The release of ^14C—chlorsulfuron bound residue by autoclaving method and its identification

When individual microorganisms were used to release bound pesticide resdues,it was ussually not take into full account whether the autoclaving method could lead to the release of bound residues.The soil containing bound ^14C-chlorsulfuron residues was treated with an autoclave in this study.The results reveal that the bound ^14C-chlorsulfuron residue can be released from the soil when treated with the autoclave and the release rate can be remarkably enhanced by adding water into the soil when subjected to such treatment.A TLC analysis showed that the released ^14C-residue was one of the degraded products of ^14C-chlorsulfuron.After derivatization and analysis using the GC-MS,the released ^14C-residue was tentatively identified as 2-amnino-4-hydroxyl-6-methyl-1,3,5-triazine.     

STUDY ON BEHAVIOUR OF CR FORMULATION OF THIOBENCARB IN A MODEL PADDY FIELD

The fate of CR formulation of ^14C-thiobencarb (thio.)was studied at the high rate of application in a model paddy field.Thio.could be released from the alginate formulation (TAL-17189) into water.The concentration of thio.in water increased with time,then declined.Thio.in water could be converted to more than 12^14C-degradation products which changed with time.An unknown degradation product(Mo) was always prevailing after application.Thio.in water could be adsorbed by soil particles.Most of the adsorbed thio.retained in upper layer.Thio.in soil could be also degraded to more than 6 products.Thio.and its degradation products could conjugate with the compositions of soil to bound residues(BR),Thio.was 45.6% of the total 14C-extractable residues(ER) in upper layer soil at harvest,14C-thio.in water and soil could be uptaken by rice plants.Thio.In plants existed in ER and BR.Most of ^14C-residues in straw,roots,brown rice and husk were in bound form,more than 92% of the total ^14C in them at harvest respectively,Thio.in plants could be metabolzed to more than 9 metabolites which changed with time.^14C-thio.in straw brown rice and husk accounted for 55.88,6.06 and 11.18% of the total ^14C-ER of them at harvest respectively.An unknown ^14C-metabolite in brown rice was prevailing accounted for 63.03% of the total ^14C-ER.     

DETERMINATION OF WHOLE—BODY PROTEIN IN SMALL LIVE ANIMALS BY IVNAA

Measurement of nitrogen in small live animals (Weighing about 3 kg) can be used to determine the whole- body protein in the animals. Nitrogen may be measured by IVNAA in which the capture gamma rays of neutron induced are detected and counted. The neutron flux is provided by a collimated 740 GBq (20Ci) Pu- Be source. The 10.83 MeV thermal neutron capture gamma rays from ~(14)N are detected by a 12.7 cm by 10.2 NaI (T1) detector. The nitrogen of a live rabbit was measured and recorded each day for a period of two months. The statistical error and reproducibility of measurement were around 10%. For a 1000 s irradiation the dose equivalent was 300μ Sv.     

Biodistribution and pharmacokinetics of ^99mTc—CQDO and ^99mTc—CQDO—MeB for new myocardial imaging agent

A comparison of ~(99m)Tc- CQDO and ~(99m)Tc-CQDO-MeB has been made for biodistribution and pharmacokinetics. ~(99m)Tc-CQDO and its adducts of methaneboronic acid ~(99m)Tc-CQDO-MeB were prepared by the reduction of Na~(99m)TcO_4 with SnCl_2·2H_2O in aqueous solution. Radiochemical purity of ~(99m)Tc-CQDO and ~(99m)Tc-CQDO-MeB determined by TLC were over 95% after extraction. Biodistributions of ~(99m)Tc-CQDO and ~(99m)Tc-CQDO-MeB in mice demonstrated that both of them could be easily absorbed by myocardium, and the peak uptake of each were 10.83±2.2% ID/g and 11.84±1.69%ID/g, respectively. ~(99m)Tc-CQDO showed rapid clearance from myocardial tissue while ~(99m)Tc-CQDO-MeB had long retention in heart muscle. The myocardial uptake of ~(99m)Tc-CQDO was only 5.88±1.66%ID/g at 10 min. and the uptake of ~(99m)Tc-CQDO-MeB was 7.42±0.17%ID/g at 60 min. The elimination of each from blood has a biexponential pattern, the first T_(1/2) is 1.38 and 1.5 min, respectively. The partition coefficient of ~(99m)Tc-CQD     

