共查询到20条相似文献,搜索用时 15 毫秒
1.
S. Grace V. Meera S. A. Balakrishnan H. D. Sarma 《Journal of Radioanalytical and Nuclear Chemistry》1997,224(1-2):83-87
A study for separation and sequential recovery of uranium and plutonium from nitric acid solutions by extraction chromatography using tributyl phosphate (TBP)/Amberlite XAD7 as stationary phase is presented. Distribution ratios of actinides, lanthanides and fission products were obtained. The column capacity was investigated and actinides retention conditions were established. Finally, U-Pu sequential separation was studied as well as the U and Pu recovery yields from nitric solutions containing Am/fission products were determined. 相似文献
2.
R. Bilek R. Hampl Z. Putz L. Stárka 《Journal of Radioanalytical and Nuclear Chemistry》1987,108(3):159-168
The preparation of reagents, suitable for radioimmunoassay of 17-hydroxy-4-androsten-3-one /epitestosterone/ in body fluids is described. It includes a simplified synthesis of the immunogen, epitestosterone-3-/O-carboxymethyl/oxime coupled to bovine serumalbumin, its characterization and preparation of the radioligand [125I] iodohistaminyl derivative of epitestosterone. The assay protocol for epitestosterone detection in urine avoiding extraction is described and the reliability criteria of the method are given. 相似文献
3.
Kanchan Kothari Ramji Lal M. R. A. Pillai 《Journal of Radioanalytical and Nuclear Chemistry》1995,196(2):331-338
A direct radioimmunoassay for the measurement of progesterone in human serum is described. Progesterone 11-hemisuccinate was conjugated to tyrosine methyl ester (TME) by the mix anhydride method and then iodinated using chloramine-T. The radiochemical purity of different batches of125I-progesterone was greater than 95% and showed 70–75% binding with excess antibody. Progesterone 11-hemisuccinate was coupled with BSA and injected to rabits. Antisera collected after three booster injections and having aK value of 1·1091/M was selected for the assay. Significant reduction in binding with antibody was seen when hormone free serum was used in the assay system. Various blocking agents were tried to reduce the serum effects and none of them were found satisfactory. From a series of optimization experiments, an assay was developed without the use of blocking agents. This assay used a much higher concentration of antibody along with lower amount of serum sample (50 l). The optimized assay has a sensitivity of 0.5 nj/ml and a working range of 0.5 to 100 ng/ml. Serum samples were analyzed analysis showed good correlation between the results obtained from the present system and the DPC kit. (Y=0.93X+0.5,r=0.93, forn=25). 相似文献
4.
L. Fukal J. Prošek P. Rauch Z. Sova J. Káš 《Journal of Radioanalytical and Nuclear Chemistry》1987,109(2):383-391
Aflatoxin B1 was assayed by radioimmunoassay (RIA) using125I-labelled antigen. The immunoreactivity of the radioligand applied is very close to the immunoreactivity of free aflatoxin B1. The logit-log analysis was used to select the best separation of free and bound radioligand. The adsorption of the free radioligand on dextran-coated charcoal was found to be superior from the viewpoint of the assay sensitivity and accuracy. The detection limit of aflatoxin B1 was about 10 pg per tube. The assay accuracy was estimated to 3.3% in intraassay and to 7.0% in interassay. 相似文献
5.
R. M. Baldwin T. H. Lin H. S. Winchell 《Journal of Radioanalytical and Nuclear Chemistry》1981,65(1-2):269-277
o-Iodobenzamide is a stable compound which is labeled quantitatively by heating with no-carrier-added123I-NaI in ethanol. The123I product is relatively inert biologically, being resistant toin vivo deiodination or hydrolysis, in rats and dogs, for several hours. Furthermore, it appears to be freely diffusible, distributing
itself in the body according to the extravascular fluid space, with some localization in the liver, and little tendency for
excretion into the urine or bile. The brain uptake and brain-blood ratio is higher than that of iodoantipyrine, and allows
imaging the brain in dogs. The product is also taken up by induced myocardial infarcts and transplanted tumors in rats. Substitution
of the amide function with single alkyl groups does not greatly alter thein vivo characteristics except at long-chain length where hepatobiliary excretion predominates. Substitution of both amide hydrogens,
however, results in a different pattern, with high blood binding and increased excretion. Conversion to more polar functionalities,
such as the hydrazide or hydroxamic acid, also leads to hepatobiliary excretion. 相似文献
6.
