Low frequency-to-intensity noise conversion in a pulsed laser cavity locking by exploiting carrier envelope offset

We report on the dependence of the frequency-to-intensity noise conversion in the locking of an ultrafast laser against a high-finesse optical enhancement resonator from the carrier envelope offset frequency. By a proper combination of the cavity finesse and laser carrier envelope offset frequency, it is possible to optimize the signal-to-noise ratio of the laser intensity trapped into the optical resonator. In this paper, we describe the effect of the laser-enhancement cavity coupling on the intracavity power relative noise, and we demonstrate both theoretically and experimentally its reduction

Formyl Peptide Receptor (FPR)1 Modulation by Resveratrol in an LPS-Induced Neuroinflammatory Animal Model

Among therapeutic approaches that have been investigated, targeting of receptors implicated in managing neuroinflammation has been described. One such family of receptors comprises the formyl peptide receptors (FPRs) whose ligands could play a role in host defense. The murine FPR gene family includes at least six members while in humans there are only three. The two most important members are the Fpr1 and Fpr2. Fpr1encodes murine FPR1, which is considered the murine orthologue of human FPR. Resveratrol, a non-flavonoid polyphenol rich in red wine and grapes, apart from its beneficial health effects and anti-inflammatory properties, has been reported to reduce neuroinflammation in different neurodegenerative disease models. Resveratrol anti-inflammatory responses involve the activation of the protein deacetylase sirtuin 1 (SIRT1) gene. In this work we have investigated in an LPS-based murine model of neuroinflammation the role of FPR1, examining not only if this receptor undergoes a reduction of its expression during neuroinflammation, but also whether treatment with resveratrol was able to modulate its expression leading to an amelioration of neuroinflammatory picture in a murine model of neuroinflammation. Results of this work showed that FPR1 together with SIRT1 resulted upregulated by resveratrol treatment and that this increase is associated with an amelioration of the neuroinflammatory picture, as demonstrated by the induction of IL-10 and IL1-RA expression and the downregulation of proinflammatory mediators, such as TNF-α and IL-1β. The expression and the modulation of FPR1 by resveratrol may be evaluated in order to propose a novel anti-inflammatory and pro-resolving therapeutic approach for the reduction of the detrimental effects associated with neuro-inflammation based neurodegenerative diseases and also as a promising strategy to promote human health by a diet rich in antioxidative bioactive compounds

A new method for spatial mode shifting of stabilized optical cavities for the generation of dual-color X-rays

We propose an innovative method to shift the transversal position of the focal point of an optical cavity keeping it actively frequency stabilized. Our cavity is a 4 mirrors bow-tie cavity and the spatial shift of the resonant mode is obtained by properly rotating the two curved mirrors by piezo actuators. This method allows us to move the transversal position of the cavity focal point of 135 µm in a time of 50 ms, keeping the resonance condition of the cavity by means of the Pound–Drever–Hall technique. We propose to use this technique for the generation of 2-color X-rays via Inverse Compton Scattering (ICS). This technique exploits the large average power stored in the high finesse cavity by shifting the laser beam with respect to the electron beam trajectory, hence controlling the spatial superposition of the electron and photon beams in the interaction region. Arranging two cavities assembled one on top of the other, with different collision angle with the electron beam, allows the generation of X-ray bursts of different energies just by swiftly moving the two cavities, switching the two focal points onto the electron beam trajectory, thus activating in sequence two different ICS spectral lines

Alexithymia, Metacognition, and Theory of Mind in Children and Preadolescents With Migraine Without Aura (MWoA): A Case-Control Study

