Biomedical Research ; trends ; Dental Implants ; Esthetics, Dental ; Humans ; Immediate Dental Implant Loading

Objective To observe the influence of sodium citrate concentrations in TISAB on detection of water fluoride,and to explore the feasibility of 0.10 mol/L sodium citrate buffer system in detection of water fluoride.Methods Under pH 5.0 to 5.5,a series of fluoride standards of 0.2,0.5,1.0,2.0 and 5.0 mg/L were measured when sodium citrate concentration was 0.01,0.10,and 1.00 mol/L in the TISAB system.The results of water fluoride measurement were compared,recovery calculated and regression equation of the standard curve was set up.The feasibility of 0.10 mol/L sodium citrate in the TISAB system to detect water fluoride was tested,including interference test,accuracy,confidence limits,as well as precision test.Water fluoride was determined by fluoride ion selective electrode according to the Standard Test Methods for Drinking Water (GB/T 5750.5-2006).Results When the sodium citrate concentrations in the TISAB system were 0.01,0.10 and 1.00 mol/L,and the concentrations of fluoride in the sample were 0.2,0.5,1.0,2.0 and 5.0 mg/L,recoveries of water fluoride were 96.0％,103.0％,179.5％; 80.6％,97.8％,132.2％; 73.3％,97.0％,103.0％; 70.0％,100.0％,87.5％; and 66.4％,102.0％,65.4％.The equation of linear regression was y =lg-1(226.4-E/47.4),y =lg-1(226.4-E/53.4) and y =lg-1(208.1-E/36.9) ; the correlation coefficient(r) were 0.9993,0.9999 and 0.9993.The minimum detectable concentration and limit of quantitation was 0.023 and 0.072 mg/L when sodium citrate was 0.10 mol/L in the TISAB system.Aluminum(Al3+,100 μg),ferrum(Fe3+,800 μg),calcium(Ca2+,1200 μg),Al3+(50 μg) + Fe3+ (800 μg),Al3+(50 μg) + Ca2+(1200 μg) can be masked when sodium citrate was 0.10 mol/L in the TISAB system.The total average recoveries confidence limit R/d was 0.99.The total standard deviation of standard solution,water sample and spiked water sample was less than 5％ of their respective mean concentration.Conclusions High concentration of sodium citrate buffer system has a significant influence on the detection sensitivity and limit of quantification of fluoride ion in water.The capacity of anti-interference of 0.10 mol/L sodium citrate in the TISAB is strong.The confidence limits of precision and accuracy meet the requirements for fluoride determination in a variety of source water and drinking water.

Objective To analyze the correlations between pediatric intersive cave unit (PICU) nurses′job satisfaction and their perception of job characteristics. Method One hundred and thirty-six PICU nurses from a women and children′s hospital of Guangzhou participated in the study and the job diagnostic survey (JDS) and Minnesota satisfaction questionnaire short-form (MSQ20) were used to investigate the relationship between the job characteristics and job satisfaction. Results The average score on general satisfaction was (3.57 ± 0.41). The dimensions like skill variety, task integrity, feedback from job and feedback from others, had a significant positive impact on general satisfaction (all P<0.05). Conclusion Nurses generally have a relatively middle level of job satisfaction and measures should be taken to improve their job satisfaction as well as the quality of nursing.

Vitamin C precusor-2-keto-L-gulonic acid can be prepared directly by mixed culture of Ghiconobacter oxy-dans SCB329 and Guconobacter subaxydans SCB110. To obtained its high yield, firstly, the proportion of the two micro- organisms, the ingredients of medium and the initial pH were optimized in shake flaskd, then L9 (34) orthogonal experiment confirmed that urea, C. S. L had high degree statistical meaning. Based on these data, an optimized fermentation media was obta ined: D-Sorbitol 9g, C. S.L1.5g, Urea1.5g, KH2PO40.1g, CaCO30.2g. By-product can be inhabited to the greatest extent and the yield increases by 20%.

Several kinds of column chromatography method were used to investigate the chemical constituents of the leaves of Lophatherum gracile. The structures of the isolated compounds were identified based on their physicochemical properties and spectral data. A new flavone C-glycoside was isolated and its structure was identified as 3'-methoxyl-luteolin 6-C-beta-D-galactopyranosiduronic acid (1 --> 2) -alpha-L-arabinopyranoside (1).
Antiviral Agents ; chemistry ; isolation & purification ; Flavones ; chemistry ; Glycosides ; chemistry ; isolation & purification ; Hydrolysis ; Plant Leaves ; chemistry ; Poaceae ; chemistry

OBJECTIVETo study the in-vitro inducing apoptosis mechanism of human hepatoma SMMC-7721 cells by 2',4'-di- hydroxy-6'-methoxy-3',5'-dimethylchalcone (DMC), a chalcone compound from Cleistocalyx operculatus.

METHODQuantitative DNA fragmentation assay was carried out to detect the effect of DMC of different concentrations on SMMC-7721 cells, according to the method of Sellins and Cohen with some modifications. Telomerase activities of the cells were determined by PCR-ELISA methods. The expression quantity of c-myc and hTERT mRNA were determined by semi-quantitative RT-PCR The effect of DMC on expression levels of cmyc and hTERT protein were measured by western blot.

