Fluorescence polarization microscopy (FPM) aims to detect the dipole orientation of fluorophores and to resolve structural information for labeled organelles via wide-field or confocal microscopy. Conventional FPM often suffers from the presence of a large number of molecules within the diffraction-limited volume, with averaged fluorescence polarization collected from a group of dipoles with different orientations. Here, we apply sparse deconvolution and least-squares estimation to fluorescence polarization modulation data and demonstrate a super-resolution dipole orientation mapping (SDOM) method that resolves the effective dipole orientation from a much smaller number of fluorescent molecules within a sub-diffraction focal area. We further apply this method to resolve structural details in both fixed and live cells. For the first time, we show that different borders of a dendritic spine neck exhibit a heterogeneous distribution of dipole orientation. Furthermore, we illustrate that the dipole is always perpendicular to the direction of actin filaments in mammalian kidney cells and radially distributed in the hourglass structure of the septin protein under specific labelling. The accuracy of the dipole orientation can be further mapped using the orientation uniform factor, which shows the superiority of SDOM compared with its wide-field counterpart as the number of molecules is decreased within the smaller focal area. Using the inherent feature of the orientation dipole, the SDOM technique, with its fast imaging speed (at sub-second scale), can be applied to a broad range of fluorescently labeled biological systems to simultaneously resolve the valuable dipole orientation information with super-resolution imaging.

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Objective The objective of the study was to evaluate the effectiveness of telehealth‐based exercise intervention on pain, physical function and quality of life in patients with knee osteoarthritis. Design A systematic review and meta‐analysis of randomised controlled trials (RCTs). Methods Six databases (PubMed, Embase, Cochrane Library, CINAHL, PEDro and Web of Science Core Collection) were searched for relevant randomised controlled trials published from database inception to 3 June 2021. Reviewers independently screened the literature, extracted data and used the Cochrane Collaboration Risk of Bias Tool for quality assessment. A meta‐analysis and subgroup analyses, stratified by control condition, intervention duration and delivery type, were conducted by Revman 5.4. The study was reported in compliance with PRISMA statement. Results A total of 9 independent RCTs with 861 participants were included. The meta‐analysis showed that the telehealth‐based exercise interventions significantly reduced pain in KOA patients (SMD = −0.28, 95% CI [−0.49, −0.08], p < .01) and produced similar effects to controls in terms of physical function and quality of life. Subgroup analysis revealed that telehealth‐based exercise interventions were superior to the use of exercise booklet and usual care in terms of pain and physical function and were similar to face‐to‐face exercise treatment; a long‐term (>3 months) intervention and the use of web and smartphone APPs to deliver exercise interventions were associated with better pain relief and physical function. Conclusions Telehealth‐based exercise intervention is an effective strategy for KOA management during the COVID‐19 epidemic, and it is significantly better than usual care in reducing knee pain and improving physical function and was able to achieve the effects of traditional face‐to‐face exercise treatment. Although the duration and type of delivery associated with the effect of the intervention have been identified, patient preference and acceptability need to be considered in practice.

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