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Objective: Our aim was to characterise the chronic wound response to autologous adipose-derived stem cells (ADSCs) sheet transplantation. Methods: A pilot descriptive, longitudinal study was performed at the Wound Healing Center of the Vietnam National Burns Hospital from 1 July 2019 to 30 August 2020. Thirty patients with 38 chronic wounds were enrolled in the study and autologous ADSCs sheets were grafted on the wound beds. Wound edges, wound bed, wound size and structure were assessed using histology with ultrastructural changes visualised by transmission electron microscopy. Wounds were assessed at time of transplantation and at the first, second and third week of follow-up. Results: After ADSCs sheet transplantation, improved extracellular matrix (ECM) with neo-vascular structures was observed, and collagen fibres arranged side by side in the dermal layer. Fibroblast proliferation was observed with increased secretion of collagen. Keratinocytes were also observed proliferating and migrating into the epidermis layer. Neo-vascular cells, fibroblast proliferation and collagen production increased weekly however lymphocytes infiltration decreased. Wound size reduced significantly compared to before treatment commenced and wound beds appeared cleaner and filled with granulation tissue. Re-epithelialisation appeared at the wound edge and throughout the wound. Conclusion: ADSCs may have a beneficial effect on cutaneous regeneration and chronic wound healing. [ABSTRACT FROM AUTHOR]

We show analytically and experimentally that direct photodetection of a temporally-stretched and chirped optical pulse-train together with its time-delayed replica can be exploited to realize the generation of tunable continuous-wave microwave signals. The proposed scheme utilizes the chromatic dispersion of the standard single-mode-fiber (SMF) to temporally-stretch and chirp an optical pulse-train in such a way that the pulses overlap with each other. The temporally-stretched pulse-train is then sent to a Mach-Zehnder Interferometer (MZI) where it first splits and then recombines with a time-delayed replica of itself at the output. Proper management of both the dispersion in the system as well as the relative time-delay of the two arms of the MZI enables one to tune the frequency of the generated microwave signal to any integer multiple of the pulse source's repetition frequency which is within the bandwidth of the photodetector. Based on the proposed scheme, using an initial 2 GHz pulse-train, we demonstrate generation of tunable continuous-wave microwave signals from 4 GHz to 14 GHz. [ABSTRACT FROM PUBLISHER]

We report the generation of dual amplitude pulses in an active mode-locked fiber laser within a birefringent cavity. Different to normal mode-locked pulses with identical amplitude and polarization state, and pulses polarized on both x- and y-axes simultaneously exist in the output pulse train. The two orthogonal pulse sequences have different amplitudes and lase at different wavelengths. Dual wavelengths are the result of red shift and blue shift of the x- and y-polarization states of the generated pulses, respectively, due to the detuning phenomena. Locking to individual x- or y-polarized pulse is also obtained by adjusting polarization controllers [ABSTRACT FROM PUBLISHER]

Our aim is to characterize chronic wound response to autologous adipose-derived stem cell (ADSC) sheet transplantation. A pilot descriptive longitudinal study was conducted at the Wound Healing Center of the Vietnam National Burn Hospital from July 1, 2019 to August 30, 2020. Thirty patients with 38 chronic wounds were enrolled in the study and were grafted with autologous ADSC sheets on the wound bed. Wound edges, wound bed, wound size and structure using H&E staining, ultrastructure changes by transmission electron microscope at the time of transplantation and at the first, second and third week of follow-up were observed. Results indicated that after ADSC sheet transplantation, the structure and ultrastructure of chronic wounds had improved. The extracellular matrix (ECM), neo-vascular, fibroblast and collagen fibers proliferated and arranged side by side at the dermis layer. Fibroblast proliferated and increased secretion of collagen. Keratinocytes proliferated and immigrated in the epidermis layer. After three weeks of autologous ADSC sheet transplantation, epithelial cells covered 90% of the wound surface. Neo-vascular, fibroblast and collagen proliferation increased weekly. The image of lymphocyte infiltration in connective tissues decreased. Wound size reduced significantly compared to before the experiment, wound beds were cleaner and filled with granulation tissue. Re-epithelialization appeared at the wound edge and throughout the wound. Wound measurements were statistically significant at the second and third weeks after starting treatment (week 2: 12.8±11.56 cm2 [range: 1-47.42 cm2], p<0.05; week 3: 7.44 ± 5.68 cm2 [range: 0.45- 20.10 cm2], p<0.001), indicating autologous ADSC treatment enhanced healing of chronic wounds. In conclusion, ADSCs have a beneficial effect on cutaneous regeneration and chronic wound healing., (Copyright © 2021 Euro-Mediterranean Council for Burns and Fire Disasters.)