Objective: To study the corrosion resistance of orthodontic magnet with titanium nitride coating in artificial saliva. Methods: 6 samples of magnet in the size 3 mm?5 mm?7 mm were prepared.3 of them were coated with titanium nitride by plasma enhanced chemical vapor deposition,another 3 without coating were used as controls.The samples were immersed into artificial saliva at 37 ℃ for one month. Then the surface characters of two kinds of magnets were observed with the naked eye and by electron-probe microanalysis (EPMA). Results: The surface of the magnets with titanium nitride coating was fine and close in texture and there were no cleft and disintegrated area. However, that of the magnets without titanium nitride coating was uneven and coarse in texture,and there were evident clefts and disintegrated areas. Conclusion: The corrosion resistance of orthodontic magnets with titanium nitride coating is stronger than that without coating.

Objective: To study the corrosion resistance of the ortho do ntic magnets with titanium nitride (TiN) coating. Methods: The m agnets coated TiN film were immersed into artificial saliva at 37 ℃ for two mon ths. During the immersion, the concentration of iron ion in the artificial saliv a was analyzed with atomic absorption spectrophotometry(AAS). After immersion, t he weight change of the magnets was measured.The magnets coated with nickel film and without coating were used as the controls.Results: In all t he groups, iron ion concentration in the artificial saliva increased with the in crease of immersion time(P

OBJECTIVE:To provide reference for perioperative rational prophylactic application of antibacterials in type Ⅰ in-cision operation. METHODS:4 201 patients underwent type Ⅰ incision operation were collected from a class A grade three hospi-tal during Mar. 2013-Feb. 2015. The perioperative prophylactic application of antibacterials in type Ⅰ incision operation were ana-lyzed statistically. RESULTS:Of 4 201 patients underwent type Ⅰ incision operation,there were 2 399 cases of prophylactic appli-cation of antibiotics(accounting for 57.10%). Cephalosporins andβ-lactam/β-lactamase inhibitor were the main classes of antibacte-rials for preventive use,accounting for 45.60%and 19.76%,respectively. The frequency of using cefazolin,ceftriaxone and amoxi-cillin-clavulanic acid ranked the top 3 places, among which there was 823 cases of unsuitable prophylactic medication time (34.31%),and 855 cases of prophylactic medication time >48 h(accounting for 35.64%). CONCLUSIONS:There still is unrea-sonable perioperative prophylactic application of antibacterials in type Ⅰ incision operation in this hospital. It is necessary to strengthen the supervision of antibacterials and conduct regular rational antibacterials use seminars in order to promote rational use of antibacterials.

Voriconazole is a broad spectrum triazole antifungal agent, widely used in the prevention and treatment of invasive fungal diseases.Long-term use of voriconazole can induce periostitis and cutaneous squamous cell carcinoma, accounting for serious adverse effects on patients, which has been reported in increasing clinical cases.This review is to characterize the epidemiological and clinical manifestations of periostitis and squamous cell carcinoma induced by voriconazole, and to analyze the mechanisms of triggering periostitis and squamous cell carcinoma, so as to promote the rational use of voriconazole in clinics.

OBJECTIVE:To observe clinical efficacy and safety of salmeterol fluticasone combined with tiotropium bromide in the treatment of COPD via different inhalation devices.METHODS:Eighty COPD patients were selected from our hospital during Jan.2014 to Jan.2015,and then divided into trial group and control group according to random number table,with 40 cases in each group.Both groups were given Salmeterol fluticasone inhalant 500 μg,bid+Tiotropium bromide inhalant 18 μg,qd.Control group was given medicine via inhalation device coming with medicine,while trial group was given medicine via gas compression type ultrasonic spray inhalator.Both groups were treated for 1 year.Blood concentration of medicine 0.5 h after medication,mMRC score and COPD acsessment test (CAT) score 3,6,9 months after treatment,the times of acute exacerbation during treatment,FEV1％ before and af ter treatment were all observed in 2 groups.The occurrence of ADR was recorded.RESULTS:Four cases withdrew from trial group and 1 case from control group.After medication,there was no statistical significance in blood concentration of fluticasone,salmeterol and tiotropium bromide between 2 groups (P＞0.05).0.5 h after medication,mMRC score of trial group was slightly lower than that of control group,without statistical significance (P＞0.05);CAT score of it was significantly lower than that of control group,with statistical significance (P＜0.05).The times of acute exacerbation in trial group during treatment was significantly less than control group,with statistical significance (P＜0.05).The decrease of FEV1％ in trial group was slightly lower than control group,without statistical significance (P＞0.05).The incidence of ADR in trial group was significantly lower than control group,with statistical significance (P＜0.05).CONCLUSIONS:For COPD patients,salmeterol fluticasone combined with tiotropium bromide via gas compression type ultrasonic spray inhalator is better than inhalation device coming with medicine in clinical efficacy and safety.

