It is generally believed that liposomes modified with polyethylene glycol (PEG) have no or lower immunogenicity. However, based on many recent literatures, when the PEGylated liposomes were repeatedly applied to the same animal, the immune responses occurred. The first injection of PEGylated liposomes resulted in a reduction in the circulation time and an increase in hepatic and splenic accumulation of the second dose of PEGylated liposomes in a time-interval, which was called "accelerated blood clearance (ABC)" phenomenon. Such immunogenicity of PEGylated liposomes presents a barrier in the research of liposomal formulations and their use in the clinics. This review focused on the definition, the method of verification, the development of the reason for ABC phenomenon, influencing factors of ABC phenomenon, and discussed if other PEGylated nanocarriers also induce ABC phenomenon.

Objective To study the differences of coagulation indices on the first day of birth in newborns with different gestational ages.Method Premature infants born in our hospital between January 2014 and December 2015 were enrolled in this study as the observational group,and they were divided into early preterm group,moderate preterm group,and late preterm group according to their gestational ages.Healthy full-term infants born during the same period were selected as the control group by 3:1 The clinicaldata and coagulation indices of the infants and their mothers in each group were compared.Result There were 44,50,71,and 52 cases in the early preterm,moderate preterm,late preterm,and control group,respectively.The prothrombin time (PT),activated partial thromboplastin time (APTT),and thrombin time (TT) of the premature infants in the early preterm group,moderate preterm group,and late preterm group were all longer than those of the control group [PT:(16.1 ±4.3) s,(16.8 ±4.9) s,(15.8 ±4.8) s,vs.(13.0±1.3)s;APTT:(88.3±38.1) s,(93.5±37.7) s,(91.0±32.3) s,vs.(66.0±17.8) s;TT:(25.4 ±4.6) s,(25.1 ±5.5) s,(25.0 ±3.3) s,vs.(24.0 ±3.3) s;all P＜0.05].The fibrinogen level of the premature newborns in three groups were all lower than that of the full-term infants in the control group [(1.11 ± 0.46) g/L,(1.12 ± 0.44) g/L,(1.12 ± 0.45) g/L vs.(1.28 ± 0.37) g/L,P ＜ 0.05].The differences of all the indices among the three groups of premature infants were all not statistically significant (P ＞ 0.05).The comparison of the coagulation indices of the mothers of the newborns from all four groups showed no significant differences (P ＞ 0.05).Conclusion Compared with full-term infants,preterm infants showed significantly poorer coagulation function on the first day of birth.However,there were no significant differences in coagulation indices among preterm infants of different gestational ages.

Objective:To study the application of ammonium cerium sulfate spectrophotometry for determination of iodide in water.Methods:Ammonium cerium sulfate spectrophotometry was used to determine the iodine content of tap water and source water in the range of 0 - 20 and 0 - 200 μg/L iodine concentration. The effect of the method was verified in terms of linear range, detection limit, precision and accuracy.Results:In the range of 0 - 20 and 0 - 200 μg/L iodine concentration, the absolute values of linear correlation coefficients were > 0.999 0; the detection limits were 0.18 and 1.02 μg/L, respectively; the coefficient of variation of low, medium and high iodine concentrations in tap water and source water was less than 5%. In the range of 0 - 20 μg/L iodine concentration, the spiked recovery rates of tap water and source water were 90.33% - 110.46% and 92.21% - 102.82%, respectively; in the range of 0 - 200 μg/L iodine concentration, the spiked recovery rates of tap water and source water were 90.14% - 102.62% and 91.36% - 106.18%, respectively. The national first level standard materials GBW09113g and GBW09114g were tested, and the results of water iodine determination were within the given range of the standard materials.Conclusion:Ammonium cerium sulfate spectrophotometry has a wide linear range, high accuracy, and good precision, making it suitable for widespread application in grassroots areas.

Objective:To study the application of antimony cerium catalytic spectrophotometry using a fully automatic biochemical analyzer (hereinafter referred to as this method) in the determination of water iodine.Methods:Based on the principle of antimony cerium reoxidation reduction reaction catalyzed by iodine, the iodine content in water was determined in the range of 0 - 100 μg/L iodine mass concentration. The detection limit, precision and accuracy (determination of standard substances GBW09113j and GBW09114j for iodine composition analysis in water and the experiment of standard recovery) of this method were verified. This method was compared with the arsenic and cerium catalytic spectrophotometry recommended by the National Reference Laboratory for Iodine Deficiency Disorders.Results:Within the range of 0 - 100 μg/L iodine mass concentration, the qualitative and quantitative detection limits of this method were 0.81 and 2.70 μg/L, respectively (sampling quantity was 35 μl). In the precision experiment, the relative standard deviation of water samples with different iodine mass concentrations ranged from 1.2% to 4.0%. The determination results of the standard substances GBW09113j and GBW09114j for iodine composition analysis in water were both within the given standard value range. The standard recovery rates of water samples with low, medium and high iodine mass concentrations ranged from 101.0% to 106.0%, and the total average standard recovery rate was 103.2%. The results of the method comparison experiment showed that there was no statistically significant difference in the results of water iodine determination between the two methods ( t = - 0.78, P = 0.779). Conclusion:This method has a low detection limit, high precision and good accuracy, making it suitable for the detection of large quantities of samples in the monitoring of iodine deficiency disorders.

Objective:To establish a hydride generation atomic fluorescence method using ammonium persulfate as the digestion reagent for determination of arsenic in urine (hereinafter referred to as this method).Methods:The collected urine samples with ammonium persulfate were heated and digested on the tubular electric heating automatic control constant temperature digester (60 holes), with 5% hydrochloric acid solution as reaction medium and current carrier and 1.5% potassium borohydride solution as reducing agent. Arsenic content was determined with a four-channel atomic fluorescence spectrometer. The arsenic standard solution of 0 - 10 μg/L was prepared to determine the standard curve of this method, and the method was evaluated from the detection limit, linear range, correlation coefficient, precision, standard addition recovery experiment, and urine arsenic quality control sample detection. The standard method "Determination of Arsenic in Urine by Hydride Generation Atomic Fluorescence Spectrometry" (WS/T 474-2015, referred to as the standard method) was used for comparison experiments.Results:When the sampling volume was 1 ml, the detection limit of this method (digest with 1 ml 1.5 mol/L ammonium persulfate) was 0.03 μg/L. In the range of arsenic content from 0 - 10 μg/L, the linear relationship between arsenic content and fluorescence intensity was good, and the correlation coefficients ( r) were all 0.999 9. The relative standard deviations( RSD) of the three replicates of urine samples with different concentrations were 1.00%, 0.89% and 0.49%, respectively. Urine arsenic quality control samples were tested, and the test results were all within the range of public values; the overall average recovery was 102.29%, and the recovery range was 92.10% - 108.15%. Compared with the standard method in the determination results of 20 urine samples, the difference was not statistically significant ( t = - 0.40, P > 0.05). Conclusions:The hydride generation atomic fluorescence spectrometry using ammonium persulfate as digestion reagent for the determination of arsenic in urine has the advantages of low detection limit, good precision, high accuracy, small amount of sampling and digestion reagent, simple operation, and less harmful gas generation in sample pretreatment. It is suitable for rapid determination of arsenic in urine in large quantities.