Octahedral Distortion and Displacement-Type Ferroelectricity with Switchable Photovoltaic Effect in a 3d^{3}-Electron Perovskite System

Because of the half-filled t_{2g}-electron configuration, the BO_{6} octahedral distortion in a 3d^{3} perovskite system is usually very limited. In this Letter, a perovskitelike oxide Hg_{0.75}Pb_{0.25}MnO_{3} (HPMO) with a 3d^{3} Mn^{4+} state was synthesized by using high pressure and high temperature methods. This compound exhibits an unusually large octahedral distortion enhanced by approximately 2 orders of magnitude compared with that observed in other 3d^{3} perovskite systems like RCr^{3+}O_{3} (R=rare earth). Essentially different from centrosymmetric HgMnO_{3} and PbMnO_{3}, the A-site doped HPMO presents a polar crystal structure with the space group Ama2 and a substantial spontaneous electric polarization (26.5  μC/cm^{2} in theory) arising from the off-center displacements of A- and B-site ions. More interestingly, a prominent net photocurrent and switchable photovoltaic effect with a sustainable photoresponse were observed in the current polycrystalline HPMO. This Letter provides an exceptional d^{3} material system which shows unusually large octahedral distortion and displacement-type ferroelectricity violating the "d^{0}-ness" rule.

[Vigilance against a highly lethal insecticide chlorfenapyr poisoning (report of 4 cases and literature review)]

In order to improve the clinical attention to the poisoning of chlorfenapyr, the diagnosis and treatment strategy of chlorfenapyr poisoning were discussed. This paper collected 4 cases of chlorfenapyr in the emergency department of the Second Hospital of Hebei Medical University and 4 cases of literature review, summarized the clinical characteristics of pesticide poisoning cases containing chlorfenapyr in China, and summarized and analyzed the clinical data of the cases. Seven of the 8 patients died from poisoning by chlorfenapyr. Exposure to chlorfenapyr through respiratory tract and digestive tract showed high mortality. Fever, hyperhidrosis, elevated muscle enzymes and progressive central nerve damage were its prominent clinical characteristics. Most of the initial symptoms of exposure were not serious. Some patients, especially those with low exposure dose, had a relatively stable stage with or without clinical diagnosis and treatment. In case of sweating, obvious fever and disturbance of consciousness, the condition would deteriorate rapidly, respiratory and circulatory failure and eventually die. With the increase of production capacity and market launch, people have more opportunities to be exposed to chlorfenapyr. It is urgent to strengthen the basic and clinical research of chlorfenapyr poisoning; Attention should be paid to the observation and treatment in the initial stable stage of poisoning, which can be used as a reference for the treatment of oxidative phosphoric acid dissolving coupling agent (sodium pentachlorophenol) poisoning.

[An analysis of coping styles and subjective well-being among nurses in the emergency treatment room of grade A tertiary hospitals in a province of China]

Objective: To investigate the coping styles and subjective well-being of nurses in the emergency treatment room of grade A tertiary hospitals in a province of China, and to explore the relationship between coping styles and subjective well-being. Methods: In January 2016, 189 nurses in the emergency treatment room were selected from 9 grade A tertiary hospitals in a province of China by random sampling. The general data, coping styles, and subjective well-being of these nurses were analyzed using the general questionnaire, coping style questionnaire, and Campbell index of well-being scale, respectively. Results: The total score of subjective well-being of nurses in the emergency treatment room was 7.54, and the subjective well-being was significantly different between the nurses with different professional titles and between those with different education levels (F=3.46 and 3.47, both P<0.05). The score of illusion coping style differed significantly across the nurses of different ages (F=5.17, P<0.05) , the scores of self-reproach, illusion, and withdrawal coping styles differed significantly across the nurses with different nursing years (F=3.99, 5.30, and 4.97, all P<0.05) , and the score of illusion coping style differed significantly across the nurses with different education levels (F=5.09, P<0.05). Most (71.9%) of the nurses in the emergency treatment room adopted the mature coping style. Subjective well-being was positively correlated with problem-solving, help-seeking, and rationalization (r=0.232, 0.018, and 0.167, all P<0.05) and negatively correlated with withdrawal (r=-0.146, P<0.05) . Conclusion: Most nurses in the emergency treatment room adopt the mature coping style. Their subjective well-being and coping style vary with different ages, nursing years, professional titles, and education levels, and the subjective well-being is relatively low.

Efficient perovskite solar cells via simple interfacial modification toward a mesoporous TiO2 electron transportation layer

Enhanced performance of a perovskite solar cell via simple interfacial modification onto a mesoporous TiO₂ layer.