Showing 1-28 of 28 results for "291110"
Keunpoong Lim et al.
Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine, 140, 294-299 (2018-08-12)
In the process of developing [18F]FBEM coupled target peptide, we have instituted a robust automated synthesis of [18F]FBEM, a sulfhydryl (-SH) site specific agent for radiolabeling of peptides and proteins. The radiosynthesis generated 1.67-3.89 GBq (45.1-105.1 mCi, 7.5-18.8% non-decay corrected yield)...
T Colomina et al.
Veterinary and human toxicology, 33(2), 121-124 (1991-04-01)
The effects of repeated ip administration of diethylenetriaminepentaacetic acid (DTPA), Kryptofix 222, 1,4,7,10,13,16-hexaoxacyclooctadecane (18-crown-6), ethylenglycol-bis-(beta-amino-ethylether)-N,N'-tetraacetic acid (EGTA), and Kryptofix 5 on the distribution and excretion of sc-injected strontium were investigated in male Swiss mice. Groups of 20 animals received 95...
J M Llobet et al.
Veterinary and human toxicology, 34(1), 7-9 (1992-02-01)
Diethylenetriaminepentaacetic acid (DTPA), ethylenglycolbis-(beta-amino-ethylether)-N,N-tetraacetic acid (EGTA), tartaric acid, KRYPTOFIX 222, and KRYPTOFIX 5 were evaluated for their efficacy in mobilization of strontium from the body of mice which had received 20 sc injections of strontium nitrate (95 mg/kg/injection) for 4...
D Pan et al.
Bioorganic & medicinal chemistry letters, 8(11), 1317-1320 (1999-01-01)
5'-Deoxy-5'-fluoro-O4-methylthymidine was synthesized by the reaction of the corresponding 5'-O-tosylate with KF in the presence of Kryptofix [222] and coupled to a 5'-phosphoramidite-activated CPG-bound oligodeoxynucleotide. The sequence of reactions and purifications were accomplished within 4 h, a necessary condition of...
J M Llobet et al.
Health physics, 65(5), 541-544 (1993-11-01)
90Sr has a physical half-life of sufficient duration to make it a potentially dangerous contaminant from nuclear accidents and radioactive wastes. In the present study, the efficacy of 16 compounds as potential chelators of strontium was tested in vitro. Strontium...
T Chaly et al.
International journal of radiation applications and instrumentation. Part B, Nuclear medicine and biology, 16(4), 385-387 (1989-01-01)
A simple procedure for the detection of 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo (8.8.8) hexacosane (Kryptofix 2.2.2) in the final solution of [18F]FDG prepared by the aminopolyether supported nucleophilic substitution of 1,3,4,6-tetra-O-acetyl 2-O-trifluoromethanesulfonyl-beta-D-mannopyranose (Hamacher et al., 1986) has been developed. Presence of Kryptofix 2.2.2 in...
B H Mock et al.
Nuclear medicine and biology, 24(2), 193-195 (1997-02-01)
A color spot test is described that can confirm the absence of Kryptofix 2.2.2 in 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG) in less than 5 min. Pretreated strips of plastic-backed silica gel 60 thin-layer chromatographic medium, saturated with iodoplatinate reagent, are over-spotted with separate...
A Loiseau et al.
Biochimica et biophysica acta, 1238(2), 107-117 (1995-09-13)
The kinetics of the electroneutral exchange of competing sodium and potassium with protons across the membrane of large unilamellar vesicles (LUV) were determined at two pH values when transport was induced by the simultaneous presence of (222)C10-cryptand and FCCP (proton...
Peter J H Scott et al.
Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine, 65(12), 1359-1362 (2007-06-22)
4,7,13,16,21,24-Hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane (Kryptofix 2.2.2) is used in the routine preparation of [18F]-labeled tracers employed in positron emission tomography (PET) imaging. Confirming the absence of Kryptofix in radiopharmaceuticals is a quality control criterion required before they can be released for human use....
Ryuji Nakao et al.
