Jožef Stefan Institute

About: Jožef Stefan Institute is a facility organization based out in Ljubljana, Slovenia. It is known for research contribution in the topics: Liquid crystal & Dielectric. The organization has 3828 authors who have published 12614 publications receiving 291025 citations.

Inhibitory effect of carnosic acid on HIV-1 protease in cell-free assays [corrected].

Abstract: In order to find new effective HIV protease inhibitors, two diterpenes (carnosic acid [1] and carnosol [5]) were isolated from rosemary (Rosmarinus officinalis L.), and rosmanol [2] and semisynthetic derivatives (7-O-methylrosmanol [3], 7-O-ethylrosmanol [4], and 11,12-O,O-dimethylcarnosol [6]) were prepared. The inhibitory activity of all six compounds against HIV-1 protease was tested. The carnosic acid [1] showed the strongest inhibitory effect (IC90 = 0.08 micrograms/ml). The same compound was also assayed against HIV-1 virus replication (IC90 = 0.32 micrograms/ml). The cytotoxic TC90 on H9 lymphocytes was 0.36 micrograms/ml, which is very close to the effective antiviral dose. Additionally, the tested compounds did not inhibit cellular aspartic proteases cathepsin D and pepsin at the concentration range up to 10 micrograms/ml [corrected].

Leptoquark mechanism of neutrino masses within the grand unification framework

Abstract: We demonstrate the viability of the one-loop neutrino mass mechanism within the framework of grand unification when the loop particles comprise scalar leptoquarks (LQs) and quarks of the matching electric charge. This mechanism can be implemented in both supersymmetric and non-supersymmetric models and requires the presence of at least one LQ pair. The appropriate pairs for the neutrino mass generation via the up-type and down-type quark loops are $$S_3$$ – $$R_2$$ and $$S_{1,\,3}$$ – $$\tilde{R}_2$$ , respectively. We consider two distinct regimes for the LQ masses in our analysis. The first regime calls for very heavy LQs in the loop. It can be naturally realized with the $$S_{1,\,3}$$ – $$\tilde{R}_2$$ scenarios when the LQ masses are roughly between $$10^{12}$$ and $$5 \times 10^{13}$$ GeV. These lower and upper bounds originate from experimental limits on partial proton decay lifetimes and perturbativity constraints, respectively. Second regime corresponds to the collider accessible LQs in the neutrino mass loop. That option is viable for the $$S_3$$ – $$\tilde{R}_2$$ scenario in the models of unification that we discuss. If one furthermore assumes the presence of the type II see-saw mechanism there is an additional contribution from the $$S_3$$ – $$R_2$$ scenario that needs to be taken into account beside the type II see-saw contribution itself. We provide a complete list of renormalizable operators that yield necessary mixing of all aforementioned LQ pairs using the language of SU(5). We furthermore discuss several possible embeddings of this mechanism in SU(5) and SO(10) gauge groups.

Keung-Senjanović process at the LHC: From lepton number violation to displaced vertices to invisible decays

Abstract: In the context of left-right symmetry, we revisit the Keung-Senjanovi\ifmmode \acute{c}\else \'{c}\fi{} production of right-handed ${W}_{R}$ bosons and heavy neutrinos $N$ at high energy colliders. We develop a multibinned sensitivity measure and use it to estimate the sensitivity for the entire range of $N$ masses, spanning the standard and merged prompt signals, displaced vertices and the invisible $N$ region. The estimated sensitivity of the LHC with 300/fb integrated luminosity ranges from 5 to beyond 7 TeV, while the future 33(100) TeV collider's reach with 3/ab extends to 12(26) TeV.