[Investigation on contamination of Giardia and Cryptosporidium in drinking water in Jiangsu Province].

Objective To know the contamination status of Giardia lamblia and Cryptosporidium in drinking water of Jiangsu Province, so as to provide the evidence for producing hygiene and safety drinking water. Methods A total of 28 water plants of 13 cities in Jiangsu Province were selected, and the source water (10 L), chlorinated water (100 L) and tap water (100 L) were collected separately in each site. The water samples were then treated by filtration, washing, centrifuging concentration, immune magnetic separation, and immunofluorescent assay, to detect the numbers of Giardia cysts and Cryptosporidium oocysts. Results Totally 84 samples from 13 cities were collected, including 28 source water, 28 chlorinated water and 28 tap water samples. Among the chlorinated water and tap water samples, no Giardia cysts and Cryptosporidium oocysts were found. However, Giardia cysts were detected in 3 (10.71%, 3/28) source water samples (Yancheng, Lianyungang, Changzhou cities), with the density of 1 cyst/10 L of all. Cryptosporidium oocysts were also detected in 3 (10.71%, 3/28) source water samples (Nanjing, Zhenjiang, Yangzhou cities), with the density of 1 oocyst/10 L of all. Conclusions The source water in partial areas of Jiangsu Province has been contaminated by Giardia and Cryptosporidium. To ensure the safety of drinking, the regulation of source water and surveillance of drinking water should be strengthened.

[Diagnostic knowledge and skills of parasitic diseases based on competition of professional personnel in Jiangsu Province, China].

Objective To understand the integrated ability of parasitic disease prevention and control of professional personnel of Jiangsu Province through the contest. Methods Totally 56 players from the whole province were selected, and all the players participated in the contest. The theory knowledge and skill scores were collected and the statistical analyses were conducted. Results The average theoretical score of the participants was 88.86±15.56 and the passing rate was 91.1%. The average skill operating score was 69.16±16.01 and the passing rate was 67.9%. The average Plasmodium microscopy score was 16.54±8.09 and the passing rate was 50%. The average helminth egg microscopy score was 34.27±10.66 and the passing rate was 67.9%. There were statistical differences among the age groups and different levels of schistosomiasis endemic situation (F = 5.10, 6.39, both P < 0.01). The theoretical knowledge including schistosomiasis, malaria, hydatid disease and others and the score rates were 91.07%, 90.94%, 85.83% and 90.93%, respectively. The hydatid disease score rate was lower (χ2 = 19.17, P < 0.01). The radar chart displayed that the score rates of tabletting and microscopy test in Kato-Katz film production, malaria blood film production and microscopy test were all low. Conclusion In Jiangsu Province, the participants have higher score in the theory test. However, they have lower skill test score, especially in the parasite species identification. The operational skills still need to be strengthened for center for disease control (CDC) participants.

Luminescent properties of BaAl12O19:Tb, Dy phosphors prepared by sol-gel method.

BaAl12O19:Tb, Dy phosphor was prepared by the sol-gel technique using citric acid as a complextant. XRD was used to characterize the relevant crystallization behavior of the phosphor. The luminescence properties and energy transfer between Tb3+ and Dy3+ were investigated. The results revealed that energy transfer exists between Dy3+ and Tb3+ at appropriate Tb3+ concentrations. The emission intensity of Tb3+ increases and energy transfer happens from Dy3+ to Tb3+ ions at the higher content of Tb3+ when Tb3+ and Dy3+ ions were co-doped. BaAl12O19 phosphors doped with Tb3+ or Dy3+ ions only were studied to compared with BaAl12O19:Tb, Dy phosphors. The results showed that the maximum excitation peak of BaAl12O19:Tb is 240 nm and the emission spectrum consists of four peaks at 490, 545, 590, and 625 nm, originating from 5D4 --> 7FJ (J = 6, 5, 4, 3) transitions of Tb3+ ion, respectively. The excitation peaks of BaAl12O19:Dy are at 291, 324 nm and the emissions of Dy3+ are at 370, 447 and 578 nm, originating from 4F9/2 --> 6P5/2, 4F9/2 --> 6H15/2 and 4F9/2 --> 6H13/2 transitions of Dy3+ ion, respectively.

Near-infrared luminescence from Y2O3:Eu3+, Yb3+ prepared by sol-gel method.

Eu3+ and Yb3+ codoped Y2O3 phosphors were synthesized by the sol-gel method. The phosphors possess absorption in the region of 300-550 nm, exhibiting an intense NIR emission of Yb3+ around 1000 nm, which is suitable for matching the maximum spectral response of c-Si solar cells. The optimum composition of Eu3+ and Yb3+ codoped Y2O3 was (Y1.94Yb0.04Eu0.02)2O3. It is observed that two-step energy transfer occurs from the 5D2 level of Eu3+ situated around (466 nm) exciting two neighboring Yb3+ ions to the 2F5/2 level (1000 nm). The down-conversion material based on Eu(3+)- Yb3+ couple may have great potential applications in c-Si solar cells to enhance their photovoltaic conversion efficiency via spectral modification.