Analysis of radionuclide content in the surface soil of Panjin, China / 中国辐射卫生

@#<b>Objective</b> To measure the specificactivity of natural and synthetic radionuclides in the environmental soil of Panjin, China and determine the content of radionuclides in the surface soil, and to conduct a scientific assessment of the radiation health risks of residents in this area. <b>Methods</b> Thirty-one surface soil samples were collected within the jurisdiction of Panjin, and a high-purity germanium detector was used for γ spectrum analysis to obtain the content of radionuclides and the current environmental radioactivity level. The two independent samples mean <i>t</i>-test was used to compare the specific activity data of radionuclides in soil samples between Panjin and Liaoning Province or China. <b>Results</b> The meanspecific activities of natural radionuclides ²³⁸U, ²²⁶Ra, ²³²Th, ⁴⁰K, and synthetic radionuclide ¹³⁷Cs in the surface soil samples of Panjin were 18.7 Bq/kg, 19.6 Bq/kg, 23.5 Bq/kg, 604.6 Bq/kg, and 0.9 Bq/kg, respectively. <b>Conclusion</b> The specific activities of natural and synthetic radionuclides in the surface soil samples of Panjin Area at the background level, causing a very low health risk to the people in this area.

Analysis of guidance levels of radionuclide for food and drinking water / 中国医学装备

Objective:To investigate guidance levels of radionuclide for food and drinking water.Methods: According to the relevant standards and technical documents issued by international organizations, the computing methods of guidance levels of radionuclide for food and drinking water under the existing exposure situation and emergency exposure situation were analyzed and researched.Results: The calculated guidance levels of 17 radionuclides in drinking water and 20 radionuclides in food in existing exposure situation were provided, and the guidance levels of 24 radionuclides in food and drinking water in emergency exposure situation also were proposed. It was found that the relevant standards in China were lag and the standard of guidance levels of radionuclides activity concentrations for drinking water were deficient.Conclusion: It is suggested that the standards of guidance levels of radionuclide for food and drinking water in China should be formulated or revised by referring to international standard that issued from international organization and taking into account the specific conditions in China so as to preferably protect public health of our country.

A highly active GH11 xylanase from Penicillium sp. L1 with potential applications in xylo-oligosaccharide production / 生物工程学报

Xylanase is a high-profile glycoside hydrolase with applications in brewing, feed, pharmacy and bioenergy industries, but most of xylanases are in active below 30 ℃. In order to obtain low temperature active xylanase, a xylanase gene, XYN11A, was cloned from Penicillium sp. L1 and expressed in Pichia pastoris GS115. After purification and enzyme assay, optimal pH and temperature were determined to be 3.5 to 4.0 and 55 ℃. This enzyme was stable at acid and neutral condition (pH 1.0 to 7.0) or under the treatment of 40 ℃ for 1 hour. This xylanase displayed strong resistance to all tested ions and chemicals. Noteworthily, XYN11A maintained a higher activity of 6 700 U/mg than a lot of GH11 xylanase, and demonstrated higher activity (24% to 58%) at lower temperature from 20 to 40 ℃. After beechwood xylan hydrolysis for 16 h, the hydrolysates consisted mainly of xylobiose, xylotriose and xylotetraose and barely of xylose, thus XYN11A could be used for the production of prebiotic xylooligosaccharide. Possessing the features of acidophilic, highly active at lower temperature and oligosaccharide production, XYN11A demonstrated great potential in food and feed industrials.

Test and analysis of radioactivity levels in main agricultural production around a uranium mine in Northern Guangxi / 中华放射医学与防护杂志

Objective To investigate radioactivity levels in the main agriculture products around a uranium mine in Northern Guangxi.Methods The agriculture products and soil samples were collected and analyzed by using HPGe gamma ray spectrometer.Results The specific activity of 226Ra in radish (including leaf),radish leaves and radish,collected in one place,were 45.0,66.7 and 32.3 Bq/kg,respectively.Those of 226Ra and 23SU in the radish soil collected in the same place were 19 672 and 85 917 Bq/kg,respectively.The transfer coefficients of soil-to-radish and soil-to-leaves were 1.61 × 10-3 and 3.40 × 10-3,consistent with those reported in relevant literature.Radioactivity levels in agricultural products in another survey was in consistence with those in the national survey for food products.Radioactivity levels in soil elsewhere near the radish site was consistent with the results of the national soil radioactivive background survey.Conclusions The soil in this place has been contaminated by the nearby uranium mine.It is important to investigate this place further and take the necessary measures.

