Objective To establish a method for determination of trace lead in alginate sodium.Method The lead in the samples was determined by fluorescence spectroscopy after been digested by hydrothermal decomposition.Results The detection limit of lead was 2.71?10-2?g?mL-1.The relative standard deviation of the three samples were 4.06%,1.57% and 2.12% respectively,the average recovery was 88.32%～100.8%.Conclusion The method had the advantages of simple operation,higher precision,higher sensitivity and repeatability and was suitable for the determination of trace lead in the alginate sodium

Objective Rheological properties and gelation properties of agar were investigated. Methods The gelling point,melting point and the gel strength of agar were detected with MCR101 rheometer and TA texture testing instrument. Results and Conclusion Rheological properties of agar were affected by its concentration ,temperature and the addition of salt (such as NaCl ,CaCl2) and sucrose. Apparent viscosity exhibited shear thinning behavior following the power law model. Apparent viscosity increased with the increase of concentration,and decreased with the rise of temperature. The decrease in viscosity followed an Arrhenius temperature dependence. Agar solutions exhibited typical "weak gel" properties by small strain oscillatory measurements. The results indicated that the agar solution was characterized as a gel properties ,and which could form a kind of heat reversible gel. The gelling point of agar was lower than its melting point. The gel strength of agar could be affected by its gel time,and the addition of salt (such as NaCl,CaCl2) and sucrose.

The micropipette aspiration technique was improved by selecting the uniform cells in round shape (UCR) from a number of adhered cells on the testing surface so as to measure the adhesion forces during the initial adhesion stage. Silk fibroin film and silk fibroin/fucoidan film were used as testing substrates. The testing results revealed that the modified micropipette method was more rapid for testing. The tendency of cell adhesion force on different materials surface under different conditions remained unchanged. The testing results showed good reproducibility. It was easy to distinguish small differences in the adhesiveness of endothelial cell on the silk fibroin based materials, thus exhibiting the high sensitivity of the improved method.
Cell Adhesion ; physiology ; Cells, Cultured ; Endothelial Cells ; cytology ; Fibroins ; Humans ; Umbilical Veins ; cytology

Objective To observe the effects of percutaneous endoscopic gastrostomy (PEG)on mortality and complications in patients with persistent dysphagia after stroke using a points scoring system for selecting PEG indication.Methods A total of 75 patients were divided into low score group without PEG,high score group without PEG and low score group with PEG (n=25 each).The follow-up period was 18 months,and the differences in complications,mortalities and survival periods among groups were compared.Results The number of times of aspiration pneumonia was (1.36± 1.44) in low score group,(1.96±2.28) in high score group,(0.36±0.64) in low score group with PEG,with statistically significant differences among three groups (H=7.148,P=0.028).No difference in the morbidity of aspiration pneumonia was found between low score group and high score group (P=0.189).The number of times of aspiration pneumonia was decreased in low score groups after PEG versus in low score group without PEG (P=0.030) and in high score group (P＜0.01).The numberof times of gastrointestinal hemorrhage was (0.48± 0.77)in low score group,(0.64± 0.91) in high score group,(0.12±0.33) in low score group with PEG,with statistically significant differences among three groups (H=5.532,P =0.063).No statistically significant difference in gastrointestinal hemorrhage was found between low score groups and low score group after PEG (P=0.430),as well as between low score group and low score group with PEG (P=0.079).The morbidity of gastrointestinal hemorrhage was lower in low score group than in high score group (P=0.012).The survival rate at the observation end was 88.0％ (22/25),52.0％ (13/25) and 92.0％ (23/25) in low score group,high score group and low score group with PEG,respectively,with statistically significant difference among the three groups (x2 =7.906,P =0.001).Kaplan-Meier survival curve showed that the survival period were longer in the low score group with or without PEG than in high score group (P＜0.01),but no statistically significant difference was found between low score groups with or without PEG (P=0.626).Conclusions The reasonable evaluation using a points-scoring system before PEG might predict the prognosis of such patients:the higher score would indicate higher mortality.PEG operation for low score group with better condition could decrease the aspiration pneumonia and decrease gastrointestinal hemorrhage significantly,but could not prolong general survival time and decrease general mortality.