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Purpose. To evaluate early effects of hydroxychloroquine (HCQ) on the retina using adaptive optics (AO). Methods. This was a prospective observational single-center study of 29 eyes of 29 patients who had been treated with HCQ for the first time and followed with AO for a minimum of two years. Cone counting was performed in 4 quadrants, nasal, temporal, superior, and inferior, at 0.75 mm from the foveal center. The changes of cone density on AO, visual acuity, and foveal thickness within two years of use were analyzed. The changes of mean cone density of patients whose cumulative dose was over 200 g in 2 years were also assessed. We evaluated the correlation between cone density and cumulative dose of HCQ. Results. There was no significant decrease in cone density in the first 2 years of HCQ use. VA and foveal thickness did not show obvious change, either. Among 9 patients whose cumulative dose was over 200 g in 2 years, the mean cone density showed no significant change at 6, 12, 18, and 24 months compared with baseline (P = 0.381 , P = 0.380 , P = 0.281 , and P = 0.534 , respectively). There was no correlation between cone density and cumulative dose of HCQ at two years (Spearman's correlation coefficient, r = −0.0553, P = 0.780 ; n = 29). Conclusion. AO showed no change in cone density in the first two years of HCQ use. [ABSTRACT FROM AUTHOR]

A novel method to fabricate undulator magnets of a‐few‐millimetre‐period length is being explored. Plate‐type magnets, 100 mm‐long with 4 mm‐period length, have been successfully fabricated. They produce an undulator field of approximately 3 kG at a gap of 1.6 mm. Prototype undulators based on this technology have been constructed. Field measurements and characterization show that the quality of the undulator field of these plate magnets is sufficient for an undulator light source, and the calculated spectrum shows that the fundamental radiation emitted from this field is quite satisfactory. Test experiments for light generation using a real electron beam have been carried out at a test accelerator at the Research Center for Electron Photon Science (ELPH), Tohoku University, Japan, which is able to realize optics conditions to accept a very short gap of ∼1.6 mm. First observation and characterization of blue light was successfully accomplished. [ABSTRACT FROM AUTHOR]

Carbon contamination of optics is a serious issue in all soft X-ray beamlines because it decreases the quality of experimental data, such as near-edge X-ray absorption fine structure, resonant photoemission and resonant soft X-ray emission spectra in the carbon K-edge region. Here an in situ method involving the use of oxygen activated by zeroth-order synchrotron radiation was used to clean the optics in a vacuum ultraviolet and soft X-ray undulator beamline, BL-13A at the Photon Factory in Tsukuba, Japan. The carbon contamination of the optics was removed by exposing them to oxygen at a pressure of 10−1-10−4 Pa for 17-20 h and simultaneously irradiating them with zeroth-order synchrotron radiation. After the cleaning, the decrease in the photon intensity in the carbon K-edge region reduced to 2-5%. The base pressure of the beamline recovered to 10−7-10−8 Pa in one day without baking. The beamline can be used without additional commissioning. [ABSTRACT FROM AUTHOR]

We present the results of a joint project to identify the origin of a discrepancy between the value of the Si lattice-parameter obtained by the Istituto Nazionale di Ricerca Metrologica and that obtained by the National Metrology Institute of Japan. The re-evaluation of diffraction in the laser interferometry indicates that misalignment of the interfering beams could account for the observed difference. [ABSTRACT FROM AUTHOR]