Science.gov

Sample records for 18f fluoride ion

  1. Cyclotron production of [18F]fluoride ion and [18F]fluorine gas and their medical applications

    NASA Astrophysics Data System (ADS)

    VanBrocklin, H. F.; O'Neil, J. P.

    1997-02-01

    One of the newest low energy cyclotrons for the production of positron emitting isotopes has been sited at Lawrence Berkeley National Laboratory. This prototype CTI RDS-111, proton only, 11 MeV, negative ion machine is capable of producing GBq quantities of fluorine-18 for radiopharmaceutical applications. A CTI designed target changing system developed for this cyclotron can hold up to eight small targets. We have tested two small high pressure CTI silver body target designs for the production of [18F]fluoride ion and compared them to the CTI RDS-112 style low pressure target. The high pressure target can produce up to 100% more activity for a given time and beam current with improved saturation yields. A high pressure aluminum RDS-112 gas target has been used to produce [18F]F2. The fluoride ion produced from this machine has been used to label fluorodeoxyglucose to trace glucose metabolism in patients and the fluorine gas has been used to label fluoro-meta-tyrosine to image therapeutic response to gene therapy in Parkinsonian monkeys.

  2. Rapid and Efficient Radiosyntheses of Meta-substituted [18F]Fluoroarenes from [18F]Fluoride Ion and Diaryliodonium Tosylates within a Microreactor

    PubMed Central

    Chun, Joong-Hyun; Lu, Shuiyu; Pike, Victor W.

    2011-01-01

    Effective methods for the introduction of the short-lived positron-emitter fluorine-18 (t1/2 = 109.7 min) at high specific radioactivity into fluoroarenes are valuable for the development of radiotracers for molecular imaging with positron emission tomography. Here we have explored the scope of the radiofluorination of diaryliodonium salts with no-carrier-added [18F]fluoride ion for the preparation of otherwise difficult to access meta-substituted [18F]fluoroarenes. A microfluidic reaction platform was used to establish optimal radiochemical yields. Rapid, high yielding and selective radiofluorinations were achieved in unsymmetrical diaryliodonium tosylates (ArI+Ar’TsO−) in which Ar carried either a meta electron-withdrawing (CN, NO2, CF3) or a meta electron-donating (Me or MeO) group, and in which the partner aryl group (Ar’) was relatively electron-rich, such as Ph, 3-Me-C6H4, 4-MeO-C6H4, 2-thienyl or 5-Me-2-thienyl. The radiofluorination of appropriate diaryliodonium tosylates is therefore a generally useful method for the preparation of simple [18F]m-fluoroarenes ([18F]ArF). PMID:22016665

  3. Production and Transport of Gaseous (18)F-Synthons: (18)F-Acyl Fluorides.

    PubMed

    Jiang, Huailei; DiMagno, Stephen G; DeGrado, Timothy R

    2015-12-01

    Fluorine-18 ((18)F, T 1/2=109.7 min) is a positron-emitting isotope that has found extensive application as a radiolabel for positron emission tomography (PET). Although gaseous (11)C-CO2 and (11)C-CH4 are practically transported from cyclotron to radiochemistry processes, (18)F-fluoride is routinely transported in aqueous solution because it is commonly produced by proton irradiation of (18)O-enriched water. In most cases, subsequent dry-down steps are necessary to prepare reactive (18)F-fluoride for radiofluorination. In this work, a simple module was designed to generate gaseous (18)F-acyl fluorides from aqueous (18)F-fluoride solution by solid phase (18)F-radiofluorination of acyl anhydride. The gaseous (18)F-acyl fluorides were purified through a column containing Porapak Q/Na2SO4, resulting in high yields (>86%), purities (>99%) and specific activities (>1200 GBq/μmol). Prototypic (18)F-acetyl fluoride ((18)F-AcF) was readily transported through 15 m of 0.8 mm ID polypropylene tubing with low (0.64 ± 0.12 %) adsorption to the tubing. Following dissolution of (18)F-AcF in solvent containing base, highly reactive (18)F-flouride was generated immediately and used directly for (18)F-labeling reactions. These data indicate that (18)F-acyl fluorides represent a new paradigm for preparation and transport of anhydrous, reactive (18)F-fluoride for radiofluorinations.

  4. Bone metabolic activity measured with positron emission tomography and [[sup 18]F] fluoride ion in renal osteodystrophy: Correlation with bone histomorphometry

    SciTech Connect

    Messa, C.; Goodman, W.G.; Hoh, C.K.; Choi, Y.; Nissenson, A.R.; Salusky, I.B.; Phelps, M.E.; Hawkins, R.A. )

    1993-10-01

    The authors evaluated the bone metabolic activity in patients with renal osteodystrophy using positron emission tomography and [[sup 18]F] fluoride ion. Eight patients had secondary hyperparathyroidism (HPT), and three had low-turnover bone disease. Eleven normal subjects were also studied, and three of the eight HPT patients were reevaluated after therapy. A rate constant (K) describing the net transport of [[sup 18]F] fluoride ion into a bound compartment in bone was calculated using both a three-compartment model and Patlak graphical analysis. Values of K were compared with biochemical data and with histomorphometric indices. The results indicate that K is significantly higher (P < 0.01) in HPT patients than in normal subjects and patients with low-turnover bone disease. Values of K correlated with serum alkaline phosphatase (r = 0.81) and PTH (r = 0.93) levels and with histomorphometric indices of bone formation rate (r = 0.84, P < 0.01) and eroded perimeter (r = 0.77, P < 0.05). Values of K decreased by 40 and 30%, respectively, in two patients who underwent parathyroidectomy and medical therapy. Positron emission tomography studies of bone using [[sup 18]F] fluoride ion can differentiate low turnover from high turnover lesions of renal osteodystropy and provide quantitative estimates of bone cell activity that correlate with histomorphometric data.

  5. [18F]fluorination/decarbonylation: new route to aryl [18F]fluorides.

    PubMed

    Chakraborty, P K; Kilbourn, M R

    1991-01-01

    A new route to aryl [18F]fluorides without electron withdrawing ring substituents has been developed. [18F]Fluorobenzaldehydes, prepared from no-carrier-added (NCA) [18F]fluoride using nucleophilic aromatic substitution of fluoro or nitro groups, were decarbonylated using palladium on charcoal (Pd-C). By this approach 2-methoxy-4-nitrobenzaldehyde was converted to NCA 3-[18F]fluorophenol (25-30%, EOB) and 4-fluoro-2-methoxy-5-methylbenzaldehyde to carrier-added (CA) 3-[18F]fluoro-4-methylphenol (30-40%, EOB). Overall synthesis time was about 2 h. Since the 4-fluoro-2-methoxy-5-methylbenzaldehyde was in turn prepared by methylation and regiospecific formylation of 3-fluoro-4-methylphenol, the overall process represents use of a removable activating group for nucleophilic aromatic substitution with [18F]fluoride for preparation of CA and NCA aryl [18F]fluorides.

  6. Fluorine-18 labeling of small molecules: the use of 18F-labeled aryl fluorides derived from no-carrier-added [18F]fluoride as labeling precursors.

    PubMed

    Wuest, F

    2007-01-01

    The favourable long-half life, the ease of production and the low energy of the emitted positron make 18F an ideal radionuclide for PET imaging. Radiochemistry of 18F basically relies on two distinctive types of reactions: nucleophilic and electrophilic reactions. All syntheses of 18F-labeled radiotracers are based on either [18F]fluoride ion or [18F]fluorine gas as simple primary labeling precursors which are obtained directly from the cyclotron. They can be applied either directly to the radiosynthesis or they can be transformed into more complex labeling precursors enabling the multi-step build-up of organic tracer molecules. The topic of this review is a survey on the application of several 18F-labeled aryl fluorides as building blocks derived from no-carrier-added (n.c.a.) [18F] fluoride to build up small monomeric PET radiotracers at high specific radioactivity by multi-step synthesis procedures.

  7. Production of the PET bone agent (18)F-fluoride ion, simultaneously with (18)F-FDG by a single run of the medical cyclotron with minimal radiation exposure- a novel technique.

    PubMed

    Kumar, Rajeev; Sonkawade, Rajendra G; Tripathi, Madhavi; Sharma, Punit; Gupta, Priyanka; Kumar, Praveen; Pandey, Anil K; Bal, Chandrasekhar; Damle, Nishikant Avinash; Bandopadhayaya, Gurupad

    2014-01-01

    Our aim was to establish an easy and convenient procedure for the preparation of fluorine-18-sodium fluoride ((18)F-NaF) for bone positron emission tomography (PET) during routine (18)F-FDG production using the Explora FDG4 radiochemistry module (EFRM) by single run of Cyclotron with negligible radiation exposure. We compared three techniques for (18)F-NaF production during routine PET radiochemistry at our setup. In one method we used synthesis module and in other two methods we did not. In the first and third method, F-18 was directly extracted from the V-vial and in the second method, (18)F-NaF was extracted by post processing from the EFRM. In the first method, F-18 was extracted directly from V-vial manually by opening the V-vial cap. In the second method, Explora FDG-4 Module was used. First, F-18 was transferred from the V-vial. Then, after post processing in EFRM, pure F-18 was obtained in the product vial. In the third method, pure F-18 was obtained in the product vial with the help of a mechanical robotic arm. The above were followed by routine quality control of (18)F-NaF produced by each method. Results of quality control of the (18)F-NaF obtained by all three methods satisfied all parameters prescribed by the United States Pharmacopeia (USP) and the British Pharmacopeia (BP) including biological, physical and chemical specifications. The radiochemical purity was 98.5±1.5% with Rf 0.006. The level of Kryptofix-222 (K222) in (18)F-NaF was within the prescribed limit. Mean pH of (18)F-NaF was 6.0±1.5. The exposure rate around the hot cell was negligible. In conclusion, from the results it was obvious that by our method number three (18)F-NaF was directly obtained from the V-vial using mechanical robotic arms. This method was the most appropriate with minimized radiation exposure to the handling Radiochemist and was also saving time as compared to the other two methods.

  8. 18F-Fluoride and 18F-Fluorodeoxyglucose Positron Emission Tomography After Transient Ischemic Attack or Minor Ischemic Stroke

    PubMed Central

    Jenkins, William S. A.; Irkle, Agnese; Moss, Alastair; Sng, Greg; Forsythe, Rachael O.; Clark, Tim; Roberts, Gemma; Fletcher, Alison; Lucatelli, Christophe; Rudd, James H. F.; Davenport, Anthony P.; Mills, Nicholas L.; Al-Shahi Salman, Rustam; Dennis, Martin; Whiteley, William N.; van Beek, Edwin J. R.; Dweck, Marc R.; Newby, David E.

    2017-01-01

    Background— Combined positron emission tomography (PET) and computed tomography (CT) can assess both anatomy and biology of carotid atherosclerosis. We sought to assess whether 18F-fluoride or 18F-fluorodeoxyglucose can identify culprit and high-risk carotid plaque. Methods and Results— We performed 18F-fluoride and 18F-fluorodeoxyglucose PET/CT in 26 patients after recent transient ischemic attack or minor ischemic stroke: 18 patients with culprit carotid stenosis awaiting carotid endarterectomy and 8 controls without culprit carotid atheroma. We compared standardized uptake values in the clinically adjudicated culprit to the contralateral asymptomatic artery, and assessed the relationship between radiotracer uptake and plaque phenotype or predicted cardiovascular risk (ASSIGN score [Assessing Cardiovascular Risk Using SIGN Guidelines to Assign Preventive Treatment]). We also performed micro PET/CT and histological analysis of excised plaque. On histological and micro PET/CT analysis, 18F-fluoride selectively highlighted microcalcification. Carotid 18F-fluoride uptake was increased in clinically adjudicated culprit plaques compared with asymptomatic contralateral plaques (log10standardized uptake valuemean 0.29±0.10 versus 0.23±0.11, P=0.001) and compared with control patients (log10standardized uptake valuemean 0.29±0.10 versus 0.12±0.11, P=0.001). 18F-Fluoride uptake correlated with high-risk plaque features (remodeling index [r=0.53, P=0.003], plaque burden [r=0.51, P=0.004]), and predicted cardiovascular risk [r=0.65, P=0.002]). Carotid 18F-fluorodeoxyglucose uptake appeared to be increased in 7 of 16 culprit plaques, but no overall differences in uptake were observed in culprit versus contralateral plaques or control patients. However, 18F-fluorodeoxyglucose did correlate with predicted cardiovascular risk (r=0.53, P=0.019), but not with plaque phenotype. Conclusions— 18F-Fluoride PET/CT highlights culprit and phenotypically high-risk carotid plaque

  9. Production and test of {sup 18}F samples in the SNICS ion source

    SciTech Connect

    Rehm, K.E.; Paul, M.; Roberts, A.; Nickels, J.

    1995-08-01

    For experiments with {sup 18}F beams the output of the SNICS ion source for fluorine ions was investigated. {sup 18}F, which is a well-studied PET isotope, is generated at the medical cyclotron of the University of Wisconsin. Aqueous [{sup 18}F] fluoride ions are produced via the {sup 18}O(p,n){sup 18}F reaction using a 30-{mu}A, 11.4-MeV proton beam bombarding a 95% enriched [{sup 18}O] water target. In order to minimize the {sup 18}O component of the {sup 18}F material the [{sup 18}F] fluoride must be separated from the [{sup 18}O] water. For this purpose the aqueous [{sup 18}F] fluoride solution ({approximately} 0.5-1 ml) is removed from the production target and placed in a glassy carbon vessel. The vessel is heated to 115{degrees}C with He bubbling through the solution, evaporating the water while the {sup 18}F adheres to the vessel walls. When dry, the vessel is filled with 1 ml {sup 18}O-depleted 99.98% [{sup 16}O] water which is again evaporated. After this step is repeated once more the vessel is filled with 1.5 ml [{sup 16}O] water and 200-300 mole of natural KF as carrier material.

  10. Clinical utility of (18)F-fluoride PET/CT in benign and malignant bone diseases.

    PubMed

    Li, Yuxin; Schiepers, Christiaan; Lake, Ralph; Dadparvar, Simin; Berenji, Gholam R

    2012-01-01

    (18)F labeled sodium fluoride is a positron-emitting, bone seeking agent with more favorable skeletal kinetics than conventional phosphate and diphosphonate compounds. With the expanding clinical usage of PET/CT, there is renewed interest in using (18)F-fluoride PET/CT for imaging bone diseases. Growing evidence indicates that (18)F fluoride PET/CT offers increased sensitivity, specificity, and diagnostic accuracy in evaluating metastatic bone disease compared to (99m)Tc based bone scintigraphy. National Oncologic PET Registry (NOPR) has expanded coverage for (18)F sodium fluoride PET scans since February 2011 for the evaluation of osseous metastatic disease. In this article, we reviewed the pharmacological characteristics of sodium fluoride, as well as the clinical utility of PET/CT using (18)F-fluoride in both benign and malignant bone disorders.

  11. Mild and regiospecific synthesis of 18F-labelled vinyl fluoride using [18F]fluorine reacted with silane.

    PubMed

    Di Raddo, P; Diksic, M

    1985-12-01

    A labelled vinyl fluoride of biological interest was prepared in good radiochemical yield by direct fluorination of the corresponding silane. The synthesis of 18F-labelled 4-fluoroantipyrine, a cerebral blood flow tracer, involved the reaction of 4-(trimethylsilyl) antipyrine with [18F]F2 (0.5% fluorine in neon) or 5% F2 in nitrogen in freon-11 as solvent. A radiochemical (chemical) yield of about 18% (42%) was obtained in a 25-min synthesis. The radiochemical and chemical purity of the final products was 99% after purification by HPLC.

  12. Magnetic Droplet Microfluidics as a Platform for the Concentration of [18F]Fluoride and Radiosynthesis of Sulfonyl [18F]Fluoride.

    PubMed

    Fiel, Somewhere A; Yang, Hua; Schaffer, Paul; Weng, Samuel; Inkster, James A H; Wong, Michael C K; Li, Paul C H

    2015-06-17

    The radioisotope 18F is often considered the best choice for positron emission tomography (PET) owing to its desirable chemical and radiochemical properties. However, nucleophilic 18F-fluorination of large, water-soluble biomolecules, based on C-F bond formation, has traditionally been difficult. Thus, several aqueous fluorination approaches that offer significant versatility in radiopharmaceutical synthesis with sensitive targeting vectors have been developed. Furthermore, because 18F decays rapidly, production of these 18F-labeled compounds requires an automated process to reduce production time, reduce radiation exposure, and minimize losses due to the transfer of reagents during tracer synthesis. Herein, we report the use of magnetic droplet microfluidics (MDM) as a means to concentrate [18F]fluoride from the cyclotron target solution, followed by the synthesis of an 18F-labeled compound on a microfluidic platform. Using this method, we have demonstrated 18F preconcentration in a small-volume droplet through the use of anion exchanging magnetic particles. By using MDM, the preconcentration step took approximately 5 min, and the [18F]fluoride solution was preconcentrated by 15-fold. After the preconcentration step, an 18F-labeling reaction was performed on the MDM platform using the S-F bond formation in aqueous conditions to produce an arylsulfonyl [18F]fluoride compound which can be used as a prosthetic group to label PET targeting ligands. The high radiochemical purity of 95±1% was comparable to the 96% previously reported using a conventional method. In addition, when MDM was used, the total synthesis time was improved to 15 min with lower reagent volumes (50-60 μL) used.

  13. No-carrier-added (NCA) aryl [{sup 18}F]fluorides via the nucleophilic aromatic substitution of electron rich aromatic rings

    SciTech Connect

    Ding, Yu-Shin; Fowler, J.S.; Wolf, A.P.

    1991-12-31

    A method for synthesizing no-carrier-added (NCA) aryl [{sup 18}F] fluoride substituted aromatic aldehyde compositions bearing an electron donating group is described. The method includes the step of reacting aromatic nitro aldehydes having a suitably protected hydroxyl substituent on an electron rich ring. The reaction is carried out by nucleophilic aromatic substitution with a no-carrier-added (NCA) [{sup 18}F]fluoride ion. The method can be used to synthesize various no-carrier-added aryl [{sup 18}F]fluoride compositions, including 6-[{sup 18}F]fluoro-L-DOPA, 2-[{sup 18}F]fluorotyrosine, 6-[{sup 18}F]fluoronorepinephrine, and 6-[{sup 18}F]fluorodopamine. In those instances when a racemic mixture of enantiomers is produced by the present invention, such as in the synthesis of 6-[{sup 18}F]fluoronorepinephrine, a preferred method also includes resolution of the racemic mixture on a chiral HPLC column. This procedure results in a high yield of enantiomerically pure [{sup 18}F] labeled isomers, for example [-]-6-[{sup 18}F]fluoronorepinephrine and [+]-6-[{sup 18}F]fluoronorepinephrine.

  14. Feasibility of 18F-sodium fluoride PET/CT for imaging of atherosclerotic plaque.

    PubMed

    Derlin, Thorsten; Richter, Ulrich; Bannas, Peter; Begemann, Philipp; Buchert, Ralph; Mester, Janos; Klutmann, Susanne

    2010-06-01

    The aim of this study was to examine the prevalence, distribution, and topographic relationship of vascular (18)F-sodium fluoride uptake and arterial calcification in major arteries. Image data obtained from 75 patients undergoing whole-body (18)F-sodium fluoride PET/CT were evaluated retrospectively. Arterial radiotracer uptake and calcification were analyzed qualitatively and semiquantitatively. (18)F-sodium fluoride uptake was observed at 254 sites in 57 (76%) of the 75 study patients, and calcification was observed at 1,930 sites in 63 (84%) of the patients. Colocalization of radiotracer accumulation and calcification could be observed in 223 areas of uptake (88%). However, only 12% of all arterial calcification sites showed increased radiotracer uptake. Our data indicate the feasibility of (18)F-sodium fluoride PET/CT for the imaging of mineral deposition in arterial wall alterations. (18)F-sodium fluoride PET/CT may provide relevant information about the morphologic and functional properties of calcified plaque.

  15. (18)F-fluoride PET imaging in a nude rat model of bone metastasis from breast cancer: Comparison with (18)F-FDG and bioluminescence imaging.

    PubMed

    Kang, Won Jun; Song, Eun Hye; Park, Jun Young; Park, Young Jin; Cho, Arthur; Song, Ho-Taek

    2015-09-01

    Clinically-relevant animal models and appropriate imaging diagnostic tools are essential to study cancer and develop novel therapeutics. We evaluated a model of bone metastasis in nude rats by micro-PET and bioluminescence imaging. A bone metastasis model was produced by intracardiac injection of osteotropic MDA-MB-231Bo-Luc human breast cancer cells into nude rats. Bioluminescence imaging and micro-PET scans using (18)F-FDG and (18)F-fluoride were acquired serially for 5 weeks. We correlated bioluminescence imaging, (18)F-FDG and (18)F-fluoride PET images, and histological slides. Multiple bone metastases were successfully evaluated by bioluminescence imaging and (18)F-FDG and (18)F-fluoride PET scans. Bioluminescence photon flux increased exponentially on weekly follow-up. (18)F-FDG PET revealed increased FDG uptake at the spine and bilaterally in the hind legs in week 2 images, and showed a progressive pattern up to 4 weeks that correlated with bioluminescence imaging. (18)F-fluoride PET showed minimal abnormal findings in week 2 images, but it showed an irregular pattern at the spine from week 3 or 4 images. On quantitative analysis with standardized uptake values, a pattern of gradual increase was observed from week 2 to week 4 in both (18)F-FDG PET and fluoride PET. Histopathological examination confirmed the formation of osteolytic metastasis and necrosis of the distal femur, which appeared as a photon defect on PET scans. Developing bone metastasis from breast cancer in a nude rat model was successfully evaluated with an animal PET imaging system and bioluminescence imaging. This nude rat model of bone metastasis, which can be evaluated by PET imaging, may be a valuable tool for evaluating early responses to novel therapeutics. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Quantification of 18F-Fluoride Kinetics: Evaluation of Simplified Methods.

    PubMed

    Raijmakers, Pieter; Temmerman, Olivier P P; Saridin, Carrol P; Heyligers, Ide C; Becking, Alfred G; van Lingen, Arthur; Lammertsma, Adriaan A

    2014-07-01

    (18)F-fluoride PET is a promising noninvasive method for measuring bone metabolism and bone blood flow. The purpose of this study was to assess the performance of various clinically useful simplified methods by comparing them with full kinetic analysis. In addition, the validity of deriving bone blood flow from K1 of (18)F-fluoride was investigated using (15)O-H2O as a reference. Twenty-two adults (mean age ± SD, 44.8 ± 25.2 y), including 16 patients scheduled for bone surgery and 6 healthy volunteers, were studied. All patients underwent dynamic (15)O-H2O and (18)F-fluoride scans before surgery. Ten of these patients had serial PET measurements before and at 2 time points after local bone surgery. During all PET scans, arterial blood was monitored continuously. (18)F-fluoride data were analyzed using nonlinear regression (NLR) and several simplified methods (Patlak and standardized uptake value [SUV]). SUV was evaluated for different time intervals after injection and after normalizing to body weight, lean body mass, and body surface area, and simplified measurements were compared with NLR results. In addition, changes in SUV and Patlak-derived fluoride influx rate (Ki) after surgery were compared with corresponding changes in NLR-derived Ki. Finally, (18)F-fluoride K1 was compared with bone blood flow derived from (15)O-H2O data, using the standard single-tissue-compartment model. K1 of (18)F-fluoride correlated with measured blood flow, but the correlation coefficient was relatively low (r = 0.35, P < 0.001). NLR resulted in a mean Ki of 0.0160 ± 0.0122, whereas Patlak analysis, for the interval 10-60 min after injection, resulted in an almost-identical mean Ki of 0.0161 ± 0.0117. The Patlak-derived Ki, for 10-60 min after injection, showed a high correlation with the NLR-derived Ki (r = 0.976). The highest correlation between Ki and lean body mass-normalized SUV was found for the interval 50-60 min (r = 0.958). Finally, changes in SUV correlated

  17. (18)F-fluoride PET for monitoring therapeutic response in Paget's disease of bone.

    PubMed

    Installé, Johanne; Nzeusseu, Adrien; Bol, Anne; Depresseux, Geneviève; Devogelaer, Jean-Pierre; Lonneux, Max

    2005-10-01

    A prospective study was undertaken to evaluate PET with (18)F-fluoride for monitoring the response to bisphosphonates in Paget's disease of bones. Fourteen patients with a monostotic (n = 9) or a polyostotic form (n = 5) of Paget's disease were scanned at baseline and at 1 and 6 mo after the beginning of treatment. Dynamic acquisition and arterial blood sampling were used to calculate the influx constant Ki (by both the Patlak [Ki-PAT] method and the nonlinear regression [Ki-NLR] method). Kinetic modeling was compared with maximal standardized uptake values (SUV(max)) and biochemical markers of bone remodeling. Baseline uptake of (18)F-fluoride by pagetic bones was significantly higher than in normal bones (P < 0.05). One month after the start of treatment, SUV(max), Ki-PAT, Ki-NLR, and K(1) (the unidirectional clearance of fluoride from plasma to the whole of the bone tissue) decreased significantly by 27.8%, 27.9%, 27.5%, and 23.6%, respectively. Biochemical markers were already normalized in 6 of 9 patients with monostotic disease, although all had high (18)F-fluoride uptake values. Six months after the start of treatment, (18)F-fluoride uptake further diminished by 22.3%-25.6%. Biochemical markers were normal in all but 2 patients, although 10 of 14 patients still showed high (18)F-fluoride uptake. One patient did not respond to treatment and maintained high uptake of (18)F-fluoride throughout the study. SUV(max) correlated with both Ki-PAT and Ki-NLR at baseline, 1 mo, and 6 mo (P < 0.05). Moreover, the change of SUV(max) between baseline and 1 mo, as well as between baseline and 6 mo, also correlated with the change of Ki-PAT and Ki-NLR (P < 0.05). Our results show that (18)F-fluoride PET can be used to noninvasively and accurately monitor the efficacy of treatment with bisphosphonates in Paget's disease of bones. SUV(max) correlates with Ki-PAT and Ki-NLR and, interestingly, varies in the same manner as kinetic indices. Therefore, the use of SUV(max) could

  18. Sodium 18F-Fluoride PET/CT of Bone, Joint and Other Disorders

    PubMed Central

    Jadvar, Hossein; Desai, Bhushan; Conti, Peter S.

    2014-01-01

    The use of 18F-sodium fluoride (18F-NaF) with positron emission tomography-computed tomography (PET/CT) is increasing. This resurgence of an old tracer has been fueled by several factors including superior diagnostic performance over standard 99mTc-based bone scintigraphy, growth in the availability of PET/CT imaging systems, increase in the number of regional commercial distribution centers for PET radiotracers, the recent concerns about potential chronic shortages with 99mTc based radiotracers, and the recent decision by the Centers for Medicare and Medicaid Services to reimburse for 18F-NaF PET/CT for evaluation of patients with known or suspected bone metastases through the National Oncologic PET Registry. The major goal of this article is to review the current evidence on the diagnostic utility of 18F-NaF in the imaging assessment of bone and joint in a variety of clinical conditions. PMID:25475379

  19. Prediction of femoral head collapse in osteonecrosis using 18F-fluoride positron emission tomography.

    PubMed

    Kubota, So; Inaba, Yutaka; Kobayashi, Naomi; Tateishi, Ukihide; Ike, Hiroyuki; Inoue, Tomio; Saito, Tomoyuki

    2015-06-01

    We investigated the usefulness of (18)F-fluoride PET as a predictor of femoral head collapse in patients with osteonecrosis (ON) before radiographic changes occur. Sixty-six hips of 42 patients diagnosed with ON of the femoral head were included in this study. We evaluated the relationship between the maximum standardized uptake value (SUV(max)) in (18)F-fluoride PET and the Ficat classification. We evaluated the relationship between SUV(max) and the presence of femoral head collapse on plain radiography at 12 months after (18)F-fluoride PET in 23 hips of 18 patients with Ficat classification stage 1 or 2. A receiver operating characteristic analysis was carried out to calculate the cut-off SUVmax for the prediction of femoral head collapse. We analyzed the relationship between SUV(max) and femoral head collapse on plain radiography in the 23 hips using a logistic regression model. SUV(max) increased according to the progression of the Ficat classification stage. The mean SUV(max) was 12.3±5.9 in the collapse group and 4.9±1.3 in the noncollapse group (P<0.01). The cut-off SUV(max) of 6.45 (sensitivity: 0.80, specificity: 0.92) was used for the prediction of femoral head collapse. In the univariate analysis, SUV(max), type classification, and ring sign were related significantly to femoral head collapse. We showed that the quantitative assessment of SUV(max) in (18)F-fluoride PET was useful to predict femoral head collapse in ON. (18)F-Fluoride PET might reflect accelerated bone metabolism because of microcollapse of the femoral head, which is undetectable on plain radiography.

  20. Identifying active vascular microcalcification by 18F-sodium fluoride positron emission tomography

    PubMed Central

    Irkle, Agnese; Vesey, Alex T.; Lewis, David Y.; Skepper, Jeremy N.; Bird, Joseph L. E.; Dweck, Marc R.; Joshi, Francis R.; Gallagher, Ferdia A.; Warburton, Elizabeth A.; Bennett, Martin R.; Brindle, Kevin M.; Newby, David E.; Rudd, James H.; Davenport, Anthony P.

    2015-01-01

    Vascular calcification is a complex biological process that is a hallmark of atherosclerosis. While macrocalcification confers plaque stability, microcalcification is a key feature of high-risk atheroma and is associated with increased morbidity and mortality. Positron emission tomography and X-ray computed tomography (PET/CT) imaging of atherosclerosis using 18F-sodium fluoride (18F-NaF) has the potential to identify pathologically high-risk nascent microcalcification. However, the precise molecular mechanism of 18F-NaF vascular uptake is still unknown. Here we use electron microscopy, autoradiography, histology and preclinical and clinical PET/CT to analyse 18F-NaF binding. We show that 18F-NaF adsorbs to calcified deposits within plaque with high affinity and is selective and specific. 18F-NaF PET/CT imaging can distinguish between areas of macro- and microcalcification. This is the only currently available clinical imaging platform that can non-invasively detect microcalcification in active unstable atherosclerosis. The use of 18F-NaF may foster new approaches to developing treatments for vascular calcification. PMID:26151378

  1. (18)F-Fluoride and (18)F-Fluorodeoxyglucose Positron Emission Tomography After Transient Ischemic Attack or Minor Ischemic Stroke: Case-Control Study.

    PubMed

    Vesey, Alex T; Jenkins, William S A; Irkle, Agnese; Moss, Alastair; Sng, Greg; Forsythe, Rachael O; Clark, Tim; Roberts, Gemma; Fletcher, Alison; Lucatelli, Christophe; Rudd, James H F; Davenport, Anthony P; Mills, Nicholas L; Al-Shahi Salman, Rustam; Dennis, Martin; Whiteley, William N; van Beek, Edwin J R; Dweck, Marc R; Newby, David E

    2017-03-01

    Combined positron emission tomography (PET) and computed tomography (CT) can assess both anatomy and biology of carotid atherosclerosis. We sought to assess whether (18)F-fluoride or (18)F-fluorodeoxyglucose can identify culprit and high-risk carotid plaque. We performed (18)F-fluoride and (18)F-fluorodeoxyglucose PET/CT in 26 patients after recent transient ischemic attack or minor ischemic stroke: 18 patients with culprit carotid stenosis awaiting carotid endarterectomy and 8 controls without culprit carotid atheroma. We compared standardized uptake values in the clinically adjudicated culprit to the contralateral asymptomatic artery, and assessed the relationship between radiotracer uptake and plaque phenotype or predicted cardiovascular risk (ASSIGN score [Assessing Cardiovascular Risk Using SIGN Guidelines to Assign Preventive Treatment]). We also performed micro PET/CT and histological analysis of excised plaque. On histological and micro PET/CT analysis, (18)F-fluoride selectively highlighted microcalcification. Carotid (18)F-fluoride uptake was increased in clinically adjudicated culprit plaques compared with asymptomatic contralateral plaques (log10standardized uptake valuemean 0.29±0.10 versus 0.23±0.11, P=0.001) and compared with control patients (log10standardized uptake valuemean 0.29±0.10 versus 0.12±0.11, P=0.001). (18)F-Fluoride uptake correlated with high-risk plaque features (remodeling index [r=0.53, P=0.003], plaque burden [r=0.51, P=0.004]), and predicted cardiovascular risk [r=0.65, P=0.002]). Carotid (18)F-fluorodeoxyglucose uptake appeared to be increased in 7 of 16 culprit plaques, but no overall differences in uptake were observed in culprit versus contralateral plaques or control patients. However, (18)F-fluorodeoxyglucose did correlate with predicted cardiovascular risk (r=0.53, P=0.019), but not with plaque phenotype. (18)F-Fluoride PET/CT highlights culprit and phenotypically high-risk carotid plaque. This has the potential to

  2. Reusable electrochemical cell for rapid separation of [18F]fluoride from [18O]water for flow-through synthesis of 18F-labeled tracers

    PubMed Central

    Sadeghi, Saman; Liang, Vincent; Cheung, Shilin; Woo, Suh; Wu, Curtis; Ly, Jimmy; Deng, Yuliang; Eddings, Mark; van Dam, R. Michael

    2015-01-01

    A brass-platinum electrochemical micro flow cell was developed to extract [18F]fluoride from an aqueous solution and release it into an organic based solution, suitable for subsequent radio-synthesis, in a fast and reliable manner. This cell does not suffer electrode erosion and is thus reusable while operating faster by enabling increased voltages. By optimizing temperature, trapping and release potentials, flow rates, and electrode materials, an overall [18F]fluoride trapping and release efficiency of 84±5% (n=7) was achieved. X-ray photoelectron spectroscopy (XPS) was used to analyze electrode surfaces of various metal-metal systems and the findings were correlated with the performance of the electrochemical cell. To demonstrate the reactivity of the released [18F]fluoride, the cell was coupled to a flow-through reactor and automated synthesis of [18F]FDG with a repeatable decay-corrected yield of 56±4% (n=4) was completed in <15 min. A multi-human dose of 5.92 GBq [18F]FDG was also demonstrated. PMID:23474380

  3. Retention of [(18)F]fluoride on reversed phase HPLC columns.

    PubMed

    Ory, Dieter; Van den Brande, Jeroen; de Groot, Tjibbe; Serdons, Kim; Bex, Marva; Declercq, Lieven; Cleeren, Frederik; Ooms, Maarten; Van Laere, Koen; Verbruggen, Alfons; Bormans, Guy

    2015-01-01

    As [(18)F]fluoride is a starting reagent in the radiosynthesis of most fluorine-18 labeled positron emission tomography (PET) tracers, its chromatographic behavior on reversed phase (RP) HPLC columns is important for the purification performance and accuracy of RP HPLC quality control methods. We have investigated the chromatographic behavior and recovery of [(18)F]fluoride as a function of the type and brand of RP HPLC column, the pH and the composition of the mobile phase. Elution and elution profile of [(18)F]fluoride from six RP-HPLC columns (Waters XBridge C18 3 mm × 100 mm 3.5 μm; Grace Platinum EPS C18 4.6 mm × 100 mm, 3 μm; Waters XTerra C18 4.6 mm × 250 mm, 5 μm; Phenomenex C18 4.6 mm × 150 mm, 5 μm; Hamilton PRP-1 column 4.1 mm × 150 mm, 5 μm; Merck KGaA Chromolith Performance C18 3 mm × 100 mm) eluted with mobile phase composed of phosphate or acetate buffers (pH 2, 3, 4, 5, 7.3 and 9) and acetonitrile or ethanol as organic modifier were characterized. The elution profile was determined by on-line radioactivity measurement in the column eluate and recovery was calculated by comparison of radioactivity eluted with the HPLC column present or absent in the chromatographic flow path. Interestingly, [(18)F]fluoride recovery increased with increasing pH. At pH 3 all packed silica-based columns showed significant retention of fluorine-18, whereas almost no retention was observed on a polymeric PRP-1 column. However at pH 5, [(18)F]fluoride recovery was above 90% for each tested column. In addition, small differences were observed when changing the composition of the mobile phase. We therefore recommend to use a mobile phase with pH > 5 for silica based C18 columns for both quality control and semi-preparative HPLC of fluorine-18 labeled PET radiopharmaceuticals. If required a lower pH can be used in combination with a polymer based HPLC column.

  4. 18F-Labeled Silicon-Based Fluoride Acceptors: Potential Opportunities for Novel Positron Emitting Radiopharmaceuticals

    PubMed Central

    Bernard-Gauthier, Vadim; Wängler, Carmen; Wängler, Bjoern; Schirrmacher, Ralf

    2014-01-01

    Background. Over the recent years, radiopharmaceutical chemistry has experienced a wide variety of innovative pushes towards finding both novel and unconventional radiochemical methods to introduce fluorine-18 into radiotracers for positron emission tomography (PET). These “nonclassical” labeling methodologies based on silicon-, boron-, and aluminium-18F chemistry deviate from commonplace bonding of an [18F]fluorine atom (18F) to either an aliphatic or aromatic carbon atom. One method in particular, the silicon-fluoride-acceptor isotopic exchange (SiFA-IE) approach, invalidates a dogma in radiochemistry that has been widely accepted for many years: the inability to obtain radiopharmaceuticals of high specific activity (SA) via simple IE. Methodology. The most advantageous feature of IE labeling in general is that labeling precursor and labeled radiotracer are chemically identical, eliminating the need to separate the radiotracer from its precursor. SiFA-IE chemistry proceeds in dipolar aprotic solvents at room temperature and below, entirely avoiding the formation of radioactive side products during the IE. Scope of Review. A great plethora of different SiFA species have been reported in the literature ranging from small prosthetic groups and other compounds of low molecular weight to labeled peptides and most recently affibody molecules. Conclusions. The literature over the last years (from 2006 to 2014) shows unambiguously that SiFA-IE and other silicon-based fluoride acceptor strategies relying on 18F− leaving group substitutions have the potential to become a valuable addition to radiochemistry. PMID:25157357

  5. 18F-Fluoride PET/CT allows detection of hyperostosis and osseous involvement in meningioma: initial experience.

    PubMed

    Tateishi, Ukihide; Tateishi, Kensuke; Shizukuishi, Kazuya; Shishikura, Ayako; Murata, Hidetoshi; Inoue, Tomio; Kawahara, Nobutaka

    2013-03-01

    The present study was conducted to assess the diagnostic performance of (18)F-fluoride PET/CT in evaluating hyperostosis and osseous involvement in patients with meningioma. Thirty-four patients with meningioma (mean age, 61 years) underwent (18)F-fluoride PET/CT before surgery. In 24 patients (71%), (18)F-FDG PET/CT was also given before surgery, and the results were compared. The images were reviewed by 2 board-certified nuclear medicine specialists who were unaware of any clinical information and a consensus was reached. Uptake patterns and measurements of tracers were compared with pathological findings from resected specimens, with hyperostosis and osseous involvement as the reference standard. There were 27 grade I tumors (79%) and 7 grade II tumors (21%). The primary tumor focus was identified in each patient using both (18)`F-fluoride PET/CT and (18)F-FDG PET/CT, but there were no significant correlations in the degree of uptake between the 2 tracers. The SUV(max), SUV(max) corrected for lean body mass (SUL(max)), and tumor metabolic volume (TMV) for (18)F-fluoride and (18)F-FDG were greater in grade II tumors than in grade I tumors. Hyperostosis and osseous involvement was identified in 12 tumors (38%). The SUV(max), SUL(max), and TMV of tumors visualized with (18)F-fluoride PET/CT were greater in tumors with hyperostosis and osseous involvement than in those without (P = 0.005, P = 0.003, and P = 0.006, respectively). In contrast, the SUV(max), SUL(max), and TMV of tumors visualized with (18)F-FDG PET/CT were similar regardless of hyperostosis or osseous involvement. (18)F-fluoride PET/CT may improve detection of hyperostosis and osseous involvement in patients with meningioma.

  6. Correlation between thoracic aorta 18F-natrium fluoride uptake and cardiovascular risk

    PubMed Central

    Fiz, Francesco; Morbelli, Silvia; Bauckneht, Matteo; Piccardo, Arnoldo; Ferrarazzo, Giulia; Nieri, Alberto; Artom, Nathan; Cabria, Manlio; Marini, Cecilia; Canepa, Marco; Sambuceti, Gianmario

    2016-01-01

    AIM: To investigating the relationship between thoracic and cardiac 18F-Natrium-Fluoride (18F-NaF) uptake, as a marker of ongoing calcification and cardiovascular risk factors. METHODS: Seventy-eight patients (44 females, mean age 63, range 44-83) underwent whole body 18F-NaF positron emission tomography/computed tomography. Cardiovascular risk (CVR) was used to divide these patients in three categories: Low (LR), medium (MR) and high risk (HR). 18F-NaF uptake was measured by manually drawing volumes of interest on the ascending aorta, on the aortic arch, on the descending aorta and on the myocardium; average standardized uptake value was normalized for blood-pool, to obtain target-to-background ratio (TBR). Values from the three aortic segments were then averaged to obtain an index of the whole thoracic aorta. RESULTS: A significant difference in whole thoracic aorta TBR was detected between HR and LR (1.84 ± 0.76 vs 1.07 ± 0.3, P < 0.001), but also between MR and HR-LR (1.4 ± 0.4, P < 0.02 and P < 0.01, respectively). Significance of this TBR stratification strongly varied among thoracic aorta subsegments and the lowest P values were reached in the descending aorta (P < 0.01). Myocardial uptake provided an effective CVR classes stratification (P < 0.001).Correlation between TBR and CVR was appreciable when the whole thoracic aorta was considered (R = 0.67), but it peaked when correlating the descending thoracic segment (R = 0.75), in comparison with the aortic arch and the ascending segment (R = 0.55 and 0.53, respectively). CONCLUSION: Fluoride uptake within the thoracic aorta wall effectively depicts patients’ risk class and correlates with cardiovascular risk. Descending aorta is the most effective in CVR determination. PMID:26834946

  7. Correlation between mechanical stress by finite element analysis and 18F-fluoride PET uptake in hip osteoarthritis patients.

    PubMed

    Hirata, Yasuhide; Inaba, Yutaka; Kobayashi, Naomi; Ike, Hiroyuki; Yukizawa, Yohei; Fujimaki, Hiroshi; Tezuka, Taro; Tateishi, Ukihide; Inoue, Tomio; Saito, Tomoyuki

    2015-01-01

    18F-fluoride positron emission tomography (18F-fluoride PET) is a functional imaging modality used primarily to detect increased bone metabolism. Increased 18F-fluoride PET uptake suggests an association between increased bone metabolism and load stress at the subchondral level. This study therefore examined the relationship between equivalent stress distribution calculated by finite element analysis and 18F-fluoride PET uptake in patients with hip osteoarthritis. The study examined 34 hips of 17 patients who presented to our clinic with hip pain, and were diagnosed with osteoarthritis or pre-osteoarthritis. The hips with trauma, infection, or bone metastasis of cancer were excluded. Three-dimensional models of each hip were created from computed tomography data to calculate the maximum equivalent stress by finite element analysis, which was compared with the maximum standardized uptake value (SUVmax) examined by 18F-fluoride PET. The SUVmax and equivalent stress were correlated (Spearman's rank correlation coefficient ρ=0.752), and higher equivalent stress values were noted in higher SUVmax patients. The correlation between SUVmax and maximum equivalent stress in osteoarthritic hips suggests the possibility that 18F-fluoride PET detect increased bone metabolism at sites of stress concentration. This study demonstrates the correlation between mechanical stress and bone remodeling acceleration in hip osteoarthritis.

  8. Demons versus level-set motion registration for coronary 18F-sodium fluoride PET

    NASA Astrophysics Data System (ADS)

    Rubeaux, Mathieu; Joshi, Nikhil; Dweck, Marc R.; Fletcher, Alison; Motwani, Manish; Thomson, Louise E.; Germano, Guido; Dey, Damini; Berman, Daniel S.; Newby, David E.; Slomka, Piotr J.

    2016-03-01

    Ruptured coronary atherosclerotic plaques commonly cause acute myocardial infarction. It has been recently shown that active microcalcification in the coronary arteries, one of the features that characterizes vulnerable plaques at risk of rupture, can be imaged using cardiac gated 18F-sodium fluoride (18F-NaF) PET. We have shown in previous work that a motion correction technique applied to cardiac-gated 18F-NaF PET images can enhance image quality and improve uptake estimates. In this study, we further investigated the applicability of different algorithms for registration of the coronary artery PET images. In particular, we aimed to compare demons vs. level-set nonlinear registration techniques applied for the correction of cardiac motion in coronary 18F-NaF PET. To this end, fifteen patients underwent 18F-NaF PET and prospective coronary CT angiography (CCTA). PET data were reconstructed in 10 ECG gated bins; subsequently these gated bins were registered using demons and level-set methods guided by the extracted coronary arteries from CCTA, to eliminate the effect of cardiac motion on PET images. Noise levels, target-to-background ratios (TBR) and global motion were compared to assess image quality. Compared to the reference standard of using only diastolic PET image (25% of the counts from PET acquisition), cardiac motion registration using either level-set or demons techniques almost halved image noise due to the use of counts from the full PET acquisition and increased TBR difference between 18F-NaF positive and negative lesions. The demons method produces smoother deformation fields, exhibiting no singularities (which reflects how physically plausible the registration deformation is), as compared to the level-set method, which presents between 4 and 8% of singularities, depending on the coronary artery considered. In conclusion, the demons method produces smoother motion fields as compared to the level-set method, with a motion that is physiologically

  9. Demons versus Level-Set motion registration for coronary 18F-sodium fluoride PET

    PubMed Central

    Rubeaux, Mathieu; Joshi, Nikhil; Dweck, Marc R.; Fletcher, Alison; Motwani, Manish; Thomson, Louise E.; Germano, Guido; Dey, Damini; Berman, Daniel S.; Newby, David E.; Slomka, Piotr J.

    2016-01-01

    Ruptured coronary atherosclerotic plaques commonly cause acute myocardial infarction. It has been recently shown that active microcalcification in the coronary arteries, one of the features that characterizes vulnerable plaques at risk of rupture, can be imaged using cardiac gated 18F-sodium fluoride (18F-NaF) PET. We have shown in previous work that a motion correction technique applied to cardiac-gated 18F-NaF PET images can enhance image quality and improve uptake estimates. In this study, we further investigated the applicability of different algorithms for registration of the coronary artery PET images. In particular, we aimed to compare demons vs. level-set nonlinear registration techniques applied for the correction of cardiac motion in coronary 18F-NaF PET. To this end, fifteen patients underwent 18F-NaF PET and prospective coronary CT angiography (CCTA). PET data were reconstructed in 10 ECG gated bins; subsequently these gated bins were registered using demons and level-set methods guided by the extracted coronary arteries from CCTA, to eliminate the effect of cardiac motion on PET images. Noise levels, target-to-background ratios (TBR) and global motion were compared to assess image quality. Compared to the reference standard of using only diastolic PET image (25% of the counts from PET acquisition), cardiac motion registration using either level-set or demons techniques almost halved image noise due to the use of counts from the full PET acquisition and increased TBR difference between 18F-NaF positive and negative lesions. The demons method produces smoother deformation fields, exhibiting no singularities (which reflects how physically plausible the registration deformation is), as compared to the level-set method, which presents between 4 and 8% of singularities, depending on the coronary artery considered. In conclusion, the demons method produces smoother motion fields as compared to the level-set method, with a motion that is physiologically

  10. Demons versus Level-Set motion registration for coronary (18)F-sodium fluoride PET.

    PubMed

    Rubeaux, Mathieu; Joshi, Nikhil; Dweck, Marc R; Fletcher, Alison; Motwani, Manish; Thomson, Louise E; Germano, Guido; Dey, Damini; Berman, Daniel S; Newby, David E; Slomka, Piotr J

    2016-02-27

    Ruptured coronary atherosclerotic plaques commonly cause acute myocardial infarction. It has been recently shown that active microcalcification in the coronary arteries, one of the features that characterizes vulnerable plaques at risk of rupture, can be imaged using cardiac gated (18)F-sodium fluoride ((18)F-NaF) PET. We have shown in previous work that a motion correction technique applied to cardiac-gated (18)F-NaF PET images can enhance image quality and improve uptake estimates. In this study, we further investigated the applicability of different algorithms for registration of the coronary artery PET images. In particular, we aimed to compare demons vs. level-set nonlinear registration techniques applied for the correction of cardiac motion in coronary (18)F-NaF PET. To this end, fifteen patients underwent (18)F-NaF PET and prospective coronary CT angiography (CCTA). PET data were reconstructed in 10 ECG gated bins; subsequently these gated bins were registered using demons and level-set methods guided by the extracted coronary arteries from CCTA, to eliminate the effect of cardiac motion on PET images. Noise levels, target-to-background ratios (TBR) and global motion were compared to assess image quality. Compared to the reference standard of using only diastolic PET image (25% of the counts from PET acquisition), cardiac motion registration using either level-set or demons techniques almost halved image noise due to the use of counts from the full PET acquisition and increased TBR difference between (18)F-NaF positive and negative lesions. The demons method produces smoother deformation fields, exhibiting no singularities (which reflects how physically plausible the registration deformation is), as compared to the level-set method, which presents between 4 and 8% of singularities, depending on the coronary artery considered. In conclusion, the demons method produces smoother motion fields as compared to the level-set method, with a motion that is

  11. 18F-sodium fluoride uptake is a marker of active calcification and disease progression in patients with aortic stenosis.

    PubMed

    Dweck, Marc R; Jenkins, William S A; Vesey, Alex T; Pringle, Mark A H; Chin, Calvin W L; Malley, Tamir S; Cowie, William J A; Tsampasian, Vasiliki; Richardson, Hamish; Fletcher, Alison; Wallace, William A; Pessotto, Renzo; van Beek, Edwin J R; Boon, Nicholas A; Rudd, James H F; Newby, David E

    2014-03-01

    18F-Sodium fluoride (18F-NaF) and 18F-fluorodeoxyglucose (18F-FDG) are promising novel biomarkers of disease activity in aortic stenosis. We compared 18F-NaF and 18F-FDG uptake with histological characterization of the aortic valve and assessed whether they predicted disease progression. Thirty patients with aortic stenosis underwent combined positron emission and computed tomography using 18F-NaF and 18F-FDG radiotracers. In 12 patients undergoing aortic valve replacement surgery (10 for each tracer), radiotracer uptake (mean tissue/ =0.65; P=0.04) and osteocalcin (r=0.68; P=0.03) immunohistochemistry. There was no significant correlation between 18F-FDG uptake and CD68 staining (r=-0.43; P=0.22). After 1 year, aortic valve calcification increased from 314 (193-540) to 365 (207-934) AU (P<0.01). Baseline 18F-NaF uptake correlated closely with the change in calcium score (r=0.66; P<0.01), and this improved further (r=0.75; P<0.01) when 18F-NaF uptake overlying computed tomography-defined macrocalcification was excluded. No significant correlation was noted between valvular 18F-FDG uptake and change in calcium score (r=-0.11; P=0.66). 18F-NaF uptake identifies active tissue calcification and predicts disease progression in patients with calcific aortic stenosis. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01358513.

  12. Utility of 18F sodium fluoride PET/CT imaging in the evaluation of postoperative pain following surgical spine fusion.

    PubMed

    Pouldar, D; Bakshian, S; Matthews, R; Rao, V; Manzano, M; Dardashti, S

    2017-08-01

    A retrospective case review of patients who underwent 18F sodium fluoride PET/CT imaging of the spine with postoperative pain following vertebral fusion. To determine the benefit of 18F sodium fluoride PET/CT imaging in the diagnosis of persistent pain in the postoperative spine. The diagnosis of pain generators in the postoperative spine has proven to be a diagnostic challenge. The conventional radiologic evaluation of persistent pain after spine surgery with the use of plain radiographs, MRI, and CT can often fall short of diagnosis in the complex patient. 18F sodium fluoride PET/CT imaging is an alternative tool to accurately identify a patient's source of pain in the difficult patient. This retrospective study looked at 25 adult patients who had undergone 18F sodium fluoride PET/CT imaging. All patients had persistent or recurrent back pain over the course of a 15-month period after having undergone spinal fusion surgery. All patients had inconclusive dedicated MRI. The clinical accuracy of PET/CT in identifying the pain generator and contribution to altering the decision making process was compared to the use of CT scan alone. Of the 25 patients studied, 17 patients had increased uptake on the 18F sodium fluoride PET/CT fusion images. There was a high-level correlation of radiotracer uptake to the patients' pain generator. Overall 88% of the studies were considered beneficial with either PET/CT altering the clinical diagnosis and treatment plan of the patient or confirming unnecessary surgery. 18F sodium fluoride PET/CT proves to be a useful tool in the diagnosis of complex spine pathology of the postoperative patients. In varied cases, a high correlation of metabolic activity to the source of the patient's pain was observed.

  13. Optimization and Reproducibility of Aortic Valve 18F-Fluoride Positron Emission Tomography in Patients With Aortic Stenosis

    PubMed Central

    Cartlidge, Timothy R.G.; Jenkins, William S.A.; Adamson, Philip D.; Robson, Phillip; Lucatelli, Christophe; Van Beek, Edwin J.R.; Prendergast, Bernard; Denison, Alan R.; Forsyth, Laura; Rudd, James H.F.; Fayad, Zahi A.; Fletcher, Alison; Tuck, Sharon; Newby, David E.; Dweck, Marc R.

