[Endemic situation of schistosomiasis in a surveillance site of river and lake regions in Haining City, 2012-2014].

OBJECTIVE: To understand the endemic dynamics and situation of schistosomiasis in a provincial surveillance site in Haining City, Zhejiang Province. METHODS: The Oncomelania hupensis snail status, schistosome infection situations of permanent residents and floating population in Qinmin Village, Haining City were monitored from 2012 to 2014 according to The Surveillance Programs of Schistosomiasis in Surveillance Sites of Zhejiang Province. RESULTS: Totally 600 permanent residents were examined from 2012 to 2014. The total positive rate of the serum antibody against Schistosoma japonicum was 3.17% (19/600). The rates in each year were 2.50% (5/200), 0 (0/200), and 7.00% (14/200), respectively, and the rate in 2014 were significantly higher than that in 2013 (χ2 = 14.508, P < 0.01), but no positives were found in the fecal examination. Totally 1 591 floating population were involved in the surveillance, the positive rate of serum antibody were 0.94% (15/1 591). The rates in active surveillance and passive surveillance were 0.92% (14/1 521) and 1.43% (1/70), respectively, and there were no statistically significant difference between them (χ2 = 1.659, P > 0.05). The positive rates of serum antibody among each year were 1.50% (8/534), 0.56% (3/531), and 0.76% (4/526), respectively, and the difference was not statistically significant (χ2 = 2.752, P >0.05), but no positives were found in the fecal examination. The snail surveillance showed that there were no environments with infected snails and imported snails. CONCLUSIONS: There exist the infection sources of schistosomiasis in Haining City. Therefore, we should be on high alert for the potential of local endemic of the disease. Meanwhile, we still should strengthen the snail surveillance as well as the infection surveillance among the floating population.

Effects of three at-home bleaching agents on enamel structure and structure-related mechanical properties / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of three differently concentrated at-home bleaching agents on the structure and the structure-related mechanical properties of human enamel.</p><p><b>METHODS</b>Sixty enamel specimens were randomly divided into four groups and treated with 10% carbamide peroxide (CP), 15% CP, 20% CP and distilled water, respectively. The bleaching process was 8 h/day for 14 consecutive days. Baseline and final atomic force microscopy (AFM) surface detection, Raman spectroscopy, attenuated total reflectance-infrared spectroscopy (ATR-IR), microhardness and fracture toughness (FT) measurements were carried out before and after bleaching experiments.</p><p><b>RESULTS</b>CP didn't change the morphology of enamel. Meanwhile, the three bleached groups and the control group had no significant difference in root mean square detection (P = 0.774), ν(2)CO(3)(2-) : ν(1)ν(3)PO(4)(3-) (P = 0.263) and microhardness (P = 0.829). The percentage of relative Raman intensity in the three bleached groups and the control group were (105.74 ± 11.34)%, (104.46 ± 8.83)%, (99.52 ± 9.32)% and (97.62 ± 7.46)%, respectively. There was no significant difference among them (P = 0.062). However, the percentage of laser-induced fluorescence in the three bleached groups and the control group were (20.86 ± 7.23)%, (22.14 ± 7.34)%, (21.10 ± 7.59)% and (100.78 ± 3.70)%, respectively. There was significant difference between either of the bleached groups and the control group (P < 0.001). Moreover, FT declined significantly in the three groups (P = 0.024, P = 0.005, P = 0.013) when compared with the control group.</p><p><b>CONCLUSIONS</b>Under in vitro condition, three differently concentrated at-home bleaching agents wouldn't induce the demineralization and the decline of microhardness on enamel. However, the decrease of FT on enamel seemed to be inevitable after bleaching.</p>

The preparation of nano-hydroxyapatite and preliminary observation on its effects on the occlusion of dentinal tubule / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To synthesize nano-hydroxyapatite (nano-HA) and evaluate its effect on the occlusion of dentinal tubules in vitro, and therefore provide evidence for the clinical application.</p><p><b>METHODS</b>(NH(4))(2)HPO(4) and Ca(NO3)2 were used to form nano-HA, which was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectrometer (FTIR) and X-ray diffractometer (XRD) respectively. Twenty-four dentin slabs were obtained from 8 healthy third molars and randomly divided into 3 groups, which were control group, casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) group, and nano-HA group. After the CPP-ACP and nano-HA were topically applied to the slabs of two study groups twice a day for 7 days, the surface of slab dentin was observed using SEM.</p><p><b>RESULTS</b>SEM, TEM, FTIR, and XRD tests showed that nano-HA was synthesized successfully. SEM observations revealed that the sealing of dentinal tubules of nano-HA group was extremely high when compared with those of control and CPP-ACP group.</p><p><b>CONCLUSIONS</b>In comparison with CPP-ACP, nano-HA could occlude dentinal tubules more effectively in vitro.</p>