Quality control of human ASPP2 recombinant adenovirus / 中国药理学通报

Aim Toanalyzethekeyqualityandestablishmeth-ods for essential quality control of human recombinant ASPP2 adenovirus.Methods TheviralstructuralgeneofE2Bandtar-get gene of ASPP2 were identified by PCR;The number of virus particles was measured by UV-SDS methods;Infectious titer was determined by TCID50 assay;Target protein of ASPP2 was ob-served by Western blot assay;The biological effects of recombi-nant adenovirus on liver cancer cells were evaluated by MTT as-say;A549 cells were used to check replication of the competent adenovirus(RCA)by the observation of the cytopathic effect. Results PCRanalysisofE2BandASPP2wasinconsistent with theoretical values;Particle numbers of virus were 5. 6 × 1012 VP/mL,infectious titer was 2 ×1011 IU/mL and specific activity was 3. 5%;ASPP2 protein expression could be detected when cells were infected with virus for 24 h;Growth inhibition of liver cancer cells could be found by adding recombinant ASPP 2 adenovirus;The level of RCA was less than 1 RCA/3. 0 ×1010 VP,in line with the standards of China Food and Drug Adminis-tration(SFDA).Conclusion Thequalitycontrolmethodswere established aiming at key characters of human recombinant AS-PP2 adenovirus,which may provide foundations for its quality standard and future applications.

Separation and screening of components with fibrinolytic enzyme activity from twelve Chinese herbal medicines / 国际中医中药杂志

Objective To separate and screen components with fibrinolytic enzyme activity from twelve Chinese herbal medicines. Methods The components were extracted with water and precipitated with salt, and they were tested by fibrinolytic protein plates method. The active components with fibrinolytic activity were separated and screened which were compared with urokinase. Results Eleven of the twelve extracts showed fibrinolytic activity, while Trichosanthes kirilowii got the biggest fibrinolytic zone after 36 hours, followed by Alisma plantago-aquatica and Leonurus japonicus, and the Radix Astagali got the smallest one. According to the concentration of the protein, the area of the fibrinolytic zone and the specific activity of the components, the extract from Angelica sinensis exhibited the best specific activity at level of 48.46U/mg. Conclusion The extracts from Chinese herbal medicines except Semen Persicae exhibit fibrinolytic enzyme activity which can dissolve the fibrin in different degrees.

Expression of manganese superoxide dismutase in rat blood, heart and brain during induced systemic hypoxia.

Background: Hypoxia results in an increased generation of ROS. Until now, little is known about the role of MnSOD - a major endogenous antioxidant enzyme - on the cell adaptation response against hypoxia. The aim of this study was to determine the MnSOD mRNA expression and levels of specific activity in blood, heart and brain of rats during induced systemic hypoxia. Methods: Twenty-five male Sprague Dawley rats were subjected to systemic hypoxia in an hypoxic chamber (at 8-10% O2) for 0, 1, 7, 14 and 21 days, respectively. The mRNA relative expression of MnSOD was analyzed using Real Time RT-PCR. MnSOD specific activity was determined using xanthine oxidase inhibition assay. Results: The MnSOD mRNA relative expression in rat blood and heart was decreased during early induced systemic hypoxia (day 1) and increased as hypoxia continued, whereas the mRNA expression in brain was increased since day 1 and reached its maximum level at day 7. The result of MnSOD specific activity during early systemic hypoxia was similar to the mRNA expression. Under very late hypoxic condition (day 21), MnSOD specific activity in blood, heart and brain was significantly decreased. We demonstrate a positive correlation between MnSOD mRNA expression and specific activity in these 3 tissues during day 0-14 of induced systemic hypoxia. Furthermore, mRNA expression and specific activity levels in heart strongly correlate with those in blood. Conclusion: The MnSOD expression at early and late phases of induced systemic hypoxia is distinctly regulated. The MnSOD expression in brain differs from that in blood and heart revealing that brain tissue can possibly survive better from induced systemic hypoxia than heart and blood. The determination of MnSOD expression in blood can be used to describe its expression in heart under systemic hypoxic condition.

