2.Evaluation of the fit of cobalt-chromium crowns fabricated by selective laser melting
Yuqi DANG ; Chunbao ZHANG ; Weina WANG ; Bo GAO
Journal of Practical Stomatology 2015;(3):313-317
Objective:To compare the adaption of cobalt-chromium prostheses fabricated by selective laser melting(SLM)and conven-tional lost wax technique(LW)method.Methods:Cobalt-chromium crowns and three-unit fixed dental prostheses(FDPs)were fabrica-ted by selective laser melting(SLM)or by conventional lost wax technique(LW)respectively(n =5).Marginal fit and internal fit were examined using a light-body silicone.After setting,each silicon film was cut into 2 parts and the thickness of silicon layer was measured at 1 00 ×magnification using a digital microscope,the data of marginal gap(MG)and internal gap(IG)were statistically analysed by ANOVA and SPSS statistical package version 1 7.0.Results:The MG and IG(μm)of cobalt-chromium alloy crowns in EOS M270 group were 42.28 ±1 1 .58 and 1 25.75 ±47.67,in EOS M280 group 46.54 ±8.4 and 1 28.22 ±54.1 8,in LW group 48.66 ±1 2.08 and 1 35.37 ±46.89.The MG and IG(μm)of three-unit FDPs in EOS M270 group were 40.55 ±1 0.04 and 1 33.09 ±39.80,in EOS M280 group 45.36 ±1 0 and 1 38.94 ±50.61 ,in LW group 54.24 ±1 2.04 and 1 51 .87 ±61 .94(P <0.05),respectively.Conclu-sion:The marginal fit of the SLMgroup is superior to that of the LW group and significantly smaller than 1 20 μm of clinical generally accepted standards.SLMsystem can satisfy the clinical requirements.
3.Clinical observation of the marginal and internal fit of titanium crowns fabricated by a selective laser mel-ting technology
Kenan CHEN ; Jinghong MAO ; Yuqi DANG ; Bo GAO
Journal of Practical Stomatology 2016;32(3):317-320
Objective:To compare the marginal and internal fit of selective laser melting(SLM)titanium crowns with lost-wax cast (LW)titanium crowns.Methods:Titanium crowns of 10 subjects were fabricated by SLM and conventional LW respectively(n =10).The marginal and internal gaps of the crowns were recorded with silicon film using a replica technique.Each silicon film was cut into 2 parts and the thickness of silicon layer was measured at ×100 magnification using a stereomicroscope,the data of marginal gap (MG)and internal gap(IG)were statistically analysed by ANOVA and SPSS statistical package version 17.0.Results:The MG (μm)of the titanium crowns of SLMgroup and LMgroup were 90.67 ±14.7 and 94.77 ±21.9(P <0.05),IG were 213.73 ±90.4 and 217.00 ±97.7(P >0.05),respectively.Conclusion:The marginal fit of the SLMcrowns is better than that of the LW ones,and is significantly smaller than 120 μm of the clinical generally accepted standards.
4.Purification and N-terminal Amino Acid Sequencing of the ESM Protease Isolated from an Eggshell Mem-brane-degrading Bacteria
Bo LI ; Yong DANG ; Yu MA ; Ying-Yi CHEN ;
Microbiology 2008;0(08):-
A strain producing eggshell membrane protease (ESM protease) was isolated from the soil and identified as Pseudomonas aeruginosa. The enzyme isolated from the fermentation liquid of this strain and purified by ammonium sulfate precipitation, quadratic anion-exchange chromatography exhibited eggshell membrane degrading activity of 304.5 U/mg. By SDS-PAGE, the protein molecular mass is 32 kD. The N-terminal amino acid sequence of this protease is: Ala, Glu, Ala, Gly, Gly, Val, Ala, Gly, Lys, Glu, Asp, Ala, Ala, Glu, Leu.
