Investigation on present state of radiation protection of a 60Co irradiation facility / 中华放射医学与防护杂志

Objective:To explore the present state of radiation protection in an operational large-sized irradiation facility and the distribution of incurred radiation doses in the controlled area under abnormal conditions, and to analyze the acompanied radiation risk.Methods:With an irradiation facility in operation as the research object, the radiation doses were measured using AT1121 X and gamma dose rate meters for the soruce both in working and storage. Thermoluminescent dosimeters (TLDs) were used to measure the dose distribution in an irradiation field under abnormal conditions. The radiation safety features were checked against the several relevant national standards, with the radiation risks evaluated.Results:The radiation dose rates were in the range of 0.09-0.11 μSv/h, lower than the environmental background level whether in storage or working. Under abnormal working conditions, the radiation dose values from high to low were 1.0-101.3 Sv, 32.7-514.0 mSv and 8.7-183.2 μSv in the irradiation field, respectively. At the outside maze, the doses were close to the background level.Conclusions:The protection features of the irradiation facility meet the requirements of the relevant national standards. Under abnormal conditions, radiation could cause serious damages to the persons staying in the irradiation field. These persons were suggested to access to maze as soon as possible to reduce the exposure time, and activate the emergency protection equipments to deescalate the 60Co source onto the well.

Assessment of Radiation Shielding Requirements for Radiotherapy Room—Part 2: Radiotherapy Room of Electron Linear Accelerators (GBZ/T 201.2—2011): A survey of relevant personnel in medical institutions / 中国辐射卫生

Objective To investigate the awareness of the Radiation Shielding Requirements for Radiotherapy Room–Part 2: Radiotherapy Room of Electron Linear Accelerators (GBZ/T 201.2—2011) among relevant practitioners in medical institutions as well as its implementation and application situation and collect relevant problems and suggestions for an evaluation of the scientificalness, standardization, and timeliness of the standard, and to provide a scientific basis for the further revision and implementation of the standard. Methods An online questionnaire survey was conducted among relevant employees in medical institutions providing medical linear accelerator radiotherapy across 22 provinces of China, which investigated the awareness, training, application, and revision suggestions related to GBZ/T 201.2—2011. The questionnaires were collected and analyzed. Results A total of 340 relevant practitioners filled out the questionnaire. Of the participants, 66.80% were physicists; 79.11% had an awareness of the standard; 56.18% ever participated in the standard-related training; but the survey results showed that the practitioners did not have a good knowledge of the standard’s content, and the training and promotion were not enough; 83.24% thought that the standard had been widely used; 17.60% thought that the standard needed to be revised; 76.76% thought that there was a need to add calculation examples; 88.82% thought that neutron shielding needed to be considered for the 10 MV X-ray accelerator room. Conclusion The standard has been widely known in the field of radiotherapy protection. With the development of radiotherapy technology, the standard should be revised to add calculation examples and consider neutron shielding in the 10 MV X-ray accelerator room. The standard is highly technical and difficult to grasp, so the promotion and implementation goals should be appropriate for different personnel groups, the training for employees at key posts should be strengthened, and the methods recommended in the standard should be uniformly used throughout the country.

Rapid identification of phthalides and organic acids in Angelica sinensis based on UPLC-Q-TOF/MS / 中国药房

OBJECTIVE To establish a comprehensive and rapid m ethod for the a nalysis of chemical constituents as phthalides and organic acids in Angelica sinensis ，and to provide scientific reference for the quality evaluation and pharmacodynamic substance research of A. sinensis . METHODS The 70％ ethanol extract of A. sinensis was analyzed by ultra high performance liquid chromatography-quadrupole-time of flight tandem mass spectrometry （UPLC-Q-TOF/MS）. The determination was performed on ACQUITY UPLC BEH-C 18 column with mobile phase consisted of 0.1％ formic acid solution- acetonitrile（gradient elution ）at the flow rate of 0.3 mL/min. The column temperature was set at 30 ℃，and sample size was 2 µL. The ion source was an electrospray ion source ，using positive ion scanning mode ，and the mass scanning range was m/z 50-1 000. Capillary voltage was 4 000 V； atomizer pressure was 35 psi；cracking voltage was 135 V and the taper hole voltage was 65 V；the temperature of dry gas was 320 ℃；the flow of dry gas was 10 L/min and the flow of sheath gas was 11 L/min；collision energy were 20 and 40 V. Qualitative Analysis 10.0 software was used to obtain the retention time of compounds ，the accurate mass number of excimer ion peaks and secondary fragments. The compounds were analyzed by comparing with the mass spectra of the reference substance ，combined with relevant literature ，mass spectrometry cleavage law and database such as Chemspider ，MassBank，PubChem. RESULTS A total of 72 compounds were identified or deduced from A. sinensis ，including 55 phthalides，13 organic acids and 4 other constituents. CONCLUSIONS The established method is rapid and accurate for the identification of chemical constituents from A. sinensis ，such as organic acids and phthalides ，which provides an efficient and rapid analytical method for the comprehensive characterization of its chemical constituents.

