OBJECTIVEThis study aims to determine the effect of fluoride concentration on the corrosion behavior of cobalt-chromium alloy fabricated by two different technology processes in a simulated oral environment.

METHODSA total of 15 specimens were employed with selective laser melting (SLM) and another 15 for traditional casting (Cast) in cobalt-chromium alloy powders and blocks with the same material composition. The corrosion behavior of the specimens was studied by potentiodynamic polarization test under different oral environments with varying solubilities of fluorine (0, 0.05%, and 0.20% for each) in acid artificial saliva (pH = 5.0). The specimens were soaked in fluorine for 24 h, and the surface microstructure was observed under a field emission scanning electron microscope after immersing the specimens in the test solution at constant temperature.

RESULTSThe corrosion potential (Ecorr) value of the cobalt-chromium alloy cast decreased with increasing fluoride concentration in acidic artificial saliva. The Ecorr, Icorr, and Rp values of the cobalt-chromium alloy fabricated by two different technology processes changed significantly when the fluoride concentration was 0.20% (P < 0.05). The Ecorr, Icorr, and Rp values of the cobalt-chromium alloy fabricated by two different technology processes exhibited a statistically significant difference. The Icorr value of the cobalt-chromium alloy cast was higher than that in the SLM group cobalt-chromium alloy when the fluoride concentration was 0.20% (P < 0.05). The Ecorr, tRp alues of the cobalt-chromium alloy cast were lower htan those of the SLM group cobalt-chromium alloy when the fluoride concentration was 0.20% (P< 0 .05).

CONCLUSIONFluoride ions adversely affected the corrosion resistance of the cobalt-chromium alloy fabricated by two different technology processes. The corrosion resistance of the cobalt-chromium alloy cast was worse than that of the SLM group cobalt-chromium alloy when the fluoride concentration was 0.20%.

Chromium Alloys ; Corrosion ; Fluorides ; Lasers ; Phosphates ; Saliva, Artificial ; Sodium Fluoride

ve To investigate the effects of selenium and zinc on the absorption, excretion and accumu-lation of fluoride in rats. Methods The contents of fluoride in serum, excrement, urine and bone were determined in Wistar rats drinking distilled water containing 100 mg/L NaF and orally perfused jointly with 0.1 mg/(kg? d) Na2SeO3 and/or 14.8 mg/(kg?d) ZnSO4 one time per two days continuously for 90 days. Results Na2SeO3 and/or ZnSO4 could increase the concentration of fluoride in urine, decrease the concentration of fluoride in serum and the content of fluoride in bone of rats. Exposure to ZnSO4 and joint exposure to Na2SeO3 and ZnSO4 could increase the content of fluoride in excrement. Conclusion ZnSO4 could inhibit the absorption of fluoride in intestine, Na2SeO3 and /or ZnSO4 could promote the excretion of urine fluoride and restrain the accumulation of fluoride in bone of rats.

The application and expanding of nasal endoscopic surgery,an epoch-making transform of rhinology,have a very close associations with medical imaging,which includes anatomy photograph,conceptual diagram,radiological imaging,nasal endoscopic image display system,operation photographic recording and computer assisted instruction courseware,etc.It is important to collect the medical imaging through various means and set up medical imaging resources library for nasal endoscopic surgery teaching.

Using sustained release tablets of gardenia extract as model drug and DPPH radical scavenging capacity as antioxidant index, the feasibility of using pharmacodynamics index was explored to evaluate sustained release tablets. Applying the established quantifiable method of DPPH radical scavenging to the dissolved liquid of model drug, release profiles and biological effects profiles were drawn, and their correlation was discussed. A good correlation was observed by linear regression and f2 actor, suggesting that the indicator could be used to evaluate sustained release tabletsofextracts of gardenia in which iridoids were mainly involved.
Antioxidants ; metabolism ; pharmacology ; Biphenyl Compounds ; metabolism ; Delayed-Action Preparations ; metabolism ; pharmacokinetics ; Free Radicals ; metabolism ; Gardenia ; chemistry ; Kinetics ; Linear Models ; Oxidation-Reduction ; drug effects ; Picrates ; metabolism ; Plant Extracts ; metabolism ; pharmacokinetics ; Tablets

Peptide cyclization, a pivotal approach to modifying linear precursors of proteins and pepticles, has been used to enhance their biological activities and serum stabilities. Recently, sortase A (SrtA) from Staphyloccus aureus becomes a promising new technology for efficiently incorporating site specific modifications into proteins, conjugating the cell surface and cyclizing the linear peptides. In this study, we constructed two recombinant expression systems, one with chitin binding domain and the other with six-histidine tag and chitin binding domain on the N-terminal of SrtA, separately. The results of enzymatic kinetics indicate that the two recombinant tags do not impair the transpeptidase activity of SrtA compared with the standard reaction reported under the same reaction condition. The two synthesized peptides with N-ternimal three glycines and C-terminal penta-amino acid motif, LPETG, were cyclized using immobilized and recycled SrtA. The SrtA-based cyclization promises to represent a simple method for easy and efficient enzymatic synthesis of large cyclic peptides.
Aminoacyltransferases ; metabolism ; Bacterial Proteins ; metabolism ; Cyclization ; Cysteine Endopeptidases ; metabolism ; Enzymes, Immobilized ; metabolism ; Kinetics ; Peptides ; metabolism ; Peptides, Cyclic ; biosynthesis ; Staphylococcus aureus ; enzymology