The development and application of a quantitative ELISA detection method for enterovirus 71 antigen / 中华微生物学和免疫学杂志

ObjectiveTo develop an ELISA method for quantitative determination of enterovirus 71 (EV71) antigen.The method can be applied to detect EV71 antigen contents and analyze the correlation between immunogenicity and immunoprotection.It also can be used for tissue culture infective dose( TCID50 ) assay.MethodsA double antibody sandwich ELISA method was developed for quantitative determination of EV71 antigen on the basis of the high-affinity neutralizing monoclonal antibodies ( K8G2 and Y8H2-HRP).This method was compared with microscopic observation for the detection of EV71 TCID50.The correlation was analyzed between the specific activity of EV71 antigen and the EV71 neutralizing antibody titer in immune serum.ResultsThe linear range of this method was 0.125-4.0 U/ml and the R2 value was 0.9911.The reagent did not react with other antigens except EV71 antigen.The recovery ratio of this method was 0.89-1.16.The coefficient of variation was less than 15％.The heat recovery rate was above 85％ when the reagent was in 37℃ for 9 days.There was a good correlation in TCID50 of EV71 between this method and microscopic observation,r=0.990.The specific activity of EV71 antigen had positive correlation with the neutralization titer of immune serum in 21 EV71 strains,r=0.930.ConclusionThe quantitative ELISA method for EV71 antigen was developed,which could be used to detect EV71 antigen contents and analyze TCID50.The specific activity of EV71 antigen detected by the method could be used to evaluate the immunoprotection of the vaccine potency test.

Experimental research on specific activity of 24Na using Chinese reference man phantom irradiated by 252Cf neutrons source / 中华放射医学与防护杂志

Objective To investigate the specific activity of 24Na per unit neutron fluence,AB/Φ,in blood produced for Chinese reference man irratiaded by 252Cf neutron source,and to analyze the effects of scattering neutrons from ground,wall,and ceiling in irradiation site on it.MethodsA 252Cf neutron source of 3 × 108 n/s and the anthropomorphic phantom were used for experiments.The phantom was made from 4 mm thick of outer covering by perspex and the liquid tissue-equivalent substitute in it.The data of phantom dimensions fit into Chinese reference man.The weight ratios of H,N,O and C in substitute equal from source to long axis of phantom were 1.1,2.1,3.1 and 4.1 m,respectively.Both the neutron source and the position of xiphisternum of the phantom were 1.6 m above the floor.ResultsThe average specific activity of 24Na per unit neutron fluence was related to the irradiation-distances,d,and its The AB/ΦM corresponds to that of phantom irradiated by plane-parallel beams,and the value is about more 3% than that by BOMAB phantom reported in literature.It has shown that floor-( wall-)scattered neutrons in irradiation site have significant contribution to the specific activity of 24Na ,but they contributed relatively little to the induced neutron doses.Consequently,using the specific activity of 24 Na for assessing accidental neutron doses received by an individual,the contribution of scattered neutrons in accident site will lead dose to be overestimated,and need to be correct.

Improved purification process of β- and α-trypsin isoforms by ion-exchange chromatography

The purpose of this work was to improve the separation and yield of pure β- and α-trypsin isoforms by ion-exchange chromatography and to characterize some physical-chemical properties of these isoforms. Purification of trypsin isoforms was performed by ion-exchange chromatography in 0.1 mol/L tris-HC buffer, pH 7.10 at 4ºC. The sample loading, salt concentration, flow rate and pH of mobile phase were varied to determine their effects on the resolution of the separation. The resolution was optimized mainly between β- and α-trypsin. Pure isoforms were obtained by chromatographying 100 mg of commercial trypsin during seven days, yielding 51 mg of high purity β-trypsin and 13 mg of α-trypsin partially pure, with small amounts of contaminating of ψ-trypsin. Thus, time and resolution of purification were optimized yielding large amounts of pure active enzymes that are useful for several research areas and biotechnology.