THEORETICAL DESCRIPTION OF PERCENTAGE DEPTH DOSE CURVE FORγ—RAY OF ~(60)Co

A formula describing the percentage depth dose curve for ~(60)Co γ beams is theoretically developed. The formula only needs a few data determined by measuring directly in water phantom and can be used to calculate the whole set of percentage depth dose (PDD) and tissuse air ratios (TAR) for the wide range of SSD (from 20cm to 100cm), field size (from 4cm×4cm to 20cm×20cm) and depth (from d_m to 30cm). The data calculated by the formula fits very well to the data currently used in clinics with the maximum error less than 1% and probable error of about 0.1%-0.3%. Using this formula can overcome the time-exhausting work in measurement of PDD and TAR.     

THE FATE OF ~(14)C-FENITROTHION IN RICE-FISH MODEL ECOSYSTEM

The fate of fenitrothion in rice- fish ecosystem was studied using C- fenitrothion (14C- F) labelled at methoxyl and two application rates. The fenitrothion in water disappeared quickly, only 8 and 11 ppb in two treatments at harvest were detected respectively. Most of 14C-F in soil existed in upper layer and that in plants appeared in shoots. The extractable residues in cargo rice were 0.36 and 0.58 ppm in two treatments respectively. 14C- residues (14C- R) were concentrated in bones, next viscera, meat and scales. Total 14C-R in meat were 0.92 and 1.77 ppm at harvest. Comparing two treatments, the residue dynamics of fenitrothion in water, soil, plants and fish were similar. 14C- R in water and soil after harvest affected the rice- fish ecosystem in the next season. However, the extractable 14C- R in cargo rice, soil and water were very low. Fenitrothion 14C- fenitrothion Rice- fish Model ecosystem     

SYNTHESIS OF THE RING—AND SIDE—CHAIN—~(14)C—LABELED 1,2—BIS—(4—MORPHOLINOMETHYL—3,5—DIOXOPIPERAZIN—1—YL) PROPANE

The ring-and side-chain-~(14)C-labeled probimane, 1,2-bis (4-morpholinomethy1-3,5-dioxopiperazin-1-yl) propane were synthesized from acetic acid-1-~(14)C in 4 steps and from ~(14)C-formaldehyde in 1 step respectively. The radiochemical yeild for the ring labeling was 28.1%; for the side-chain labeling was 18.5%.     

Radiation induced decontamination of Cr(Ⅵ), Cu(Ⅱ) and phenol in some tannery effluents

Industrialization has led to a number of environmental problems, such as release of toxic metals and other toxic organic and inorganic compounds to the environment. Among all, the rapid expansion of leather related industries in Pakistan have resulted in considerable environmental problems and effluents from processing of both domestic and imported hides and skins have increased pollution to alarming levels. Some tannery effluents of Peshawar area investigated in the present study showed high concentrations of Cr(Ⅵ) (2.7-12.6 mg/L), Cu(Ⅱ) (2.6-11.4 mg/L) and phenol (0.1-4.2 mg/L). These contaminants are very toxic and must be removed from effluents before releasing into water bodies. A new technique of gamma irradiation has been investigated to decrease the load of COD and concentrations of Cr(Ⅵ), Cu(Ⅱ) and phenol associated with tannery effluents to the permitted values. It was observed that concentration of Cr(Ⅵ) in the effluents can be brought to the permitted level by applying radiation dose of 3 kGy. A radiation dose of 2.5 kGy was required to remove more than 95% of Cu(Ⅱ) and 100 % degradation of phenol in tannery effluents could be achieved by only one kGy of radiation dose.     

Cross Section Measurement of ~(64)Zn(n,p)~(64)Cu Reaction from 4 to 7 MeV

Introduction In the areas of activation and neutron scattering cross sections, there are still deficiencies in the nuclear database. Activation cross sections were found to be unsatisfactory in 83 of the 183 reactions reviewed. The excitation curve for ~(64)Zn(n,p)~(64)Cu reaction has been measured from threshold to 10 MeV by different authors. All of these measured cross sections are not in very good agreement with each other. To clarify the discrepancy it is necessary to measure the cross sections for ~(64)Zn(n,p)~(64)Cu reaction once again.     

