Pressure-induced luminescence evolution of 3,3'-diamino-4,4'-azofurazan: Role of restricting chemical bond vibration and conformational modification.

The luminescence and electronic structure of 3,3'-Diamino-4,4'-azofurazan (DAAzF) were studied under high pressure conditions through experimental and calculation approaches. The transition of π* â†’ π was primarily responsible for DAAzF's broad light emission. Upon applying pressure to DAAzF, high-pressure-stiffened hydrogen-bond interactions enable the restriction of the stretching vibration of NH2 group. The reduced energy loss through nonradiative rotational relaxation and molecular motions lead to a ∼20 times luminescent enhancement of DAAzF from 1 atm to 8.9 GPa. With the further strengthening of interlayer hydrogen bond interactions at higher pressure, the deviation of hydrogen atoms in amino groups from the molecular plane lessens the radiation transition efficiency. In addition, the bending of the C-C-N=N bond further leads to molecular conformation changes at approximately 20.7 GPa, which induces an abrupt redshift and moderate quenching of the luminescence. Furthermore, the band gap of DAAzF is significantly influenced by pressure. As the color undergoes a transition from yellow to red, and becomes darker as the pressure increases, the absorption edge shifted towards red. At 3.4, 9, and 21 GPa, three conformational variations were identified in conjunction with electronic structural alterations.

CD4+CD25+ regulatory T cells decreased future liver remnant after associating liver partition and portal vein ligation for staged hepatectomy.

BACKGROUND: Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is an innovative surgical approach for the treatment of massive hepatocellular carcinoma (HCC), the key to successful planned stage 2 ALPPS is future liver remnant (FLR) volume growth, but the exact mechanism has not been elucidated. The correlation between regulatory T cells (Tregs) and postoperative FLR regeneration has not been reported. AIM: To investigate the effect of CD4+CD25+ Tregs on FLR regeneration after ALPPS. METHODS: Clinical data and specimens were collected from 37 patients who developed massive HCC treated with ALPPS. Flow cytometry was performed to detect changes in the proportion of CD4+CD25+ Tregs to CD4+ T cells in peripheral blood before and after ALPPS. To analyze the relationship between peripheral blood CD4+CD25+ Treg proportion and clinicopathological information and liver volume. RESULTS: The postoperative CD4+CD25+ Treg proportion in stage 1 ALPPS was negatively correlated with the amount of proliferation volume, proliferation rate, and kinetic growth rate (KGR) of the FLR after stage 1 ALPPS. Patients with low Treg proportion had significantly higher KGR than those with high Treg proportion (P = 0.006); patients with high Treg proportion had more severe postoperative pathological liver fibrosis than those with low Treg proportion (P = 0.043). The area under the receiver operating characteristic curve between the percentage of Tregs and proliferation volume, proliferation rate, and KGR were all greater than 0.70. CONCLUSION: CD4+CD25+ Tregs in the peripheral blood of patients with massive HCC at stage 1 ALPPS were negatively correlated with indicators of FLR regeneration after stage 1 ALPPS and may influence the degree of fibrosis in patients' livers. Treg percentage was highly accurate in predicting the FLR regeneration after stage 1 ALPPS.