    2016-01-01

    Background— 18F-Fluoride positron emission tomography (PET) and computed tomography (CT) can measure disease activity and progression in aortic stenosis. Our objectives were to optimize the methodology, analysis, and scan–rescan reproducibility of aortic valve 18F-fluoride PET-CT imaging. Methods and Results— Fifteen patients with aortic stenosis underwent repeated 18F-fluoride PET-CT. We compared nongated PET and noncontrast CT, with a modified approach that incorporated contrast CT and ECG-gated PET. We explored a range of image analysis techniques, including estimation of blood-pool activity at differing vascular sites and a most diseased segment approach. Contrast-enhanced ECG-gated PET-CT permitted localization of 18F-fluoride uptake to individual valve leaflets. Uptake was most commonly observed at sites of maximal mechanical stress: the leaflet tips and the commissures. Scan–rescan reproducibility was markedly improved using enhanced analysis techniques leading to a reduction in percentage error from ±63% to ±10% (tissue to background ratio MDS mean of 1.55, bias −0.05, limits of agreement −0·20 to +0·11). Conclusions— Optimized 18F-fluoride PET-CT allows reproducible localization of calcification activity to different regions of the aortic valve leaflet and commonly to areas of increased mechanical stress. This technique holds major promise in improving our understanding of the pathophysiology of aortic stenosis and as a biomarker end point in clinical trials of novel therapies. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT02132026. PMID:27733431

  14. Correlation of inflammation assessed by 18F-FDG PET, active mineral deposition assessed by 18F-fluoride PET, and vascular calcification in atherosclerotic plaque: a dual-tracer PET/CT study.

    PubMed

    Derlin, Thorsten; Tóth, Zoltán; Papp, László; Wisotzki, Christian; Apostolova, Ivayla; Habermann, Christian R; Mester, Janos; Klutmann, Susanne

    2011-07-01

    Formation and progression of atherosclerotic plaque is a dynamic and complex process involving various pathophysiologic steps including inflammation and calcification. The purpose of this study was to compare macrophage activity as determined by (18)F-FDG PET and ongoing mineral deposition as measured by (18)F-sodium fluoride PET in atherosclerotic plaque and to correlate these findings with calcified plaque burden as assessed by CT. Forty-five patients were examined by whole-body (18)F-FDG PET, (18)F-sodium fluoride PET, and CT. Tracer uptake in various arterial segments was analyzed both qualitatively and semiquantitatively by measuring the blood-pool-corrected standardized uptake value (target-to-background ratio [TBR]). The pattern of tracer uptake in atherosclerotic lesions was compared after color-coded multistudy image fusion of PET and CT studies. The Fisher exact test and the Spearman correlation coefficient r(s) were used for statistical analysis of image-based results and cardiovascular risk factors. Intra- and interrater reproducibility were evaluated using the Cohen κ. (18)F-sodium fluoride uptake was observed at 105 sites in 27 (60%) of the 45 study patients, and mean TBR was 2.3 ± 0.7. (18)F-FDG uptake was seen at 124 sites in 34 (75.6%) patients, and mean TBR was 1.5 ± 0.3. Calcified atherosclerotic lesions were observed at 503 sites in 34 (75.6%) patients. Eighty-one (77.1%) of the 105 lesions with marked (18)F-sodium fluoride uptake and only 18 (14.5%) of the 124 lesions with (18)F-FDG accumulation were colocalized with arterial calcification. Coincident uptake of both (18)F-sodium fluoride and (18)F-FDG was observed in only 14 (6.5%) of the 215 arterial lesions with radiotracer accumulation. PET/CT with (18)F-FDG and (18)F-sodium fluoride may allow evaluation of distinct pathophysiologic processes in atherosclerotic lesions and might provide information on the complex interactions involved in formation and progression of atherosclerotic plaque.

  15. Regularized ML reconstruction for time/dose reduction in 18F-fluoride PET/CT studies

    NASA Astrophysics Data System (ADS)

    De Bernardi, Elisabetta; Magnani, Patrizia; Gianolli, Luigi; Carla Gilardi, Maria; Bettinardi, Valentino

    2015-01-01

    We are proposing a regularized reconstruction strategy for the detection of bone lesions in 18F-fluoride whole body PET images obtained with 1 min/bed using the anatomical information provided by co-registered CT images. Bones are recognized on CT images and then transposed into the PET volume framework. During PET reconstruction, two different priors are used for bone and non-bone voxels: the relative difference prior in bone and the P-Gaussian prior in non-bone. After a tuning of the priors’ parameters, the reconstruction strategy has been tested on 6 18F-fluoride PET/CT studies, on a total of 67 lesions. Regularized images provided results comparable to the standard 3 min/bed images, in terms image quality, lesion activity, noise level and noise correlation. The proposed strategy therefore appears to be a useful tool to reduce the acquisition time or the injected dose in 18F-fluoride PET studies.

  16. (18) F-sodium fluoride positron emission tomography of the equine distal limb: Exploratory study in three horses.

    PubMed

    Spriet, M; Espinosa, P; Kyme, A Z; Phillips, K L; Katzman, S A; Galuppo, L D; Stepanov, P; Beylin, D

    2017-07-14

    Positron emission tomography (PET) is a cross-sectional, functional imaging modality that has recently become available to the horse. The use of (18) F-sodium fluoride ((18) F-NaF), a PET bone tracer, has not previously been reported in this species. To assess the feasibility of (18) F-NaF PET in the equine distal limb and explore possible applications in the horse in comparison with other imaging modalities. Exploratory descriptive study involving three research horses. Horses were placed under general anaesthesia prior to intravenous (i.v.) administration of 1.5 MBq/kg of (18) F-NaF. Positron emission tomography imaging of both front feet and fetlocks was performed using a portable scanner. Computed tomography (CT) of the distal limb was performed under a separate anaesthetic episode. Bone scintigraphy and magnetic resonance imaging (MRI) were subsequently performed under standing sedation. Images obtained from PET and other imaging modalities were independently assessed and the results correlated. Positron emission tomography images were obtained without complication. The radiation exposure rate was similar to equine bone scintigraphy. Positron emission tomography detected focal (18) F-NaF uptake in areas where other imaging modalities did not identify any abnormalities. This included sites of ligamentous attachment, subchondral compact bone plate and the flexor cortex of the navicular bone. (18) F-NaF uptake was identified in some, but not all, osseous fragments and areas of osseous formation, suggesting a distinction between active and inactive lesions. A small number of horses were included and histopathology was not available. (18) F-NaF PET imaging of the equine distal limb provides useful additional information when compared with CT, MRI and scintigraphy and has the potential for both research and clinical applications in the horse. The Summary is available in Chinese - see Supporting information. © 2017 EVJ Ltd.

  17. Revisiting Low Energy Deuteron Production of [18F] Fluoride and Fluorine for PET

    SciTech Connect

    Barnhart, T.E.; Nickles, R.J.; Roberts, A.D.

    2003-08-26

    Fluorine-18 is currently the most widely used radioisotope in PET imaging. While much attention has been paid in recent years to production methods from 18O(p,n)18F, the current work revisits production techniques using non-enriched neon targets and the 20Ne(d,{alpha})18F reaction. While this reaction was originally pursued, and ultimately replaced by the higher yielding 18O reactions, there is an opportunity using high current low-energy deuteron accelerators and the inherent simplicity of gas targetry to provide viable alternatives to the costly 18O water target systems. 18F production systems have been developed for the gas-phase 20Ne(d,{alpha})18F reaction with deuterons from a 3MV NEC 9SDH-2 electrostatic tandem accelerator. High power target systems allowing for irradiation in excess of 100uA provided [18F]F2 yields to 86% of the theoretical maximum, and [18F]F- yields with a wash-off system of 80% of the maximum.

  18. Trojan Horse method and radioactive ion beams: study of 18F(p,α)15O reaction at astrophysical energies

    NASA Astrophysics Data System (ADS)

    Gulino, M.; Cherubini, S.; Rapisarda, G. G.; Kubono, S.; Lamia, L.; La Cognata, M.; Yamaguchi, H.; Hayakawa, S.; Wakabayashi, Y.; Iwasa, N.; Kato, S.; Komatsubara, H.; Teranishi, T.; Coc, A.; De Séréville, N.; Hammache, F.; Spitaleri, C.

    2013-03-01

    The Trojan Horse Method was applied for the first time to a Radioactive Ion Beam induced reaction to study the reaction 18F(p,α)15O via the three body reaction 18F(d,α 15O)n at the low energies relevant for astrophysics. The abundance of 18F in Nova explosions is an important issue for the understanding of this astrophysical phenomenon. For this reason it is necessary to study the nuclear reactions that produce or destroy 18F in Novae. 18F(p,α)15O is one of the main 18F destruction channels. Preliminary results are presented in this paper.

  19. No-carrier-added (NCA) aryl ([sup 18]F) fluorides via the nucleophilic aromatic substitution of electron rich aromatic rings

    DOEpatents

    Yushin Ding; Fowler, J.S.; Wolf, A.P.

    1993-10-19

    A method for synthesizing no-carrier-added (NCA) aryl [.sup.18 F] fluoride substituted aromatic aldehyde compositions bearing an electron donating group is described. The method of the present invention includes the step of reacting aromatic nitro aldehydes having a suitably protected hydroxyl substitutent on an electron rich ring. The reaction is The U.S. Government has rights in this invention pursuant to Contract Number DE-AC02-76CH00016, between the U.S. Department of Energy and Associated Universities Inc.

  20. Improved 18F Labeling of Peptides with a Fluoride-Aluminum-Chelate Complex

    PubMed Central

    McBride, William J.; D’Souza, Christopher A.; Sharkey, Robert M.; Karacay, Habibe; Rossi, Edmund A.; Chang, Chien-Hsing; Goldenberg, David M.

    2010-01-01

    We reported previously the feasibility to radiolabel peptides with fluorine-18 (18F) using a rapid, one-pot, method that first mixes 18F− with Al3+, and then binds the (Al18F)2+ complex to a NOTA ligand on the peptide. In this report, we examined several new NOTA ligands and determined how temperature, reaction time, and reagent concentration affected the radiolabeling yield. Four structural variations of the NOTA ligand had isolated radiolabeling yields ranging from 5.8% to 87% under similar reaction conditions. All of the Al18F NOTA complexes were stable in vitro in human serum and those that were tested in vivo also were stable. The radiolabeling reactions were performed at 100°C and the peptides could be labeled in as little as five minutes. The IMP467 peptide could be labeled up to 115 GBq/μmol (3100 Ci/mmol), with a total reaction and purification time of 30 min without chromatographic purification. PMID:20540570

  1. Optical reaction cell and light source for [18F] fluoride radiotracer synthesis

    DOEpatents

    Ferrieri, R.A.; Schlyer, D.; Becker, R.J.

    1998-09-15

    An apparatus is disclosed for performing organic synthetic reactions, particularly no-carrier-added nucleophilic radiofluorination reactions for PET radiotracer production. The apparatus includes an optical reaction cell and a source of broadband infrared radiant energy, which permits direct coupling of the emitted radiant energy with the reaction medium to heat the reaction medium. Preferably, the apparatus includes means for focusing the emitted radiant energy into the reaction cell, and the reaction cell itself is preferably configured to reflect transmitted radiant energy back into the reaction medium to further improve the efficiency of the apparatus. The apparatus is well suited to the production of high-yield syntheses of 2-[{sup 18}F]fluoro-2-deoxy-Dglucose. Also provided is a method for performing organic synthetic reactions, including the manufacture of [{sup 18}F]-labeled compounds useful as PET radiotracers, and particularly for the preparation of 2-[{sup 18}F]fluoro-2-deoxy-D-glucose in higher yields than previously possible. 4 figs.

  2. Optical reaction cell and light source for ›18F! fluoride radiotracer synthesis

    DOEpatents

    Ferrieri, Richard A.; Schlyer, David; Becker, Richard J.

    1998-09-15

    Apparatus for performing organic synthetic reactions, particularly no-carrier-added nucleophilic radiofluorination reactions for PET radiotracer production. The apparatus includes an optical reaction cell and a source of broadband infrared radiant energy, which permits direct coupling of the emitted radiant energy with the reaction medium to heat the reaction medium. Preferably, the apparatus includes means for focusing the emitted radiant energy into the reaction cell, and the reaction cell itself is preferably configured to reflect transmitted radiant energy back into the reaction medium to further improve the efficiency of the apparatus. The apparatus is well suited to the production of high-yield syntheses of 2-›.sup.18 F!fluoro-2-deoxy-D-glucose. Also provided is a method for performing organic synthetic reactions, including the manufacture of ›.sup.18 F!-labeled compounds useful as PET radiotracers, and particularly for the preparation of 2-›.sup.18 F!fluoro-2-deoxy-D-glucose in higher yields than previously possible.

  3. Association Between Osteogenesis and Inflammation During the Progression of Calcified Plaque Evaluated by (18)F-Fluoride and (18)F-FDG.

    PubMed

    Li, Xiang; Heber, Daniel; Cal-Gonzalez, Jacobo; Karanikas, Georgios; Mayerhoefer, Marius E; Rasul, Sazan; Beitzke, Dietrich; Zhang, Xiaoli; Agis, Hermine; Mitterhauser, Markus; Wadsak, Wolfgang; Beyer, Thomas; Loewe, Christian; Hacker, Marcus

    2017-06-01

    (18)F-FDG is the most widely validated PET tracer for the evaluation of atherosclerotic inflammation. Recently, (18)F-NaF has also been considered a potential novel biomarker of osteogenesis in atherosclerosis. We aimed to analyze the association between inflammation and osteogenesis at different stages of atherosclerosis, as well as the interrelationship between these 2 processes during disease progression. Methods: Thirty-four myeloma patients underwent (18)F-NaF and (18)F-FDG PET/CT examinations. Lesions were divided into 3 groups (noncalcified, mildly calcified, and severely calcified lesions) on the basis of calcium density as measured in Hounsfield units by CT. Tissue-to-background ratios were determined from PET for both tracers. The association between inflammation and osteogenesis during atherosclerosis progression was evaluated in 19 patients who had at least 2 examinations with both tracers. Results: There were significant correlations between the maximum tissue-to-background ratios of the 2 tracers (Spearman r = 0.5 [P < 0.01]; Pearson r = 0.4 [P < 0.01]) in the 221 lesions at baseline. The highest uptake of both tracers was observed in noncalcified lesions, but without any correlation between the tracers (Pearson r = 0.06; P = 0.76). Compared with noncalcified plaques, mildly calcified plaques showed concordant significantly lower accumulation, with good correlation between the tracers (Pearson r = 0.7; P < 0.01). In addition, enhanced osteogenesis-derived (18)F-NaF uptake and regressive inflammation-derived (18)F-FDG uptake were observed in severely calcified lesions (Pearson r = 0.4; P < 0.01). During follow-up, increased calcium density and increased mean (18)F-NaF uptake were observed, whereas mean (18)F-FDG uptake decreased. Most noncalcified (86%) and mildly calcified (81%) lesions and 47% of severely calcified lesions had concordant development of both vascular inflammation and osteogenesis. Conclusion: The combination of (18)F-NaF PET imaging

  4. Repeatability of quantitative parameters of 18F-fluoride PET/CT and biochemical tumour and specific bone remodelling markers in prostate cancer bone metastases.

    PubMed

    Wassberg, Cecilia; Lubberink, Mark; Sörensen, Jens; Johansson, Silvia

    2017-12-01

    18F-fluoride PET/CT exhibits high sensitivity to delineate and measure the extent of bone metastatic disease in patients with prostate cancer. 18F-fluoride PET/CT could potentially replace traditional bone scintigraphy in clinical routine and trials. However, more studies are needed to assess repeatability and biological uptake variation. The aim of this study was to perform test-retest analysis of quantitative PET-derived parameters and blood/serum bone turnover markers at the same time point. Ten patients with prostate cancer and verified bone metastases were prospectively included. All underwent two serial 18F-fluoride PET/CT at 1 h post-injection. Up to five dominant index lesions and whole-body 18F-fluoride skeletal tumour burden were recorded per patient. Lesion-based PET parameters were SUVmax, SUVmean and functional tumour volume applying a VOI with 50% threshold (FTV50%). The total skeletal tumour burden, total lesion 18F-fluoride (TLF), was calculated using a threshold of SUV of ≥15. Blood/serum biochemical bone turnover markers obtained at the time of each PET were PSA, ALP, S-osteocalcin, S-beta-CTx, 1CTP and BAP. A total of 47 index lesions and a range of 2-122 bone metastases per patient were evaluated. Median time between 18F-fluoride PET/CT was 7 days (range 6-8 days). Repeatability coefficients were for SUVmax 26%, SUVmean 24%, FTV50% for index lesions 23% and total skeletal tumour burden (TLF) 35%. Biochemical bone marker repeatability coefficients were for PSA 19%, ALP 23%, S-osteocalcin 18%, S-beta-CTx 22%, 1CTP 18% and BAP 23%. Quantitative 18F-fluoride uptake and simultaneous biochemical bone markers measurements are reproducible for prostate cancer metastases and show similar magnitude in test-retest variation.

  5. Baseline increased 18F-fluoride uptake lesions at vertebral corners on positron emission tomography predict new syndesmophyte development in ankylosing spondylitis: a 2-year longitudinal study.

    PubMed

    Park, Eun-Kyoung; Pak, Kyoungjune; Park, Ji-Heh; Kim, Keunyoung; Kim, Seong-Jang; Kim, In-Joo; Kim, Geun-Tae; Lee, Seung-Geun

    2017-02-02

    The goal of this study was to demonstrate whether increased 18F-fluoride uptake lesions on positron emission tomography (PET) scan can predict new syndesmophyte development in patients with ankylosing spondylitis (AS). In 12 AS patients, 18F-fluoride PET and magnetic resonance imaging (MRI) was performed at baseline, and radiography was performed at baseline and the 2-year follow-up. The following data were recorded: the presence of increased 18F-fluoride uptake lesions on PET defined as an uptake greater than the uptake in the adjacent normal vertebral body; acute (type A) and advanced (type B) corner inflammatory lesions (CILs) and fat lesions on MRI; and syndesmophytes on radiography. Of 231 anterior vertebral corners without syndesmophyte at baseline, 13 type A CILs (5.5%), 2 type B CILs (0.9%), and 20 fat lesions (8.7%) on MRI and six increased fluoride uptake lesions (2.6%) on PET were observed. At the 2-year follow-up, 16 new syndesmophytes (6.9%) in eight AS patients (66.7%) occurred. New syndesmophytes developed significantly more frequently in anterior vertebral corners with increased 18F-fluoride uptake lesions (50%) or fat lesions (25%) at baseline than in those without such lesions (5.8 and 5.2%; p = 0.005 and p = 0.007, respectively). After adjusting confounding factors, baseline increased 18F-fluoride uptake lesions was independently associated with new syndesmophytes development (OR 13.8, 95% CI 1.5-124.3, p = 0.019). Fat lesions were also associated with new syndesmophytes formation. Our data suggest that 18F-fluoride PET may be applied to identify AS patients with high risk of future syndesmophyte formation.

  6. Evaluation of lesion in a spontaneous osteonecrosis of the knee using 18F-fluoride positron emission tomography.

    PubMed

    Aratake, Masato; Yoshifumi, Tayama; Takahashi, Akira; Takeuchi, Ryohei; Inoue, Tomio; Saito, Tomoyuki

    2009-01-01

    Positron-emission tomography (PET) imaging has several advantages over conventional scintigraphy, including a high spatial resolution and the ability to quantify disease progression. Recently, (18)F-fluoride PET has been applied to the evaluation of malignant tumors and musculoskeletal disorders. In our current study, spontaneous osteonecrosis of the knee (SONK) was visualized using this technique. We determined whether PET images can reveal SONK lesions, whether there were significant differences in the maximum standardized uptake value (SUVmax) among each of the SONK stages, and finally if there was any correlation between the maximum SUVmax value and size of the SONK lesion measured both by radiography and MRI. Fourteen knees from 13 patients diagnosed with SONK were imaged using a PET scanner. In all cases, PET showed an accumulation of 18F-fluoride in the medial condyle. The SUVmax ranged from 8.6 to 23.7 with an average of 15.1 +/- 3.7 and was measured at different disease stages with an average of 12.4 +/- 5.9 in Stage 2 (n = 5), 16.3 +/- 1.4 in Stage 3 (n = 4), and 16.8 +/- 4.3 (n = 5) in Stage 4 lesions. There were no significant differences in these measurements between the SONK stages. However, a significant positive correlation between the SUVmax and lesion size, including the surface area of the lesion (r2 = 0.692, P = 0.0002) and the condyle width ratio (r2 = 0.365, P = 0.022), was found. The approximate volumes of the lesions measured by MRI had an average of 4.8 +/- 3.1 cm3, and also showed a significant correlation with the SUVmax (r2 = 0.853, P < 0.0001). Hence, our present results indicate that a high SUV is indicative of a large SONK lesion.

  7. Evaluation of new bone formation in normal and osteoporotic rats with a 3-mm femur defect: functional assessment with dynamic PET-CT (dPET-CT) using 2-deoxy-2-[(18)F]fluoro-D-glucose ( (18)F-FDG) and (18)F-fluoride.

    PubMed

    Cheng, Caixia; Alt, Volker; Dimitrakopoulou-Strauss, Antonia; Pan, Leyun; Thormann, Ulrich; Schnettler, Reinhard; Weber, Klaus; Strauss, Ludwig G

    2013-06-01

    The aim of the current study was to assess the formation of new bone in a 3-mm created defect in the femur and its adjacent bone tissue in osteoporotic and normal animals. The assessment is based on bone remodeling and glucose metabolism in a rat model with a 3-mm created defct in the femur using (18)F-fluoride and 2-deoxy-2-[(18)F]fluoro-D-glucose ((18)F-FDG) as tracers for dynamic PET-CT (dPET-CT). The (18)F-fluoride PET data were compared with those of (18)F-FDG. Osteoporosis was induced by ovariectomy and a calcium restricted diet in each rat (n = 7). Alternatively, a sham operation was performed in the control group (n = 8). After 3 months, all rats were operated to create a 3-mm defect using an oscillating saw in the distal metaphyseal femur, which was internally fixed with a metal plate. Eighteen weeks after osteoporosis induction and 6 weeks following femoral surgery, dPET-CT studies scan were performed with (18)F-FDG and (18)F-fluoride. Following PET data acquisition, standardized uptake values (SUVs) were calculated from the tracer concentration values. Then, a two-tissue compartmental learning-machine model was applied to the data for the calculation of the compartment parameters (K1-k4, VB, Ki). Furthermore, a non-compartmental model based on the fractal dimension was applied for quantitative analysis of both groups and both tracers. Finally, multivariate analysis was performed for the statistical analysis of the kinetic data. The values for K1 and Ki were higher in the osteoporotic rats than in the control group. Ki and K1 of (18)F-fluoride in the adjacent bone tissue differ significantly based on the Wilcoxon rank-sum test for the osteoporotic and control group (p < 0.05). The sensitivity and the negative predictive value (NPV) based on linear discriminant analysis was high with a value of 100 % for both tracers and both evaluated regions (defect and adjacent bone tissue) when comparing control and osteoporotic rats. The overall

  8. Skeletal Tumor Burden on Baseline 18F-Fluoride PET/CT Predicts Bone Marrow Failure After 223Ra Therapy.

    PubMed

    Etchebehere, Elba C; Araujo, John C; Milton, Denái R; Erwin, William D; Wendt, Richard E; Swanston, Nancy M; Fox, Patricia; Macapinlac, Homer A; Rohren, Eric M

    2016-04-01

    Determine if skeletal tumor burden on 18F-fluoride PET/CT (fluoride PET/CT) predicts the risk of bone marrow failure (BMF) after 223Ra dichloride therapy (223Ra). Forty-one metastatic prostate cancer patients (43-89 years old; mean, 71 ± 9 years.) underwent fluoride PET/CT prior to 223Ra. Bone marrow failure was the primary end point and was defined as (1) development of hematologic toxicity (World Health Organization grade 3 or 4) associated with no recovery after 6 weeks or (2) death due to BMF after the last 223Ra dose. Bone marrow failure was correlated to fluoride PET/CT skeletal tumor burden (TLF10 [total lesion on fluoride PET/CT with SUVmax of 10 or greater]), use of chemotherapy, serum hemoglobin concentration, serum ALP, and serum prostate-specific antigen. The number of 223Ra cycles ranged from 2 to 6 (mean, 5). Of the 41 patients, 16 developed BMF (G3 = 12; G4 = 4). A significantly increased risk of developing BMF was observed in patients with TLF10 of 12,000 or greater (hazard ratio [HR], 11.09; P < 0.0001), hemoglobin of less than 10 g/dL (HR, 7.35; P = 0.0002), and AP > 146 UI/L (HR, 4.52; P = 0.0100). Neither concomitant (HR, 0.91; P = 0.88) nor subsequent use of chemotherapy (HR, 0.14; P = 0.84) increased the risk of BMF, nor was prostate-specific antigen greater than 10 μg/L (HR, 0.90; P = 0.86). Moreover, in a multivariable analysis, TLF10 was the only independent predictor of BMF (HR, 6.66; P = 0.0237). 223Ra was beneficial and reduced the risk of death even in patients with a high skeletal tumor burden. Fluoride PET/CT is able to determine which patients will benefit from 223Ra and which will develop BMF.

  9. The Kinetics and Reproducibility of 18F-Sodium Fluoride for Oncology Using Current PET Camera Technology

    PubMed Central

    Kurdziel, Karen A.; Shih, Joanna H.; Apolo, Andrea B.; Lindenberg, Liza; Mena, Esther; McKinney, Yolanda; Adler, Stephen S.; Turkbey, Baris; Dahut, William; Gulley, James L.; Madan, Ravi A.; Landgren, Ola; Choyke, Peter L.

    2012-01-01

    We evaluated the kinetics of 18F-sodium fluoride (NaF) and reassessed the recommended dose, optimal uptake period, and reproducibility using a current-generation PET/CT scanner. Methods In this prospective study, 73 patients (31 patients with multiple myeloma or myeloma precursor disease and 42 with prostate cancer) were injected with a mean administered dose of 141 MBq of 18F-NaF. Sixty patients underwent 3 sequential sessions of 3-dimensional PET/CT of the torso beginning ~15 min after 18F-NaF injection, followed by a whole-body 3-dimensional PET/CT at 2 h. The remaining 13 prostate cancer patients were imaged only at 2 and 3 h after injection. Twenty-one prostate cancer patients underwent repeat baseline studies (mean interval, 5.9 d) to evaluate reproducibility. Results The measured effective dose was 0.017 mSv/MBq, with the urinary bladder, osteogenic cells, and red marrow receiving the highest doses at 0.080, 0.077, and 0.028 mGy/MBq, respectively. Visual analysis showed that uptake in both normal and abnormal bone increased with time; however, the rate of increase decreased with time. A semiautomated workflow provided objective uptake parameters, including the mean standardized uptake value of all pixels within bone with SUVs greater than 10 and the average of the mean SUV of all malignant lesions identified by the algorithm. The values of these parameters for the images beginning at ~15 min and ~35 min were significantly different (0.3% change/minute). Differences between the later imaging time points were not significant (P < 0.01). Repeat baseline studies showed high intraclass correlations (>0.9) and relatively low critical percent change (the value above which a change can be considered real) for these parameters. The tumor-to-normal bone ratio, based on the SUVmax of identified malignant lesions, decreased with time; however, this difference was small, estimated at ~0.16%/min in the first hour. Conclusion 18F-NaF PET/CT images obtained with modest

  10. The Role of 18F-Sodium Fluoride PET/CT Bone Scans in the Diagnosis of Metastatic Bone Disease from Breast and Prostate Cancer.

    PubMed

    Kulshrestha, Randeep Kumar; Vinjamuri, Sobhan; England, Andrew; Nightingale, Julie; Hogg, Peter

    2016-12-01

    We describe the role of (18)F-sodium fluoride ((18)F-NaF) PET/CT bone scanning in the staging of breast and prostate cancer. (18)F-NaF PET was initially utilized as a bone scanning agent in the 1960s and early 1970s, however, its use was restricted by the then-available γ-cameras. The advent of hybrid PET/CT cameras in the late 1990s has shown a resurgence of interest in its use and role. After a brief introduction, this paper describes the radiopharmaceutical properties, dosimetry, pharmacokinetics, and mechanism of uptake of (18)F-NaF. The performance of (18)F-NaF PET/CT is then compared with that of conventional bone scintigraphy using current evidence from the literature. Strengths and weaknesses of (18)F-NaF PET/CT imaging are highlighted. Clinical examples of improved accuracy of diagnosis and impact on patient management are illustrated. Limitations of (18)F-NaF PET/CT imaging are outlined.

  11. Double-grid [ 18O]water target for high yield of [ 18F]fluoride production on KIRMAS-13

    NASA Astrophysics Data System (ADS)

    Hong, Bong Hwan; An, Dong Hyun; Chai, Jong Seo; Chang, Hong Suk; Hur, Min Goo; Jung, In Su; Kim, Sangwook; Kim, Yu Seok; Yang, Tae Keun

    2005-12-01

    [18O]water targets were constructed to install on the 13 MeV KIRAMS-13 medical cyclotron for high yield of [18F]fluoride production from enriched [18O]water. Central cavity in titanium body contain [18O]water. Shape of cavity has two different geometries along incident direction of beam. Front volume has a cylinder shape and rear cavity has a fan shape with larger volume to gather ascent vapor bubbles and increase heat transfer area. Total volume of cavity is 1.6 ml. Both open sides of cavity are block with 50 μm titanium foils. Two aluminum grids are placed out side of each foil. Front water-cooled type gird is directly place in the vacuum beam line. Grids were adapted to cool foils and prevent their thermal expansion under high pressure. The target yield is 50 mCi/μA h under 12.5 MeV incident proton beam.

  12. First results of Trojan horse method using radioactive ion beams: 18F(p,α) at astrophysical energies

    NASA Astrophysics Data System (ADS)

    Cherubini, S.; Gulino, M.; Spitaleri, C.; La Cognata, M.; Lamia, L.; Puglia, S.; Rapisarda, G.; Romano, S.; Kubono, S.; Yamaguchi, H.; Binh, D.; Hayakawa, S.; Kurihara, Y.; Wakabayashi, Y.; Bishop, S.; Coc, A.; De Séréville, N.; Hammache, F.

    2014-05-01

    The abundance of 18F in Nova explosions is considered to be an important piece of information for the understanding of this astrophysical phenomenon. It is then necessary to study the nuclear processess that both produce and destroy this isotope in Novae. Among these latter reactions, the 18F(p,α)15O is one of the most important 18F destruction channels. Here we report on an experiment performed using the CRIB apparatus of the Center for Nuclear Study of the University of Tokyo. This was the first experiment that used the Trojan Horse method applied to a Radioactive Ion Beam induced reaction.

  13. First results of Trojan horse method using radioactive ion beams: {sup 18}F(p,α) at astrophysical energies

    SciTech Connect

    Cherubini, S.; Spitaleri, C.; Puglia, S.; Rapisarda, G.; Romano, S.; Gulino, M.; La Cognata, M.; Lamia, L.; Kubono, S.; Wakabayashi, Y.; Yamaguchi, H.; Hayakawa, S.; Kurihara, Y.; Binh, D.; Bishop, S.; Coc, A.; De Séréville, N.; Hammache, F.

    2014-05-02

    The abundance of {sup 18}F in Nova explosions is considered to be an important piece of information for the understanding of this astrophysical phenomenon. It is then necessary to study the nuclear processess that both produce and destroy this isotope in Novae. Among these latter reactions, the {sup 18}F(p,α){sup 15}O is one of the most important {sup 18}F destruction channels. Here we report on an experiment performed using the CRIB apparatus of the Center for Nuclear Study of the University of Tokyo. This was the first experiment that used the Trojan Horse method applied to a Radioactive Ion Beam induced reaction.

  14. (18)F-sodium fluoride PET/CT for the in vivo visualization of Mönckeberg's sclerosis in a diabetic patient.

    PubMed

    Quirce, R; Martínez-Rodríguez, I; Banzo, I; de Arcocha-Torres, M; Jiménez-Bonilla, J F; Martínez-Amador, N; Ibáñez-Bravo, S; Ramos, L; Amado, J A; Carril, J M

    2015-01-01

    Diabetes is a major frequent cause of atherosclerosis vascular disease. Arterial calcification in diabetic patients is responsible for peripheral vascular involvement. Molecular imaging using (18)F-sodium fluoride ((18)F-NaF) positron emission tomography (PET)/computed tomography (CT) has been recently proposed as a marker to study the in vivo mineralization process in the atheroma plaque. A 69-year-old man with a history of type 2 diabetes and no clinical evidence of peripheral arterial disease underwent an (18)F-NaF PET/CT scan. A linear, well-defined (18)F-NaF uptake was detected along the femoral arteries. In addition, the CT component of the PET/CT identified an unsuspected "tram-track" calcification in his femoral arteries, suggestive of medial calcification (Mönckeberg's sclerosis). In other vascular territories, focal (18)F-NaF uptake was also detected in carotid and aorta atheroma plaques. Molecular imaging with (18)F-NaF PET/CT might provide new functional information about the in vivo vascular calcification process in diabetic patients.

  15. 18F-fluoride PET used for treatment monitoring of systemic cancer therapy: results from the National Oncologic PET Registry.

    PubMed

    Hillner, Bruce E; Siegel, Barry A; Hanna, Lucy; Duan, Fenghai; Quinn, Bruce; Shields, Anthony F

    2015-02-01

    In a national prospective registry, we previously studied the impact of (18)F-sodium fluoride PET (NaF PET) on the intended management of cancer patients with osseous metastases. The clinical impact of NaF PET for monitoring the response to systemic therapies in such patients is unknown. The objective of this study was to assess the impact of NaF PET results obtained for treatment monitoring of systemic cancer therapy. Before and after NaF PET, we collected prospective data from referring and interpreting physicians for cancer patients 65 y or older receiving systemic therapy (use of 1 or more categories including hormonal, chemotherapy, bisphosphonates, or immunotherapy). The analysis set consisted of 2,217 patients who underwent 2,839 scans (68% prostate, 17% breast, 6% lung, and 8% other cancers) ordered for treatment monitoring. Two or more categories of systemic therapy were planned in 56% of prostate and 43% of breast cancer patients. The overall rates of prior radionuclide bone imaging were 78%, 76%, and 66% for prostate, breast, and other cancers, respectively. Fifty-seven percent of patients underwent prior NaF PET. Overall change in management associated with NaF PET was 40%. In patients with prior NaF PET scans for comparison, continuing current therapy was planned in 79% when scans showed no change or a decrease or absence of osseous metastasis. Treating physicians planned to switch therapy in 59% of patients after scans showed evidence of new or progressive metastasis. When an additional parameter, estimated prognosis, was worse, switching therapy was even more common (76%). The impact of NaF PET used for treatment monitoring was high in patients with evidence of progressive osseous metastasis. Most such patients had plans to switch to a new cancer-directed therapy. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  16. Evolving Role of Molecular Imaging with (18)F-Sodium Fluoride PET as a Biomarker for Calcium Metabolism.

    PubMed

    Raynor, William; Houshmand, Sina; Gholami, Saeid; Emamzadehfard, Sahra; Rajapakse, Chamith S; Blomberg, Björn Alexander; Werner, Thomas J; Høilund-Carlsen, Poul F; Baker, Joshua F; Alavi, Abass

    2016-08-01

    (18)F-sodium fluoride (NaF) as an imaging tracer portrays calcium metabolic activity either in the osseous structures or in soft tissue. Currently, clinical use of NaF-PET is confined to detecting metastasis to the bone, but this approach reveals indirect evidence for disease activity and will have limited use in the future in favor of more direct approaches that visualize cancer cells in the read marrow where they reside. This has proven to be the case with FDG-PET imaging in most cancers. However, a variety of studies support the application of NaF-PET to assess benign osseous diseases. In particular, bone turnover can be measured from NaF uptake to diagnose osteoporosis. Several studies have evaluated the efficacy of bisphosphonates and their lasting effects as treatment for osteoporosis using bone turnover measured by NaF-PET. Additionally, NaF uptake in vessels tracks calcification in the plaques at the molecular level, which is relevant to coronary artery disease. Also, NaF-PET imaging of diseased joints is able to project disease progression in osteoarthritis, rheumatoid arthritis, and ankylosing spondylitis. Further studies suggest potential use of NaF-PET in domains such as back pain, osteosarcoma, stress-related fracture, and bisphosphonate-induced osteonecrosis of the jaw. The critical role of NaF-PET in disease detection and characterization of many musculoskeletal disorders has been clearly demonstrated in the literature, and these methods will become more widespread in the future. The data from PET imaging are quantitative in nature, and as such, it adds a major dimension to assessing disease activity.

  17. Impact of Personal Characteristics and Technical Factors on Quantification of Sodium 18F-Fluoride Uptake in Human Arteries: Prospective Evaluation of Healthy Subjects.

    PubMed

    Blomberg, Björn Alexander; Thomassen, Anders; de Jong, Pim A; Simonsen, Jane A; Lam, Marnix G E H; Nielsen, Anne L; Mickley, Hans; Mali, Willem P T M; Alavi, Abass; Høilund-Carlsen, Poul F

    2015-10-01

    Sodium 18F-fluoride (18F-NaF) PET/CT imaging is a promising imaging technique for the assessment of atherosclerosis but is hampered by a lack of validated quantification protocols. Both personal characteristics and technical factors can affect quantification of arterial 18F-NaF uptake. This study investigated whether blood activity, renal function, injected dose, circulating time, and PET/CT system affect quantification of arterial 18F-NaF uptake. Eighty-nine healthy subjects were prospectively examined by 18F-NaF PET/CT imaging. Arterial 18F-NaF uptake was quantified at the level of the ascending aorta, aortic arch, descending thoracic aorta, and coronary arteries by calculating the maximum 18F-NaF activity (NaFmax), the maximum/mean target-to-background ratio (TBRmax/mean), and the maximum blood-subtracted 18F-NaF activity (bsNaFmax). Multivariable linear regression assessed the effect of personal characteristics and technical factors on quantification of arterial 18F-NaF uptake. NaFmax and TBRmax/mean were dependent on blood activity (β=0.34 to 0.44, P<0.001, and β=-0.68 to -0.58, P<0.001, respectively) and PET/CT system (β=-0.80 to -0.53, P<0.001, and β=-0.80 to -0.23, P<0.031, respectively). bsNaFmax depended on PET/CT system (β=-0.91 to -0.57, P<0.001) but not blood activity. This finding was observed at the level of the ascending aorta, aortic arch, descending thoracic aorta, and the coronary arteries. In addition to blood activity and PET/CT system, injected dose affected quantification of arterial 18F-NaF uptake, whereas renal function and circulating time did not. The prospective evaluation of 89 healthy subjects demonstrated that quantification of arterial 18F-NaF uptake is affected by blood activity, injected dose, and PET/CT system. Therefore, blood activity, injected dose, and PET/CT system should be considered to generate accurate estimates of arterial 18F-NaF uptake. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  18. 18F-fluoride PET/CT scan for quantification of bone metabolism in the inner ear in patients with otosclerosis--a pilot study.

    PubMed

    Waterval, Jérôme J; Vallinga, Maud; Brans, Boudewijn; Winkens, Bjorn; Stokroos, Robert J

    2013-09-01

    In otosclerosis, CT of the temporal bone is used to confirm the diagnosis. Whereas CT is a static diagnostic tool displaying the demineralization caused by otosclerosis, imaging of bone metabolism by (18)F-fluoride PET may provide quantitative information. This could be useful for prognosis and stratification of patients. The aim of this study was to assess (18)F-fluoride activity in patients with otosclerosis and to evaluate its use as a complementary diagnostic tool. All patients with otosclerosis underwent a PET/CT scan. Audiometric data were collected. The severity of otosclerosis was assessed using a recognized radiological classification. The control group consisted of patients who had undergone (18)F-fluoride PET/CT scan for orthopedic purpose. Regions of interest were drawn on PET scans which corresponded to standardized anatomical sites as defined on CT, to measure bone metabolism using standardized uptake values (SUV(max) and SUV(mean)). Group 1 consisted of 11 otosclerosis patients (16 eligible temporal bones) and group 2 consisted of 5 control patients (10 temporal bones). On PET scan, visual assessment of temporal bones with otosclerosis showed increased metabolic activity in the otic capsule in 11/16 cases. The SUV(max) in the entire otic capsule was significantly higher in otosclerosis patients compared to control subjects. Significant differences in SUV(mean) were found between otosclerosis and control subjects in the fenestral and saccule area. Moreover, metabolic activity in these regions significantly correlated with hearing loss and CT classification. (18)F-Fluoride PET scanning using SUV measurements has the potential to be a diagnostic tool in otosclerosis.

  19. Assessment of Whether Patients' Knowledge, Satisfaction, and Experience Regarding Their 18F-Fluoride PET/CT Examination Affects Image Quality.

    PubMed

    Andersson, Camilla; Johansson, Birgitta; Wassberg, Cecilia; Johansson, Silvia; Sundin, Anders; Ahlström, Håkan

    2016-03-01

    The aim of this study was to investigate patients' previous knowledge, satisfaction, and experience regarding an (18)F-fluoride PET/CT examination and to explore whether any discomfort or pain during the examination was associated with reduced image quality. A further aim was to explore whether patients' health-related quality of life (HRQoL) was associated with their satisfaction and experience regarding the examination. Between November 2011 and April 2013, 50 consecutive patients with a histopathologic diagnosis of prostate cancer who were scheduled for (18)F-fluoride PET/CT were asked to participate in the study. A questionnaire was used to collect information on the patients' previous knowledge and experience regarding the examination. Image quality was assessed according to an arbitrary scale. The European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ-C30) and the prostate cancer-specific module (QLQ-PR25) were used to assess HRQoL. Forty-six patients (96%) completed the questionnaire. Twenty-six percent did not at all know what a (18)F-fluoride PET/CT examination was. Most (52%-70%) were satisfied to a very high degree with the care provided by the nursing staff but were less satisfied with the information given before the examination. Image quality was similar between patients who were exhausted or claustrophobic during the examination and those who were not. No correlations between HRQoL and the patients' experience regarding (18)F-fluoride PET/CT were found. Most patients were satisfied with the care provided by the nursing staff, but there is still room for improvement, especially regarding the information provided before the examination. A long examination time may be strenuous for the patient, but there was no difference in image quality between patients who felt discomfort or pain during the examination and those who did not. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  20. Niobium sputtered Havar foils for the high-power production of reactive [18F]fluoride by proton irradiation of [18O]H2O targets.

    PubMed

    Wilson, J S; Avila-Rodriguez, M A; Johnson, R R; Zyuzin, A; McQuarrie, S A

    2008-05-01

    Niobium sputtered Havar entrance foils were used for the production of reactive [(18)F]fluoride by proton irradiation of [(18)O]H(2)O targets under pressurized conditions. The synthesis yield in the routine production of 2-[(18)F]fluoro-2-deoxy-glucose (FDG) was used as an indicative parameter of the reactivity of (18)F. The yield of FDG obtained with (18)F produced in a target with Havar foil was used as a baseline. No statistically significant difference was found in the saturated yields of (18)F when using Havar or Havar-Nb sputtered entrance foils. However, the amount of long-lived radionuclidic impurities decreased more than 10-fold using the Havar-Nb entrance foil. The average decay corrected synthesis yield of FDG, evaluated over a period of more than 2 years, was found to be approximately 5% higher when using a Havar-Nb entrance foil and a marked improvement on the FDG yield consistency was noted. In addition, the frequency of target rebuilding was greatly diminished when using the Nb sputtered entrance foil.

  1. A prospective study comparing (99m)Tc-HDP planar bone scintigraphy and whole-body SPECT/CT with (18)F-fluoride PET/CT and (18)F-fluoride PET/MRI for diagnosing bone metastases.

    PubMed

    Löfgren, Johan; Mortensen, Jann; Rasmussen, Sine Hvid; Madsen, Claus; Loft, Annika; Hansen, Adam Espe; Oturai, Peter; Jensen, Karl Erik; Mørk, Mette Louise; Reichkendler, Michala; Højgaard, Liselotte; Fischer, Barbara M

    2017-08-10

    We prospectively evaluate and compare the diagnostic performance of (99m)Tc-HDP planar bone scintigraphy (pBS), (99m)Tc-HDP SPECT/CT, (18)F-NaF PET/CT and (18)F-NaF PET/MRI for the detection of bone metastases. Methods: 117 patients with histologically proven malignancy referred for clinical pBS were prospectively enrolled. pBS and whole-body SPECT/CT were performed followed by (18)F-NaF PET/CT within 9 days. (18)F-NaF PET/MRI was also performed in 46 patients. A "truth panel" including clinical follow-up served as standard of reference. Results: Bone metastases were confirmed in 16 patients and excluded in 101. When equivocal readings were excluded no statistically significant difference in sensitivity, specificity, PPV, NPV or overall accuracy were found when comparing the different imaging techniques. With a pessimistic analysis, interpreting equivocal scans as positive, (18)F-NaF-PET showed a significant higher specificity and accuracy than pBS (93.1% vs 81.2%, P = 0.012 and 91.5% vs. 79.5%, P = 0.011). With an optimistic analysis, interpreting equivocal scans as negative, (18)F-NaF-PET showed significant higher accuracy than SPECT/CT (94.9% vs. 88.0%, P = 0.039) but not compared to pBS. The number of equivocal scans were significantly higher for pBS than for SPECT/CT and PET/CT (18 vs 5 and 6 respectively, P = 0.004 resp. P = 0.01). Conclusion:(18)F-NaF PET/CT and whole body SPECT/CT resulted in a significant reduction of equivocal readings compared to pBS which implies an improved diagnostic confidence. However, this large prospective study could not verify prior published results on (18)F-NaF-PET/CT superior overall accuracy compared to neither pBS nor whole-body SPECT/CT. The subgroup analysis of 46 patients with (18)F-NaF-PET/MRI failed to demonstrate significantly improved overall diagnostic accuracy. Copyright © 2017 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  2. The role of PET/CT in evaluation of Facet and Disc abnormalities in patients with low back pain using (18)F-Fluoride.

    PubMed

    Gamie, Sherief; El-Maghraby, Tarek

    2008-01-01

    Bone scintigraphy including Single Photon Emission Computed Tomography (SPECT) is known for its role in the diagnosis of low back pain disorders. Positron Emission Tomography (PET) with (18)F (Flouride-18) as a tracer can be used to carry out bone scans with improved image quality. With the addition of CT, simultaneous PET/CT fused images provide more accurate anatomical details. The objectives of this work are to assess the use of (18)F-PET/CT in patients with back pain and suspected facetogenic pain, and to find the frequency of facet arthropathy versus disc disease abnormalities. 67 patients who presented with back pain underwent routine X-ray, CT and/or MRI, which failed to identify a clear cause, were referred to (18)F-PET/CT. Among the main group, a subset of 25 patients had previous spine surgery consisting of laminectomy or discectomy (17 patients) and lumbar fusion (8 patients). The PET/CT scan was acquired on a GE VCT 64-Slice combined scanner. Imaging started 45-60 minutes after administration of 12-15 mCi (444-555 MBq) of (18)F-Fluoride. The PET scan was acquired from the skull base through the inguinal region in 3D mode at 2 minutes/bed. A lowresolution, non-contrast CT scan was also acquired for anatomic localization and attenuation correction. The (18)F-PET/CT showed abnormal uptake in the spine in 56 patients, with an overall detection ability of 84%. Facet joints as a cause of back pain was much more frequent (25 with abnormal scans). One-third (36%) of the patients showed multiple positive uptake in both facet joints and disc areas (20/56). The patients were further divided into two groups. Group A consisted of 42 patients (63%) with back pain and no previous operative procedures, and the (18)F-PET/CT showed a high sensitivity (88%) in identifying the source of pain in 37/42 patients. Group B included 25 patients (37%) with prior lumbar fusion or laminectomy, in which the PET/CT showed positive uptake in 76% (19/25 patients). (18)F-PET/CT showed

  3. Prognostic Factors in Patients Treated with 223Ra: The Role of Skeletal Tumor Burden on Baseline 18F-Fluoride PET/CT in Predicting Overall Survival.

    PubMed

    Etchebehere, Elba C; Araujo, John C; Fox, Patricia S; Swanston, Nancy M; Macapinlac, Homer A; Rohren, Eric M

    2015-08-01

    The purpose of this study was to evaluate outcome after (223)Ra dichloride therapy ((223)Ra) and to determine whether skeletal tumor burden on whole-body (18)F-fluoride PET/CT can be used as a predictive biomarker of survival in patients treated with (223)Ra. Forty-two patients with hormone-refractory prostate cancer underwent (223)Ra and a baseline fluoride PET/CT scan. Fluoride PET/CT parameters were generated, including maximum standardized uptake value (SUVmax) of the hottest lesion (hSUVmax), average SUV of disease (Mean10), and skeletal tumor burden indices of total fluoride skeletal metastatic lesion uptake (TLF10) and total volume of fluoride avid bone metastases (FTV10). Overall survival (OS) was the primary endpoint. Secondary endpoints were progression-free survival and skeletal-related event (SRE). Skeletal tumor burden indices (TLF10 and FTV10) derived from fluoride PET/CT at baseline were highly correlated and significant independent predictors of OS (P = 0.0212; hazard ratio = 5.990; 95% confidence interval = 1.306-27.475). A TLF10 cutoff value of 8,000 discriminated survivors from nonsurvivors after (223)Ra (with TLF10 values < 8,000, the median OS was not estimated, whereas with TLF10 > 8,000, the median OS was 6.67 mo). Visual analysis, Mean10, and hSUVmax were not predictors of OS or progression-free survival. Mean10 was found to be a significant univariate predictor of the odds of having an SRE (P = 0.0445; odds ratio = 1.30; 95% confidence interval = 1.006-1.681), with a Mean10 greater than 19 increasing the risk of SRE. Skeletal tumor burden on baseline fluoride PET/CT is a predictive biomarker of OS and the risk of an SRE in patients treated with (223)Ra. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  4. Impact of 18F-fluoride PET in patients with known prostate cancer: initial results from the National Oncologic PET Registry.

    PubMed

    Hillner, Bruce E; Siegel, Barry A; Hanna, Lucy; Duan, Fenghai; Shields, Anthony F; Coleman, R Edward

    2014-04-01

    Under Medicare's Coverage with Evidence Development policy, PET using (18)F-sodium fluoride (NaF PET) to identify osseous metastasis became a covered service if prospective registry data were collected. The National Oncologic PET Registry (NOPR) developed a NaF PET registry built on the foundation of its prior registry for PET with (18)F-FDG. Men with prostate cancer represented 72% of the cases. Prospective data before and after NaF PET were collected from referring and interpreting physicians. The analysis set consisted of consenting men age 65 y or older with prostate cancer undergoing NaF PET for initial staging (IS, n = 1,024), suspected first osseous metastasis (FOM, n = 1,997), or suspected progression of osseous metastasis (POM, n = 510). Referring physicians indicated that if NaF PET were not available, other advanced imaging (body CT, MR imaging, or (18)F-FDG PET) would be their plan in about half of the cases. After NaF PET, the postimaging plan was revised to treatment in 77%, 52%, and 71% for IS, FOM, and POM, respectively. When intended management was classified as either treatment or nontreatment, the overall change in intended management ranged from 44% to 52% and from 12% to 16% if no effect was assumed for those cases with pre-PET plans for other imaging (imaging-adjusted impact). Interpreting physicians recorded definite findings of bone metastasis in 14%, 29%, and 76% for IS, FOM, and POM, respectively. The intended care patterns varied widely across indication and scan abnormality category combinations. NaF PET has high overall impact, principally related to its effect on replacing intended use of other advanced imaging. Its imaging-adjusted impact was similar to that observed with (18)F-FDG PET for restaging or suspected recurrence in other cancer types.

  5. Castration-Resistant Prostate Cancer Bone Metastasis Response Measured by 18F-Fluoride PET After Treatment with Dasatinib and Correlation with Progression-Free Survival: Results from American College of Radiology Imaging Network 6687

    PubMed Central

    Yu, Evan Y.; Duan, Fenghai; Muzi, Mark; Deng, Xuan; Chin, Bennett B.; Alumkal, Joshi J.; Taplin, Mary-Ellen; Taub, Jina M.; Herman, Ben; Higano, Celestia S.; Doot, Robert K.; Hartfeil, Donna; Febbo, Philip G.; Mankoff, David A.

    2015-01-01

    18F-fluoride PET quantitatively images bone metabolism and may serve as a pharmacodynamic assessment for systemic therapy such as dasatinib, a potent SRC kinase inhibitor, with activity in bone. Methods This was an imaging companion trial (American College of Radiology Imaging Network [ACRIN] 6687) to a multicenter metastatic castration-resistant prostate cancer (CRPC) tissue biomarker–guided therapeutic trial (NCT00918385). Men with bone metastatic CRPC underwent 18F-fluoride PET before and 12 weeks after initiation of dasatinib (100 mg daily). Dynamic imaging was performed over a 15-cm field of view for trial assessments. The primary endpoint was to determine whether changes in 18F-fluoride incorporation in tumor and normal bone occurred in response to dasatinib. Other endpoints included differential effect of dasatinib between 18F-fluoride incorporation in tumor and normal bone, 18F-fluoride transport in bone metastases, correlation with progression-free survival (PFS), prostate-specific antigen, and markers of bone turnover. Results Eighteen participants enrolled, and 17 underwent interpretable baseline 18F-fluoride PET imaging before initiation of dasatinib. Twelve of 17 patients underwent on-treatment PET imaging. Statistically significant changes in response to dasatinib were identified by the SUVmaxavg (average of maximum standardized uptake value [SUVmax] for up to 5 tumors within the dynamic field of view) in bone metastases (P = 0.0002), with a significant differential 18F-fluoride PET response between tumor and normal bone (P < 0.0001). Changes in 18F-fluoride incorporation in bone metastases had borderline correlation with PFS by SUVmaxavg (hazard ratio, 0.91; 95% confidence interval, 0.82–1.00; P = 0.056). Changes by SUVmaxavg correlated with bone alkaline phosphatase (P = 0.0014) but not prostate-specific antigen (P = 0.47). Conclusion: This trial provides evidence of the ability 18F-fluoride PET to delineate treatment response of dasatinib in

  6. Castration-resistant prostate cancer bone metastasis response measured by 18F-fluoride PET after treatment with dasatinib and correlation with progression-free survival: results from American College of Radiology Imaging Network 6687.