Nuclear medicine and biology, 35(2), 239-244 (2008-03-04)
A practical, sensitive and rapid analytical method was established and validated for chemical impurity tests of 2-deoxy-2-fluoro-d-glucose (FDG), 2-deoxy-2-chloro-d-glucose (ClDG) and Kryptofix 2.2.2 (K-222) in [18F]FDG. This method was based on precolumn derivatization with ultraviolet (UV) detection. FDG and ClDG...
David Kryza et al.
Nuclear medicine and biology, 35(2), 255-260 (2008-03-04)
We developed a new fully automated method for the radiosynthesis of [18F]fluorocholine by modifying the commercial 2-[18F]fluoro-2-d-deoxy-glucose ([18F]FDG) synthesizer module (GE TracerLab MX, formerly Coincidence). [18F]Flurocholine was synthesized by (18)F-fluoroalkylation of N,N-dimethylaminoethanol using [18F]fluorobromomethane as fluoromethylating agent. [18F]Fluorobromomethane was produced...
B L Trend et al.
Biophysical journal, 57(4), 829-834 (1990-04-01)
Most polyelectrolyte theories of the effect of ions on the thermal melting of DNA assume that the predominant influence of the cations comes through their charge. Ion size and structure are treated, for analytic convenience, as negligible variables. We have...
Dmitri V Konarev et al.
Dalton transactions (Cambridge, England : 2003), 49(46), 16821-16829 (2020-11-13)
The reduction of copper(ii) octafluoro- {CuII(F8Pc)} and hexadecafluorophthalocyanines {CuII(F16Pc)} by NaCpCo(CO)2 in the presence of cryptand[2.2.2] yields new crystalline {cryptand(Na+)}[CuII(F8Pc)˙3-]-·2C6H4Cl2 (1) and {cryptand(Na+)}2[CuII(F16Pc)4-]2-·C6H14 (2) salts. Together with two previously characterized salts of CuII(FxPc) (x = 8 and 16), this allows...
Dynamers at the solid-liquid interface: controlling the reversible assembly/reassembly process between two highly ordered supramolecular guanine motifs.
Artur Ciesielski et al.
Angewandte Chemie (International ed. in English), 49(11), 1963-1966 (2010-02-06)
Direct analysis of Kryptofix 2.2.2 in 18FDG by gas chromatography using a nitrogen-selective detector.
R A Ferrieri et al.
Nuclear medicine and biology, 20(3), 367-369 (1993-04-01)
Andy Woodruff et al.
Journal of chromatography. A, 997(1-2), 33-39 (2003-07-02)
A 2.2.2 cryptand-based anion exchanger was recently introduced as a commercial product. This new technology relies on a covalently bonded 2.2.2 cryptand, which allows one to selectively control the capacity of the column simply by the choice of eluent. This...
Jeff E Prest et al.
Journal of chromatography. A, 1260, 239-243 (2012-09-20)
This work shows how the inclusion of cryptand 222 as a leading electrolyte additive in isotachophoresis affects the electrophoretic mobilities of alkali metal cations. Using isotachophoresis the separation of alkali metals can be difficult due to the similar electrophoretic mobilities...
S M Moerlein et al.
International journal of radiation applications and instrumentation. Part A, Applied radiation and isotopes, 40(9), 741-743 (1989-01-01)
Radiopharmaceutical solutions of 2-[18F]fluoro-2-deoxy-D-glucose (2-[18F]FDG) prepared via an aminopolyether-supported nucleophilic-substitution mechanism were analyzed for contaminant 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo-[8,8,8]-hexacosane (Kryptofix 2.2.2). Washing the C18-immobilized [18F]fluoro-tetraacetylated intermediate with 10 mL 0.1 M HCl was found to remove impurity Kryptofix 2.2.2 from the final product....
Ying Ma et al.
Nuclear medicine and biology, 29(1), 125-129 (2002-01-12)
A high-performance liquid chromatography-tandem mass spectrometric method (LC/MS/MS) was developed and validated for the quantitative analysis of Kryptofix (K-222) in the radiopharmaceuticals of 2-deoxy-2-[(18)F] fluoro-D-glucose (2-[(18)F]FDG) and 3-(3-((3-fluoropropyl)thio)-1,2,5-thiadiazol-4-yl)-1,2,5,6-tetrahydro-1-methylpyridine (FPTZTP). With an internal standard, the limit of quantitation for K-222 was...