Background: Some studies have demonstrated the high impact of headache and migraine in several areas of children and adolescents’ life. In recent years, there has been an increase in scientific interest in the relationship between migraine and emotional regulation, investigating the possible consequences of emotional dysregulation on physical and mental health. While some studies have been carried out on the relationship between alexithymia and headache or migraine (especially in adults), no data exist on relationship between Theory of Mind (TOM), metacognition, and alexithymia in children and adolescents with migraine. Methods: Children with diagnosis of migraine without aura (MWoA) (36 males and 34 females) were compared to a healthy control group (31 males and 39 females). The age range was from 8 to 13 years in both groups. All children completed the Alexithymia Questionnaire for Children (AQC) for the assessment of alexithymia levels and the Domain of Social Perception included in the NEPSY-II to evaluate levels of TOM. Metacognitive development was evaluated with Io e La Mia Mente for children aged between 8 and 10 years and with Metacognitions Questionnaire for Children (MCQ-C) for children from 11 to 13. Results: There were no differences between children with MWoA and the control group in metacognitive abilities; only in the subscale “Negative Meta Worrying” of MCQ-C girls scored higher than boys, regardless of the group they were part of. Also, in the NEPSY-II subscale there were no statistically significant differences between the two groups. Children with MWoA scored higher in the AQC subscales “Difficulty Identifying Feelings” and “Difficulty Describing Feelings” than controls. Moreover, children between 8 and 10 years statistically differed from older children in “Difficulty Identifying Feelings” and in Total Score. Conclusion: Our data suggest that children with MWoA have no metacognitive and TOM problems compared to a healthy group. The experimental group showed higher traits of alexithymia, confirming what suggested by other studies in the literature. Future research will have to focus on migraine with aura and tension-type headache to evaluate any differences with children with MWoA

Mesoscopic organization of cobalt thin films on clean and oxygen-saturated Fe(001) surfaces

The different morphologies of Co films grown on either the clean Fe(001) surface and the oxygen-saturated Fe(001)-p(1 71)O substrate are investigated by means of scanning tunneling microscopy, Auger electron spectroscopy, and density functional theory. The considered Co coverage range extends beyond the thickness at which layer-by-layer growth is destabilized by plastic deformations induced by the relaxation of the strain accumulated in the film. Our findings indicate that the oxygen overlayer of the Fe(001)-p(1 71)O surface floats on top of the growing Co film and strongly influences both the Co nucleation process and the film structural evolution. The layer-dependent islands nucleation of Co films grown on clean Fe(001) substrates, recently associated with a thickness-dependent adatom mobility [A. Picone et al., Phys. Rev. Lett. 113, 046102 (2014)], is found to be suppressed by the oxygen overlayer. The latter also significantly delays the layer-by-layer instability with respect to the oxygen-free growth. Furthermore, the body-centered-tetragonal/hexagonal-close-packed transition is not observed in the case of Co/Fe(001)-p(1 71)O sample, replaced by the development of highly ordered surface undulations. These form a mesoscopic square pattern with the sides aligned to the Fe\u27e8110\u27e9 directions, while the surface atomic structure retains the square p(1 71) symmetry in registry with the substrate. Such undulations are likely generated by a highly ordered array of interfacial misfit dislocations running along the Fe\u27e8110\u27e9 directions

BriXs ultra high fluxinverse compton source based on modified push-pull energy recovery linacs

We present a conceptual design for a compact X-ray Source BriXS (Bright and compact X-ray Source). BriXS, the first stage of the Marix project, is an Inverse Compton Source (ICS) of X-ray based on superconducting cavities technology for the electron beam with energy recirculation and on a laser system in Fabry-Pérot cavity at a repetition rate of 100 MHz, producing 20–180 keV monochromatic X-Rays devoted mainly to medical applications. An energy recovery scheme based on a modified folded push-pull CW-SC twin Energy Recovery Linac (ERL) ensemble allows us to sustain an MW-class beam power with almost one hundred kW active power dissipation/consumption

Intercalation from the Depths: Growth of a Metastable Chromium Carbide between Epitaxial Graphene and Ni(111) by Carbon Segregation from the Bulk

The intercalation of atoms or small molecules underneath graphene epitaxially grown on single metal surfaces is a widely exploited method for modifying the interaction between the carbon monolayer and the substrate. Despite it would be highly desirable to expand the class of the intercalants by including also metal compounds such as oxides, nitrides, or carbides, their use as decoupling layers is a much more challenging task. Here, we demonstrate that it is possible to intercalate an ultrathin layer of Cr-carbide at the graphene/Ni(111) interface by using the carbon dissolved in the bulk of the substrate as a reservoir. Auger electron spectroscopy reveals that Cr deposition on the graphene/Ni(111) interface triggers C segregation from the Ni bulk, while the graphene layer floats on top of the growing film. Scanning tunneling microscopy shows the presence of a periodic superstructure on the surface, due to a coincidence lattice at the graphene/carbide boundary or alternatively to a dislocation network developing at the carbide/Ni(111) interface. Scanning tunneling spectra normalized to the total conductance indicate that the density of states around the Fermi level depends linearly on the energy, suggesting that the graphene layer is electronically decoupled from the Cr-carbide film