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Even though numerous bioinspired catalysts have been developed, there remain huge gaps between the artificial and natural catalysts, because it is very difficult to imitate simultaneously the complicated constituents, structures, and synergistic effect of enzymes. We report herein a versatile metalloporphyrinic framework platform, which exhibits high efficiency in bioinspired catalysis, photocatalysis, and asymmetric catalysis. The catalytic properties are highly dependent on the tunable constituents and their cooperation, and are significantly superior to the corresponding molecular catalyst systems which lack the synergistic effects. Since there are numerous functional moieties that can readily be incorporated into the metalloporphyrinic framework platform, a myriad of applications can be simply realized by embedding different functional moieties.
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Organic metalloporphyrins and inorganic polyoxometalates (POMs) are two kinds of efficient molecular catalysts to prompt a variety of chemical reactions. They have been used as active moieties for the synthesis of porous materials to realize highly efficient heterogeneous catalysis. Both of them are regarded as the organic/inorganic equivalent counterparts to complement the individual features. Therefore, the combination of metalloporphyrins and POMs in the same hybrid materials might generate interesting catalytic properties by emerging their unique individual functions. To avoid the random connections between metalloporphyrins, POMs, and lanthanide connecting nodes, we have developed a "step-by-step" aggregation strategy, including the reaction of POMs with metal ions to bind metal nodes on the surfaces of POMs at the first step and the reaction of the resulting POM derivatives with metalloporphyrin linkers to result in hybrid materials at the second step. Catalytic experiments demonstrate that the resulting hybrid material exhibits interesting catalytic properties in the heterogeneous epoxidation of olefins, in which the conversion, epoxide selectivity, turnover number, and turnover frequency for the epoxidation of styrene to (1,2-epoxyethyl)benzene are >99%, 94%, 220000, and 22000 h(-1), respectively. These results demonstrate that the collaborative work of multiple active sites in hybrid materials can achieve superior high efficiency in heterogeneous catalysis.
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OBJECTIVE: To develop a spatio-temporal model of schistosomiasis japonica based on Bayesian model, and to analyze the spatio-temporal pattern of schistosomiasis, as well as to evaluate the impact of environment changes on schistosomiasis endemic. METHODS: Different Bayesian models were established by employing the data of the periodical surveillance on schistosomiasis during 1996-2005 period by taking into account of the uncertainty in sensitivity and specificity of diagnostic test, then the best fitness model was selected to analyze the spatio-temporal pattern of schistosomiasis and evaluate the impact of environment changes on schistosomiasis. RESULTS: The model with space-time interaction was a better fitting model. No significant temporal correlation was found in human infection rate of Schistosoma japonicum, and the difference of spatial structure between human infection rates of each year was significant. The prediction map of S. japonicum infection showed the changes of infection in the south areas of the Yuan River were not significant, while the prevalence increased significantly in the north areas of the river, which indicated that the impact of the implementation of project on partial abandon areas for water storing on prevalence of S. japonicum was stronger than that of the project on completed abandon areas for water storing. CONCLUSIONS: It is feasible to develop the spatio-temporal model of schistosomiasis japonica based on Bayesian model, and this inetegrated Bayesian model approach may become a powerful and statistically robust tool for estimating and evaluating the control strategy.
Assuntos
Modelos Estatísticos , Esquistossomose Japônica/epidemiologia , Teorema de Bayes , China/epidemiologia , Humanos , Esquistossomose Japônica/diagnósticoRESUMO
OBJECTIVE: To study the indicators and validity of inquiry in the screening of chronic schistosomiasis japonica. METHODS: 51 villages of Hanshou county were selected at random in Hunan Province and the whole resident (>6 months/year) population aged 5 years and above was eligible for inclusion in the study. Inquiry through questionnairing, serological test (ELISA) and B type ultrasonography were applied respectively to screen chronic cases and evaluate morbidity due to schistosome infection. Logistic analysis was performed to explore the relationship between indicators of questionnaire and the results of ELISA and abdominal ultrasonography. Bayes discriminant analysis was used to assess consistency of inquiry and ELISA, inquiry and the degree of hepatic fibrosis. RESULTS: 26,426 inhabitants in the endemic villages were screened by ELISA with 1380 (5.2%) positive. 1264 sero-positive and 1446 sero-negative cases were asked questions relating to schistosomiasis and examined by abdominal ultrasonography. Inquiry indices such as self-reported diarrhea, stool with mucus and fatigue during the last two weeks, history of infested water contact and times of treatment were specific to chronic schistosomiasis. The coincident rate for validation was 75.9% between inquiry and ELISA, and 75.4% between inquiry and hepatic fibrosis degree. CONCLUSION: Validity of inquiry was satisfactory in screening chronic schistosomiasis in endemic areas.
