Objective:To study the sensitization of two newly developed titanium alloys, TLE and TLM.Methods:According to ISO 10993-10:1995 standard,maximization test was conducted in guinea pig.The skin sensitization reactions,including erythema and oedema, induced by TLE, TLM, normal saline and 2,4-dinitrochlorobenzene were observed and scored respectively at 24,48 and 72 h exposure of the infusion of the materials. The allergenic rates and mean response score were calculated.Results:The allergenic rates and score of skin reaction of TLE and TLM were 0/15 and 0,those of normal saline 0/15 and 0,those of 2,4-dinitrochlo-robenzene 15/15 and 5,respectively.Conclusion: TLE and TLM both are not of sensitization.

?Objective: To develop the electroplated diamond grinding discs and burrs used on CEREC II CAD/CAM system. Methods: Using electroplated technology, the diamond grain and nickel were deposited together on the surface of stainless steel discs and burrs and then a composite electroplated diamond layer was formed, which was the method that diamond coated grinding discs and burrs were made. The experimental grinding discs and burrs were used to mill porcelain blocks on CEREC II CAD/CAM system and were compared with CEREC discs and burrs. Results: There were no significant differences between the experimental samples and CEREC samples on milling property and durability. Conclusion: The electroplated technology is simple and feasible. The diamond coated grinding discs and burrs made with this method can be used on CEREC II CAD/CAM system, but the further investigation is also needed.

Objective To develop a new Multiplex Allele-Specific polymerase chain reaction(MAS-PCR) assay to detect the main point mutations in the katG and rpoB genes, which has been reported to account for the majority of clinical Mycobaterium tuberculosis resistant to isoniazid and rifampin. Methods Based on the sequences of katG and rpoB genes, specific primers were designed to carry out the MAS-PCR to detect the most common mutations in codon315 of katG and codons 531,526,516 of rpoB gene. Results The purified DNA preparation of 96 clinical Mycobacterium tuberculosis strains were used to optimize PCR. No mutation was detected in 19 isoniazid-sensitive strains. The 315Ser point mutation was detected in 79.2%(61/77)of isoniazid-resistant strains, the type of mutation includes the most common S315T and the less common S315N, which could’t be detected by PCR-RFLP(polymerase chain reaction-restriction fragment length polymorphism). However, S315G couldn’t be detected by MAS-PCR and that will make a false negative. The mutations in codons 531,526,516 were detected by the MAS-PCR. Compared with the results of direct sequencing of rpoB gene, no mutation was detected in sensitive strains. For rifampin-resistant strains, the total sensitivity was 81.5%(66/81). Conclusions MAS-PCR is a new molecular method with high sensitivity and specificity, which can be used to detect the point mutation in katG and rpoB gene rapidly and economically. It can be used in clinical laboratories to detect drug-resistant tuberculosis strains. Simultaneous detection for katG and rpoB gene mutations in one MAS-PCR system will help to improve the efficiency of this method.

In order to study the antibacterial activity of Chinese medicinal herbs to Ureaplasma ure- alyticum(Uu),we examined the inhibitory effect of 156 Chinese medicinal herbs to 14 standard strains of Uu by microdilution method in vitro.The results showed that Uu had a higher sensitivity to Cortex phellodendri,Radix angelicae dahuricae,Fructus kochiae,Radix et rhizoma rhei(MIC_(90)≤7.81mg of dried medicinal herbs/ml);a moderate sensitivity to Radix glycyrrrhizae,Radix isatidis,Rhizoma cop- tidis,Herba andrographitis,Herba houttuyniae(15.63≤MIC_(90)≤62.5);a lower sensitivity to Cortex meliae,Herba leonuri(62.5250).It is our opinion that Chinese medicinal herbs are of momentous signfi- cance in the treatment of Uu infection.

The debitterizing effect of ternary complexes was appraised and characterization of ternary complexes was made by infrared spectrum (IR) and differential scanning calorimetry (DSC). The ternary complexes (β-CD/BH/WPI90) of berberine hydrochloride (BH),β-cyclodextrin)β-CD (and whey protein isolate (WPI90) were prepared with adopting coprecipitation preparation. The results showed that the ternary complexesβ-CD/BH/WPI90 can sig-nificantly reduced the bitterness of BH. The content of BH in the ternary complexes was 3.20%. It was concluded that the ternary complexesβ-CD/BH/WPI90 had significant effect in reducing the bitterness of BH. IR and DSC of the ternary complexesβ-CD/BH/WPI90 were different from the simple physical mixture.

