ve To establish a method for determination of arsenic in drinking water. Methods The contents of arsenic in water samples were determined directly by graphite furnace atomic absorption spectrophotome-try with masking agent of palladium. The working conditions were defined as wave length of 193.7 nm, slit width of 1.3 nm, current of hollow cathode lamp of 12.0 mA; drying 40 sec at 80℃~140℃ ; ashing 20 sec at 1100℃~1200℃; atomizing 5 sec at 2 300℃; purifying 4 sec at 2 600℃ . Results The linear relationship was 10~200?g/ L ar-senic. The average recovery rates of water samples at concentrations of 50 ?g/ L and 150?g/ L arsenic after being added arsenic standard solutions were 100.7% and 103.6% respectively, and sensitivity reached 10?g/ L. The cor-relation coefficient were 0.9954~0.999 7 obtained from 6 randomly repeated determination of standard curve. The metal ions coexisting in determined water samples didn't interfere the determination of arsenic under the application of common uncoated graphite tube. The 0.2% aluminum didn't disturb the determination of arsenic also. Conclusion This method could be applied in the determination of arsenic in water, especially could be applied in the direct deter-mination of arsenic in more clear water samples.

Objective To investigate the effect of astilbin on expression of CTLA-4 in activated T cells of mouse heart transplantation model with acute rejection.Methods Cardiomyocytes of BALB/ c mouse and spleen cells of C57BL/6 mouse were separated.The cardiomyocytes(2?10~5/ml)as irri- tation cells and spleen cells(1?10~6/ml)as responsers were mixed and cultured.The model of mouse heart transplantation with acute rejection in vitro was established.Three groups were set up:control group,Astilbin(15/?g/ml) group,Astilbin+anti-CTLA-4 mAb 9H10 (30?g/ml)group.Apoptosis of T cells was observed by TUNEL.The expression of CTLA-4 in activated T cells was detected by RT-PCR and Western blot.Results Apoptosis indexes of activated T cells in Astilbin group were sig- nificantly higher than those in the control group(73.4%?12.5% vs 35.1%?9.2%,P＜0.01). The expression of CTLA-4 in Astilbin group was significantly higher than control group(P＜0.01), but there was no apparently difference between control group and Astilbin+CTLA-4 mAb group(P＞0.05).Conclusion Astilbin induces apoptosis of activated T cells in heart transplantation,which may be partially related to its enhanced expression of CTLA-4.

Objective To assess the value of upper airway narrowing with MSCT under quiet respiration in patients with the obstructive sleep apnea-hypopnea syndrome (OSAHS). Methods CT scan of upper airway was performed in 63 patients with OSAHS during inspiration, expiration and quiet respiration respectively with 16-slice spiral CT. The state of the soft palate, the area of the smallest cross-sectional area of retropalatal and retroglossal space of the upper airway during the different respiratory phase were compared. The correlation between these dimensions and the polysomnography (PSG) results were analyzed. Results Some particular pattern of events occurred in 14 patients during the different phase of respiration, such as hooking of the soft palate, raising of the soft palate, artifacts, etc. These events occurred more often in the expiration phase. The cross-sectional area of the retropalatal space was the smallest during quiet breathing. There were statistically significant differences in the smallest cross-sectional area of retropalatal space among different phases of respiration (F=4.602, P＜0.05), also between inspiration and expiration, quiet breathing groups. No statistically significant difference was found between expiration and quiet breathing, nor in the smallest cross-sectional areas of retroglossal space among the three groups (P＞0.05). There was positive correlation between the smallest area of retropalatal space and LSaO_2 in quiet breathing and expiration groups (r=0.511, 0.300, P＜0.05). Conclusion MSCT scan of upper airway may be a better way to evaluate upper airway narrowing under quiet breathing when patients failed to carry out the required mode (keeping exhalation) or some undesirable events occurred.

BACKGROUND:The resin infiltration technique for masking white spot lesions has obtained a result superior to the conventional remineralization. Up to now, few studies have evaluated the color of carious incipient lesions treated with the resin infiltration.
OBJECTIVE:To assess the color change of caries incipient lesions in the enamel treated with resin infiltration.
METHODS: Forty-eight extracted teeth were exposed to demineralizing solution for 4 weeks to establish artificial caries models. Then artificial caries models were treated with resin infiltration and randomized into four groups: these specimens were immersed in red wine, coffee, tea and artificial saliva for 2 and 4 weeks, respectively. The base line color was evaluated by spectrophotometer. The variation in color (ΔE) was analyzed by one-way analysis of variance and Tukey’s tests.
RESULTS AND CONCLUSION:Al specimens underwent color and lightness changes, irrespective of immersion media. After 2 weeks of immersion, ΔE values were ranked as folows: red wine > coffee > tea > artificial saliva, and there were significant differences between four groups (P < 0.05). After 4 weeks of immersion,ΔE values were ranked as folows: red wine≈ coffee > tea > artificial saliva, and there were significant differences between four groups (P < 0.05) but not between the red wine and coffee groups (P > 0.05). Significant changes in the color were found in the red wine and coffee groups at different time after immersion (P < 0.05). Immersed in red wine, coffee and tea, the?E value was > 3.7, which is not acceptable in clinic. These findings indicate that the color stability of carious incipient lesions located in the enamel treated with resin infiltration is associated with the soak solution and soak time. In addition, immersion in red wine and coffee results in significantly increased color alteration (ΔE) compared with the artificial saliva.

