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Abstract The potential of porphyrin derivatives as hole-transporting materials (HTMs) for perovskite solar cells (PSCs) has been demonstrated. The structural engineering of porphyrin HTMs provides an important means for further improvement of the performance of PSCs. Herein, a zinc-porphyrin derivative (ZnP-FL) decorated with four fluorene-terminated triarylamines is presented. The lab synthesis cost of ZnP-FL is estimated to be around $32.2/g. It exhibits good charge-transport ability and thermal stability. A high power conversion efficiency (PCE) of 19.31% is achieved by using ZnP-FL HTM (V oc = 1.08 V; J sc = 24.08 mA · cm−2), which is distinctly higher than that of a control HTM without the fluorene groups (PCE = 17.75%; V oc = 0.97 V; J sc = 24.04 mA · cm−2). This performance enhancement is mainly attributed to the improved open-circuit voltage, which benefits from the stabilized HOMO level of ZnP-FL. In addition, the porphyrin HTM-based PSCs show superior air and thermal stability to the device with the standard HTM spiro-OMeTAD. These results demonstrate that the low-cost and easily accessible porphyrin derivatives are promising HTMs for efficient and stable PSCs.

Background and purpose: Previous studies have shown that human herpes simplex virus (HSV) infection may be associated with the onset of headache or migraine. We aimed to investigate the association between HSV infection and severe headache or migraine. Materials and methods: The cross-sectional data on 5,730 participants aged 20-49 years were obtained from the 1999-2004 National Health and Nutrition Examination Survey (NHANES). We used weighted logistic regression analysis to assess the association between HSV infection (HSV-1 gG-1 and HSV-2 gG-2) and severe headache or migraine, and performed subgroup analyses. Results: Our study found that women, higher education, higher body mass index, better family conditions, smoking and alcohol consumption were all associated with severe headaches or migraines. After adjusting for confounding factors such as sex, age, race, and education, HSV-2 (+) was still significantly associated with severe headache or migraine (OR = 1.22, 95%CI:1.03-1.46, p = 0.0443). In subgroup analyses, we found that participants with HSV-1 (-) and HSV-2 (+) were also significantly associated with severe headache or migraine (OR = 1.41, 95%CI:1.04-1.91, p = 0.0281). Conclusion: HSV-2 gG-2(+) was significantly associated with severe headache or migraine. [ABSTRACT FROM AUTHOR]

The Ag2CrO4/SnO2 n-n type heterojunction has been fabricated by coupling Ag2CrO4 particles with SnO2 nanorods via an in situ synthetic method. The photocatalytic degradation mechanism of the as-prepared heterojunction has also been discussed. Characterization results revealed that the as-fabricated Ag2CrO4/SnO2 composites could reinforce the photo-degradation competencies for rhodamine B dilute solution compared to pure Ag2CrO4 and SnO2 samples. As the increase in the molar ratios of Ag2CrO4-SnO2, the photocatalytic degradation efficiency appeared to the tendency of first increasing and then decreasing. When it was 4:10, in 90 min, the as-obtained samples possessed the vintage photocatalytic degradation efficiency of 95.8% among of pure SnO2, Ag2CrO4 and the as-prepared composites with various molar ratios, respectively. Furthermore, the Ag2CrO4 and SnO2 were connected via chemical bonds to form the homogenous heterojunction. It could boost the separation and transfer of the photogenerated holes and electrons. In addition, the holes, hydroxyl and superoxide radicals played a major role during the photodegradation process. [ABSTRACT FROM AUTHOR]