Extraction chromatography–electrodeposition(EC–ED) process to recover palladium from high-level liquid waste

The extraction chromatography–electrodeposition(EC–ED) process was proposed for the quantitative recovery of palladium from high-level liquid waste(HLLW) in this study. The process coupled the extraction chromatography method to obtain the decontamination of Pd(II) from HLLW with the electrochemical method to recover metallic palladium from the concentrated solution.Separation of Pd(II) from a nitric acid medium by extraction chromatography using iso Bu-BTP/SiO_2-P adsorbent and the electrochemical behavior of Pd(II) in nitric acid solution in the presence of thiourea(TU) were investigated.iso Bu-BTP/SiO_2-P exhibited a high selectivity for Pd(II)over other fission products(FPs), and Pd(II) could be desorbed by TU from loaded BTP/SiO_2-P. The adsorbent performed good stability against HNO_3 because the adsorption performance kept Pd(II) after extended contact with HNO_3 solution. The column experiment achieved the separation of Pd(II) from simulated HLLW successfully.The electrochemical behavior of Pd(II) in palladium desorption solution containing TU and nitric acid was investigated at a platinum electrode by cyclic voltammetry. A weak reduction wave at-0.4 V was due to the reduction in Pd(II) to Pd(0), and the deposition process wasirreversible. In electrowinning experiments, a maximum of92% palladium could be obtained.     

Measurements of the Ratio of Neutron Capture Cross Section of ~(71)Ga and ~(180)Hf to ~(197)Au From 0.5 to 3.0 MeV

The measurements of the ratio of neutron capture cross section of ~(71)Ga and ~(180)Hf to ~(197)Au werecarried out at 5SDH-2 tandem accelerator and 600 kV Cockroft-Walton accelerator. Neutrons wereproduced in the energy region from 0.5 MeV to 2.0 MeV by the T(p, n) reaction at 5SDH-2 tandemaccelerator, in the energy 3.0 MeV by the D(d, n) reaction at Cockroft-Walton accelerator, respectively.The activation technique was used in this work.     

SYNTHESIS OF (~3H-METHYL) TRINITROTOLUENE AND ITS APPLICATION TO TOXICOLOGICAL STUDY

In this paper, (2H- methyl) toluene was prepared by catalysed halogen- tritium substitution method from benzyl bromide, then it was nitrated to produce (8H- methyl) trinitrotoluene. The tritiated product was purified by thin- layer chromatography. At last, the pure 3H- TNT was obtained with specific radioactivity of 3.77 GBq/mmol. Radiochemical purity was over 98% and the ultraviolet absorption spectrum of tritiated TNT was conformed with that of standard sample. Using 3H- TNT as a tracer, its toxicokinetics was sudied in rats. The results showed that the toxicokinetics characteristics of TNT were quickly absorbed into the blood, Vd>2L/kg.h, long T1/2β and fixed accumulation with four routes of administration, TNT and its metabolites were mainly excreted by the urine. The half- life of TNT in the urine were 1,1- 24h. A trace of radioactivity of 3H- TNT and its metabolites could be detected in the urine on 7th day after administration (9.25×106Bq/kg).     

Measurement of Cross Sections for the Reaction ~(27)Al(n,p),~(56)Fe(n,p)and ~(64)Zn(n,2n)of 14.6MeV Neutrons and Simultaneous Evaluation of Some Cross Sections

1.Measurements The experiments were performed on 400 kV Cockcroft-Walton acceleratorof Nanjing University,using the T(d,n)~4He reaction to produce 14.6MeVneutrons.The energy of the incident deuterons was 200keV,the deuteroncurrent was 40μA,and the neutron yield was about 2×10~8 n/s.The ZnS neu-tron detector was used as flux monitor.Each sample to be measured was packedtogether in two standard sample foils of the same dimensions(2×1cm~2 rectang-lar foils and purities better than 99.5%)to form a sandwich so that they areirradiated in the same geometry.The γ-ray activities of the irradiated samplesand monitor foils were measured with a GEM-25210 type HPGe γ-spectrometer.The efficiency of this detector was determined with a ~(152)Eu standard γ source.     

