OBJECTIVE:To study the anti-oxidative effects of spirulina kinase (SPK) in vitro. METHODS:The methods of phenanthroine-Fe2+ oxidation method,DPPH and auto-oxidation of pyrogallol were used to measure the effects of different concen-trations of SPK on scavenging hydroxyl (OH-) free radical,DPPH free radical and superoxide anion (O2-) free radical;IC50 of SPK was calculated. Prussian blue reaction was used to determine total reducing ability(by absorbance)of different concentrations of SPK to Fe3+. Vitamin C(VC)was used as positive control in above trials. RESULTS:SPK could eliminate the OH-free radical, DPPH free radical and O2- free radical in concentration-dependant manner,and the maximum elimination rate of SPK to OH- free radical and DPPH free radical were 86.82% and 78.98%(IC50 were 54.31,0.636 g/L),which were higher than VC (64.77%, 73.49%). The maximum elimination rate of SPK to O2- free radical was 78.31%(IC50 was 3.918 g/L),which was lower than VC (94.14%). In reducing ability test,SPK improved absorbance in reducing ability test system,and maximum absorbance was simi-lar to VC in concentration-dependant manner. CONCLUSIONS:SPK has obvious anti-oxidant activities in vitro.

OBJECTIVE:To study the anti-coagulation effect and mechanism of fibrinolytic enzyme SNFE in sipuculus nudus, and provide reference for further development of SNFE. METHODS:40 mice were randomly divided into blank control group(nor-mal saline),Xueshuantong group(positive control,15 mg/kg)and SNFE low-dose,high-dose group(15,30 mg/kg),10 in each group. After intravenous injection in tail,tail bleeding time (BT) and clotting time (CT) were respectively determined to investi-gate the anti-coagulation effect of SNFE. After taking blood in abdominal aorta of rats,test was divided into blank control group, positive control group and SNFE low-mass concentration,medium-mass concentration,high-mass concentration groups (0.25, 0.50,1.00 mg/mL). Prothrombin time(PT),re-calcium time(PRT)(using orokinase as positive drug,100000 U/mL),and max-mum platelet aggregation rate (PAG) in 5 min under adenosine diphosphate (ADP) inducer (using asprin as positive drug,0.50 mg/mL) were respectively determined,and anti-coagulation effect mechanism of SNFE was analyzed. RESULTS:Compared with blank control group,BT,CT of mice in each group were prolonged,with statistical significance in Xueshuantong group and SNFE high-dose group (P<0.05 or P<0.01). Plasma PT of rats in positive control group,SNFE medium-dose,high-dose groups and PRT in each administration group were significantly prolonged(P<0.05 or P<0.01);and PAG in administration group was signifi-cantly reduced(P<0.01). CONCLUSIONS:The fibrinolytic enzyme SNFE in sipuculus nudus can play its anti-coagulant effect by inhibiting the activity of coagulation factors in internal and external sources and ADP-induced platelet aggregation.

Objective: To explore the hot issues and developing trend of the research of campus bulling,and to provide a reference for the research on campus bullying. Methods: The power of research, high-impact authors, highly cited journals, high-frequency keywords, and burst terms related to school bullying from the Web of Science database were analyzed using CiteSpace software. The data collection time was May 9, 2018. Results: A total of 3 561 literature data were obtained. The results showed that the country with the highest number of publications was the United States; England had the highest centrality and was in a critical position in the research. The University of Turku in Finland was the core research institution. Salmivalli C was the author of the highest publication, Olweus D was the most frequent cited author. The high-impact journal was Aggressive Behavior. In terms of high-frequency keywords, the core vocabulary such as bully, adolescence, and victim were listed. Middle school students were the most frequently studied; in the form of bullying, the frequency of violence, aggression, and cyberbully was more common; depression, mental health and health appeared more frequently in terms of bullying outcomes. Mutant words including school children, bullying, victimization, relational aggression were more common. Conclusion The research hotspots on campus bullying during the past decade include violence, gender, social support, and mental health. Bullying among college students will be a hot research topic in the future. Continued efforts should be carried out in the field of campus bullying in China.

Objective In this study ,the effect of Spirulina kinase(SPK)on hemorheology ,platelet aggregation and cAMP in acute blood stasis rats model were investigated .Methods Forty SD rats were randomly divided into normal control group ,model group ,aspirin group and the high and low dose of SPK groups .All treatments were performed by gavage once a day for 7 days .Sub-cutaneous injection of adrenalin combined with ice water bath were used to establish the acute blood stasis rat model .The whole blood viscosity ,plasma viscosity ,red blood cell hematocrit (Hct) ,erythrocyte aggregation index (EAI) ,red blood cell deformation index(DI)anderythrocyterigidityindex(ERI)weredetectedbyautomaticbloodflow speedanalyzer .Meanwhile,thelevelofcAMP was detected by ELISA method .Rat platelet aggregation induced by ADP and the maximum aggregation rate was measured by tur-bidimetry .Results Results showed that SPK could significantly decrease the whole blood viscosity ,plasma viscosity ,Hct ,EAI and platelet aggregation rate ,increase the level of cAMP compared with model group(P<0 .05) ,but had no effect on DI and ERI .Con-clusion SPK can markedly improve the abnormal changes of hemorheology in acute blood stasis rats and inhibit the platelet aggregation .

