Objective To develop a method for the determination of cobalt in urine by graphite furnace atomic absorption spectrometry(GFAAS).Methods Usingthe matrixmodifier tofind the best condition byimprovingthe cineration temperature and reducing the interference of gas phase in atomization stage.Results The best cineration temperature and atomization temperature was 1 200 ℃and 2 450 ℃respectively,taking15% PdCl2,NH3H2PO4 and HNO3 as the matrix modifier.The background absorb value was less than 0.05.The linear range was 0～75 ?g/L,the correlation coefficient was over 0.999,the average recovery rate was 97.2%,the relative standard deviations were 3.5%～6.5%,the detection limit was 1.5 ?g/L.The result of 16 urine samples determined with the present method showed no significant difference compared with that by using polarography.Conclusion This method is sensitive,accurate,simple and is applicable tothe determination ofcobalt in urine.

Objective To establish a SPE-HPLC method for the determination of carbaryl and atrazine in water.Methods Carbaryl and atrazine in water were extracted with Oasis HLB and were eluted with CH3OH,CH3OH-H2O(55:45) was applied as mobile phase,the flow rate was 0.8 ml/min,detection wavelength was 220 nm,column was Symmetry Shield RP18(150 mm ? 3.9 mm,5 ?m),carbaryl and atrazine in water were determined by PDA detector.Results The linear range of the method was 0.05-10.0 mg/L(y=316 263x-350 9,r=0.999 9,for carbary;y=140 151x-258 6,r=0.999 9,for atrazine),The lowest detected concentration was 0.0002 mg/L for carbary and 0.000 5 mg/L for atrazine,respectively(S/N≥3).The recovery rates were 89.6%-97.0%,and the relative standard deviation was 4.0%-6.7%.Conclusion The method was sensitive,accurate and repeatable,which was applicable to the determination of carbaryl and atrazine in water.

BACKGROUND:Nano-hydroxyapatite/polyamide 66 is a new nanobionic composite material and has good biocompatibility and bone conduction, but after implantation, whether the composite material can bind to vertebral bone interface and whether it is safe in clinical use stil need further studies. OBJECTIVE: To observe the ability of nano-hydroxyapatite/polyamide composite binding to the interface of artificial humeral head. METHODS: The rabbits were randomly divided into two groups: composite group was implanted with nano-hydroxyapatite/polyamide composites; control group implanted with autologous bone. After the replacement, rabbit bone marrow mesenchymal stem cels were subjected to primary culture, and then the cels were co-cultured with the composite material. RESULTS AND CONCLUSION:At 24 hours after culture, bone marrow mesenchymal stem cels grew wel on the composite materials. The cel adhesion rate was significantly higher in the composite group than the control group at 1 and 4 hours after culture (P < 0.05). After co-culture 4.5, 5.5, 6.5 hours, the absorbance value of cels in the composite group was higher than that in the control group (P < 0.05). At 24 weeks after replacement, changing ranges in the proportions of bone tissue and fibrous layers on the implant surface as wel as coverage rate in the composite group were the highest (P < 0.05). These findings indicate that the nano-hydroxyapatite/ polyamide composite implant has a certain binding capacity, which can make a good interface osseointegration.

BACKGROUND: Three-dimensional (3D) printing technology is a new rapid prototyping and rapid manufacturing technology. OBJECTIVE: Through the analysis of the related papers, the paper summarizes and discusses the research progress of 3D printing technology, the prospect of application in joint replacement and the status quo and development trend of 3D printing technology in joint replacement.METHODS: The relevant literature was retrieved by the first author with the China Journal Full-text Database (CNKI) and PubMed database from 1985 to 2015. The key words were 3D printing technology, rapid prototyping, arthroplasty, joint replacement. The included 81 articles were analyzed.RESULTS AND CONCLUSION: Basic research and clinical application of 3D printing technology and joint replacementtechnology are becoming more and more popular. 3D printing further optimizes in the communication and teaching in joint replacement, and avoids intraoperative and postoperative complications. According to the needs of different teaching materials, 3D printing can print out different parts of the real body with different characteristics of print by 3D printer. The surgical simulation exercises with 3D limb printing different materials are the best way to improve theoperation skills. 3D printing technology in the osteotomy guide precision has basically completed multicenter clinical trial,and toward to the clinical application of small scale stage. The construction of individualized treatment plan and theapplication of active biological organs by 3D printing technology will become the new research direction of jointreplacement.

