The Airy fibre: an optical fibre that guides light diffracted by a circular aperture

We have designed and made an optical fibre that guides an approximate Airy pattern as one of its guided modes. The fibre's attenuation was 11.0 dB/km at 1550 nm wavelength, the match between the fibre's mode and the ideal infinite Airy pattern was 93.7%, and the far field resembled a top-hat beam. The guidance mechanism has strong similarities to photonic bandgap guidance.Comment: 11 page

The Photonic Lantern

Photonic lanterns are made by adiabatically merging several single-mode cores into one multimode core. They provide low-loss interfaces between single-mode and multimode systems where the precise optical mapping between cores and individual modes is unimportant.Comment: 45 pages; article unchanged, accepted for publication in Advances in Optics and Photonic

Characterizing the variation of propagation constants in multicore fibre

We demonstrate a numerical technique that can evaluate the core-to-core variations in propagation constant in multicore fibre. Using a Markov Chain Monte Carlo process, we replicate the interference patterns of light that has coupled between the cores during propagation. We describe the algorithm and verify its operation by successfully reconstructing target propagation constants in a fictional fibre. Then we carry out a reconstruction of the propagation constants in a real fibre containing 37 single-mode cores. We find that the range of fractional propagation constant variation across the cores is approximately $\pm2 \times 10^{-5}$.Comment: 17 pages; preprint format; 5 figures. Submitted to Optics Expres

Historical Review and Update of Surgical Treatment for Corneal Endothelial Diseases

The cornea remains in a state of deturgescence, maintained by endothelial cell Na+/K+ ATPase and by tight junctions between endothelial cells that limit entrance of fluid into the stroma. Fuchs' endothelial corneal dystrophy (FECD) was initially described by Fuchs in 1910 as a combination of epithelial and stromal edema in older patients. It manifests as bilateral, albeit asymmetric, central corneal guttae, corneal edema, and reduced vision. When edema is severe, the corneal epithelium can detach from its basement membrane, creating painful bullae on the anterior surface of the cornea. The course of this dystrophy can be further accelerated after intraocular surgery, specifically cataract extraction. Pseudophakic bullous keratopathy (PBK) is endothelial cell loss caused by surgery in the anterior chamber. If the corneal endothelium is damaged during surgery, the same spectrum of symptoms as found in FECD can develop. In the nineteenth century, penetrating keratoplasty was the only surgical procedure available for isolated endothelial disease. In the 1960s, Dr. José Barraquer described a method of endothelial keratoplasty using an anterior approach via laser-assisted in situ keratomileusis (LASIK) flap. In 1999, Melles and colleague described their technique of posterior lamellar keratoplasty. Later, Melles et al. started to change host dissection using simple "descemetorhexis" in a procedure known as Descemet's stripping endothelial keratoplasty. Following the widespread adoption of Descemet's stripping automated endothelial keratoplasty, the Melles group revisited selective Descemet's membrane transplantation and reported the results of a new procedure, Descemet's membrane endothelial keratoplasty (DMEK). Recently, some eye banks have experimented with the preparation of DMEK/Descemet's membrane automated endothelial keratoplasty donor tissue that may help the surgeon avoid the risk of tissue loss during the stromal separation step. Recently, the authors described a new bimanual technique for insertion and positioning of endothelium-Descemet membrane grafts in DMEK

Quality assessment of pharmaceutical care to patients with headaches using the simulated patient method: drug recommendations and pharmaceutical counseling

Relevance. Headaches are one of the most important health problems both in Russia and around the world, as well as one of the most common reasons for self-treatment in a pharmacy due to the availability of over-the-counter drugs. Pharmaceutical workers play an important role in the control of self-medication, and the rationality of drug recommendations determines the quality of pharmaceutical care.Aim. To assess the rationality of drug recommendations for a patient with a headache and pharmaceutical drug counseling using the simulated patient method.Materials and methods. Trained simulated patients (women aged 20, 40 and 58 years) visited a total of 101 pharmacies. The dialogue was recorded on a voice recorder, all the features of the interaction were additionally recorded aſter the visit. Special forms were filled out based on the information received. The data was processed using Microsoſt Excel 2010 and STATISTIKA 10.0.Results. There was a high frequency of spontaneous recommendations without preliminary questions (66.3%), recommendations (14.9%) and dispensing of prescription drugs (5.0%), frequent recommendations of combined drugs (91.0%). Trade name Pentalgin (46.5%) and trade name Nurofen (42.6%), INN Ibuprofen (47.5%) were the most recommended. Combination analgesics were purchased in most of the visits (72.0%), information on the duration of use of the drug and the need to visit a doctor was never provided.Conclusion. Pharmacists' recommendations are in most cases irrational, focused on the drug as a product and sometimes unsafe, and counseling is practically non-existent. Improving the quality of pharmaceutical care at this stage should include the development of standards for drug recommendations and adequate counseling