Three-dimensional imaging of biological cells is crucial for the investigation of cell biology, providing valuable information to reveal the mechanisms behind pathophysiology of cells and tissues. Recent advances in optical diffraction tomography (ODT) have demonstrated the potential for the study of various cells with its unique advantages of quantitative and label-free imaging capability. To provide insight on this rapidly growing field of research and to discuss its applications in biology and medicine, we present the summary of the ODT principle and highlight recent studies utilizing ODT with the emphasis on the applications to the pathophysiology of cells.

Postmenopause is the naturally occurring stage in woman’s life after the permanent cessation of the menstruation longer than 12 months. The transition from the young to the postmenopausal stage impacts the variation in the heart rate. It is important to analyze and detect the variation in Heart Rate Variability (HRV) between young and postmenopausal women in different postures to understand the impact of the age and physical activities on the autonomic health of heart. The aim of this study is to (i) investigate the effect of autonomic regulations of heart rate in young and postmenopausal women in various postures and (ii) determine the possibilities for the reliable, efficient and accurate HRV analysis signal processing algorithm in detecting HRV variations between young and postmenopausal women. The experiments were performed on 25 young women and 25 old women in the postmenopausal phase. Various linear methods have been applied for analysing and detecting HRV variations between young and postmenopausal women. The results concluded that the postmenopausal group showed significantly lower (p < 0.05) values of SDNN, NN50, pNN50, RMSSD, and HRVTi than young group both in the lying and standing postures. These results indicate a decrease in the parasympathetic activity in postmenopausal as compared to the young women due to the age. Further, the performance of linear methods in detecting HRV variations between postmenopausal and young women in different postures was calculated. It is also concluded from the results that HRVi outperforms other HRV analysis methods in detecting HRV variations between postmenopausal and young women.

Background: Inappropriate hair removal increases the risk of surgical site infections which are associated with a higher morbidity and mortality of surgical patients. Here, the effects of a clipping device and a disposable razor on the skin barrier, microbial burden and surface structure were compared. Methods: Changes in bacterial colonization, transepidermal water loss, antioxidant status and the skin surface structure were investigated on the calves of 12 healthy volunteers. Measurement time points were at baseline (t_base) and 24 hours after hair removal (t₂₄). Results: Both, the disposable razor and the clipper showed a decrease in log colony-forming units count from t_base (mean(t_base) ± standard deviation = 2.6 ± 1.27, median ± standard error = 2.6 ± 0.37) to t₂₄ at p_{razo r}= 0.05 and p_clipper = 0.06 respectively. At t₂₄ clipping resulted in a higher reduction of log colony-forming units (mean(t₂₄) = 1.76 ± 0.8, median = 1.69 ± 0.23) compared to the use of the disposable razor (mean(t₂₄) = 1.84 ± 0.85, median = 1.91 ± 0.24). Furthermore, the razor-treated group showed an increase in colony-forming units from t₀ to t₂₄, whereas clipping lead to a continuous decrease in colony-forming units from t₀ to t₂₄. An enhanced appearance of microlesions and a significant increase of transepidermal water loss after shaving using the disposable razor (p = 0.005) were found indicating skin barrier disruptions. Clipping showed no significant effect on transepidermal water loss. Conclusion: Hair removal using the clipping device results in less disruption of the skin barrier compared to the razor, avoiding the development of microlesions. This could be favorable for the prevention of surgical side infections and postoperative wound management.