Implementation and application of FRET-FLIM technology

With the development of the new detection methods and the function of fluorescent molecule,researchers hope to further explore the internal mechanisms of organisms,monitor changes in the intracellular microenvironment,and dynamic processes of molecular interactions in cells.Fluo-rescence resonance energy transfer(FRET)describes the energy transfer process between donor fluorescent molecules and acceptor fluorescent molecules.It is an important means to detect protein-protein interactions and protein conformation changes in cells.Fluorescence lifetime imaging microscopy(FLIM)enables noninvasive measurement of the fAuorescence lifetime of fluorescent particles in vivo.The FRET-FLIM technology,which is use FLIM to quantify and analyze FRET,enables real-time monitoring of dynamic changes of proteins in biological cells and analysis of protein interaction mechanisms.The distance between donor and acceptor and their respective fAuorescent lifetime,which are of great importance for studying the mechanism of intracellular activity can be obtained by data analysis and algorithm ftting.

Deep learning autofluorescence-harmonic microscopy

Laser scanning microscopy has inherent tradeoffs between imaging speed,field of view(FOV),and spatial resolution due to the limitations of sophisticated mechanical and optical setups,and deep learning networks have emerged to overcome these limitations without changing the system.Here,we demonstrate deep learning autofluorescence-harmonic microscopy(DLAM)based on self-alignment attention-guided residual-in-residual dense generative adversarial networks to close the gap between speed,FOV;and quality.Using the framework,we demonstrate label-free large-field multimodal imaging of clinicopathological tissues with enhanced spatial resolution and running time advantages.Statistical quality assessments show that the attention-guided residual dense conneaions minimize the persistent noise,distortions,and scanning fringes that degrade the autofluorescence-harmonic images and avoid reconstruction artifaas in the output images.With the advantages of high contrast,high fidelity,and high speed in image reconstruction,DLAM can act as a powerful tool for the noninvasive evaluation of diseases,neural activity,and embryogenesis.

Simulation and analysis of the time evolution of laser power and temperature in static pulsed XPALs

A theoretical model is established to describe the thermal dynamics and laser kinetics in a static pulsed exciplex pumped Cs–Ar laser(XPAL).The temporal behaviors of both the laser output power and temperature rise in XPALs with a longtime pulse and multi-pulse operation modes are calculated and analyzed.In the case of long-time pulse pumping,the results show that the initial laser power increases with a rise in the initial operating temperature,but the laser power decreases quickly due to heat accumulation.In the case of multi-pulse operation,simulation results show that the optimal laser output power can be obtained by appropriately increasing the initial temperature and reducing the thermal relaxation time.