    PubMed

    Yu, Evan Y; Duan, Fenghai; Muzi, Mark; Deng, Xuan; Chin, Bennett B; Alumkal, Joshi J; Taplin, Mary-Ellen; Taub, Jina M; Herman, Ben; Higano, Celestia S; Doot, Robert K; Hartfeil, Donna; Febbo, Philip G; Mankoff, David A

    2015-03-01

    (18)F-fluoride PET quantitatively images bone metabolism and may serve as a pharmacodynamic assessment for systemic therapy such as dasatinib, a potent SRC kinase inhibitor, with activity in bone. This was an imaging companion trial (American College of Radiology Imaging Network [ACRIN] 6687) to a multicenter metastatic castration-resistant prostate cancer (CRPC) tissue biomarker-guided therapeutic trial (NCT00918385). Men with bone metastatic CRPC underwent (18)F-fluoride PET before and 12 weeks after initiation of dasatinib (100 mg daily). Dynamic imaging was performed over a 15-cm field of view for trial assessments. The primary endpoint was to determine whether changes in (18)F-fluoride incorporation in tumor and normal bone occurred in response to dasatinib. Other endpoints included differential effect of dasatinib between (18)F-fluoride incorporation in tumor and normal bone, (18)F-fluoride transport in bone metastases, correlation with progression-free survival (PFS), prostate-specific antigen, and markers of bone turnover. Eighteen participants enrolled, and 17 underwent interpretable baseline (18)F-fluoride PET imaging before initiation of dasatinib. Twelve of 17 patients underwent on-treatment PET imaging. Statistically significant changes in response to dasatinib were identified by the SUVmaxavg (average of maximum standardized uptake value [SUVmax] for up to 5 tumors within the dynamic field of view) in bone metastases (P = 0.0002), with a significant differential (18)F-fluoride PET response between tumor and normal bone (P < 0.0001). Changes in (18)F-fluoride incorporation in bone metastases had borderline correlation with PFS by SUVmaxavg (hazard ratio, 0.91; 95% confidence interval, 0.82-1.00; P = 0.056). Changes by SUVmaxavg correlated with bone alkaline phosphatase (P = 0.0014) but not prostate-specific antigen (P = 0.47). This trial provides evidence of the ability (18)F-fluoride PET to delineate treatment response of dasatinib in CRPC bone

  7. Evaluation of a short dynamic 18F-fluoride PET/CT scanning method to assess bone metabolic activity in spinal orthopedics.

    PubMed

    Peters, Marloes J M; Wierts, Roel; Jutten, Elisabeth M C; Halders, Servé G E A; Willems, Paul C P H; Brans, Boudewijn

    2015-11-01

    A complication after spinal fusion surgery is pseudarthrosis, but its radiological diagnosis is of limited value. (18)F-fluoride PET with its ability to assess bone metabolism activity could be of value. The goal of this study was to assess the clinical feasibility of calculating the static standardized uptake value (SUV) from a short dynamic scan without the use of blood sampling, thereby obtaining all dynamic and static parameters in a scan of only 30 min. This approach was tested on a retrospective patient population with persisting pain after spinal fusion surgery. In 16 patients, SUVs (SUV max, SUV mean) and kinetic parameters (K 1, k 2, k 3, v b, K i,NLR, K 1/k 2, k 3/(k 2 + k 3), K i,patlak) were derived from static and dynamic PET/CT scans of operated and control regions of the spine, after intravenous administration of 156-214 MBq (18)F-fluoride. Parameter differences between control and operated regions, as well as between pseudarthrosis and fused segments were evaluated. SUVmean at 30 and 60 min was calculated from kinetic parameters obtained from the dynamic data set (SUV mean,2TCM). Agreement between measured and calculated SUVs was evaluated through Bland-Altman plots. Overall, statistically significant differences between control and operated regions were observed for SUV max, SUV mean, K i,NLR, K i,patlak, K 1/k 2 and k 3/(k 2 + k 3). Diagnostic CT showed pseudarthrosis in 6/16 patients, while in 10/16 patients, segments were fused. Of all parameters, only those regarding the incorporation of bone [K i,NLR, K i,patlak, k 3/(k 2 + k 3)] differed statistically significant in the intervertebral disc space between the pseudarthrosis and fused patients group. The mean values of the patient-specific blood clearance rate [Formula: see text] differed statistically significant between the pseudarthrosis and the fusion group, with a p value of 0.011. This may correspond with the lack of statistical significance of the SUV values between pseudarthrosis and

  8. Fluoride ion release and solubility of fluoride enriched interim cements.

    PubMed

    Lewinstein, Israel; Block, Jonathan; Melamed, Guy; Dolev, Eran; Matalon, Shlomo; Ormianer, Zeev

    2014-08-01

    Interim and definitive restorations cemented with interim cements for a prolonged interval are susceptible to bacterial infiltration and caries formation. The purpose of this in vitro study was to evaluate the long-term fluoride release and solubility of aged ZnO-based interim cements enriched separately with 0.4% NaF and SnF2. Four different brands of cements (Tempbond, Tempbond NE, Procem, and Freegenol) were tested for fluoride release and solubility. For every test, 6 disk specimens of each cement with NaF and SnF2, and 6 with no fluoride enrichment (control) were fabricated, for a total of 72 specimens. The disks were incubated in deionized water. Fluoride ion release was recorded at 1, 7, 14, 21, 63, 91, and 182 days. Solubility was calculated as weight percent after 90 days of incubation. The data were analyzed by analysis of variance with repeated measures and the Tukey honestly significant difference post hoc test (P<.05). Cements mixed with fluorides released fluoride ions for at least 182 days. Cements mixed with NaF released more fluoride ions than those mixed with SnF2 (P<.001). The cumulative release rates from all the tested cements mixed with either NaF or SnF2 were linear with respect to t(½) (r>.97), indicating a diffusion-controlled fluoride release. Cement and fluoride types were the main affecting factors in fluoride ion release. The addition of fluorides slightly increased the solubility of the cements. Given their long-term sustained and diffusive controlled release, these fluorides, particularly NaF when mixed with ZnO-based interim cements, may be useful for caries prevention under provisionally cemented restorations. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  9. Calcified peritoneal metastasis identified on 18F-fluoride positron emission tomography/computed tomography: Importance of extraosseous uptake of F-18 fluoride.

    PubMed

    Verma, Priyanka; Chandra, Piyush; Agrawal, Archi; Purandare, Nilendu; Shah, Sneha; Rangarajan, Venkatesh

    2016-01-01

    F-18 NaF positron emission tomography/computed tomography (PET/CT) is used for the evaluation of malignant and nonmalignant osseous disease. Extraosseous uptake of 18 fluoride-NaF has been observed in the arterial vasculature, gastrointestinal tract, and genitourinary tract. We describe a case of a woman with carcinoma of unknown primary in whom F-18 NaF PET/CT showed tracer uptake in the calcified peritoneal metastasis. Extraosseous findings on F-18 NaF PET/CT, though rare, may be visualized and may result in important management changes.

  10. Visual Pattern and Serial Quantitation of (18)F-Sodium Fluoride PET/CT in Asymptomatic Patients After Hip and Knee Arthroplasty.

    PubMed

    Son, Hye Joo; Jeong, Young Jin; Yoon, Hyun Jin; Wang, Lih; Kim, Hyeon Jun; Park, Jong-Hwan; Kang, Do-Young

    2016-12-01

    We investigated the visual tracer distribution pattern and serial changes in uptake ratio in different anatomical zones during the natural postoperative course in order to establish a reference for evaluation of patients with complications. A total of 36 patients without symptoms after hip or knee arthroplasty were grouped according to the interval between surgery and the scan. The serial changes in SUVmean in each periprosthetic zone were quantified using the volume of interest isocontour method. Images were classified according to the uptake distribution pattern. The uptake ratios in the postoperative period groups were then compared using the Kruskal-Wallis test. The correlation between uptake ratio and postoperative period was then determined. Tracer distribution patterns in hip prostheses were classified into three types and the patterns in knee prostheses into five types. In hip prostheses, intense osteoblastic activity was observed during 3-6 months and then declined in most patients, but showed a slight increase over 15-25 months in 5-10 % of patients. The correlation coefficients varied among the zones. Significant differences in uptake ratios among the period groups was found for all zones, except zone 8. Porous coated areas showed higher uptake than uncoated areas only for the period the 3-6 months. In knee prostheses, uptake ratios showed a curvilinear pattern, increasing from 3-6 to 8-15 months and declining later. The uptake ratios were different among the period groups. Every zone showed a positive correlation from 3-6 to 8-15 months, and negative correlations from 8-15 to 22-25 months. This is the first (18)F-sodium fluoride PET/CT study investigating the stability of implants and sets a reference for evaluation of patients with complications.

  11. Quantitative Assessment of Early [(18)F]Sodium Fluoride Positron Emission Tomography/Computed Tomography Response to Treatment in Men With Metastatic Prostate Cancer to Bone.

    PubMed

    Harmon, Stephanie A; Perk, Timothy; Lin, Christie; Eickhoff, Jens; Choyke, Peter L; Dahut, William L; Apolo, Andrea B; Humm, John L; Larson, Steven M; Morris, Michael J; Liu, Glenn; Jeraj, Robert

    2017-08-20

    Purpose [(18)F]Sodium fluoride (NaF) positron emission tomography (PET)/computed tomography (CT) is a promising radiotracer for quantitative assessment of bone metastases. This study assesses changes in early NaF PET/CT response measures in metastatic prostate cancer for correlation to clinical outcomes. Patients and Methods Fifty-six patients with metastatic castration-resistant prostate cancer (mCRPC) with osseous metastases had NaF PET/CT scans performed at baseline and after three cycles of chemotherapy (n = 16) or androgen receptor pathway inhibitors (n = 40). A novel technology, Quantitative Total Bone Imaging, was used for analysis. Global imaging metrics, including maximum standardized uptake value (SUVmax) and total functional burden (SUVtotal), were extracted from composite lesion-level statistics for each patient and tracked throughout treatment. Progression-free survival (PFS) was calculated as a composite end point of progressive events using conventional imaging and/or physician discretion of clinical benefit; NaF imaging was not used for clinical evaluation. Cox proportional hazards regression analyses were conducted between imaging metrics and PFS. Results Functional burden (SUVtotal) assessed midtreatment was the strongest univariable PFS predictor (hazard ratio, 1.97; 95% CI, 1.44 to 2.71; P < .001). Classification of patients based on changes in functional burden showed stronger correlation to PFS than did the change in number of lesions. Various global imaging metrics outperformed baseline clinical markers in predicting outcome, including SUVtotal and SUVmean. No differences in imaging response or PFS correlates were found for different treatment cohorts. Conclusion Quantitative total bone imaging enables comprehensive disease quantification on NaF PET/CT imaging, showing strong correlation to clinical outcomes. Total functional burden assessed after three cycles of hormonal therapy or chemotherapy was predictive of PFS for men with mCRPC. This

  12. Impact of (18)F-Fluoride PET on Intended Management of Patients with Cancers Other Than Prostate Cancer: Results from the National Oncologic PET Registry.

    PubMed

    Hillner, Bruce E; Siegel, Barry A; Hanna, Lucy; Duan, Fenghai; Shields, Anthony F; Quinn, Bruce; Coleman, R Edward

    2014-07-01

    The National Oncologic PET Registry prospectively assessed the impact of PET with (18)F-sodium fluoride (NaF PET) on intended management of Medicare patients with suspected or known osseous metastasis. We report our findings for cancers other than prostate and make selected comparisons to our previously reported prostate cancer cohort. Data were collected from both referring and interpreting physicians before and after NaF PET in patients (age ≥ 65 y) stratified for initial staging (IS; n = 570), for suspected first osseous metastasis (FOM; n = 1,814; breast, 781 [43%]; lung, 380 [21%]; and all other cancers, 653 [36%]), and for suspected progression of osseous metastasis (POM; n = 435). The dominant indication was bone pain. If NaF PET were unavailable, conventional bone scintigraphy would have been ordered in 85% of patients. In IS, 28% of patients had suspected or confirmed nonosseous metastasis. If neither conventional bone scintigraphy nor NaF PET were available, referring physicians would have ordered other advanced imaging more than 70% of the time rather than initiate treatment for suspected FOM (11%-16%) or POM (18%-22%). When intended management was classified as either treatment or nontreatment, the intended management change for each cancer type was highest in POM, lower in IS, and lowest in FOM. For suspected FOM, intended management change was lower in breast (24%), lung (36%), or other cancers (31%), compared with prostate cancer (44%) (P < 0.0001), but the NaF PET finding (normal/benign/equivocal, probable, or definite metastases) frequencies were similar across cancer types. After normal/benign/equivocal PET results, 15% of breast, 30% lung, and 38% prostate cancer patients had treatment, likely reflecting differences in management of nonosseous disease. For patients with definite metastasis on NaF PET, nonprostate, compared with prostate, cancer patients had post-PET plans for more frequent biopsy, alternative imaging, chemotherapy, and

  13. Do Fluoride Ions Protect Teeth?

    ERIC Educational Resources Information Center

    Parkin, Christopher

    1998-01-01

    Begins with the procedure and results from an investigation on the effect of fluoride on the reaction between eggshell (substitute teeth) and dilute ethanoic acid. Describes an elegantly modified and improvised apparatus. (DDR)

  14. Do Fluoride Ions Protect Teeth?

    ERIC Educational Resources Information Center

    Parkin, Christopher

    1998-01-01

    Begins with the procedure and results from an investigation on the effect of fluoride on the reaction between eggshell (substitute teeth) and dilute ethanoic acid. Describes an elegantly modified and improvised apparatus. (DDR)

  15. Differences in regional bone perfusion and turnover between lumbar spine and distal humerus: (18)F-fluoride PET study of treatment-naïve and treated postmenopausal women.

    PubMed

    Frost, Michelle L; Blake, Glen M; Cook, Gary J R; Marsden, Paul K; Fogelman, Ignac

    2009-11-01

    The functional imaging technique of (18)F-fluoride positron emission tomography ((18)F-PET) allows the non-invasive assessment of regional bone blood perfusion and turnover. Bone perfusion and turnover measured using (18)F-PET correlate closely with those obtained experimentally and so they can be readily applied in clinical research studies. The aim of this study was to compare bone perfusion and turnover between the lumbar spine and humerus in both treatment naïve postmenopausal women (n=11) and those on stable antiresorptive therapy (n=12). All women had a BMD T-score of less than -2 at the spine and/or hip. Each woman had a dynamic PET scan of the lumbar spine and distal humerus after injection of 90 MBq (18)F-fluoride. Using a three-compartmental model bone perfusion (K(1)), the net plasma clearance of tracer to bone mineral (K(i)) reflecting regional bone turnover and the rate constants k(2)-k(4) describing the transport of fluoride between plasma, an extravascular bone compartment and bone mineral compartment were calculated. Mean bone perfusion (K(1)) and bone turnover (K(i)) were significantly higher at the lumbar spine compared to the humerus for both treatment-naïve and antiresorptive groups. K(1) values were on average 3 times greater while K(i) was approximately 50% greater at the lumbar spine. The rate constant k(2), the reverse transport of fluoride from the extravascular compartment to plasma, was significantly lower at the humerus compared to the lumbar spine in both groups. The ratio K(i)/K(1) describing the unidirectional extraction efficiency to bone mineral was significantly greater at the humerus compared to the lumbar spine for both study groups. No significant differences between skeletal sites were observed for k(3) or k(4). In conclusion a significant skeletal heterogeneity was observed in terms of bone perfusion and turnover between the lumbar spine and humerus. (18)F-PET may aid in our understanding of the importance of bone perfusion

  16. First application of the Trojan horse method with a radioactive ion beam: Study of the 18F (p,α ) 15O reaction at astrophysical energies

    NASA Astrophysics Data System (ADS)

    Cherubini, S.; Gulino, M.; Spitaleri, C.; Rapisarda, G. G.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Romano, S.; Kubono, S.; Yamaguchi, H.; Hayakawa, S.; Wakabayashi, Y.; Iwasa, N.; Kato, S.; Komatsubara, T.; Teranishi, T.; Coc, A.; de Séréville, N.; Hammache, F.; Kiss, G.; Bishop, S.; Binh, D. N.

    2015-07-01

    Measurement of nuclear cross sections at astrophysical energies involving unstable species is one of the most challenging tasks in experimental nuclear physics. The use of indirect methods is often unavoidable in this scenario. In this paper the Trojan horse method is applied for the first time to a radioactive ion beam-induced reaction studying the 18F (p ,α )15O process at low energies relevant to astrophysics via the three-body reaction 2H (18F ,α15O ) n . The knowledge of the 18F (p,α ) 15O reaction rate is crucial to understand the nova explosion phenomena. The cross section of this reaction is characterized by the presence of several resonances in 19Ne and possibly interference effects among them. The results reported in literature are not satisfactory and new investigations of the 18F (p,α ) 15O reaction cross section will be useful. In the present work the spin-parity assignments of relevant levels have been discussed and the astrophysical S factor has been extracted considering also interference effects.

  17. The Determination of Atmospheric Fluoride with a Specific Ion Electrode

    NASA Technical Reports Server (NTRS)

    Feldstein, M.; Levaggi, D. A.

    1971-01-01

    Atmospheric fluoride is collected on lime-coated filter paper exposed to the ambient atmosphere for 30-day periods. The fluoride is eluted from the paper and analyzed with the use of a fluoride specific ion electrode. The technique permits evaluation of potential fluoride sources in terms of downwind concentrations and provides a simple, rapid procedure for the analysis of large numbers of samples.

  18. Comparative diagnostic value of 18F-fluoride PET-CT versus MRI for skull-base bone invasion in nasopharyngeal carcinoma.

    PubMed

    Le, Yali; Chen, Yu; Zhou, Fan; Liu, Guangfu; Huang, Zhanwen; Chen, Yue

    2016-10-01

    This study compared the diagnostic value of F-fluoride PET-computed tomography (PET-CT) and MRI in skull-base bone erosion in nasopharyngeal carcinoma (NPC) patients. A total of 93 patients with biopsy-confirmed NPC were enrolled, including 68 men and 25 women between 23 and 74 years of age. All patients were evaluated by both F-fluoride PET-CT and MRI, and the interval between the two imaging examinations was less than 20 days. The patients received no treatment either before or between scans. The studies were interpreted by two nuclear medicine physicians or two radiologists with more than 10 years of professional experience who were blinded to both the diagnosis and the results of the other imaging studies. The reference standard was skull-base bone erosion at a 20-week follow-up imaging study. On the basis of the results of the follow-up imaging studies, 52 patients showed skull-base bone erosion. The numbers of true positives, false positives, true negatives, and false negatives with F-fluoride PET-CT were 49, 4, 37, and 3, respectively. The numbers of true positives, false positives, true negatives, and false negatives with MRI were 46, 5, 36, and 6, respectively. The sensitivity, specificity, and crude accuracy of F-fluoride PET-CT were 94.23, 90.24, and 92.47%, respectively; for MRI, these values were 88.46, 87.80, and 88.17%. Of the 52 patients, 43 showed positive findings both on F-fluoride PET-CT and on MRI. Within the patient cohort, F-fluoride PET-CT and MRI detected 178 and 135 bone lesions, respectively. Both F-fluoride PET-CT and MRI have high sensitivity, specificity, and crude accuracy for detecting skull-base bone invasion in patients with NPC. F-fluoride PET-CT detected more lesions than did MRI in the skull-base bone. This suggests that F-fluoride PET-CT has a certain advantage in evaluating the skull-base bone of NPC patients. Combining the two methods could improve the diagnostic accuracy of skull-base bone invasion for NPC.

  19. Transport of 3-fluoro-L-α-methyl-tyrosine (FAMT) by organic ion transporters explains renal background in [(18)F]FAMT positron emission tomography.

    PubMed

    Wei, Ling; Tominaga, Hideyuki; Ohgaki, Ryuichi; Wiriyasermkul, Pattama; Hagiwara, Kohei; Okuda, Suguru; Kaira, Kyoichi; Kato, Yukio; Oriuchi, Noboru; Nagamori, Shushi; Kanai, Yoshikatsu

    2016-02-01

    A PET tracer for tumor imaging, 3-(18)F-l-α-methyl-tyrosine ([(18)F]FAMT), has advantages of high cancer-specificity and low physiological background. In clinical studies, FAMT-PET has been proved useful for the detection of malignant tumors and their differentiation from inflammation and benign lesions. The tumor specific uptake of FAMT is due to its high-selectivity to cancer-type amino acid transporter LAT1 among amino acid transporters. In [(18)F]FAMT PET, kidney is the only organ that shows high physiological background. To reveal transporters involved in renal accumulation of FAMT, we have examined [(14)C]FAMT uptake on the organic ion transporters responsible for the uptake into tubular epithelial cells. We have found that OAT1, OAT10 and OCTN2 transport [(14)C]FAMT. The [(14)C]FAMT uptake was inhibited by probenecid, furosemide and ethacrynic acid, consistent with the properties of the transporters. The amino acid uptake inhibitor, 2-amino-2-norbornanecarboxylic acid (BCH), also inhibited the [(14)C]FAMT uptake, whereas OCTN2-mediated [(14)C]FAMT uptake was Na(+)-dependent. We propose that FAMT uptake by OAT1, OAT10 and OCTN2 into tubular epithelial cells could contribute to the renal accumulation of FAMT. The results from this study would provide clues to the treatments to reduce renal background and enhance tumor uptake as well as to designing PET tracers with less renal accumulation.

  20. Synthesis of [18F]fallypride in a micro-reactor

    PubMed Central

    Lu, Shuiyu; Giamis, Anthony M.; Pike, Victor W.

    2008-01-01

    A commercial coiled-tube micro-reactor (NanoTek; Advion) was used as a convenient platform for the synthesis of [18F]fallypride in small doses (0.5–1.5 mCi) for micro-PET studies of brain dopamine subtype-2 receptors in rodents. Each radiosynthesis used low amounts (20–40 μg; 39–77 nmol) of tosylate precursor and [18F]fluoride ion (0.5–2.5 mCi). Optimization of the labeling reaction in the apparatus, with respect to the effects of precursor amount, reaction temperature, flow rate and [18F]fluoride ion to precursor ratio, was achieved rapidly and the decay-corrected radiochemical yield of [18F]fallypride (up to 88%) was reproducible. The low amounts of material used in each radiosynthesis allowed crude [18F]fallypride to be purified rapidly on an analytical-size reverse phase HPLC column, preceding formulation for intravenous injection. Scale-up of the reaction was easily achieved by continuously infusing reagent precursor solutions to obtain [18F]fallypride in much greater quantity. PMID:20047004

  1. Stereospecific approach to the synthesis of (/sup 18/F)12-deoxy-2-fluoro-D-mannose

    SciTech Connect

    Luxen, A.; Barrio, J.R.; Bida, G.T.; Satyamurthy, N.

    1985-05-01

    The reaction of methyl 4,6-O-benzylidene-3-O-benzyl-2-O- trifluoromethanesulfonyl-..beta..-D-glucopyranoside in acetonitrile at 75/sup 0/ for 30 min with (/sup 18/F)tetra-n-butylammonium fluoride, followed by silica gel column purification (di-chloromethane: acetone, 95:5) gave the corresponding (/sup 18/F) methyl 4,6-O-benzylidene-3-O-benzyl- 2-fluoro- ..beta.. -D-mannopyranoside with complete regio- and stereoselectivity (42% radiochemical yield). Hydrolysis of the radiolabeled fluoromannopyranoside intermediate with either 6N HCl or 50% methanesulfonic acid for 30 min at reflux, followed by purification by column chromatography (ion retardation, AG11A8 resin and neutral alumina) gave pure (/sup 18/F)2-deoxy-2-fluoro-D-mannose ((/sup 18/F) 2-FDM) suitable for human injection with a total radiochemical yield (from (/sup 18/F) fluoride ion) of 34%. Since chromatographic identification of 2-fluorodeoxyhexoses does not necessarily constitute a proof of chemical structure, unequivocal evidence of the identity of the final product was obtained using Fourier transform /sup 19/F-NMR. Samples with sufficient fluorine 19 mass when analyzed using /sup 19/F-NMR spectroscopy (Bruker WM-500, 470.56 MHz) after F-18 decay, showed only two peaks corresponding to the two anomers of 2-FDM (..cap alpha..=38.16, ..beta..=56.56; D/sub 2/O, solvent; C/sub 6/F/sub 6/, external reference; proton decoupled). The synthetic procedure described here permits the routine preparation of large amounts of (/sup 18/F)/sub 2/-FDM for tomographic studies. In this manner, comparisons of the biological and kinetic behavior of epimerically pure (/sup 18/F)2-deoxy-2-fluoro-D-glucose ((/sup 18/F)2-FDG) and (/sup 18/F)2-FDM in humans are now possible.

  2. Some electronic and magnetic properties of Fluoride ion in Fluoride structure nanocrystals

    NASA Astrophysics Data System (ADS)

    Imtani, Ali Nasir

    2012-01-01

    We have investigated the effects of the environment potential around Fluoride ion on some important electronic and magnetic properties such as dipole polarisability, moment of oscillator strengths S(k) and magnetic susceptibility. The theoretical procedure is based on the variational-perturbation theory with two parameter trial functions incorporated in an ionic model. We estimate these properties in four cases for Fluoride ion; free ion, ion under different potentials, ion in the crystals and ion in nanocrystal, CdF2, CaF2, PbF2, SrF2 and BaF2. Our results indicate that these properties vary with ion environments and the free state of Fluoride ion has higher values and there is linearity behaviour of these properties with lattice constant. For Fluoride ion in nanocrystal, we have found that there is an extra parameter that can also affect the dipole polarisability, the number of ions in the structure.

  3. Fluoride ion encapsulation by Mg2+ ions and phosphates in a fluoride riboswitch.

    PubMed

    Ren, Aiming; Rajashankar, Kanagalaghatta R; Patel, Dinshaw J

    2012-05-13

    Significant advances in our understanding of RNA architecture, folding and recognition have emerged from structure-function studies on riboswitches, non-coding RNAs whose sensing domains bind small ligands and whose adjacent expression platforms contain RNA elements involved in the control of gene regulation. We now report on the ligand-bound structure of the Thermotoga petrophila fluoride riboswitch, which adopts a higher-order RNA architecture stabilized by pseudoknot and long-range reversed Watson-Crick and Hoogsteen A•U pair formation. The bound fluoride ion is encapsulated within the junctional architecture, anchored in place through direct coordination to three Mg(2+) ions, which in turn are octahedrally coordinated to water molecules and five inwardly pointing backbone phosphates. Our structure of the fluoride riboswitch in the bound state shows how RNA can form a binding pocket selective for fluoride, while discriminating against larger halide ions. The T. petrophila fluoride riboswitch probably functions in gene regulation through a transcription termination mechanism.

  4. Fluoride ion encapsulation by Mg[superscript 2+] ions and phosphates in a fluoride riboswitch

    SciTech Connect

    Ren, Aiming; Rajashankar, Kanagalaghatta R.; Patel, Dinshaw J.

    2012-06-26

    Significant advances in our understanding of RNA architecture, folding and recognition have emerged from structure-function studies on riboswitches, non-coding RNAs whose sensing domains bind small ligands and whose adjacent expression platforms contain RNA elements involved in the control of gene regulation. We now report on the ligand-bound structure of the Thermotoga petrophila fluoride riboswitch, which adopts a higher-order RNA architecture stabilized by pseudoknot and long-range reversed Watson-Crick and Hoogsteen A {sm_bullet} U pair formation. The bound fluoride ion is encapsulated within the junctional architecture, anchored in place through direct coordination to three Mg{sup 2+} ions, which in turn are octahedrally coordinated to water molecules and five inwardly pointing backbone phosphates. Our structure of the fluoride riboswitch in the bound state shows how RNA can form a binding pocket selective for fluoride, while discriminating against larger halide ions. The T. petrophila fluoride riboswitch probably functions in gene regulation through a transcription termination mechanism.

  5. Effect of fluoride ion on the stability of DNA hairpin

    NASA Astrophysics Data System (ADS)

    Liu, Chao; Zhai, Weili; Gong, Hongling; Liu, Yanhui; Chen, Hu

    2017-06-01

    Fluoride prevents tooth decay as an additive in oral hygiene products, while high dose intake of fluoride from contaminated drinking water leads to fluorosis. Here we studied the effect of fluoride ion on the stability of DNA double helix using magnetic tweezers. The equilibrium critical force decreases with increasing concentration of fluoride in the range from 1 mM to 100 mM. Our results give the first quantitative measurement of DNA stability in the presence of fluoride ion, which might disturb DNA-related biological processes to cause fluorosis.

  6. 18F-Sodium Fluoride PET-CT Hybrid Imaging of the Lumbar Facet Joints: Tracer Uptake and Degree of Correlation to CT-graded Arthropathy

    PubMed Central

    Mabray, Marc C.; Brus-Ramer, Marcel; Behr, Spencer C.; Pampaloni, Miguel H.; Majumdar, Sharmila; Dillon, William P.; Talbott, Jason F.

    2016-01-01

    We aim to evaluate 18F-NaF uptake by facet joints with hybrid PET-CT technique. Specifically, we evaluate NaF uptake in the facet joints of the lower lumbar spine, and correlate with the morphologic grade of facet arthropathy on CT. 30 consecutive patients who underwent standard vertex to toes NaF PET-CT for re-staging of primary neoplastic disease without measurable or documented bony metastases were identified. Maximum (SUVmax) and average (SUVavg) standardized uptake values were calculated for each L3-4, L4-5, and L5-S1 facet joint (n = 180) and normalized to average uptake in the non-diseased femur. A Pathria grade (0-3) was assigned to each facet based upon the CT morphology. Spearman's rank correlation was performed for normalized SUVmax and SUVavg with Pathria grade. ANOVA was performed with Tukey-Kramer pairwise tests to evaluate differences in uptake between Pathria groups. Facet normalized SUVmax (r = 0.31, P < 0.001) and SUVavg (r = 0.28, P < 0.001) demonstrated a mild positive correlation with CT Pathria grade. There was a wide range of uptake values within each Pathria grade subgroup with statistically significant differences in uptake only between Pathria grade 3 as compared to grades 0, 1, and 2. In conclusion, NaF uptake and morphologic changes of the facet joint on CT are weakly correlated. Physiologic information provided by NaF uptake is often discrepant with structural findings on CT suggesting NaF PET may supplement conventional structural imaging for identification of pain generating facet joints. Prospective investigation into the relationship of facet joint NaF uptake with pain and response to pain interventions is warranted. PMID:27134557

  7. 3D skeletal uptake of (18)F sodium fluoride in PET/CT images is associated with overall survival in patients with prostate cancer.

    PubMed

    Lindgren Belal, Sarah; Sadik, May; Kaboteh, Reza; Hasani, Nezar; Enqvist, Olof; Svärm, Linus; Kahl, Fredrik; Simonsen, Jane; Poulsen, Mads H; Ohlsson, Mattias; Høilund-Carlsen, Poul F; Edenbrandt, Lars; Trägårdh, Elin

    2017-12-01

    Sodium fluoride (NaF) positron emission tomography combined with computer tomography (PET/CT) has shown to be more sensitive than the whole-body bone scan in the detection of skeletal uptake due to metastases in prostate cancer. We aimed to calculate a 3D index for NaF PET/CT and investigate its correlation to the bone scan index (BSI) and overall survival (OS) in a group of patients with prostate cancer. NaF PET/CT and bone scans were studied in 48 patients with prostate cancer. Automated segmentation of the thoracic and lumbar spines, sacrum, pelvis, ribs, scapulae, clavicles, and sternum were made in the CT images. Hotspots in the PET images were selected using both a manual and an automated method. The volume of each hotspot localized in the skeleton in the corresponding CT image was calculated. Two PET/CT indices, based on manual (manual PET index) and automatic segmenting using a threshold of SUV 15 (automated PET15 index), were calculated by dividing the sum of all hotspot volumes with the volume of all segmented bones. BSI values were obtained using a software for automated calculations. BSI, manual PET index, and automated PET15 index were all significantly associated with OS and concordance indices were 0.68, 0.69, and 0.70, respectively. The median BSI was 0.39 and patients with a BSI >0.39 had a significantly shorter median survival time than patients with a BSI <0.39 (2.3 years vs not reached after 5 years of follow-up [p = 0.01]). The median manual PET index was 0.53 and patients with a manual PET index >0.53 had a significantly shorter median survival time than patients with a manual PET index <0.53 (2.5 years vs not reached after 5 years of follow-up [p < 0.001]). The median automated PET15 index was 0.11 and patients with an automated PET15 index >0.11 had a significantly shorter median survival time than patients with an automated PET15 index <0.11 (2.3 years vs not reached after 5 years of follow-up [p < 0.001]). PET/CT indices

  8. Aromatic radiofluorination with (/sup 18/F)fluorine gas: 6-(/sup 18/F)fluoro-L-dopa

    SciTech Connect

    Firnau, G.; Chirakal, R.; Garnett, E.S.

    1984-11-01

    A new synthesis is described for the routine production of 3,4-dihydroxy-6-(/sup 18/F)fluoro-phenyl-L-alanine (6-(/sup 18/F)fluoro-L-dopa). The reaction between (/sup 18/F)fluorine gas and 3,4-dihydroxyphenyl-L-alanine (L-dopa) in liquid hydrogen fluoride gave 2-, 5-, and 6-(/sup 18/F)fluoro-L-dopa. 6-(/sup 18/F)Fluoro-L-dopa was isolated by reverse-phase high-pressure liquid chromatography. From 100 mCi (/sup 18/F)F/sub 2/, the method produces 3 mCi of 6-(/sup 18/F)fluoro-L-dopa at the end of synthesis.

  9. Ion release from, and fluoride recharge of a composite with a fluoride-containing bioactive glass

    PubMed Central

    Davis, Harry B.; Gwinner, Fernanda; Mitchell, John C.; Ferracane, Jack L.

    2014-01-01

    Objectives Materials that are capable of releasing ions such as calcium and fluoride, that are necessary for remineralization of dentin and enamel, have been the topic of intensive research for many years. The source of calcium has most often been some form of calcium phosphate, and that for fluoride has been one of several metal fluoride or hexafluorophosphate salts. Fluoride-containing bioactive glass (BAG) prepared by the sol-gel method acts as a single source of both calcium and fluoride ions in aqueous solutions. The objective of this investigation was to determine if BAG, when added to a composite formulation, can be used as a single source for calcium and fluoride ion release over an extended time period, and to determine if the BAG-containing composite can be recharged upon exposure to a solution of 5,000 ppm fluoride. Methods BAG 61 (61% Si; 31% Ca; 4% P; 3% F; 1% B) and BAG 81 (81% Si; 11% Ca; 4% P; 3% F; 1% B) were synthesized by the sol gel method. The composite used was composed of 50/50 Bis-GMA/TEGDMA, 0.8% EDMAB, 0.4% CQ, and 0.05% BHT, combined with a mixture of BAG (15%) and strontium glass (85%) to a total filler load of 72% by weight. Disks were prepared, allowed to age for 24 h, abraded, then placed into DI water. Calcium and fluoride release was measured by atomic absorption spectroscopy and fluoride ion selective electrode methods, respectively, after 2, 22, and 222 h. The composite samples were then soaked for 5 min in an aqueous 5,000 ppm fluoride solution, after which calcium and fluoride release was again measured at 2, 22, and 222 h time points. Results Prior to fluoride recharge, release of fluoride ions was similar for the BAG 61 and BAG 81 composites after 2 h, and also similar after 22 h. At the four subsequent time points, one prior to, and three following fluoride recharge, the BAG 81 composite released significantly more fluoride ions (p<0.05). Both composites were recharged by exposure to 5,000 ppm fluoride, although the BAG 81

  10. Comparative uptake of fluoride ion into enamel from various topical fluorides in vitro.

    PubMed

    Pai, N; McIntyre, J; Tadic, N; Laparidis, C

    2007-03-01

    There are many forms of topical fluoride available today, making the decision as to which is most effective to manage the immediate caries risk problem at hand, very difficult. The objective of this project was to determine the concentration and pattern of fluoride ion uptake into enamel from a variety of categories of topical fluoride recently available in Australia. Extracted, intact molar teeth were sectioned to provide six plates of smooth surface enamel. Windows of enamel 2 x 6 mm were exposed to a variety of topical fluorides for periods simulating those used in vivo. Following drying, the slates of enamel were exposed to 2 ml of 0.1 M HCl as a chemical biopsy agent for incremental periods of time. The concentrations of fluoride ion in the biopsy solutions for both test and background (control) slates of enamel were determined directly using a fluoride combination selective electrode in conjunction with a high impedance pH meter. Cumulative amounts of fluoride were determined for each topical fluoride agent. The concentrations of fluoride ion taken up into enamel were generally proportional to those present in each agent. However, those from APF gel greatly exceeded the amounts taken up from NaF gel. Also, the concentrations taken up from some of the highly concentrated metal fluorides were surprisingly low. Prior etching of enamel increased uptake and prolonged application of APF gel provided no extra benefit. Some topical fluorides, e.g., APF gel, provided a greatly increased uptake and to a greater depth than other self-application products. However, the frequency of its use should be considered with caution where patients have glass-based restorations.

  11. Measurement of the astrophysical S-factor for the {sup 18}F(p,{alpha}) reaction at E = 662 keV/u with a {sup 18}F radioactive beam

    SciTech Connect

    Rehm, K.E.; Blumenthal, D.J.; Gehring, J.

    1995-08-01

    {sup 18}F is produced in stars during the so-called breakout from the hot CNO cycle and is important as one of the links connecting the HCNO cycle with the rp-process by producing {sup 19}Ne via the {sup 18}F(p,{gamma}) reaction. There is, however, a competing reaction {sup 18}F(p,{alpha}){sup 15}O which leads back into the CNO cycle. The importance of {sup 18}F for producing {sup 19}Ne therefore depends strongly on the (p,{gamma}) to (p,{alpha}) cross sections ratio. We have begun to study the {sup 18}F(p,{alpha}){sup 15}O reaction using a {sup 18}F beam. {sup 18}F, which is a well-studied PET isotope, is generated at the medical cyclotron of the University of Wisconsin. Aqueous [{sup 18}F] fluoride ions are produced via the {sup 18}O(p,n){sup 18}F reaction using a 30-{mu}A, 11.4-MeV proton beam bombarding a 95% enriched [{sup 18}O] water target and electroplated onto the end of a 3-mm diameter Al anode. After electroplating, the anodized Al is pressed into a copper cathode insert for the National Electrostatics Corporation SNICS ion source, transported to Argonne National Laboratory and installed in the ion source of the Tandem accelerator at ATLAS. With an activity at the end of the electroplating process of 530 mCi, the starting activity after 2 h, which is the time needed to transport and install the material in the SNICS source, was 250 mCi, corresponding to a total number of {sup 18}F atoms of 8.8 x 10{sup 13}.

  12. Enhanced copper-mediated (18)F-fluorination of aryl boronic esters provides eight radiotracers for PET applications.

    PubMed

    Preshlock, Sean; Calderwood, Samuel; Verhoog, Stefan; Tredwell, Matthew; Huiban, Mickael; Hienzsch, Antje; Gruber, Stefan; Wilson, Thomas C; Taylor, Nicholas J; Cailly, Thomas; Schedler, Michael; Collier, Thomas Lee; Passchier, Jan; Smits, René; Mollitor, Jan; Hoepping, Alexander; Mueller, Marco; Genicot, Christophe; Mercier, Joël; Gouverneur, Véronique

    2016-06-28

    [(18)F]FMTEB, [(18)F]FPEB, [(18)F]flumazenil, [(18)F]DAA1106, [(18)F]MFBG, [(18)F]FDOPA, [(18)F]FMT and [(18)F]FDA are prepared from the corresponding arylboronic esters and [(18)F]KF/K222 in the presence of Cu(OTf)2py4. The method was successfully applied using three radiosynthetic platforms, and up to 26 GBq of non-carrier added starting activity of (18)F-fluoride.

  13. Synthesis of high specific activity (+)- and (-)-6-( sup 18 F)fluoronorepinephrine via the nucleophilic aromatic substitution reaction

    SciTech Connect

    Ding, Y.S.; Fowler, J.S.; Gatley, S.J.; Dewey, S.L.; Wolf, A.P. )

    1991-02-01

    The first example of a no-carrier-added {sup 18}F-labeled catecholamine, 6-({sup 18}F)fluoronorepinephrine (6-({sup 18}F)FNE), has been synthesized via nucleophilic aromatic substitution. The racemic mixture was resolved on a chiral HPLC column to obtain pure samples of (-)-6-({sup 18}F)FNE and (+)6-({sup 18}F)FNE. Radiochemical yields of 20% at the end of bombardment (EOB) for the racemic mixture (synthesis time 93 min), 6% for each enantiomer (synthesis time 128 min) with a specific activity of 2-5 Ci/mumol at EOB were obtained. Chiral HPLC peak assignment for the resolved enantiomers was achieved by using two independent methods: polarimetric determination and reaction with dopamine beta-hydroxylase. Positron emission tomography (PET) studies with racemic 6-({sup 18}F)FNE show high uptake and retention in the baboon heart. This work demonstrates that nucleophilic aromatic substitution by ({sup 18}F)fluoride ion is applicable to systems having electron-rich aromatic rings, leading to high specific activity radiopharmaceuticals. Furthermore, the suitably protected dihydroxynitrobenzaldehyde 1 may serve as a useful synthetic precursor for the radiosynthesis of other complex {sup 18}F-labeled radiotracers.

  14. No-carrier-added nucleophilic 18F-labelling in an electrochemical cell exemplified by the routine production of [18F]altanserin.

    PubMed

    Hamacher, K; Coenen, H H

    2006-09-01

    A new type of electrochemical cell with anodic deposition of no-carrier-added [(18)F]fluoride and variable reaction volume has been developed. The reactor is designed for small reaction volumes and non-thermal drying of [(18)F]fluoride. The implementation of this reactor into a complete remotely controlled synthesis device is described for the routine production of [(18)F]altanserin. A radiochemical yield of 23+/-5% was obtained via cryptate-mediated nucleophilic (18)F-fluorination. Batches of up to 6 GBq [(18)F]altanserin, suitable for human application, with a molar activity of >500 GBq/micromol were obtained within 75 min.

  15. Single-step High-yield Radiosynthesis and Evaluation of a Sensitive 18F-Labeled Ligand for Imaging Brain Peripheral Benzodiazepine Receptors with PET

    PubMed Central

    Briard, Emmanuelle; Zoghbi, Sami S.; Siméon, Fabrice G.; Imaizumi, Masao; Gourley, Jonathan P.; Shetty, H. Umesha; Lu, Shuiyu; Fujita, Masahiro; Innis, Robert B.; Pike, Victor W.

    2009-01-01

    Elevated levels of peripheral benzodiazepine receptors (PBR) are associated with activated microglia in their response to inflammation. Hence, PBR imaging in vivo is valuable for investigating brain inflammatory conditions. Sensitive, easily prepared and readily available radioligands for imaging with positron emission tomography (PET) are desirable for this purpose. We describe a new 18F-labeled PBR radioligand, namely [18F]N-fluoroacetyl-N-(2,5-dimethoxybenzyl)-2-phenoxyaniline ([18F]9). [18F]9 was produced easily through a single and highly efficient step, the reaction of [18F]fluoride ion with the corresponding bromo precursor, 8. Ligand 9 exhibited high affinity for PBR in vitro. PET showed that [18F]9 was avidly taken into monkey brain and gave a high ratio of PBR-specific to nonspecific binding. [18F]9 was devoid of defluorination in rat and monkey and gave predominantly polar radiometabolite(s). In rat, a low level radiometabolite of intermediate lipophilicity was identified as [18F]2-fluoro-N-(2-phenoxyphenyl)acetamide ([18F]11). [18F]9 is a promising radioligand for future imaging of PBR in living human brain. PMID:19119848

  16. Toxic fluoride gas emissions from lithium-ion battery fires.

    PubMed

    Larsson, Fredrik; Andersson, Petra; Blomqvist, Per; Mellander, Bengt-Erik

    2017-08-30

    Lithium-ion battery fires generate intense heat and considerable amounts of gas and smoke. Although the emission of toxic gases can be a larger threat than the heat, the knowledge of such emissions is limited. This paper presents quantitative measurements of heat release and fluoride gas emissions during battery fires for seven different types of commercial lithium-ion batteries. The results have been validated using two independent measurement techniques and show that large amounts of hydrogen fluoride (HF) may be generated, ranging between 20 and 200 mg/Wh of nominal battery energy capacity. In addition, 15-22 mg/Wh of another potentially toxic gas, phosphoryl fluoride (POF3), was measured in some of the fire tests. Gas emissions when using water mist as extinguishing agent were also investigated. Fluoride gas emission can pose a serious toxic threat and the results are crucial findings for risk assessment and management, especially for large Li-ion battery packs.

  17. Ion release from calcium and fluoride containing dental varnishes.

    PubMed

    Cochrane, N J; Shen, P; Yuan, Y; Reynolds, E C

    2014-03-01

    A range of dental varnishes have been commercialized recently that contain calcium and inorganic phosphate in addition to fluoride. The aim of this study was to analyse the fluoride, calcium and inorganic phosphate ion release from: (1) MI Varnish containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP); (2) Clinpro White containing functionalized tricalcium phosphate (fTCP); (3) Enamel Pro containing amorphous calcium phosphate; (4) Bifluorid 5 containing calcium fluoride; and (5) Duraphat (no added calcium control). The varnishes were applied to a standardized surface area of polyvinyl chloride (n = 7 per group) and immersed in 25 g of distilled deionized water which was changed at 1, 4, 24, 72 and 168 hours. The ion release was determined by ion chromatography and expressed as μmol (cumulative) per gram of varnish. All varnishes released measurable fluoride and calcium, however only MI Varnish and Enamel Pro released significant levels of inorganic phosphate. At 24 hours the order of cumulative fluoride release was: 1>3>4>2=5 with 1 significantly higher (p < 0.05) than the rest. At 72 and 168 hours, the cumulative calcium release was: 1>4>3>2=5 with 1 significantly higher (p < 0.05) than the rest. MI Varnish containing CPP-ACP had the highest release of calcium and fluoride ions. © 2014 Australian Dental Association.

  18. Solid electrolytes for fluoride ion batteries: ionic conductivity in polycrystalline tysonite-type fluorides.

    PubMed

    Rongeat, Carine; Reddy, M Anji; Witter, Raiker; Fichtner, Maximilian

    2014-02-12

    Batteries based on a fluoride shuttle (fluoride ion battery, FIB) can theoretically provide high energy densities and can thus be considered as an interesting alternative to Li-ion batteries. Large improvements are still needed regarding their actual performance, in particular for the ionic conductivity of the solid electrolyte. At the current state of the art, two types of fluoride families can be considered for electrolyte applications: alkaline-earth fluorides having a fluorite-type structure and rare-earth fluorides having a tysonite-type structure. As regard to the latter, high ionic conductivities have been reported for doped LaF3 single crystals. However, polycrystalline materials would be easier to implement in a FIB due to practical reasons in the cell manufacturing. Hence, we have analyzed in detail the ionic conductivity of La(1-y)Ba(y)F(3-y) (0 ≤ y ≤ 0.15) solid solutions prepared by ball milling. The combination of DC and AC conductivity analyses provides a better understanding of the conduction mechanism in tysonite-type fluorides with a blocking effect of the grain boundaries. Heat treatment of the electrolyte material was performed and leads to an improvement of the ionic conductivity. This confirms the detrimental effect of grain boundaries and opens new route for the development of solid electrolytes for FIB with high ionic conductivities.

  19. Removal of fluoride ion by bone char produced from animal biomass.

    PubMed

    Kawasaki, Naohito; Ogata, Fumihiko; Tominaga, Hisato; Yamaguchi, Isao

    2009-01-01

    Bone char (BC) was prepared by carbonizing four types of animal biomass, and the adsorption of fluoride ions and elution of phosphate ions were investigated. It was found that the BC yield decreased as carbonization temperature increased, and that carbonization temperature had no significant effect on surface pH, base or acid consumptions. Fluoride ion adsorption was increased in BC produced at a low carbonization temperature. The adsorption mechanism of fluoride ion on BCs might be monolayer adsorption. BC can potentially be used to remove fluoride ions in drinking water. However, it was found that phosphate ions from BC are eluted due to adsorption of fluoride ions, and that ingestion of large amounts of phosphate ions inhibits reabsorption of calcium in the human body. Thus there is a need to study the elution behavior of phosphate ions. The adsorption mechanisms of fluoride ions onto BC would be a physical adsorption onto BC and phosphate ion in BC is exchanged to fluoride ion.

  20. Fluoride ion encapsulation by Mg2+ and phosphates in a fluoride riboswitch

    PubMed Central

    Ren, Aiming; Rajashankar, Kanagalaghatta R.; Patel, Dinshaw J.

    2012-01-01

    Significant advances in our understanding of RNA architecture, folding and recognition have emerged from structure-function studies on riboswicthes, non-coding RNAs whose sensing domains bind small ligands and whose adjacent expression platforms contain RNA elements involved in the control of gene regulation. We now report on the ligand-bound structure of the Thermotoga petrophila fluoride riboswitch, which adopts a higher-order RNA architecture stabilized by pseudoknot and long-range reversed Watson-Crick and Hoogsteen A•U pair formation. The bound fluoride ion is encapsulated within the junctional architecture, anchored in place through direct coordination to three Mg2+ ions, which in turn are octahedrally coordinated to waters and five inwardly-pointing backbone phosphates. Our structure of the fluoride riboswitch in the bound state defines how RNA can form a binding pocket selective for fluoride, while discriminating against larger halide ions. The T. petrophila fluoride riboswitch most likely functions in gene regulation through a transcription termination mechanism. PMID:22678284

  1. Fluoride ion recognition by chelating and cationic boranes.

    PubMed

    Hudnall, Todd W; Chiu, Ching-Wen; Gabbaï, François P

    2009-02-17

    Because of the ubiquity of fluoride ions and their potential toxicity at high doses, researchers would like to design receptors that selectively detect this anion. Fluoride is found in drinking water, toothpaste, and osteoporosis drugs. In addition, fluoride ions also can be detected as an indicator of uranium enrichment (via hydrolysis of UF(6)) or of the chemical warfare agent sarin, which releases the ion upon hydrolysis. However, because of its high hydration enthalpy, the fluoride anion is one of the most challenging targets for anion recognition. Among the various recognition strategies that are available, researchers have focused a great deal of attention on Lewis acidic boron compounds. These molecules typically interact with fluoride anions to form the corresponding fluoroborate species. In the case of simple triarylboranes, the fluoroborates are formed in organic solvents but not in water. To overcome this limitation, this Account examines various methods we have pursued to increase the fluoride-binding properties of boron-based receptors. We first considered the use of bifunctional boranes, which chelate the fluoride anion, such as 1,8-diborylnaphthalenes or heteronuclear 1-boryl-8-mercurio-naphthalenes. In these molecules, the neighboring Lewis acidic atoms can cooperatively interact with the anionic guest. Although the fluoride binding constants of the bifunctional compounds exceed those of neutral monofunctional boranes by several orders of magnitude, the incompatibility of these systems with aqueous media limits their utility. More recently, we have examined simple triarylboranes whose ligands are decorated by cationic ammonium or phosphonium groups. These cationic groups increase the electrophilic character of these boranes, and unlike their neutral analogs, they are able to complex fluoride in aqueous media. We have also considered cationic boranes, which form chelate complexes with fluoride anions. Our work demonstrates that Coulombic and chelate

  2. Novel fluorogenic probe for fluoride ion based on the fluoride-induced cleavage of tert-butyldimethylsilyl ether

    NASA Astrophysics Data System (ADS)

    Yang, Xiao-Feng

    2007-06-01

    A highly sensitive and selective fluorogenic probe for fluoride ion, 4-methylumbelliferyl tert-butyldimethylsilyl ether (4-MUTBS), was designed and synthesized. 4-MUTBS was a weakly fluorescent compound and was synthesized via the one-step reaction of 4-MU with tert-butyldimethylsilyl chloride. Upon incubation with fluoride ion in acetone-water solution (7:3, v/v), the Si-O bond of 4-MUTBS was cleaved and highly fluorescent 4-methylumbelliferone (4-MU) was released, hence leading to the fluorescence increase of the reaction solution. The fluorescence increase is linearly with fluoride concentration in the range 50-8000 nmol l -1 with a detection limit of 19 nmol l -1 (3 σ). Because of the high affinity of silicon toward fluoride ion, the proposed probe shows excellent selectivity toward fluoride ion over other anions. The method has been successfully applied to the fluoride determination in toothpaste and tap water samples.

