Parametric attosecond pulse amplification far from the ionization threshold from high order harmonic generation in He+^+

Parametric amplification of attosecond coherent pulses around 100 eV at the single-atom level is demonstrated for the first time by using the 3D time-dependent Schr{\"o}dinger equation in high-harmonic generation processes from excited states of He$^+$. We present the attosecond dynamics of the amplification process far from the ionization threshold and resolve the physics behind it. The amplification of a particular central photon energy requires the seed XUV pulses to be perfectly synchronized in time with the driving laser field for stimulated recombination to the He$^+$ ground state and is only produced in a few specific laser cycles in agreement with the experimental measurements. Our simulations show that the amplified photon energy region can be controlled by varying the peak intensity of the laser field. Our results pave the way to the realization of compact attosecond pulse intense XUV lasers with broad applications

All-solid-state VUV frequency comb at 160 nm using high-harmonic generation in nonlinear femtosecond enhancement cavity

© 2019 Optical Society of America. Users may use, reuse, and build upon the article, or use the article for text or data mining, so long as such uses are for non-commercial purposes and appropriate attribution is maintained. All other rights are reserved.We realized a solid-state-based vacuum ultraviolet frequency comb by harmonics generation in an external enhancement cavity. Optical conversions were so far reported by only using gaseous media. We present a theory that allows the most suited solid generation medium to be selected for specific target harmonics by adapting the material’s bandgap. We experimentally use a thin AlN film grown on a sapphire substrate to realize a compact frequency comb high-harmonic source in the Deep Ultraviolet (DUV)/Vacuum Ultraviolet/Deep Ultraviolet (VUV) spectral range. By extending our earlier VUV source [Opt. Express 26, 21900 (2018)] with the enhancement cavity, a sub-Watt level Ti:sapphire femtosecond frequency comb is enhanced to 24 W stored average power, its 3rd, 5th, and 7th harmonics are generated, and the targeted 5th harmonic’s power at 160 nm increased by two orders of magnitude. The emerging nonlinear effects in the solid medium, together with suitable intra-cavity dispersion management, support optimal enhancement and stable locking. To demonstrate the realized frequency comb’s spectroscopic ability, we report on the beat measurement between the 3rd harmonic beam and a 266 nm CW laser reaching about 1 MHz accuracy.Peer ReviewedPostprint (published version

Tumour necrosis factor-α and adenosine in endotoxin shockleading related cardiovascular symptoms

We have observed uncontrollable cardiogenic shock as a cardiovascular manifestation of systemic inflammatory response syndrome (SIRS) leading to death in a 62-year-old woman. The diagnosis of SIRS was based on the demonstration of endotoxinaemia, and highly elevated plasma levels of tumour necrosis factor (TNF)-α, and interleukin (IL)-10. We suggest that these cytokines may contribute to the terminal SIRS-related arrythmias, impaired myocardial contractility, as well as increased vascular permeability. In addition, the increased production of adenosine, a counter-regulatory mediator of inflammation, may also play a role in cardiodepression. We suggest a relationship between the action of TNF-α , IL-10 and adenosine in the pathogenesis of circulatory symptoms described above

Object-oriented Programming Laws for Annotated Java Programs

Object-oriented programming laws have been proposed in the context of languages that are not combined with a behavioral interface specification language (BISL). The strong dependence between source-code and interface specifications may cause a number of difficulties when transforming programs. In this paper we introduce a set of programming laws for object-oriented languages like Java combined with the Java Modeling Language (JML). The set of laws deals with object-oriented features taking into account their specifications. Some laws deal only with features of the specification language. These laws constitute a set of small transformations for the development of more elaborate ones like refactorings

Determining the 7Li(n,gamma) cross section via Coulomb dissociation of 8Li

The applicability of Coulomb dissociation reactions to determine the cross section for the inverse neutron capture reaction was explored using the reaction 8Li(gamma,n)7Li. A 69.5 MeV/nucleon 8Li beam was incident on a Pb target, and the outgoing neutron and 7Li nucleus were measured in coincidence. The deduced (n,gamma) excitation function is consistent with data for the direct capture reaction 7Li(n,gamma)8Li and with low-energy effective field theory calculations.Comment: Accepted for publication in Phys. Rev.

Amygdala subnuclei response and connectivity during emotional processing

The involvement of the human amygdala in emotion-related processing has been studied using functional magnetic resonance imaging (fMRI) for many years. However, despite the amygdala being comprised of several subnuclei, most studies investigated the role of the entire amygdala in processing of emotions. Here we combined a novel anatomical tracing protocol with event-related high-resolution fMRI acquisition to study the responsiveness of the amygdala subnuclei to negative emotional stimuli and to examine intra-amygdala functional connectivity. The greatest sensitivity to the negative emotional stimuli was observed in the centromedial amygdala, where the hemodynamic response amplitude elicited by the negative emotional stimuli was greater and peaked later than for neutral stimuli. Connectivity patterns converge with extant findings in animals, such that the centromedial amygdala was more connected with the nuclei of the basal amygdala than with the lateral amygdala. Current findings provide evidence of functional specialization within the human amygdala