Monitoring and analysis of activity concentrations of 7Be and 210Pb in atmospheric aerosol in Beijing from 2017 to 2020 / 中华放射医学与防护杂志

Objective:To monitor and analyze the activity concentrations of 7Be and 210Pb in atmospheric aerosol in Beijing from 2017 to 2020. Methods:Totally 1 074 atmospheric aerosol samples were collected by high flow air sampler (SnowWhite) including 275 in spring, 266 in summer, 262 in autumn and 271 in winter and subjected to analysis by low background high-purity germanium gamma-ray spectrometery (ORTEC) to determine the activity concentrations of 7Be and 210Pb. Results:The activity concentrations of 7Be in atmospheric aerosol were from 0.56 to 14.84 mBq/m 3, with an avearage of 6.84 mBq/m 3, and from 0.01 to 9.37 mBq/m 3 for 210Pb, with an avearage 3.19 mBq/m 3. The differences in activity concentrations of 7Be and 210Pb in atmospheric aerosol among differernt seasons were statistically significant ( F=32.66, 93.93, P<0.05). Activity concentration of 7Be was highest in spring, followed by autumn, and lowest in summer and winter. Activity concentration of 210Pb ranged from winter, autumn, spring to summer in descending order. Conclusions:The activity concentrations of 7Be and 210Pb in atmospheric aerosol in Beijing from 2017 to 2020 fluctated within the range of normal level.

Output dose investigation and analysis of external beam radiotherapy in Beijing / 中国辐射卫生

Objective@#To study the output dose of external beam radiotherapy in Beijing and analyze the cause of output dose  deviation.  Guidance  is  given  on  the  selection  of  measurement  methods,  calculation  formulas  and  parameters.@*Methods@#During 2020, the output doses of medical electron accelerators, tomotherapy, cyberknife, and γ-knife were meas- ured based on the water absorbed dose calibration factor combined with the requirements in the IAEA TRS398 and TRS483 reports, and low-energy X-rays were measured based on the air kerma calibration factor combined with the requirements in the AAPM protocal. The output dose was measured and compared with the preset irradiation value.@*Results　@#A total of 59 external beam radiation therapy equipments’s output dose were investigated.2 of the 49 accelerators’s absolute value of relative deviation between the system indication value and the measurement exceeded 3%; the deviation of other external beam radiotherapy equipments was less than 3%.@*Conclusion　@#A unified method and multi-party quality control can ensure the accuracy of the output dose. In the routine operation of the equipment, the hospital should strictly implement periodic inspections to ensure accurate and reliable radiotherapy.

Study on dosimetric and radiation safety performance parameters of helical tomotherapy unit / 中华放射医学与防护杂志

