Highly Efficient Thermally Activated Delayed Fluorescence via an Unconjugated Donor-Acceptor System Realizing EQE of Over 30.

In this work, two novel thermally activated delayed fluorescence (TADF) emitters, 2tDMG and 3tDMG, are synthesized for high-efficiency organic light-emitting diodes (OLEDs), The two emitters have a tilted face-to-face alignment of donor (D)/acceptor (A) units presenting intramolecular noncovalent interactions. The two TADF materials are deposited either by an evaporation-process or by a solution-process, both of them leading to high OLED performance. 2tDMG used as the emitter in evaporation-processed OLEDs achieves a high external quantum efficiency (EQE) of 30.8% with a very flat efficiency roll-off of 7% at 1000 cd m-2 . The solution-processed OLEDs also display an interesting EQE of 16.2%. 3tDMG shows improved solubility and solution processability as compared to 2tDMG, and thus a high EQE of 20.2% in solution-processed OLEDs is recorded. The corresponding evaporation-processed OLEDs also reach a reasonably high EQE of 26.3%. Encouragingly, this work provides a novel strategy to address the imperious demands for OLEDs with high EQE and low roll-off.

CD19+CD24hiCD38hiBregs involved in downregulate helper T cells and upregulate regulatory T cells in gastric cancer.

Regulatory B cells (Bregs) play a critical role in inflammation and autoimmune disease. We characterized the role of Bregs in the progression of gastric cancer. We detected an increase in Bregs producing IL-10 both in peripheral blood mononuclear cells (PBMCs) and in gastric tumors. Multicolor flow cytometry analysis revealed that a subset of CD19+CD24hiCD38hi B cells produces IL-10. Functional studies indicated that increased Bregs do not inhibit the proliferation of CD3+T cells or CD4+ helper T cells (Th cells). However, Bregs do suppress the secretion of IFN-γ and TNF-α by CD4+Th cells. CD19+CD24hiCD38hiBregs were also found to correlate positively with CD4+FoxP3+ regulatory T cells (Tregs). Neutralization experiments showed that Bregs convert CD4+CD25- effector T cells to CD4+FoxP3+Tregs via TGF-ß1. Collectively, these findings demonstrate that increased Bregs play a immunosuppressive role in gastric cancer by inhibiting T cells cytokines as well as conversion to Tregs. These results may provide new clues about the underlying mechanisms of immune escape in gastric cancer.

Epigenetically downregulated Semaphorin 3E contributes to gastric cancer.

Axon guidance protein Semaphorin 3E (Sema3E) promotes tumor metastasis and suppresses tumor cell death. Here, we demonstrated that Sema3E was decreased in gastric cancer. Its levels were inversely associated with tumor progression. Levels of Sema3E were associated with low p300 and high class I histone deacetylase (class I HDAC). Ectopic expression of Sema3E inhibited proliferation and colony formation of gastric cancer cell lines in vitro and xenografts in vivo. Sema3E overexpression inhibited migration and invasion of gastric cancer cells, which was associated with induction of E-cadherin and reduction of Akt and ERK1/2 phosphorylation. We suggest that silencing of Sema3E contributes to the pathogenesis of gastric cancer.

Vitamin D deficiency contributes to the reduction and impaired function of naïve CD45RA⁺ regulatory T cell in chronic heart failure.

The effect of vitamin D pertinent to cardiovascular health on the heart itself is considered to shift toward an anti-inflammatory response in chronic heart failure (CHF); however, its underlying mechanism is not completely understood. In this study, we demonstrated that plasma 25(OH)D level, negatively associated with NT-ProBNP, correlated with the decreased Treg in CHF compared to the patients with other cardiovascular diseases and healthy and older donors. Naïve Treg cell (CD4(+)CD45RA(+)Foxp3(lo)T) subset, rather than whole Treg cells, contributes to the reduction of Treg in CHF. 1,25(OH)2D treatment maintained partial expression of CD45RA on CD4(+)T cell after αCD3/CD28 monoclonal antibodies activation and ameliorated the impaired CD4(+)CD45RA(+)T cell function from CHF patients through upregulating Foxp3 expression and IL-10 secretion in vitro. Low level of vitamin D receptor (VDR) was detected in CD4(+)CD45RA(+)T cell of CHF than control, while 1,25(OH)2D treatment increased the VDR expression to exert its immunosuppression on T cell. The results of this study might provide tangible evidence to our knowledge of the impact of vitamin D supplementation on naïve Tregs, which may offer new means of preventing and treating CHF.

A 3-dimensional spiro-functionalized platinum(II) complex to suppress intermolecular π-π and Pt···Pt supramolecular interactions for a high-performance electrophosphorescent device.

A 3-D platinum(II)-based spirometal complex has been designed and synthesized to suppress aggregation and excimer emission. A prototype phosphorescent organic light-emitting device exhibits the high-performance orange emission with an external quantum efficiency of up to 5.2%.

Conjugated asymmetric donor-substituted 1,3,5-triazines: new host materials for blue phosphorescent organic light-emitting diodes.

Conjugated asymmetric donor-substituted 1,3,5-triazines (ADTs) have been synthesized by nucleophilic substitution of organolithium catalyzed by [Pd(PPh(3))(4)]. Theoretical and experimental investigations show that ADTs possess high solubility and thermostability, high fluorescent quantum yield (35%), low HOMO (-6.0 eV) and LUMO (-2.8 eV), and high triplet energy (E(T), 3.0 eV) according to the different substitution pattern of triazine. The application as host materials for blue PHOLEDs yielded a maximum current efficiency of 20.9 cd A(-1), a maximum external quantum efficiency of 9.8%, and a brightness of 9671 cd m(-2) at 5.4 V, making ADTs good candidates for optoelectronic devices.

Fas Ligand gene transfer enhances the survival of tissue-engineered chondrocyte allografts in mini-pigs.

BACKGROUND AND PURPOSE: Since the Fas/Fas Ligand (FasL) interaction has been recognized as an apoptotic pathway, it eliminates the activated T cells and promotes the survival of grafts. In this study, the effect of FasL transfection of pig chondrocytes on allogeneic transplantation was examined in vitro and in vivo. METHODS: Chondrocytes were isolated from articular and aural cartilages of anesthetized Guizhou Xiang (Gz) pig. The cells were transfected with G418 selected virus, packed from PA317 cells with a constructed plasmid using pig FasL (pGCEN-FasL). The apoptotic effect of FasL transfection was examined on Jurkat cells and activated recipient Gz T cells. The FasL expression was assessed by Western blot and flow cytometry. FasL+chondrocytes-Pluronic F-127 complex was injected into the right abdomen of recipient Gz pig. Histology and morphology of the engineered tissue were examined after 2 and 5 weeks of transplantation. RESULTS: The FasL expression was confirmed in pGCEN-FasL transfected chondrocytes. The expression of FasL of chondrocytes from Gz pig was analyzed by FACS. The apoptosis of Jurkat cells and activated recipient Gz T cells was increased by co-culture with FasL(+) chondrocytes (53.41% and 30.38% (E/T=10:1), in contrast of 32.27% and 13.16% with the control chondrocytes, respectively, P<0.01). FasL(+) chondrocytes-Pluronic F-127 implant expressed FasL and Type II collagen at the 5th week and survived until the 8th week. INTERPRETATION: The result indicates that the expression of FasL by chondrocytes is capable of inducing apoptosis of activated T cells. This suggests a potential role for allogeneic transplantation with chondrocytes.