  3. Removal of fluoride ions from aqueous solution by waste mud.

    PubMed

    Kemer, Baris; Ozdes, Duygu; Gundogdu, Ali; Bulut, Volkan N; Duran, Celal; Soylak, Mustafa

    2009-09-15

    The present study was carried out to assess the ability of original waste mud (o-WM) and different types of activated waste mud which are acid-activated (a-WM) and precipitated waste mud (p-WM), in order to remove excess of fluoride from aqueous solution by using batch technique. The p-WM exhibited greater performance than the others. Adsorption studies were conducted as a function of pH, contact time, initial fluoride concentration, adsorbent concentration, temperature, etc. Studies were also performed to understand the effect of some co-existing ions present in aqueous solutions. Adsorption process was found to be almost independent of pH for all types of waste mud. Among the kinetic models tested for p-WM, pseudo-second-order model fitted the kinetic data well with a perfect correlation coefficient value of 1.00. It was found that the adequate time for the adsorption equilibrium of fluoride was only 1h. Thermodynamic parameters including the Gibbs free energy (DeltaG degrees ), enthalpy (DeltaH degrees ), and entropy (DeltaS degrees ) revealed that adsorption of fluoride ions on the p-WM was feasible, spontaneous and endothermic in the temperature range of 0-40 degrees C. Experimental data showed a good fit with the Langmuir and Freundlich adsorption isotherm models. Results of this study demonstrated the effectiveness and feasibility of WM for removal of fluoride ions from aqueous solution.

  4. Method for selective recovery of PET-usable quantities of [.sup.18 F] fluoride and [.sup.13 N] nitrate/nitrite from a single irradiation of low-enriched [.sup.18 O] water

    DOEpatents

    Ferrieri, Richard A.; Schlyer, David J.; Shea, Colleen

    1995-06-13

    A process for simultaneously producing PET-usable quantities of [.sup.13 N]NH.sub.3 and [.sup.18 F]F.sup.- for radiotracer synthesis is disclosed. The process includes producing [.sup.13 N]NO.sub.2.sup.- /NO.sub.3.sup.- and [.sup.18 F]F.sup.- simultaneously by exposing a low-enriched (20%-30%) [.sup.18 O]H.sub.2 O target to proton irradiation, sequentially isolating the [.sup.13 N]NO.sub.2.sup.- /NO.sub.3.sup.- and [.sup.18 F]F.sup.- from the [.sup.18 O]H.sub.2 O target, and reducing the [.sup.13 N]NO.sub.2.sup.- /NO.sub.3.sup.- to [.sup.13 N]NH.sub.3. The [.sup.13 N]NH.sub.3 and [.sup.18 F]F.sup.- products are then conveyed to a laboratory for radiotracer applications. The process employs an anion exchange resin for isolation of the isotopes from the [.sup.18 O]H.sub.2 O, and sequential elution of [.sup.13 N]NO.sub.2.sup.- /NO.sub.3.sup.- and [ .sup.18 F]F.sup.- fractions. Also the apparatus is disclosed for simultaneously producing PET-usable quantities of [.sup.13 N]NH.sub.3 and [.sup.18 F]F.sup.- from a single irradiation of a single low-enriched [.sup.18 O]H.sub.2 O target.

  5. Method for selective recovery of PET-usable quantities of [{sup 18}F] fluoride and [{sup 13}N] nitrate/nitrite from a single irradiation of low-enriched [{sup 18}O] water

    DOEpatents

    Ferrieri, R.A.; Schlyer, D.J.; Shea, C.

    1995-06-13

    A process for simultaneously producing PET-usable quantities of [{sup 13}N]NH{sub 3} and [{sup 18}F]F{sup {minus}} for radiotracer synthesis is disclosed. The process includes producing [{sup 13}N]NO{sub 2}{sup {minus}}/NO{sub 3}{sup {minus}}and [{sup 18}F]F{sup {minus}} simultaneously by exposing a low-enriched (20%-30%) [{sup 18}O]H{sub 2}O target to proton irradiation, sequentially isolating the [{sup 13}N]NO{sub 2}{sup {minus}}/NO{sub 3}{sup {minus}} and [{sup 18}F]F{sup {minus}} from the [{sup 18}O]H{sub 2}O target, and reducing the [{sup 13}N]NO{sub 2}{sup {minus}}/NO{sub 3}{sup {minus}} to [{sup 13}N]NH{sub 3}. The [{sup 13}N]NH{sub 3} and [{sup 18}F]F{sup {minus}} products are then conveyed to a laboratory for radiotracer applications. The process employs an anion exchange resin for isolation of the isotopes from the [{sup 18}O]H{sub 2}O, and sequential elution of [{sup 13}N]NO{sub 2}{sup {minus}}/NO{sub 3}{sup {minus}} and [{sup 18}F]F{sup {minus}} fractions. Also the apparatus is disclosed for simultaneously producing PET-usable quantities of [{sup 13}N]NH{sub 3} and [{sup 18}F]F{sup {minus}} from a single irradiation of a single low-enriched [{sup 18}O]H{sub 2}O target. 2 figs.

  6. Fluoride and aluminum release from restorative materials using ion chromatography

    PubMed Central

    OKTE, Zeynep; BAYRAK, Sule; FIDANCI, Ulvi Reha; SEL, Tevhide

    2012-01-01

    Objective The aim of this study was to determine the amounts of fluoride and aluminum released from different restorative materials stored in artificial saliva and double-distilled water. Material and Methods Cylindrical specimens (10 x 1 mm) were prepared from 4 different restorative materials (Kavitan Plus, Vitremer, Dyract Extra, and Surefil). For each material, 20 specimens were prepared, 10 of which were stored in 5 mL artificial saliva and 10 of which were stored in 5 mL of double-distilled water. Concentrations of fluoride and aluminum in the solutions were measured using ion chromatography. Measurements were taken daily for one week and then weekly for two additional weeks. Data were analyzed using two-way ANOVA and Duncan's multiple range tests (p<0.05). Results The highest amounts of both fluoride and aluminum were released by the resin-modified glass ionomer cement Vitremer in double-distilled water (p<0.05). All materials released significantly more fluoride in double-distilled water than in artificial saliva (p<0.05). In artificial saliva, none of the materials were observed to release aluminum. Conclusion It was concluded that storage media and method of analysis should be taken into account when the fluoride and aluminum release from dental materials is assessed. PMID:22437674

  7. Investigating the Intercalation Chemistry of Alkali Ions in Fluoride Perovskites

    DOE PAGES

    Yi, Tanghong; Chen, Wei; Cheng, Lei; ...

    2017-01-20

    Reversible intercalation reactions provide the basis for modern battery electrodes. In spite of the decades of exploration of electrode materials, the potential for materials in the nonoxide chemical space with regards to intercalation chemistry is vast and rather untested. Transition metal fluorides stand out as an obvious target. To this end, we report herein a new family of iron fluoride-based perovskite cathode materials AxK1–xFeF3 (A = Li, Na). By starting with KFeF3, approximately 75% of K+ ions were subsequently replaced by Li+ and Na+ through electrochemical means. X-ray diffraction and Fe X-ray absorption spectroscopy confirmed the existence of intercalation ofmore » alkali metal ions in the perovskite structure, which is associated with the Fe2+/3+ redox couple. A computational study by density functional theory showed agreement with the structural and electrochemical data obtained experimentally, which suggested the possibility of fluoride-based materials as potential intercalation electrodes. Our study increases our understanding of the intercalation chemistry of ternary fluorides, which could inform efforts toward the exploration of new electrode materials.« less

  8. Fluoride

    MedlinePlus

    ... by teeth and helps to strengthen teeth, resist acid, and block the cavity-forming action of bacteria. Fluoride usually is prescribed for children and adults whose homes have water that is not fluoridated (already has fluoride added). ...

  9. Adsorption of fluoride, phosphate, and arsenate ions on a new type of ion exchange fiber.

    PubMed

    Ruixia, Liu; Jinlong, Guo; Hongxiao, Tang

    2002-04-15

    A new type of ion exchange fiber for the removal of fluoride, phosphate, and arsenate ions has been developed. A batch adsorption technique for investigating adsorption kinetic and equilibrium parameters and determining pH adsorption edges is applied. It is shown that the adsorption properties of the ion exchange fiber for fluoride, phosphate, and arsenate ions depend on the pH value and anion concentration. The adsorption of arsenate on the sorbent reaches a maximum of 97.9% in the pH value range of 3.5 to 7.0. The adsorption percentage of phosphate is more than 99% in the pH range of 3.0 to 5.5. The adsorption of fluoride on the ion exchange fiber is found to be 90.4% at pH 3.0. The Freundlich model can describe the adsorption equilibrium data of fluoride, arsenate, and phosphate anions. The sorption of the three anions on the ion exchange fiber is a rapid process, and the adsorption kinetic data can be simulated very well by the pseudo-second-order rate equation. The column performance is carried out to assess the applicability of the ion exchange fiber for the removal of fluoride, phosphate, and arsenate ions from synthetic wastewaters with satisfactory removal efficiency. The desorption experiment shows that fluoride ion sorbed by the fiber column can be quantitatively desorbed with 5 mL of 0.50 mol/L NaOH at elution rate of 1 mL/min, and 30 mL of NaOH is necessary for the quantitative recovery of phosphate and arsenate ions.

  10. Sources of carrier F-19 in F-18 fluoride

    SciTech Connect

    Link, J. M.; Shoner, S. C.; Krohn, K. A.

    2012-12-19

    Fluorine-18 is used for many PET radiopharmaceuticals. Theoretically {sup 18}F should be carrier free and a good candidate for nanochemistry. However, {sup 18}F has 10 to 1000 times more stable fluorine atoms than radioactive atoms. In order to understand the source of carrier fluoride and other ions associated with {sup 18}F radiosynthesis, anion concentrations of different components of {sup 18}F target systems as well as solvents and chemicals used in radiosynthesis were measured. Results: The enriched water used for production of {sup 18}F had low levels of anions. In general, the sources of anions, particularly of fluoride, were the chemical reagents used for synthesis and trace contaminants in tubing, valves and fittings. A major component of contamination was nitrate from irradiation of dissolved nitrogen gas in the target water.

  11. Sources of carrier F-19 in F-18 fluoride

    NASA Astrophysics Data System (ADS)

    Link, J. M.; Shoner, S. C.; Krohn, K. A.

    2012-12-01

    Fluorine-18 is used for many PET radiopharmaceuticals. Theoretically 18F should be carrier free and a good candidate for nanochemistry. However, 18F has 10 to 1000 times more stable fluorine atoms than radioactive atoms. In order to understand the source of carrier fluoride and other ions associated with 18F radiosynthesis, anion concentrations of different components of 18F target systems as well as solvents and chemicals used in radiosynthesis were measured. Results: The enriched water used for production of 18F had low levels of anions. In general, the sources of anions, particularly of fluoride, were the chemical reagents used for synthesis and trace contaminants in tubing, valves and fittings. A major component of contamination was nitrate from irradiation of dissolved nitrogen gas in the target water.

  12. Simple preparation of new [(18) F]F-labeled synthetic amino acid derivatives with two click reactions in one-pot and SPE purification.

    PubMed

    Yook, Cheol-Min; Lee, Sang Ju; Oh, Seung Jun; Ha, Hyun-Joon; Lee, Jong Jin

    2015-06-30

    New [(18) F]fluorinated 1,2,3-triazolyl amino acid derivatives were efficiently prepared from Huisgen 1,3-dipolar cycloaddition reactions, well known as click reaction. We developed two simultaneous click reactions in one-pot with a simple solid-phase extraction (SPE) purification method. [(18) F]fluoro-1-propyne was obtained at a 45% non-decay corrected radiochemical yield based on the [(18) F]fluoride ion. The one-pot and simultaneous two click reactions were performed with unprotected azido-alkyl amino acid, [(18) F]fluoro-1-propyne, and lipophilic additive alkyne to produce three synthetic amino acid derivatives, AMC-101 ([(18) F]-6a), AMC-102 ([(18) F]-6b), and AMC-103 ([(18) F]-6c) with 29%, 28%, and 24% of non-decay corrected radiochemical yields, respectively. All radiotracers indicated that radiochemical purities were >95% without any residual organic solvent. Our new method involving two click reactions in one-pot showed high radiochemical and chemical purity by easy removal of the residual precursor from the simultaneous two click reactions. Copyright © 2015 John Wiley & Sons, Ltd.

  13. One-step 18F labeling of biomolecules using organotrifluoroborates

    PubMed Central

    Liu, Zhibo; Lin, Kuo-Shyan; Bénard, François; Pourghiasian, Maral; Kiesewetter, Dale O; Perrin, David M; Chen, Xiaoyuan

    2017-01-01

    Herein we present a general protocol for the functionalization of biomolecules with an organotrifluoroborate moiety so that they can be radiolabeled with aqueous 18F fluoride (18F−) and used for positron emission tomography (PET) imaging. Among the β+-emitting radionuclides, fluorine-18 (18F) is the isotope of choice for PET, and it is produced, on-demand, in many hospitals worldwide. Organotrifluoroborates can be 18F-labeled in one step in aqueous conditions via 18F–19F isotope exchange. This protocol features a recently designed ammoniomethyltrifluoroborate, and it describes the following: (i) a synthetic strategy that affords modular synthesis of radiolabeling precursors via a copper-catalyzed ‘click’ reaction; and (ii) a one-step 18F-labeling method that obviates the need for HPLC purification. Within 30 min, 18F-labeled PET imaging probes, such as peptides, can be synthesized in good chemical and radiochemical purity (>98%), satisfactory radiochemical yield of 20–35% (n > 20, non-decay corrected) and high specific activity of 40–111 GBq/µmol (1.1–3.0 Ci/µmol). The entire procedure, including the precursor preparation and 18F radiolabeling, takes 7–10 d. PMID:26313478

  14. F 3 - molecular ions in fluoride crystals

    NASA Astrophysics Data System (ADS)

    Radzhabov, E. A.

    2016-02-01

    The UV absorption spectra of F 3 - molecular ions in LaF3, SrF2, CaF2, and BaF2 crystals doped with rare-earth elements are studied. Comparison of radiation-colored and additively colored crystals reveals the absorption bands of F 3 - hole centers in the region near 6 eV. Nonempirical calculations of optical transitions agree well with experimental results.

  15. Mn-salen catalysed benzylic C-H activation for the synthesis of aryl [(18)F]CF3-containing PET probes.

    PubMed

    Carroll, L; Evans, H L; Spivey, A C; Aboagye, E O

    2015-05-18

    The development of a Mn-salen complex catalysed oxidative benzylic fluorination of non-activated C-H bonds using [(18)F]fluoride is described for installation of [(18)F]CHRF, [(18)F]CR2F and particularly [(18)F]CF3 containing groups in the presence of other functional groups.

  16. Removal of fluoride ions from drinking water and fluoride solutions by aluminum modified iron oxides in a column system.

    PubMed

    García-Sánchez, J J; Solache-Ríos, M; Martínez-Miranda, V; Solís Morelos, C

    2013-10-01

    The purpose of this work was to evaluate the potential of aluminum modified iron oxides, in a continuous flow for removal of fluoride ions from aqueous solutions and drinking water. The breakthrough curves obtained for fluoride ions adsorption from aqueous solutions and drinking water were fitted to Thomas, Bohart-Adams, and bed depth service time model (BDST). Adsorption capacities at the breakthroughs, Thomas model constant, kinetic constant and the saturation concentration were determined. The results show that in general, the adsorption efficiency decreases as the bed depth increases, and this behavior shows that the adsorption is controlled by the mass transport resistance. The adsorption capacity for fluoride ions by CP-Al is higher for fluoride aqueous solutions than drinking water. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Synthesis of 2'-deoxy-2'-[18F]fluoro-beta-D-arabinofuranosyl nucleosides, [18F]FAU, [18F]FMAU, [18F]FBAU and [18F]FIAU, as potential PET agents for imaging cellular proliferation. Synthesis of [18F]labelled FAU, FMAU, FBAU, FIAU.

    PubMed

    Mangner, Thomas J; Klecker, Raymond W; Anderson, Lawrence; Shields, Anthony F

    2003-04-01

    An efficient and reliable synthesis of 2'-deoxy-2'-[(18)F]fluoro-beta-D-arabinofuranosyl nucleosides is presented. Overall decay-corrected radiochemical yields of 35-45% of 4 analogs, FAU, FMAU, FBAU and FIAU are routinely obtained in >98% radiochemical purity and with specific activities of greater than 3 Ci/micromol (110 MBq/micromol) in a synthesis time of approximately 3 hours. When approximately 220 mCi (8.15 GBq) of starting [(18)F]fluoride is used, 25 -30 mCi (0.93 -1.11 GBq) of product (enough to image two patients sequentially) is typically obtained.

  18. .sup.18 F-4-Fluoroantipyrine

    DOEpatents

    Shiue, Chyng-Yann; Wolf, Alfred P.

    1984-03-13

    The novel radioactive compound .sup.18 F-4-fluoroantipyrine having high specific activity which can be used in nuclear medicine in diagnostic applications, prepared by the direct fluorination of antipyrine in acetic acid with radioactive fluorine at room temperature and purifying said radioactive compound by means of gel chromatography with ethyl acetate as eluent is disclosed. The non-radioactive 4-fluoroantipyrine can also be prepared by the direct fluorination of antipyrine in acetic acid with molecular fluorine at room temperature and purified by means of gel chromotography with ethyl acetate eluent.

  19. Highly efficient production of [(18)F]fallypride using small amounts of base concentration.

    PubMed

    Moon, Byung Seok; Park, Jun Hyung; Lee, Hong Jin; Kim, Ji Sun; Kil, Hee Sup; Lee, Byoung Se; Chi, Dae Yoon; Lee, Byung Chul; Kim, Yu Kyeong; Kim, Sang Eun

    2010-12-01

    To minimize the base concentration of a phase-transfer catalyst, [(18)F]fluoride was extracted from (18)O-enriched water trapped on an activated ion exchange cartridge (Chromafix PS-HCO(3)) using different concentrations of tetrabutylammonium bicarbonate (TBAHCO(3)) or Kryptofix 2.2.2./K(2)CO(3) in organic solvents such as CH(3)CN/H(2)O or MeOH/H(2)O. The optimal labeling condition for [(18)F]fallypride with automated synthesis was that 2 mg of tosyl-fallypride in acetonitrile (1 mL) was heated at 100 degrees C for 10 min using 40% TBAHCO(3) (10 microL). [(18)F]Fallypride was obtained with a high radiochemical yield of approximately 68+/-1.6% (decay-corrected, n=42) with a total synthesis time of 51+/-1.2 min, including HPLC purification and solid-phase purification for the final formulation. Copyright 2010 Elsevier Ltd. All rights reserved.

  20. Low molecular weight fluorescent organogel for fluoride ion detection.

    PubMed

    Rajamalli, P; Prasad, Edamana

    2011-07-15

    The design, synthesis, and the photophysical properties of a Low Molecular Weight Gel (LMWG) based on AB(3) and AB(2) type poly(aryl ether) dendrons with an anthracene chromophore attached through an acylhydrazone linkage are described. The gel is utilized for an efficient 'naked eye' detection of fluoride ions (as low as 0.1 equiv with respect to the gelator concentration), through a reversible gel-sol transition, which is associated with a color change from deep yellow to bright red. © 2011 American Chemical Society

  1. Removal of fluoride ions from water by adsorption onto carbonaceous materials produced from coffee grounds.

    PubMed

    Ogata, Fumihiko; Tominaga, Hisato; Yabutani, Hitoshi; Kawasaki, Naohito

    2011-01-01

    Carbonaceous material for the removal of fluoride ions from water was prepared from coffee grounds (CGs) by calcination and subsequent HCl treatment. The characteristics of the CGs, including the surface area, mean pore diameter, pore volume, and surface functional groups were determined, and the morphological characteristics were evaluated using scanning electron microscopy. The adsorption isotherms, saturated amount of fluoride ions adsorbed, and the effect of contact time and temperature on the adsorption of fluoride ions were investigated for a sample of tap water. The specific surface area of CG calcined at 600° (CG600) was larger than that of CGs calcined at 400, 800, and 1000°. Phenolic, lactonic, and carboxyl groups were detected on the CG600 surface. The adsorption capacity of the carbonized CGs for fluoride was ranked in the order CG400 < CG1000 < CG800 < CG600 (where the numeral indicates the carbonization temperature), whereas virgin CG and CG600-NAT (not treated with hydrochloric acid solution) did not exhibit any adsorption ability for fluoride ions. The amount of fluoride ions adsorbed onto CG600 increased with increasing temperature and was consistent with chemical adsorption. The mechanism of adsorption of fluoride ions onto CG600 proceeded via ion exchange with chloride ions (1:1) present on the surface of CG600. The adsorption isotherms were fitted to the Freundlich and Langmuir equations. Moreover, CG600 showed an acceptable adsorption capacity for fluoride ions present in tap water.

  2. Uniform partial dissolution of bone mineral by using fluoride and phosphate ions combination.

    PubMed

    DePaula, Carl Alex; Pan, Yong; Guzelsu, Nejat

    2008-01-01

    Mineral content is one of the main predictors of the mechanical properties of bone tissue. The contribution of the bone mineral phase to the mechanical properties of bone has been investigated by reducing the mineral content of bone with different in vitro treatment techniques such as hydrochloric acid (HCl), ethylenedinitrilo tetraacetic acid (EDTA), and fluoride ion treatment. In this study, we propose a new treatment technique which combines fluoride and phosphate ions. Bovine femur specimens were used to determine the mechanical properties of cortical bone after different fluoride phosphate ion combination treatments. The treatment solutions, which contain different fluoride and phosphate ion concentrations, dissolved part of the bone mineral in a uniform manner throughout the bone samples. Dissolution by products, which precipitated in the bone tissue, contained calcium fluoride with phosphate ions (CaF(2)/P) and fluorapatite/fluorhydroxyapatite-type material (FAp/FHAp) and acted as filler. Depending on the fluoride and phosphate concentration in a treatment solution, the precipitated material's ratio of FAp/FHAp to total fluoride containing phase (FAp/FHAp + CaF(2)/P) in bone tissue also changed. High fluoride ion content in treatment solutions generated more CaF(2)/P type of precipitate, and low fluoride ion concentration generated more FAp/FHAp type precipitates as compared to high fluoride concentration treatments. These experiments show that phosphate ions are another important parameter of a treatment solution, in addition to ionic strength, pH, and the duration of treatment. In vitro, phosphate fluoride combinations partially dissolve bone mineral content in a wider range than fluoride treatment alone in a uniform manner. With this new technique one can control more precisely the partial dissolution of the bone mineral and mineral phase's contribution to mechanical properties of bone tissue.

  3. High yield synthesis of 6-(18F)fluoro-L-dopa

    SciTech Connect

    Chirakal, R.; Firnau, G.; Garnett, E.S.

    1986-03-01

    The radiofluorination of L-dopa with (/sup 18/F)F2 was investigated with the purpose of improving the yield of 6-(/sup 18/F)fluoro-L-dopa. When boron trifluoride was added to the reaction mixture in hydrogen fluoride (HF), the yield was increased threefold. Nine millicuries of 6-(/sup 18/F)fluoro-L-dopa were produced from 100 mCi (/sup 18/F)F2 routinely and reliably after 2 hr of preparation. If acetonitrile or water were substituted for HF, little or no 6-fluoro-L-dopa was made.

  4. An automated synthesizer for electrochemical (18)F-fluorination of organic compounds.

    PubMed

    Waldmann, Christopher M; Lebedev, Artem; Allison, Nathaniel; Sadeghi, Saman

    2017-09-01

    Electrochemical (18)F-fluorination of organic compounds provides a means to synthesize Positron-Emission-Tomography (PET) tracers difficult to obtain otherwise. Here, the first automated synthesizer that enables radiolabeling through carrier-added electrochemical (18)F-fluorination is described. The system provides capabilities for all necessary operations such as drying of cyclotron derived [(18)F]fluoride, electrochemical incorporation of the radioisotope into a precursor molecule, subsequent reactions such as protecting group removals, HPLC-purification and formulation of the final tracer. Demonstrated is the aliphatic electrochemical (18)F-fluorination of methyl 2-(phenylthio)acetate. Copyright © 2017. Published by Elsevier Ltd.

  5. An automated synthesizer for electrochemical 18F-fluorination of organic compounds

    PubMed Central

    Waldmann, Christopher M.; Lebedev, Artem; Allison, Nathaniel; Sadeghi, Saman

    2017-01-01

    Electrochemical 18F-fluorination of organic compounds provides a means to synthesize Positron-Emission-Tomography (PET) tracers difficult to obtain otherwise. Here, the first automated synthesizer that enables radiolabeling through carrier-added electrochemical 18F-fluorination is described. The system provides capabilities for all necessary operations such as drying of cyclotron derived [18F]fluoride, electrochemical incorporation of the radioisotope into a precursor molecule, subsequent reactions such as protecting group removals, HPLC-purification and formulation of the final tracer. Demonstrated is the aliphatic electrochemical 18F-fluorination of methyl 2-(phenylthio)acetate. PMID:28662441

  6. 21-(/sup 18/F)fluoro-16 alpha-ethyl-19-norprogesterone: synthesis and target tissue selective uptake of a progestin receptor based radiotracer for positron emission tomography

    SciTech Connect

    Pomper, M.G.; Katzenellenbogen, J.A.; Welch, M.J.; Brodack, J.W.; Mathias, C.J.

    1988-07-01

    We have synthesized 21-(/sup 18/F)fluoro-16 alpha-ethyl-19-norprogesterone (FENP), a high affinity ligand for the progesterone receptor, labeled with the positron-emitting radionuclide fluorine-18 (t1/2 = 110 min). The synthesis proceeds in two steps from 21-hydroxy-16 alpha-ethyl-19-norprogesterone and involves (/sup 18/F)fluoride ion displacement of the 21-trifluoromethanesulfonate (21-triflate). This material is purified by HPLC and is obtained in 4-30% overall yield (decay corrected) within 40 min after the end of bombardment to produce (/sup 18/F)fluoride ion. The effective specific activity, determined by competitive radioreceptor binding assays, is 700-1400 Ci/mmol. In vivo, (/sup 18/F)FENP demonstrates highly selective, receptor-mediated uptake by the uterus of estrogen-primed rats; the uterus to blood and uterus to muscle ratios were respectively 26 and 16 at 1 h and 71 and 41 at 3 h after injection. The high target tissue selectivity of this uptake suggests that this compound may be useful for the in vivo imaging of progestin target tissues and receptor-rich tumors (such as human breast tumors) by positron emission tomography.

  7. Dual mode fluorescent (18)F-PET tracers: efficient modular synthesis of rhodamine-[cRGD]2-[(18)F]-organotrifluoroborate, rapid, and high yielding one-step (18)F-labeling at high specific activity, and correlated in vivo PET imaging and ex vivo fluorescence.

    PubMed

    Liu, Zhibo; Radtke, Mark Alex; Wong, May Q; Lin, Kuo-Shyan; Yapp, Donald T; Perrin, David M

    2014-11-19

    The design of dual mode fluorescent-PET peptidic tracers that can be labeled with [(18)F]fluoride at high specific activity and high yield has been challenged by the short half-life of (18)F and its aqueous indolence toward nucleophilic displacement, that often necessitates multistep reactions that start with punctiliously dry conditions. Here we present a modular approach to constructing a fluorescent dimeric peptide with a pendant radioprosthesis that is labeled in water with [(18)F]fluoride ion in a single, user-friendly step. The modular approach starts with grafting a new zwitterionic organotrifluoroborate radioprosthesis onto a pentaerythritol core with three pendent alkynes that enable successive grafting of a bright fluorophore (rhodamine) followed by two peptides (cylcoRGD). The construct is labeled with [(18)F]fluoride via isotope exchange within 20 min in a single step at high specific activity (>3 Ci/μmol) and in good yield to provide 275 mCi and high radiochemical purity. Neither drying of the [(18)F]fluoride ion solution nor HPLC purification of the labeled tracer is required. Facile chemical synthesis of this dual mode tracer along with a user-friendly one-step radiolabeling method affords very high specific activity. In vivo PET images of the dual mode tracer are acquired at both high and low specific activities. At very high specific activity, i.e., 3.5 Ci/μmol, tumor uptake is relatively high (5.5%ID/g), yet the associated mass is below the limits of fluorescent detection. At low specific activity, i.e., 0.01 Ci/μmol, tumor uptake in the PET image is reduced by approximately 50% (2.9%ID/g), but the greater associated mass enables fluorescence detection in the tumor. These data highlight a facile production of a dual mode fluorescent-PET tracer which is validated with in vivo and ex vivo images. These data also define critical limitations for the use of dual mode tracers in small animals.

  8. A turn-on fluorescence probe for the selective and sensitive detection of fluoride ions.

    PubMed

    Zhang, Shan; Sun, Mingtai; Yan, Yehan; Yu, Huan; Yu, Tao; Jiang, Hui; Zhang, Kui; Wang, Suhua

    2017-03-01

    The sensitive and selective determination of fluoride ions is particularly significant in environmental protection, food safety, and health care products. In this work, a highly selective turn-on fluorescent probe for fluoride ions has been synthesized by simply functionalizing fluorescent isophthalaldehyde with silicone-oxygen bonding. The selectivity of the probe is based on the specific reactivity of the silyl group toward fluoride ions in aqueous solution. The nucleophilic substitution reaction of fluoride ions triggers the cleavage of the Si-O bond to release a strongly fluorescent product, which can be used for the determination of fluoride ions by fluorescence intensity enhancement. The probe molecules are specifically responsive and highly selective for the fluoride anion over other relevant anions and cations. This fluorescent probe also shows high photostability and exhibits good sensitivity for fluoride ions, and the limit of detection is as low as 67 ppb. We have demonstrated its application for on-site sensitive determination of fluoride ions for environmental monitoring and protection.

  9. 18F-AFETP, 18F-FET, and 18F-FDG Imaging of Mouse DBT Gliomas

    PubMed Central

    Sai, Kiran Kumar Solingapuram; Huang, Chaofeng; Yuan, Liya; Zhou, Dong; Piwnica-Worms, David; Garbow, Joel R.; Engelbach, John A.; Mach, Robert H.; Rich, Keith M.; McConathy, Jonathan

    2013-01-01

    The goal of this study was to evaluate the 18F-labeled nonnatural amino acid (S)-2-amino-3-[1-(2-18F-fluoroethyl)-1H-[1,2,3]triazol-4-yl]propanoic acid (18F-AFETP) as a PET imaging agent for brain tumors and to compare its effectiveness with the more-established tracers O-(2-18F-fluoroethyl)-L-tyrosine (18F-FET) and 18F-FDG in a murine model of glioblastoma. The tracer 18F-AFETP is a structural analog of histidine and is a lead compound for imaging cationic amino acid transport, a relatively unexplored target for oncologic imaging. Methods 18F-AFETP was prepared using the click reaction. BALB/c mice with intracranially implanted delayed brain tumor (DBT) gliomas (n = 4) underwent biodistribution and dynamic small-animal PET imaging for 60 min after intravenous injection of 18F-AFETP. Tumor and brain uptake of 18F-AFETP were compared with those of 18F-FDG and 18F-FET through small-animal PET analyses. Results 18F-AFETP demonstrated focally increased uptake in tumors with good visualization. Peak tumor uptake occurred within 10 min of injection, with stable or gradual decrease over time. All 3 tracers demonstrated relatively high uptake in the DBTs throughout the study. At late time points (47.5–57.5 min after injection), the average standardized uptake value with 18F-FDG (1.9 ± 0.1) was significantly greater than with 18F-FET (1.1 ± 0.1) and 18F-AFETP (0.7 ± 0.2). The uptake also differed substantially in normal brain, with significant differences in the standardized uptake values at late times among 18F-FDG (1.5 ± 0.2), 18F-FET (0.5 ± 0.05), and 18F-AFETP (0.1 ± 0.04). The resulting average tumor-to-brain ratio at the late time points was significantly higher for 18F-AFETP (7.5 ± 0.1) than for 18F-FDG (1.3 ± 0.1) and 18F-FET (2.0 ± 0.3). Conclusion 18F-AFETP is a promising brain tumor imaging agent, providing rapid and persistent tumor visualization, with good tumor–to–normal-brain ratios in the DBT glioma model. High tumor-to-brain, tumor

  10. A Fully-automated One-pot Synthesis of [18F]Fluoromethylcholine with Reduced Dimethylaminoethanol Contamination via [18F]Fluoromethyl Tosylate

    PubMed Central

    Rodnick, Melissa E.; Brooks, Allen F.; Hockley, Brian G.; Henderson, Bradford D.; Scott, Peter J. H.

    2013-01-01

    Introduction A novel one-pot method for preparing [18F]fluoromethylcholine ([18F]FCH) via in situ generation of [18F]fluoromethyl tosylate ([18F]FCH2OTs), and subsequent [18F]fluoromethylation of dimethylaminoethanol (DMAE), has been developed. Methods [18F]FCH was prepared using a GE TRACERlab FXFN, although the method should be readily adaptable to any other fluorine-18 synthesis module. Initially ditosylmethane was fluorinated to generate [18F]FCH2OTs. DMAE was then added and the reaction was heated at 120°C for 10 min to generate [18F]FCH. After this time, reaction solvent was evaporated, and the crude reaction mixture was purified by solid-phase extraction using C18-Plus and CM-Light Sep-Pak cartridges to provide [18F]FCH formulated in USP saline. The formulated product was passed through a 0.22 μm filter into a sterile dose vial, and submitted for quality control testing. Total synthesis time was 1.25 hours from end-of-bombardment. Results Typical non-decay-corrected yields of [18F]FCH prepared using this method were 91 mCi (7% non-decay corrected based upon ~1.3 Ci [18F]fluoride), and doses passed all other quality control (QC) tests. Conclusion A one-pot liquid-phase synthesis of [18F]FCH has been developed. Doses contain extremely low levels of residual DMAE (31.6 μg / 10 mL dose or ~3 ppm) and passed all other requisite QC testing, confirming their suitability for use in clinical imaging studies. PMID:23665261

  11. Automated cGMP-compliant radiosynthesis of [(18) F]-(E)-PSS232 for brain PET imaging of metabotropic glutamate receptor subtype 5.

    PubMed

    Park, Jun Young; Son, Jeongmin; Yun, Mijin; Ametamey, Simon M; Chun, Joong-Hyun

    2017-09-25

    (E)-3-(Pyridin-2-yl ethynyl)cyclohex-2-enone O-(3-(2-[(18) F]-fluoroethoxy)propyl) oxime ([(18) F]-(E)-PSS232, [(18) F]2a) is a recently developed radiotracer that can be used to visualize metabotropic glutamate receptor subtype 5 (mGlu5 ) in vivo. The mGlu5 has become an attractive therapeutic and diagnostic target owing to its role in many neuropsychiatric disorders. Several carbon-11- and fluorine-18-labelled radiotracers have been developed to measure mGlu5 receptor occupancy in the human brain. The radiotracer [(18) F]2a, which is used as an analogue for [(11) C]ABP688 ([(11) C]1) and has a longer physical half-life, is a selective radiotracer that exhibits high binding affinity for mGlu5 . Herein, we report the fully automated radiosynthesis of [(18) F]2a using a commercial GE TRACERlab(TM) FX-FN synthesizer for routine production and distribution to nearby satellite clinics. Nucleophilic substitution of the corresponding mesylate precursor with cyclotron-produced [(18) F]fluoride ion at 100 °C in dimethyl sulfoxide (DMSO), followed by high-performance liquid chromatography (HPLC) purification and formulation, readily provided [(18) F]2a with a radiochemical yield of 40 ± 2% (decay corrected, n = 5) at the end of synthesis. Radiochemical purity for the [(18) F]-(E)-conformer was greater than 95%. Molar activity was determined to be 63.6 ± 9.6 GBq/μmol (n = 5), and the overall synthesis time was 70 min. This article is protected by copyright. All rights reserved.

  12. Novel azo dye-based color chemosensors for fluoride ions.

    PubMed

    Cho, Eun Jin; Lee, Yongjun; Bae, Hyeun-Jong; Lee, Young Ju

    2015-01-01

    Two novel fluoride (F(-)) sensors based on an azo dye (solvent yellow 4) were designed and synthesized. The chemosensors exhibited selectivity and high sensitivity towards F(-) over other anions such as Cl(-), Br(-), I(-), CH3COO(-), C6H5COO(-), and H2PO4(-), as noted by the naked eye and UV-vis spectral changes in DMSO/CH3CN (1:9, v/v). An obvious change in the color of the sensor solution from pale yellow to pink occurred after the addition of F(-), while the addition of other anions did not cause any change in color. These results imply that the two sensors are viable, portable chemosensors for the detection of F(-) ions in various biological and environmental fields. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Removing Fluoride Ions with Continously Fed Activated Alumina.

    ERIC Educational Resources Information Center

    Wu, Yeun C.; Itemaking, Isara Cholapranee

    1979-01-01

    Discussed is the mathematical basis for determining fluoride removal during water treatment with activated alumina. The study indicates that decreasing particle size decreases the pore diffusion effect and increases fluoride removal. (AS)

  14. Removing Fluoride Ions with Continously Fed Activated Alumina.

    ERIC Educational Resources Information Center

    Wu, Yeun C.; Itemaking, Isara Cholapranee

    1979-01-01

    Discussed is the mathematical basis for determining fluoride removal during water treatment with activated alumina. The study indicates that decreasing particle size decreases the pore diffusion effect and increases fluoride removal. (AS)

  15. The improved syntheses of 5-substituted 2'-[18F]fluoro-2'-deoxy-arabinofuranosyluracil derivatives ([18F]FAU, [18F]FEAU, [18F]FFAU, [18F]FCAU, [18F]FBAU and [18F]FIAU) using a multistep one-pot strategy.

    PubMed

    Cai, Hancheng; Li, Zibo; Conti, Peter S

    2011-07-01

    We and others have previously reported a four-step radiosynthesis of a series of 2'-deoxy-2'-[(18)F]fluoro-5-substituted-1-β-D-arabinofuranosyluracil derivatives including [(18)F]FAU, [(18)F]FEAU, [(18)F]FFAU, [(18)F]FCAU, [(18)F]FBAU and [(18)F]FIAU as thymidine derivatives for tumor proliferation and/or reporter gene expression imaging with positron emission tomography (PET). Although the radiosynthesis has been proven to be reproducible and efficient, this complicated multistep reaction is difficult to incorporate into an automated cGMP-compliant radiosynthesis module for routine production. Recently, we have developed a simple and efficient one-pot method for routine production of [(18)F]FMAU. In this study, we studied the feasibility of radiosynthesizing [(18)F]FAU, [(18)F]FEAU, [(18)F]FFAU, [(18)F]FCAU, [(18)F]FBAU and [(18)F]FIAU using this newly developed method. Similar to the radiosynthesis of [(18)F]FMAU, 5-substituted 2'-[(18)F]fluoro-2'-deoxy-arabinofuranosyluracil derivatives ([(18)F]FAU, [(18)F]FEAU, [(18)F]FFAU, [(18)F]FCAU, [(18)F]FBAU and [(18)F]FIAU) were synthesized in one-pot radiosynthesis module in the presence of Friedel-Crafts catalyst TMSOTf and HMDS. This one-pot radiosynthesis method could be used to produce [(18)F]FAU, [(18)F]FEAU, [(18)F]FFAU, [(18)F]FCAU, [(18)F]FBAU and [(18)F]FIAU. The overall radiochemical yields of these tracers varied from 4.1%±0.8% to 10.1%±1.9% (decay-corrected, n=4). The overall reaction time was reduced from 210 min to 150 min from the end of bombardment, and the radiochemical purity was >99%. The improved radiosyntheses of [(18)F]FAU, [(18)F]FEAU, [(18)F]FFAU, [(18)F]FCAU, [(18)F]FBAU and [(18)F]FIAU have been achieved with reasonable yields and high purity using a multistep one-pot method. The synthetic time has been reduced, and the reaction procedures have been significantly simplified. The success of this approach may make PET tracers [(18)F]FAU, [(18)F]FEAU, [(18)F]FFAU, [(18)F]FCAU, [(18)F]FBAU and

  16. Corrosion studies of various heavy-metal fluoride glasses in liquid water: Application to fluoride-ion-selective electrode

    SciTech Connect

    Ravaine, D.; Perera, G.

    1986-12-01

    The leaching rates of various heavy-metal flouride (HMF) glasses have been investigated in pH-buffered solutions. Measurements of weight losses and fluoride-ion and heavy-metal concentrations in solution have been performed. The agreement between the different experimental methods suggests a congruent dissolution although different time dependencies are observed between the investigated glasses.

  17. Removal of fluoride ion from aqueous solution by a cerium-poly(hydroxamic acid) resin complex.

    PubMed

    Haron, M J; Yunus, W M

    2001-05-01

    A cerium-loaded poly(hydroxamic acid) chelating ion exchanger was used for fluoride ion removal from aqueous solution. The resin was effective in decreasing the fluoride concentration from 5 mM down to 0.001 mM in acidic pH between 3 and 6. The sorption followed a Langmuir model with a maximum capacity of 0.5 mmol/g. The removal is accomplished by an anion exchange mechanism. The rate constant for the sorption was found to be 9.6 x 10(-2) min-1. A column test shows that the fluoride ion was retained on the column until breakthrough point and the fluoride sorbed in the column can be eluted with 0.1 M NaOH. The column can be reused after being condition with hydrochloric acid at pH 4. The resin was tested and found to be effective for removal of fluoride from actual industrial wastewater.

  18. Efficient Automated Syntheses of High Specific Activity 6-[18F]Fluorodopamine Using A Diaryliodonium Salt Precursor

    PubMed Central

    Neumann, Kiel D.; Qin, Linlin; Vāvere, Amy L.; Shen, Bin; Miao, Zheng; Chin, Frederick T.; Shulkin, Barry L.; Snyder, Scott E.; DiMagno, Stephen G.

    2015-01-01

    6-[18F]Fluorodopamine, 6-[18F]F-DA, is a PET radiopharmaceutical used to image sympathetic cardiac innervation and neuroendocrine tumors. Imaging with 6-[18F]F-DA is constrained, in part, by the bioactivity and neurotoxicity of 6-[19F]fluorodopamine. Furthermore, routine access to this radiotracer is limited by the inherent difficulty of incorporation of [18F]fluoride into electron-rich aromatic substrates. We describe the simple and direct preparation of high specific activity (SA) 6-[18F]F-DA from no-carrier-added (n.c.a.) [18F]fluoride. Incorporation of n.c.a. [18F]fluoride into a diaryliodonium salt precursor was achieved in 50–75% radiochemical yields (decay-corrected to EOB). Synthesis of 6-[18F]F-DA on the IBA Synthera® and GE TRACERlab FX-FN automated platforms gave 6-[18F]F-DA in >99% chemical and radiochemical purities after HPLC purification. The final non-corrected yields of 6-[18F]F-DA were 25 ± 4% (n = 4, 65 min) and 31 ± 6% (n = 3, 75 min) using the Synthera and TRACERlab modules, respectively. Efficient access to high SA 6-[18F]F-DA from a diaryliodonium salt precursor and n.c.a. [18F]fluoride is provided by a relatively subtle change in reaction conditions; replacement of a polar aprotic solvent (acetonitrile) with a relatively nonpolar solvent (toluene) during the critical radiofluorination reaction. Implementation of this process on common radiochemistry platforms should make 6-[18F]fluorodopamine readily available to the wider imaging community. PMID:26695865

  19. Analytical Determination of Fluoride Ion Using Gran's Semi-Antilog Plot.

    ERIC Educational Resources Information Center

    Barnhard, Ralph J.

    1983-01-01

    A quantitative determination for fluoride ion using a commercially available fluoride electrode is described. The procedure referred to as known-addition is employed with the data processed on Gran's Plot Paper. Background information, experimental procedures, and advantages/disadvantages of the method are discussed. (JN)

  20. Analytical Determination of Fluoride Ion Using Gran's Semi-Antilog Plot.

    ERIC Educational Resources Information Center

    Barnhard, Ralph J.

    1983-01-01

    A quantitative determination for fluoride ion using a commercially available fluoride electrode is described. The procedure referred to as known-addition is employed with the data processed on Gran's Plot Paper. Background information, experimental procedures, and advantages/disadvantages of the method are discussed. (JN)

  1. New Dioxaborolane Chemistry Enables [(18)F]-Positron-Emitting, Fluorescent [(18)F]-Multimodality Biomolecule Generation from the Solid Phase.

    PubMed

    Rodriguez, Erik A; Wang, Ye; Crisp, Jessica L; Vera, David R; Tsien, Roger Y; Ting, Richard

    2016-05-18

    New protecting group chemistry is used to greatly simplify imaging probe production. Temperature and organic solvent-sensitive biomolecules are covalently attached to a biotin-bearing dioxaborolane, which facilitates antibody immobilization on a streptavidin-agarose solid-phase support. Treatment with aqueous fluoride triggers fluoride-labeled antibody release from the solid phase, separated from unlabeled antibody, and creates [(18)F]-trifluoroborate-antibody for positron emission tomography and near-infrared fluorescent (PET/NIRF) multimodality imaging. This dioxaborolane-fluoride reaction is bioorthogonal, does not inhibit antigen binding, and increases [(18)F]-specific activity relative to solution-based radiosyntheses. Two applications are investigated: an anti-epithelial cell adhesion molecule (EpCAM) monoclonal antibody (mAb) that labels prostate tumors and Cetuximab, an anti-epidermal growth factor receptor (EGFR) mAb (FDA approved) that labels lung adenocarcinoma tumors. Colocalized, tumor-specific NIRF and PET imaging confirm utility of the new technology. The described chemistry should allow labeling of many commercial systems, diabodies, nanoparticles, and small molecules for dual modality imaging of many diseases.

  2. Crystal structures of a double-barrelled fluoride ion channel

    PubMed Central

    Stockbridge, Randy B.; Kolmakova-Partensky, Ludmila; Shane, Tania; Koide, Akiko; Koide, Shohei; Miller, Christopher; Newstead, Simon

    2016-01-01

    To contend with hazards posed by environmental fluoride, microorganisms export this anion through F--specific ion channels of the Fluc family1–4. Since the recent discovery of Fluc channels, numerous idiosyncratic features of these proteins have been unearthed, including extreme selectivity for F- over Cl- and dual-topology dimeric assembly5–6. To understand the chemical basis for F- permeation and how the antiparallel subunits convene to form a F--selective pore, we solved crystal structures of two bacterial Fluc homologues in complex with three different monobody inhibitors, with and without F- present, to a maximum resolution of 2.1 Å. The structures reveal a surprising “double-barrelled” channel architecture in which two F- ion pathways span the membrane and the dual-topology arrangement includes a centrally coordinated cation, most likely Na+. F- selectivity is proposed to arise from the very narrow pores and an unusual anion coordination that exploits the quadrupolar edges of conserved phenylalanine rings. PMID:26344196

  3. Effect of fluoride-ion implantation on the biocompatibility of titanium for dental applications

    NASA Astrophysics Data System (ADS)

    Liu, H. Y.; Wang, X. J.; Wang, L. P.; Lei, F. Y.; Wang, X. F.; Ai, H. J.

    2008-08-01

    This study stressed on the effect of fluoride-ion implantation upon the biocompatibility of titanium. By using plasma immersion ion implantation technique, fluoride ions were implanted into the smooth surface of pure titanium. The chemical composition and physical structure of the modified surface layers were characterized by X-ray photoelectron spectroscopy (XPS) as well as scanning electron microscope (SEM). At the same time, in vitro co-culture assays were performed to evaluate the biocompatibility of MG-63 cells to the modified titanium. It was confirmed by SEM observations that cell growth on the fluoride-ion-implanted titanium acquired better morphological characters. In addition, the cells on the fluoride-ion-implanted titanium showed the more increasingly and rapidly substrates-attaching capabilities than those on the non-implanted titanium via aridine orange stain assay. Fluoride-ion-implanted titanium could increase the percentages of cells in S phase but without affecting the ratios of cells in G 0/G 1 and G 2/M phases was confirmed by flow cytometry assay. The current results indicated that fluoride-ion implantation could improve the biocompatibility of titanium.

  4. Study of wear analysis with {sup 18}F

    SciTech Connect

    Schmidt, N.; Nolen, J.A.; Blumenthal, D.J.

    1995-08-01

    We are studying the possible use of low-energy radioactive beams for the wear analysis of various industrial components (e.g. engine parts and materials for orthopedic implants). Previous experiments with {sup 7}Be and {sup 22}Na studied components at implantation depths of several tens of micrometer. In a first series of experiments we implanted {sup 18}F ions into the surface layer, which opens the possibility to study wear in the critical first micrometer of various materials. {sup 18}F was produced via the p({sup 18}O, {sup 18}F)n reaction at E{sub 18}{sub O} = 110 MeV using a 1.22-mg/cm{sub 2} polypropylene foil as a hydrogen target. The {sup 18}F{sup 9+} ions were separated at {theta}=0{degrees} from the incident {sup 18}O{sup 8+} beam with the split-pole spectrograph. In order to allow for a rapid change of irradiation samples, the {sup 18}F ions penetrated a thin HAVAR foil and were implanted into the sample which was located outside the vacuum chamber behind the pressure window. The depth distribution of the {sup 18}F was tested by implantation into a series of 1.5-{mu} thick Mylar foils which were subsequently measured with respect to their {sup 18}F activity using a Si-surface barrier detector. The localization of the {sup 18}F ions was found to be better than 1.5 {mu}. The implantation depth could be varied in the range between 1.5 {mu} - 9 {mu} by choosing the appropriate distance between pressure window and implantation sample. The wear rate was determined by measuring the (decay-corrected) decrease of the activity remaining in the sample after it was polished with Emery paper. In a first experiment the wear of stainless steel could be measured by this technique with a sensitivity of better than 100 nm. A paper describing these results is under preparation.

  5. Electrochemical reactions in fluoride-ion batteries: mechanistic insights from pair distribution function analysis

    DOE PAGES

    Grenier, Antonin; Porras-Gutierrez, Ana-Gabriela; Groult, Henri; ...

    2017-07-05

    Detailed analysis of electrochemical reactions occurring in rechargeable Fluoride-Ion Batteries (FIBs) is provided by means of synchrotron X-ray diffraction (XRD) and Pair Distribution Function (PDF) analysis.

  6. Efficient radiosynthesis of 3′-deoxy-3′-[18F]fluorothymidine using electrowetting-on-dielectric digital microfluidic chip

    PubMed Central

    Javed, Muhammad Rashed; Chen, Supin; Kim, Hee-Kwon; Wei, Liu; Czernin, Johannes; Kim, Chang-Jin “CJ”; van Dam, R. Michael; Keng, Pei Yuin

    2015-01-01

    Access to diverse PET tracers for preclinical and clinical research remains a major obstacle to research in cancer and other diseases research. The prohibitive cost and limited availability of tracers could be alleviated by microfluidic radiosynthesis technologies combined with high-yield microscale radiosynthetic method. In this report, we demonstrate the multistep synthesis of 3′-deoxy-3′-[18F]fluorothymidine ([18F]FLT) with high yield on an electrowetting on dielectric (EWOD) microfluidic radiosynthesizer, previously developed in our group. We have identified and established several parameters that are most critical in the microscale radiosynthesis such as the reaction time, reagent concentration, and molar ratios, to successfully synthesize [18F]FLT in this compact platform. Methods [18F]FLT was synthesized from the 3-N-Boc-1-[5-O-(4,4′-dimethoxytrityl)-3-O-nosyl-2-deoxy-β-d-lyxofuranosyl] thymine precursor on the EWOD chip starting from the first solvent exchange and [18F]fluoride ion activation step to the final deprotection step. The fluorination reaction was performed in a mixture of thexyl alcohol and DMSO. The crude product after deprotection was collected from the chip and purified on a custom-made solid phase extraction (SPE) cartridge and subjected to quality control testing. The purified [18F]FLT was suitable for microPET studies in multiple nude mice xenografted with the A431 carcinoma cell line. Results [18F]FLT was successfully synthesized on the EWOD microdevice coupled with an off-chip SPE purification with a decayed-corrected radiochemical yield of 63±5% (n=5) and passed all of the quality control test required by the United States Pharmacopeia for radiotracers to be injected into humans. We have successfully demonstrated the synthesis of several batches of [18F]FLT on EWOD starting with ∼ 333 MBq of radioactivity and obtained up to 52 MBq (non-decay corrected) of [18F]FLT upon cartridge purification. The specific activity of two

  7. Nucleophile Assisting Leaving Groups: A Strategy for Aliphatic 18F-Fluorination

    PubMed Central

    Lu, Shuiyu; Lepore, Salvatore D.; Li, Song Ye; Mondal, Deboprosad; Cohn, Pamela C.; Bhunia, Anjan K.; Pike, Victor W.

    2009-01-01

    A series of arylsulfonate nucleophile assisting leaving groups (NALGs) were prepared in which the metal chelating unit is attached to the aryl ring via an ether linker. These NALGs exhibited significant rate enhancements in halogenation reactions using metal halides. Studies with a NALG containing a macrocyclic ether unit suggest that rate enhancements of these nucleophilic halogenation reactions are facilitated by stabilization of charge in the transition state rather than through strong pre-complexation with metal cation. In several cases, a primary substrate containing one of the new leaving groups rivaled or surpassed the reactivity of triflates when exposed to nucleophile but was otherwise highly stable and isolable. These and previously disclosed chelating leaving groups were used in 18F-fluorination reactions using no-carrier-added [18F]fluoride ion (t1/2 = 109.7 min, β+ = 97%) in CH3CN. Under microwave irradiation and without the assistance of a cryptand, such as K2.2.2, primary substrates with select NALGs led to a substantial improvement (2 to 3 fold) in radiofluorination yields over traditional leaving groups. PMID:19572583

  8. A new buffer system for the potentiometric determination of fluoride ion

    SciTech Connect

    Zhobinskii, E.Y.; Askochenskaya, R.M.; Novikova, L.B; Wl' Figarov, O.S.

    1985-05-01

    This paper attempts to eliminate the lengthy stage of hydrolytic separation of the elements during the potentiometric determination of fluoride ions and also to develop a universal method for the determination of flouride ions. During the development of a procedure for the determination of fluoride ions it is necessary to eliminate the interfering effects of elements which form stable fluoride complexes such as A1 (III), Fe (III), Si (III), Ti (IV), V (IV), Mo (V), and W (V). By the addition of diethylenetriaminepentaacetate to the buffer solution and preliminary extraction of the benzoylphenylhydroxylaminates of the interfering elements with chloroform it was possible to develop a method for the determination of fluoride with a detection limit of 1.10/sup -5/ M.