Pigment analysis of a color-leaf mutant in Wandering Jew （Tradescantiafluminensis） irradiated by carbon ions

Many mutants of plant induced by heavy ion beam irradiation have been reported in recent years,but leaf anthocyan mutants induced by ion irradiation in evergreen were rarely found.In this study,a color-leaf mutant with purple leaves,stems and petals was isolated from clones of Wandering Jew irradiated by 95.8 MeV/u carbon ion beam.The concentration and histological distribution of leaf pigment were surveyed in wild type and mutant.In mutant,contents of total chlorophylls (Chl),chlorophyll a (Chl a),chlorophyll b (Chl b) and carotenoids (Car) decreased significantly,while concentration of the anthocyanins was 6.2-fold higher than that of wild type.Further composition analysis of anthocyanins by electrospray ionization mass spectrometry (ESI-MS) indicated that the purple pigmentation of leaves in mutant was caused by accumulation of petunidin anthocyanin.Microscopic examination showed that most petunidin anthocyanin accumulated in the lower epidermis,and little in vascular parenchyma of mutant,while there was no pigment in wild type.Meanwhile,in spongy parenchyma of mutant we observed little Chl,which the wild type abounds in.In conclusion,the color-leaf mutant of Wandering Jew induced by irradiation of carbon ions was improved in ornamental value,and it could be contribute to variation in level,component and distribution of foliar pigment.The possible mutation mechanisms were discussed.     

Effect of ~(103)Pd on proliferation and apoptosis of vascular smoothmuscle cells

This study aimed at the effect of γ-emitting radionuclide l03Pd on the proliferation and apoptosis of vascular SMCs (smooth muscle cells) in vitro. The cavy aortic SMCs were cultured with culture medium M-199. The experiments were carried out in two groups, one for proliferation test and the other for apoptosis test. In each group, 103Pd solutions with various radioactivities were respectively added to the culture solution to irradiate SMCs for 72 h, while non-radioactive palladium solution was added to the control. H-thymidine incorporation test and liquid scin-tillator were used to detect the effect of 103Pd on the proliferation of SMCs. Flow cytometer was used to detect the apoptotic SMCs. The inhibition rate of SMCs proliferation by 1.85 MBq 103Pd solution was 2.3%, which was not significant, while the inhibition rate increased from 41.6% to 91.3% as the 103Pd activity increased from 7.40 MBq to 37 MBq. The apoptosis rate of SMCs was extremely low (less than 4.0%) by 103Pd with activity from 1.85 M     

Level of natural radionuclides in foodstuffs and resultant annual ingestion radiation dose

The natural radioactivities in three major groups of foodstuff widely consumed in Upper Egypt were determined. The specific activities of ^226Ra, ^232Th, and ^40K in cereals, leguminosae, and flour were measured using γ-ray spectroscopy. Another group of hay, water, and soil samples from the same location were also analyzed. Hay samples were found to contain the highest radioactivity concentration among all the samples that were investigated. This increment could be due to the high water content in the shoots which tends to accumulate soluble radionuclides. The average calculated concentrations of soil samples in the present study exhibits the lowest values with respect to those from different countries. In the case of water samples, the average activities of both ^232Th and ^40K were similar to those for soil while ^226Ra was twice that of water sample. The annual ingestion dose from each radionuclide was calculated. The computed annual dose owing to daily intake of radium, thorium, and potassium via wheat flour, lentils, and bean in the present study （214.8 μSv） is ten times lower than the global average annual radiation dose （2400 μSv） from the natural radiation sources as proposed by UNSCEAR. The obtained results show that the dose values are quite low and carry insignificant radiation dose to the public.     

The cross section calculation of ~(112)Sn(α,γ) ~(116)Te reaction with different nuclear models at the astrophysical energy range

The theoretical cross section calculations for the astrophysical p process are needed because most of the related reactions are technically very difficult to be measured in the laboratory. Even if the reaction was measured,most of the measured reactions have been carried out at the higher energy range from the astrophysical energies.Therefore, almost all cross sections needed for p process simulation have to be theoretically calculated or extrapolated to the astrophysical energies.~(112)Sn(α,γ)~(116)Te is an important reaction for the p process nucleosynthesis. The theoretical cross section of ~(112)Sn(α,γ)~(116)Te reaction was investigated for different global optical model potentials,level density, and strength function models at the astrophysically interested energies. Astrophysical S factors were calculated and compared with experimental data available in the EXFOR database. The calculation with the optical model potential of the dispersive model by Demetriou et al., and the back-shifted Fermi gas level density model and Brink-Axel Lorentzian strength function model best served to reproduce experimental results at an astrophysically relevant energy region. The reaction rates were calculated with these model parameters at the p process temperature and compared with the current version of the reaction rate library Reaclib and Starlib.     

