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A pre-embedding mixed A-cation halide strategy is developed to eliminate the residual unstable PbI2 and lattice strain near the buried interface of the perovskite layer for the stability improvement of formamidinium-based perovskite solar cells.

We investigate the finite-time performance of a quantum endoreversible Carnot engine cycle and its inverse operation — Carnot refrigeration cycle, employing a spin-1/2 system as the working substance. The thermal machine is alternatively driven by a hot boson bath of inverse temperature β h and a cold boson bath at inverse temperature β c (>β h). While for the engine model the hot bath is constructed to be squeezed, in the refrigeration cycle the cold bath is established to be squeezed, with squeezing parameter r. We obtain the analytical expressions for both efficiency and power in heat engines and for coefficient of performance and cooling rate in refrigerators. We find that, in the high-temperature limit, the efficiency at maximum power is bounded by the analytical value η + = 1 − sech ( 2 r ) ( 1 − η C ) , and the coefficient of performance at the maximum figure of merit is limited by ε + = sech ( 2 r ) ( 1 + ε C ) sech ( 2 r ) ( 1 + ε C ) − ε C − 1 , where η C = 1 – β h/β c and ε C = β h/(β c – β h) are the respective Carnot values of the engines and refrigerators. These analytical results are identical to those obtained from the Carnot engines based on harmonic systems, indicating that the efficiency at maximum power and coefficient at maximum figure of merit are independent of the working substance.

Hypertrophic scar (HS) is a fibroproliferative disorder that causes cosmetic as well as functional problems; however, to our knowledge, there is no satisfactory treatment for HS to date. Previous studies have indicated that angiogenesis plays a crucial role in HS formation; therefore, anti-angiogenetic therapies are considered effective in improving HS. Although tacrolimus (TAC) has been proven effective in preventing HS formation in vivo and in vitro, its underlying mechanism remains controversial and ambiguous. Because of its anti-angiogenic effects in other diseases, we aimed to determine whether TAC reduces HS by suppressing angiogenesis. Using a rabbit ear HS model that we developed, HS was treated once a week with normal saline, dimethyl sulfoxide, or TAC for 3 weeks. Histological evaluation indicated that TAC significantly reduced collagen deposition and microvessel density in scar tissues. Moreover, immunofluorescence staining for CD31 and vascular endothelial growth factor (VEGF)-A revealed that TAC significantly inhibited HS angiogenesis. In vitro analysis showed that TAC inhibited endothelial cell migration and tubulogenesis as well as the viability and proliferation of human umbilical vascular endothelial cells (HUVECs) and HS fibroblasts (HSFBs). Furthermore, TAC significantly downregulated the expression of the human angiogenetic factors VEGF-A, FGF-2, PDGF-β, and TGF-β1 in HUVECs and HSFBs. Additionally, TAC-mediated inhibition of angiogenesis decreased the gene expression of crucial fibrotic markers, including α- smooth muscle actin and collagens 1 and 3, in HSFBs. This is the first study to demonstrate the inhibitory effects of TAC on HS formation mediated by a mechanism involving the suppression of scar angiogenesis.

OBJECTIVE The purpose of this study was to detect the yield, activity and safety of the stromal vascular fraction (SVF) isolated by a new clinical-grade collagenase with a specific process and to validate the efficacy of the method. MATERIALS AND METHODS For the in vitro study, adipose tissue specimens were obtained from women undergoing elective liposuction (n = 5). The SVF was isolated by new clinical-grade collagenase for the experimental group and research-grade collagenase NB4 for the control group. The surface markers of the SVFs isolated by the two collagenases were detected by flow cytometry. The yield, activity and morphology of the SVFs were compared, together with their proliferation, migration and differentiation. Furthermore, we conducted a clinical trial to evaluate the improvement of skin texture after transplantation of autologous SVF isolated by clinical-grade collagenase. RESULTS There were no statistically significant differences in the yield, viability or morphology of the SVFs isolated by the new collagenase and collagenase NB4. Adipose tissue-derived mesenchymal stem cells (ASCs) surface marker expression was consistent between the two products. The differentiation potential of the cells was not different, which was consistent with previously published results. The SVF isolated by the new collagenase had a higher proliferation and migration. After administration of autologous SVF isolated by the new collagenase, the VISIA score improved significantly with regard to wrinkle scores and texture scores. CONCLUSION We concluded that this new type of clinical-grade collagenase can replace current research-grade products without any negative effect on the yield or function of the SVF, which can be applied to antiaging and rejuvenation of facial skin.

We consider a quantum endoreversible Carnot engine cycle and its inverse operation–Carnot refrigeration cycle, working between a hot bath of inverse temperature [Formula: see text] and a cold bath at inverse temperature [Formula: see text]. For the engine model, the hot bath is constructed to be squeezed, whereas for the refrigeration cycle, the cold bath is set to be squeezed. In the high-temperature limit, we analyze efficiency at maximum power and coefficient of performance at maximum figure of merit, revealing the effects of the times allocated to two thermal-contact and two adiabatic processes on the machine performance. We show that, when the total time spent along the two adiabatic processes is negligible, the efficiency at maximum power reaches its upper bound, which can be analytically expressed in terms of squeezing parameter [Formula: see text]: [Formula: see text], with the Carnot efficiency [Formula: see text] and the coefficient of performance at maximum figure of merit is bounded from the upper side by the analytical function: [Formula: see text], where [Formula: see text].