Phase Transition and Luminescent Property Change Induced by Different Organic Cations in One-Dimensional Double Perovskites.

Double perovskites (DPs) have attracted attention in the field of luminescence due to their inherent broadband emission of self-trapping excitons. In this work, we choose [(CH3)3NCH2CHCH2]+ and [CH3CHOHCH2NH2]+ as organic cations to synthesize two new organic-inorganic hybrid DPs, [(CH3)3NCH2CHCH2]2KInCl6 (1) and [CH3CHOHCH2NH2]2KInCl6 (2). The [KCl6]3- and [InCl6]3- octahedra are interchangeably connected by sharing two opposite faces, forming a one-dimensional coordination chain. Each K atom coordinates with six chlorine atoms in 1, while it coordinates with two oxygen atoms in addition to the six chlorine atoms in 2. The coordination between ions K and O in compound 2 may have significantly reduced its luminescence. As a result, compound 1 shows bright-yellow light with a quantum yield of more than 90%, while 2 shows weak blue light with a quantum yield of only 0.98%. In addition, different from no phase transition found in 2, 1 undergoes a reversible phase transition at 324/307 K in the heating-cooling cycle. Through structural and spectral analysis and density functional theory calculation, we conclude that the larger degree of [InCl6]3- octahedral distortion and the larger anion distance (In···In) also cause the PLQY of compound 1 to be higher than that of compound 2.

Predation of Cyclopoid Copepods on the Theronts of Ichthyophthirius multifiliis: Shedding Light on Biocontrol of White Spot Disease.

White spot disease, caused by the parasitic ciliate Ichthyophthirius multifiliis, is a significant threat to the freshwater fish farming industry worldwide, resulting in massive mortality and economic losses. Eliminating the free-swimming theronts from the culture environment is considered crucial for the control of I. multifiliis infection. It is well-documented that planktonic ciliates are valuable food resources for macro-zooplankton in aquatic ecosystems. In this study, we developed a fluorescence labeling method for alive theronts and found that cyclopoid copepods Thermocyclops taihokuensis, Mesocyclops spp., Macrocyclops sp., and Paracyclopina sp. present predation on the theronts in co-culture experiments. Laboratory challenge tests further confirmed that the presence of zooplankton in the culture water body significantly reduced the infection of I. multifiliis in goldfish (p < 0.01). Results from this study revealed that cyclopoid copepods have the potential to be used as biological control agents against white spot disease in aquaculture.

Narrow-band imaging endoscopy with and without magnification in diagnosis of colorectal neoplasia.

AIM: To evaluate the diagnostic efficacies of narrow-band imaging (NBI) endoscopy with and without high magnification in distinguishing neoplasia from non-neoplasia colorectal lesions. METHODS: A total of 118 patients with 123 colorectal lesions examined by NBI endoscopy in the Zhejiang Provincial People's Hospital from September 2008 to April 2010 were enrolled in this study. These lesions were classified by pit pattern and capillary pattern, and then assessed by histopathology. RESULTS: Ten lesions not meeting the diagnostic criteria were excluded, the overall diagnostic accuracy of NBI endoscopy in distinguishing neoplasia from non-neoplasia colorectal lesions was 91.2% (103/113), and that of NBI endoscopy with and without high magnification was 93.0% (40/43) and 90.0% (63/70), respectively. Both were significantly higher than that of conventional colonoscopy reported in the literature (P<0.05), but there was no significant difference between the two groups (P>0.05). CONCLUSION: Besides NBI magnifying endoscopy, NBI endoscopy without magnification may also be used to distinguish neoplasia from non-neoplasia colorectal lesions.