Portable fiber-optic laser-induced breakdown spectroscopy system for the quantitative analysis of minor elements in steel

In this paper, we developed a portable laser-induced breakdown spectroscopy(LIBS) using an optical fiber to deliver laser energy and used it to quantitatively analyze minor elements in steel.The R^2 factors of calibration curves of elements Mn, Ti, V, and Cr in pig iron were 0.9965,0.9983, 0.9963, and 0.991, respectively, and their root mean square errors of cross-validation were 0.0501, 0.0054, 0.0205, and 0.0245 wt%, respectively. Six test samples were used for the validation of the performance of the calibration curves established by the portable LIBS. The average relative errors of elements Mn, Ti, V, and Cr were 2.5%, 11.7%, 13.0%, and 5.6%,respectively. These results were comparable with most results reported in traditional LIBS in steel or other matrices. However, the portable LIBS is flexible, compact, and robust, providing a promising prospect in industrial application.

Noninvasive in vivo study of NADH fluorescence and its real-time intrinsic dynamical changes: Experiments and seven-layered skin model Monte Carlo simulations

Reduced nicotinamide adenine dinucleotide(NADH)plays a crucial role in many biochemical reactions in human metabolism.In this work,a flow-mediated skin fluorescence(FMSF)-postocclusion reactive hyperaemia(PORH)system was developed for noninvasive and in vivo measurement of NADH fluorescence and its real-time dynamical changes in human skin tissue.The real-time dynamical changes of NADH fluorescence were analyzed with the changes of skin blood flow measured by laser speckle contrast imaging(LSCI)experiments simultaneously with FMSFPORH measurements,which suggests that the dynamical changes of NADH fluorescence would be mainly correlated with the intrinsic changes of NADH level in the skin tissue.In addition,Monte Carlo simulations were applied to understand the impact of optical property changes on the dynamical changes of NADH fluorescence during the PORH process,which further supports that the dynamical changes of NADH fluorescence measured in our system would be intrinsic changes of NADH level in the skin tissue.

Editorial:Introduction to the special issue on bio-photonics in neuroscience and brain diseases

Photons with a great many tumable physical properties have been profoundly engaged in research of brain science in all aspects for more than a hundred years.Taking advantage of highly developed incoherent light sources,coherent lasers and short-pulse lasers,innovative optical tools including both instrument ations andstrategies have significantly boosted comprehensive research on neural science within a very short period.

Editorial-Introduction to the special issue on super-resolution optical microscopy

Super-resolution optical microscopy,sometimes called optical nanoscopy,refers to a new kind of far-¯eld optical microscopy which allows optical imaging with a resolution higher than the well-known resolution limit(or the Abbe di®raction limit)which stood for more than a century.The reported approaches that break the resolution limit involve either e®ectively reducing the focus region of the excitation light or stochastic separation and precise localization of single°uorophores.Super-resolution optical microscopy provides unprecedented opportunities for tackling outstanding fundamental questions in life science,medicine,materials,and many others that require non-invasive imaging with molecular level spatial resolution.