Objective To understand the functional status and radiation protection requirements of helical tomotherapy (TOMO) unit when it is applied in clinic treatment so as to promote the construction of TOMO quality control system.Methods A helical tomotherapy unit with a type of tomotherapy Hi-Art was employed as the radiotherapy unit.A series of tests and analyses on dosimetric and radiation safety performance parameters of the TOMO unit were conducted with the use of a A1SL ionization chamber,a set of solid water equivalent phantoms and other test equipments.The performance parameters were compared with that of a conventional 6 MV accelerator with a type of ARTISTE.Results The deviations of static and dynamic output dose were-1.51％ and 1.18％,respectively.The values of PDD10/PDD1.5 and PDD20/PDD1.5 were 0.608 and 0.318 within the range of X-ray quality parameters calibration.Under the different field conditions of 40 cm × 5 cm,40 cm × 2.5 cm and 40 cm × 1 cm,the stability of transverse/longitudinal dose distribution curve was no more than 1.20％ and the offset distance of Jaw width was smaller than 0.5 mm.Radiation leakage ratio of the treatment rotating center from the muhileaf collimator (MLC) was 0.20％.No matter the average or the maximum value of the leakage radiation from couch plane was less than 0.02％.Conclusions The performances and testing requirements of TOMO unit are different from a conventional electron linear accelerator,the quality control index of TOMO unit should be set seperately and tested strictly in terms of the specific requirements of the unit by complying with the QC programme.The reliable quality control system should be established and effectively implemented to serve the radiotherapy quality and radiation safety effectively in the tomotherapy.

Investigation and analysis of patient dose levels from diagnostic radiology in Beijing / 中华放射医学与防护杂志

Objective To investigate the radiation dose levels to the adults examined from diagnostic exposure in Beijing. Methods The radiation doses to the examined individuals were measured by using individual diagnostic radiology equipments in 30 random hospitals from a total of 10 districts and suburban areas, including 1 182 samples of X-ray photography,542 samples of mammography and 410 samples of CT examination. Results 2 134 samples were measured in this study. The dose ranges of X-ray photography, CR, and DR were 0?4 -24?1, 0?3 -13?9 and 0?1 -15?9 mGy, respectively. The average dose range of glandular breast was 0?3-5?4 mGy. In 410 CT samples the value of CTDIw , CTDIvol and DLP were 28?1 - 96?3 mGy, 7?0 - 23?4 mGy, and 162?2 - 898?1 mGy·cm, respectively. Conclusions Several dose levels from diagnostic examination were higher than guidance level for medical exposure in GB 18871-2002,which should be noted.

Construction of conditionally replicative adenovirus vector carrying TRAIL gene and its mRNA and protein expressions induced by ionizing radiation / 吉林大学学报(医学版)

Objective To construct the conditionally replicative adenovirus vector pAd-Egr1-TRAIL-hTERT-E1A-E1Bp-E1B55K carrying early growth response gene-1 (Egr1)promoter and tumor necrosis factor related apoptosis inducing ligand (TRAIL)gene, and to observe the effects of the vector combined with 2 Gy irradiation on the TRAIL expression in MDA-MB-231 cells.Methods Egr-1 promotor sequence was cloned from pMD18 T-Egr1, TRAIL was constructed the downstream of Egr1 promoter, pShuttle-Egr1-TRAIL-hTERT-E1A-E1Bp-E1B55K (CRAd.pEgr1-TRAIL)was constructed,after the adenovirus vector was packaged successfully,MDA-MB-231 cells were infected with them and irradiated with X-rays.Real time PCR method and ELISA were used to detect the expression levels of TRAIL mRNA and protein, respectively. Six groups in the experiment were set up:control, 2 Gy,CRAd.p,CRAd.pEgr1-TRAIL,CRAd.p + 2 Gy and CRAd.pEgr1-TRAIL + 2 Gy. Results The recombinant adenovirus vector pAd-Egr1-TRAIL-hTERT-E1A-E1Bp-E1B55K was constructed and packaged successfully.The expression level of TRAIL mRNA in MDA-MB-231 cells transfected with the vector of 5 MOI for 24 h following 2.0 Gy X-rays irradiation began to increase and arrived to the top 8 h later in various groups,then declined.The expression level of TRAIL protein in MDA-MB-231 cells began to increase 6 h after irradiation and reached to the peak 24 h later,then declined 48 h later.There were significant differences in the expression levels of TRAIL protein between CRAd.pEgr1-TRAIL + 2.0 Gy and other groups at the same time point (P<0.01). Conclusion The recombinant adenovirus vector is obtained successfully, and the TRAIL mRNA and protein expression levels in MDA-MB-231 cells can be increased significantly by the vector combined with 2.0 Gy X-rays irradiation.