  9. CHARACTERIZATION OF THE TANK 18F SAMPLES

    SciTech Connect

    Oji, L.; Click, D.; Diprete, D.

    2009-12-17

    The Savannah River National Laboratory (SRNL) was asked by Liquid Waste Operations to characterize Tank 18F closure samples. Tank 18F slurry samples analyzed included the liquid and solid fractions derived from the 'as-received' slurry materials along with the floor scrape bottom Tank 18F wet solids. These samples were taken from Tank 18F in March 2009 and made available to SRNL in the same month. Because of limited amounts of solids observed in Tank 18F samples, the samples from the north quadrants of the tank were combined into one North Tank 18F Hemisphere sample and similarly the south quadrant samples were combined into one South Tank 18F Hemisphere sample. These samples were delivered to the SRNL shielded cell. The Tank 18F samples were analyzed for radiological, chemical and elemental components. Where analytical methods yielded additional contaminants other than those requested by the customer, these results were also reported. The target detection limits for isotopes analyzed were 1E-04 {micro}Ci/g for most radionuclides and customer desired detection values of 1E-05 {micro}Ci/g for I-129, Pa-231, Np-237, and Ra-226. While many of the minimum detection limits, as specified in the technical task request and task technical and quality assurance plans were met for the species characterized for Tank 18F, some were not met due to spectral interferences. In a number of cases, the relatively high levels of radioactive species of the same element or a chemically similar element precluded the ability to measure some isotopes to low levels. SRNL, in conjunction with the plant customer, reviewed all these cases and determined that the impacts were negligible.

  10. Comparison of the biological effects of {sup 18}F at different intracellular levels

    SciTech Connect

    Kashino, Genro; Hayashi, Kazutaka; Douhara, Kazumasa; Kobashigawa, Shinko; Mori, Hiromu

    2014-11-07

    Highlights: • We estimated the inductions of DNA DSB in cell treated with {sup 18}F-FDG. • We found that inductions of DNA DSB are dependent on accumulation of {sup 18}F in cell. • Accumulation of {sup 18}F in cell may be indispensable for risk estimation of PET. - Abstract: We herein examined the biological effects of cells treated with {sup 18}F labeled drugs for positron emission tomography (PET). The relationship between the intracellular distribution of {sup 18}F and levels of damaged DNA has yet to be clarified in detail. We used culture cells (Chinese Hamster Ovary cells) treated with two types of {sup 18}F labeled drugs, fluorodeoxyglucose (FDG) and fluorine ion (HF). FDG efficiently accumulated in cells, whereas HF did not. To examine the induction of DNA double strand breaks (DSB), we measured the number of foci for 53BP1 that formed at the site of DNA DSB. The results revealed that although radioactivity levels were the same, the induction of 53BP1 foci was stronger in cells treated with {sup 18}F-FDG than in those treated with {sup 18}F-HF. The clonogenic survival of cells was significantly lower with {sup 18}F-FDG than with {sup 18}F-HF. We concluded that the efficient accumulation of {sup 18}F in cells led to stronger biological effects due to more severe cellular lethality via the induction of DNA DSB.

  11. Retention of fluoride ions from aqueous solution using porous hydroxyapatite. Structure and conduction properties.

    PubMed

    Hammari, L E L; Laghzizil, A; Barboux, P; Lahlil, K; Saoiabi, A

    2004-10-18

    Synthetic porous calcium hydroxyapatite (noted p-HAp) treated with different fluoride concentrations at room temperature in the presence of carbonate, sodium chloride and phosphate-rich media was investigated. The fluoridation rate of the porous calcium hydroxyapatite was 89% using 1 mol/L [F(-)] solution compared with 30% for crystalline hydroxyapatite (c-HAp). The high specific surface area of p-HAp (235 m(2)g(-1)) compared with c-HAp sample (47 m(2)g(-1)) has an important effect on the removal of fluoride ions from aqueous solution, when p-HAp was treated with high fluoride concentration to produce calcium fluorohydroxyapatite materials. Fluoride adsorption on porous hydroxyapatites (p-HAp) modified their structural and conduction properties.

  12. 18F: Labeling Chemistry and Labeled Compounds

    NASA Astrophysics Data System (ADS)

    Ross, T. L.; Wester, H. J.

    Positron emission tomography (PET) is a unique tool for the investigation, localization, and quantification of physiological activities in vivo by tracing the involved or accompanying biochemical processes. Because of its nuclear and chemical properties, fluorine-18, which is commonly produced by a cyclotron using the 18O(p,n)18F or the 20Ne(d,α)18F nuclear process, is a nearly ideal positron emitting radionuclide. Its half-life of 109.7 min permits tracer syntheses and imaging protocols extending over hours and allows distribution of 18F-radiopharmaceuticals to hospitals and facilities lacking a cyclotron. The low maximum positron energy of 635 keV results in low radiation doses, short ranges in tissue, and therefore in excellent imaging resolution. Introduction of 18F-fluorine, either via nucleophilic strategies using [18F]F- or electrophilic routes using molecular [18F]F2, permits the synthesis of a broad spectrum of compounds within a time compatible with the half-life. Although fluorine is only slightly larger than a hydrogen atom, changes in the physiological behavior of bioactive compounds as a result of alteration in metabolic stability, lipophilicity, affinity to the target, or other structures, etc., are often observed even after F-for-H or F-for-OH substitutions. In this chapter, an overview of the scope and limitations of the 18F-chemistry is given. Fluorination strategies, routes, and synthetic aspects are exemplified, as far as possible, by established and selected 18F-radiopharmaceuticals with clinical relevance or with potential for further clinical application.

  13. Fluoride removal by Al, Ti, and Fe hydroxides and coexisting ion effect.

    PubMed

    Zhang, Jianfeng; Brutus, Timothy E; Cheng, Jiemin; Meng, Xiaoguang

    2017-07-01

    Batch experiments were conducted to evaluate fluoride removal by Al, Fe, and Ti-based coagulants and adsorbents, as well as the effects of coexisting ions and formation of aluminum-fluoride complexes on fluoride removal by co-precipitation with alum (Al2(SO4)3·18H2O). Aluminum sulfate was more efficient than the other coagulants for fluoride removal in the pH range between 6 and 8. Nano-crystalline TiO2 was more effective for fluoride removal than Al and Fe hydroxides in a pH range of 3-5. Coexisting anions in water decreased the removal of fluoride in the order: phosphate (2.5mg/L)>arsenate (0.1mg/L)>bicarbonate (200mg/L)>sulfate (100mg/L)=nitrate (100mg/L)>silicate (10mg/L) at a pH of 6.0. The effect of silicate became more significant at pH>7.0. Calcium and magnesium improved the removal of fluoride. Zeta-potential measurements determined that the adsorption of fluoride shifted the PZC of Al(OH)3 precipitates from 8.9 to 8.4, indicating the chemical adsorption of fluoride at the surface. The presence of fluoride in solution significantly increased the soluble aluminum concentration at pH<6.5. A Visual MINTEQ modeling study indicated that the increased aluminum solubility was caused by the formation of AlF(2+), AlF2(+), and AlF3 complexes. The AlFx complexes decreased the removal of fluoride during co-precipitation with aluminum sulfate. Copyright © 2017. Published by Elsevier B.V.

  14. Ion chromatographic measurement of fluoride and sulfur dioxide in samples collected at aluminum smelters

    SciTech Connect

    Balya, D.R. )

    1991-08-01

    Measurement of airborne fluoride and sulfur dioxide in aluminum smelting plants is important for both industrial hygiene and environmental reasons. The traditional analytical techniques employed have been ion-selective electrodes (ISE) for fluoride and barium/thorin titration for SO2. In this study, ion chromatography (IC) was evaluated as a substitute for these two techniques. Dust for particulate fluoride was collected on membrane filters with carbonate-treated backup pads to collect HF and SO2. Gaseous fluoride and SO2 were ultrasonically extracted from the treated pad, but particulate fluoride required a borate/carbonate fusion. Collection efficiency and recovery of the analytes, along with the acceptable working ranges and instrument conditions used with IC, are discussed. IC is a desirable substitute for the electrode and titration methods because it is easily automated and the two determinations may be performed simultaneously. Organic compounds may cause interference in low-level fluoride measurement. Comparison of the techniques for field samples indicates that IC is an adequate substitute for the traditional measurement methods for full-shift samples of fluoride.

  15. 18F-Fluorodeoxyglycosylamines: Maillard reaction of 18F-fluorodeoxyglucose with biological amines.

    PubMed

    Baranwal, Aparna; Patel, Himika H; Mukherjee, Jogeshwar

    2014-02-01

    The Maillard reaction of sugars and amines resulting in the formation of glycosylamines and Amadori products is of biological significance, for drug delivery, role in central nervous system, and other potential applications. We have examined the interaction of (18) F-fluorodeoxyglucose ((18) F-FDG) with biological amines to study the formation of (18) F-fluorodeoxyglycosylamines ((18) F-FDGly). Respective amines N-allyl-2-aminomethylpyrrolidine (NAP) and 2-(4'-aminophenyl)-6-hydroxybenzothiazole (PIB precursor) were mixed with FDG to provide glycosylamines, FDGNAP and FDGBTA. Radiosynthesis using (18) F-FDG (2-5 mCi) was carried out to provide (18) F-FDGNAP and (18) F-FDGBTA. Binding of FDGBTA and (18) F-FDGBTA was evaluated in human brain sections of Alzheimer's disease (AD) patients and control subjects using autoradiography. Both FDGNAP and FDGBTA were isolated as stable products. Kinetics of (18) F-FDGNAP reaction indicated a significant product at 4 h (63% radiochemical yield). (18) F-FDGBTA was prepared in 57% yield. Preliminary studies of FDGBTA showed displacement of (3) H-PIB (reduced by 80%), and (18) F-FDGBTA indicated selective binding to Aβ-amyloid plaques present in postmortem AD human brain, with a gray matter ratio of 3 between the AD patients and control subjects. We have demonstrated that (18) F-FDG couples with amines under mild conditions to form (18) F-FDGly in a manner similar to click chemistry. Although these amine derivatives are stable in vitro, stability in vivo and selective binding is under investigation.

  16. Indirect voltammetric detection of fluoride ions in toothpaste on a comb-shaped interdigitated microelectrode array.

    PubMed

    Cernanská, Monika; Tomcík, Peter; Jánosíková, Zuzana; Rievaj, Miroslav; Bustin, Dusan

    2011-02-15

    A novel technique based on dynamic electrochemistry for the detection of fluoride ions was developed. It is based on its strong complexation with ferric ion. Formed fluoroferric complex is cathodically inactive at the potential of the reduction of free ferric aquo ion. The voltammetric and amperometric response of platinum comb-shaped interdigitated microelectrode array is decreased after fluoride addition. This decrease serves for the quantification of fluoride ions added to the solution. The detection limit of 4.5×10(-5) mol dm(-3) was achieved when one of the segments of interdigitated microelectrode array (IDA) was used as an indicating electrode. The detection limit is about one order of magnitude lower than in the case of conventional platinum macroelectrode. In comparison with ISE electrodes this method is faster and also avoiding large error resulting from the antilogarithmization of ISE Nerstian response. The method was applied to the analysis of toothpaste.

  17. Inhibition of Chloride Induced Crevice Corrosion in Alloy 22 by Fluoride Ions

    SciTech Connect

    Carranza, R M; Rodr?guez, M A; Rebak, R B

    2005-10-09

    Alloy 22 (N06022) is highly resistant to localized corrosion. Alloy 22 may be susceptible to crevice corrosion in pure chloride (Cl{sup -}) solutions under aggressive environmental conditions. The effect of the fluoride (F{sup -}) over the crevice corrosion induced by chloride ions is still not well established. The objective of the present work was to explore the crevice corrosion resistance of this alloy to different mixtures of fluorides and chlorides. Cyclic potentiodynamic polarization (CPP) tests were conducted in deaerated aqueous solutions of pure halide ions and also in different mixtures of chloride and fluoride at 90 C and pH 6. The range of chloride concentration [Cl{sup -}] was 0.001 M {le} [Cl{sup -}] {le} 1 M and the range of molar fluoride to chloride ratio [F{sup -}]/[Cl{sup -}] was 0.1 {le} [F{sup -}]/[Cl{sup -}] {le} 10. Results showed that Alloy 22 was susceptible to crevice corrosion in all the pure chloride solutions but not in the pure fluoride solutions. Fluoride ions showed an inhibitor behavior only in mixtures with a molar ratio [F{sup -}]/[Cl{sup -}] > 2. For mixtures with a molar ratio [F{sup -}]/[Cl{sup -}] of 7 and 10 the inhibition of crevice corrosion was complete.

  18. Efficient radiosynthesis and non-clinical safety tests of the TSPO radioprobe [(18)F]FEDAC: Prerequisites for clinical application.

    PubMed

    Kawamura, Kazunori; Kumata, Katsushi; Takei, Makoto; Furutsuka, Kenji; Hashimoto, Hiroki; Ito, Takehito; Shiomi, Satoshi; Fujishiro, Tomoya; Watanabe, Ryuji; Igarashi, Nobuyuki; Muto, Masatoshi; Yamasaki, Tomoteru; Yui, Joji; Xie, Lin; Hatori, Akiko; Zhang, Yiding; Nemoto, Kazuyoshi; Fujibayashi, Yasuhisa; Zhang, Ming-Rong

    2016-07-01

    [(18)F]FEDAC ([(18)F]1) has potent binding affinity and selectivity for translocator protein (18kDa, TSPO), and has been used to noninvasively visualize neuroinflammation, lung inflammation, acute liver damage, nonalcoholic fatty liver disease, and liver fibrosis. We had previously synthesized [(18)F]1 in two steps: (i) preparation of [(18)F]fluoroethyl bromide and (ii) coupling of [(18)F]fluoroethyl bromide with the appropriate precursor (2) for labeling. In this study, to clinically utilize [(18)F]1 as a PET radiopharmaceutical and to transfer the production technique of [(18)F]1 to other PET centers, we simplified its preparation by using a direct, one-step, tosyloxy-for-fluorine substitution. We also performed an acute toxicity study as a major non-clinical safety test, and determined radiometabolites using human liver microsomes. [(18)F]1 was prepared via direct (18)F-fluorination by heating the corresponding tosylated derivative (3) with [(18)F]fluoride as its Kryptofix 222 complex in dimethyl sulfoxide at 110°C for 15min, following by HPLC purification. Non-clinical safety tests were performed for the extended single-dose toxicity study in rats, and for the in vitro metabolite analysis with human liver microsomal incubation. High quality batches of [(18)F]1, compatible with clinical applications, were obtained. At the end of irradiation, the decay-corrected radiochemical yield of [(18)F]1 using 1 and 5mg of precursor based on [(18)F]fluoride was 18.5±7.9% (n=10) and 52.0±5.8% (n=3), respectively. A single-dose of [(18)F]1 did not show toxicological effects for 14 days after the injection in male and female rats. In human liver microsomal incubations, [(18)F]1 was easily metabolized to [(18)F]desbenzyl-FEDAC ([(18)F]10) by CYPs (4.2% of parent compound left 60min after incubation). We successfully synthesized clinical grade batches of [(18)F]1 and verified the absence of innocuity of this radiotracer. [(18)F]1 will be used to first-in-human studies in our

  19. Combinatorial incorporation of fluoride and cobalt ions into calcium phosphates to stimulate osteogenesis and angiogenesis.

    PubMed

    Birgani, Zeinab Tahmasebi; Gharraee, Nazli; Malhotra, Angad; van Blitterswijk, Clemens A; Habibovic, Pamela

    2016-02-29

    Bone healing requires two critical mechanisms, angiogenesis and osteogenesis. In order to improve bone graft substitutes, both mechanisms should be addressed simultaneously. While the individual effects of various bioinorganics have been studied, an understanding of the combinatorial effects is lacking. Cobalt and fluoride ions, in appropriate concentrations, are known to individually favor the vascularization and mineralization processes, respectively. This study investigated the potential of using a combination of fluoride and cobalt ions to simultaneously promote osteogenesis and angiogenesis in human mesenchymal stromal cells (hMSCs). Using a two-step biomimetic method, wells of tissue culture plates were coated with a calcium phosphate (CaP) layer without or with the incorporation of cobalt, fluoride, or both. In parallel, hMSCs were cultured on uncoated well plates, and cultured with cobalt and/or fluoride ions within the media. The results revealed that cobalt ions increased the expression of angiogenic markers, with the effects being stronger when the ions were added as a dissolved salt in cell medium as compared to incorporation into CaP. Cobalt ions generally suppressed the ALP activity, the expression of osteogenic genes, and the level of mineralization, regardless of delivery method. Fluoride ions, individually or in combination with cobalt, significantly increased the expression of many of the selected osteogenic markers, as well as mineral deposition. This study demonstrates an approach to simultaneously target the two essential mechanisms in bone healing: angiogenesis and osteogenesis. The incorporation of cobalt and fluoride into CaPs is a promising method to improve the biological performance of fully synthetic bone graft substitutes.

  20. Comparison of aluminum modified natural materials in the removal of fluoride ions.

    PubMed

    Teutli-Sequeira, A; Solache-Ríos, M; Martínez-Miranda, V; Linares-Hernández, I

    2014-03-15

    The removal behaviors of fluoride ions from aqueous solutions and drinking water by aluminum modified hematite, zeolitic tuff and calcite were determined. Drinking water containing naturally 8.29 mg of fluoride ions per liter was characterized. The hematite, zeolitic tuff and calcite were aluminum modified by an electrochemical method. The effects of contact time and the dose of adsorbent were determined. The PZC (point of zero charge) values for aluminum modified hematite, zeolitic tuff and calcite were 6.2, 5.8 and 8.4, respectively. Adsorption kinetic data were best fitted to pseudo-second-order and Elovich models and equilibrium data to Langmuir-Freundlich isotherm model. The highest fluoride sorption capacities (10.25 and 1.16 mg/g for aqueous solutions and drinking water respectively) were obtained for aluminum modified zeolite with an adsorbent dosage of 10 g/L and an initial F(-) concentration of 9 and 8.29 mg/L for aqueous solutions and drinking water respectively (the final concentrations were 0.08 and 0.7 mg/L respectively). The main mechanism involved in the adsorption of fluoride ions is chemisorption on heterogeneous materials according to the results obtained by fitting the data to kinetic and isotherm models respectively. Aluminum modified zeolitic tuff showed the best characteristics for the removal of fluoride ions from water.

  1. Naphthalenyl appended semicarbazone as ;turn on; fluorescent chemosensor for selective recognition of fluoride ion

    NASA Astrophysics Data System (ADS)

    Basheer, Sabeel M.; Haribabu, Jebiti; Bhuvanesh, Nattamai S. P.; Karvembu, Ramasamy; Sreekanth, Anandaram

    2017-10-01

    The reaction of 1-isocyanatonaphthalene with hydrazine hydrate in presence of acetone resulted in the formation of napthyl based semicarbazone (1). The compound has been characterized using UV-Visible, FT-IR, NMR, mass spectroscopic and single crystal X-ray diffraction (XRD) tools. The interaction between 1 and fluoride ion has been investigated by means of UV-Visible and fluorescence spectra. The fluoride ion sensing mechanism of 1 has been studied by hybrid density functional theory (DFT) and time dependent DFT (TD-DFT) methods. The added fluoride ion formed intermolecular hydrogen bonds with the protons of N1sbnd H1 and N2sbnd H2 groups of 1 in the ground state. The N1sbnd H1 proton which is closer to naphthalene moiety prefers to bind fluoride anion in the excited state after deprotonation, which lead to excited state proton transfer (ESPT). The fluoride ion sensing process shows a moderate (31.99 kcal/mol) Gibbs free energy. To understand the dynamic features, the transition state (TS) calculation is performed and the change in entropy is found to be -0.6259 kJ/mol, which shows that the sensing process is thermodynamically allowed.

  2. Development of gold standard ion-selective electrode-based methods for fluoride analysis.

    PubMed

    Martínez-Mier, E A; Cury, J A; Heilman, J R; Katz, B P; Levy, S M; Li, Y; Maguire, A; Margineda, J; O'Mullane, D; Phantumvanit, P; Soto-Rojas, A E; Stookey, G K; Villa, A; Wefel, J S; Whelton, H; Whitford, G M; Zero, D T; Zhang, W; Zohouri, V

    2011-01-01

    Currently available techniques for fluoride analysis are not standardized. Therefore, this study was designed to develop standardized methods for analyzing fluoride in biological and nonbiological samples used for dental research. A group of nine laboratories analyzed a set of standardized samples for fluoride concentration using their own methods. The group then reviewed existing analytical techniques for fluoride analysis, identified inconsistencies in the use of these techniques and conducted testing to resolve differences. Based on the results of the testing undertaken to define the best approaches for the analysis, the group developed recommendations for direct and microdiffusion methods using the fluoride ion-selective electrode. Initial results demonstrated that there was no consensus regarding the choice of analytical techniques for different types of samples. Although for several types of samples, the results of the fluoride analyses were similar among some laboratories, greater differences were observed for saliva, food and beverage samples. In spite of these initial differences, precise and true values of fluoride concentration, as well as smaller differences between laboratories, were obtained once the standardized methodologies were used. Intraclass correlation coefficients ranged from 0.90 to 0.93, for the analysis of a certified reference material, using the standardized methodologies. The results of this study demonstrate that the development and use of standardized protocols for F analysis significantly decreased differences among laboratories and resulted in more precise and true values. 2010 S. Karger AG, Basel.

  3. Development of Gold Standard Ion-Selective Electrode-Based Methods for Fluoride Analysis

    PubMed Central

    Martínez-Mier, E.A.; Cury, J.A.; Heilman, J.R.; Katz, B.P.; Levy, S.M.; Li, Y.; Maguire, A.; Margineda, J.; O’Mullane, D.; Phantumvanit, P.; Soto-Rojas, A.E.; Stookey, G.K.; Villa, A.; Wefel, J.S.; Whelton, H.; Whitford, G.M.; Zero, D.T.; Zhang, W.; Zohouri, V.

    2011-01-01

    Background/Aims: Currently available techniques for fluoride analysis are not standardized. Therefore, this study was designed to develop standardized methods for analyzing fluoride in biological and nonbiological samples used for dental research. Methods A group of nine laboratories analyzed a set of standardized samples for fluoride concentration using their own methods. The group then reviewed existing analytical techniques for fluoride analysis, identified inconsistencies in the use of these techniques and conducted testing to resolve differences. Based on the results of the testing undertaken to define the best approaches for the analysis, the group developed recommendations for direct and microdiffusion methods using the fluoride ion-selective electrode. Results Initial results demonstrated that there was no consensus regarding the choice of analytical techniques for different types of samples. Although for several types of samples, the results of the fluoride analyses were similar among some laboratories, greater differences were observed for saliva, food and beverage samples. In spite of these initial differences, precise and true values of fluoride concentration, as well as smaller differences between laboratories, were obtained once the standardized methodologies were used. Intraclass correlation coefficients ranged from 0.90 to 0.93, for the analysis of a certified reference material, using the standardized methodologies. Conclusion The results of this study demonstrate that the development and use of standardized protocols for F analysis significantly decreased differences among laboratories and resulted in more precise and true values. PMID:21160184

  4. Ion release, fluoride charge of and adhesion of an orthodontic cement paste containing microcapsules.

    PubMed

    Burbank, Brant D; Slater, Michael; Kava, Alyssa; Doyle, James; McHale, William A; Latta, Mark A; Gross, Stephen M

    2016-02-01

    Dental materials capable of releasing calcium, phosphate and fluoride are of great interest for remineralization. Microencapsulated aqueous solutions of these ions in orthodontic cement demonstrate slow, sustained release by passive diffusion through a permeable membrane without the need for dissolution or etching of fillers. The potential to charge a dental material formulated with microencapsulated water with fluoride by toothbrushing with over the counter toothpaste and the effect of microcapsules on cement adhesion to enamel was determined. Orthodontic cements that contained microcapsules with water and controls without microcapsules were brushed with over-the-counter toothpaste and fluoride release was measured. Adhesion measurements were performed loading orthodontic brackets to failure. Cements that contained microencapsulated solutions of 5.0M Ca(NO3)2, 0.8M NaF, 6.0MK2HPO4 or a mixture of all three were prepared. Ion release profiles were measured as a function of time. A greater fluoride charge and re-release from toothbrushing was demonstrated compared to a control with no microcapsules. Adhesion of an orthodontic cement that contained microencapsulated remineralizing agents was 8.5±2.5MPa compared to the control without microcapsules which was of 8.3±1.7MPa. Sustained release of fluoride, calcium and phosphate ions from cement formulated with microencapsulated remineralizing agents was demonstrated. Orthodontic cements with microcapsules show a release of bioavailable fluoride, calcium, and phosphate ions near the tooth surface while having the ability to charge with fluoride and not effect the adhesion of the material to enamel. Incorporation of microcapsules in dental materials is promising for promoting remineralization. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. GMP-compliant radiosynthesis of [18F]altanserin and human plasma metabolite studies.

    PubMed

    Hasler, F; Kuznetsova, O F; Krasikova, R N; Cservenyak, T; Quednow, B B; Vollenweider, F X; Ametamey, S M; Westera, G

    2009-04-01

    [(18)F]altanserin is the preferred radiotracer for in-vivo labeling of serotonin 2A receptors by positron emission tomography (PET). We report a modified synthesis procedure suited for reliable production of multi-GBq amounts of [(18)F]altanserin useful for application in humans. We introduced thermal heating for drying of [(18)F]fluoride as well as for the reaction instead of microwave heating. We furthermore describe solid phase extraction and HPLC procedures for quantitative determination of [(18)F]altanserin and metabolites in plasma. The time course of arterial plasma activity with and without metabolite correction was determined. 90 min after bolus injection, 38.4% of total plasma activity derived from unchanged [(18)F]altanserin. Statistical comparison of kinetic profiles of [(18)F]altanserin metabolism in plasma samples collected in the course of two ongoing studies employing placebo, the serotonin releaser dexfenfluramine and the hallucinogen psilocybin, revealed the same tracer metabolism. We conclude that metabolite analysis for correction of individual plasma input functions used in tracer modeling is not necessary for [(18)F]altanserin studies involving psilocybin or dexfenfluramine treatment.

  6. Two years of experience with the [ 18F]FDG production module

    NASA Astrophysics Data System (ADS)

    Kim, Sang Wook; Hur, Min Goo; Chai, Jong-Seo; Park, Jeong Hoon; Yu, Kook Hyun; Jeong, Cheol Ki; Lee, Goung Jin; Min, Young Don; Yang, Seung Dae

    2007-08-01

    Chemistry module for a conventional [18F]FDG production by using tetrabutylammonium bicarbonate (TBA) and an acidic hydrolysis has been manufactured and evaluated. In this experiment, 75 mM (pH 7.5-7.8) of TBA solution and a ca. 2-curies order of [18F]-fluoride have been used for the evaluation. The commercial acidic purification cartridge was purchased from GE or UKE. The operation system (OS) was programmed with Lab-View which was selected because of its easy customization of the OS. Small sized solenoid valves (Burkert; type 6124) were selected to reduce the module dimensions (W 350 × D 270 × H 250). The total time for the synthesis of [18F]FDG was 30 ± 3 min. The production yield of [18F]FDG was 60 ± 2% on an average at EOS, with the decay uncorrected. This experimental data show that the traditional chemistry module can provide a good [18F]FDG production yield by optimizing the operational conditions. The radiochemical purity, radionuclidic purity, acidity, residual solvent, osmolality and endotoxin were determined to assess the quality of [18F]FDG. The examined contents for the quality control of [18F]FDG were found to be suitable for a clinical application.

  7. Al[18F]NOTA-T140 Peptide for Noninvasive Visualization of CXCR4 Expression

    PubMed Central

    Yan, Xuefeng; Niu, Gang; Wang, Zhe; Yang, Xiangyu; Kiesewetter, Dale O.; Jacobson, Orit; Shen, Baozhong; Chen, Xiaoyuan

    2017-01-01

    Purpose Chemokine receptor CXCR4 plays an important role in tumor aggressiveness, invasiveness, and metastasis formation. Quantification of CXCR4 expression by tumors may have an impact on prediction and evaluation of tumor response to therapies. In this study, we developed a robust and straightforward F-18 labeling route of T140, a CXCR4 peptide-based antagonist. Procedures T140 derivative was conjugated to 1,4,7-triazacyclononane-triacetic acid (NOTA) and labeled with Al[18F]. Al[18F]NOTA-T140 was evaluated in vitro in cell-based assay and stability in mouse serum and in vivo using CXCR4 positive and negative tumor xenograft models. Results Labeling of Al[18F]NOTA-T140 was completed within 30 min with a radiochemical yield of 58±5.3 % at the end of synthesis, based on fluoride-18 activity. Al[18F]NOTA-T140 accumulated in CHO-CXCR4 positive but not negative tumors. Al[18F]NOTA-T140 uptake in the tumors correlated with CXCR4 protein expression. Moreover, Al[18F]NOTA-T140 had high accumulation in CXCR4-positive metastatic tumors. Conclusions The simplicity of Al[18F]NOTA-T140 labeling along with its properties to specifically image CXCR4 expression by tumors warrant further clinical application for the diagnosis of CXCR4 clinically. PMID:26126597

  8. Al[18F]NOTA-T140 Peptide for Noninvasive Visualization of CXCR4 Expression.

    PubMed

    Yan, Xuefeng; Niu, Gang; Wang, Zhe; Yang, Xiangyu; Kiesewetter, Dale O; Jacobson, Orit; Shen, Baozhong; Chen, Xiaoyuan

    2016-02-01

    Chemokine receptor CXCR4 plays an important role in tumor aggressiveness, invasiveness, and metastasis formation. Quantification of CXCR4 expression by tumors may have an impact on prediction and evaluation of tumor response to therapies. In this study, we developed a robust and straightforward F-18 labeling route of T140, a CXCR4 peptide-based antagonist. T140 derivative was conjugated to 1,4,7-triazacyclononane-triacetic acid (NOTA) and labeled with Al[(18)F]. Al[(18)F]NOTA-T140 was evaluated in vitro in cell-based assay and stability in mouse serum and in vivo using CXCR4 positive and negative tumor xenograft models. Labeling of Al[(18)F]NOTA-T140 was completed within 30 min with a radiochemical yield of 58 ± 5.3 % at the end of synthesis, based on fluoride-18 activity. Al[(18)F]NOTA-T140 accumulated in CHO-CXCR4 positive but not negative tumors. Al[(18)F]NOTA-T140 uptake in the tumors correlated with CXCR4 protein expression. Moreover, Al[(18)F]NOTA-T140 had high accumulation in CXCR4-positive metastatic tumors. The simplicity of Al[(18)F]NOTA-T140 labeling along with its properties to specifically image CXCR4 expression by tumors warrant further clinical application for the diagnosis of CXCR4 clinically.

  9. Iodonium Ylide Mediated Radiofluorination of 18F-FPEB and Validation for Human Use

    PubMed Central

    Stephenson, Nickeisha A.; Holland, Jason P.; Kassenbrock, Alina; Yokell, Daniel L.; Livni, Eli; Liang, Steven H.; Vasdev, Neil

    2016-01-01

    Translation of new methodologies for labeling non-activated aromatic molecules with fluorine-18 remains a challenge. Here, we report a one-step, regioselective, metal-free 18F-labeling method that employs a hypervalent iodonium(III) ylide precursor, to prepare the radiopharmaceutical 18F-FPEB. Methods Automated radiosynthesis of 18F-FPEB was achieved by reaction of the ylide precursor (4 mg) with 18F-NEt4F in DMF at 80 °C for 5 minutes, and formulated for injection within 1 hour. Results 18F-FPEB was synthesized in 15 – 25% (n = 3) uncorrected radiochemical yields relative to 18F-fluoride, with specific activities of 666 ± 51.8 GBq/μmol (18 ± 1.4 Ci/μmol) at the end-of-synthesis (EOS). The radiopharmaceutical was validated for human use. Conclusions Radiofluorination of iodonium (III) ylides proved to be an efficient radiosynthetic strategy for synthesis of 18F-labeled radiopharmaceuticals. PMID:25655630

  10. 18F-Labeling Using Click Cycloadditions

    PubMed Central

    Ross, Tobias L.

    2014-01-01

    Due to expanding applications of positron emission tomography (PET) there is a demand for developing new techniques to introduce fluorine-18 (t 1/2 = 109.8 min). Considering that most novel PET tracers are sensitive biomolecules and that direct introduction of fluorine-18 often needs harsh conditions, the insertion of 18F in those molecules poses an exceeding challenge. Two major challenges during 18F-labeling are a regioselective introduction and a fast and high yielding way under mild conditions. Furthermore, attention has to be paid to functionalities, which are usually present in complex structures of the target molecule. The Cu-catalyzed azide-alkyne cycloaddition (CuAAC) and several copper-free click reactions represent such methods for radiolabeling of sensitive molecules under the above-mentioned criteria. This minireview will provide a quick overview about the development of novel 18F-labeled prosthetic groups for click cycloadditions and will summarize recent trends in copper-catalyzed and copper-free click 18F-cycloadditions. PMID:25003110

  11. COMPRESSIVE FATIGUE IN TITANIUM DENTAL IMPLANTS SUBMITTED TO FLUORIDE IONS ACTION

    PubMed Central

    Ribeiro, Ana Lúcia Roselino; Noriega, Jorge Roberto; Dametto, Fábio Roberto; Vaz, Luís Geraldo

    2007-01-01

    The aim of this study was to assess the influence of a fluoridated medium on the mechanical properties of an internal hexagon implant-abutment set, by means of compression, mechanical cycling and metallographic characterization by scanning electronic microscopy. Five years of regular use of oral hygiene with a sodium fluoride solution content of 1500 ppm were simulated, immersing the samples in this medium for 184 hours, with the solutions being changed every 12 hours. Data were analyzed at a 95% confidence level with Fisher's exact test. After the action of fluoride ions, a negative influence occurred in the mechanical cycling test performed in a servohydraulic machine (Material Test System-810) set to a frequency of 15 Hz with 100,000 cycles and programmed to 60% of the maximum resistance of static compression test. The sets tended to fracture by compression on the screw, characterized by mixed ruptures with predominance of fragile fracture, as observed by microscopy. An evidence of corrosion by pitting on sample surfaces was found after the fluoride ions action. It may be concluded that prolonged contact with fluoride ions is harmful to the mechanical properties of commercially pure titanium structures. PMID:19089148

  12. [Automated synthesis of 2-[(18)F]-fluoro-2-deoxy-D-glucose by on-column hydrolysis].

    PubMed

    Luo, Lei; Tang, Ganghua; Tang, Xiaolan

    2009-11-01

    To study automated synthesis of 2-[(18)F]-fluoro-2-deoxy-D-glucose ((18)F-FDG) via on-column hydrolysis. Automated synthesis of (18)F-FDG was performed by the on-column hydrolysis procedure in TRACERlab FXF-N synthesizer. (18)F-FDG injection was obtained via nucleophilic fluorination of 1, 3, 4, 6-tetra-O-acetyl-2-O-trifluoromethanesulfony-beta-D-mannopyranose as the precursor molecule with (18)F-fluoride, hydrolysis of the (18)F-labeled intermediate on SEP-PAK C18 cartridges with 2 mol/L NaOH solution, and purification and neutralization with SEP-PAK cartridges. The uncorrected radiochemical yield of (18)F-FDG was more than 60% within the total synthesis time shorter than 20 min. The radiochemical purity of (18)F-FDG was above 99%. On-column hydrolysis is simple and practical for the automated synthesis of (18)F-FDG. (18)F-FDG injection produced by this procedure can be used in clinical PET imaging.

  13. Future imaging of atherosclerosis: molecular imaging of coronary atherosclerosis with 18F positron emission tomography

    PubMed Central

    Psaltis, Peter J.

    2016-01-01

    Atherosclerosis is characterized by the formation of complex atheroma lesions (plaques) in arteries that pose risk by their flow-limiting nature and propensity for rupture and thrombotic occlusion. It develops in the context of disturbances to lipid metabolism and immune response, with inflammation underpinning all stages of plaque formation, progression and rupture. As the primary disease process responsible for myocardial infarction, stroke and peripheral vascular disease, atherosclerosis is a leading cause of morbidity and mortality on a global scale. A precise understanding of its pathogenic mechanisms is therefore critically important. Integral to this is the role of vascular wall imaging. Over recent years, the rapidly evolving field of molecular imaging has begun to revolutionize our ability to image beyond just the anatomical substrate of vascular disease, and more dynamically assess its pathobiology. Nuclear imaging by positron emission tomography (PET) can target specific molecular and biological pathways involved in atherosclerosis, with the application of 18Fluoride PET imaging being widely studied for its potential to identify plaques that are vulnerable or high risk. In this review, we discuss the emergence of 18Fluoride PET as a promising modality for the assessment of coronary atherosclerosis, focusing on the strengths and limitations of the two main radionuclide tracers that have been investigated to date: 2-deoxy-2-(18F)fluoro-D-glucose (18F-FDG) and sodium 18F-fluoride (18F-NaF). PMID:27500093

  14. Radiosynthesis and initial evaluation of [18F]-FEPPA for PET imaging of peripheral benzodiazepine receptors.

    PubMed

    Wilson, Alan A; Garcia, Armando; Parkes, Jun; McCormick, Patrick; Stephenson, Karin A; Houle, Sylvain; Vasdev, Neil

    2008-04-01

    A novel [18F]-radiolabelled phenoxyanilide, [18F]-FEPPA, has been synthesized and evaluated, in vitro and ex vivo, as a potential positron emission tomography imaging agent for the peripheral benzodiazepine receptor (PBR). [18F]-FEPPA and two other radiotracers for imaging PBR, namely [11C]-PBR28 and [11C]-PBR28-d3, were synthesised and evaluated in vitro and ex vivo as potential PBR imaging agents. [18F]-FEPPA is efficiently prepared in one step from its tosylate precursor and [18F]-fluoride in high radiochemical yields and at high specific activity. FEPPA displayed a Ki of 0.07 nM for PBR in rat mitochondrial membrane preparations and a suitable lipophilicity for brain penetration (log P of 2.99 at pH 7.4). Upon intravenous injection into rats, [18F]-FEPPA showed moderate brain uptake [standard uptake value (SUV) of 0.6 at 5 min] and a slow washout (SUV of 0.35 after 60 min). Highest uptake of radioactivity was seen in the hypothalamus and olfactory bulb, regions previously reported to be enriched in PBR in rat brain. Analysis of plasma and brain extracts demonstrated that [18F]-FEPPA was rapidly metabolized, but no lipophilic metabolites were observed in either preparation and only 5% radioactive metabolites were present in brain tissue extracts. Blocking studies to determine the extent of specific binding of [18F]-FEPPA in rat brain were problematic due to large perturbations in circulating radiotracer and the lack of a reference region. Further evaluation of the potential of [18F]-FEPPA will require the employment of rigorous kinetic models and/or appropriate animal models.

  15. Fluoride ion contamination in the groundwater of Mithi sub-district, the Thar Desert, Pakistan

    NASA Astrophysics Data System (ADS)

    Rafique, Tahir; Naseem, Shahid; Bhanger, Muhammad I.; Usmani, Tanzil H.

    2008-11-01

    Groundwater samples were collected from various localities of Mithi sub-district of the Thar Desert of Pakistan and analysed for fluoride ion along with other chemical parameters. The area is mainly covered by sand dunes and kaolin/granite at variable depths. Results showed that collected water samples were severely contaminated by the presence of fluoride ion and most of the samples have higher concentration than prescribed WHO standards (1.5 mg/l) for drinking water. Fluoride ion concentrations ranged between 0.09 and 11.63 mg/l with mean and median values of 3.64 and 3.44 mg/l, respectively, in this area whereas, distribution pattern showed high concentrations in the vicinity of Islamkot and Mithi towns. The content of F- has also been correlated with other major ions found in the groundwater of the study area. The positive correlation of F- with Na+ and HCO3 - showed that the water with high Na+ and HCO3 - stabilizes F- ions in the groundwater of the Thar Desert. The pH versus F- plots signifies high fluoride concentration at higher pH values, implying that alkaline environment favours the replacement of exchangeable OH- with F- in the groundwater of Mithi area. The saturation indices (SI) of fluorite (CaF2) and calcite (CaCO3) in the groundwater samples showed that most of the samples are oversaturated with respect to calcite whereas majority of samples have been found under saturated with respect to fluorite. The log TDS and Na/Na+Ca ratio reflected supremacy of weathering of rocks, which promotes the availability of fluoride ions in the groundwater. Piper diagram has been used to classify the hydrofacies. In the cation triangle, all samples are Na-type, while the anion triangle reflects major dominance of Cl-type with a minor influence of HCO3 - and SO4 -.

  16. Nuclear quantum effects in water exchange around lithium and fluoride ions.

    PubMed

    Wilkins, David M; Manolopoulos, David E; Dang, Liem X

    2015-02-14

    We employ classical and ring polymer molecular dynamics simulations to study the effect of nuclear quantum fluctuations on the structure and the water exchange dynamics of aqueous solutions of lithium and fluoride ions. While we obtain reasonably good agreement with experimental data for solutions of lithium by augmenting the Coulombic interactions between the ion and the water molecules with a standard Lennard-Jones ion-oxygen potential, the same is not true for solutions of fluoride, for which we find that a potential with a softer repulsive wall gives much better agreement. A small degree of destabilization of the first hydration shell is found in quantum simulations of both ions when compared with classical simulations, with the shell becoming less sharply defined and the mean residence time of the water molecules in the shell decreasing. In line with these modest differences, we find that the mechanisms of the exchange processes are unaffected by quantization, so a classical description of these reactions gives qualitatively correct and quantitatively reasonable results. We also find that the quantum effects in solutions of lithium are larger than in solutions of fluoride. This is partly due to the stronger interaction of lithium with water molecules, partly due to the lighter mass of lithium and partly due to competing quantum effects in the hydration of fluoride, which are absent in the hydration of lithium.

  17. Nuclear quantum effects in water exchange around lithium and fluoride ions

    SciTech Connect

    Wilkins, David M.; Manolopoulos, David; Dang, Liem X.

    2015-02-14

    We employ classical and ring polymer molecular dynamics simulations to study the effect of nuclear quantum fluctuations on the structure and the water exchange dynamics of aqueous solutions of lithium and fluoride ions. While we obtain reasonably good agreement with experimental data for solutions of lithium by augmenting the Coulombic interactions between the ion and the water molecules with a standard Lennard-Jones ion-oxygen potential, the same is not true for solutions of fluoride, for which we find that a potential with a softer repulsive wall gives much better agreement. A small degree of destabilization of the first hydration shell is found in quantum simulations of both ions when compared with classical simulations, with the shell becoming less sharply defined and the mean residence time of the water molecules in the shell decreasing. In line with these modest differences, we find that the mechanisms of the water exchange reactions are unaffected by quantization, so a classical description of these reactions gives qualitatively correct and quantitatively reasonable results. We also find that the quantum effects in solutions of lithium are larger than in solutions of fluoride. This is partly due to the stronger interaction of lithium with water molecules, partly due to the lighter mass of lithium, and partly due to competing quantum effects in the hydration of fluoride, which are absent in the hydration of lithium. LXD was supported by US Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences.

  18. Nuclear quantum effects in water exchange around lithium and fluoride ions

    SciTech Connect

    Wilkins, David M.; Manolopoulos, David E.; Dang, Liem X.

    2015-02-14

    We employ classical and ring polymer molecular dynamics simulations to study the effect of nuclear quantum fluctuations on the structure and the water exchange dynamics of aqueous solutions of lithium and fluoride ions. While we obtain reasonably good agreement with experimental data for solutions of lithium by augmenting the Coulombic interactions between the ion and the water molecules with a standard Lennard-Jones ion-oxygen potential, the same is not true for solutions of fluoride, for which we find that a potential with a softer repulsive wall gives much better agreement. A small degree of destabilization of the first hydration shell is found in quantum simulations of both ions when compared with classical simulations, with the shell becoming less sharply defined and the mean residence time of the water molecules in the shell decreasing. In line with these modest differences, we find that the mechanisms of the exchange processes are unaffected by quantization, so a classical description of these reactions gives qualitatively correct and quantitatively reasonable results. We also find that the quantum effects in solutions of lithium are larger than in solutions of fluoride. This is partly due to the stronger interaction of lithium with water molecules, partly due to the lighter mass of lithium and partly due to competing quantum effects in the hydration of fluoride, which are absent in the hydration of lithium.

  19. Automated radiosynthesis of [(18)F]ciprofloxacin.

    PubMed

    Stanek, Johann; Mairinger, Severin; Wanek, Thomas; Kuntner, Claudia; Müller, Markus; Langer, Oliver

    2015-05-01

    We transferred the previously published manual synthesis of [(18)F]ciprofloxacin (decay-corrected RCY: 5.5±1.0%) to an automated synthesis module (TRACERlab(TM) FXFDG, GE Healthcare) and observed a strong decrease in RCY (0.4±0.4%). When replacing the standard 15-mL glassy carbon reactor of the synthesis module with a 3-mL V-shaped borosilicate glass reactor a considerable improvement in RCY was observed. [(18)F]Ciprofloxacin was obtained in a RCY of 2.7±1.4% (n=23) with a specific activity at EOS of 1.4±0.5GBq/µmol in a synthesis time of 160min. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Synthesis and Evaluation in Monkey of [18F]4-Fluoro-N-methyl-N-(4-(6- (methylamino)pyrimidin-4-yl)thiazol-2-yl)benzamide ([18F]FIMX), a Promising Radioligand for PET Imaging of Brain Metabotropic Glutamate Receptor 1 (mGluR1)

    PubMed Central

    Xu, Rong; Zanotti-Fregonara, Paolo; Zoghbi, Sami S.; Gladding, Robert L.; Woock, Alicia; Innis, Robert B.; Pike, Victor W

    2013-01-01

    We sought to develop a PET radioligand that would be useful for imaging human brain metabotropic subtype 1 receptors (mGluR1) in neuropsychiatric disorders and in drug development. 4-Fluoro-N-methyl-N-(4-(6-(methylamino)pyrimidin-4-yl)thiazol-2-yl)benzamide (FIMX, 11) was identified as having favorable properties for development as a PET radioligand. We developed a method for preparing [18F]11 in useful radiochemical yield and in high specific activity from [18F]fluoride ion and an N-Boc-protected (phenyl)aryliodonium salt precursor (15). In baseline experiments in rhesus monkey, [18F]11 gave high brain radioactivity uptake reflecting the expected distribution of mGluR1 with notably high uptake in cerebellum which became 47% lower by 120 min after radioligand injection. Pharmacological challenges demonstrated a very high proportion of the radioactivity in monkey brain to be bound specifically and reversibly to mGluR1. [18F]11 is concluded to be an effective PET radioligand for imaging mGluR1 in monkey brain and therefore merits further evaluation in human subjects. PMID:24147864

  1. Automated synthesis of N-(2-[(18) F]Fluoropropionyl)-L-glutamic acid as an amino acid tracer for tumor imaging on a modified [(18) F]FDG synthesis module.

    PubMed

    Liu, Shaoyu; Sun, Aixia; Zhang, Zhanwen; Tang, Xiaolan; Nie, Dahong; Ma, Hui; Jiang, Shende; Tang, Ganghua

    2017-04-03

    N-(2-[(18) F]Fluoropropionyl)-L-glutamic acid ([(18) F]FPGLU) is a potential amino acid tracer for tumor imaging with positron emission tomography (PET). However, due to the complicated multi-step synthesis, the routine production of [(18) F]FPGLU presents many challenging laboratory requirements. In order to simplify the synthesis process of this interesting radiopharmaceutical, an efficient automated synthesis of [(18) F]FPGLU was performed on a modified commercial FDG synthesizer via a two-step on-column hydrolysis procedure, including (18) F-fluorination and on-column hydrolysis reaction. [(18) F]FPGLU was synthesized in 12 ± 2% (n = 10, uncorrected) radiochemical yield based on [(18) F]fluoride using the tosylated precursor 2. The radiochemical purity was ≥98%, and the overall synthesis time was 35 min. To further optimize the radiosynthesis conditions of [(18) F]FPGLU, a brominated precursor 3 was also used for the preparation of [(18) F]FPGLU and the improved radiochemical yield was up to 20 ± 3% (n = 10, uncorrected) in 35 min. Moreover, all these results were achieved using the similar on-column hydrolysis procedure on the modified FDG synthesis module.

  2. Dual acquisition of 18F-FMISO and 18F-FDOPA

    NASA Astrophysics Data System (ADS)

    Bell, Christopher; Rose, Stephen; Puttick, Simon; Pagnozzi, Alex; Poole, Christopher M.; Gal, Yaniv; Thomas, Paul; Fay, Michael; Jeffree, Rosalind L.; Dowson, Nicholas

    2014-07-01

    Metabolic imaging using positron emission tomography (PET) has found increasing clinical use for the management of infiltrating tumours such as glioma. However, the heterogeneous biological nature of tumours and intrinsic treatment resistance in some regions means that knowledge of multiple biological factors is needed for effective treatment planning. For example, the use of 18F-FDOPA to identify infiltrative tumour and 18F-FMISO for localizing hypoxic regions. Performing multiple PET acquisitions is impractical in many clinical settings, but previous studies suggest multiplexed PET imaging could be viable. The fidelity of the two signals is affected by the injection interval, scan timing and injected dose. The contribution of this work is to propose a framework to explicitly trade-off signal fidelity with logistical constraints when designing the imaging protocol. The particular case of estimating 18F-FMISO from a single frame prior to injection of 18F-FDOPA is considered. Theoretical experiments using simulations for typical biological scenarios in humans demonstrate that results comparable to a pair of single-tracer acquisitions can be obtained provided protocol timings are carefully selected. These results were validated using a pre-clinical data set that was synthetically multiplexed. The results indicate that the dual acquisition of 18F-FMISO and 18F-FDOPA could be feasible in the clinical setting. The proposed framework could also be used to design protocols for other tracers.

  3. A selective chemosensor for fluoride ion and its interaction with Calf Thymus DNA

    NASA Astrophysics Data System (ADS)

    Ghosh, Soumen; Al Masum, Abdulla; Ganguly, Aniruddha; Islam, Md. Maidul; Alam, Md. Akhtarul; Guchhait, Nikhil

    2017-05-01

    The amido-Schiff base 1 (N1, N3-bis (2-nitrobenzylidene)benzene-1,3-dicabohydrazide) containing a sbnd CONHsbnd group and sbnd CHdbnd Nsbnd linkage has been synthesized by the condensation between isophthalic acid dihydrazide and o-nitrobenzaldehyde. This molecule can act as a fluoride ion sensor with high selectivity and sensitivity. Presence of nitro group in the phenyl ring may be responsible for the detection of fluoride ion visually with a dramatic color change from colorless to deep red in aqueous dimethyl sulphoxide solution. This Schiff base can be used as test kit for sensing of fluoride ion in the solid state. Compound 1 can detect fluoride also in commercially available toothpaste. As the compound has adequate solubility in DMSO-water mixture (7:93, v/v) and having some hydrogen bond donor and acceptor centers, we have investigated its nature of binding with Calf Thymus-DNA (CT-DNA) using theoretical molecular modelling and other experimental methods like UV-vis spectroscopy, circular dichroic and thermal melting studies. Thermodynamic parameters have been obtained using the well known Van't Hoff's equation. From both theoretical and experimental findings it has been observed that it can interact effectively with CT-DNA with binding energy - 7.55 kcal/mol to - 7.50 kcal/mol.

  4. Ammonium Fluoride Mediated Synthesis of Anhydrous Metal Fluoride-Mesoporous Carbon Nanocomposites for High-Performance Lithium Ion Battery Cathodes.

    PubMed

    Chun, Jinyoung; Jo, Changshin; Sahgong, Sunhye; Kim, Min Gyu; Lim, Eunho; Kim, Dong Hyeon; Hwang, Jongkook; Kang, Eunae; Ryu, Keun Ah; Jung, Yoon Seok; Kim, Youngsik; Lee, Jinwoo

    2016-12-28

    Metal fluorides (MFx) are one of the most attractive cathode candidates for Li ion batteries (LIBs) due to their high conversion potentials with large capacities. However, only a limited number of synthetic methods, generally involving highly toxic or inaccessible reagents, currently exist, which has made it difficult to produce well-designed nanostructures suitable for cathodes; consequently, harnessing their potential cathodic properties has been a challenge. Herein, we report a new bottom-up synthetic method utilizing ammonium fluoride (NH4F) for the preparation of anhydrous MFx (CuF2, FeF3, and CoF2)/mesoporous carbon (MSU-F-C) nanocomposites, whereby a series of metal precursor nanoparticles preconfined in mesoporous carbon were readily converted to anhydrous MFx through simple heat treatment with NH4F under solventless conditions. We demonstrate the versatility, lower toxicity, and efficiency of this synthetic method and, using XRD analysis, propose a mechanism for the reaction. All MFx/MSU-F-C prepared in this study exhibited superior electrochemical performances, through conversion reactions, as the cathode for LIBs. In particular, FeF3/MSU-F-C maintained a capacity of 650 mAh g(-1)FeF3 across 50 cycles, which is ∼90% of its initial capacity. We expect that this facile synthesis method will trigger further research into the development of various nanostructured MFx for use in energy storage and other applications.

