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Using an all-fiber mode selective coupler (MSC) at the visible band, here we experimentally demonstrate a generating and wavelength multiplexing scheme for the cylindrical vector (CV) and vortex beams (VBs). The proposed MSCs act as efficient mode converters to produce spectrally insensitive high-order modes (HOMs) at the wavelength ranging from 450 to 980 nm, which have broad operation bandwidth (more than 7 nm), high mode conversion efficiency (94%), and purity (98%), and low insert loss (below 0.5 dB). By adjusting the polarization state and the phase shift of linear polarization (LP)11 mode respectively, the donut-shaped CVs and circular-polarization VBs are achieved. The focused intensity distribution of the donut beam on the cross- and axial-sections is monitored by using a confocal system. The all-fiber solution of producing and multiplexing HOMs opens a new route for stimulated emission depletion microscopy applications.

STimulated Emission Depletion (STED) microscopy attains super‐resolution in biological imaging beyond the diffraction limit. Here, we give a concise protocol to construct a dual‐pulse STED setup with one super‐continuum laser. Moreover, a flexible and dismountable Bessel modulation module is introduced for potential 2D‐stack STED imaging. Experiments and notices are introduced in detail, with discussion on some important check‐points for STED, such as detector saturation. Finally, the results validate the system working. [ABSTRACT FROM AUTHOR]

Objective To investigate changes in mitophagy and Amp-activated protein kinase (AMPK)/ UNC-51-like kinase 1 (ULK1) pathways in quadriceps femoris in rats with spleen qi deficiency and to explore the pathogenesis of "disuse of the four limbs due to spleen qi deficiency" from the perspective of mitochondria. Methods Rats were randomly divided into the control group and spleen qi deficiency group (model group). The models were established by irregular diet and exertion and then quadriceps femoris were taken out. Adenosine triphosphate ( ATP) content was detected by colorimetry and mitochondrial membrane potential (MMP) by JC-1. The expressions of light chain 3-B(LC3 B), selective autophagy adaptor protein (p62) and their co-localization with mitochondria were detected by Western blot and immunofluorescence. Finally, the expressions of AMPKα/ULK1 pathway proteins were detected by Western blot. Results Compared with the control group, ATP and MMP levels of quadriceps femoris were decreased in the model group (P < 0.05, P < 0.01). LC3B-II protein expression and its co-localization with mitochondria were increased (all P < 0.01) but p62 and its co-localization with mitochondria were decreased (all P < 0.01). Both p-AMPKα/AMPKα and p-ULK1/ULK1 ratios were increased (all P < 0.01). Conclusion "Limb disuse due to spleen qi deficiency" might be related to the insufficient increase in mitochondrial autophagy induced by the activation of AMPK/ULK1 pathway. [ABSTRACT FROM AUTHOR]