Interaction between uranium and humic acid （Ⅱ）： complexation, precipitation and migration behavior of U（Ⅵ） in the presence of humic substances

The complexation, precipitation, and migration behavior of uranium in the presence of humic acid (HA) or fulvic acid (FA) were investigated by cation exchange, ultrafiltration and dynamic experiment, respectively. The results showed that (i) complex equilibrium between the uranium and humic substances was achieved at approximately 72 h, (ii) the coordination number varied from 1:1 to 1:2 ( U(Ⅵ) : humic acid) as pH increased from 3 to 6; and (iii) , while the complex stability constant decreased when temperature increased, but increased with pH value. We found that the precipitation of uranyl could only be observed in presence of HA, and the precipitation was influenced by conditions, such as pH, uranium concentration, temperature, and the HA concentration. The maximum precipitation proportion up to 60% could be achieved in the condition of 40 mg/L HA solution at pH 6. We further observed that the migration behavior of uranium in soil in the presence of humic acid (HA) or fulvic acid (FA) was different from that in the presence of inorganic colloid, and the effect of humic substances (HS) was limited.     

High Spin States in Vdd-odd Nucleus ~(90)Nb

The high spin states of ~(90)Nb were populated through the fusion-evaporation reaction ~(76)Ge(~(19)F,5n)~(90)Nb. The 80 MeV ~(19)F beams was delivered by the HI-13 tandem accelerator in China Institute ofAtomic Energy. The ~(76)Ge target is 2.2 mg/cm~2 thick and evaporated on 10 mg/cm~2 lead backing. Theγ-rays from the reaction residues were recorded using 14 Compton suppressed HPGe-BGO spectrometers     

Determination of ~(210)Po and ~(210)Pb depositions in lichen and soil samples collected from K?prüba??-Manisa,Turkey

üIn this study, we aimed to determine the accumulations of ~(210) Po and ~(210) Pb in soil and lichen samples in K? prü bas??. The K? prü bas?? district is home to the largest uranium deposits in Turkey. To date, there has been no study recorded in the literature related to ~(210) Po and ~(210) Pb depositions in lichens in K? prü bas??. Six different lichen species(Cladonia convoluta, Parmelina tiliacea, Physcia stellaris, Pleurosticta acetabulum, Xanthoparmelia conspersa, and Xanthoria parietina) as well as soil samples were collected from seven sampling locations around K? prü bas??. Lichens were used as biomonitors for ~(210) Po and ~(210) Pb deposition. The ~(210) Po and ~(210) Pb activity concentrations were measured in all the samples by alpha spectrometry. The activity concentrations in the lichen samples ranged from 64 to 577 Bq kg~(-1) with an average of 266 Bq kg~(-1) for ~(210) Po and from 78 to 565 Bq kg~(-1) with an average of 333 Bq kg~(-1) for ~(210) Pb. The activity ratios of ~(210) Po/ ~(210) Pb ranged from 0.80 to 1.99. In the lichen species,the mean ~(210) Po activity values varied from 154 Bq kg~(-1) in Pleurosticta acetabulum to 390 Bq kg~(-1) in Xanthoparmelia conspersa. The range of the mean ~(210) Pb activity was between 153 Bq kg~(-1) in Cladonia convoluta and 378 Bq kg~(-1) in Parmelina tiliacea. In the soil samples, ~(210) Po and ~(210) Pb activity concentrations were ranged from14 to 1268 Bq kg~(-1) and from 19 to 1113 Bq kg~(-1),respectively. While the values of ~(210) Po and ~(210) Pb measured in the lichen samples are comparable with those of the literature, the results of ~(210) Po and ~(210) Pb in the soil taken from the uranium mine are higher than the results of the literature studies.