An Experimental Study on the Release of Endotoxin from A. Baumannii Induced by Antibiotics Biapenem,Meropenem and Levofloxacin / 天津医药

Objective To study mechanisms of lipopolysaccharide (LPS) release from Acinetobacter baumannii (A. baumannii) induced by biapenem (BIPM), meropenem (MEM) and levofloxacin (LVFX). Methods A. baumannii was ex-posed to different concentrations of BIPM, MEM, LVFX, and ceftazidime (CAZ) at different time points. The LPS release was measured by tachypleus amebocyte lysate (TAL) test. Quantities of bacteria exposing to 0.5 MIC antibiotics were measured. The morphology of bacteria treated with different antibiotics for 7-hour was evaluated by light microscope. Results The LPS releases of A. baumannii treated with four kinds of antibiotics were significantly less than those of control group. In the later period, LPS releases of A. baumannii exposed to the high concentration of antibiotics tended to smooth. The cell quanti-ties of bacteria were significantly lower in treatment group than that of control group. The cells of A. baumannii treated with CAZ and LVFX showed long filamentous shape. The bacteria exposed to MEM and BIPM showed obviously globular. At the same time, some bacterial cells were induced to lysis rapidly by BIPM. Conclusion The level of LPS release is influenced by kinds of antibiotics, concentration and incubation period. All kinds of antibiotics could induce morphological changes of A. baumannii, which may be related to the different mechanisms that bacteria induce the different levels of LPS release.

Biological characteristics of artificial bones / 吉林大学学报(医学版)

Objective To synthesize a novel polymer POMs-CS/nano-HAP and study its biocompatibility and safety.Methods The biocompatibility was evaluated through the experiments including acute systemic toxicity test,pyrogen,intracutaneous test.Results The crystals of POMs-CS/nano-HAP were equal on sizes, which average diameter was 20 nm and length was 100 nm.By comparing,the polymer were better than those reported,which were closer to the natural bone.The material had no toxicity,no irritation to skin.(Conclusion The) POMs-CS/nano-HAP artificial bone possesses excellent biocompatibility.

Inhibitory effects of novel heteropoly compounds on influnenza virus (H1N1) in vitro / 吉林大学学报(医学版)

Objective To investigate the toxicities and inhibitory effects of three kinds of kegin-type novel heteropoly compounds which were synthesised by molecular assembly interactions on influnenza A virus(H1N1) in vitro.Methods The toxicities and anti-influnenza virus activities were tested by methods of CPE-MTT and chick embryos culture.Results TC_(50) in MDCK cells and LD_(50) in chick embryos of three kinds of kegin-type novel heteropoly compounds were higher than those of amantadine.TI in MDCK cells and chick embryos were both higher than that of amantadine. Conclusion The three kinds of kegin-type novel heteropoly compounds have lower toxicities and higher anti-virus effects on influnenza A virus(H1N1) than amantadine.Through chemic modifications,the toxicity of amantadine can be decreased and the activity of amantadine can be increased.

FRNK inhibited hepatic stellate cells in vitro / 基础医学与临床

Objective To investigate the effect and mechanism of FRNK on the proliferation of Hepatic Stellate Cells in vitro.Methods FRNK plasmid mediated by cationic liposome was transfected into HSCs.The proliferation of HSCs was evaluated by modified MTT assay.The level of FRNK,FAK,p-FAK(Tyr397),ERK1 and p-ERK in HSCs were assayed by Western blot and RT-PCR.Results Compared with nFRNK plasmid group,FRNK inhibited the proliferation of HSCs and the inhibition rates at 12,24 and 48 h were 20.07%,26.16% and 29.77%(P

Apoptosis related with extracellular adenosine triphosphate and adenosine and their purinergic receptors / 中国药理学通报

Extracellular adenosine triphosphate (ATP) and adenosine are important signaling molecules in both intracellular and extracellular microenviroments of cells. They exert cytoxic and apoptotic effects in some tissues such as tumor. The proapoptotic mechanisms of adenosine and its receptors are involved in Adenylyl cyclase(AC), cAMP, Ca 2+ , etc. Apoptosis induced by ATP is as sociated with several purinergic receptors including P2X_1, P2X_2, P2X_7, P2Y_1, P2Y_2, et al, it is also involved in FasL/FasR, T cell receptor(TCR), and gene regulations of bcl-2 and bax.