Norgren M Notley SM Majtnerova A Gellerstedt G 《Langmuir : the ACS journal of surfaces and colloids》2006,22(3):1209-1214
Lignin model surfaces were prepared from aqueous alkaline solutions by spin-coating on silica wafers. Films of thicknesses between 20 and 140 nm were easily made by variations in the spinning rate or in the lignin concentration. The roughnesses of the lignin surfaces were relatively low, approximately 1.1 nm (rms) on an area of 25 microm2, as determined by atomic force microscopy imaging. The stability of the lignin films in aqueous solutions was found to be excellent. No changes in the thickness of model surfaces immersed in slightly alkaline solutions (pH 9.2) could be detected even after 5 h soaking. A 10 percent reduction in the thickness of the lignin film was observed after 5 h of exposure to a solution containing 0.1 M NaCl. This novel preparation method opens great possibilities for further fundamental studies, where interactions between lignin and other substances are of interest to investigate. 相似文献
7.
Gao Feng Zhou Meiying Zhao Xialing Zhang Sunxi Wang Guoping 《Journal of Radioanalytical and Nuclear Chemistry》1996,206(1):151-154
Endothelin (ET) is a novel endothelium-derived vasoconstrictive peptide, purified from porcine aortic endothelial cells.125I-ET was prepared by lodogen method and purified by HPLC, the specific activity was 62.9 TBq/mmol. The stability of125I-ET was investigated in different storage conditions by radioimmunoassay. 相似文献
8.
Chunfu Zhang Yongxian Wang Haibin Tian Duan Zhiyin 《Journal of Radioanalytical and Nuclear Chemistry》2002,252(1):161-163
We studied the preparation method of 125I seeds and found that silver was a good carrier body for 125I and the ion-exchange technique was simple and effective for the preparation. Carrier iodine was critical for dose uniformity of the seeds and the minimal pH value for the reaction was 6.5. This paper provided valuable data for the development and preparation of 125I seed. 相似文献
9.
This paper describes the counting efficiency and detection limit of a thyroidal 125I monitoring system. Two systems were used: (1) M1 was composed of only a survey meter for 125I (SM) having a NaI(T1) crystal of 2 in phi X 5 mmt and (2) M2 was composed of the SM having an output terminal for spectroscopy and a multichannel pulse height analyzer. The counting efficiency was determined by using an anthropomorphic neck phantom embedded four simulated thyroids of 17, 20.5, 31 and 40 ml including 125I solution. The counting efficiency between 0 degrees and 45 degrees to the direction from the center of the thyroid to the front of the neck coincided within -4%. The efficiency of M1 ranged from 7.9 to 1.8% as the distance between the probe and the neck increased from 0 to 5 cm. Similarly the efficiency of M2 ranged from 8.3 to 2.2%. The detection limit of M1 ranged from 7 to 34 Bq, and the limit of M2 ranged from 1 to 5.1 Bq. M2 system was applied to monitoring a worker performing iodination with Na125I of 74 MBq. Both monitoring systems proved to sensitively detect thyroidal 125I within the uncertainty +/- 10%. 相似文献
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Francesconi LC Zheng Y Bartis J Blumenstein M Costello C De Rosch MA 《Inorganic chemistry》2004,43(9):2867-2875
