A phosphorescent multiple emissive layer, in which a blue emissive layer is sandwiched between red and green ones, is employed in a white organic light-emitting device (OLED). This OLED has a maximum luminance of 48000cd∕m2 at 17V, a maximum power efficiency of 9.9lm∕W at 4V, and a color rendering index of 82. In addition, the emission color of this device is fairly stable at high luminances: its Commission Internationale de l′Eclairage coordinate slightly changes from (0.431, 0.436) to (0.400, 0.430) when the luminance ranges from 2000to40000cd∕m2.

Purpose of the studyHypertension is one of the most common comorbidities in COVID-19 pneumonia. However, whether it is an independent factor on the severity and mortality of COVID-19 has not been studied.Study designIn this study, 736 patients with a PCR-confirmed diagnosis of COVID-19 were included from 12 January 2020 to 25 March 2020. All patients were divided into two groups according to whether or not they were hypertensive. After propensity score matching (PSM) to remove the interference of mismatches in the baseline data, the clinical characteristics and outcomes of angiotensin II receptor blocker (ARB)/ACE inhibitors application were analysed.ResultsA total of 220 (29.9%) patients were hypertensive, and 516 (70.1%) patients were not hypertensive. PSM eliminated demographic and comorbidity differences between the two groups. Of all participants, 32 patients died (4.3% mortality), including 17 out of 220 in the hypertension group (7.7%) and 15 out of 516 in the non-hypertension group (2.9%). The incidence of intensive care unit (ICU) stay in the hypertension group (12.8%) was higher than in the non-hypertension group (5.3%) (p<0.05). Logistic regression analysis showed that hypertension was an independent risk factor for death, not other comorbidities. Kaplan-Meier analysis showed that mortality was higher in the hypertension group than in the non-hypertension group before and after PSM (p<0.05). There was no statistically significant difference in ICU therapy, mortality and hospitalisation time between hypertensive patients with or without ARBs/ACE inhibitors (p>0.05).ConclusionHypertension was an independent risk factor for the severity and mortality of patients with COVID-19. ARBs/ACE inhibitors should not be discontinued in hypertensive patients with COVID-19.

Highly bright and efficient blue and white organic light-emitting devices based on oligo(phenylenvinylene) derivatives, 1,4-di(4 -N,Ndiphenylaminostyryl) benzene (DPA-DSB) and 2,5,2 ,5 -tetrastyryl-biphenyl (TSB), are fabricated. In the blue device, using DPA-DSB doped TSB as a blue emitter, due to efficient energy transfer from TSB to DPA-DSB and depression of concentration quenching of the dopant, a maximum brightness of 17 350 cd m −2 and a maximum luminous efficiency of 12.18 cd A −1 are obtained. In the white device, DPA-DSB doped 4,4-N,N -dicarbazolebiphenyl (CBP) acts not only as a blue emitter, but also as a blocking layer to prevent the energy transfer between the two phosphorescent layers in order to balance emissions from the three emissive layers. Combining the blue emission from it with the green and red emissions from the phosphorescent layers, white emission with a maximum brightness of 13 290 cd m −2 and a maximum luminous efficiency of 14.97 cd A −1 is obtained. The colour rendering index of the white device is 79.

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