Highly Horizontal Oriented Tricomponent Exciplex Host with Multiple Reverse Intersystem Crossing Channels for High-Performance Narrowband Electroluminescence and Eye-Protection White Organic Light-Emitting Diodes.

Despite multiple-resonance thermally activated delayed fluorescence (MR-TADF) emitters with small full-width at half maximum are attractive for wide color-gamut display and eye-protection lighting applications, their inefficient reverse intersystem crossing (RISC) process and long exciton lifetime induce serious efficiency roll-off, which significantly limits their development. Herein, a novel device concept of building highly efficient tricomponent exciplex with multiple RISC channels is proposed to realize reduced exciton quenching and enhanced upconversion of nonradiative triplet excitons, and subsequently used as a host for high-performance MR-TADF organic light-emitting diodes (OLEDs). Compared with traditional binary exciplex, the tricomponent exciplex exhibits obviously improved photoluminescence quantum yield, emitting dipole orientation and RISC rate constant, and a record-breaking external quantum efficiency (EQE) of 30.4% is achieved for tricomponent exciplex p-PhBCzPh: PO-T2T: DspiroAc-TRZ (50: 20: 30) based OLED. Remarkably, maximum EQEs of 36.2% and 40.3% and ultralow efficiency roll-off with EQEs of 26.1% and 30.0% at 1000 cd m-2 are respectively achieved for its sky-blue and pure-green MR-TADF doped OLEDs. Additionally, the blue emission unit hosted by tricomponent exciplex is combined with an orange-red TADF emission unit to achieve a double-emission-layer blue-hazard-free warm white OLED with an EQEmax of 30.3% and stable electroluminescence spectra over a wide brightness range.

Hepatitis E outbreak in a mechanical factory in Qingdao City, China.

OBJECTIVE: In July 2018, recurrent hepatitis E cases were reported from a factory in Qingdao City, China. The aim of this study was to identify additional cases, and help prevent future incidents by identifying possible risk factors for infection. METHODS: Participants were asked to provide blood samples for hepatitis E virus (HEV) IgM and IgG antibodies screening, as well as liver function test. A questionnaire that assessed demographics, potential risk factors, and clinical symptoms was completed by participants. HEV RNA genotyping was performed using a nested Reverse Transcriptional Polymerase Chain Reaction (RT-PCR) method. Adjusted Poisson regression model for participant characteristics and risk factors was constructed for multivariate analysis. RESULTS: Overall, 41(14.5%, 41/283) participants had recent acute infection (21 of these were symptomatic). The result of multivariate analysis demonstrated a significant association of acute HEV infection with consumption of pig liver within the past two months (Relative Risk 2.61, 95% confidence interval (CI) 1.10-6.17, p=0.0294). Sequencing of HEV RNA from seventeen acute cases indicated three HEV isolates of genotype 4 induced this outbreak. CONCLUSIONS: This was probably a common-source foodborne hepatitis E outbreak, related to the consumption of undercooked pig liver.

Sexually transmitted infection prevalence and related risk factors among heterosexual male methamphetamine users in China.

Few studies have examined the association between methamphetamine (MA) abuse and sexually transmitted infection (STI) risk among heterosexual male MA users in China. A total of 288 heterosexual male MA users who met our inclusion criteria were recruited from nightclubs, KTVs, bars, bath centres and an STI clinic. STIs were screened among the participants, and the risk factors related to STIs were analysed by multivariate logistic regression in SPSS 11.0. Among the 288 heterosexual male MA users, 51 (17.7%) had syphilis, 36 (12.5%) had genital warts, 2 (0.7%) had genital herpes, 3 (1.0%) had HIV infection and 41 (14.2%) had urethritis. STIs were associated with the following variates: 'MA has the function of anti-inebriation' (OR = 2.522, 95%CI = 1.337-4.756), 'I am addicted to MA' (OR = 4.030, 95%CI = 2.194-7.401), 'It occurred to me to abstain from MA' (OR = 2.939, 95%CI = 1.246-6.934), 'Years of MA abuse' (OR = 2.622, 95%CI = 1.318-5.215), 'Times of MA abuse per week' (OR = 5.275, 95%CI = 1.988-14.002), 'Number of persons using MA together' (OR = 2.579, 95%CI = 1.246-5.340) and 'Number of female sex workers as sex partners per MA abuse' (OR = 4.004, 95%CI = 1.526-10.508). Our findings show that MA users belong to the high-risk group for STI in China. STIs, except for HIV, have spread widely among heterosexual male MA users. Thus, specific interventions must be conducted to prevent the spread of STIs in this population in China.