5.Study on variation of total flavonoids in Erigeron breviscapus
Dingxia FENG ; Bo CHEN ; Chenglin DANG ; Wenhua SU ; Chongyun WANG
Chinese Traditional and Herbal Drugs 1994;0(04):-
Object To study the variation of total flavonoids in Erigeron breviscapus (Vant.) Hand.-Mazz. with the development periods, the months, the affection of the environment and genetical factors on the total flavonoids. Methods The total flavonoids in organs of E. breviscapus during the different deve-lopment periods and the months were determined. The total flavonoids of E. breviscapus in the sunny and shady habitats and the total flavonoids of E. breviscapus with different colors were compared. Results The total flavonoids of E. breviscapus mainly existed in the ground part. The total flavonoids of E. breviscapus are the highest in its flourishing period, and the lowest in its withering period. The variety of the total flavonoids in every organs of E. breviscapus in flourishing period from April to June was not significant. Illumination intensity had little affection to the total flavonoids of E. breviscapus. The colors of E. breviscapus flowers could not be the selected markers for the total flavonoids. The genetic factor played an important role in deciding the difference of the total flavonoids among the individuals. Conclusion It will be optimistic to improve the total flavonoids in E. breviscapus by genetic breeding.
6.The value of three-dimensional ultrasound in evaluating carotid artery plaquevolume and predicting risk events in coronary heart disease patients
Yan SONG ; Ying DANG ; Jing SHANG ; Bo LIU ; Litao RUAN
Journal of Xi'an Jiaotong University(Medical Sciences) 2017;38(5):706-709
Objective To assess whether the plaque volume of carotid artery evaluated by three-dimensional ultrasound can predict the risk of cardiovascular events earlier in patients with coronary heart disease, in comparison with plaque thickness.Methods A total of 99 patients were enrolled, including 66 patients with asymptomatic carotid plaque and 33 patients with coronary heart disease (CHD) and carotid plaque.Three-dimensional ultrasound was performed in all the patients.Coronary angiography was performed in all the patients in CHD group.Coronary artery Gensini score was calculated.Plaque thickness, plaque area and plaque volume were compared between the two groups.We analyzed the relationship of plaque volume with Gensini score and other cardiovascular risk factors.Results Plaque volume was significantly higher in CHD group [(1312.38±513.70)mm3] than in asymptomatic group [(947.54±321.41)mm3] (P=0.023).However, plaque thickness and plaque area were not significantly different between the two groups (P>0.05).Plaque volume was positively correlated with Gensini score (r=0.519, P=0.002), homocysteine (r=0.569, P=0.002), and cardiovascular risk factors such as diabetes, blood glucose and glycosylated hemoglobin.There was a negative correlation between plaque volume and high-density lipoprotein (HDL), a factor protecting against cardiovascular events (r=-0.387, P=0.038).Conclusion Compared with plaque thickness, the volume of carotid plaques assessed by three-dimensional imaging technique may be a better predictor of the risk of cardiovascular events in patients with coronary heart disease.
7.Advances in gene chips for early gastric cancer
Shaohua DANG ; Hongliang JI ; Bo LI ; Xiangdong SUN ; Qingshan HANG
International Journal of Surgery 2011;38(12):845-847
Gastric cancer incidence is one of the most common malignancies in our country and is the second most common in the worldwide,clinic doctors always emphasize early diagnosis and treatment of gastric cancer patients,in order to reduce the mortality,however,most patients' condition often have been in the late fall and these patients were badly in efficacy.Looking for a new diagnosis way is a medical prddem,with molecular biology advance and gene chips was improved,it is possible for the early screening of gastric cancer.This assay aims to briefly analyse the role of gene chips in the research progress of early gastric cancer.