RESULTThe percentage of DNA fragmentation increased with notable concen- tration dependence, after treatment with DMC for 48 h. Compared with that of control group, the telomerase activity of the cells de- creased by (66.2 ± 2.1)% after 48 h treatment with 20 μmol x L(-1) DMC, the mRNA expression of c-myc and hTERT decreased by (67.3 ± 2.1)% and (64.4 ± 2.3)%, respectively, and the protein expression of c-myc and hTERT decreased by (69.6 ± 1.9)% and (71.3 ± 2.4)%, respectively.

CONCLUSIONDMC can induce SMMC-7721 cell apoptosis and the apoptosis mechanism may be related to the decreased mRNA and protein expression of c-myc and hTERT.

Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; pathology ; Cell Line, Tumor ; Chalcones ; pharmacology ; DNA Fragmentation ; drug effects ; Dose-Response Relationship, Drug ; Humans ; Liver Neoplasms ; pathology ; Proto-Oncogene Proteins c-myc ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Syzygium ; chemistry ; Telomerase ; genetics ; metabolism

Atractylodis Macrocephalae Rhizoma and Atractylodis Rhizoma were widely used in strengthening spleen under different disease conditions, and were easily and often misused each other. Therefore, DNA barcode was used to distinguish Atractylodis Macrocephalae Rhizoma and Atractylodis Rhizoma from their adulterants to ensure the safe use. The sequence lengths of ITS2 of Atractylodes macrocephala, Atractylodis Rhizoma (A. lancea, A. japonica and A. coreana) were both 229 bp. Among the ITS2 sequences of A. macrocephala, only one G/C transversion was detected at site 98, and the average GC content was 69.42%. No variable site was detected in the ITS2 sequences of A. lancea. The maximum K2P intraspecific genetic distances of both A. japonica and A. coreana were 0.013. The maximum K2P intraspecific genetic distances of A. macrocephala, A. lancea, A. japonica and A. coreana were less than the minimum interspecific genetic distance of adulterants. The ITS2 sequences in each of these polytypic species were separated into pairs of divergent clusters in the NJ tree. DNA barcoding could be used as a fast and accurate identification method to distinguish Atractylodis Macrocephalae Rhizoma, Atractylodis Rhizoma, from their adulterants to ensure its safe use.
Atractylodes ; classification ; genetics ; DNA Barcoding, Taxonomic ; methods ; DNA, Plant ; genetics ; DNA, Ribosomal Spacer ; genetics ; Drug Contamination ; prevention & control ; Drugs, Chinese Herbal ; chemistry ; classification ; Molecular Sequence Data ; Phylogeny ; Quality Control ; Rhizome ; classification ; genetics

Actins ; metabolism ; Animals ; Male ; Morphine ; adverse effects ; Morphine Dependence ; metabolism ; Prefrontal Cortex ; metabolism ; Proteome ; metabolism ; Rats ; Rats, Sprague-Dawley ; Substance Withdrawal Syndrome ; metabolism ; Synaptosomal-Associated Protein 25 ; metabolism

Objective To study the structure of class 1 integrons in 90 strains of Pseudomonas aeruginosa isolated during two periods of 1992-1996 and 2003-2005,and to get information about the structure changing of class 1 integrons by comparing their structures in two different periods.Methods Routine PCR and long PCR were performed to amplify the class 1 integrons and the gene cassettes they carried, followed with sequencing and blast via GenBank.Results Thirteen out of 41 strians ioslated during the period of 1992-1996 were positive on class 1 intergrons.Long PCR showed that the class 1 integron was 1868 bp in length and contained 2 resistance genes averagely.Six types of resistance genes of qacEA1 (n=6), sull (n=14),aadA1 (n=2),aadB (n=1),PSE-1 (n=2) and tetA (n=1) were found in these integrons, which consisted of 5 patterns of resistance cassette arrangements.Nineteen strains were proved to carry class 1 integrons in 49 isolates from 2003-2005.The mean DNA sequence length of them was 3383 bp with 3.6 resistant genes in averagely,10 types of resistance genes,qacEA1 (n=18),sull (n=25),aadA1 (n=6), aadB (n=7),aacA4 (n=2),PSE-1 (n=3),VEB-1 (n=4),OXA10 (n=1),cm1 A (n=1) and tetA (n =2),were identified in these integrons,which were composed of 9 patterns of resistance cassette arrangements.Conclusion In terms of produce length and resistance cassettes carried in the integrons, greater complexity is found in the structure of class 1 integrons in strains isolated during 2003-2005 than those during 1992-1996.

Objective To study the relationship among apoptosis,NF-KB activation and uPA expres- sion in human colon carcinoma cell line HCTll6 induced by 5-fluorouracil,and to observe the effect of in- hibiting activity of NF-KB by PDTC on apoptosis as well as expression of uPA.Methods Cell apoptosis was analysed by Annexin V-FITC.Fluctuation of NF-KB and uPA was detected by semi-quantitative immuno- histochemistry.Results 5-fluorouracil could induce apoptosis and activate NF-KB.PDTC could significantly increase the apoptosis and suppress the activation of NF-KB induced by 5-fluorouracil.There was a positive correlation between the changes of uPA and NF-KB.Conclusion 5-fluorouracil could induce apoptosis,ac- tivate NF-KB and up-regulate expression of uPA of HCT116 cells.The mechanism of enhanced apoptosis by PDTC may be related to suppressing activation of NF-?B and down-regulating expression of uPA.