Objective:To observe the effect of liver-soothing and mind-regulating acupuncture method on the resting-state electroencephalography (EEG) in rats with post-traumatic stress disorder (PTSD),and to provide evidence for the effect mechanism study and clinical application of acupuncture intervention for PTSD.Methods:Sixty Sprague-Dawley (SD) rats were randomly divided into a blank control group,a model group,a grasping group,a paroxetine group and an acupuncture group,with 12 rats in each group.Except for rats in the blank control group,rats in the other groups were subjected to preparing the PTSD models using 'incarceration plus electric shock' method.After interventions,changes in rat behavior of each group were observed;changes in resting-state EEG were collected and analyzed with multichannel EEG acquisition and analysis system,and image analysis and statistical processing were performed.Results:Compared with the blank control group,the average escape latency in the model group was significantly longer (P＜0.05),and the times of crossing the platform and the effective areas were all significantly reduced (P＜0.01).Compared with the grasping group,the average escape latencies in the paroxetine group and acupuncture group were significantly shortened (P＜0.05),and the times of crossing the platform and the effective areas were all significantly increased (P＜0.05).There were no significant differences in the average escape latency,the times of crossing the platform and the effective areas between the acupuncture group and paroxetine group (all P＞0.05).Compared with the blank control group,the α-wave power spectrum value in the model group was significantly decreased,and the power spectrum values of β-wave,δ-wave and a-wave were significantly increased (all P＜0.01);compared with the grasping group,α-wave power spectrum values in the paroxetine group and acupuncture group were significantly increased (both P＜0.01),and the power spectrum values of β-wave,δ-wave and a-wave were decreased significantly (all P＜0.01).The power spectrum values of α-wave,β-wave,δ-wave and (e)-wave of rats in the acupuncture group were not significantly different from those in the paroxetine group (all P＞0.05).Conclusion:Liver-soothing and mind-regulating acupuncture method can significantly improve the abnormal EEG activity in PTSD rats,which may be one mechanism of liver-soothing and mind-regulating acupuncture method in effectively affecting the brain function in PTSD rats.

Immunization with influenza vaccine is an effective prophylactic strategy in preventing seasonal flu. In the elderly, the standard influenza vaccines are not as effective as in non-elderly healthy adults, since the elderly people are particularly susceptible to influenza. With the acceleration of the global aging process, it is necessary to develop novel influenza vaccines which are more effective in the elderly. This review discusses immunosenescence and the substantial progress that has been made in the influenza vaccines for elderly people.

OBJECTIVE: To study the inhibitory effects of short hairpin RNA (pshLMP1) combined with DNAzyme or alone on latent membrane protein-1 (LMP1)expression in HNE1 cell lines. METHOD: The pshLMP1 and DNAzymes were co-transfected with pEGFP-N1-1158 (a expression vector encoding LMP1 and EGFP fusion protein) into HNE1 cells, divided into 4 groups as positive control, RNA interference, combining and DNAzyme groups. The green fluorescence were analyzed and then the mRNA and protein of LMP1 gene were detected. RESULT: The HNE1 cells expressing green fluorescence in combining group were significantly less than that in RNA interference group (P < 0.01); The inhibition efficiency of green fluorescence in combining group were 86. 31% Wp 88.88% ,which were higher than that in RNA interference group with 75.15%. The detection of LMP1 mRNA and proteins showed that combining group had a higher inhibition ability. CONCLUSION Combining gene therapy with pshLMP1 and DNAzyme is superior to pshLMP1 alone to inhibit LMP1 gene expression.
Cell Line, Tumor ; DNA, Catalytic ; therapeutic use ; Exons ; Gene Expression Regulation, Viral ; Genetic Therapy ; Humans ; Nasopharyngeal Neoplasms ; genetics ; metabolism ; pathology ; RNA, Small Interfering ; genetics ; therapeutic use ; Transfection ; Viral Matrix Proteins ; genetics

OBJECTIVETo study the production technology of extraction in combination hydrolysis in situ for isolating diosgenin from Dioscorea nipponica by orthogonal design.

METHODThe optimum production conditions were investigated with the recovery of diosgenin as an index by extraction in combination hydrolysis in situ, and were compared with the traditional method.

RESULTExtraction in combination hydrolysis in situ conducted in 1.5 mol x L(-1) sulfuric acid of water containing 75% isopropanol at 100 degrees C for 4.5 h could get higher recovery of diosgenin than traditional methods.

CONCLUSIONThis production technology can get higher recovery of diosgenin, and it is simple, time and money saving.

Dioscorea ; chemistry ; Diosgenin ; isolation & purification ; Hydrolysis ; Pressure ; Sulfuric Acids ; Technology, Pharmaceutical ; methods ; Temperature ; Time Factors

Three cyclotides were isolated from the whole plant of Viola yedoensis in this study. The two, vary peptide E and cycloviolacin Y5, were previously reported, and a novel cycloviolacin VY1 was characterized according to the interpretation of MS/MS fragmentation of peptides which were produced from the reduced and alkylated parent peptide with the digestion of Endo Lys-C, trypsin and chymotrypsin, separately. The stability of remarkable resistance to proteolytic degradation by trypsin and chymotrypsin, and that of thermal denaturation was confirmed again. Besides, the IC50 value of cycloviolacin VY1 against influenza A H1N1 virus was (2.27 +/- 0.20) microg x mL(-1). It is the first cyclotide reported with anti-influenza A H1N1 virus activity in vitro assay.
Antiviral Agents ; isolation & purification ; pharmacology ; Cyclotides ; pharmacology ; Influenza A Virus, H1N1 Subtype ; drug effects ; Tandem Mass Spectrometry ; Viola ; chemistry