  5. Ion spatial distributions at the liquid-vapor interface of aqueous potassium fluoride solutions.

    PubMed

    Brown, Matthew A; D'Auria, Raffaella; Kuo, I-F William; Krisch, Maria J; Starr, David E; Bluhm, Hendrik; Tobias, Douglas J; Hemminger, John C

    2008-08-28

    X-Ray photoemission spectroscopy operating under ambient pressure conditions is used to probe ion distributions throughout the interfacial region of a free-flowing aqueous liquid micro-jet of 6 M potassium fluoride. Varying the energy of the ejected photoelectrons by carrying out experiments as a function of X-ray wavelength measures the composition of the aqueous-vapor interfacial region at various depths. The F(-) to K(+) atomic ratio is equal to unity throughout the interfacial region to a depth of 2 nm. The experimental ion profiles are compared with the results of a classical molecular dynamics simulation of a 6 M aqueous KF solution employing polarizable potentials. The experimental results are in qualitative agreement with the simulations when integrated over an exponentially decaying probe depth characteristic of an APPES experiment. First principles molecular dynamics simulations have been used to calculate the potential of mean force for moving a fluoride anion across the air-water interface. The results show that the fluoride anion is repelled from the interface, consistent with the depletion of F(-) at the interface revealed by the APPES experiment and polarizable force field-based molecular dynamics simulation. Together, the APPES and MD simulation data provide a detailed description of the aqueous-vapor interface of alkali fluoride systems. This work offers the first direct observation of the ion distribution at an aqueous potassium fluoride solution interface. The current experimental results are compared to those previously obtained for saturated solutions of KBr and KI to underscore the strong difference in surface propensity between soft/large and hard/small halide ions in aqueous solution.

  6. Ion spatial distributions at the liquid-vapor interface of aqueous potassium fluoride solutions

    SciTech Connect

    Brown, M A; D'Auria, R; Kuo, I W; Krisch, M J; Starr, D E; Bluhm, H; Tobias, D J; Hemminger, J C

    2008-04-23

    X-ray photoemission spectroscopy operating under ambient pressure conditions is used to probe ion distributions throughout the interfacial region of a free-flowing aqueous liquid micro-jet of 6 M potassium fluoride. Varying the energy of the ejected photoelectrons by carrying out experiments as a function of x-ray wavelength measures the composition of the aqueous-vapor interfacial region at various depths. The F{sup -} to K{sup +} atomic ratio is equal to unity throughout the interfacial region to a depth of 2 nm. The experimental ion profiles are compared with the results of a classical molecular dynamics simulation of a 6 M aqueous KF solution employing polarizable potentials. The experimental results are in qualitative agreement with the simulations when integrated over an exponentially decaying probe depth characteristic of an APPES experiment. First principles molecular dynamics simulations have been used to calculate the potential of mean force for moving a fluoride anion across the air-water interface. The results show that the fluoride anion is repelled from the interface, and this is consistent with the depletion of F{sup -} at the interface revealed by the APPES experiment and polarizable force field-based molecular dynamics simulation. Together, the APPES and MD simulation data provide a detailed description of the aqueous-vapor interface of alkali fluoride systems. This work offers the first direct observation of the ion distribution at a potassium fluoride aqueous solution interface. The current experimental results are compared to those previously obtained for saturated solutions of KBr and KI to underscore the strong difference in surface propensity between soft/large and hard/small halide ions in aqueous solution.

  7. Al18F-Labeling Of Heat-Sensitive Biomolecules for Positron Emission Tomography Imaging

    PubMed Central

    Cleeren, Frederik; Lecina, Joan; Ahamed, Muneer; Raes, Geert; Devoogdt, Nick; Caveliers, Vicky; McQuade, Paul; Rubins, Daniel J; Li, Wenping; Verbruggen, Alfons; Xavier, Catarina; Bormans, Guy

    2017-01-01

    Positron emission tomography (PET) using radiolabeled biomolecules is a translational molecular imaging technology that is increasingly used in support of drug development. Current methods for radiolabeling biomolecules with fluorine-18 are laborious and require multistep procedures with moderate labeling yields. The Al18F-labeling strategy involves chelation in aqueous medium of aluminum mono[18F]fluoride ({Al18F}2+) by a suitable chelator conjugated to a biomolecule. However, the need for elevated temperatures (100-120 °C) required for the chelation reaction limits its widespread use. Therefore, we designed a new restrained complexing agent (RESCA) for application of the AlF strategy at room temperature. Methods. The new chelator RESCA was conjugated to three relevant biologicals and the constructs were labeled with {Al18F}2+ to evaluate the generic applicability of the one-step Al18F-RESCA-method. Results. We successfully labeled human serum albumin with excellent radiochemical yields in less than 30 minutes and confirmed in vivo stability of the Al18F-labeled protein in rats. In addition, we efficiently labeled nanobodies targeting the Kupffer cell marker CRIg, and performed µPET studies in healthy and CRIg deficient mice to demonstrate that the proposed radiolabeling method does not affect the functional integrity of the protein. Finally, an affibody targeting HER2 (PEP04314) was labeled site-specifically, and the distribution profile of (±)-[18F]AlF(RESCA)-PEP04314 in a rhesus monkey was compared with that of [18F]AlF(NOTA)-PEP04314 using whole-body PET/CT. Conclusion. This generic radiolabeling method has the potential to be a kit-based fluorine-18 labeling strategy, and could have a large impact on PET radiochemical space, potentially enabling the development of many new fluorine-18 labeled protein-based radiotracers. PMID:28824726

  8. Al(18)F-Labeling Of Heat-Sensitive Biomolecules for Positron Emission Tomography Imaging.

    PubMed

    Cleeren, Frederik; Lecina, Joan; Ahamed, Muneer; Raes, Geert; Devoogdt, Nick; Caveliers, Vicky; McQuade, Paul; Rubins, Daniel J; Li, Wenping; Verbruggen, Alfons; Xavier, Catarina; Bormans, Guy

    2017-01-01

    Positron emission tomography (PET) using radiolabeled biomolecules is a translational molecular imaging technology that is increasingly used in support of drug development. Current methods for radiolabeling biomolecules with fluorine-18 are laborious and require multistep procedures with moderate labeling yields. The Al(18)F-labeling strategy involves chelation in aqueous medium of aluminum mono[(18)F]fluoride ({Al(18)F}(2+)) by a suitable chelator conjugated to a biomolecule. However, the need for elevated temperatures (100-120 °C) required for the chelation reaction limits its widespread use. Therefore, we designed a new restrained complexing agent (RESCA) for application of the AlF strategy at room temperature. Methods. The new chelator RESCA was conjugated to three relevant biologicals and the constructs were labeled with {Al(18)F}(2+) to evaluate the generic applicability of the one-step Al(18)F-RESCA-method. Results. We successfully labeled human serum albumin with excellent radiochemical yields in less than 30 minutes and confirmed in vivo stability of the Al(18)F-labeled protein in rats. In addition, we efficiently labeled nanobodies targeting the Kupffer cell marker CRIg, and performed µPET studies in healthy and CRIg deficient mice to demonstrate that the proposed radiolabeling method does not affect the functional integrity of the protein. Finally, an affibody targeting HER2 (PEP04314) was labeled site-specifically, and the distribution profile of (±)-[(18)F]AlF(RESCA)-PEP04314 in a rhesus monkey was compared with that of [(18)F]AlF(NOTA)-PEP04314 using whole-body PET/CT. Conclusion. This generic radiolabeling method has the potential to be a kit-based fluorine-18 labeling strategy, and could have a large impact on PET radiochemical space, potentially enabling the development of many new fluorine-18 labeled protein-based radiotracers.

  9. Fluoride antireflection coatings for deep ultraviolet optics deposited by ion-beam sputtering.

    PubMed

    Yoshida, Toshiya; Nishimoto, Keiji; Sekine, Keiichi; Etoh, Kazuyuki

    2006-03-01

    Optically high quality coatings of fluoride materials are required in deep ultraviolet (DUV) lithography. We have applied ion-beam sputtering (IBS) to obtain fluoride films with smooth surfaces. The extinction coefficients were of the order of 10(-4) at the wavelength of 193 nm due to the reduction of their absorption loss. The transmittance of the MgF2/GdF3 antireflection coating was as high as 99.7% at the wavelength of 193 nm. The surfaces of the IBS deposited films were so smooth that the surface roughness of the A1F3/GdF3 film was comparable with that of the CaF2 substrate. The MgF2/GdF3 coating fulfilled the temperature and humidity requirements of military specification. Thus, the IBS deposited fluoride films are promising candidate for use in the DUV lithography optics.

  10. Oxidative aliphatic C-H fluorination with fluoride ion catalyzed by a manganese porphyrin.

    PubMed

    Liu, Wei; Huang, Xiongyi; Cheng, Mu-Jeng; Nielsen, Robert J; Goddard, William A; Groves, John T

    2012-09-14

    Despite the growing importance of fluorinated organic compounds in drug development, there are no direct protocols for the fluorination of aliphatic C-H bonds using conveniently handled fluoride salts. We have discovered that a manganese porphyrin complex catalyzes alkyl fluorination by fluoride ion under mild conditions in conjunction with stoichiometric oxidation by iodosylbenzene. Simple alkanes, terpenoids, and even steroids were selectively fluorinated at otherwise inaccessible sites in 50 to 60% yield. Decalin was fluorinated predominantly at the C2 and C3 methylene positions. Bornyl acetate was converted to exo-5-fluoro-bornyl acetate, and 5α-androstan-17-one was fluorinated selectively in the A ring. Mechanistic analysis suggests that the regioselectivity for C-H bond cleavage is directed by an oxomanganese(V) catalytic intermediate followed by F delivery via an unusual manganese(IV) fluoride that has been isolated and structurally characterized.

  11. Oxidative aliphatic C-H fluorination with manganese catalysts and fluoride ion.

    PubMed

    Liu, Wei; Huang, Xiongyi; Groves, John T

    2013-12-01

    Fluorination is a reaction that is useful in improving the chemical stability and changing the binding affinity of biologically active compounds. The protocol described here can be used to replace aliphatic, C(sp(3))-H hydrogen in small molecules with fluorine. Notably, isolated methylene groups and unactivated benzylic sites are accessible. The method uses readily available manganese porphyrin and manganese salen catalysts and various fluoride ion reagents, including silver fluoride (AgF), tetrabutylammonium fluoride and triethylamine trihydrofluoride (TREAT·HF), as the source of fluorine. Typically, the reactions afford 50-70% yield of mono-fluorinated products in one step. Two representative examples, the fragrance component celestolide and the nonsteroidal anti-inflammatory drug ibuprofen, are described; they produced useful isolated quantities (250-300 mg, ~50% yield) of fluorinated material over periods of 1-8 h. The procedures are performed in a typical fume hood using ordinary laboratory glassware. No special precautions to rigorously exclude water are required.

  12. Ion-chromatographic determination of chloride and fluoride in electrolyte from the halogen tin-plating process.

    PubMed

    Korth, W; Ellis, J

    1984-06-01

    A simple and rapid procedure is proposed for the determination of chloride and free fluoride in tin electroplating fluid. Suppressor-column ion-chromatography is used after oxidation of hexafluorostannate(II) to hexafluorostannate(IV) with hydrogen peroxide. Concurrent determination of tin(II) and total tin then allows calculation of the concentrations of fluoride, hexafluorostannate(II) and hexafluorostannate(IV).

  13. Ab initio calculations on the positive ions of the alkaline-earth oxides, fluorides, and hydroxides

    NASA Technical Reports Server (NTRS)

    Partridge, H.; Langhoff, S. R.; Bauschlicher, C. W., Jr.

    1986-01-01

    Theoretical dissociation energies are presented for the alkaline-earth fluoride, hydroxide, and oxide positive ions that are considered to be accurate to 0.1-0.2 eV. The r(e) for the positive ions are found to be consistently shorter than the corresponding neutrals by 0.07 + or -0.02 A. The bonding in the ground states is demonstrated to be of predominantly M + 2 X - character. The a 3 Pi and A 1 Pi are found to lie considerably above the X 1 Sigma + ground states of the alkaline-earth fluoride and hydroxide positive ions. The overall agreement of the theoretical ionization potentials with the available experimental appearance potentials is satisfactory; these values should represent the most accurate and consistent set available.

  14. Ab initio calculations on the positive ions of the alkaline-earth oxides, fluorides, and hydroxides

    NASA Technical Reports Server (NTRS)

    Partridge, H.; Langhoff, S. R.; Bauschlicher, C. W., Jr.

    1986-01-01

    Theoretical dissociation energies are presented for the alkaline-earth fluoride, hydroxide, and oxide positive ions that are considered to be accurate to 0.1-0.2 eV. The r(e) for the positive ions are found to be consistently shorter than the corresponding neutrals by 0.07 + or -0.02 A. The bonding in the ground states is demonstrated to be of predominantly M + 2 X - character. The a 3 Pi and A 1 Pi are found to lie considerably above the X 1 Sigma + ground states of the alkaline-earth fluoride and hydroxide positive ions. The overall agreement of the theoretical ionization potentials with the available experimental appearance potentials is satisfactory; these values should represent the most accurate and consistent set available.

  15. The half-life of 18F.

    PubMed

    García-Toraño, Eduardo; Medina, Virginia Peyrés; Ibarra, Miguel Roteta

    2010-01-01

    The half-life of the positron-emitter (18)F has been measured by following the decay rate with three systems: ionization chambers, Ge detectors and coincidence with fast scintillators. The decay rate was measured for periods of time up to 9 half-lives. The combination of the results obtained with the three measuring systems gives a value of T(1/2)=1.82871 (18)h, in good agreement with recommended data and with an estimated uncertainty lower than any other previously reported value. Copyright 2009 Elsevier Ltd. All rights reserved.

  16. A comparison of (/sup 18/F)spiroperidol, (/sup 18/F)benperidol and (/sup 18/F) haloperidol kinetics in baboon brain

    SciTech Connect

    Arnett, C.D.; Shiue, C.Y.; Wolf, A.P.; Fowler, J.S.; Logan, J.

    1984-01-01

    Neuroleptic receptor ligands, spiroperidol, benperidol and haloperidol were labeled with fluorine-18 by a nucleophilic aromatic substitution reaction of p-nitrobenzo-nitrile with /sup 18/F/sup -/ to produce p-(/sup 18/F)fluorobenzonitrile which was converted to p-(/sup 18/F)fluoro-y-chlorobutyrophenone and then alkylated with the appropriate amine to give (/sup 18/F)spiroperidol ((/sup 18/F)SP), (/sup 18/F)benperidol ((/sup 18/F)BEN), or (/sup 18/F)haloperidol ((/sup 18/F)HAL). Specific activity ranged from 3 to 6 Ci/..mu..mol. Anesthetized baboons were injected with 6-17 mCi of (/sup 18/F)-labeled tracer. Kinetic curves (striatum and cerebellum) were obtained from PETT scans up to 4 hr with each drug; (/sup 18/F)SP was studied to 8 hr. (/sup 18/F)SP and (/sup 18/F)BEN exhibited similar kinetics in striatum, with radioactivity concentration plateauing by 30 min after injection and remaining constant for the remainder of the study. These two compounds cleared rapidly from the cerebellum. (/sup 18/F)HAL showed a much different kinetic pattern in the striatum. Although it reached a higher striatal concentration (approx. =0.07% per ml vs. approx. = 0.02% per ml for (/sup 18/F)SP or (/sup 18/F)BEN), a peak occurred at 30 min after injection, followed by a decline almost as rapid as that in the cerebellum. Plasma analyses for (/sup 18/F)SP showed > 90% unchanged drug up to 5 min and approx. = 30% metabolites at 20 min after injection. Pretreatment with (+)-butaclamol abolished the selective distribution of (/sup 18/F)SP to the striatum in the four animals studied. Both (/sup 18/F)SP and (/sup 18/F)BEN may be suitable for PETT studies of neuroleptic receptors, but the in vivo kinetics of these compounds are markedly different from their in vitro receptor binding kinetics.

  17. Comparison of three dimeric 18F-AlF-NOTA-RGD tracers.

    PubMed

    Guo, Jinxia; Lang, Lixin; Hu, Shuo; Guo, Ning; Zhu, Lei; Sun, Zhongchan; Ma, Ying; Kiesewetter, Dale O; Niu, Gang; Xie, Qingguo; Chen, Xiaoyuan

    2014-04-01

    RGD peptide-based radiotracers are well established as integrin αvβ3 imaging probes to evaluate tumor angiogenesis or tissue remodeling after ischemia or infarction. In order to optimize the labeling process and pharmacokinetics of the imaging probes, we synthesized three dimeric RGD peptides with or without PEGylation and performed in vivo screening. Radiolabeling was achieved through the reaction of F-18 aluminum-fluoride complex with the cyclic chelator, 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA). Three imaging probes were synthesized as (18)F-AlF-NOTA-E[c(RGDfK)]2, (18)F-AlF-NOTA-PEG4-E[c(RGDfK)]2, and (18)F-AlF-NOTA-E[PEG4-c(RGDfk)]2. The receptor binding affinity was determined by competitive cell binding assay, and the stability was evaluated by mouse serum incubation. Tumor uptake and whole body distribution of the three tracers were compared through direct tissue sampling and PET quantification of U87MG tumor-bearing mice. All three compounds remained intact after 120 min incubation with mouse serum. They all had a rapid and relatively high tracer uptake in U87MG tumors with good target-to-background ratios. Compared with the other two tracers, (18)F-AlF-NOTA-E[PEG4-c(RGDfk)]2 had the highest tumor uptake and the lowest accumulation in the liver. The integrin receptor specificity was confirmed by co-injection of unlabeled dimeric RGD peptide. The rapid one-step radiolabeling strategy by the complexation of (18)F-aluminum fluoride with NOTA-peptide conjugates was successfully applied to synthesize three dimeric RGD peptides. Among the three probes developed, (18)F-AlF-NOTA-E[PEG4-c(RGDfk)]2 with relatively low liver uptake and high tumor accumulation appears to be a promising candidate for further translational research.

  18. Influence of Fluoride Ion on the Performance of Pb-Ag Anode During Long-Term Galvanostatic Electrolysis

    NASA Astrophysics Data System (ADS)

    Zhong, Xiaocong; Yu, Xiaoying; Jiang, Liangxing; Lv, Xiaojun; Liu, Fangyang; Lai, Yanqing; Li, Jie

    2015-09-01

    Anodic potential, morphology and phase composition of the anodic layer, corrosion morphology of the metallic substrate, and oxygen evolution behavior of Pb-Ag anode in H2SO4 solution without/with fluoride ion were investigated and compared. The results showed that the presence of fluoride ions contributed to a smoother anodic layer with lower PbO2 concentration, which resulted in lower double layer capacity and higher charge transfer resistance for the oxygen evolution reaction. Consequently, the Pb-Ag anode showed a higher anodic potential (about 35 mV) in the fluoride-containing electrolyte. In addition, the fluoride ions accelerated the detachment of loose flakes on the anodic layer. It was demonstrated that the anodic layer formed in the fluoride-containing H2SO4 solution was thinner. Furthermore, fluoride ions aggravated the corrosion of the metallic substrate at interdendritic boundary regions. Hence, the presence of fluoride ions is detrimental to oxygen evolution reactivity and increases the corrosion of the Pb-Ag anode, which may further increase the energy consumption and capital cost of zinc plants.

  19. Electrodeposited apatite coating for solid-phase microextraction and sensitive indirect voltammetric determination of fluoride ions.

    PubMed

    Mao, Yuehong; Chen, Yufei; Chu, Lin; Zhang, Xiaoli

    2013-10-15

    Electrodeposition was used to prepare a new solid phase microextraction (SPME) coatings. Two apatite SPME coatings, dicalcium phosphate dihydrate (DCPD or brushite) and hydroxyapatite (HAP) were validly and homogeneously one-step electrodeposited on glassy carbon electrode (GCE) under different conditions. The coatings were characterized by XRD, FTIR, SEM, CV and EIS. The apatite SPME coatings showed excellent and selective adsorbability to fluoride ions. A novel indirect voltammetric strategy for sensitive detection of fluoride was proposed using K3Fe(CN)6 as indicating probe. The detection principle of fluoride ions was based on the increment of steric hindrance after fluoride adsorption, which resulting in the decrease of the amperometric signal to Fe(CN)6(3-). The liner ranges were 0.5-20.0 μmol/L for n-DCPD/GCE with the limit of detection of 0.14 μmol/L and 0.1-50.0 μmol/L for n-HAP/GCE with the limit of detection of 0.069 μmol/L, respectively. The developed method was applied to the analysis of water samples (lake, spring and tap water) and the recovery values were found to be in the range of 90-106%. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Synergistic effect of sodium ions and fluoride ions on synthesis of pure-phase TiO2(B) nanorings

    NASA Astrophysics Data System (ADS)

    Yan, Wenwen; Zou, Yu; Zhou, Han; Wang, Lili; Meng, Xiangfu

    2017-06-01

    TiO2(B) has received growing interest as negative electrode materials for Li-ion batteries in recent years. However, its metastability is an intrinsic obstacle for obtaining highly pure-phase TiO2(B). In this study, we reported the synthesis of pure-phase TiO2(B) nanorings with high crystallinity via one-pot hydrothermal method in the presence of sodium fluoride (NaF) solution. The as-prepared TiO2(B) nanorings were systematically characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS). The TiO2(B) nanorings had an outer diameter of about 400 nm and inner diameter of about 150 nm. Sodium fluoride was used as phase and morphology control agent. The growth mechanism revealed that sodium ions (Na+) and fluoride ions (F-) had a synergistic effect on the synthesis of pure-phase TiO2(B) nanorings. The morphologies and crystalline phases were easily tailored by tuning the concentration of NaF. The effect of hydrothermal condition on growth of TiO2(B) nanorings was investigated in detail. The as-prepared TiO2(B) nanorings displayed high performance as negative electrode materials in Li-ion batteries.

  1. Compartmental model of 18F-choline

    NASA Astrophysics Data System (ADS)

    Janzen, T.; Tavola, F.; Giussani, A.; Cantone, M. C.; Uusijärvi, H.; Mattsson, S.; Zankl, M.; Petoussi-Henß, N.; Hoeschen, C.

    2010-03-01

    The MADEIRA Project (Minimizing Activity and Dose with Enhanced Image quality by Radiopharmaceutical Administrations), aims to improve the efficacy and safety of 3D functional imaging by optimizing, among others, the knowledge of the temporal variation of the radiopharmaceuticals' uptake in and clearance from tumor and healthy tissues. With the help of compartmental modeling it is intended to optimize the time schedule for data collection and improve the evaluation of the organ doses to the patients. Administration of 18F-choline to screen for recurrence or the occurrence of metastases in prostate cancer patients is one of the diagnostic applications under consideration in the frame of the project. PET and CT images have been acquired up to four hours after injection of 18F-choline. Additionally blood and urine samples have been collected and measured in a gamma counter. The radioactivity concentration in different organs and data of plasma clearance and elimination into urine were used to set-up a compartmental model of the biokinetics of the radiopharmaceutical. It features a central compartment (blood) exchanging with organs. The structure describes explicitly liver, kidneys, spleen, plasma and bladder as separate units with a forcing function approach. The model is presented together with an evaluation of the individual and population kinetic parameters, and a revised time schedule for data collection is proposed. This optimized time schedule will be validated in a further set of patient studies.

  2. Compact non-rock-salt structures in sodium fluoride cluster ions at specific sizes revealed by ion mobility mass spectrometry.

    PubMed

    Ohshimo, Keijiro; Takahashi, Tohru; Moriyama, Ryoichi; Misaizu, Fuminori

    2014-10-30

    Structures of small sodium fluoride cluster cations, Na(n)F(n-1)(+), have been determined for n = 5-23 by ion mobility mass spectrometry. In the mass spectrum of Na(n)F(n-1)(+) cluster ions measured after collisions in the ion-drift cell, cuboid ions with near-regular hexahedron such as n = 14 (3 × 3 × 3), 23 (3 × 3 × 5), 38 (3 × 5 × 5), 63 (5 × 5 × 5), and 88 (5 × 5 × 7) were predominantly observed as magic numbers. By comparison of the collision cross sections obtained from the ion mobility measurements with theoretical ones, we have experimentally shown that the ions of n = 7 and 10 have stable non-rock-salt type structures in which one sodium atom is encapsulated into the sodium fluoride cuboid lattice. The collision cross sections of n = 12 and 13 are almost equal to that of the n = 14 cuboid. A similar feature was also observed in collision cross sections of n = 21 and 22, which are equal to that of the n = 23 cuboid. These features indicate that the cluster ions of n = 12, 13, 21, and 22 have near-cuboid structures with some surface defects.

  3. Automated Synthesis of 18F Analogue of Paclitaxel (PAC): [18F]Paclitaxel (FPAC)

    PubMed Central

    Kalen, Joseph D.; Hirsch, Jerry I.; Kurdziel, Karen A.; Eckelman, William C.; Kiesewetter, Dale O.

    2007-01-01

    A positron-emitting paclitaxel (PAC) derivative could allow in-vivo measurement of multidrug resistance in tumors and, therefore, predict a potential chemotherapeutic benefit to patients. [18F]Paclitaxel was produced using a 2-reaction vessel automated synthesizer followed by HPLC purification. Optimized reaction conditions resulted in radiochemical yields of 21.2 ± 9.6% at end of bombardment, radiochemical purity > 99%, and specific activity of 159 ± 43 GBq/μmol. [18F]Paclitaxel activities of 1.33 ± 0.729 GBq (n=7) were obtained in sterile, pyrogen-free solution for IV administration. PMID:17161952

  4. Capillary electrophoresis with contactless conductivity detection for the quantification of fluoride in lithium ion battery electrolytes and in ionic liquids-A comparison to the results gained with a fluoride ion-selective electrode.

    PubMed

    Pyschik, Marcelina; Klein-Hitpaß, Marcel; Girod, Sabrina; Winter, Martin; Nowak, Sascha

    2017-02-01

    In this study, an optimized method using capillary electrophoresis (CE) with a direct contactless conductivity detector (C(4) D) for a new application field is presented for the quantification of fluoride in common used lithium ion battery (LIB) electrolyte using LiPF6 in organic carbonate solvents and in ionic liquids (ILs) after contacted to Li metal. The method development for finding the right buffer and the suitable CE conditions for the quantification of fluoride was investigated. The results of the concentration of fluoride in different LIB electrolyte samples were compared to the results from the ion-selective electrode (ISE). The relative standard deviations (RSDs) and recovery rates for fluoride were obtained with a very high accuracy in both methods. The results of the fluoride concentration in the LIB electrolytes were in very good agreement for both methods. In addition, the limit of detection (LOD) and limit of quantification (LOQ) values were determined for the CE method. The CE method has been applied also for the quantification of fluoride in ILs. In the fresh IL sample, the concentration of fluoride was under the LOD. Another sample of the IL mixed with Li metal has been investigated as well. It was possible to quantify the fluoride concentration in this sample. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Effect of a Static Magnetic Fields and Fluoride Ions on the Antioxidant Defense System of Mice Fibroblasts

    PubMed Central

    Kurzeja, Ewa; Synowiec-Wojtarowicz, Agnieszka; Stec, Małgorzata; Glinka, Marek; Gawron, Stanisław; Pawłowska-Góral, Katarzyna

    2013-01-01

    The results of studies on the biological influence of magnetic fields are controversial and do not provide clear answers regarding their impact on cell functioning. Fluoride compounds are substances that influence free radical processes, which occur when the reactive forms of oxygen are present. It is not known whether static magnetic fields (SMF) cause any changes in fluoride assimilation or activity. Therefore, the aim of this work was to determine the potential relationship between magnetic field exposure to, and the antioxidant system of, fibroblasts cultured with fluoride ions. Three chambers with static magnetic fields of different intensities (0.4, 0.6, and 0.7 T) were used in this work. Fluoride ions were added at a concentration of 0.12 mM, which did not cause the precipitation of calcium or magnesium. The results of this study show that static magnetic fields reduce the oxidative stress caused by fluoride ions and normalize the activities of antioxidant enzymes, including superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT). Static magnetic fields modify the energy state of fibroblasts, causing an increase in the ATP concentration and a decrease in the MDA concentration. These results suggest that exposure to fluoride and an SMF improves the tolerance of cells to the oxidative stress induced by fluoride ions. PMID:23873295

  6. Effect of a static magnetic fields and fluoride ions on the antioxidant defense system of mice fibroblasts.

    PubMed

    Kurzeja, Ewa; Synowiec-Wojtarowicz, Agnieszka; Stec, Małgorzata; Glinka, Marek; Gawron, Stanisław; Pawłowska-Góral, Katarzyna

    2013-07-18

    The results of studies on the biological influence of magnetic fields are controversial and do not provide clear answers regarding their impact on cell functioning. Fluoride compounds are substances that influence free radical processes, which occur when the reactive forms of oxygen are present. It is not known whether static magnetic fields (SMF) cause any changes in fluoride assimilation or activity. Therefore, the aim of this work was to determine the potential relationship between magnetic field exposure to, and the antioxidant system of, fibroblasts cultured with fluoride ions. Three chambers with static magnetic fields of different intensities (0.4, 0.6, and 0.7 T) were used in this work. Fluoride ions were added at a concentration of 0.12 mM, which did not cause the precipitation of calcium or magnesium. The results of this study show that static magnetic fields reduce the oxidative stress caused by fluoride ions and normalize the activities of antioxidant enzymes, including superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT). Static magnetic fields modify the energy state of fibroblasts, causing an increase in the ATP concentration and a decrease in the MDA concentration. These results suggest that exposure to fluoride and an SMF improves the tolerance of cells to the oxidative stress induced by fluoride ions.

  7. PRECIPITATION OF ZIRCONIUM AND FLUORIDE IONS FROM SOLUTIONS

    DOEpatents

    Newby, B.J.

    1963-06-11

    A process is given for removing zirconium and fluorine ions from aqueous solutions also containing uranium(VI). The precipitation is carried out with sodium formate, and the uranium remains in solution. (AEC)

  8. Microwave-Assisted Radiosynthesis of [18F]Fluorinated Fatty Acid Analogs

    PubMed Central

    Belanger, Anthony P.; Pandey, Mukesh K.; DeGrado, Timothy R.

    2010-01-01

    Microwave reactors remain largely underutilized in the field of PET chemistry. This is particularly unfortunate since microwave synthesis elegantly addresses two of the most critical issues of PET radiochemistry with short-lived radionuclides: reaction rate and side-product formation. In this study we investigate the efficiency of synthesis of terminally [18F]fluorinated fatty acid analogs using a commercial microwave reactor in comparison with conventional heating. Methods The labeling precursors were methyl esters of terminally substituted alkyl bromides and iodides. Duration and temperatures of the [18F]fluorination reaction were varied. Chemical and radiochemical purities, and radiochemical yields were investigated for conventional (CH) and microwave-assisted (MW) radiosyntheses. Results The results demonstrate that microwave heating enhanced [18F]fluoride incorporation to >95% (up to 55% improvement), while reducing reaction times to 2 min (~10-fold reduction) or temperatures to 55–60°C (20°C reduction). Overall decay-corrected radiochemical yields of purified [18F]fluoro fatty acids were higher (MW=49.0 ± 4.5%, CH=23.6 ± 3.5%, p<0.05) with microwave heating and side-products were notably fewer. Conclusion For routine synthesis of [18F]fluoro fatty acid analogs, microwave heating is faster, milder, cleaner, less variable and higher yielding than conventional heating and therefore the preferred reaction method. PMID:21492792

  9. The influence of fluoride ions on the equilibrium between titanium ions and titanium metal in fused alkali chloride melts.

    PubMed

    Song, Jianxun; Wang, Qiuyu; Wu, Jinyu; Jiao, Shuqiang; Zhu, Hongmin

    2016-08-15

    KF is employed as a source of fluoride ions added to the melt to disclose the influence of fluoride on the disproportionation reactions of titanium ions, 3Ti(2+) = 2Ti(3+) + Ti, and 4Ti(3+) = 3Ti(4+) + Ti. The results reveal that the equilibrium transferred to the right direction for the first reaction and the apparent equilibrium constant increased sharply, mainly because of the formation of coordination compounds: TiFi(3-i). The accurate values of the equilibrium constants referring to the formation reactions of Ti(3+) + iF(-) = TiFi(3-i) (i = 1-6) in NaCl-KCl melt at 1023 K were evaluated with a best fit least squares method. It is also revealed that the stable states of the coordination compounds are TiF(2+), TiF2(+), TiF4(-) and TiF6(3-). Moreover, the Gibbs free energies for complex formation were estimated. Ti(2+) was undetectable when the concentration of fluoride ion was high enough. The equilibrium constant for the formation reaction, Ti(4-) + 6F(-) = TiF6(2-), was evaluated. The equilibrium constant, Kc2, for the disproportionation reaction 4Ti(3+) = 3Ti(4+) + Ti, in chloride melt was determined as 0.015.

  10. Effect of methoxy group position on biological properties of (18)F-labeled benzyl triphenylphosphonium cations.

    PubMed

    Chen, Shuting; Zhao, Zuoquan; Zhang, Ying; Fang, Wei; Lu, Jie; Zhang, Xianzhong

    2017-06-01

    (18)F-labeled phosphonium cations targeting mitochondrial membrane potential would be promising for positron emission tomography (PET) myocardial perfusion imaging (MPI). The purpose of this study was to examine the influence of additional methoxy group and its different positions on myocardium uptake and pharmacokinetics properties of (18)F-labeled benzyl triphenylphosphonium cations. In this study, three novel (18)F-labeled phosphonium cations, [(18)F]4-(fluoromethyl)benzyltris(4-methoxyphenyl) phosphonium cation (1b), [(18)F]4-(fluoromethyl)benzyltris(2-methoxyphenyl) phosphonium cation (2b) and [(18)F]4-(fluoromethyl)benzyltris(3-methoxyphenyl) phosphonium cation (3b), were efficiently prepared by a One-Pot method starting from the substitution of non-carried-added fluoride-18. Radiotracers were purified by HPLC. Physicochemical properties, in vitro cell uptake assay, in vivo mice biodistribution and rat micro-PET imaging were investigated. Results suggested that the position of methoxy group exhibited significant effect on the biological properties of (18)F-labeled benzyl triphenylphosphonium cations. The addition of methoxy group on orth- or meta-position of the radiotracers accelerated the radioactivity clearance from liver. The para-radiotracer had the highest uptake in the heart and other non-targeting organs. According to the biodistribution data, 2b (ortho-) displayed the fastest liver clearance and highest heart-to-background ratios. And its rat micro-PET images at 60min post-injection revealed a good visualization of heart and favorable heart-to-background contrast. Nevertheless, 2b exhibited a lower initial liver uptake and quicker liver clearance compared with (99m)Tc-sestamibi. The ortho- compound (2b) displayed the most favorable biological properties as a potential MPI agent to acquire high contrast images early after injection. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. A Practical, Automated Synthesis of meta-[18F]Fluorobenzylguanidine for Clinical Use

    PubMed Central

    Hu, Bao; Vāvere, Amy L.; Neumann, Kiel D.; Shulkin, Barry L.; DiMagno, Stephen G.; Snyder, Scott E.

    2015-01-01

    Many neuroendocrine tumors, such as neuroblastoma (NB), arise from neural crest cells of the sympathetic nervous system. This nerve-like phenotype has been exploited for functional imaging using radioactive probes originally designed for neuronal and adrenal medullary applications. NB imaging with meta-[123I]iodobenzylguanidine ([123I]MIBG) is limited by the emissions of 123I, which lead to poor image resolution and challenges in quantification of its accumulation in tumors. Meta-[18F]Fluorobenzylguanidine ([18F]MFBG) is a promising alternative to [123I]MIBG that could change the standard of practice for imaging neuroendocrine tumors, but interest in this PET radiotracer has suffered due to its complex and inefficient radiosynthesis. Here we report a two-step, automated method for the routine production of [18F]MFBG by thermolysis of a diaryliodonium fluoride and subsequent acid deprotection. The synthesis was adapted for use on a commercially available synthesizer for routine production. Full characterization of [18F]MFBG produced by this route demonstrated the tracer’s suitability for human use. [18F]MFBG was prepared in almost three-fold higher yield than previously reported (31% corrected to end of bombardment, n = 9) in a synthesis time of 56 minutes with > 99.9% radiochemical purity. Other than pH adjustment and dilution of the final product, no reformulation was necessary after purification. This method permits the automated production of multidose batches of clinical grade [18F]MFBG. Moreover, if ongoing clinical imaging trials of [18F]MFBG are successful, this methodology is suitable for rapid commercialization and can be easily adapted for use on most commercial automated radiosynthesis equipment. PMID:26313342

  12. Effect of grinding and fluoride-gel exposure on strength of ion-exchanged porcelain.

    PubMed

    Anusavice, K J; Hojjatie, B; Chang, T C

    1994-08-01

    Strengthening of dental porcelain through a diffusion heat treatment at 450 degrees C of a potassium-enriched, ion-exchange surface coating has been demonstrated in several recent studies. However, little attention has been focused on the potential strength reduction of these materials when the treated surfaces are ground or etched under clinically simulated conditions. The objective of this study was to test the hypothesis that partial removal of the surface layers of ion-exchanged porcelains by grinding or exposure to acidulated fluoride gel will significantly reduce their flexure strength. Nine groups of body porcelain disks were ion-exchanged at 450 degrees C for 30 min. One of these groups was subjected to ion exchange and no further surface treatment. Eight specimen groups were subjected to the following procedures after ion exchange: grinding to depths of 50 microns, 100 microns, 150 microns, 200 microns, and 250 microns, and exposure to acidulated fluoride for 30 min, 60 min, and 300 min. A tenth group (FC) was fired at 960 degrees C and fast-cooled in air, but the disks were not subjected to the ion-exchange treatment. Surface stress was calculated from measured values of cracks induced in the treated surfaces. Fluoride exposure for up to 60 min resulted in a significant decrease in surface compression (P < or = 0.05), although this treatment had no effect on strength. Grinding to a depth of from 100 microns to 250 microns caused a significant decrease in strength, while removal of a 50-microns layer caused no significant change (P > 0.05).

  13. Gas-phase energetics of thorium fluorides and their ions.

    PubMed

    Irikura, Karl K

    2013-02-14

    Gas-phase thermochemistry for neutral ThF(n) and cations ThF(n)(+) (n = 1-4) is obtained from large-basis CCSD(T) calculations, with a small-core pseudopotential on thorium. Electronic partition functions are computed with the help of relativistic MRCI calculations. Geometries, vibrational spectra, electronic fine structure, and ion appearance energies are tabulated. These results support the experimental results by Lau, Brittain, and Hildenbrand for the neutral species, except for ThF. The ion thermochemistry is presented here for the first time.

  14. An estimation of safe concentrations of fluoride ion for rainbow trout and brown trout

    SciTech Connect

    Camargo, J.A.

    1995-12-31

    Safe concentrations of fluoride ion (F-) for two trout species, Oncorhynchus mykiss Walbaum and Salmo trutta L., were estimated from short-term toxicity bioassays (maximum exposure time of 192 hours) using the multifactor probit analysis (MPA) software on lethal data. The MPA software solves the concentration-time-response equation simultaneously via the iterative reweighed least squares technique (multiple linear regression). A safe concentration (SC) refers to the concentration of toxic substance that can exist in a laboratory environment for an extended exposure time (infinite hours) causing mortality at 0.01% population of test species. Toxicity bioassays were conducted in soft water (average hardness value of 21.8 mg CaCO{sub 3}/L). Test fluoride solutions were made from sodium fluoride (NaF). There was a differential response to fluoride toxicity between test species, O. mykiss appearing to be a more sensitive species. SC values (mg F-/L) and their 95% confidence limits were 5.14 (3.10--7.53) for O. mykiss and 7.49 (4.42--10.96) for S. trutta. These SCs are higher than safe concentrations proposed for freshwater invertebrates. It is concluded that the combination of acute toxicity testing and MPA software may be a valuable methodology in environmental toxicology to estimate accurate safe concentrations of chemical compounds for aquatic organisms. However, this methodology should not be viewed as a perfect alternative to chronic toxicity testing.

  15. Ratiometric fluorescent chemosensor for fluoride ion based on inhibition of excited state intramolecular proton transfer

    NASA Astrophysics Data System (ADS)

    Gupta, Akul Sen; Paul, Kamaldeep; Luxami, Vijay

    2015-03-01

    ESIPT based benzimidazole derivative has been synthesized and investigated their photophysical behavior towards various anions. The probe 2 has been used for selective estimation of F- ions as compared to other anions and signaled the binding event through formation of new absorption band at 360 nm and emission band at 420 nm. The probe 2 showed fluorescence behavior towards fluoride ions through hydrogen bonding interactions and restricted the ESIPT emission at 540 nm from OH to nitrogen of benzimidazole moiety to release its enol emission at 420 nm.

  16. Corrosion behaviour of TiN and ZrN in the environment containing fluoride ions.

    PubMed

    Joska, Ludek; Fojt, Jaroslav; Hradilova, Monika; Hnilica, Frantisek; Cvrcek, Ladislav

    2010-10-01

    Nowadays, a wide range of materials for human implants is used. To reach the required properties of implants, coatings are applied in some cases. This contribution is focused on the corrosion properties of TiN and ZrN layers on cp-titanium (commercially pure titanium) under environment modelling conditions in an oral cavity. Measurements were done in artificial saliva and a physiological solution unbuffered and buffered to a pH value of 4.2 with the addition of fluoride ions up to 4000 ppm. Standard corrosion electrochemical techniques were applied. Both types of layers were stable in both model saliva and physiological solution with non-adjusted pH. The decrease in pH to 4.2 resulted in a minor decrease of corrosion resistance in all cases, but polarization resistance was still in the order of 10(5) Ω cm². An important change in a specimens' behaviour was noticed in the presence of fluoride ions. TiN was stable in the highest concentration of fluorides used. The ZrN layers were destabilized in an environment containing a few hundred ppm of fluoride ions. As for TiN, the decisive factor is the influence of porosity; the corrosion resistance of ZrN is limited. From the corrosion point of view, the application of the TiN-based barrier layers in dental implantology is more advisable than the use of ZrN, provided that the application of a barrier is inevitable.

  17. Colorimetric and fluorimetric response of salicylaldehyde dithiosemicarbazone towards fluoride, cyanide and copper ions: Spectroscopic and TD-DFT studies

    NASA Astrophysics Data System (ADS)

    Harikrishnan, Vengayil K.; Basheer, Sabeel M.; Joseph, Nithin; Sreekanth, Anandaram

    2017-07-01

    The sensing mechanism of salicylaldehyde phenyldithiosemicarbazone (SDTSC) chemosensor has been investigated by spectroscopic and TD-DFT methods. The SDTSC shows colourimetric and spectral changes towards fluoride, cyanide and copper ions. The interaction between SDTSC with fluoride, cyanide and copper ions was examined through their absorption and fluorescence behaviour, and found that SDTSC has more sensing ability towards Cu2 + ion than CN- and F- ions. The 1H NMR titration with SDTSC and F- gives the structural changes in the sensing process. The reversibility of SDTSC was also evaluated and thus it is confirmed as a reusable chemosensor which can be clarified by the ;Read-Erase-Read-Write; logic system. The DFT and TD-DFT calculations give the detailed sensing mechanism of SDTSC towards fluoride ion. The potential energy surface (PES) analysis confirms the excited state electron transfer mechanism.

  18. High-yield, automated radiosynthesis of 2-(1-{6-[(2-[18F]fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene)malononitrile ([18F]FDDNP) ready for animal or human administration.

    PubMed

    Liu, Jie; Kepe, Vladimir; Zabjek, Alenka; Petric, Andrej; Padgett, Henry C; Satyamurthy, Nagichettiar; Barrio, Jorge R

    2007-01-01

    The biomarker 2-(1-{6-[(2-[(18)F]fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene)malononitrile ([(18)F]FDDNP) is used as a positron emission tomography (PET) imaging probe for Alzheimer's disease and other neurodegenerative diseases. A high-yield and fully automated synthesis of [(18)F]FDDNP--along with the synthesis and characterization of non-radioactive FDDNP, a fluorescent probe derived from 2-(1,1-dicyanopropenyl-2)-6-dimethylaminonaphthalene (DDNP)--are reported. Radiofluorination of the tosyloxy precursor 2-{[6-(2,2-dicyano-1-methylvinyl)-2-naphthyl](methyl)amino}ethyl-4-methylbenzenesulfonate (DDNPTs) with K(18)F/Kryptofix 2.2.2. yielded chemically (>99%) and radiochemically (>99%) pure [(18)F]FDDNP in high radiochemical yields (40-60%; n> 120), with specific activities ranging from 4 to 8 Ci/mumol at the end of synthesis (90 minutes). Both remote, semiautomated and automated synthesis procedures are described. Either approach provides a reliable method for production of large quantities (110-170 mCi from 500 mCi of [(18)F]fluoride) of [(18)F]FDDNP allowing for multiple PET experiments in the same day or for distribution of the tracer from a single cyclotron facility to PET imaging centers at various geographical distances.

  19. Synthesis of 6-acrylamido-4-(2-[18F]fluoroanilino)quinazoline: Aprospective irreversible EGFR binding probe

    SciTech Connect

    Vasdev, Neil; Dorff, Peter N.; Gibbs, Andrew R.; Nandanan,Erathodiyil; Reid, Leanne M.; O'Neil, James P.; VanBrocklin, Henry F.

    2004-03-30

    Acrylamido-quinazolines substituted at the 6-position bindirreversibly to the intracellular ATP binding domain of the epidermalgrowth factor receptor (EGFR). A general route was developed forpreparing 6-substituted-4-anilinoquinazolines from [18F]fluoroanilinesfor evaluation as EGFR targeting agents with PET. By a cyclizationreaction, 2-[18F]fluoroaniline was reacted withN'-(2-cyano-4-nitrophenyl)-N,N-dimethylimidoformamide to produce6-nitro-4-(2-[18F]fluoroanilino)quinazoline in 27.5 percentdecay-corrected radiochemical yield. Acid mediated tin chloride reductionof the nitro group was achieved in 5 min (80 percent conversion) andsubsequent acylation with acrylic acid gave6-acrylamido-4-(2-[18F]fluoroanilino)quinazoline in 8.5 percentdecay-corrected radiochemical yield, from starting fluoride, in less than2 hours.

  20. Dentifrice Fluoride

    NASA Astrophysics Data System (ADS)

    Rakita, Philip E.

    2004-05-01

    The effectiveness of the fluoride ion in lowering the incidence of dental caries is a major factor in the field of dental health. Observations and research studies in the first half of the 20th century have lead to the widespread adoption of fluoridated water and the use of inorganic fluoride compounds in oral care products, such as toothpaste and dental rinses. This article provides a brief review of the types of compounds used and the chemistry involved.

  1. A one-step automated synthesis of the dopamine transporter ligand [(18)F]FECNT from the chlorinated precursor.

    PubMed

    Pijarowska-Kruszyna, Justyna; Jaron, Antoni; Kachniarz, Artur; Malkowski, Bogdan; Garnuszek, Piotr; Mikolajczak, Renata

    2016-03-01

    The use of [(18)F]labelled nortropane derivative 2β-carbomethoxy-3β-(4-chlorophenyl)-8-(2-fluoroethyl)-nortropane (FECNT) as a dopamine transporter ligand for PET imaging is dependent on efficient radiosynthesis method. Herein, the automated synthesis of [(18)F]FECNT from its chlorinated precursor in commercially available SynChrom [(18)F] R&D module has been developed. The synthesis unit was readily configured for the one-step synthesis from corresponding chlorinated precursor. The radiolabeling process involved a classical [(18)F]fluoride nucleophilic substitution performed at 110 °C for 12 min and finally HPLC and SPE purification. Crude [(18)F]FECNT was obtained with a radiolabeling yield of 59 ± 12% (n = 5). The average uncorrected amount of [(18)F]FECNT in the final formulated dose was 2.0 ± 0.5 GBq (32 ± 7% overall decay-corrected yields) obtained with radiochemical purity over 99% and specific activity of 55 GBq/µmol. The total duration of the procedure was 80-90 min. An automated radiosynthesis of [(18)F]FECNT with high radiochemical purity may provide a simple and robust method of radiopharmaceutical preparation for routine clinical applications.

  2. Tuning the Colors of the Dark Isomers of Photochromic Boron Compounds with Fluoride Ions: Four-State Color Switching.

    PubMed

    Mellerup, Soren K; Rao, Ying-Li; Amarne, Hazem; Wang, Suning

    2016-09-02

    Combining a three-coordinated boron (BMes2) moiety with a four-coordinated photochromic organoboron unit leads to a series of new diboron compounds that undergo four-state reversible color switching in response to stimuli of light, heat, and fluoride ions. Thus, these hybrid diboron systems allow both convenient color tuning/switching of such photochromic systems, as well as visual fluoride sensing by color or fluorescent emission color change.

  3. [18F]FETO: metabolic considerations.

    PubMed

    Ettlinger, Dagmar E; Wadsak, Wolfgang; Mien, Leonhard-Key; Machek, Michael; Wabnegger, Leila; Rendl, Gundula; Karanikas, Georgios; Viernstein, Helmut; Kletter, Kurt; Dudczak, Robert; Mitterhauser, Markus

    2006-08-01

    11beta-Hydroxylase is a key enzyme in the biosynthesis of adrenocortical steroid hormones and is a suitable target for the imaging of the adrenal cortex. [(11)C]Metomidate (MTO), [(11)C]etomidate (ETO) and desethyl-[(18)F]fluoroethyl-etomidate (FETO) are potent inhibitors of this enzyme and are used for PET imaging of adrenocortical pathologies. The aims of this study were (1) to evaluate and compare the metabolic stability of MTO, ETO and FETO against esterases and (2) to investigate the metabolic pattern of FETO in vivo. In vitro assays were performed using different concentrations of MTO, ETO and FETO with constant concentrations of carboxylesterase. Human in vivo studies were performed with human blood samples drawn from the cubital vein. After sample clean-up, the serum was analysed by HPLC methods. In vitro assays showed Michaelis-Menten constants of 115.1 mumol for FETO, 162.0 mumol for MTO and 168.6 mumol for ETO. Limiting velocities were 1.54 mumol/min (FETO), 1.47 mumol/min (MTO) and 1.35 mumol/min (ETO). This implies insignificantly decreased esterase stability of FETO compared with MTO and ETO. In vivo investigations showed a rapid metabolisation of FETO within the first 10 min (2 min: 91.41%+/-6.44%, n=6; 10 min: 23.78%+/-5.54%, n=4) followed by a smooth decrease in FETO from 20 to 90 min (20 min: 11.23%+/-3.79% n=4; 90 min: 3.68%+/-3.65%, n=4). Recovery rate was 61.43%+/-3.19% (n=12). In vitro experiments demonstrated that FETO stability against esterases is comparable to that of ETO and MTO. The metabolic profile showed that FETO kinetics in humans are fast.

  4. 18F-FDG/18F-FES standardized uptake value ratio determined using PET predicts prognosis in uterine sarcoma

    PubMed Central

    Yamamoto, Makoto; Tsujikawa, Tetsuya; Yamada, Shizuka; Kurokawa, Tetsuji; Shinagawa, Akiko; Chino, Yoko; Mori, Tetsuya; Kiyono, Yasushi; Okazawa, Hidehiko; Yoshida, Yoshio

    2017-01-01

    We investigated whether 16α-[18F]-fluoro-17β-estradiol (18F-FES) and 18F-fluoro-deoxyglucose (FDG) uptake measured using positron emission tomography (PET) predicted prognosis in 18 patients with different histological subtypes of uterine sarcoma. Standardized uptake values (SUVs) and 18F-FDG/18F-FES SUV ratios were determined, and their correlations with progression-free (PFS) and overall survival (OS) were examined. Ten patients died from local recurrence or metastasis, and one more experienced recurrence, during the at least 36-month follow-up period. Patients with higher 18F-FDG SUVs (> 5.5) had worse OS (p = 0.007) and tended toward worse PFS (p = 0.11), while patients with lower 18F-FES SUVs (≤ 1.5) had worse PFS (p = 0.03) and tended toward worse OS (p = 0.19). Patients with 18F-FDG/18F-FES ratios > 2.6 had worse PFS (p = 0.009) and OS (p = 0.005). The 5-year PFS and OS rates were 75% and 88% for patients with lower ratios, but were only 10% and 20% for those with higher ratios. These results suggest that pretreatment tumor 18F-FDG/18F-FES ratio is useful for predicting the prognosis of uterine sarcoma patients. PMID:28186981

  5. Influence of sodium fluoride and caffeine on the concentration of fluoride ions, glucose, and urea in blood serum and activity of protein metabolism enzymes in rat liver.

    PubMed

    Birkner, Ewa; Grucka-Mamczar, Ewa; Zalejska-Fiolka, Jolanta; Chlubek, Dariusz; Kasperczyk, Slawomir; Stawiarska-Pieta, Barbara; Blaszczyk, Urszula

    2006-08-01

    The aim of the study was examining the effect of fluoride ions and caffeine administration on glucose and urea concentration in blood serum and the activity of protein metabolism enzymes and selected enzymes of the urea cycle in rat liver. The study was carried out using 18 male Sprague-Daowley rats (4.5 mo old). Rats were divided into three groups. Group I received distilled water ad libitum. Group II received 4.9 mg F-/kg body mass/d of sodium fluoride in the water, and group III received sodium fluoride (in the above-mentioned dose) and 3 mg/kg body mass/d of caffeine in the water. After 50 d, the rats were anesthetized with thiopental and fluoride ions, glucose, and urea concentration in blood serum were determined. Also determined were the activities of aspartate aminotransferase, alanine aminotransferase glutamate dehydrogenase, ornithine carbamoylotransferase and arginase in liver homogenates. Liver was taken for pathomorphological examinations. The applied doses of F- (4.9 mg/kg body mass/d) and F- + caffeine (4.9 mg F-/kg body mass/d + 3 mg caffeine/kg body mass/d) resulted in a statistically significant increase of fluoride ion concentration in blood serum, a slight increase of the glucose concentration, and no changes in the concentration of urea in blood serum. This might testify to the absence of kidney lesions for the applied concentrations of F-. No change in the functioning of hepatocytes was observed; however, slight disturbances have been noted in the functioning of the liver, connected with the activation of urea cycle, increase of arginase activity, and accumulation of F- in this organ. There was no observed significant influence of caffeine supplementation on the obtained results.