[99mTcO] apcitide (99mTcO(P246)), the technetium complex of the 13 amino acid, apcitide, cyclo-(D-Tyr-Apc-Gly-Asp-Cys)-Gly-Gly-Cys(Acm)-Gly-Cys(Acm)-Gly-Gly-Cys-NH2, where Apc is L-[S-(3-aminopropyl)]cysteine (an arginine mimetic) and Acm is the acetamidomethyl protecting group, has high affinity and selectivity for the GPIIb/IIIa receptor that is expressed on the membrane surface of activated platelets and plays an integral role in platelet aggregation and thrombus formation. Bibapcitide, a 26 amino acid, bis-succinimidomethyl ether-linked dimer of the peptide apcitide has been formulated as a single-vial, lyophilized kit having the trade name AcuTect. When sterile, nonpyrogenic sodium pertechnetate (99mTcO4-) in 0.9% sodium chloride is added to the AcuTect radiopharmaceutical kit and the resulting kit is heated, [99mTcO] apcitide forms. This is the first radiopharmaceutical to target acute deep vein thrombosis (DVT) in the lower extremities. We report here the preparation, purification, and isolation of the 99Tc complex of apcitide and its characterization to determine the mode of binding of Tc to apcitide. [99TcO] apcitide was prepared, on the macroscopic level, by reaction of [99TcOCl4]- with apcitide, purified by preparative HPLC and isolated as a trifluoroacetate salt. [99TcO] apcitide can also be formed from the reaction of bibapcitide and 99TcO4- in the presence of Sn(II) and glucoheptonate at 80 degrees C, conditions that mimic the radiopharmaceutical kit preparation. FTIR data show a Tc=O stretch at 961.2 cm(-1), in the range observed for anionic [TcVO]3+ amide thiolate complexes. The mass spectral data is in agreement with the formula, [C51H73O20N17S5Tc]-, consistent with retention of Acm groups and the Tc binding in the Gly11-Gly12-Cys13 region of the peptide. Despite significant spectral overlap due to numerous similar amino acids, all protons of apcitide and [99TcO] apcitide were unambiguously assigned. The observation of two nonequivalent Acm groups and the observation of only 10 NH-CH cross-peaks in the TOCSY and COSY spectra of [99TcO] apcitide (NH-CH cross-peaks were absent for Gly11-Gly12-Cys13), compared to all 13 cross-peaks found in apcitide, provided compelling evidence to support the 99Tc binding to the terminal Gly11-Gly12-Cys13 region of apcitide. 相似文献
12.
L. Fukal J. Prosek P. Rauch Z. Sova J. Káš 《Journal of Radioanalytical and Nuclear Chemistry》1987,108(5):259-268
Assay conditions for the radioimmunoassay for aflatoxin B1 using125I-radiolabel and dextran-coated charcoal for the separation of free and bound radioligand were optimized. Casein was chosen as the best protecting protein /in contrast with human serum albumin, -globulin and gelatine/. The most suitable incubation conditions are at 4°C for 18 h in darkness, radioligand sorption on the dextrancoated charcoal takes place 30 min at 4°C and the antiserum is diluted in order to reach zero specific binding in the range between 35 and 50%. 相似文献
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N. E. Shchepina V. V. Avrorin G. A. Badun G. A. Alexandrova S. E. Ukhanov V. M. Fedoseev S. B. Lewis I. I. Boiko 《Chemistry of Heterocyclic Compounds》2009,45(7):796-801
A chemonuclear method of synthesis is proposed for obtaining difficultly available phenyl-substituted derivatives of quinoline
labeled with tritium. The ion-molecule reaction of free phenyl cations, generated on β-decay of tritium, with the nucleophilic
centers of heterocyclic compounds is the basis of the synthesis. The onium derivatives synthesized possess significant inhibitory
antimicrobial activity and are promising for a detailed study of the reaction mechanisms and metabolic processes using radioactive
indicators. 相似文献
16.