OBJECTIVE　To establish a CZE method for the simultaneous determination of magnolol and honokiol in cortex magnoliae officinalis and their supercritical fluid extract.METHOD　The buffer solution was 20 mmol*L-1 sodium borate(pH=10),the internal standard was sulfamethoxazole and the detection wavelength was 294 nm.RESULTS　Magnolol and honokiol in cortex magnoliae officinalis and their supercritical fluid extract were separated completely and determined accurately.The recoveries and the relative standard deviation were 99.40% and 1.6% for magnolol,and 98.44% and 1.4% for honokiol (n=3) respectively.CONCLUSION　The method was simple and accurate and it can be used for the quality control of magnolol and honokiol in cortex magnoliae officinalis and their supercritical fluid extract.

OBJECTIVE:To establish an HPLC method for the determination of lipoic acid in lipoic acid sustained-release tablets.METHODS:HPLC was conducted on a Hypersil ODS with acetonitrile-0.05 mol?mL-1 potassium dihydrogen phosphate(45∶55,adjust pH to 2.0)as mobile phase at a flow rate of 1.0 mL?min-1.The injection volume was 10 ?L;the detection wavelength was set at 219 nm and the column temperature was 25 ℃.RESULTS:The linear range of lipoic acid was 9.99～399.70 ?g?mL-1(r=0.999)with an average recovery rate of 99.17%(RSD=0.40%);the intra-day and inter-day RSD were all less than 2.6%.CONCLUSION:The method is simple and accurate,and suitable for the determination of the content of lipoic acid in lipoic acid sustained-release tablets.

To improve the extraction of solanesol from tobacco waste, we developed an enzymatic cell wall-breaking process with combined cellulase and ligninase. The effects of reaction time, temperature, pH and enzyme/substrate ratio were determined. The results show that the catalytic effect was better than either single enzyme when the ratio of cellulase to ligninase was 15:1 (U/U). Under the optimized conditions of 175 U/g (enzymes/substrate), tobacco to water 1:5 (W/W), temperature 40 degrees C and pH 6.0, the concentration of solanesol in the solution could reach 0.33 g/L after 8 h. And the average leaching rate reached 96.53% which was 1.68 times of the extraction methods of chemical reflux. It provides new way for the extraction of solanesol from tobacco waste, and worthwhile to be further explored.
Cell Wall ; metabolism ; Cellulase ; metabolism ; Oxygenases ; metabolism ; Plant Leaves ; chemistry ; Terpenes ; isolation & purification ; Tobacco ; chemistry

Objective; To study the chromatic distribution of the chromatic value of Vitapan 3D- Master shade guide in color space. Methods: The color space of.Vitapan 3D-Master shade guide was measured and analyzed with CIE-1976-L* a* b. system and MINOLTA chromatic instrument (CR-321 ) under D65 standard source. Results: 26 shades of Vitapan 3D-Master could be divided into 5 groups according to the 3-dimensional layers. Inside the 2nd, 3th and 4th group, 6 shades distributed as equidistant ring circling M2 shade because their hue and chroma were different. The hue of L1. 5 and L2. 5 deflected to yellow, R1.5 and R2. 5 to red,that of M1-3 was intervenient. Conclusion: Vitapan 3D-Master shade guide is equidistant in color space and can be used more effeciently than Vitapan classical. Its chromatic value distribution perfectly and evenly covered color region of nature tooth.

Objective:To explore an improved osteotomy of mandible ascending ramus for the surgical approach to large tumors in parapharyngeal space.Methods:According to the operation of parotid gland, masseter muscle was cut near the border of mandibular angle till subperiosteum dissection to mandibular notch, vertical osteotomy outside mandibular foramen to 1.0 cm under mandibular notch, vertical to posterior border of ascending ramus, tumor was exposed and removed, bone plate was repositioned and fixed with titanium. Results:Tumors were completely removed in this way in 3 patients without complications. Conclusion:This surgical approach is suitable for the surgical removal of parapharyngeal interstitial giantism tumor.