Objective To establish an animal model for immunological contact urticaria in mice.Methods A total of 60 BALB/c mice were randomly and equally divided into 5 groups:anti-dinitrophenol IgE monoclonal antibody (anti-DNP IgE) + 2,4-dinitrofluorobenzene (DNFB) group and anti-DNP IgE + trimellitic anhydride (TMA) group both injected with anti-DNP IgE via tail veins firstly,followed by topical treatment with DNFB and TMA respectively on the ears at 24 hours after the injection,DNFB group,TMA group and normal saline (NS) group all injected with NS via the tail vein firstly,followed by topical treatment with DNFB,TMA and NS on the ears 24 hours after the injection.In the following 14 days,mice were observed daily for the appearance of wheals and for scratching behavior.All the mice were sacrificed at the end of the study followed by determination of the percentage of degranulated mast cells and spleen index as well as observation of pathological changes.Results Wheals were observed in all the mice (12/12) in the anti-DNP IgE + DNFB group,some mice (8/12) in the anti-DNP IgE + TMA group,but not observed in any mice in the other 3 groups.Compared with the NS group,both the anti-DNP IgE + DNFB group and anti-DNP IgE + TMA group showed a significant increase in the percentage of degranulated mast cells (70.21％ ± 26.01％ and 54.25％ ± 39.57％ vs.14.45％ ±6.79％,F=14.41,P=0.000),spleen index (7.54 ± 1.56 and 7.87 ± 1.18 vs.5.37 ± 1.16,F=4.29,P=0.004) and scratching frequency ((31.58 ± 3.58)/h and (22.17 ± 3.81)/h vs.(2.00 ± 0.85)/h at 30 minutes,F =437.86,P ＜ 0.01).Conclusion A stable mouse model for immunological contact urticaria can be established quickly by sensitization with anti-DNP IgE and challenge with DNFB.

Objective To determine the coagulation status as well as circulating levels of complement and inflammation markers in patients with chronic urticaria (CU) during acute attack and in remission,and to estimate the relationship of coagulant and anticoagulant factors as well as fibrinolytic markers with the development of chronic urticaira.Methods This study included 40 patients with CU (22 during acute attack and 18 in remission) and 40 healthy blood donors from the Guangzhou Blood Center.Venous blood samples were obtained from these subjects,and enzyme-linked immunosorbent assay (ELISA) was performed to measure the plasma levels of prothrombin fragrnent 1 +2 (F1 +2),tissue factor (TF),thrombomodulin (TM),high molecular weight kininogen (HMWK),tissue-type plasminogen activator (t-PA),C5a and serum levels of C3,C4,antistreptolysin O antibodies (ASO),rheumatoid factor (RF) and C-reactive protein (CRP).Erythrocyte sedimentation rate (ESR) was also determined in these patients.Comparisons of these parameters were carried out by using t test,and the correlation of these factors with CU was evaluated by using Spearman correlation coefficient.Results Compared with the healthy controls,the patients with CU showed significantly higher plasma levels of F1+2 and HMWK (both P ＜ 0.01),but lower levels of TF,TM and t-PA (all P ＜ 0.01).The plasma levels of F1 +2,HMWK,t-PA were significantly correlated with the symptom scores in patients with CU (r =0.81,P ＜ 0.01; r =-0.39,P ＜ 0.05; r =0.35,P ＜ 0.05).A significant increase was observed in the plasma concentration of F1 +2 in patients during acute attack compared with those in remission (P ＜ 0.01),whereas no significant differences were noted in the plasma levels of TF,TM,HMWK,t-PA,C5a,serum levels of C3,C4,ASO,RF and CRP or ESR between the two groups of patients (all P ＞ 0.05).Conclusions It seems that coagulation,anti-coagulation and fibrinolysis are all involved in the development of urticaria.There is an obvious difference in the plasma level of prothrombin F1 +2 between patients with CU during acute attack and in remission,suggesting that coagulation factors play a certain role in the initiation and progression of CU.

