We report on the successful ‘‘soft landing’’ of size selected silver dimers and trimers in solid krypton matrices. Silver cluster cations, produced by sputtering, were mass selected in a quadrupole mass filter and then codeposited with krypton on a cooled sapphire or CaF2 window in the presence of low energy electrons. Neutralized cluster samples were interrogated in situ by excitation and fluorescence spectroscopy. Deposition of slow (≤20 eV) silver dimer cations gave rise to strong excitation bands (centered at λ=275 and 390 nm) from Ag2 plus the characteristic triplet signal of the atom. The spectra imply that fewer than 25% of the dimers were fragmented during the neutralization and deposition steps. In similar experiments with Ag3 we were able to assign trimer absorption bands at 331, 364, 402, 421, 458, and 514 nm and identify characteristic emission features at 381, 560, and 626 nm.

The velocity map of the above-threshold ionization electron spectrum at long laser wavelength exhibits a characteristic structure normal to the laser polarization, which has the appearance of a trident or a three-pronged fork. The forklike structure vanishes for few-cycle laser pulses. It is explained in terms of the classical-electrontrajectories model of strong-field ionization augmented so as to allow for rescattering. The analysis reveals its relation to the so-called low-energy structure, which was recently observed for very small transverse momenta. An atom exposed to an intense laser field provides one of the simplest physical realizations of a nonlinearly driven system. It has revealed various phenomena that have generated subfields of their own, such as the generation of high harmonics of the incident laser field, which in turn has brought us attosecond pulses [1]. In contrast to high-order harmonic generation, ionization of atoms can be investigated as a pure single-atom event; macroscopic effects have no significance. Especially, above-threshold ionization (ATI) has caught the interest of experimentalists and theorists alike, ever since its first observation 35 years ago [2,3]. ATI is characterized by the fact that the atom absorbs more photons than are necessary for ionization.In view of the simplicity of the system in question-in principle, as simple as hydrogen [4]-it is remarkable that novel features of ATI have continued to emerge. Recent examples include frustrated tunneling ionization (FTI) [5] and a carpetlike pattern in the ionization velocity map at about right angle to the laser polarization [6] and, for comparatively long laser wavelengths, the so-called low-energy structure (LES) [7] and spiderlike interference structures (SPIDER) that were interpreted as holograms [9][10][11]. The most recent such examples include a structure with an energy below the LES, the very-low-energy structure [12] and a strong enhancement at practically zero energy [13]. The latter two are assumed to be Coulomb-related effects, but there is no consensus as to their detailed origin. ATI is also the basis of various applications: For example, analysis of the velocity map at high energy allows one to extract the electron-ion scattering potential [14] while the details of the spider structure are sensitive to the atomic potential [11]. It also has been used to measure the carrier-envelope phase of few-cycle pulses [15,16].In this letter, strong-field ionization into states with low electron energy by a long-wavelength laser field is investigated experimentally and modeled theoretically. We compare the velocity map of the electron spectrum which is generated by a * max.moeller@uni-jena.de long laser pulse with the one generated by a few-cycle pulse. Besides retrieving the LES and the SPIDER, we observe a third-so far unadressed-fork-like structure which has a shape reminiscent of a trident or three-pronged fork (from here on, we will refer to it by the fork). The fork appears at close to right angle to the laser polar...

Purpose: To evaluate the efficacy and safety of intravitreal implant of dexamethasone (Ozurdex®) in diabetic macular edema (DME). Methods: This was a retrospective multicenter noncomparative study. Seventy-eight patients with DME followed for at least 6 months were included (P1.5 Network). Best-corrected visual acuity (BCVA), central retinal thickness (CRT), intraocular pressure (IOP) and cataract progression were studied at baseline and then at 1, 2, 4 and 6 months. Results: The mean CRT decrease from baseline was 145.2 µm at 6 months. The mean BCVA improvement from baseline was 6.7 at 6 months. An increase in IOP was observed for 11.7% of patients, and all patients were managed by topical treatment. No glaucoma or cataract surgery was necessary, and no endophthalmitis was reported. Conclusions: One injection of Ozurdex has an anatomical and functional effectiveness for the treatment of DME. Side effects were rare and manageable in our practice.

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Absolute cross sections have been measured for electron-impact ionization of Fe ions of initial charges 5+, 6+, and 9+ from below' threshold to 1500-eV collision energies. Distorted-eave calculations including only direct ionization from ground-state ions underestimate the measured peak cross sections by 60 -70% due to the effects of metastable states and contributions of excitation autoionization to the total cross sections. Ionization rate coefficients and fitting parameters are presented for this data and for Fe+ and Fe~+.

Multiple gunshot suicide can be a controversial subject mainly because of wrong opinions concerning immediate incapacitation or alleged backwards hurling. For the last 20 years, experts in medicine and physics have tried to demonstrate what really happens during a gunshot wound. Different methods have been used to achieve this aim such as basic physics or the use of empirical evidence. In this paper, using a finite element model of the human head, we demonstrate that no incapacitation or backwards hurling can occur from a gunshot fired between the eyes which did not enter the cerebrum.

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