Carboxylate-functionalized sugarcane bagasse as an effective and renewable adsorbent to remove methylene blue.

This study prepared a carboxylate-functionalized sugarcane bagasse (CF-SCB) from sugarcane bagasse (SCB) via a simple and low-toxicity chemical modification to enhance its capacity for adsorbing methylene blue (MB) from aqueous solutions. The success of chemical modification was confirmed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), the pore area and porosity, and zeta potential measurement analysis. The adsorption capacity of CF-SCB was investigated at different pHs, ionic strengths, temperatures, contact times and initial dye concentrations. Equilibrium data were best described by the Langmuir isotherm model, and the maximum monolayer adsorption capacity of CF-SCB (296.74 mg g-1) was greatly improved compared with SCB (77.16 mg g-1) at 30 °C. The thermodynamic study indicated that MB adsorption onto CF-SCB was a spontaneous, endothermic and entropy increased process. Adsorption kinetics followed a pseudo-second-order mode, and the adsorption mechanism was based on electrostatic interactions. The reusability study showed that CF-SCB had reasonably good reuse potential. All the results suggested that CF-SCB has high potential to be used as an effective and renewable adsorbent for MB removal from wastewater.

[The effect of periodontal initial therapy on chronic periodontitis and subgingival periodontal pathogen].

PURPOSE: To evaluate the effect of periodontal initial therapy on clinical parameters and subgingival periodontal pathogen in patients with chronic periodontitis. METHODS: One hundred and twenty patients with chronic periodontitis were included. Probing depth (PD), attachment loss (AL), plaque index (PLI) and gingival index (GI) were evaluated at baseline and after-initial therapy. P.g and A.a in subgingival plaque were investigated by real-time PCR. Data was statistically analyzed by SAS6.12 software for Student's t test. RESULTS: The PD, AL, PLI and GI were significantly decreased after periodontal initial therapy (P<0.01), and meanwhile the ratio of P.g versus total bacteria was significantly decreased after-initial therapy (P<0.05). However, the change of ratio of A.a versus total bacteria was not significant (P>0.05). CONCLUSION: Periodontal initial therapy could effectively control the inflammation of chronic periodontitis, and decrease the ratio of P.g in subgingival plaque.

[A study on the state of periodontal health of 400 professional adults by random sampling in Shanghai].

PURPOSE: To investigate and analyze the state of periodontal health of 400 adults at their post and risk factors in Shanghai. METHODS: 400 subjects (249 male, 151 female), aged from 25 to 59, were requested to fill a questionnaire. The probing depth (PD), clinical attachment level (CAL), tooth mobility (TM) and bleeding on probing(BOP) on 6 sites of each indicated tooth were measured and recorded. SAS 6.12 software package was used for statistical analysis. RESULTS: OHI-S of Shanghai adults at their post was 2.16 +/- 0.99 and GI = 1.2227, indicating moderate gingivitis. The difference of periodontal disease among the adults at varied occupations in Shanghai municipality was significant. Periodontal destruction of the clerk group was the lightest The difference of periodontal disease among the adults at varied age groups in Shanghai municipality was also significant. Periodontal destruction of the elder group was heavier than of the lower age group. 146 subjects suffered from initial to moderate periodontitis. 140 subjects suffered from advanced periodontitis. 79, 317 and 4 subjects had received college education, high school education and postgraduate school education respectively. There was no relationship between the severity of periodontitis and educational level. 330 out of 400 (82.5%) subjects had never been treated, 70 out of 400 (12.5%) had scaling,and only 3.25% of subjects had received regular periodontal treatment. CONCLUSION: It is very important to develop an education program on oral health for people in Shanghai. Supported by National "Tenth Five-Year" Key Project (Grant No.2004BA720A26), Research Fund of the Science and Technology Committee of Shanghai Municipality (Grant No.0352nm126) and Shanghai Leading Academic Discipline Project(Grant No.94-III-008).

[The relationship between the calcaneus density and the degree of inflammation in patients with generalized aggressive periodontitis].

PURPOSE: To evaluate the relationship between the calcaneus density and the degree of inflammation in patients with generalized aggressive periodontitis. METHODS: Thirty one volunteers with healthy periodontium (as control group) and 38 patients with generalized aggressive periodontitis (as experimental group) were involved in this study. The average ages of the two groups were 27 and 23 years respectively. The clinical periodontal indexes and panoramic films were measured first. And the broadband ultrasonic attenuation(BUA) and T-score of the calcaneus were then determined using ultrasonic bone densitometer. SAS6.12 software package was used to analyse the data obtained. RESULTS: The BUA values of the two groups were 62.76+/-4.61 and 70.47+/-4.41 respectively, the BUA value of the experimental group was significantly lower than that of the control group (P<0.001). Moreover, T-score was different between the two groups and the score in the experimental group was significantly lower than that in the control (P<0.001). CONCLUSIONS: The BUA and T-score in patients with generalized aggressive periodontitis were significantly lower than that in the controls with healthy periodontium, which indicated that patients with generalized aggressive periodontitis had overall bone density decrease.