Using Xanthine-Xanthine Oxidase system to generate superoxide ani-on, using H2O2 -Fe2 + system to generate hydroxyl radical, the role of scavenging oxygen free radical by Miltiorrhiza was studied by electron paramagnetic resonance and spin trapping. The result suggested that the scavenging rate of hydroxyl radical by Salvia Miltiorrhiza injection is 65%, and that of superoxide anion is 100%. This result suggests that scavenging cytotoxic oxygen free radicals may be one of important pharmacological mechanism of Salvia Miltiorrhiza.

Objective:To study the effects of SiO2 nanoparticles on the organs of mice in vivo after intratracheal instillation, and to provide the basis for safety evaluation of SiO2 nanoparticles. Methods:Forty female BALB/c mice aged 6-8 weeks were randomly divided into control group (saline), low dose of SiO2 group (7 mg·kg-1), middle dose of SiO2 group (21 mg·kg-1), and high dose of SiO2 group (35 mg·kg-1).1 and 15 d after five times of non-exposed intratracheal instilation infection (once every 3 d), the mice were sacrificed and the left lungs,the right kidneys, livers, hearts and spleens were collected and embedded in paraffin.The morphology of tissue sections was observed under light microscope after hematoxylin-eosin (HE) staining.The eyeball blood was obtained and the biochemical indicators of liver and kidndy functions were detected.Results:Compared with control group, there were alveolar interval thickening, inflammatory cell infiltration, and a small amount of small arterial thrombosis in the lungs;granulomatous inflammatory cell infiltration and a small amount of focal necrosis of liver cells in the livers;red pulp enlargement, hyperemia, and more visibly scattered megakaryocytes in the spleens in SiO2 nanoparticles groups in a dose-dependent manner, especially in middle and high doses of SiO2 groups.After 15 d of injection, the damages alleviated with the prolongation of time.There was some inflammatory cell infiltration in the kidney tissue of the mice in SiO2 nanoparticle groups.The biochemical indicator detection results showed that alanine aminotransferase(ALT) and aspartate transaminase(AST) levels in SiO2 nanoparticles groups varied, suggesting the liver cell damages were at different degrees;the changes of urea nitrogen(BUN) and creatinine(Cr) levels in SiO2 nanoparticle groups remindered the kidney function alteration, but there were no obvious dose-and time-dependent effects.Conclusion:Intratracheal instillation of SiO2 nanoparticles can influence the major organs of the mice and mainly displays in the inflammation and injuries in the lung, liver, and spleen.

OBJECTIVE: To study the influence caused by the different intervention opportunity and frequencies in treatment chronic sinusitis after endoscopic sinus surgery. METHOD: Eighty patients with chronic sinusitis and nasal polyps were divided into group A and group B randomly. First postoperative management of functional endoscopic sinus surgery was taken in one week after operation, a week one time at first and second month, two weeks one time at third and fourth month, one month one time after fifth month, in group A. First postoperative management of functional endoscopic sinus surgery was taken in two weeks after operation, two weeks one time at first and second month, one month one time from third month to fifth month, two month one time after sixth month, in group B. The nasal middle meatus mucociliary transport rate (MTR) was measured by saccharin method at third month, sixth month and twelfth month, the rate of epithelialization was measured at third months and the efficiency rate was measured at twelfth months after operation. RESULT: All results were no significant difference. CONCLUSION Appropriate extended postoperative management time and decrease intervention frequencies were not influence the therapeutic effect of endoscopic surgery for chronic sinusitis and/or nasal polyps.
Adolescent ; Adult ; Aged ; Chronic Disease ; Endoscopy ; methods ; Female ; Humans ; Male ; Middle Aged ; Nasal Polyps ; surgery ; Nitric Oxide Synthase Type II ; metabolism ; Otorhinolaryngologic Surgical Procedures ; Postoperative Period ; Sinusitis ; surgery ; Time Factors ; Young Adult

Studies about the radioactivity level in whole diet of Chinese residents were presented in this paper. Related method and result were analyzed and compared between different countries. A summary and an outlook of this field were put forward in the end. This study estimated the radioactivity level in whole diet of Chinese residents and those in other countries. It also provided information for food safety and radiation protection of the public.

Objective: To explore the effect of change in occupational internal dose coefficients on estimation of the in- ternal exposure dose of radiation workers. Methods: Forty-one radionuclides were selected as the research objects, and their new and old occupational internal dose coefficients were summarized. The change in internal dose coefficients was analyzed by calculating the ratios of dose coefficients and using the frequency distribution of ratios. Results: The occupational in- ternal dose coefficients of the 41 radionuclides analyzed had all changed, with ratios ranging from 0.1 to 4.5, and the maxim- um difference reaching 10 times (when the ratio was equal to 0.1). Conclusion It is recommended to revise the national standards concerning occupational internal dose coefficients in time and update the occupational internal dose coefficients, so as to better monitor the occupational health of radiation workers.