Objectives To evaluate efficacy of intravenous thrombolysis with urokinase(UK) for treatment of patients with acute cerebral infarction (ACI)at early stage.Methods 76 patients with ACI onseting within 6 hours were randomizd into two groups,UK regime group and control group.UK group was given included 250 000 units UK IV injection and then 1500 000 units IV dripping.Neurologic defect scoring system was used to evaluate patients' responses at admission,and 24 hours,one week,two weeks as well as 4 weeks after treatment.Results Significant improvements of neurologic defect scorings happened in both groups between 24 hours and 4 weeks after treatment.As for the improvement of neurologic defect scoring,there were significant defferences between both groups at 24 hours,1st week,2nd weeks and 4th weeks of post dosing respectively(P

Objective To study the effect of Bcl-2 gene transfer on apoptosis of myocardium in mice heart transplantation rejection. Methods Models of mice neck heterotopic heart transplantation were set up, and were randomly divided into transplant group, Bcl-2 group and control group. Bcl-2 was transfected into isolated donor heart, and after 1 hour the donor heart was transplanted to the recipient. At 1st,3rd,5th and 7th day after transplantation, apoptotic index was evalulated by the percentage of mycardial cells with TUNEL positive staining and the protein expression of Bcl-2 was measured by immunohistochemical method. Results The apoptotic myocardial cells significantly increased at 3rd day and the apoptotic peak was at 7th day after transplantation in transplant group.The protein expression of Bcl-2 in Bcl-2 group significantly increased at 3rd day, the expression peak was at 5th day after transplantation, and high level expression remained at 7th day. Apoptosis indices of mycardial cells in Bcl-2 group were significantly lower than those in transplant group (P

OBJECTIVE To probe how to avoid the complication after intravenous infusion for the elders. METHODS The cause of the complication in infusion therapy for the elders with a total of 80 cases in the past three years was analyzed retrospectively. RESULTS Among the complications after intravenous infusion for 80 elders,leakage injury accounted for 47 cases(58.5%), and phlebitis accounted for 21 cases(26.8%),respectively. CONCLUSIONS As the elders′ blood vessel wall is very thin,the intravenous infusion often causes injury,the nurses should pay more attention to operating of intravenous infusion for the elders,observing regularly,and prolonging the time for pressing the pinprick after pulling out the dropper,in order to reduce the coming of injury.

Chronic hepatitis B is a world-wide health problem and now at least 250 million people have been infected with hepatitis B virus. Current treatment of hepatitis B rarely achieves a cure because the viral replication template which called covalently closed circular DNA (cccDNA) are resistant to conventional therapies. The phenotype and function of natural killer cells from chronic hepatitis B patients are different to those from acute hepatitis B patients, suggesting that the function of NK cells may be related to clearance of HBV. Some studies have suggested that the differentiation, development and activation of natural killer cells are controlled by the mammalian target of rapamycin. The present review will mainly focus on the biology of hepatitis B virus, the differentiation and development of natural killer cells, and the progress of metabolism of natural killer cells.

Tracheal intubation is an important part in clinical teaching of anesthesiology,it is also the basic skill that each anesthesiologist must master.The distinctive feature of visual technology is intuitive visual,meaning operation process and anatomical structure can be seen directly and clearly.Our department tried to teach tracheal intubation with visual technology.Teachers firstly demonstrated standard incubation with video laryngoscope and explained the related basic theoretical knowledge.Then students practiced the intubation in models until becoming skilled,finally students can practice in real patients.The teaching effect of the modified method was better compared with that of traditional method.

Objective To explore the expression and clinical significance of IL-12 in acute cardiac allograft rejection in rats.Methods Two groups of SD rats received cervical heterotopic heart transplantation from allogeneic Wistar or syngeneic SD rats.The cardiac grafts were harvested at 1,3,5,and 7 days after transplantation and detected for the expression of IL-12 mRNA by reverse transcriptional polymerase chain reaction(RT-PCR).Results With the posttransplantation day delayed,the expression of IL-12 mRNA was significantly increased in allogeneic transplant group(P