[en] Objective: To reconstruct the image of inner ear by using 3D-FASE heavily T₂WI, and to establish MRI measurement criterion of inner ear structures. Methods: One hundred and six inner ears of 53 healthy volunteers underwent MRI heavily T2-weighted axial scanning by using 3D fast advanced spin echo sequence. All the original images were transferred to an online workstation. Analyze AVW software was used for image post-processing. All the structures of inner ear were reconstructed, rotated from various angles and measured by using maximum intensity projection (MIP). Results: (1) All the structures of inner ear and internal auditory channel (IAC) could be visualized clearly by using 3D-FASE heavily T₂WI. (2) Using analysis of variance, there was no age, side or race-related difference in inner ear volume, but it was bigger in male than in female [(0.242 ± 0.0236) mm³ (male) versus (0.226 ± 0.021) mm³ (female)]. There was no age, side-related differences in three semicircular canal height and vestibule vertical diameter, but, again, they were bigger in male than in female. The height of upper, lateral and posterior semicircular canal were (5.511 ± 0.626) mm (male) versus (5.167 ± 0.357) mm (female); (3.763 ± 0.495) mm (male) versus (3.446 ± 0.405) mm (female); (5.227 ± 0.547) mm (male) versus (4.786 ± 0.500) mm (female). There was no age, sex or side-related differences in three semicircular canal diameter and cochlea. The diameter of upper, lateral and posterior semicircular canal were (1.06 ± 0.119) mm, (1.14 ± 0.181) mm, and (1.22 ± 0.196)mm; the external diameter of cochlea basal turn was (6.520 ± 0.475) mm, the diameter of cochlea basal turn was (1.413 ± 0.144) mm, and cochlea height was (4.100 ± 0.405) mm. Conclusion: (1) For the first time, the MRI measurement criterion of inner ear structures is established. (2) Vestibule and three semicircular canal of inner ear are bigger in male than in female

[en] This paper reports the doping effect of cholesteric liquid crystal 3 β -Hydroxy-5-cholestene 3-oleate on polymer solar cells composed of the poly 3-hexyl thiophene and the fullerene derivative. With a doping ratio of 0.3 wt%, the device achieves an ideal improvement on the shunt resistor and the fill factor. Compared with the reference cell, the power conversion efficiency of the doped cell is improved 24%. The photoelectric measurement and the active layer characterization indicate that the self-assembly liquid crystal can improve the film crystallization and reduce the membrane defect. (special topic)

[en] Solution-processable hybrid perovskite solar cells offer potential in the photovoltaic field due to their low-cost fabrication and high efficiency. However, an undesirable current–voltage (J-V) hysteresis hampers the applications of perovskite solar cells. In particular, for the inverted device, the understandings for J-V hysteresis origination are not uniform, and the inverted hysteresis phenomenon has been further complicated the hysteresis behavior. In this report, an external bias precondition method is adopted to unveil the origin of the inverted hysteresis. The results indicate that the extents of inverted hysteresis are very much dependent on the bias direction of the precondition. To further unveil the effect of the precondition on inverted hysteresis, the microscopic J-V hysteresis was also observed by using conductive atomic force microscopy (c-AFM) measurements. The results indicate that ion migration and accumulation slowly built up at the grain boundaries of the perovskite film when repeating the scan using c-AFM. Furthermore, the transient characteristics based on capacity-frequency plots and open-circuit voltage decay further identify the presence of difference for the different bias preconditions on the device, because the different bias precondition could induce different directions of ions migration and accumulation. These observations are surprising; it can be further identified that the inverted hysteresis originates from the ionic migration and accumulation, and the grain boundary is as the channel of ionic migration and accumulation. Therefore, the grain boundary plays an important role on the hysteresis effect, and preparation of large-grain or single-crystal perovskite films is the way to reduce the hysteresis effect. (paper)