OBJECTIVE： To study the improvement effects of fibrinolytic enzyme from Sipunculus nudus （SNFE） on hemorheology disorder and vascular endothelium injury in naked acute blood stasis model rats. METHODS： SD rats were randomly divided into control group， model group， aspirin group （100 mg/kg） and SNFE high-dose and low-dose groups （2 500， 5 000     U/kg）， with 10 rats in each group. They were given relevant medicine intragastrically once a day， for consecutive 7 d. One hour after the 6th day of administration， except for control group， other groups were given adrenaline hydrochloride 0.8 mg/kg subcutaneously， and then the acute blood stasis model was induced by ice-water bath. Blood was collected from abdominal aorta 2 h after the next day. Blood rheological parameters such as whole blood viscosity （high， medium and low shear rate）， plasma viscosity， hematocrit， erythrocyte aggregation index and erythrocyte deformability index were measured by automatic rheometer. The contents of NO and ET-1 in plasma and their ratio were determined by ELISA， and the damaged degree of vascular endothelium were observed by HE staining. RESULTS： Compared with control group， whole blood viscosity of high， medium and low-shear rate， plasma viscosity， erythrocyte aggregation index and ET-1 content were increased significantly in model group， while erythrocyte deformability index， NO content and NO/ET-1 ratio were decreased significantly， with statistical significance （P＜0.05 or P＜0.01）. Compared with model group， whole blood viscosity of high， medium and low-shear rate， plasma viscosity， hematocrit， erythrocyte aggregation index and ET-1 content were decreased significantly in SNFE high-dose groups. Erythrocyte deformability index， NO content and NO/ET-1 ratio were increased significantly， with statistical significance （P＜0.05 or P＜0.01）. In SNFE low-dose group， erythrocyte deformability index and NO/ET-1 ratio were increased significantly， while ET-1 content was decreased significantly， with statistical significance （P＜0.05 or P＜0.01）. Vascular endothelial staining showed that compared with control group， the structure of aorta layers in model group was loose and disordered， the endothelial defect was incomplete， the vacuoles increased， and the endothelial damage was obvious. The endothelium of rats in each administration group was damaged to varying degrees， but the degree of injury was lighter than in model group. CONCLUSIONS： SNFE can improve hemorheological abnormalities and vascular endothelial injury in rats with acute blood stasis.

Objective:To estimate the burden of hip fractures and related factors among the Chinese middle-aged and elderly population.Methods:Based on the data of China Health and Retirement Longitudinal Study (CHARLS) in 2015, the burden of hip fractures among Chinese middle-aged and elderly population was evaluated as the years lived with disability (YLD) rate. The relationship between gender, age (45-49, 50-59, 60-69 and ≥70 years old), educational level (no education, elementary school, junior high school, high school and above), region (urban, rural), gross domestic production (GDP) per capita (low, medium and high) and geographic area (northern, eastern, south-central, northwest and southwest regions) and the YLD rate of hip fractures were analyzed, respectively.Results:Excluding items with missing basic information and hip fracture data, a total of 17,830 subjects (8,405 males and 9,425 females) were included in the study with average age 61.6±9.8 years (range 45 to 105 years). The average age in male was 61.9±9.6 years, and that in female was 61.2±10.1 years. The prevalence of hip fractures was 2.3% (410/17,830). The total YLD rate was [694/100,000 (95% Uncertainty Interval ( UI): 462/100,000, 989/100,000)]. The YLD rates were similar between male [693/100,000 (95% UI: 461/100,000, 988/100,000)] and female [696/100,000 (95% UI: 463/100,000, 992/100,000)] subgroups. The YLD rate of hip fractures was increasing with age, which reached at maximum of 1,155/100,000 (95% UI: 769/100,000, 1,646/100,000) for participants aged 70 years or above. The rate was gradually decreased with the upgrade of the educational level. The participants with high school education and above reached the lowest of 434/100,000 (95% UI: 289/100,000, 619/100,000). In addition, the YLD rate of hip fractures in rural areas [721/100,000 (95% UI: 480/100,000, 1,027/100,000)] was higher than that in urban areas [650/100,000 (95% UI: 433/100,000, 926/100,000)]. The YLD rate in areas with higher GDP per capita [545/100,000 (95% UI: 363/100,000, 777/100,000)] was lower than that in areas with lower GDP per capita [761/100,000 (95% UI: 506/100,000, 1,084/100,000)]. Moreover, the participants living in the Northwest region were with the highest YLD rate of hip fractures [1,056/100,000 (95% UI: 703/100,000, 1,506/100,000)], followed by the Southwest region [887/100,000 (95% UI: 590/ 100,000, 1,264/100,000)] and the Northeast region [317/100,000 (95% UI: 211/100,000, 452/100,000)]. Conclusion:Hip fractures exerted heavy burdens on the Chinese middle-aged and elderly population. The YLD rate of hip fractures varied according to geographical regions, greater age, rural areas, low educational levels and low GDP per capita. These related factors could affect the disease burden of hip fractures in China.

Based on the national policies, regulations and documents on residency training, this paper sorts out the historical evolution of the standardized residency training system in China, and divides its development into four stages: preliminary exploration, local pilot, national trials, and implementation. It also puts forward some practical thoughts on its development law and future trend, such aspects as that the system reform follows the top-down administrative order and indicative plan, the system pays attention to the gradual implementation on the basis of summing up practical experience, and the system needs continuous implementation and improvement from the overall perspective.