[Epidemiological characteristics of imported malaria cases in Neijiang City, 2013].

OBJECTIVE: To understand the epidemiological characteristics of imported malaria cases in Neijiang City in 2013, so as to provide the references for malaria elimination in the city. METHODS: The epidemiological data of malaria cases were collected from the Parasitic Diseases Information Management System of Chinese Center for Disease Control and Prevention, and the data were analyzed with the descriptive epidemiological method. RESULTS: Totally 19 cases of imported malaria cases were reported in Neijiang City in 2013, which was increased by 375% comparing to that in 2012 (4 cases) , and all the cases were confirmed by the laboratory. Among these cases, 14 were (73.68%) falciparum malaria cases, 5 (26.32%) were vivax malaria cases; 13 cases (68.42%) were from African countries, and the other 6 (31.58%) were from Southeast Asia. These cases were distributed throughout each quater, which had no significant seasonality. All the cases were male aged from 20-49 years, and the majority of them (16 cases, 84.21%) were farmers and workers. CONCLUSIONS: The prevention and control situation of imported malaria is severe in Neijiang City. The capacity construction of malaria diagnosis and treatment of basic medical institutions as well as the health education and monitoring and management to floating population should be strengthened.

Fluorescence modulation in tribranched switchable [4]rotaxanes.

Two novel tribranched [4]rotaxanes with a 1,3,5-triphenylene core and three rotaxane arms have been designed, synthesized, and characterized by (1)H and (13)C NMR spectroscopies and HR-ESI mass spectrometry. [4]Rotaxanes 1 and 2 each possess the same three-armed skeleton. Each arm incorporates two distinguishable binding sites for a dibenzo[24]crown-8 ring, namely a dibenzylammonium site and an N-methyltriazolium site, and is terminated by a 4-morpholino-naphthalimide fluorophore as a stopper. [4]Rotaxane 1 has three di-ferrocene-functionalized dibenzo[24]crown-8 rings whereas 2 has three simple dibenzo[24]crown-8 rings interlocked with the thread component. Uniform shuttling motions of the three macrocycles in both 1 and 2 can be driven by external acid-base stimuli, which were confirmed by (1)H NMR spectroscopy. However, [4]rotaxanes 1 and 2 show distinct modes of fluorescence modulation in response to external acid-base stimuli. [4]Rotaxane 1 exhibits a remarkable fluorescence decrease in response to the addition of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as a base, which can displace the ferrocene-functionalized macrocycle from the dibenzylammonium station to the N-methyltriazolium station. In contrast, the fluorescence intensity of [4]rotaxane 2 showed an enhancement with the addition of DBU. Time-resolved fluorescence measurements have been performed. The different photoinduced electron-transfer processes responsible for the fluorescence changes in the two molecular systems are discussed. Topological structures of this kind have significant potential for the design and construction of large and complex assemblies with controllable functions.