Objective To investigate the role of regulatory T (Treg) / T helper type 17 (Th17) cells in the pathogenesis of chronic spontaneous urticaria (CSU).Methods Eighty-nine patients with CSU were enrolled in this study,including 48 in active stage and 41 in remission stage.Forty-eight health check-up examinees,who were collected from the community hospitals in Guangzhou city,served as the healthy controls.Fluorescence-based realtime quantitative PCR was performed to determine the expression of transcription factors FOXP3 and RORγt in PBMCs from these subjects.Results Compared with the patients with CSU in remission stage and healthy controls,the patients in active stage showed a significantly higher level of FOXP3 mRNA (0.57 ± 0.19 vs.0.11 ± 0.21 and 0.13 ± 0.23,both P ＜ 0.05),but a significantly lower level of RORγt mRNA (0.43 ± 0.39 vs.0.89 ± 0.40 and 0.87 ± 0.43,both P ＜ 0.05).Conclusions The expression of Treg cell regulator FOXP3 increases,while the expression of Th17 cell regulator RORγt decreases in patients with CSU,suggesting that the imbalance between Treg and Th17 cells induced by the interaction between FOXP3 and RORγt may be involved in the pathogenesis of CSU.

Objective To explore the clinical head nurses'effective competence through interviewing nursing supervisors by in depth interview method and to provide reference for constructing training content for clinical head nurses in Macau and Guangzhou.Methods In depth interview was carried out among 8 nursing supervisors from 2 hospitals in Macau and 9 nursing supervisors from 2 tertiary hospitals in Guangzhou.Content analysis was utilized through organizing records and then forming written documentations.Results The themes were drawn after the interview,which were good moral character accomplishment,good communication skill,prospective and creative thinking,favorable executive ability.Forwardlooking and innovative were significantly different in Macau and Guangzhou.Conclusions The effective clinical head nurses' competence is multi-faceted,the results can provide reference for selection,evaluation and training for head nurses.

Objective To study the influence of sunscreens with different efficacy on delayed type hypersensitivity (DTH) and their immunoprotective effect in mice.Methods A cohort of mice were randomly divided into 5 groups with 10 mice in each group:group 1 as the positive control without irradiation,group 2 receiving solar-simulated radiation (SSR) only,group 3 receiving SSR and protected by sunscreen l with sun protection factor 15(SPF15)and persistent pigment darkening(PPD)12,group 4 receiving SSR and protected by sunscreen 2 with SPF 50 and PPD 28,and group 5 as the negative contml receiving SSR only.SSR was carried out on the back of mice with the UVA dose being 1.4 J/cm2 and UVB dose being 100 mJ/cm2 for 10 days.After a 5-day irradiation,the groups 1 to 4 were immunized by intraperitoneal injection with 100 μl(107 cells/ml) of Candida albicans suspension.On the 10th day both sides of the posterior foot pad were measured;then the foot pads were injected with additional 50 μl of the Candida albicans suspension.Twenty-four hours after the injection,the thickness of each foot pad was measured,and immunosuppression rate was calculated.Finally,the mice were sacrificed and skin samples were obtained from the back of these mice followed by the examination of CDla, CD80 and CD86 expression by Western blot.Resets The thickness of edema in foot pads was 0.41±0.38 mm,0.21±0.23 mm and 0.30 ± 0.25 mm in group 1,3 and 4,respectively,significantly higher than in group 5 and 2(0.04±0.03 mm,0.14±0.12 mm,respectively,all P<0.05),while no significant difference was observed between the group 3 and 4(P>0.05).Significant differences were observed in the immunosuppression rate between group 2,3 and 4(73.0%±11.3%,54.1%±6.4%,29.7%±7.5%,respectively,all P<0.01).Western blot revealed a significant increment in the expression of CDla protein in group 1 compared with group 2 as well as in the expression of CD86 protein in group 1 and group 3 compamd with group 2 and group 5(all P<0.05),but no statistical difference was observed between the other groups in the expression level of CDla,CD80 or CD86(P>0.05).Conclusions The exposure to sub-erythema dose of UV can induce DTH,and sunscreens have an immunoprotective effect in this process.Epidermal Langerhans cells are not essential for UV-induced immunosuppression.