  6. Characterization of Physiologic (18)F FSPG Uptake in Healthy Volunteers.

    PubMed

    Mosci, Camila; Kumar, Meena; Smolarz, Kamilla; Koglin, Norman; Stephens, Andrew W; Schwaiger, Markus; Gambhir, Sanjiv S; Mittra, Erik S

    2016-06-01

    Purpose To evaluate the normal biodistribution and kinetics of (S)-4-(3-[18F]fluoropropyl)-l-glutamic acid ((18)F FSPG) in healthy volunteers and to compare (18)F FSPG mean and maximum standardized uptake values (SUVmean and SUVmax, respectively) with those of (18)F fluorodeoxyglucose (FDG) across a variety of organs. Materials and Methods This protocol was reviewed and approved by all appropriate regulatory authorities. An 8-mCi (±10%) dose of (18)F FSPG was given to five subjects (three women, two men), and seven whole-body positron emission tomography (PET) scans were performed 5, 10, 20, 30, 45, 150, and 240 minutes after injection. Regions of interest were analyzed on the resultant (18)F FSPG images to evaluate the kinetics of this radiotracer. The images obtained 45 minutes after injection were used to measure SUVmean and SUVmax in additional regions of the body. These values were compared with similar values obtained with (18)F FDG PET published previously. Descriptive statistics, including average and standard deviation across the five subjects, were used. (18)F FSPG SUVmean and SUVmax were compared. Results On the (18)F FSPG images obtained 45 minutes after injection, there was only low-grade background activity in the majority of analyzed regions. Prominent activity was seen throughout the pancreas. Clearance of the radiotracer through the kidneys and collection in the bladder also were seen. SUV quantification shows notable differences between (18)F FSPG and (18)F FDG in the pancreas ((18)F FSPG SUVmean, 8.2; (18)F FDG SUVmean, 1.3), stomach ((18)F FSPG SUVmax, 3.6; (18)F FDG SUVmax, 1.6), and brain ((18)F FSPG SUVmean, 0.08; (18)F FDG SUVmean, 7.8). The kinetic data showed rapid clearance of the radiotracer from the blood pool and most organs, except the pancreas. Conclusion (18)F FSPG is a PET radiopharmaceutical characterized by rapid clearance from most healthy tissues, except the pancreas and kidneys. A consistent biodistribution pattern was

  7. Mechanical synthesis and structural properties of the fast fluoride-ion conductor PbSnF4

    NASA Astrophysics Data System (ADS)

    Fujisaki, Fumika; Mori, Kazuhiro; Yonemura, Masao; Ishikawa, Yoshihisa; Kamiyama, Takashi; Otomo, Toshiya; Matsubara, Eiichiro; Fukunaga, Toshiharu

    2017-09-01

    A fluoride-ion conductor, γ-PbSnF4, was synthesized by the mechanical milling. In addition, β-PbSnF4 was obtained by aging the γ-PbSnF4 at 473 K. The electrical conductivity of β-PbSnF4 is relatively higher than that of γ-PbSnF4 at 298 K. The crystal structure analysis of γ- and β-PbSnF4 was carried out using neutron diffraction data. From the obtained occupancies, fluoride ions were located at the Fγ(1) normal site (62%) and Fγ(2) interstitial site (38%) in γ-PbSnF4 and the Fβ(1) normal site (31%), Fβ(2) normal site (25%), and Fβ(3) interstitial site (44%) in β-PbSnF4. In particular, the number of fluoride ions at the F interstitial site increased after the γ-to-β phase transition: 38% at Fγ(2) to 44% at Fβ(3). It is most likely that the ratio of fluoride ions to vacancies (or the effective carrier concentration) was optimized in the ;-Fβ(1)-Fβ(3)-Fβ(3)-Fβ(1)-; conduction pathways of fluoride ions in β-PbSnF4.

  8. Oxidative aliphatic C-H fluorination with manganese catalysts and fluoride ion

    PubMed Central

    Liu, Wei; Huang, Xiongyi; Groves, John T

    2014-01-01

    Fluorination is a reaction that is useful in improving the chemical stability and changing the binding affinity of biologically active compounds. The protocol described here can be used to replace aliphatic, C(sp3)-H hydrogen in small molecules with fluorine. Notably, isolated methylene groups and unactivated benzylic sites are accessible. The method uses readily available manganese porphyrin and manganese salen catalysts and various fluoride ion reagents, including silver fluoride (AgF), tetrabutylammonium fluoride and triethylamine trihydrofluoride (TREAT·HF), as the source of fluorine. Typically, the reactions afford 50–70% yield of mono-fluorinated products in one step. Two representative examples, the fragrance component celestolide and the nonsteroidal anti-inflammatory drug ibuprofen, are described; they produced useful isolated quantities (250–300 mg, ~50% yield) of fluorinated material over periods of 1–8 h. The procedures are performed in a typical fume hood using ordinary laboratory glassware. No special precautions to rigorously exclude water are required. PMID:24177292

  9. Molten fluoride salts incorporation into pristine and ion-modified carbon allotropes and metallic foils

    NASA Astrophysics Data System (ADS)

    Vacík, J.; Hnatowicz, V.; Ĉervená, J.; Mach, R.; Peka, I.

    1999-01-01

    Incorporation of molten fluoride salts into different carbon allotropes (glassy carbon, pyrolytic graphite etc.) and metallic foils (Ni, Ti, etc.), pristine and ion- treated substances, has been studied using non-destructive, depth sensitive nuclear analytical methods—Neutron Depth Profiling (NDP) and Rutherford Backscattering (RBS). Strong interaction between the molten LiF and LiF+KF+NaF salts and the tested materials was found. The results are of great interest for accelerator driven transmutation technology (ADTT) which is a promising way towards effective liquidation of nuclear wastes.

  10. 18F-FET and 18F-FCH uptake in human glioblastoma T98G cell lines

    PubMed Central

    Persico, Marco Giovanni; Buroni, Federica Eleonora; Pasi, Francesca; Aprile, Carlo; Nano, Rosanna; Hodolic, Marina

    2016-01-01

    Abstract Background Despite complex treatment of surgery, radiotherapy and chemotherapy, high grade gliomas often recur. Differentiation between post-treatment changes and recurrence is difficult. 18F-methyl-choline (18F-FCH) is frequently used in staging and detection of recurrent prostate cancer disease as well as some brain tumours; however accumulation in inflammatory tissue limits its specificity. The 18F-ethyl-tyrosine (18F-FET) shows a specific uptake in malignant cells, resulting from increased expression of amino acid transporters or diffusing through the disrupted blood-brain barrier. 18F-FET exhibits lower uptake in machrophages and other inflammatory cells. Aim of this study was to evaluate 18F-FCH and 18F-FET uptake by human glioblastoma T98G cells. Material and methods Human glioblastoma T98G or human dermal fibroblasts cells, seeded at a density to obtain 2 × 105 cells per flask when radioactive tracers were administered, grew adherent to the plastic surface at 37°C in 5% CO2 in complete medium. Equimolar amounts of radiopharmaceuticals were added to cells for different incubation times (20 to 120 minutes) for 18F-FCH and 18F-FET respectively. The cellular radiotracer uptake was determined with a gamma counter. All experiments were carried out in duplicate and repeated three times. The uptake measurements are expressed as the percentage of the administered dose of tracer per 2 × 105 cells. Data (expressed as mean values of % uptake of radiopharmaceuticals) were compared using parametric or non-parametric tests as appropriate. Differences were regarded as statistically significant when p<0.05. Results A significant uptake of 18F-FCH was seen in T98G cells at 60, 90 and 120 minutes. The percentage uptake of 18F-FET in comparison to 18F-FCH was lower by a factor of more than 3, with different kinetic curves.18F-FET showed a more rapid initial uptake up to 40 minutes and 18F-FCH showed a progressive rise reaching a maximum after 90 minutes

  11. Inflammation and infection: imaging properties of 18F-FDG-labeled white blood cells versus 18F-FDG.

    PubMed

    Pellegrino, Daniela; Bonab, Ali A; Dragotakes, Stephen C; Pitman, Justin T; Mariani, Giuliano; Carter, Edward A

    2005-09-01

    (18)F-FDG and (18)F-FDG-labeled white blood cells ((18)F-FDG-WBCs) are valuable radiopharmaceuticals for imaging focal sites of inflammation and infection. In the present study, the imaging properties of both radiotracers were compared in sterile and septic inflammation models. Groups of adult male Sprague-Dawley rats (100-120 g) were injected in the left posterior thigh muscle with saline solution (group 1: controls, n = 15), 0.100 mL of turpentine oil (group 2: sterile inflammation, n = 26), 10(9) viable Escherichia coli bacteria (group 3: E. coli septic inflammation, n = 29), or 10(8) viable Pseudomonas aeruginosa bacteria (group 4: P. aeruginosa septic inflammation, n = 25). Twenty-four hours later, the animals were divided into 2 groups: One received (18)F-FDG intravenously and the other received human white blood cells (WBCs) labeled in vitro with (18)F-FDG injected intravenously. Biodistribution and microPET studies were performed 1 h after radiotracer injection. One hour after injection with cell-associated or free (18)F-FDG, phosphorimaging of abscess and contralateral muscle was performed in specimens collected from animals in groups 1, 2, and 3. The region of interest was selected within the abscess wall and values were converted to kBq/g using a (14)C calibration standard curve. Thin-layer radiochromatography (TLRC) was performed to study the chemical forms of (18)F within the WBCs. Whole-body biodistribution demonstrated a significantly higher uptake ratio of (18)F-FDG-WBCs compared with (18)F-FDG in all sterile and septic inflammation models (t test: sterile, P = 0.048; E. coli, P = 0.040; P. aeruginosa, P = 0.037). microPET imaging confirmed the greater performance of (18)F-FDG-WBCs versus (18)F-FDG in the sterile inflammation model and in both E. coli and P. aeruginosa septic models. Phosphorimaging analysis showed higher (18)F-FDG-WBC uptake than (18)F-FDG in the sterile inflammation and P. aeruginosa septic models and similar tissue uptake in the

  12. Effects of capecitabine treatment on the uptake of thymidine analogs using exploratory PET imaging agents: (18)F-FAU, (18)F-FMAU, and (18)F-FLT.

    PubMed

    McHugh, Christopher I; Lawhorn-Crews, Jawana M; Modi, Dipenkumar; Douglas, Kirk A; Jones, Steven K; Mangner, Thomas J; Collins, Jerry M; Shields, Anthony F

    2016-10-17

    A principal goal for the use of positron emission tomography (PET) in oncology is for real-time evaluation of tumor response to chemotherapy. Given that many contemporary anti-neoplastic agents function by impairing cellular proliferation, it is of interest to develop imaging modalities to monitor these pathways. Here we examined the effect of capecitabine on the uptake of thymidine analogs used with PET: 3'-deoxy-3'-[(18)F]fluorothymidine ((18)F-FLT), 1-(2'-deoxy-2'-[(18)F]fluoro-β-D-arabinofuranosyl) thymidine ((18)F-FMAU), and 1-(2'-deoxy-2'-[(18)F]fluoro-β-D-arabinofuranosyl) uracil ((18)F-FAU) in patients with advanced cancer. Fifteen patients were imaged, five with each imaging agent. Patients had been previously diagnosed with breast, colorectal, gastric, and esophageal cancers and had not received therapy for at least 4 weeks prior to the first scan, and had not been treated with any prior fluoropyrimidines. Subjects were imaged within a week before the start of capecitabine and on the second day of treatment, after the third dose of capecitabine. Tracer uptake was quantified by mean standard uptake value (SUVmean) and using kinetic analysis. Patients imaged with (18)F-FLT showed variable changes in retention and two patients exhibited an increase in SUVmean of 172.3 and 89.9 %, while the other patients had changes ranging from +19.4 to -25.4 %. The average change in (18)F-FMAU retention was 0.2 % (range -24.4 to 23.1) and (18)F-FAU was -10.2 % (range -40.3 to 19.2). Observed changes correlated strongly with SUVmax but not kinetic measurements. This pilot study demonstrates that patients treated with capecitabine can produce a marked increase in (18)F-FLT retention in some patients, which will require further study to determine if this flare is predictive of therapeutic response. (18)F-FAU and (18)F-FMAU showed little change, on average, after treatment.

  13. Determination of Fluoride in Toothpaste Using an Ion-Selective Electrode

    ERIC Educational Resources Information Center

    Light, Truman S.; Cappuccino, Carleton C.

    1975-01-01

    Outlines the theory of chemical potentiometry, describes the experimental procedure for free fluoride determination, and presents sample data of fluoride concentration for various brands of toothpaste. (GS)

  14. Determination of Fluoride in Toothpaste Using an Ion-Selective Electrode

    ERIC Educational Resources Information Center

    Light, Truman S.; Cappuccino, Carleton C.

    1975-01-01

    Outlines the theory of chemical potentiometry, describes the experimental procedure for free fluoride determination, and presents sample data of fluoride concentration for various brands of toothpaste. (GS)

  15. A naphthalene benzimidazole-based chemosensor for the colorimetric and on-off fluorescent detection of fluoride ion

    NASA Astrophysics Data System (ADS)

    Li, Dongmei; Zhong, Zhimin; Zheng, Gengxiu; Tian, Zhongzhen

    2017-10-01

    A novel naphthalene benzimidazole (NBI)-based chemosensor (D2) was developed for fluoride ion (F-) detection. The absorption spectrum of D2 changed dramatically from yellow to blue in the visible region accompanied with a 225 nm red shift of its absorption maximum upon the addition of F- in DMSO. D2 also exhibited a fluorescence turn-off response towards the fluoride ion. The emission intensity of D2 decreased drastically along the increasing F- concentration and the detection limit for F- was as low as 3.2 × 10- 9 mol/L. 1H NMR and HRMS-ESI results indicated that the formation of NBI-O- through the desilylation reaction of F- with NBI-OSi was responsible for the spectral changes. Overall, this kind of NBI-type molecules represent a new type chemosensor for the spectral detection of fluoride ion in solution.

  16. Stabilization of Th{sup 3+} ions into mixed-valence thorium fluoride

    SciTech Connect

    Dubois, Marc; Dieudonne, Belto; Mesbah, Adel; Bonnet, Pierre; El-Ghozzi, Malika; Renaudin, Guillaume; Avignant, Daniel

    2011-01-15

    The unusual oxidation state +3 of the thorium has been stabilized into a lithium containing non-stoichiometric mixed-valence (III/IV) thorium fluorinated phase with formula Li{sub 2+x}Th{sub 12}F{sub 50} (0ions can be divided into two groups and are located either in locked positions or in open channels of the three dimensional framework. The amount of Li{sup +} ions in open channels can be variable, so that the afore mentioned single phase may be considered as an insertion compound. The Li{sup +} insertion is accompanied by the simultaneous reduction of a part of the Th{sup 4+} ions, resulting in a mixed-valence III/IV thorium fluoride. The electrochemical insertion of Li{sup +} ions into the open channels of the host matrix has been carried out at 60 {sup o}C, using an alkylcarbonate PC-LiClO{sub 4} 1 M electrolyte. The Li{sup +} and Th{sup 3+} contents, both in the starting composition and the Li{sup +} inserted ones, were investigated by high resolution solid state {sup 7}Li NMR and EPR, respectively. -- Graphical abstract: Electrochemical insertion of Li{sup +} ions into mixed-valence III/IV thorium fluoride and EPR spectra for the raw and inserted compounds. Display Omitted

  17. cGMP production of the radiopharmaceutical [(18) F]MK-6240 for PET imaging of human neurofibrillary tangles.

    PubMed

    Collier, Thomas Lee; Yokell, Daniel L; Livni, Eli; Rice, Peter A; Celen, Sofie; Serdons, Kim; Neelamegam, Ramesh; Bormans, Guy; Harris, Dawn; Walji, Abbas; Hostetler, Eric D; Bennacef, Idriss; Vasdev, Neil

    2017-05-15

    Fluorine-18-labelled 6-(fluoro)-3-(1H-pyrrolo[2,3-c]pyridin-1-yl)isoquinolin-5-amine ([(18) F]MK-6240) is a novel potent and selective positron emission tomography (PET) radiopharmaceutical for detecting human neurofibrillary tangles, which are made up of aggregated tau protein. Herein, we report the fully automated 2-step radiosynthesis of [(18) F]MK-6240 using a commercially available radiosynthesis module, GE Healthcare TRACERlab FXFN . Nucleophilic fluorination of the 5-diBoc-6-nitro precursor with potassium cryptand [(18) F]fluoride (K[(18) F]/K222 ) was performed by conventional heating, followed by acid deprotection and semipreparative high-performance liquid chromatography under isocratic conditions. The isolated product was diluted with formulation solution and sterile filtered under Current Good Manufacturing Practices, and quality control procedures were established to validate this radiopharmaceutical for human use. At the end of synthesis, 6.3 to 9.3 GBq (170-250 mCi) of [(18) F]MK-6240 was formulated and ready for injection, in an uncorrected radiochemical yield of 7.5% ± 1.9% (relative to starting [(18) F]fluoride) with a specific activity of 222 ± 67 GBq/μmol (6.0 ± 1.8 Ci/μmol) at the end of synthesis (90 minutes; n = 3). [(18) F]MK-6240 was successfully validated for human PET studies meeting all Food and Drug Administration and United States Pharmacopeia requirements for a PET radiopharmaceutical. The present method can be easily adopted for use with other radiofluorination modules for widespread clinical research use. Copyright © 2017 John Wiley & Sons, Ltd.

  18. Electrochemical reactions in fluoride-ion batteries: mechanistic insights from PDF analysis

    DOE PAGES

    Grenier, Antonin; Porras-Gutierrez, Ana-Gabriela; Groult, Henri; ...

    2017-08-14

    Detailed analysis of electrochemical reactions occurring in a rechargeable Fluoride-Ion Battery (FIB) is provided by means of synchrotron X-ray diffraction (XRD) and Pair Distribution Function (PDF) analysis. In this study, a symmetrical cell containing Bi-BiF3 composite electrodes was characterized after three cycles. As for Li conversionbased electrodes, our study confirms that a multi-electron redox process occurs between Bi metal and BiF3. XRD and PDF analyses show that multiple Bi oxyfluoride phases are formed due to the presence of Bi oxide in the initial Bi electrode and/or Bi oxyfluoride in the initial BiF3 electrode. Quantitative PDF analyses suggests that oxygen doesmore » not migrate through the electrolyte and that the fluoride ion is the sole charge transfer anion. Hence, we showed that oxide species are not preventing the electrochemical reactions, opening the path for the study of metal oxyfluoride as active materials for FIBs.« less

  19. A family of fluoride-specific ion channels with dual-topology architecture

    PubMed Central

    Stockbridge, Randy B; Robertson, Janice L; Kolmakova-Partensky, Ludmila; Miller, Christopher

    2013-01-01

    Fluoride ion, ubiquitous in soil, water, and marine environments, is a chronic threat to microorganisms. Many prokaryotes, archea, unicellular eukaryotes, and plants use a recently discovered family of F− exporter proteins to lower cytoplasmic F− levels to counteract the anion’s toxicity. We show here that these ‘Fluc’ proteins, purified and reconstituted in liposomes and planar phospholipid bilayers, form constitutively open anion channels with extreme selectivity for F− over Cl−. The active channel is a dimer of identical or homologous subunits arranged in antiparallel transmembrane orientation. This dual-topology assembly has not previously been seen in ion channels but is known in multidrug transporters of the SMR family, and is suggestive of an evolutionary antecedent of the inverted repeats found within the subunits of many membrane transport proteins. DOI: http://dx.doi.org/10.7554/eLife.01084.001 PMID:23991286

  20. Polyethylene-supported polyvinylidene fluoride-cellulose acetate butyrate blended polymer electrolyte for lithium ion battery

    NASA Astrophysics Data System (ADS)

    Liu, Jiansheng; Li, Weishan; Zuo, Xiaoxi; Liu, Shengqi; Li, Zhao

    2013-03-01

    The polyethylene (PE)-supported polymer membranes based on the blended polyvinylidene fluoride (PVDF) and cellulose acetate butyrate (CAB) are prepared for gel polymer electrolyte (GPE) of lithium ion battery. The performances of the prepared membranes and the resulting GPEs are investigated by scanning electron microscopy, electrochemical impedance spectroscopy, linear potential sweep, and charge-discharge test. The effect of the ratio of PVDF to CAB on the performance of the prepared membranes is considered. It is found that the GPE based on the blended polymer with PVDF:CAB = 2:1 (in weight) has the largest ionic conductivity (2.48 × 10-3 S cm-1) and shows good compatibility with anode and cathode of lithium ion battery. The LiCoO2/graphite battery using this GPE exhibits superior cyclic stability at room temperature, storage performance at elevated temperature, and rate performance.

  1. Polydopamine coated electrospun poly(vinyldiene fluoride) nanofibrous membrane as separator for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Cao, Chengying; Tan, Lei; Liu, Weiwei; Ma, Jiquan; Li, Lei

    2014-02-01

    In this study, polydopamine (PDA) coated electrospun poly(vinyldiene fluoride) (PVDF) nanofibrous membranes used as separator for lithium-ion batteries are successfully prepared. Their morphology, chemical and electrochemical characterization are investigated. The morphology and porosity measurements of the membranes show that the PDA coating does not harm to the structure of the electrospun PVDF nanofibrous membranes. Due to the PDA coating, it makes the PVDF surface hydrophilic and thus increases the electrolyte uptake and ionic conductivity, resulting in the enhanced performance of batteries. The battery using the PDA coated PVDF nanofibrous separator exhibits better cycling performance and higher power capability than that the battery using the bare PVDF nanofibrous separator. This study underlines that the PDA-coating treatment provides a promising process for the fabrication of advanced electrospun nanofibers separator in the lithium-ion battery applications.

  2. Comparative Analysis between [(18)F]Fludarabine-PET and [(18)F]FDG-PET in a Murine Model of Inflammation.

    PubMed

    Hovhannisyan, Narinée; Dhilly, Martine; Guillouet, Stéphane; Leporrier, Michel; Barré, Louisa

    2016-06-06

    Lymphoma research has advanced thanks to introduction of [(18)F]fludarabine, a positron-emitting tool. This novel radiotracer has been shown to display a great specificity for lymphoid tissues. However, in a benign process such as inflammation, the uptake of this tracer has not been questioned. Indeed, in inflammatory zones, elevated glucose metabolism rate may result in false-positives with [(18)F]FDG-PET Imaging. In the present investigation, it has been argued that cells, involved in inflammation, might be less avid of [(18)F]fludarabine. To generate inflammation, Swiss mice were intramuscularly injected with 0.1 mL of turpentine oil into the right front paw. Imaging sessions with (18)F-labeled tracers named above were conducted on days 5 and 25 after inoculation. For each animal, volumes of interest (VOI), delineating the muscle of the inflamed (IP) and normal paws (NP), were determined on PET scans. For characterization of inflammation, muscle samples from IP and NP were stained with hematoxylin and eosin (H&E). In early (day 5) inflammation, [(18)F]FDG accumulation was 4.00 ± 1.65 times greater in the IP than in the contralateral NP; for [(18)F]fludarabine, this IP/NP ratio was 1.31 ± 0.28, resulting in a significant difference between radiotracer groups (p < 0.01). In late (day 25) inflammation, the IP/NP ratios were 2.07 ± 0.49 and 1.03 ± 0.07, for [(18)F]FDG and [(18)F]fludarabine, respectively (p < 0.001). [(18)F]Fludarabine showed significantly weaker uptake in inflammation when compared with [(18)F]FDG. This encouraging finding suggests that [(18)F]fludarabine-PET might well be a robust approach for distinguishing tumor from inflammatory tissue, avoiding false-positive PET results and thus enabling an accurate imaging of lymphoma.

  3. Ion-selective electrode in determining fluorine in binary fluorides of metals of groups II-V

    SciTech Connect

    Mishchenko, V.T.; Mukomel', V.L.; Polvektov, N.S.; Shilova, L.P.; Tselik, E.I.

    1986-01-01

    The authors have developed a method of determining fluorine by ion-selective electrode techniques in specimens containing mixtures of the fluorides of magnesium and the rare-earth elements (REE), as well as scandium and bismuth. The specimens after treatment at high temperatures are sparingly soluble at room temperature in water and also in aqueous solutions of acids and bases. The authors found that a mixture of KNaCO/sub 3/ and K/sub 2/S/sub 2/O/sub 8/ with a mass ratio of 2:1 was an effective flux for MgF/sub 2/-MeF/sub 3/ specimens, where Me is an REE ion. The combined method of analyzing binary mixtures of fluorides (Mg and REE, Sc and Bi) which provides satisfactory accuracy and reliability in determining the fluoride and two different metals whose compounds may have various ratios in the samples.

  4. Radiation absorbed dose estimates for 18F-BPA PET.

    PubMed

    Kono, Yuzuru; Kurihara, Hiroaki; Kawamoto, Hiroshi; Yasui, Naoko; Honda, Naoki; Igaki, Hiroshi; Itami, Jun

    2017-01-01

    Background Boron neutron capture therapy (BNCT) is a molecular radiation therapy approach based on the (10)B (n, α) (7)Li nuclear reaction in cancer cells. In BNCT, delivery of (10)B in the form of 4-borono-phenylalanine conjugated with fructose (BPA-fr) to the cancer cells is important. The PET tracer 4-borono-2-18F-fluoro-phenylalanine (FBPA) has been used to predict the accumulation of BPA-fr before BNCT. Purpose To determine the biodistribution and dosimetric parameters in 18F-BPA PET/CT studies. Material and Methods Human biokinetic data were obtained during clinical 18F-BPA PET studies between February and June 2015 at one institution. Nine consecutive patients were studied prospectively. The internal radiation dose was calculated on the basis of radioactivity data from blood, urine, and normal tissue of the heart, liver, spleen, kidney, and other parts of the body at each time point using OLINDA/EXM1.1 program. We compared our calculations with published 18F-FDG data. Results Adult patients (3 men, 3 women; age range, 28-68 years) had significantly smaller absorbed doses than pediatric patients (3 patients; age range, 5-12 years) ( P = 0.003). The mean effective dose was 57% lower in adult patients compared with pediatric patients. Mean effective doses for 18F-BPA were 25% lower than those for 18F-FDG presented in International Commission of Radiation Protection (ICRP) publication 106. Conclusion We found significant differences in organ absorbed doses for 18F-BPA against those for 18F-FDG presented in ICRP publication 106. Mean effective doses for 18F-BPA were smaller than those for 18F-FDG in the publication by 0.5-38% (mean difference, 25%).

  5. Pharmacokinetic evaluation of the tau PET radiotracer [18F]T807 ([18F]AV-1451) in human subjects.

    PubMed

    Wooten, Dustin; Guehl, Nicolas J; Verwer, Eline E; Shoup, Timothy M; Yokell, Daniel L; Zubcevik, Nevena; Vasdev, Neil; Zafonte, Ross D; Johnson, Keith A; El Fakhri, Georges; Normandin, Marc David

    2016-09-22

    [(18)F]T807 is a PET radiotracer developed for imaging tau protein aggregates, which are implicated in neurological disorders including Alzheimer's disease (AD) and traumatic brain injury (TBI). The current study characterizes [(18)F]T807 pharmacokinetics in human subjects using dynamic PET imaging and metabolite-corrected arterial input functions.

  6. Synthesis of hydroxyapatite/multi-walled carbon nanotubes for the removal of fluoride ions from solution

    NASA Astrophysics Data System (ADS)

    Ruan, Zhongyuan; Tian, Yaxi; Ruan, Jifu; Cui, Guijia; Iqbal, Kanwal; Iqbal, Anam; Ye, Herui; Yang, Zhangzhong; Yan, Shiqiang

    2017-08-01

    A novel composite material, hydroxyapatite (HA)-multi-walled carbon nanotubes (MWCNTs), was prepared using a simple in-situ sol-gel method, and was used for the first time to remove fluoride from water. The novel HA-MWCNTs were characterized using TEM, FT-IR, BET and XRD analysis. The TEM and SAED results revealed that the MWCNTs were uniformly encapsulated by hydroxyapatite nanoparticles. The synthesized HA-MWCNTs had a high specific surface area (180.504 m2 g-1), with an average pore width (14.607 nm) and pore volume (0.774 cm3 g-1), which produced a defluoridation capacity (DC) of 30.22 mgF- g-1. This value was greater than unmodified hydroxyapatite (HA), which exhibited a larger specific surface area (172.233 m2 g-1) and an excellent DC of 17.80 mgF- g-1. A number of pertinent parameters that could affect the defluoridation performance of the HA/MWCNTs including weight ratios of the two key materials, solution pH and competing anions were carefully and comprehensively examined. It was found that the adsorption results followed the Langmuir and Freundlich isotherm model, and the sorption kinetics of the F- appeared to exhibit a pseudo second order. Moreover, the adsorption reaction was spontaneous and endothermic and appeared to exhibit a higher initial adsorption rate. This reaction appeared to occur result from both anion exchange and electrostatic interactions. When the HA-MWCNTs (MH6) were at an adsorbent dose of 2.0 g L-1, they were able to decrease the fluoride concentration of actual nuclear industry wastewater from 8.79 mg L-1 to about 0.25 mg L-1 (97.15% removal efficiency). The experimental results of this study showed that the HA-MWCNTs composites have application potential for the removal of fluoride ions from wastewater.

  7. Fluoride absorption: independence from plasma fluoride levels

    SciTech Connect

    Whitford, G.M.; Williams, J.L.

    1986-04-01

    The concept that there are physiologic mechanisms to homeostatically regulate plasma fluoride concentrations has been supported by results in the literature suggesting an inverse relationship between plasma fluoride levels and the absorption of the ion from the gastrointestinal tract of the rat. The validity of the relationship was questioned because of possible problems in the experimental design. The present work used four different methods to evaluate the effect of plasma fluoride levels on the absorption of the ion in rats: (i) the percentage of the daily fluoride intake that was excreted in the urine; (ii) the concentration of fluoride in femur epiphyses; (iii) the net areas under the time-plasma fluoride concentration curves after intragastric fluoride doses; and (iv) the residual amounts or fluoride in the gastrointestinal tracts after the intragastric fluoride doses. None of these methods indicated that plasma fluoride levels influence the rate or the degree or fluoride absorption. It was concluded that, unless extremely high plasma fluoride levels are involved (pharmacologic or toxic doses), the absorption of the ion is independent of plasma levels. The results provide further evidence that plasma fluoride concentrations are not homeostatically regulated.

  8. Two-step radiosynthesis of 18)F]FE-β-CIT and [18F]PR04.MZ.

    PubMed

    Riss, Patrick J; Hoehnemann, Sabine; Piel, Markus; Roesch, Frank

    2013-06-15

    The cocaine-derived dopamine reuptake inhibitors FE-β-CIT (8-(2-fluoroethyl)-3-(4-iodophenyl)-8-azabicyclo[3.2.1]octane-2-carboxylic acid methyl ester) (1) and PR04.MZ(8-(4-fluorobut-2-ynyl)-3-p-tolyl-8-azabicyclo[3.2.1]octane-2-carboxylic acid methyl ester) (2) were labelled with (18)F-fluorine using a two-step route. 2-[(18)F]Fluoroethyltosylate and 4-[(18)F]fluorobut-2-yne-1-yl tosylate were used as labelling reagents, respectively. Radiochemically pure (>98%) [(18)F]FE-β-CIT and [(18)F]PRD04.MZ (32-86 GBq/µmol) were obtained after a synthesis time of 100 min in about 25% non-decay-corrected overall yield. Copyright © 2013 John Wiley & Sons, Ltd.

  9. Energy transfer kinetics in oxy-fluoride glass and glass-ceramics doped with rare-earth ions

    SciTech Connect

    Sontakke, Atul D.; Annapurna, K.

    2012-07-01

    An investigation of donor-acceptor energy transfer kinetics in dual rare earths doped precursor oxy-fluoride glass and its glass-ceramics containing NaYF{sub 4} nano-crystals is reported here, using three different donor-acceptor ion combinations such as Nd-Yb, Yb-Dy, and Nd-Dy. The precipitation of NaYF{sub 4} nano-crystals in host glass matrix under controlled post heat treatment of precursor oxy-fluoride glasses has been confirmed from XRD, FESEM, and transmission electron microscope (TEM) analysis. Further, the incorporation of dopant ions inside fluoride nano-crystals has been established through optical absorption and TEM-EDX analysis. The noticed decreasing trend in donor to acceptor energy transfer efficiency from precursor glass to glass-ceramics in all three combinations have been explained based on the structural rearrangements that occurred during the heat treatment process. The reduced coupling phonon energy for the dopant ions due to fluoride environment and its influence on the overall phonon assisted contribution in energy transfer process has been illustrated. Additionally, realization of a correlated distribution of dopant ions causing clustering inside nano-crystals has also been reported.

  10. sup 18 F-labeled insulin: A prosthetic group methodology for incorporation of a positron emitter into peptides and proteins

    SciTech Connect

    Shai, Y.; Kirk, K.L.; Channing, M.A.; Dunn, B.B.; Lesniak, M.A.; Eastman, R.C.; Finn, R.D.; Roth, J.; Jacobson, K.A. )

    1989-05-30

    In the present study we synthesize {sup 18}F-labeled insulin of high specific radioactivity. A new prosthetic group methodology, in which ({sup 18}F)fluoride displaces a bromide group of 4-(bromomethyl)-benzoylamine intermediates, was used. The 4-(fluoromethyl)benzoyl product was chemically stable. {sup 18}F-Labeled insulin retains the essential biological properties of native insulin, as measured in vitro by binding to insulin receptors on human cells and stimulation of glucose metabolism in rat adipocytes. The overall process can be carried out speedily to yield a product of sufficient purity to permit in vivo studies. The method appears to be applicable to a wide variety of peptides.

  11. 18F-Labeled Insulin: A Prosthetic Group Methodology for Incorporation of a Positron Emitter into Peptides and Proteins†

    PubMed Central

    Shai, Yechiel; Kirk, Kenneth L.; Channing, Michael A.; Dunn, Bonnie B.; Lesniak, Maxine A.; Eastman, Richard C.; Finn, Ronald D.; Roth, Jesse; Jacobson, Kenneth A.

    2012-01-01

    In the present study we synthesize 18F-labeled insulin of high specific radioactivity. A new prosthetic group methodology, in which [18F]fluoride displaces a bromide group of 4-(bromomethyl)-benzoylamine intermediates, was used. The 4-(fluoromethyl)benzoyl product was chemically stable. 18F-Labeled insulin retains the essential biological properties of native insulin, as measured in vitro by binding to insulin receptors on human cells and stimulation of glucose metabolism in rat adipocytes. The overall process can be carried out speedily to yield a product of sufficient purity to permit in vivo studies. The method appears to be applicable to a wide variety of peptides. PMID:2669963

  12. Automated synthesis and dosimetry of 6-deoxy-6-[18F]fluoro-D-fructose (6-[18F]FDF): a radiotracer for imaging of GLUT5 in breast cancer

    PubMed Central

    Bouvet, Vincent; Jans, Hans S; Wuest, Melinda; Soueidan, Olivier-Mohamad; Mercer, John; McEwan, Alexander JB; West, Frederick G; Cheeseman, Chris I; Wuest, Frank

    2014-01-01

    6-Deoxy-6-[18F]fluoro-D-fructose (6-[18F]FDF) is a promising PET radiotracer for imaging GLUT5 in breast cancer. The present work describes GMP synthesis of 6-[18F]FDF in an automated synthesis unit (ASU) and dosimetry calculations to determine radiation doses in humans. GMP synthesis and dosimetry calculations are important prerequisites for first-in-human clinical studies of 6-[18F]FDF. The radiochemical synthesis of 6-[18F]FDF was optimized and adapted to an automated synthesis process using a Tracerlab FXFN ASU (GE Healthcare). Starting from 30 GBq of cyclotron-produced n.c.a. [18F]fluoride, 2.9 ± 0.1 GBq of 6-[18F]FDF could be prepared within 50 min including HPLC purification resulting in an overall decay-corrected radiochemical yield of 14 ± 3% (n = 11). Radiochemical purity exceeded 95%, and the specific activity was greater than 5.1 GBq/μmol. Sprague-Dawley rats were used for biodistribution experiments, and dynamic and static small animal PET experiments. Biodistribution studies served as basis for allometric extrapolation to the standard man anatomic model and normal organ-absorbed dose calculations using OLINDA/EXM software. The calculated human effective dose for 6-[18F]FDF was 0.0089 mSv/MBq. Highest organ doses with a dose equivalent of 0.0315 mSv/MBq in a humans were found in bone. Injection of 370 MBq (10 mCi) of 6-[18F]FDF results in an effective whole body radiation dose of 3.3 mSv in humans, a value comparable to that of other 18F-labeled PET radiopharmaceuticals. The optimized automated synthesis under GMP conditions, the good radiochemical yield and the favorable human radiation dosimetry estimates support application of 6-[18F]FDF in clinical trials for molecular imaging of GLUT5 in breast cancer patients. PMID:24795839

  13. Displacement of the proton in hydrogen-bonded complexes of hydrogen fluoride by beryllium and magnesium ions

    SciTech Connect

    McDowell, Sean A. C.

    2009-05-14

    The displacement of the proton by a beryllium ion and by a magnesium ion from hydrogen-bonded complexes of hydrogen fluoride, of varying hydrogen bond strengths, was investigated theoretically using ab initio methods. Stable metal-containing species were obtained from all of the hydrogen-bonded complexes regardless of the strength of the hydrogen bond. It was found that the beryllium ion was energetically very effective in displacing the proton from hydrogen bonds, whereas the magnesium ion was unable to do so. The high stability of the beryllium-containing complexes is mainly due to the strong electrostatic bonding between the beryllium and fluoride atoms. This work supports the recent finding from a multidisciplinary bioinorganic study that beryllium displaces the proton in many strong hydrogen bonds.

  14. Displacement of the proton in hydrogen-bonded complexes of hydrogen fluoride by beryllium and magnesium ions.

    PubMed

    McDowell, Sean A C

    2009-05-14

    The displacement of the proton by a beryllium ion and by a magnesium ion from hydrogen-bonded complexes of hydrogen fluoride, of varying hydrogen bond strengths, was investigated theoretically using ab initio methods. Stable metal-containing species were obtained from all of the hydrogen-bonded complexes regardless of the strength of the hydrogen bond. It was found that the beryllium ion was energetically very effective in displacing the proton from hydrogen bonds, whereas the magnesium ion was unable to do so. The high stability of the beryllium-containing complexes is mainly due to the strong electrostatic bonding between the beryllium and fluoride atoms. This work supports the recent finding from a multidisciplinary bioinorganic study that beryllium displaces the proton in many strong hydrogen bonds.

  15. A novel fast ion chromatographic method for the analysis of fluoride in Antarctic snow and ice.

    PubMed

    Severi, Mirko; Becagli, Silvia; Frosini, Daniele; Marconi, Miriam; Traversi, Rita; Udisti, Roberto

    2014-01-01

    Ice cores are widely used to reconstruct past changes of the climate system. For instance, the ice core record of numerous water-soluble and insoluble chemical species that are trapped in snow and ice offer the possibility to investigate past changes of various key compounds present in the atmosphere (i.e., aerosol, reactive gases). We developed a new method for the quantitative determination of fluoride in ice cores at sub-μg L(-1) levels by coupling a flow injection analysis technique with a fast ion chromatography separation based on the "heart cut" column switching technology. Sensitivity, linear range (up to 60 μg L(-1)), reproducibility, and detection limit (0.02 μg L(-1)) were evaluated for the new method. This method was successfully applied to the analysis of fluoride at trace levels in more than 450 recent snow samples collected during the 1998-1999 International Trans-Antarctica Scientific Expedition traverse in East Antarctica at sites located between 170 and 850 km from the coastline.

  16. Trojan Horse Method and RIBs: The {sup 18}F(p,{alpha}){sup 15}O reaction at astrophysical energies

    SciTech Connect

    Cherubini, S.; Gulino, M.; Rapisarda, G. G.; Spitaleri, C.; La Cognata, M.; Lamia, L.; Kubono, S.; Yamaguchi, H.; Hayakawa, S.; Wakabayashi, Y.; Iwasa, N.; Kato, S.; Komatsubara, H.; Teranishi, T.; Coc, A.; De Sereville, N.; Hammache, F.

    2012-11-12

    The abundance of {sup 18}F in Nova explosions is an important issue for the understanding of this astrophysical phenomenon. For this reason it is necessary to study the nuclear reactions that produce or destroy this isotope in novae. Among these latter processes, the {sup 18}F(p,{alpha}){sup 15}O is one of the main {sup 18}F destruction channels. We report here on the preliminary results of the first experiment that applies the Trojan Horse Method to a Radioactive Ion Beam induced reaction. The experiment was performed using the CRIB apparatus of the Center for Nuclear Study of The Tokyo University.

  17. Trojan Horse Method and RIBs: The 18F(p,α)15O reaction at astrophysical energies

    NASA Astrophysics Data System (ADS)

    Cherubini, S.; Gulino, M.; Rapisarda, G. G.; Spitaleri, C.; La Cognata, M.; Lamia, L.; Kubono, S.; Yamaguchi, H.; Hayakawa, S.; Wakabayashi, Y.; Iwasa, N.; Kato, S.; Komatsubara, H.; Teranishi, T.; Coc, A.; De Séréville, N.; Hammache, F.

    2012-11-01

    The abundance of 18F in Nova explosions is an important issue for the understanding of this astrophysical phenomenon. For this reason it is necessary to study the nuclear reactions that produce or destroy this isotope in novae. Among these latter processes, the 18F(p,α)15O is one of the main 18F destruction channels. We report here on the preliminary results of the first experiment that applies the Trojan Horse Method to a Radioactive Ion Beam induced reaction. The experiment was performed using the CRIB apparatus of the Center for Nuclear Study of The Tokyo University.

  18. (18)F-labelled metomidate analogues as adrenocortical imaging agents.

    PubMed

    Erlandsson, Maria; Karimi, Farhad; Lindhe, Orjan; Långström, Bengt

    2009-05-01

    Two- and one-step syntheses of (18)F-labelled analogues of metomidate, such as 2-[(18)F]fluoroethyl 1-[(1R)-1-phenylethyl]-1H-imidazole-5-carboxylate (1), 2-[(18)F]fluoroethyl 1-[(1R)-1-(4-chlorophenyl)ethyl]-1H-imidazole-5-carboxylate (2), 2-[(18)F]fluoroethyl 1-[(1R)-1-(4-bromophenyl)ethyl]-1H-imidazole-5-carboxylate (3), 3-[(18)F]fluoropropyl 1-[(1R)-1-(4-bromophenyl)ethyl]-1H-imidazole-5-carboxylate (4) and 3-[(18)F]fluoropropyl 1-[(1R)-1-phenylethyl]-1H-imidazole-5-carboxylate (5) are presented. Analogues 1-5 were prepared by a two-step reaction sequence that started with the synthesis of either 2-[(18)F]fluoroethyl 4-methylbenzenesulfonate or 3-[(18)F]fluoropropyl 4-methylbenzenesulfonate. These were used as (18)F-alkylating agents in the second step, in which they reacted with the ammonium salt of a 1-[(1R)-1-phenylethyl]-1H-imidazole-5-carboxylic acid. One-step-labelling syntheses of 1, 2 and 5 were also explored. Analogues 1-4 were biologically validated by frozen-section autoradiography and organ distribution. Metabolite analysis was performed for 2 and 3. The radiochemical yield of the two-step synthesis was in the range of 10-29% and that of the one-step synthesis was 25-37%. Using microwave irradiation in the one-step synthesis of 1 and 2 increased the radiochemical yield to 46+/-3% and 79+/-30%, respectively. Both the frozen-section autoradiography and organ distribution results indicated that analogue 2 has a potential as an adrenocortical imaging agent, having the highest degree of specific adrenal binding and best ratio of adrenal to organ uptake among the compounds studied.

  19. In vivo biodistribution of two ( sup 18 F)-labelled muscarinic cholinergic receptor ligands: 2-( sup 18 F)- and 4-( sup 18 F)-fluorodexetimide

    SciTech Connect

    Wilson, A.A.; Scheffel, U.A.; Dannals, R.F.; Stathis, M.; Ravert, H.T.; Wagner, H.N. Jr. )

    1991-01-01

    Two ({sup 18}F)-labelled analogues of the potent muscarinic cholinergic receptor (m-AChR) antagonist, dexetimide, were evaluated as potential ligands for imaging m-AChR by positron emission tomography (PET). Intravenous administration of both 2-({sup 18}F)- or 4-({sup 18}F)-fluorodexetimide resulted in high brain uptake of radioactivity in mice. High binding levels were observed in m-AChR rich areas, such as cortex and striatum, with low levels in the receptor-poor cerebellum. Uptake of radioactivity was saturable and could be blocked by pre-administration of dexetimide or atropine. Drugs with different sites of action were ineffective at blocking receptor binding. The results indicate that both radiotracers are promising candidates for use in PET studies.

  20. Preliminary biological evaluation of (18)F-AlF-NOTA-MAL-Cys-Annexin V as a novel apoptosis imaging agent.

    PubMed

    Lu, Chunxiong; Jiang, Quanfu; Hu, Minjin; Tan, Cheng; Yu, Huixin; Hua, Zichun

    2017-08-01

    A novel annexin V derivative (Cys-Annexin V) with a single cysteine residue at its C-terminal has been successfully labeled site-specifically with NOTA-maleimide aluminum [(18)F]fluoride complexation and evaluated it as a novel apoptosis agent in vitro and in vivo. The total synthesis time of (18)F-AlF-NOTA-MAL-Cys-Annexin V from [(18)F]fluoride was about 65 min. The tracer was stable in vitro and it was excreted through renal in normal mice. The rate of the tracer bound to erythrocytes with exposed phosphatidylserine was 89.36±0.61% and this binding could be blocked by unlabeled Cys-Annexin V. In rats treated with cycloheximide, there were 6.23±0.23 times (n=4) increase in hepatic uptake of the tracer as compared to normal rats at 1h p.i. The uptake of the tracer in liver also could be blocked by co-injection of unlabeled Cys-Annexin V. These results indicated the favorable characterizations such as convenient synthesis and specific apoptotic cells targeting of(18)F-AlF-NOTA-MAL- Cys-Annexin V were suitable for its further investigation in clinical apoptosis imaging.

  1. Vacuum ultraviolet field emission lamp consisting of neodymium ion doped lutetium fluoride thin film as phosphor.

    PubMed

    Yanagihara, Masahiro; Tsuji, Takayuki; Yusop, Mohd Zamri; Tanemura, Masaki; Ono, Shingo; Nagami, Tomohito; Fukuda, Kentaro; Suyama, Toshihisa; Yokota, Yuui; Yanagida, Takayuki; Yoshikawa, Akira

    2014-01-01

    A vacuum ultraviolet (VUV) field emission lamp was developed by using a neodymium ion doped lutetium fluoride (Nd(3+) : LuF3) thin film as solid-state phosphor and carbon nanofiber field electron emitters. The thin film was synthesized by pulsed laser deposition and incorporated into the lamp. The cathodoluminescence spectra of the lamp showed multiple emission peaks at 180, 225, and 255 nm. These emission spectra were in good agreement with the spectra reported for the Nd(3+) : LuF3 crystal. Moreover, application of an acceleration voltage effectively increased the emission intensity. These results contribute to the performance enhancement of the lamp operating in the VUV region.

  2. Polyvinilidine fluoride (PVDF) nanofiber membrane for Li-ion rechargeable battery separator

    NASA Astrophysics Data System (ADS)

    Widiyandari, H.; Purwanto, A.; Widyanto, S. A.

    2017-04-01

    This study reported synthesis and characterization of PVDF (polyvinilidine fluoride) nanofiber membrane using electrospinning method for Li-ion rechargeable battery separator. Electrospinning equipment system consists of a DC high voltage (HV - DC), a controllable spinner and a plate collector. The effects of the applied voltage on morphological property, porosity and thermal property were systematically investigated. The application of DC voltage at a range of 13 to 17 kV resulted the one-dimension nanostructure of the PVdF nanofiber. The produced PVdF nanofiber membrane separators are evaluated to have a higher level of porosity (86 - 93%) and a good thermal shrinkage property in comparison to Polypropylene (PP) microporous membrane separator. The produced PVdF membrane separators were assembled into the LiFePO4 cells and demonstrated high charge-discharge capacities at room temperature with the coulombic efficiency reaching 80 %.

  3. Vacuum Ultraviolet Field Emission Lamp Consisting of Neodymium Ion Doped Lutetium Fluoride Thin Film as Phosphor

    PubMed Central

    Yanagihara, Masahiro; Tsuji, Takayuki; Yusop, Mohd Zamri; Tanemura, Masaki; Nagami, Tomohito; Fukuda, Kentaro; Suyama, Toshihisa; Yokota, Yuui; Yanagida, Takayuki; Yoshikawa, Akira

    2014-01-01

    A vacuum ultraviolet (VUV) field emission lamp was developed by using a neodymium ion doped lutetium fluoride (Nd3+ : LuF3) thin film as solid-state phosphor and carbon nanofiber field electron emitters. The thin film was synthesized by pulsed laser deposition and incorporated into the lamp. The cathodoluminescence spectra of the lamp showed multiple emission peaks at 180, 225, and 255 nm. These emission spectra were in good agreement with the spectra reported for the Nd3+ : LuF3 crystal. Moreover, application of an acceleration voltage effectively increased the emission intensity. These results contribute to the performance enhancement of the lamp operating in the VUV region. PMID:25302320

  4. [The comparison of luminescence properties for Ce3+, Tb3+ ions in the fluorides].

    PubMed

    Wu, G; Chen, R; Zhang, Q

    2000-08-01

    The matrix K3AlF6 was prepared with a reaction of mixture of solution K2CO3 upon certain solution of Al(OH)3 plus HF (40%), dehydrating at 100 degrees C and annealing for 48 h at 600 degrees C. A series of phosphors for Ce3+, Tb3+ ions in complex fluorides KBF4 and K3AlF6 were synthesized by a solid reaction method. Their excitation and emission spectra were determined, compared with phosphors KAlF4: Ce, Tb, CaF2: Ce, Tb and AlF3: Ce, Tb. The results indicated that Ce3+ could only effectively sensitize Tb3+ in KAlF4 and enhance the emission of Tb3+ significantly. Ce3+ can not effectvely transfer energy to Tb3+ in matrixes CaF2, AlF3, KBF4 and K3AlF6.

  5. Small Prosthetic Groups in (18)F-Radiochemistry: Useful Auxiliaries for the Design of (18)F-PET Tracers.

    PubMed

    Schirrmacher, Ralf; Wängler, Björn; Bailey, Justin; Bernard-Gauthier, Vadim; Schirrmacher, Esther; Wängler, Carmen

    2017-09-01

    Prosthetic group (PG) applications in (18)F-radiochemistry play a pivotal role among current (18)F(-)labeling techniques for the development and availability of (18)F-labeled imaging probes for PET (Wahl, 2002) ((1)). The introduction and popularization of PGs in the mid-80s by pioneers in (18)F-radiochemistry has profoundly changed the landscape of available tracers for PET and has led to a multitude of new imaging agents based on simple and efficiently synthesized PGs. Because of the chemical nature of anionic (18)F(-) (apart from electrophilic low specific activity (18)F-fluorine), radiochemistry before the introduction of PGs was limited to simple nucleophilic substitutions of leaving group containing precursor molecules. These precursors were not always available, and some target compounds were either hard to synthesize or not obtainable at all. Even with the advent of recently introduced "late-stage fluorination" techniques for the (18)F-fluorination of deactivated aromatic systems, PGs will continue to play a central role in (18)F-radiochemistry because of their robust and almost universal usability. The importance of PGs in radiochemistry is shown by its current significance in tracer development and exemplified by an overview of selected methodologies for PG attachment to PET tracer molecules. Especially, click-chemistry approaches to PG conjugation, while furthering the historical evolution of PGs in PET tracer design, play a most influential role in modern PG utilization. All earlier and recent multifaceted approaches in PG development have significantly enriched the contingent of modern (18)F-radiochemistry procedures and will continue to do so. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. High 18F-fluorodeoxyglucose (18F-FDG) uptake in microscopic peritoneal tumors requires physiological hypoxia

    PubMed Central

    Li, Xiao-Feng; Ma, Yuanyuan; Sun, Xiaorong; Humm, John L.; Ling, C. Clifton; O’Donoghue, Joseph A.