8.Simultaneous Determination of Acetaminophen and its Related Metabolites by LC-MS/MS
Bo GUO ; Xiuling TANG ; Lei SHI ; Xueliang DANG ; Yan ZHANG
China Pharmacist 2017;20(4):597-602,616
Objective:To establish an LC-MS/MS method for the simultaneous determination of acetaminophen and its five metabolites in mice plasma,and investigate the metabolism of acetaminophen by using the method.Methods:Para aminobenzoic acid was used as the internal standard.The plasma samples were precipitated by methanol,and then separated on a C18 column with the mobile phase of methanol and 5 mmol·L-1 ammonium acetate buffer solution containing 0.1% formic acid (55∶45).The flow rate was 0.5 ml·min-1,and the column temperature was 25℃.An electrospray ionization source was applied and operated in a positive ion mode using MRM:APAP,-,m/z 152.0→110.0;APAP-cys,-,m/z 271.2→140.1;APAP-glut,-,m/z 457.0→328.0;APAP-NAC,-,m/z 313.4 →208.0;APAP-sulf,-,m/z 232.4→152.1;APAP-gluc,-,m/z 328.2→152.1;IS,-,m/z 138.2→120.0.Results:The method exhibited good linearity over the concentration range of 0.2-10 μg·ml-1for APAP,1.0-20 μg·ml-1 for APAP-gluc,1.0-20 μg·ml-1 for APAP-sulf,1.0-20 μg·ml-1 for APAP-glut,0.4-15 μg·ml-1 for APAP-NAC and 0.2-10 μg·ml-1 for APAP-cys (r≥0.990 0).The inter-day accuracy and precision of acetaminophen and its five metabolites were all below 15%.The average recovery was between 85% and 115%,and RSDs were all below 15%.Conclusion:The LC-MS/MS method is proved to be quick,sensitive and accurate,and suitable for the determination of acetaminophen and its five metabolites in mice plasma.
9.Combined detection of pleural biopsy under medical thoracoscopy and serum tumor markers in diagnosis of pleural effusion with unknown reason
Ting GAO ; Xiaopeng HE ; Yan DANG ; Yujuan MA ; Bo ZHU
China Journal of Endoscopy 2016;22(12):20-25
Objective To discuss combined detection of pleural biopsy under medical thoracoscopy and pulmonary serum tumor markers in diagnosis of pleural effusion with unknown reason.Methods 76 patients with pleural effusion caused by unknown reason from January 2014 to March 2016 were retrospectively analyzed. Pleural biopsy was conducted under medical thoracoscopy and sent for pathological examination, and 10 ml venous blood was collected from these patients upon admission for testing serum tumor markers (CEA, SCC-AG, ProGRP and CYFRA21-1).Results Among the 76 patients, there were 32 cases with benign lesions (14 with pulmonary tuberculosis, 9 with inlfammatory lesions, 6 with granulomatous inlfammation, 2 with empyema and 1 with hamartoma) and 44 cases with malignant lesions (18 with adenocarcinoma, 13 with squamous carcinoma, 6 with small cell lung cancer, 3 with adeno-squamous carcinoma, 2 with mesothelioma, 1 with large cell carcinoma and 1 with thymoma). The detection of serum tumor markers showed statistically significant differences in the levels of CEA, SCC-AG, ProGRP and CYFRA21-1 in serum between the malignant pleural effusion group and benign pleural effusion group (P = 0.021,P = 0.006,P = 0.003 andP = 0.010). The levels of various serum tumor markers in the malignant pleural effusion group were obviously higher than those in the benign pleural effusion group. According to the pathological results, patients with pleural effusions not caused by lung cancer (2 with mesothelioma and 1 with thymoma) were eliminated from 44 patients with malignant pleural effusions. The rest 41 patients with pleural effusions caused by lung cancer were divided into non-small cell lung cancer and small cell lung cancer according to the pathological types. The results showed that there were statistically signiifcant differences in the levels of CEA, ProGRP and CYFRA21-1 between non-small cell lung cancer and small cell lung cancer (P = 0.036,P = 0.005 andP = 0.008), while there was no statistically signiifcant difference in the level of SCC-AG (P = 0.811).Conclusions Due to high detection rate and high accuracy in detecting pleural effusions caused by unknown reason, medical thoracoscopy is of great signiifcance, especially for the diagnosis of malignant pleural effusions of pleural metastases. However, serum indicators may provide important reference values for us before the pathological results are available. Thus, it is an important means of diagnosing malignant pleural effusions caused by lung cancer and should be promoted in clinic.