Adolescent ; Adult ; Amanita ; Chemical and Drug Induced Liver Injury ; etiology ; therapy ; Female ; Humans ; Male ; Middle Aged ; Mushroom Poisoning ; therapy ; Retrospective Studies ; Young Adult

Objective:To investigate hard-tissue changes in borderline cases with extraction and non-extraction during treatment and follow-up stages.Methods:Five associate professors,who were from Peking University School and Hospital of Stomatology,were asked to make judgment on the cases with full pre-treatment records for discriminating the borderline cases from extraction and non-extraction cases.Fifty-four borderline cases with full treatment records which had been out of treatment for at least 2 years were followed.Twenty-one cases with follow-up records were collected including 8 extraction cases and 13 non-extraction cases.Cephalometric measurements were preceeded in IDAS(Image and Database Analysis System) software program.Results:In extraction group,significant changes of SNB,SNPg in A-P direction and that of ArGo/ANSMe,MP/SN in vertical direction were present during the follow-up stage,while the overjet was stable.In non-extraction group,only decrease of proclination of lower incisor and increase of overjet were present without any skeletal changes during the follow-up stage.In comparison of the two groups,no skeletal and dental changes showed statistically significant difference except for MP/SN and ArGoGn in pre-treatment stage,while dental characteristics in relation to upper and lower incisor(L1/NB,L1-NB,L1-AP,U1-AP,U1/L1) showed statistically significant difference between the two groups after treatment.But in follow-up stage,the skeletal and dental pattern tended to be similar for both groups only except for the proclination of lower incisor.Conclusion:The similarities of skeletal and dental pattern are demonstrated in extraction and non-extraction group before treatment.Dental changes are the major post-treatment changes in the two groups.In follow-up stage,counter-clockwise rotation of mandible is unique in extraction group,which is likely a hepful factor for stability of overjet,while lingual tipping of lower incisor in non-extraction group without skeletal changes may contribute to overjet relapse.

In view of the contradictory phenomenon between yingfen dominating the interior when suffering exogenous epidemic febrile disease and ying disease dominating the exterior in cold pathogenic diseases,the authors revealed the misunderstanding of yingfen dominating the interior in epidemic febrile disease by a systematical analysis on the headstream of the theory,the connotation for diagnosis and treatment and logical relation. Based on the requirement of the theory guiding the clinical effectively,at the same time,the authors put forward a new opinion on classification of diagnosis and treatment on wei,qi,ying,blood system by the theory of the cold integrating the warm,which was a courageous exploration for the purpose of seeking unity of thinking on syndrome differentiation and treatment of external infection diseases.

In view of the contradictory phenomenon between yingfen dominating the interior when suffering exogenous epidemic febrile disease and ying disease dominating the exterior in cold pathogenic diseases,attemping to get the logical demonstration that cold pathogenic diseases and exogenous epidemic febrile diseases can be integrated by yingfen diseases,the authors made a systematic classification and comparison on basis of the collection of related diagnosis and treatment in respective yingfen diseases of cold pathogenic diseases and exogenous epidemic febrile disease. It was of vital importance to connecting cold pathogenic diseases with exogenous epidemic febrile diseases in classification of diagnosis and treatment in wei,qi,ying,blood system.

Objective To establish a high performance liquid chromatographic method for determination of 6-methyl coumarin in cosmetics. Methods Samples were extracted with ethanol, On C18 column CH3CN-0.02 mol/L NaH2PO4(pH=3.5, 35∶65) was applied as mobile phase, 6-Methyl Coumarin in cosmetics was determined by photo-diode-array(PDA) detector. Results The linear range of the method was 1.0-25.0 mg/L. The lowest detected limit of 6-Methyl Coumarin in 1.0 g samples was 0.000 1%. The recovery rates were 96.6%-99.2%, and the relative standard deviation were 2.0%-4.4%. Conclusion The method was simple, rapid and accurate, which was suitable for determination of 6-methyl coumarin.