分别以香叶醇、橙花醇及芳樟醇为原料,经SeO2和t-BuOOH氧化、NaBH4还原得到8-羟基香叶醇、8-羟基橙花醇及8-羟基芳樟醇;利用乙酰化反应和苯甲酰化反应分别制备了这三个二醇化合物的乙酰化和苯甲酰化衍生物;并利用气相色谱-电子电离质谱仪(GC-EIMS)和液相色谱-电喷雾质谱仪(LC-ESIMS)分析了合成产物的光谱性质.结果显示,以GC-EIMS表征合成产物时,除苯甲酰化衍生物呈现较弱的分子离子峰外,其他几个产物均无分子离子峰信号. 相似文献
17.
Toriya S Tamura Y Takei T Fuji M Watanabe T Chikazawa M 《Journal of colloid and interface science》2002,255(1):171-176
The silica-pillared derivatives from kanemite (NaHSi(2)O(5).3H(2)O) were prepared by intercalation of dialkyldimethylammonium (DADMA) ion and pillaring with tetraethylorthosilicate. The formation of silica pillars between the silicate sheets was demonstrated by X-ray diffraction, (29)Si CP/MAS NMR, and TEM observation. The basal spacing depended on the chain length of DADMA. Nitrogen adsorption study showed that the specific surface area was enlarged over 1000 m(2) g(-1) by the pillaring and that the pore size was in the micropore region. Water and benzene adsorption isotherms revealed that the surface properties of the pillared derivatives show hydrophobic character. 相似文献
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125I-labelled human-C-peptide was prepared by chloramin T method, enzymic method and active ester method, respectively. Using respective 125I-labelled human-C-peptides in human proinsulin-C-peptide RIA, we compared the binding (Bo/T%) to antibody, displacement by standard human-C-peptide, the recovery test and stability. The usable 125I-labelled antigen for human proinsulin-C-peptide RIA could be prepared by chloramin T method and enzymic method wich labelled 125I to tyrosyl human proinsulin connecting peptide, and active ester method which conjugates 125I-labelled active ester to human proinsulin connecting peptide. The differences among those 125I-labelled antigens was not observed in displacement (B/Bo%) by standard human-C-peptide and the recovery test. In the case of constant preparation of 125I-labelled antigen for RIA, the enzymic method was the best from the viewpoint the reaction ratio is stable and stability of Bo/T% is good. 相似文献
20.
Richard K. Johnson Audrey Zink-Sharp Wolfgang G. Glasser 《Cellulose (London, England)》2011,18(6):1599-1609
Amidation and ionic complexation were evaluated as surface modification treatments for TEMPO-oxidized nanocelluloses (TONc),
using octadecylamine (ODA) as the modifying compound. Effects of the two treatments on TONc with respect to degree of ODA
substitution, surface hydrophobicity, crystalline characteristics, and thermal decomposition properties were investigated,
respectively, with elemental analysis, contact angle measurements, X-ray diffraction spectroscopy, and thermogravimetric analysis.
Both treatments resulted in complete substitution of TONc surface carboxyl groups with ODA, transforming TONc surfaces from
hydrophilic to hydrophobic. A slightly greater than one-to-one ODA-to-carboxyl ratio was found for the ionic complexation
product, giving it a more hydrophobic character than the amidation product. Furthermore, the ionic complexation product was
found to be surprisingly stable in acidic environment and was able to resist dissociation at fairly low pH. TONc from both
treatments could be readily dispersed in organic solvents of wide-ranging polarities, making ionic complexation an equally
effective surface modification approach as amidation for the hydrophobization of TONc surfaces. It was also found, through
X-ray diffraction results that the crystalline structure of TONc was preserved even after the surface modification treatments.
Finally, the thermal stability of TONc was slightly increased as a result of the surface modification treatments as evidenced
by slight shifts to higher values of TONc thermal decomposition temperature. 相似文献