Multi-Resonant Indolo[3,2,1-jk]carbazole-Based Host for Blue Phosphorescent Organic Light-Emitting Diodes.

In organic light-emitting diodes, positive and negative charge carriers mostly migrate at different rates. This could result in excitons formed in the EML often migrating to the vicinity of the hole transport layer and the electron transport layer. To address this, it is important to design high-quality multi-resonance hosts that can balance the migration rate of carriers. Here, we report two newly developed multi-resonance hosts, m-ICzPBI and o-ICzPBI. The hosts contain an indolo[3,2,1-jk]carbazole (ICz) motif, which functionalized as either a donor or an acceptor unit. The hosts exhibit extremely high molecular rigidity and thermal stability. Devices A and B were constructed using FIrpic as a phosphorescent emitter with m-ICzPBI or o-ICzPBI as a host. Device A achieved high maximum values of EQE, PE and CE of 13.4%, 24.8 lm W-1 and 31.6 cd A-1, respectively, and low efficiency roll-off at 5000 cd m-2 of 8.6%, 10.6 lm W-1 and 20.3 cd A-1, respectively.

Energy Level, Crystal Morphology and Fluorescence Emission Tuning in Cocrystals via Molecular-Level Engineering.

Organic donor-acceptor complexes as new organic semiconductor class have attracted wide attention, due to their potential applications in functional optoelectronics. Herein, we present two new charge transfer cocrystals of di-cyanodiazafluorene -perylene (DCPE) and di-cyanodiazaflfluorene-pyrene (DCPY) through a rational cocrystal-engineering strategy. Although they are both 1 : 1 mixed stacking cocrystals with similar chemical structures, the DCPE cocrystal possesses a non-centrosymmetric space group and narrower band gap compared to DCPY cocrystal, because of the non-covalent bonding variation. The electrostatic potential accumulated in the lateral facets leads to highly twisted DCPE nanobelts, and the small band gap causes near infrared fluorescence. Meanwhile, the DCPY crystals with centrosymmetric space groups and weaker intermolecular interactions exhibited an untwisted morphology and red emission. This study will be helpful for the design and understanding of functional cocrystal materials that can be used in flexible micro/nano-mechanics, mechanical energy, and optical devices.

Role of scalp hypothermia in patients undergoing minimally invasive evacuation of hypertensive cerebral hemorrhage.

OBJECTIVE: Hypertensive intracerebral hemorrhage (HICH) is one of the common multiple diseases in neurology. Patients with severe HICH have high risk of disability and poor prognosis. METHODS: In order to explore the clinical effect of mild hypothermia combined with micro-traumatic evacuation of cerebral hemorrhage in the treatment of severe HICH, 136 patients with severe HICH were selected and divided into control group and study group using random number table method, 68 each group. The control group was treated with micro-traumatic evacuation of cerebral hemorrhage on the basis of conventional symptomatic treatment, while the study group was treated with mild hypothermia combined with micro-traumatic evacuation of cerebral hemorrhage on the basis of conventional symptomatic treatment. After treatment, the two groups were followed up for eight weeks. RESULTS: The overall effective rate, residual hematoma volume, rebleeding rate, National Institute of Health stroke scale (NIHSS) score, Barthel index score and incidence of adverse reactions after treatment were observed and compared. The overall effective rate of the study group was 89.7%, which was significantly higher than that of the control group (67.6%). The mortality rate of the study group was 3.0%, which was significantly lower than that of the control group (14.7%, P<0.05). The residual hematoma volume and rebleeding rate of the study group were significantly lower than those of the control group (P<0.05). Before treatment, the NIHSS score and Barthel index score of the two groups had no significant differences (P>0.05). After treatment, they were improved, and the improvement of the study group was more significant (P<0.05). The incidence of adverse reactions in the study group was 10.0%, which was significantly lower than that in the control group (36.0%, P<0.05). CONCLUSION: Mild hypothermia in combination with micro-traumatic evacuation of cerebral hemorrhage has significant clinical effect in the treatment of severe HICH. It can significantly improve neurological function and quality of life, causing few adverse reactions. Its clinical application value is high.

Correlation between miR-23a and onset of hepatocellular carcinoma.

BACKGROUND AND AIMS: To clarify the role of miR-23a in the onset and development of hepatocarcinoma on the cellular, genetic and molecular levels. PATIENTS AND METHODS: Seventy-eight patients were included after hepatectomy. Relationships between the clinical pathological factors of tumor and paracancerous tissues were analyzed. Risk factors of overall and recurrence-free survival rates were subject to multi-variable analysis. Tissues were sequenced by digital miRNA expression profiling, and new miRNA was subject to target gene prediction. RESULTS: miR-23a expression was correlated with the stage of the TNM Classification of Malignant Tumours most significantly, followed by tumor size (P=0.041 and 0.047). High miR-23a, vascular invasion, tumor size≥7cm, tumor capsule and late pathological stage were the risk factors of overall survival rate, and those of recurrence-free survival rate also included alpha-fetoprotein level≥200µg/L and multiple tumors. Compared with normal hepatic cell line L-02, the miR-23a expression levels in tumor cell lines SMMC-7721 and HepG2 were up-regulated and down-regulated respectively. Transfecting miR-23a inhibitor suppressed cell growth. Apoptotic rates of the control and those transfected with inhibitor-NC and miR-23a inhibitor for 48h were similar. CONCLUSION: High miR-23a expression is the independent prognostic factor of overall and recurrence-free survival rates, and miR-23a may be involved in the onset of hepatocarcinoma as an oncogene.