass result exhibits a somewhat different inequality condition

Experimental Study of the Effects of Three Types of Meat on Endothelial Function in a Group of Healthy Volunteers

Background: There is a relationship between atherosclerotic risk factors and increased vascular production of reactive oxygen species (ROS). Oxidized LDL and ROS may directly cause endothelial dysfunction by reducing endothelial nitric oxide (NO) bioavailability. The semi-essential amino acid L-arginine is the only substrate for NO synthesis in vascular endothelial cells. Therefore, this amino acid improves endothelial function and plays a role in the prevention and/or treatment of multiple cardiovascular diseases: atherosclerosis, hypertension, diabetes and so on. To determine the effects of three different protein matrices (250 g Fillet of Beef, FB; Chicken Raised on the Ground, CRG; Free-Range Chicken, FRC) with a known content of arginine on the cardiovascular workload, vascular compliance and urinary excretion of some parameters of endothelial function as TGF–Beta, NO (nitrate e nitrite) in a group of healthy volunteers. Materials and methods: We enrolled 10 men to study the behavior of Systolic, Diastolic, Mean, and Pulse Blood Pressure, of Vascular Resistances, of Macro and Micro Vascular Elasticity, of urinary excretion of TGF-β and Nitric Oxide as ratio of creatinine before and after two hours of each meal. The cardiovascular parameters are determined by HDI/Pulse Wave CR 2000 (Hypertension Diagnostic Inc, Eagan, MN); TGF-β is analysed by Elisa method (R&D Systems) and NO by colorimetric method (Cayman). Results and Conclusion: The protein meal packed with CRG causes a significant decrease in diastolic blood pressure mean pressure and vascular resistance in urinary excretion of TGF. FB resulted in a significant decrease in vascular resistance and urinary excretion of NO, while significantly increasing the Pulse Pressure, heart rate and urinary excretion of TGF-β. FRC resulted in a significant reduction of macrovascular elasticity; increase the urinary excretion of TGF and Pulse Pressure. We can conclude that CRG meat looks better both in terms of metabolic and cardiovascular load especially at endothelial level

Dirac Equation Studies in the Tunnelling Energy Zone

We investigate the tunnelling zone V0 < E < V0+m for a one-dimensional potential within the Dirac equation. We find the appearance of superluminal transit times akin to the Hartman effect.Comment: 12 pages, 4 figure

Potential Scattering in Dirac Field Theory

We develop the potential scattering of a spinor within the context of perturbation field theory. As an application, we reproduce, up to second order in the potential, the diffusion results for a potential barrier of quantum mechanics. An immediate consequence is a simple generalization to arbitrary potential forms, a feature not possible in quantum mechanics.Comment: 7 page