Objective To study the variation in net count rates of natural radionuclides in background of gamma-ray spectrometer,so as to provide a scientific basis for reducing the effect of background fluctuations on sample measurement.Methods The unscheduled background spectrum obtained using two high-purity gamma-ray spectrometers during 2013-2017 were collected,and then the net count rates of 210pb,234Th,212Pb,214pb,208Tl,214Bi,228Ac and 40K were calculated and analyzed by aid of statistical method.Results There was a significant difference in the net count rates of 210Pb,234Th,212Pb,214Pb,208Tl,214Bi,228Ac and 40K in the background spectrum of gamma-ray spectrometer,and the net count rates of 214Pb,214Bi and 40K was significantly higher than those of 210Pb,234Th,212pb,208Tl and 228Ac.There were no significant differences in the net count rates of these eight natural radionuclides from 2013 to 2017,respectively (P ＞ O.05).However,the coefficients of variation in the net count rates for 214pb and 214Bi were both greater than 50％.Conclusions When the activity concentration of natural radionuclides is determined in a sample by gamma-ray spectrometer,it is critical to subtract the background spectrum obtained recently to ensure the accuracy of the measurement,especially for the low activity concentration of natural radionuclide to be measured.

This paper briefly introduces the main content of IAEA Safety Reports Series No. 114. The aim is to further understand the status and development of exposure due to radionuclides in food other than during a nuclear or radiological emergency, as well as to provide references for the revision and improvement of the limited concentration standard of radioactive substances in food in China.

Objective:To recommend reference composition for sourceless efficiency calibration of food gamma spectrometry by analyzing the composition of common foods based on a combination of sourceless efficiency calibration and active validation.Methods:Thirty common types of food samples in countrywide monitoring of radioactively contaminated foods were analyzed to statistically determine the reference composition of grains and vegetables. Combined with the parameters provided for white quinoa standard source, LabSOCS was applied to carry out the simulation of sourceless efficiency for its different compositions, and to calculate its measured activity, and analyzing its relative deviation to the those given in the certificate.Results:The analytical result of these 30 types of food samples showed that the five elements C, H, O, N and S accounted for 77.0%-93.7% of the food composition, being the main component of these samples. By applying white quinoa′s components and grain-based reference components to the simulation of the sourceless efficiency of white quinoa standard sources, the relative deviations of activity calculations to their certificated activities were in the range of 0.37%-5.86% and 0.38%-5.87% in absolute value, respectively.Conclusions:The white quinoa′s composition and the grain reference composition were applied to the sourceless efficiency simulation of the white quinoa standard source, and the relative deviation of the calculated measured activity to the activity of the standard source certificate was basically identical, so that if the gamma spectrometry-based sourceless efficiency simulation is used to measure the unknown composition of the food samples and it is inconvenient to carry out the analysis of the food samples′ compositions, especially in the case of emergency, it can be referred to the use of the reference compositions obtained in the present study.

Objective:To improve the radionuclide measurement technology by γ-spectrometry throuth a review of the intercomparisons between China and Japan results over the past 20 years.Methods:Before the beginning of each intercomparison, one of participating laboratories was agreed to be responsible for preparing the samples for the intercomparison. By intercomparison of the measurement results arnong the laboratories some potential problems during the sample pre-trement or analysis were found and solved.Results:The intercomparisons had been carried out for 11 times over the past 20 years. Totally 290 measured and analyzed results had been obtained from 20 samples of six categories. The proportion 95.5% of measurement results were in agreement with each other within the deviation range.Conclusions:The measuring and analytical capability of the laboratories involved were tested. The intercomparisons also provide long-term quality assurance measures for the radionuclide measurement and analysis in each laboratory.

Objective:To measure the influencing factors associated with the analysis of 226Ra gamma spectra in order to obtain more acurate and precise measuring result on a basis of further optimizing the gamma spectrometry method for 226Ra activity. Methods:A laboratory-based HPGe gamma spectrometer was used to carry out the studies on tracking measurement of sample sealing time, measurement of background fluctuation with lead shielding, analytical method, and selection of characteristic gamma ray energy peak of its daughter nuclides in 226Ra measurement. Results:After the sample was sealed for 12 d, the decay products of 226Ra- 222Rn basically reached equilibrium. The day and night fluctuations of 222Rn in the shielded lead room were obvious but had no obvious regularity. The way of filling nitrogen into the shielded lead room could reduce or avoid the influence of background fluctuations. For 31 soil samples measured after 23 days of sealing, the result of using the efficiency curve method showed that the 226Ra result calculated from the 351.9 keV energy peak were generally higher than the 609.3 keV energy peak, and the higher ratio ranged from 8.0% to 20.7%. The result of relative comparison method showed that the deviation ratio of the two peaks ranged from -4.1 % to 10.3 %. Conclusions:It is recommended to consider the uncertainty attributed from decay equilibrium about 4 % of measured at 12 d after the sample is sealed. When filling nitrogen through the shielded lead chamber to avoid background fluctuations, attention must be paid to the matching relationship between the volume of the lead chamber and the nitrogen filling flow. When the efficiency curve method is used to analyze the activity of 226Ra, the 214Bi ( 609.3 keV ) energy peak has the effect of cascade coincidence addition, so 214Bi(609.3 keV) energy peak should be avoided. When the relative comparison method is used to analyze the activity of 226Ra, both two energy peaks of 214Pb ( 351.9 keV ) and 214Bi ( 609.3 keV ) can be used.