Alexey P Kostikov et al.
Nature protocols, 7(11), 1956-1963 (2012-10-06)
N-Succinimidyl 3-(di-tert-butyl[(18)F]fluorosilyl)benzoate ([(18)F]SiFB) is a highly reactive prosthetic group for radiolabeling of proteins for use in positron emission tomography (PET). It is similar to N-succinimidyl-4-[(18)F]fluorobenzoate ([(18)F]SFB), the 'gold-standard' prosthetic group for protein (18)F-labeling, but can be synthesized using a much...
A Kumar et al.
Clinical chemistry, 34(9), 1709-1712 (1988-09-01)
We report spectrophotometric methods for quantifying sodium and potassium in serum and plasma without sample pretreatment or solvent-extraction steps. The methods are based on novel chromogenic ionophores characterized by molecular structures highly preorganized for binding, which result in exceptionally high...
B H Mock et al.
Nuclear medicine and biology, 23(4), 497-501 (1996-05-01)
Simple changes in the chemistry, plumbing, and programming of the Siemens-CTI chemistry process control unit (CPCU) effectively double its output by enabling two back-to-back "1-pot" syntheses of 2-[18F]fluoro-2-deoxy-D-glucose in a single unit. Replacement of Kryptofix 2.2.2 with tetramethylammonium carbonate and...
L E Vanatta et al.
Journal of chromatography. A, 1085(1), 33-36 (2005-08-19)
Improved ion-chromatographic approaches for measuring trace chloride in nitric acid are presented. Two columns, the IonPac Cryptand A1 and a higher-capacity Cryptand prototype, were tested and compared. Also, the use of a Continuously Regenerated Anion Trap Column (CR-ATC) was evaluated...
Vladimir Ya Lee et al.
Journal of the American Chemical Society, 128(35), 11643-11651 (2006-08-31)
((t)Bu(2)MeSi)(2)Sn=Sn(SiMe(t)Bu(2))(2) 1, prepared by the reaction of (t)Bu(2)MeSiNa with SnCl(2)-diox in THF and isolated as dark-green crystals, represents the first example of acyclic distannene with a Sn=Sn double bond that is stable both in the crystalline form and in solution....
D B Gomis et al.
The Analyst, 115(1), 89-91 (1990-01-01)
A spectrofluorimetric method for the determination of ultratrace amounts of lead and cadmium is described based on the sequential extraction of the ternary ion-association complexes formed between the cation, a cryptand as the ligand and eosin as a counter ion....
Yexing Lao et al.
Nuclear medicine communications, 33(5), 498-502 (2012-02-15)
The cryptand Kryptofix 2.2.2 is used extensively as a phase-transfer reagent in the preparation of [18F]fluoride-labelled radiopharmaceuticals. However, it has considerable acute toxicity. The aim of this study was to develop and validate a method for rapid (within 1 min)...
D L Alexoff et al.
International journal of radiation applications and instrumentation. Part A, Applied radiation and isotopes, 42(12), 1189-1193 (1991-01-01)
The 2.2.2 cryptand [4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo-(8.8.8)-hexacosane] was trapped efficiently on Dowex AG50W-X8 (100-200 mesh) cation exchange resin. The concentration of the 2.2.2 cryptand in water with 0.1-2% methanol, or in 1 N HCl, was decreased by a factor of > 4000 using...
M Castaing et al.
The Journal of membrane biology, 89(3), 251-267 (1986-01-01)
The kinetics of K+ and Na+ transport across the membrane of large unilamellar vesicles (L.U.V.) were compared at two pH's, with two carriers: (222)C10-cryptand (diaza-1,10-decyl-5-hexaoxa-4,7,13,16,21,24-bicyclo[8.8.8.]+ ++hexacosane) and valinomcyin, i.e. an ionizable macrobicyclic amino polyether and a neutral macrocyclic antibiotic. The...

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