O propósito deste trabalho foi melhorar a separação e o rendimento das isoformas puras β- e α-tripsina por meio de cromatografia de troca iônica e caracterizar algumas propriedades físico-químicas dessas isoformas. A purificação de isoformas de tripsina foi realizada em SE Sephadex, com tampão tris-HCl, pH 7,10 a 4ºC. A quantidade de amostra, a concentração salina, o fluxo e o pH da fase móvel foram variados para determinar o efeito sobre a resolução da separação. A resolução foi otimizada principalmente entre β- e α-tripsina, utilizando o pH 7,10 a 4ºC. Isoformas puras foram obtidas a partir de 100 mg de tripsina comercial bovina depois de sete dias de cromatografia, fornecendo 51,0 mg de β-tripsina totalmente pura e 13,0 mg de α-tripsina parcialmente pura, com quantidades pequenas de contaminação por ψ-Tripsina. Assim, tempo e resolução da purificação foram otimizados redendo grandes quantidades de enzimas puras e ativas que são úteis em várias áreas de pesquisa e ciências biotecnológicas.

Synthesis of a Dopamine Transporter Imaging Agent, N-(3-18Ffluoropropyl)-2 -carbomethoxy-3 -(4-iodophenyl)nortropane / 대한핵의학회잡지

PURPOSE: N-(3-[18F]Fluoroporpy)-2beta- carbomethoxy-3beta-(4-iodophenyl) nortropane ([18F]FP-CIT) has been shown to be very useful for imaging the dopamine transporter. However, synthesis of this radiotracer is some what troublesome. In this study, we used a new method for the preparation of [18F]FP-CIT to increase radiochemical yield and effective specific activity. MATERIALS AND METHODS: [18F]FP-CIT was prepared by N-alkylation of nor-beta-CIT (2 mg) with 3-bromo-l-[18F]fluoropropane in the presence of Et3N (5-6 drops of DMF/CH3CN, 140 degree C, 20 min). 3-Bromo-l-[18F]fluoropropane was synthesized from 5 microliter of 3-bromo-l-trifluoromethanesulfonyloxypropane (3-bromopropyl -l-triflate) and nBu4N18F at 80 degree C. The final compound was purified by reverse phase HPLC and formulated in 13% ethanol in saline. RESULTS: 3-Bromo-l-[18F]fluoropropane was obtained from 3-bromopropyl-l-triflate and nBu4N18F in 77-80% yield. N-Alkylation of nor-beta-CIT with 3-bromo-l-[18F]fluoropropane was carried out at 140 degree C using acetonitrile containing a small volume of DMF as the solvents. The overall yield of [18F]FP-CIT was 5-10% (decay-corrected) with a radiochemical purity higher than 99% and effective specific activity higher than the one reported in the literature based on their HPLC data. The final [18F]FP-CIT solution had the optimal pH (7.0) and it was pyrogen-free. CONCLUSION:: In this study, 3-bromopropyl-l-triflate was used as the precursor for the [18F]fluorination reaction and new conditions were developed for purification of [18F]FP-CIT by HPLC. We established this new method for the preparation of [18F]FP-CIT, which gave high effective specific activity and relatively good yield.

ANTIGEN SPECIFIC ACTIVITIES OF THE TRANSFER FACTOR AGAINST HERPES SIMPLEX VIRUS TYPE I / 中国免疫学杂志

TF was prepared from spleen cellsof both HSV-1-immunized mice(TF_(HSV)-1)and control group animals(TFn)4 weeks after immunization.The leukocyte adherence inhibitionindex(LAII)demonstrating the spe-cific activity of TF_(HSV)-1 in vitrowas found to be significantly higherthan that of control(P