Objective To assess the accuracy and precision of γ-spectrometry analysis, and to obtain accurate and valid measurement results in the middle term and long term. Methods A nationwide intercomparison on gamma-ray spectrometry measurement of activity concentration of 226Ra, 232Th and 40K in soil and building material was organized by National Institute for Radiological Protection( NIRP) , China CDC. Results 15 laboratories participated in this intercomparison, with 13 laboratories produced acceptable results. Only 2 laboratories were classified as " not acceptable" , including one for inappropriate accuracy in determination of 40K and another for inappropriate precision determination of 226Ra in both kinds of the samples. Through comment and discussion, the second round intercomparison got satisfactory results. Conclusions The overall measurement results of samples for intercomparison are in close agreement with the reference values. Most of the laboratories involved in the intercomparison have good ability in γ-spectrometry analysis.

OBJECTIVE: To characterize morphology and drug release kinetics of protein-loaded poly(?-caprolactone)/poly(ethylene glycol)/poly(?-caprolactone) amphiphilic block copolymeric (PCE) microspheres, and elucidate the mechanistic details regarding protein release. METHODS: BSA-loaded PCE microspheres were prepared using a water-in-oil-in-water, followed by solvent evaporation. Morphology of the polymer microspheres was observed using scanning electron microscopy. Protein loading capacity and encapsulation efficiency were determined by extracting the proteins from the microspheres and measured using MicroBCA method. Protein release kinetics was characterized by cumulative release against the date of release incubation. RESULTS: The protein-loaded PCE microspheres were spherical and possess smooth surface under SEM. Protein loading capacity and encapsulation efficiency in the microspheres were independent of PCE molecular weight. However, the kinetic features of the protein release varied significantly with PCE molecular weight, suggesting a diffusion-degradation combined release mechanism. For the microspheres made of larger molecular weight PCE 4000, the portion of protein release attributed to diffusion from the polymer matrix was remarkably less than that from microspheres of small molecular weight PCE. In vitro release profile can be simulated using a diffusion-degradation model(Q=k1t1/2+k2t+k3t2+k4t3)(r=0.997). CONCLUSION: PCE microsphere formulation can offer sustainedrelease of proteins with initial burst and incomplete release reduced to acceptable level.

Objective To measure and analyze the radioactivity level of 210Pb in outdoor air in Beijing in spring.Methods Portable high flow air samplers were used to collect outdoor air at the ground level to analyze the 210Pb radioactivity in the aerosol filter samples using a laboratory-based high purity germanium (HPGe) γ spectrometer.Results The activity concentration of 210Pb outdoors ranged from 267.2 to 1 697.6 μBq/m3,with an average of (878.7 ± 386.7) μBq/m3.Statistical analysis showed that the activity concentrations 210Pb of outdoors varied with variable air quality.Conclusions The activity concentrations of 210Pb outdoors are detectable in Beijing,varying considerably but within the normal range.

Objective To explore the effeetiviness of the method of LabSOCS(Laboratory sourceless calibration software)efficiency calibration in laboratory rapid analysis for emergency monitoring of nuclear incidents.Methods The detection efficiency of three kinds of environmental samples in emergency monitoring Wag calculated bY using the LabSOCS efficiency calibration method,and compared with the values that were obtained by way of radioactive source calibration method.Results The maximum relative deviation of the detection efficiency between the two methods was less than 15%,and the values with relative deviation less than 5%accounted for 70%.Conclusions The LabSOCS efficiency calibration method might take the place of radioactive source efficiency calibration method,and meet the requirement of rapid analysis in emergency monitoring of the nuclear incidents.

Objective To measure the current environmental radioactivity levels in some districts of Yunnan Province,and to estimate the external doses to local residents.Methods The surface soil,aerosol and water samples were collected and analyzed by HPGe gamma spectrometry.Based on the estimation model selected by Ministry of Health in the nationwide soil survey,the doses to local residents from 238U,226Ra,232Th,40K and 137Cs in environmental samples were estimated.CARI-6 software issued by FAA (Federal Aviation Administration ) was used to estimate cosmic radiation dose to the local population.Results The external annual dose rate to the local people was 1.13 mSv per year,of which 0.52 mSv per year was contributed by natural radionuclides in soil,0.6 μ Sv per year by 137 Cs in soil and 0.61 mSv per year by cosmic radiation.Conclusions The cosmic radiation and natural radionuclides in soil might contribute 99.95％ of external exposure dose,while artificial radionuclide 137Cs contribute 0.05％ of external exposure dose.

Objective To test a full range of processes of sample collection,preparation,measurement and analysis by conducting the intercomparison of gamma-ray spectrometry measurement and analysis of radionuclides among key laboratories,so as to facilitate the development of gamma-ray spectrometry measurement and analysis technology.Methods To complete the collection and preparation of soil samples by Chinese Center for Disease Control and Prevention (CDC) laboratory and to measure and analyze the content in two soil samples of 214Pb,214Bi,208TI,228Ac,40K and 137Cs by three laboratories using gamma-ray spectrometry.Results The value calculated by any two laboratories were less than 1 in terms of assessment standards agreed by these three laboratories and based on the activity concentrations and the total uncertainty reported from them.The measurement results from our lab were acceptable.Conclusions Measurement results from these three laboratories are in agreement to some extent.This intercomparison activity has tested the analytical ability of the three laboratories and raised the level of our laboratory in testing homogeneity of sample preparation.

