Tinnitus is a symptom frequently encountered by ear, nose, and throat practitioners. A causal treatment is rarely possible, and drug and nondrug treatment options are limited. One of the frequently prescribed treatments is Ginkgo biloba extract. Therefore, randomized, placebo-controlled clinical trials of Ginkgo biloba extract preparations were searched for and reviewed systematically. There is evidence of efficacy for the standardized extract, EGb 761® (Dr Willmar Schwabe GmbH & Co KG Pharmaceuticals, Karlsruhe, Germany), in the treatment of tinnitus from three trials in patients in whom tinnitus was the primary complaint. Supportive evidence comes from a further five trials in patients with age-associated cognitive impairment or dementia in whom tinnitus was present as a concomitant symptom. As yet, the efficacy of other ginkgo preparations has not been proven, which does not necessarily indicate ineffectiveness, but may be due to flawed clinical trials. In conclusion, EGb 761®, a standardized Ginkgo biloba extract, is an evidence-based treatment option in tinnitus.

We demonstrate optical guiding of high-intensity laser pulses in long, low density hydrodynamic optical-field-ionized (HOFI) plasma channels. An axicon lens is used to generate HOFI plasma channels with on-axis electron densities as low as ne(0) = 1.5 × 10 17 cm −3 and matched spot sizes in the range 20 µm WM 40 µm. Control of these channel parameters via adjustment of the initial cell pressure and the delay after the arrival of the channel-forming pulse is demonstrated. For laser pulses with a peak axial intensity of 4 × 10 17 W cm −2 , highly reproducible, high-quality guiding over more than 14 Rayleigh ranges is achieved at a pulse repetition rate of 5 Hz, limited by the available channel-forming laser and vacuum pumping system. Plasma channels of this type would seem to be well suited to multi-GeV laser wakefield accelerators operating in the quasi-linear regime.Many applications of high-intensity laser-plasma interactions require the propagation of high-intensity laser pulses through plasmas which are orders of magnitude longer than the Rayleigh range. One example of particular current interest is the laser wakefield accelerator (LWFA) [1], in which a laser pulse with an intensity of order 10 18 W cm −2 propagates though a plasma, driving a trailing density wave. The electric fields generated within this plasma wave are of the order of the wave-breaking field E 0 = m e ω p c/e, where ω p = (n e e 2 /m e ǫ 0 ) 1/2 and n e is the electron density [2,3]. For plasma densities in the range n e = 10 17 −10 18 cm −3 , E 0 ≈ 30 − 100 GV m −1 , which is several orders of magnitude higher than the fields generated in radio-frequency machines.Plasma accelerators can drive compact sources of femtosecond-duration [4-6] radiation via betatron emission [7,8], undulator radiation [9, 10], and Thomson scattering [11][12][13], with many potential applications in ultrafast science. In the longer term they could provide a building block for future high-energy particle colliders [14].For LWFAs operating in the quasilinear regime [2], the energy gain per stage varies as W ∝ E 0 L acc ∝ 1/n e , and the required length of the stage varies as L acc ∝ 1/n 3/2 e . Hence reaching higher energy gains requires the drive laser to propagate over longer lengths of lower density plasma.To date, the highest reported electron energy generated in a LWFA is 7.8 GeV, which was achieved by guiding intense laser pulses through a 200-mm-long plasma channel with an axial electron density of 2.7 × 10 17 cm 3 [15].Laser-plasma accelerators providing 10 GeV energy gain per stage will require laser guiding through 100s of millimetres of plasma of electron density n e ≈ 10 17 cm −3 [16,17]. Further, for many of the applications identified above it will be necessary to operate at pulse repetition rates, f rep , several orders of magnitude above the few hertz typical of today's GeV-scale LWFAs.To date, the workhorse waveguide for LWFAs has been the capillary discharge waveguide [18,19]. Capillary discharge waveguides have generated plasma channels up to 150...

Measurements of the physical properties of stars at the lower end of the main sequence are scarce. In this context we report masses, radii and surface gravities of ten very-low-mass stars in eclipsing binary systems, with orbital periods of the order of several days. The objects probe the stellar mass-radius relation in the fully convective regime, M 0.35 M , down to the hydrogen burning mass-limit, M HB ∼ 0.07 M . The stars were detected by the WASP survey for transiting extra-solar planets, as low-mass, eclipsing companions orbiting more massive, F-and G-type host stars. We use eclipse observations of the host stars, performed with the TRAPPIST, Leonhard Euler and SPECULOOS telescopes, and radial velocities of the host stars obtained with the CORALIE spectrograph, to determine the physical properties of the low-mass companions. Surface gravities of the low-mass companions are derived from the eclipse and orbital parameters of each system. Spectroscopic measurements of the host star effective temperature and metallicity are used to infer the host star mass and age from stellar evolution models for solar-type stars. Masses and radii of the low-mass companions are then derived from the eclipse and orbital parameters of the binary systems. The objects are compared to stellar evolution models for low-mass stars, to test for an effect of the stellar metallicity and orbital period on the radius of low-mass stars in close binary systems. Measurements are found to be in good agreement with stellar evolution models; a systematic inflation of the radius of low-mass stars with respect to model predictions is limited to 1.6 ± 1.2%, in the fully convective low-mass regime. The sample of ten objects indicates a scaling of the radius of low-mass stars with the host star metallicity. No correlation between stellar radii and the orbital periods of the binary systems is determined. A combined analysis with thirteen comparable objects from the literature is consistent with this result.Article published by EDP Sciences A150, page 1 of 18 A&A 625, A150 (2019)

We report the discovery of an eclipsing binary system with mass-ratio q ∼ 0.07. After identifying a periodic photometric signal received by WASP, we obtained CORALIE spectroscopic radial velocities and follow-up light curves with the Euler and TRAPPIST telescopes. From a joint fit of these data we determine that EBLM J0555-57 consists of a sun-like primary star that is eclipsed by a low-mass companion, on a weakly eccentric 7.8-day orbit. Using a mass estimate for the primary star derived from stellar models, we determine a companion mass of 85 ± 4 M Jup (0.081 M ) and a radius of 0.84 +0.14 −0.04 R Jup (0.084 R ) that is comparable to that of Saturn. EBLM J0555-57Ab has a surface gravity log g 2 = 5.50 +0.03 −0.13 and is one of the densest non-stellar-remnant objects currently known. These measurements are consistent with models of low-mass stars.Key words. binaries: eclipsing -binaries: spectroscopic -stars: low-mass -techniques: spectroscopic -techniques: photometricstars: individual: EBLM J0555-57AbEclipsing binary stars enable empirical measurements of the stellar mass-radius relation. The low-mass regime, down to the hydrogen-burning mass limit, is poorly constrained by measurements of mass and radius, but is of particular relevance to the study of exoplanets. Stars with masses below 0.25 M are the most common stellar objects (Kroupa 2001;Chabrier 2003;Henry et al. 2006) and prove to be excellent candidates for the detection of Earth-sized planets (Berta- Gillon et al. 2016Gillon et al. , 2017Luger et al. 2017) and their atmospheric characterization (de Wit et al. 2016). Determining the properties of exoplanets requires an accurate knowledge of their host star parameters, in particular the stellar mass. This motivates the study of low-mass eclipsing binaries (henceforth EBLMs; Triaud et al. 2013;Gómez Maqueo Chew et al. 2014), to empirically measure the mass-radius relation. In this context, we report our results on the eclipsing binary EBLM J0555-57. The system was detected by the Wide Angle Search for PlanetsThe photometry tables and radial velocities are only available at the CDS and on demand via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5)