Objective To determine the activity concentration of radionuclides for 137Cs and 40K in edible wild mushrooms,and to evaluate the extent of radioactive contamination and ingestion doses to adults from consumption of these wild mushrooms.Methods A total of 33 samples for 18 edible wild mushroom species were collected from natural forest Mangshi,Yunnan province.The activity concentrations of 137Cs and 40K were analyzed by using high-purity germanium (HPGe) gamma spectrometry.Results Except.for one sample that was below the MDA,137Cs artificial radionuclides were detected in other 32 samples,with activity concentration of 137Cs in the range of 0.45-339.58 Bq/kg (dry weight) and an average of 25.47 Bq/kg (dry weight).In regards to 40K in edible mushrooms,all species presented the activity concentrations for this radionuclide and the levels varied from 453.4 to 1 882.6 Bq/kg (dry weight),with an average of 815.1 Bq/kg (dry weight).After species of mushroom with only one sample were eliminated,there was significant difference for 137Cs(F =21.13,P ＜ 0.05) among 6 species of mushroom named Gomphus floccosus (Schw.) Sing.,Boletus edulis bull,Boletus edulis bull,Tylopllus bolloul (Peck) Sing.,Lentinus edodes (Berk.) Sing.and Boletus brunneissimus W.F.Chin,but without significant difference for 40K.Conclusions These 6 different mushroom species have different capacity to retain radionuclides of 137Cs in soil.These wild mushrooms,such as Gomphus floccosus (Schw.) Sing.and Lentinus edodes (Berk.) Sing.have large affinity ability for radionuclides137Cs.The effective dose to adults attributable to consuming these kinds of mushrooms is small and below the level that could cause harm.

Objective To determine the artificial radionuclides levels in environmental samples collected in some areas of China following the Japanese Fukushima nuclear accident,and to evaluate the extent of radioactive contamination.Methods A total of 118 samples including aerosol,water,soil and biological samples were collected and the activity concentrations of 131I, 137Cs and other artificial radionuclides were analyzed by using high-purity germanium (HPGe) γ spectrometry.Results Artificial radionuclides 131I,134Cs,137Cs and 136Cs were detected in the aerosol samples on 2 April,2011 and the activity concentrations were 1720,247,289,and 23 μBq/m3,respectively.Trace amount of 131I was detected in one sample of rain water and two samples of surface soil with concentrations of 2.08 Bq/L,1.82 and 0.59 Bq/kg,respectively.131I was also detected in 18 vegetable samples which were collected from 2 April to 13 April with the range of 0.55 -2.68 Bq/kg.Neither abnormal concentrations of 131I nor 137Cs was detected in milk,drinking water,sea water and marine products samples.Conclusions During the Fukushima nuclear accident,although minute quantities of radionuclides were detected in some samples collected in China,the effective dose for adults attributed to the nuclear accident is extremely small and significantly below the level that could cause harm to the public.

Objective To detect artificial radionuclide content in the spinach and soil in open air vegetable garden in Beijing during Fukushima nuclear accident and to study the radioactive contamination characteristics of the samples.Methods 6 spinach samples and 3 soil samples in open air vegetable garden were obtained through continuously sampling.High-purity germanium (HPGe) γ spectrometry was used to analyze activity concentrations of artificial radionuclide131 Ⅰ etc in these samples.Results Artificial radionuclide 131Ⅰ was detected in the 6 open air spinach samples.Artificial radionuclide 137Cs was detected in 3 vegetable garden soil samples,trace amount of 131 Ⅰ was detected in 1 open-air surface soil sample alone.Conclusions Following the Fukushima nuclear accident,spinach in Beijing's open-air vegetable garden was slightly polluted by artificial radionuclide 131 Ⅰ,with the highest values of pollution appeared around April 4,2011,but it could not cause harm to human health.

Aim To explore the anti-proliferation effects of curcumin trinicotinate ( CurTn ) on vascular smooth muscle cell ( VSMC ) and its mechanism. Methods The cells were cultured in DMEM supple-mented with 10% fetal bovine serum. MTT assay was used to examine cell proliferation. FCM was used to observe cell cycle. The expressions of PCNA, Cy-clinD1 and p-ERK1/2 were analyzed using Western blot. Results CurTn could inhibit the proliferation of VSMC and showed a certain amount-time relationship. What’ s more, CurTn could increase the G1 phase pro-portion of cell, decrease the S phase proportion and the expression level of PCNA protein. It was also found that CurTn significantly inhibit the protein expression of p-ERK1/2 and Cyclin D1 . Conclusion CurTn may inhibit the proliferation of VSMC via downregulating the expression of CyclinD1 and p-ERK1/2 .