    2010-01-01

    The objective of this study was to examine 18F-fluorodeoxyglucose (18F-FDG) uptake in microscopic tumors grown intraperitoneally in nude mice and to relate this to physiological hypoxia and glucose transporter-1 (GLUT-1) expression. Methods Human colon cancer HT29 and HCT-8 cells were injected intraperitoneally into nude mice to generate disseminated tumors of varying sizes. Following overnight fasting, animals, either breathing air or carbogen (95% O2+ 5% CO2), were intravenously administered 18F-FDG together with the hypoxia marker pimonidazole (PIMO) and the cellular proliferation marker bromodeoxyuridine (BrdUrd) one hour before sacrifice. Hoechst 33342, a perfusion marker, was administered one minute before sacrifice. Following sacrifice, the intratumoral distribution of 18F-FDG was assessed by digital autoradiography of frozen tissue sections. This was compared with the distributions of PIMO, GLUT-1 expression, BrdUrd and Hoechst 33342 as visualized by immunofluorescent microscopy. Results Small tumors (< 1 mm diameter) had high 18F-FDG accumulation and were severely hypoxic with high GLUT-1 expression. Larger tumors (1–4 mm diameter) generally had low 18F-FDG accumulation and were not significantly hypoxic with low GLUT1 expression. Carbogen breathing significantly decreased 18F-FDG accumulation and tumor hypoxia in microscopic tumors but had little effect on GLUT1 expression. Conclusion There was high 18F-FDG uptake in microscopic tumors which was spatially associated with physiological hypoxia and high GLUT-1 expression. This enhanced uptake was abrogated by carbogen breathing, indicating that in the absence of physiological hypoxia, high GLUT1 expression, by itself, was insufficient to ensure high 18F-FDG uptake. PMID:20351353

  7. Comparison Study of [18F]FAl-NOTA-PRGD2, [18F]FPPRGD2 and [68Ga]Ga-NOTA-PRGD2 for PET Imaging of U87MG Tumors in Mice

    PubMed Central

    Lang, Lixin; Li, Weihua; Guo, Ning; Ma, Ying; Zhu, Lei; Kiesewetter, Dale O.; Shen, Baozhong; Niu, Gang; Chen, Xiaoyuan

    2011-01-01

    [18F]FPPRGD2, an F-18 labeled dimeric cyclic RGDyK peptide, has favorable properties for PET imaging of angiogenesis by targeting the αvβ3 integrin receptor. This radiotracer has been approved by the FDA for use in clinical trials. However, the time-consuming multiple-step synthetic procedure required for its preparation may hinder the widespread usage of this tracer. The recent development of a method using an F-18 fluoride-aluminum complex to radiolabel peptides provides a strategy for simplifying the labeling procedure. On the other hand, the easy-to-prepare [68Ga]-labeled NOTA-RGD derivatives have also been reported to have promising properties for imaging αvβ3 integrin receptors. The purpose of this study was to prepare [18F]FPPRDG2, [18F]FAl-NOTA-PRGD2, and [68Ga]Ga-NOTA-PRGD2 and to compare their pharmacokinetics and tumor imaging properties using small animal PET. All three compounds showed rapid and high tracer uptake in U87MG tumors with high target-to-background ratios. The uptake in the liver, kidneys and muscle were similar for all three tracers and they all showed predominant renal clearance. In conclusion, [18F]FAl-NOTA-PRGD2 and [68Ga]Ga-NOTA-PRGD2 have imaging properties and pharmacokinetics comparable to those of [18F]FPPRGD2. Considering their ease of preparation and good imaging qualities, [18F]FAl-NOTA-PRGD2 and [68Ga]NOTA-PRGD2 are promising alternatives to [18F]FPPRGD2 for PET imaging of tumor αvβ3 integrin expression. PMID:22026940

  8. Comparison study of [18F]FAl-NOTA-PRGD2, [18F]FPPRGD2, and [68Ga]Ga-NOTA-PRGD2 for PET imaging of U87MG tumors in mice.

    PubMed

    Lang, Lixin; Li, Weihua; Guo, Ning; Ma, Ying; Zhu, Lei; Kiesewetter, Dale O; Shen, Baozhong; Niu, Gang; Chen, Xiaoyuan

    2011-12-21

    [(18)F]FPPRGD2, an F-18 labeled dimeric cyclic RGDyK peptide, has favorable properties for PET imaging of angiogenesis by targeting the α(v)β(3) integrin receptor. This radiotracer has been approved by the FDA for use in clinical trials. However, the time-consuming multiple-step synthetic procedure required for its preparation may hinder the widespread usage of this tracer. The recent development of a method using an F-18 fluoride-aluminum complex to radiolabel peptides provides a strategy for simplifying the labeling procedure. On the other hand, the easy-to-prepare [(68)Ga]-labeled NOTA-RGD derivatives have also been reported to have promising properties for imaging α(v)β(3) integrin receptors. The purpose of this study was to prepare [(18)F]FPPRGD2 [corrected] , [(18)F]FAl-NOTA-PRGD2, and [(68)Ga]Ga-NOTA-PRGD2 and to compare their pharmacokinetics and tumor imaging properties using small animal PET. All three compounds showed rapid and high tracer uptake in U87MG tumors with high target-to-background ratios. The uptake in the liver, kidneys, and muscle were similar for all three tracers, and they all showed predominant renal clearance. In conclusion, [(18)F]FAl-NOTA-PRGD2 and [(68)Ga]Ga-NOTA-PRGD2 have imaging properties and pharmacokinetics comparable to those of [(18)F]FPPRGD2. Considering their ease of preparation and good imaging qualities, [(18)F]FAl-NOTA-PRGD2 and [(68)Ga]NOTA-PRGD2 are promising alternatives to [(18)F]FPPRGD2 for PET imaging of tumor α(v)β(3) integrin expression.

  9. Concerted nucleophilic aromatic substitution with 19F- and 18F-

    NASA Astrophysics Data System (ADS)

    Neumann, Constanze N.; Hooker, Jacob M.; Ritter, Tobias

    2016-06-01

    Nucleophilic aromatic substitution (SNAr) is widely used by organic chemists to functionalize aromatic molecules, and it is the most commonly used method to generate arenes that contain 18F for use in positron-emission tomography (PET) imaging. A wide range of nucleophiles exhibit SNAr reactivity, and the operational simplicity of the reaction means that the transformation can be conducted reliably and on large scales. During SNAr, attack of a nucleophile at a carbon atom bearing a ‘leaving group’ leads to a negatively charged intermediate called a Meisenheimer complex. Only arenes with electron-withdrawing substituents can sufficiently stabilize the resulting build-up of negative charge during Meisenheimer complex formation, limiting the scope of SNAr reactions: the most common SNAr substrates contain strong π-acceptors in the ortho and/or para position(s). Here we present an unusual concerted nucleophilic aromatic substitution reaction (CSNAr) that is not limited to electron-poor arenes, because it does not proceed via a Meisenheimer intermediate. We show a phenol deoxyfluorination reaction for which CSNAr is favoured over a stepwise displacement. Mechanistic insights enabled us to develop a functional-group-tolerant 18F-deoxyfluorination reaction of phenols, which can be used to synthesize 18F-PET probes. Selective 18F introduction, without the need for the common, but cumbersome, azeotropic drying of 18F, can now be accomplished from phenols as starting materials, and provides access to 18F-labelled compounds not accessible through conventional chemistry.

  10. Effect of humic substances aggregation on the determination of fluoride in water using an ion selective electrode.

    PubMed

    Shen, Junjie; Gagliardi, Simona; McCoustra, Martin R S; Arrighi, Valeria

    2016-09-01

    The control of drinking water quality is critical in preventing fluorosis. In this study humic substances (HS) are considered as representative of natural organic matter (NOM) in water. We show that when HS aggregate the response of fluoride ion selective electrodes (ISE) may be perturbed. Dynamic light scattering (DLS) results of both synthetic solutions and natural water sample suggest that low pH and high ionic strength induce HS aggregation. In the presence of HS aggregates, fluoride concentration measured by ISE has a reduction up to 19%. A new "open cage" concept has been developed to explain this reversible phenomenon. The interference of HS aggregation on fluoride measurement can be effectively removed by centrifugation pretreatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. In Situ Response of Nanostructured Hybrid Fluoridated Restorative Composites on Enamel Demineralization, Surface Roughness and Ion Release.

    PubMed

    Melo, Mary A S; Codes, Bruna M; Passos, Vanara F; Lima, Juliana P M; Rodrigues, Lidiany K A

    2014-12-01

    Recurrent caries at the tooth-restoration margins is the main reason for composite failure. Fluoride-releasing nanohybrid composite resin may reduce the recurrent caries rates. A fluoride-releasing resin (FCR) and non-fluoride-releasing resin (CR) were tested using an in situ model. Demineralization (ΔS), ion release and surface roughness of composite specimens were determined. The F concentration in the group FCR was higher than the CR group. ΔS (Mean ± SD) was 2579 ± 1582 and 1705 ± 1292, respectively, for FCR and CR. Surfaces roughness was altered by biofilm accumulation. The hybrid fluorated restorative composites containing nanoparticles have a slight anticaries action without alteration of surface smoothness of the material.

  12. Design of an Automated System for Synthesis of [18 F] FDG for PET Investigation at IFIN-HH Bucharest

    NASA Astrophysics Data System (ADS)

    Craciun, Liviu Stefan; Cimpeanu, Catalina; Constantinescu, Olimpiu; Dudu, Dorin; Ionescu, Cristina; Negoita, Nicolae; Racolta, Petru Mihai; Rusen, Ion

    2009-03-01

    A novel apparatus constructed at IFIN-HH is described for automated synthesis of radiopharmaceuticals labeled with 18F for use in positron emission tomography (PET) investigations. [18 F] fluoride was produced at the IFIN-HH cyclotron by irradiation of H2O enriched 97% in 18O with 13 MeV deuterons, or 8 MeV protons. The irradiated H2O was transferred (injected) into the radiochemical fully-automated processing systems which ensured the separation of 18F from H2O, the labeling with 18F, and finally purified by filtration with selective absorbants. The system is easy to operate and contains a programmable logical controller that manages the entire operation program stored in its internal memory. The computer is used to assist the operator during the different steps of synthesis and to allow visualization of the process and printing the report. The device was used for used for the production of 2-[18 F] FLUORO-2-DEOXY-D-GLUCOSE at the IFIN-HH cyclotron, one of the most used radiopharmaceutical in PET investigations. The synthesis module is configured so that is flexible enough to accomplish other nucleophile reactions of labeling with short lived radioisotopes.

  13. A novel sulfonated prosthetic group for [18F]-radiolabelling and imparting water solubility of biomolecules and cyanine fluorophores.

    PubMed

    Priem, Thomas; Bouteiller, Cédric; Camporese, Davide; Brune, Xavier; Hardouin, Julie; Romieu, Anthony; Renard, Pierre-Yves

    2013-01-21

    Synthesis and some applications of a novel [(18)F]-fluorinated prosthetic group based on the promising sultone radiochemistry and suitable for the labelling of amine-containing (bio)chemical compounds are described. The combined sequential use of two easy and efficient conjugation reactions namely the fluoride ring-opening of a 1,3-propanesultone moiety and the aminolysis of an N-hydroxysuccinimidyl ester is the key component of this original radiolabelling strategy. The mild reaction conditions and the release of a free sulfonic acid moiety as a result of the [(18)F]-induced sultone ring-opening reaction, both make this [(18)F]-conjugation method suitable for the radiofluorination of fragile and hydrophobic biomolecules and fluorophores, particularly by making the separation of the targeted [(18)F]-tagged sulfonated compound from its starting precursor easier and thus faster. The ability of this unusual prosthetic group to readily introduce the radioisotope within complex (bio)molecular architectures has been demonstrated by (1) the preparation of the first [(18)F]-labelled cyanine 5.5 (Cy 5.5) dye, a suitable precursor for the construction of hybrid positron emission tomography/near-infrared fluorescence (PET/NIRF) imaging probes and (2) the radiolabelling of a biologically relevant peptide bearing a single lysine residue.

  14. Design of an Automated System for Synthesis of [18 F] FDG for PET Investigation at IFIN-HH Bucharest

    SciTech Connect

    Craciun, Liviu Stefan; Cimpeanu, Catalina; Constantinescu, Olimpiu; Dudu, Dorin; Ionescu, Cristina; Negoita, Nicolae; Racolta, Petru Mihai; Rusen, Ion

    2009-03-10

    A novel apparatus constructed at IFIN-HH is described for automated synthesis of radiopharmaceuticals labeled with {sup 18}F for use in positron emission tomography (PET) investigations. [18 F] fluoride was produced at the IFIN-HH cyclotron by irradiation of H{sub 2}O enriched 97% in {sup 18}O with 13 MeV deuterons, or 8 MeV protons. The irradiated H{sub 2}O was transferred (injected) into the radiochemical fully-automated processing systems which ensured the separation of {sup 18}F from H{sub 2}O, the labeling with {sup 18}F, and finally purified by filtration with selective absorbants. The system is easy to operate and contains a programmable logical controller that manages the entire operation program stored in its internal memory. The computer is used to assist the operator during the different steps of synthesis and to allow visualization of the process and printing the report. The device was used for used for the production of 2-[18 F] FLUORO-2-DEOXY-D-GLUCOSE at the IFIN-HH cyclotron, one of the most used radiopharmaceutical in PET investigations. The synthesis module is configured so that is flexible enough to accomplish other nucleophile reactions of labeling with short lived radioisotopes.

  15. Lithium-fluoride flashover ion source cleaned with a glow discharge and irradiated with vacuum-ultraviolet radiation

    SciTech Connect

    Burns, E.J.T.; Woodworth, J.R.; Bieg, K.W.; Mehlhorn, T.A.; Stygar, W.A.; Sweeney, M.A.

    1988-01-01

    We have studied methods of varying the ion species generated by a lithium-fluoride overcoated anode in a 0.5-MV magnetically insulated ion diode. We found that cleaning the anode surface with a 13.6-MHz rf glow discharge or illuminating the anode with a pulsed soft x-ray, vacuum-ultraviolet (XUV) radiation source just before the accelerator pulse significantly altered the ion species of the ion beam produced by the diode. The glow-discharge plasma removed adsorbates (carbon, hydrogen, and oxygen) from the surface of the LiF flashover source. The ions seen were lithium and hydrogen. Unfortunately, the diode impedance with a lithium-fluoride anode was high and the ion efficiency was low; however, XUV irradiation of the surface dramatically lowered the impedance by desorbing neutrals from the ion source via photon-stimulated desorption. Current densities of ten times the Child--Langmuir space-charge limit were achieved under XUV irradiation. In particular, ion currents increased by over a factor of 3 when 12 mJ/cm/sup 2/ of XUV radiation was used. However, with XUV irradiation the largest fraction of ions were fluorine, oxygen, carbon, and hydrogen, not lithium.

  16. Quantitative analysis and comparison study of [18F]AlF-NOTA-PRGD2, [18F]FPPRGD2 and [68Ga]Ga-NOTA-PRGD2 using a reference tissue model.

    PubMed

    Guo, Ning; Lang, Lixin; Li, Weihua; Kiesewetter, Dale O; Gao, Haokao; Niu, Gang; Xie, Qingguo; Chen, Xiaoyuan

    2012-01-01

    With favorable pharmacokinetics and binding affinity for α(v)β(3) integrin, (18)F-labeled dimeric cyclic RGD peptide ([(18)F]FPPRGD2) has been intensively used as a PET imaging probe for lesion detection and therapy response monitoring. A recently introduced kit formulation method, which uses an (18)F-fluoride-aluminum complex labeled RGD tracer ([(18)F]AlF-NOTA-PRGD2), provides a strategy for simplifying the labeling procedure to facilitate clinical translation. Meanwhile, an easy-to-prepare (68)Ga-labeled NOTA-PRGD2 has also been reported to have promising properties for imaging integrin α(v)β(3). The purpose of this study is to quantitatively compare the pharmacokinetic parameters of [(18)F]FPPRGD2, [(18)F]AlF-NOTA-PRGD2, and [(68)Ga]Ga-NOTA-PRGD2. U87MG tumor-bearing mice underwent 60-min dynamic PET scans following the injection of three tracers. Kinetic parameters were calculated using Logan graphical analysis with reference tissue. Parametric maps were generated using voxel-level modeling. All three compounds showed high binding potential (Bp(ND) = k(3)/k(4)) in tumor voxels. [(18)F]AlF-NOTA-PRGD2 showed comparable Bp(ND) value (3.75±0.65) with those of [(18)F]FPPRGD2 (3.39±0.84) and [(68)Ga]Ga-NOTA-PRGD2 (3.09±0.21) (p>0.05). Little difference was found in volume of distribution (V(T)) among these three RGD tracers in tumor, liver and muscle. Parametric maps showed similar kinetic parameters for all three tracers. We also demonstrated that the impact of non-specific binding could be eliminated in the kinetic analysis. Consequently, kinetic parameter estimation showed more comparable results among groups than static image analysis. In conclusion, [(18)F]AlF-NOTA-PRGD2 and [(68)Ga]Ga-NOTA-PRGD2 have comparable pharmacokinetics and quantitative parameters compared to those of [(18)F]FPPRGD2. Despite the apparent difference in tumor uptake (%ID/g determined from static images) and clearance pattern, the actual specific binding component extrapolated

  17. Quantitative Analysis and Comparison Study of [18F]AlF-NOTA-PRGD2, [18F]FPPRGD2 and [68Ga]Ga-NOTA-PRGD2 Using a Reference Tissue Model

    PubMed Central

    Guo, Ning; Lang, Lixin; Li, Weihua; Kiesewetter, Dale O.; Gao, Haokao; Niu, Gang; Xie, Qingguo; Chen, Xiaoyuan

    2012-01-01

    With favorable pharmacokinetics and binding affinity for αvβ3 integrin, 18F-labeled dimeric cyclic RGD peptide ([18F]FPPRGD2) has been intensively used as a PET imaging probe for lesion detection and therapy response monitoring. A recently introduced kit formulation method, which uses an 18F-fluoride-aluminum complex labeled RGD tracer ([18F]AlF-NOTA-PRGD2), provides a strategy for simplifying the labeling procedure to facilitate clinical translation. Meanwhile, an easy-to-prepare 68Ga-labeled NOTA-PRGD2 has also been reported to have promising properties for imaging integrin αvβ3. The purpose of this study is to quantitatively compare the pharmacokinetic parameters of [18F]FPPRGD2, [18F]AlF-NOTA-PRGD2, and [68Ga]Ga-NOTA-PRGD2. U87MG tumor-bearing mice underwent 60-min dynamic PET scans following the injection of three tracers. Kinetic parameters were calculated using Logan graphical analysis with reference tissue. Parametric maps were generated using voxel-level modeling. All three compounds showed high binding potential (BpND = k3/k4) in tumor voxels. [18F]AlF-NOTA-PRGD2 showed comparable BpND value (3.75±0.65) with those of [18F]FPPRGD2 (3.39±0.84) and [68Ga]Ga-NOTA-PRGD2 (3.09±0.21) (p>0.05). Little difference was found in volume of distribution (VT) among these three RGD tracers in tumor, liver and muscle. Parametric maps showed similar kinetic parameters for all three tracers. We also demonstrated that the impact of non-specific binding could be eliminated in the kinetic analysis. Consequently, kinetic parameter estimation showed more comparable results among groups than static image analysis. In conclusion, [18F]AlF-NOTA-PRGD2 and [68Ga]Ga-NOTA-PRGD2 have comparable pharmacokinetics and quantitative parameters compared to those of [18F]FPPRGD2. Despite the apparent difference in tumor uptake (%ID/g determined from static images) and clearance pattern, the actual specific binding component extrapolated from kinetic modeling appears to be comparable

  18. Newer PET application with an old tracer: role of 18F-NaF skeletal PET/CT in oncologic practice.

    PubMed

    Bastawrous, Sarah; Bhargava, Puneet; Behnia, Fatemeh; Djang, David S W; Haseley, David R

    2014-01-01

    The skeleton is one of the most common sites for metastatic disease, particularly from breast and prostate cancer. Bone metastases are associated with considerable morbidity, and accurate imaging of the skeleton is important in determining the appropriate therapeutic plan. Sodium fluoride labeled with fluorine 18 (sodium fluoride F 18 [(18)F-NaF]) is a positron-emitting radiopharmaceutical first introduced several decades ago for skeletal imaging. (18)F-NaF was approved for clinical use as a positron emission tomographic (PET) agent by the U.S. Food and Drug Administration in 1972. The early use of this agent was limited, given the difficulties of imaging its high-energy photons on the available gamma cameras. For skeletal imaging, it was eventually replaced by technetium 99m ((99m)Tc)-labeled agents because of the technical limitations of (18)F-NaF. During the past several years, the widespread availability and implementation of hybrid PET and computed tomographic (CT) dual-modality systems (PET/CT) have encouraged a renewed interest in (18)F-NaF PET/CT for routine clinical use in bone imaging. Because current PET/CT systems offer high sensitivity and spatial resolution, the use of (18)F-NaF has been reevaluated for the detection of malignant and nonmalignant osseous disease. Growing evidence suggests that (18)F-NaF PET/CT provides increased sensitivity and specificity in the detection of bone metastases. Furthermore, the favorable pharmacokinetics of (18)F-NaF, combined with the superior imaging characteristics of PET/CT, supports the routine clinical use of (18)F-NaF PET/CT for oncologic imaging for skeletal metastases. In this article, a review of the indications, imaging appearances, and utility of (18)F-NaF PET/CT in the evaluation of skeletal disease is provided, with an emphasis on oncologic imaging.

  19. Automation of [(18) F]fluoroacetaldehyde synthesis: application to a recombinant human interleukin-1 receptor antagonist (rhIL-1RA).

    PubMed

    Morris, Olivia; McMahon, Adam; Boutin, Herve; Grigg, Julian; Prenant, Christian

    2016-06-15

    [(18) F]Fluoroacetaldehyde is a biocompatible prosthetic group that has been implemented pre-clinically using a semi-automated remotely controlled system. Automation of radiosyntheses permits use of higher levels of [(18) F]fluoride whilst minimising radiochemist exposure and enhancing reproducibility. In order to achieve full-automation of [(18) F]fluoroacetaldehyde peptide radiolabelling, a customised GE Tracerlab FX-FN with fully programmed automated synthesis was developed. The automated synthesis of [(18) F]fluoroacetaldehyde is carried out using a commercially available precursor, with reproducible yields of 26% ± 3 (decay-corrected, n = 10) within 45 min. Fully automated radiolabelling of a protein, recombinant human interleukin-1 receptor antagonist (rhIL-1RA), with [(18) F]fluoroacetaldehyde was achieved within 2 h. Radiolabelling efficiency of rhIL-1RA with [(18) F]fluoroacetaldehyde was confirmed using HPLC and reached 20% ± 10 (n = 5). Overall RCY of [(18) F]rhIL-1RA was 5% ± 2 (decay-corrected, n = 5) within 2 h starting from 35 to 40 GBq of [(18) F]fluoride. Specific activity measurements of 8.11-13.5 GBq/µmol were attained (n = 5), a near three-fold improvement of those achieved using the semi-automated approach. The strategy can be applied to radiolabelling a range of peptides and proteins with [(18) F]fluoroacetaldehyde analogous to other aldehyde-bearing prosthetic groups, yet automation of the method provides reproducibility thereby aiding translation to Good Manufacturing Practice manufacture and the transformation from pre-clinical to clinical production.

  20. In-Depth Characterization of N-Linked Oligosaccharides Using Fluoride-Mediated Negative Ion Microfluidic Chip LC-MS

    PubMed Central

    Ni, Wenqin; Bones, Jonathan; Karger, Barry L.

    2013-01-01

    Characterization of N-glycans by liquid chromatography-positive electrospray ionization (ESI) tandem mass spectrometry (LC-MS/MS) using a microfluidic chip packed with porous graphitized carbon (PGC) represents a rapidly developing area in oligosaccharide analysis. Positive ion ESI-MS generates B/Y-type glycosidic fragment ions under collisional induced dissociation (CID). Although these ions facilitate glycan sequencing, they provide little information on linkage and positional isomers. Isomer identification in these cases is by retention on the PGC stationary phase where the specific structural isomers can, in principle, be separated. In this paper, we broaden the applicability of the PGC microfluidic chip/MS platform by implementing fluoride-mediated negative ESI-MS. Ammonium fluoride, added to the mobile phase, aids in the formation of pseudomolecular oligosaccharide anions due to the ability of fluoride to abstract a proton from the glycan structure. The negative charge results in the generation of C-type glycosidic fragments, highly informative A-type cross ring fragment ions and additional gas phase ion reaction products (e.g., D- and E-type ions), which, when combined, lead to in-depth oligosaccharide characterization, including linkage and positional isomers. Due to the separation of anomers by the PGC phase, comparison of oligosaccharides with an intact reducing terminus to their corresponding alditols was performed, revealing a more sensitive MS and, especially, MS/MS response from the glycans with a free reducing end. Fluoride also ensured recovery of charged oligosaccharides from the PGC stationary phase. Application to the characterization of N-glycans released from polyclonal human and murine serum IgG is presented to demonstrate the effectiveness of the chip/negative ESI approach. PMID:23398125

  1. Staging and Functional Characterization of Pheochromocytoma and Paraganglioma by 18F-Fluorodeoxyglucose (18F-FDG) Positron Emission Tomography

    PubMed Central

    Timmers, Henri J. L. M.; Chen, Clara C.; Carrasquillo, Jorge A.; Whatley, Millie; Ling, Alexander; Eisenhofer, Graeme; King, Kathryn S.; Rao, Jyotsna U.; Wesley, Robert A.; Adams, Karen T.

    2012-01-01

    Background Pheochromocytomas and paragangliomas (PPGLs) are rare tumors of the adrenal medulla and extra-adrenal sympathetic chromaffin tissues; their anatomical and functional imaging are critical to guiding treatment decisions. This study aimed to compare the sensitivity and specificity of 18F-fluorodeoxyglucose positron emission tomography with computed tomography (18F-FDG PET/CT) for tumor localization and staging of PPGLs with that of conventional imaging by [123I]-metaiodobenzylguanidine single photon emission CT (123I-MIBG SPECT), CT, and magnetic resonance imaging (MRI). Methods A total of 216 patients (106 men, 110 women, aged 45.2 ± 14.9 years) with suspected PPGL underwent CT or MRI, 18F-FDG PET/CT, and 123I-MIBG SPECT/CT. Sensitivity and specificity were measured as endpoints and compared by the McNemar test, using two-sided P values only. Results Sixty (28%) of patients had nonmetastatic PPGL, 95 (44%) had metastatic PPGL, and 61 (28%) were PPGL negative. For nonmetastatic tumors, the sensitivity of 18F-FDG was similar to that of 123I-MIBG but less than that of CT/MRI (sensitivity of 18F-FDG = 76.8%; of 123I-MIBG = 75.0%; of CT/MRI = 95.7%; 18F-FDG vs 123I-MIBG: difference = 1.8%, 95% confidence interval [CI] = −14.8% to 14.8%, P = .210; 18F-FDG vs CT/MRI: difference = 18.9%, 95% CI = 9.4% to 28.3%, P < .001). The specificity was 90.2% for 18F-FDG, 91.8% for 123I-MIBG, and 90.2% for CT/MRI. 18F-FDG uptake was higher in succinate dehydrogenase complex– and von Hippel–Lindau syndrome–related tumors than in multiple endocrine neoplasia type 2 (MEN2) related tumors. For metastases, sensitivity was greater for 18F-FDG and CT/MRI than for 123I-MIBG (sensitivity of 18F-FDG = 82.5%; of 123I-MIBG = 50.0%; of CT/MRI = 74.4%; 18F-FDG vs 123I-MIBG: difference = 32.5%, 95% CI = 22.3% to 42.5%, P < .001; CT/MRI vs 123I-MIBG: difference = 24.4%, 95% CI = 11.3% to 31.6%, P < .001). For bone metastases, 18F-FDG was more sensitive than CT/MRI (sensitivity of 18

  2. Synthesis of [18F]arenes via the copper-mediated [18F]fluorination of boronic acids

    DOE PAGES

    Mossine, Andrew V.; Brooks, Allen F.; Makaravage, Katarina J.; ...

    2015-11-14

    Here, a copper-mediated radiofluorination of aryl- and vinylboronic acids with K18F is described. This method exhibits high functional group tolerance and is effective for the radiofluorination of a range of electron-deficient, -neutral, and -rich aryl-, heteroaryl-, and vinylboronic acids. This method has been applied to the synthesis of [18F]FPEB, a PET radiotracer for quantifying metabotropic glutamate 5 receptors.

  3. A novel facile method of labeling octreotide with 18F-fluorine

    PubMed Central

    Laverman, Peter; McBride, William J; Sharkey, Robert M; Eek, Annemarie; Joosten, Lieke; Oyen, Wim JG; Goldenberg, David M; Boerman, Otto C

    2010-01-01

    Several methods have been developed to label peptides with fluorine-18. However, in general these are laborious and require a multistep synthesis. We present a facile method based on the chelation of [18F]aluminum fluoride (“Al18F”) by NOTA (1,4,7-triazacyclononane-1,4,7-triacetic acid). The method is characterized by labeling NOTA-octreotide (IMP466) with 18F. Methods Octreotide was conjugated with the NOTA chelate and was labeled with 18F in a two-step, one-pot method. The labeling procedure was optimized with regard to the labeling buffer, peptide, and aluminum concentration. Radiochemical yield, specific activity, in vitro stability, and receptor affinity were determined. Biodistribution of 18F-IMP466 was studied in AR42J tumor-bearing mice and compared to that of 68Ga-labeled IMP466. In addition, microPET/CT images were acquired. Results IMP466 was labeled with “Al18F” in a single step with 50% yield. The labeled product was purified by HPLC to remove unbound “Al18F” and unlabeled peptide. The radiolabeling, including purification, was performed in 45 min. The specific activity was 45,000 GBq/mmol and the peptide was stable in serum for 4 h at 37° C. Labeling was performed at pH 4.1 in sodium citrate, sodium acetate, HEPES and MES buffer and was optimal in sodium acetate buffer. The apparent IC50 of the 19F-labeled IMP466 determined on AR42J cells was 3.6 nM. Biodistribution studies at 2 h p.i. showed a high tumor uptake of 18F-IMP466 (28.3 ± 5.2 %ID/g, tumor-to-blood ratio: 300 ± 90), which could be blocked by an excess of unlabeled peptide (8.6 ± 0.7%ID/g), indicating that the accumulation in the tumor was receptor-mediated. Biodistribution of 68Ga-IMP466 was similar to that of 18F-IMP466. 18F-IMP466 was stable in vivo, since bone uptake was only 0.4 ± 0.2 %ID/g, whereas free “Al18F” accumulated rapidly in the bone (36.9 ± 5.0 %ID/g at 2 h p.i.). MicroPET/CT scans showed excellent tumor delineation and high preferential accumulation in

  4. Evaluation of Prostate Cancer Bone Metastases with 18F-NaF and 18F-Fluorocholine PET/CT.

    PubMed

    Beheshti, Mohsen; Rezaee, Alireza; Geinitz, Hans; Loidl, Wolfgang; Pirich, Christian; Langsteger, Werner

    2016-10-01

    (18)F-fluorocholine is a specific promising agent for imaging tumor cell proliferation, particularly in prostate cancer, using PET/CT. It is a beneficial tool in the early detection of marrow-based metastases because it excludes distant metastases and evaluates the response to hormone therapy. In addition, (18)F-fluorocholine has the potential to differentiate between degenerative and malignant osseous abnormalities because degenerative changes are not choline-avid; however, the agent may accumulate in recent traumatic bony lesions. On the other hand, (18)F-NaF PET/CT can indicate increased bone turnover and is generally used in the assessment of primary and secondary osseous malignancies, the evaluation of response to treatment, and the clarification of abnormalities on other imaging modalities or clinical data. (18)F-NaF PET/CT is a highly sensitive method in the evaluation of bone metastases from prostate cancer, but it has problematic specificity, mainly because of tracer accumulation in degenerative and inflammatory bone diseases. In summary, (18)F-NaF PET/CT is a highly sensitive method, but (18)F-fluorocholine PET/CT can detect early bone marrow metastases and provide greater specificity in the detection of bone metastases in patients with prostate cancer. However, the difference seems not to be significant.

  5. Practical Aspects of 18F-FDG PET When Receiving 18F-FDG from a Distant Supplier.

    PubMed

    Ducharme, Jaylene; Goertzen, Andrew L; Patterson, Judy; Demeter, Sandor

    2009-09-01

    With PET becoming more widely used, there is an increase in the number of imaging centers being forced to rely on distant suppliers of (18)F-FDG. Because of the large distances between major urban centers, this is particularly true for PET centers in Canada. Our PET center, located in Winnipeg, Manitoba, Canada, currently purchases (18)F-FDG from a commercial vendor located more than 1,000 km from Winnipeg, necessitating transport by commercial airline cargo. This dependence on air transport and a distant supplier creates a situation in which our (18)F-FDG supply is less reliable than it would be with onsite production. In this article, we offer insight into the obstacles we have encountered in imaging with a distant supplier of (18)F-FDG and the solutions we have implemented to minimize the disruption to our patients and maximize the number of scans performed each year. The development of contingency plans and protocols designed to suit our operating environment has allowed us to increase the number of patient scans obtained from 659 in year 1 to 993 in year 3, an increase of 51%, despite an increase in our actual number of scan days of only 24%. (18)F-FDG injection timetables are presented for a variety of scenarios including normal delivery, low shipped activity, and delayed delivery. Through the careful establishment of contingency protocols and management of (18)F-FDG shipments, patient throughput can be increased and disruptions minimized.

  6. [Effect of fluoride ion on corrosion of two dental titanium alloys].

    PubMed

    Cao, Bo-Wei; Chen, Lei

    2010-06-01

    To investigate the effect of fluoride concentration on the corrosion behavior of Ti-12Zr alloy and Ti-6Al-4V alloy in a simulated oral environment. Each specimen was put into the acidic artificial saliva (pH = 4.0) with different NaF concentration (0%, 0.05%, 0.1%, 0.2%) and electrochemical experiment was carried out. Then the surface microstructure and compositions of specimen were analyzed by scanning electron microscope (SEM) after immersed in the test solution with constant temperature. The corrosion potential (E(corr)) and polarization resistance (R(p)) values of titanium alloy decreased with the increasing of NaF concentration, while the corrosion current density (I(corr)) values increased with the increasing of NaF concentration in acidic artificial saliva. The E(corr), R(p) and I(corr) values of titanium alloy changed significantly when the NaF concentration was over 0.1% (P < 0.05). The R, between Ti-12Zr alloy and Ti-6Al-4V alloy had a statistically significant difference, and the R(p) of Ti-12Zr alloy was higher than that of Ti-6Al-4V alloy when the NaF concentration was 0.2% (P < 0.05). The fluoride ions have a negative influence on the corrosion resistance of Ti-12Zr alloy and Ti-6Al-4V alloy, especially in the acidic artificial saliva which contained over 0.1% NaF.

  7. Fabrication of an electrochemical sensor based on spiropyran for sensitive and selective detection of fluoride ion.

    PubMed

    Tao, Jia; Zhao, Peng; Li, Yinhui; Zhao, Wenjie; Xiao, Yue; Yang, Ronghua

    2016-04-28

    In the past decades, numerous electrochemical sensors based on exogenous electroactive substance have been reported. Due to non-specific interaction between the redox mediator and the target, the instability caused by false signal may not be avoided. To address this issue, in this paper, a new electrochemical sensor based on spiropyran skeleton, namely SPOSi, was designed for specific electrochemical response to fluoride ions (F(-)). The breakage of Si-O induced by F(-) based on the specific nucleophilic substitution reaction between F(-) and silica would directly produce a hydroquinone structure for electrochemical signal generation. To improve the sensitivity, SPOSi probe was assembled on the single-walled carbon nanotubes (SWCNTs) modified glassy carbon electrode (GCE) through the π-π conjugating interaction. This electrode was successfully applied to monitor F(-) with a detection limit of 8.3 × 10(-8) M. Compared with the conventional F(-) ion selected electrode (ISE) which utilized noncovalent interaction, this method displays higher stability and a comparable sensitivity in the urine samples.

  8. Electrospun montmorillonite modified poly(vinylidene fluoride) nanocomposite separators for lithium-ion batteries

    SciTech Connect

    Fang, Changjiang; Yang, Shuli; Zhao, Xinfei; Du, Pingfan; Xiong, Jie

    2016-07-15

    Highlights: • Composite separators of PVDF and MMT for lithium-ion batteries were electrospun. • Thermal dimensional stability and tensile property of composite separators get improved. • Presence of montmorillonite promotes electrical properties of PVDF fibrous separators. • Batteries consisting of PVDF/MMT-5% separator achieve the best performance. - Abstract: Composite separators of poly(vinylidene fluoride) (PVDF) with different contents of montmorillonite (MMT) for Li-ion batteries have been fabricated by electrospinning. The morphology, function group, crystallinity, and mechanical properties of membranes were investigated by scanning electron microscope (SEM), Fourier Transform infrared spectra (FT-IR), differential scanning calorimetry (DSC), and tensile test, respectively. Interlayer spacing of MMT in polymer was characterized by X-ray diffraction (XRD). In addition, the results of electrochemical measurements suggest that PVDF/MMT-5% composite membrane has maximum ionic conductivity of 4.2 mS cm{sup −1}, minimum interfacial resistance of 97 Ω, and excellent electrochemical stability. The cell comprising PVDF/MMT-5% composite membrane shows higher capacity and more stable cycle performance than the one using commercial Celgard PP membrane.

  9. Evaluation of 18F-FDG uptake and arterial wall calcifications using 18F-FDG PET/CT.

    PubMed

    Ben-Haim, Simona; Kupzov, Ela; Tamir, Ada; Israel, Ora

    2004-11-01

    Glucose metabolic activity expressed as (18)F-FDG uptake may be increased in active atherosclerotic plaque. Calcium depositions are often increased in mature atherosclerotic plaque. The purpose of the present study was to assess the patterns of vascular-wall (18)F-FDG uptake and CT calcifications using combined PET/CT. One hundred twenty-two consecutive patients over the age of 50 (47 women and 75 men; mean age, 66 +/- 9 y) undergoing whole-body (18)F-FDG PET/CT for tumor assessment were retrospectively evaluated. PET, CT, and PET/CT slices were generated for review. Abnormal vascular findings in major arteries in the chest and abdomen were categorized as PET positive (PET+), PET negative (PET-), CT positive (CT+), or CT negative (CT-). The topographic relationship between increased vascular-wall (18)F-FDG uptake on PET and the presence of calcifications on CT was assessed on PET/CT fused images, with abnormal sites further classified as PET+/CT+, PET+/CT-, or PET-/CT+. The presence of CT calcifications and increased vascular-wall (18)F-FDG uptake was correlated with age, sex, presence of cardiovascular risk factors, and cardiovascular disease. Abnormal findings were identified at 349 sites. CT calcifications (CT+) were observed at 320 sites (92%) of 100 patients (82%), more commonly in men (P < 0.03), in older patients (P < 0.0001), in patients with hypertension (P < 0.003) or hyperlipidemia (P < 0.04), and in smokers (P < 0.008). Increased vascular-wall (18)F-FDG uptake (PET+) was observed at 52 sites (15%) of 38 patients (31%), more commonly in men (P < 0.02), in older patients (P < 0.0001), and in patients with hypertension (P < 0.02), and was borderline in patients with cardiovascular disease (P = 0.057). PET+ and CT+ findings correlated in 12 patients, a PET+/CT- pattern was found in 18 patients, and 8 patients had increased vascular-wall (18)F-FDG uptake in sites with and without calcifications (PET+/CT+, CT-). Twenty-two patients (18%) had a PET

  10. [[18F]-FDG imaging in apparently isolated pleural lesions].

    PubMed

    Balogova, S; Grahek, D; Kerrou, K; Montravers, F; Younsi, N; Aide, N; Jacob, T; Talbot, J-N

    2003-11-01

    While a great deal of work has been performed concerning the impact of [18F]-FDG imaging in isolated lung lesion(s), there are still very few data about its role in case of isolated pleural lesions. The aim of this preliminary study was to shed some light on the utility of [18F]-FDG imaging, using PET or CDET detection, in this context. Sixteen patients referred for apparently isolated pleural lesions were included in this study, since their 22 [18F]-FDG examinations were evaluable on bases of histology (9 cases), rapid disease progression (4 cases) or a follow-up period of more than 6 months (9 cases). Twelve [18F]-FDG examinations were performed with a dedicated PET machine (C-PET, Adac) and ten with a coincidence detection gamma camera (Irix, Picker). The precise clinical settings were the following: characterization of pleural masses or search for the unknown primary tumor in case of adenocarcinoma (6 cases), staging of a mesothelioma (5 cases), suspicion of recurrence and/or residual lesions (11 cases). The malignant pleural lesions took up [18F]-FDG in all cases. There was one false positive result due to an inflammatory lesion. False negative results for the detection of lymph node invasion occurred in three patients and were in relation with their infracentimetric size and the difficulty to distinguish on [18F]-FDG images mediastinal lymph nodes from widespread pleural and pulmonary extension of cancer. A change in patient management resulted from the [18F]-FDG examination in 4 patients (25%) and the course confirmed that the change was correct. Unknown lesions or active lesions wrongly considered residual that could have modified the management were discovered in 3 other patients. This study highlights the fact that [18F]-FDG imaging has an impact on the management of patients with solitary pleural lesions and can detect recurrences, in some cases even more accurately than invasive procedures with histology. In our limited experience, the lack of

  11. Cationic boranes for the complexation of fluoride ions in water below the 4 ppm maximum contaminant level.

    PubMed

    Kim, Youngmin; Gabbaï, François P

    2009-03-11

    In search of a molecular receptor that could bind fluoride ions in water below the maximum contaminant level of 4 ppm set by the Environmental Protection Agency (EPA), we have investigated the water stability and fluoride binding properties of a series of phosphonium boranes of general formula [p-(Mes(2)B)C(6)H(4)(PPh(2)R)](+) with R = Me ([1](+)), Et ([2](+)), n-Pr ([3](+)), and Ph ([4](+)). These phosphonium boranes are water stable and react reversibly with water to form the corresponding zwitterionic hydroxide complexes of general formula p-(Mes(2)(HO)B)C(6)H(4)(PPh(2)R). They also react with fluoride ions to form the corresponding zwitterionic fluoride complexes of general formula p-(Mes(2)(F)B)C(6)H(4)(PPh(2)R). Spectrophotometric acid-base titrations carried out in H(2)O/MeOH (9:1 vol.) afford pK(R+) values of 7.3(+/-0.07) for [1](+), 6.92(+/-0.1) for [2](+), 6.59(+/-0.08) for [3](+), and 6.08(+/-0.09) for [4](+), thereby indicating that the Lewis acidity of the cationic boranes increases in following order: [1](+) < [2](+) < [3](+) < [4](+). In agreement with this observation, fluoride titration experiments in H(2)O/MeOH (9:1 vol.) show that the fluoride binding constants (K = 840(+/-50) M(-1) for [1](+), 2500(+/-200) M(-1) for [2](+), 4000(+/-300) M(-1) for [3](+), and 10 500(+/-1000) M(-1) for [4](+)) increase in the same order. These results show that the Lewis acidity of the cationic boranes increases with their hydrophobicity. The resulting Lewis acidity increase is substantial and exceeds 1 order of magnitude on going from [1](+) to [4](+). In turn, [4](+) is sufficiently fluorophilic to bind fluoride ions below the EPA contaminant level in pure water. These results indicate that phosphonium boranes related to [4](+) could be used as molecular recognition units in chemosensors for drinking water analysis.

  12. Effect of layered double hydroxide intercalated with fluoride ions on the physical, biological and release properties of a dental composite resin.

    PubMed

    Tammaro, Loredana; Vittoria, Vittoria; Calarco, Anna; Petillo, Orsolina; Riccitiello, Francesco; Peluso, Gianfranco

    2014-01-01

    The aim of this work was the preparation of a new fluoride-releasing dental material characterized by a release of fluoride relatively constant over time without any initial toxic burst effect. This type of delivery is obtained by a matrix controlled elution and elicits the beneficial effect of a low amount of fluoride on human dental pulp stem cells (hDPSCs) towards mature phenotype. The modified hydrotalcite intercalated with fluoride ions (LDH-F), used as filler, was prepared via ion exchange procedure and characterized by X-ray diffraction and FT-IR spectroscopy. The LDH-F inorganic particles (0.7, 5, 10, 20wt.%) were mixed with a photo-activated Bis-GMA/TEGDMA (45/55wt/wt) matrix and novel visible-light cured composites were prepared. The dynamic thermo-mechanical properties were determined by dynamic mechanical analyzer. The release of fluoride ions in physiological solution was determined using a ionometer. Total DNA content was measured by a PicoGreen dsDNA quantification kit to assess the proliferation rate of hDPSCs. Alkaline phosphatase activity (ALP) was measured in presence of fluoride resins. Incorporation of even small mass fractions (e.g. 0.7 and 5wt.%) of the fluoride LDH in Bis-GMA/TEGDMA dental resin significantly improved the mechanical properties of the pristine resin, in particular at 37°C. The observed reinforcement increases on increasing the filler concentration. The release of fluoride ions resulted very slow, lasting months. ALP activity gradually increased for 28 days in hDPSCs cell grown, demonstrating that low concentrations of fluoride contributed to the cell differentiation. The prepared composites containing different amount of hydrotalcite filler showed improved mechanical properties, slow fluoride release and promoted hDPSCs cell proliferation and cell differentiation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Structural changes of conversion metal fluoride cathodes in lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Sina, Mahsa

    Currently, cathode materials for Li-ion batteries are based on intercalation processes where, during charge and discharge processes, Li intercalates into the crystal lattice while maintaining the host crystal structure. More recently, new cathode materials have been introduced based on conversion reactions involving phase transformation and complete reduction of the host transition metal. In addition, conversion reactions involve two or more Li ions with a resulting much higher capacity than obtainable for intercalation materials. However, mechanism of phase transformation and cycling reversibility are at present still poorly understood. In this study transmission electron microscopy (TEM) techniques including selected area electron diffraction (SAED) pattern, annular dark field (ADF) STEM image, and electron energy loss spectroscopy (EELS) with nanoscale spatial resolution were used to study the phase evolution and structural changes of iron fluorides (FeFe2, FeO0.7F 1.3, FeF3) after various discharge/charge cycles. Additionally, the changes of the Fe valence states upon cycling were determined using EELS by measuring the L3/L2 intensity ratio of Fe-L edge. The structural transformations of FeO0.7F1.3 during the first lithiation show that litiahation contains two regions. The first region, lithiation is an intercalation reaction with reduction of Fe 3+ to Fe2+. The second region of lithiation involves a conversion reaction, with the formation of metallic Fe, LiF, and Li 0.7Fe2+0.5O0.7F0.3 (rocksalt type) phases. The first delithiation process follows a different conversion reaction path compared to the first lithiation reaction involving the formation an amorphous rutile-type phase along with with the rocksalt-type phase. Interestingly, upon full recharge (delithiated electrode), the measured average Fe valence state returns back to its initial value of Fe2.7+. The growth of a solid electrolyte interphase (SEI) layer formation at the electrode

  14. Radiation dosimetry of [(18)F]VAT in nonhuman primates.

    PubMed

    Karimi, Morvarid; Tu, Zhude; Yue, Xuyi; Zhang, Xiang; Jin, Hongjun; Perlmutter, Joel S; Laforest, Richard

    2015-12-01

    The objective of this study is to determine the radiation dosimetry of a novel radiotracer for vesicular acetylcholine transporter (-)-(1-((2R,3R)-8-(2-[(18)F]fluoro-ethoxy)-3-hydroxy-1,2,3,4-tetrahydronaphthalen-2-yl)piperidin-4-yl)(4-fluorophenyl)-methanone ([(18)F]VAT) based on PET imaging in nonhuman primates. [(18)F]VAT has potential for investigation of neurological disorders including Alzheimer's disease, Parkinson's disease, and dystonia. Three macaque fascicularis (two males, one female) received 185.4-198.3 MBq [(18)F]VAT prior to whole-body imaging in a MicroPET-F220 scanner. Time activity curves (TACs) were created from regions of interest (ROIs) that encompassed the entire small organs or samples with the highest activity within large organs. Organ residence times were calculated based on the TACs. We then used OLINDA/EXM 1.1 to calculate human radiation dose estimates based on scaled organ residence times. Measurements from directly sampled arterial blood yielded a residence time of 0.30 h in agreement with the residence time of 0.39 h calculated from a PET-generated time activity curve measured in the left ventricle. Organ dosimetry revealed the liver as the critical organ (51.1 and 65.4 μGy/MBq) and an effective dose of 16 and 19 μSv/MBq for male and female, respectively. The macaque biodistribution data showed high retention of [(18)F]VAT in the liver consistent with hepatobiliary clearance. These dosimetry data support that relatively safe doses of [(18)F]VAT can be administered to obtain imaging in humans.

  15. Reproducibility of 18F-FDG and 3'-deoxy-3'-18F-fluorothymidine PET tumor volume measurements.

    PubMed

    Hatt, Mathieu; Cheze-Le Rest, Catherine; Aboagye, Eric O; Kenny, Laura M; Rosso, Lula; Turkheimer, Federico E; Albarghach, Nidal M; Metges, Jean-Philippe; Pradier, Olivier; Visvikis, Dimitris

    2010-09-01

    The objective of this study was to establish the repeatability and reproducibility limits of several volume-related PET image-derived indices-namely tumor volume (TV), mean standardized uptake value, total glycolytic volume (TGV), and total proliferative volume (TPV)-relative to those of maximum standardized uptake value (SUV(max)), commonly used in clinical practice. Fixed and adaptive thresholding, fuzzy C-means, and fuzzy locally adaptive Bayesian methodology were considered for TV delineation. Double-baseline (18)F-FDG (17 lesions, 14 esophageal cancer patients) and 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) (12 lesions, 9 breast cancer patients) PET scans, acquired at a mean interval of 4 d and before any treatment, were used for reproducibility evaluation. The repeatability of each method was evaluated for the same datasets and compared with manual delineation. A negligible variability of less than 5% was measured for all segmentation approaches in comparison to manual delineation (5%-35%). SUV(max) reproducibility levels were similar to others previously reported, with a mean percentage difference of 1.8% +/- 16.7% and -0.9% +/- 14.9% for the (18)F-FDG and (18)F-FLT lesions, respectively. The best TV, TGV, and TPV reproducibility limits ranged from -21% to 31% and -30% to 37% for (18)F-FDG and (18)F-FLT images, respectively, whereas the worst reproducibility limits ranged from -90% to 73% and -68% to 52%, respectively. The reproducibility of estimating TV, mean standardized uptake value, and derived TGV and TPV was found to vary among segmentation algorithms. Some differences between (18)F-FDG and (18)F-FLT scans were observed, mainly because of differences in overall image quality. The smaller reproducibility limits for volume-derived image indices were similar to those for SUV(max), suggesting that the use of appropriate delineation tools should allow the determination of tumor functional volumes in PET images in a repeatable and reproducible fashion.

  16. No-carrier-added (18F)-N-methylspiroperidol

    DOEpatents

    Shiue, Chyng-Yann; Fowler, Joanna S.; Wolf, Alfred P.

    1993-07-06

    There is disclosed a radioligand labeled with a positron emitting radionuclide suitable for dynamic study in living humans with positron emission transaxial tomography. [.sup.18 F]-N-methylspiroperidol, exhibiting extremely high affinity for the dopamine receptors, provides enhanced uptake and retention in the brain concomitant with reduced radiation burden. These characteristics all combine to provide [.sup.18 F]-N-methylspiroperidol as a radioligand superior to known radioligands for mapping dopamine receptors in normal and disease states in the living brain. Additionally, a new synthetic procedure for this material is disclosed.

  17. No-carrier-added (18F)-N-methylspiroperidol

    DOEpatents

    Shiue, Chyng-Yann; Fowler, Joanna S.; Wolf, Alfred P.

    1993-01-01

    There is disclosed a radioligand labeled with a positron emitting radionuclide suitable for dynamic study in living humans with positron emission transaxial tomography. [.sup.18 F]-N-methylspiroperidol, exhibiting extremely high affinity for the dopamine receptors, provides enhanced uptake and retention in the brain concomitant with reduced radiation burden. These characteristics all combine to provide [.sup.18 F]-N-methylspiroperidol as a radioligand superior to known radioligands for mapping dopamine receptors in normal and disease states in the living brain. Additionally, a new synthetic procedure for this material is disclosed.

  18. [18F]haloperidol binding in baboon brain in vivo.

    PubMed

    Yousef, K A; Fowler, J S; Volkow, N D; Dewey, S L; Shea, C; Schlyer, D J; Gatley, S J; Logan, J; Wolf, A P

    1996-01-01

    The binding of [18F]haloperidol to dopamine D2 and to sigma recognition sites in baboon brain was examined using positron emission tomography (PET). Studies were performed at baseline and after treatment with either haloperidol (to evaluate saturability), (+)-butaclamol (which has specificity for dopamine D2 receptors) or (-)-butaclamol (which has specificity for sigma sites). Binding was widespread. Treatment with (-)-butaclamol had no effect, whereas (+)-butaclamol selectively reduced the uptake in striatum. Haloperidol increased the clearance rate from all brain regions. These results indicate that the binding profile of [18F]haloperidol does not permit the selective examination of either dopamine D2 or sigma sites using PET.

  19. Highly selective visual monitoring of hazardous fluoride ion in aqueous media using thiobarbituric-capped gold nanoparticles.

    PubMed

    Boken, Jyoti; Thatai, Sheenam; Khurana, Parul; Prasad, Surendra; Kumar, Dinesh

    2015-01-01

    The rapid, selective and sensitive measurement and monitoring of hazardous materials as analytes are the central themes in the development of any successful analytical technique. With this aim, we have synthesized the thiobarbituric-capped gold nanoparticles (TBA-capped Au NPs) involving chemical reduction of HAuCl4 using 2-thiobarbituric acid (TBA) as a reducing and capping agent. The morphology of the TBA-capped Au NPs was confirmed using transmission electron microscope images. For the first time this article reports that the developed TAB-capped Au NPs displays selective, ultrafast and sensitive colorimetric detection of fluoride ion in aqueous samples. The detection of fluoride ion was confirmed by the disappearance of the localized surface plasmon resonance (LSPR) band at 554 nm using UV-vis spectroscopy. The interaction of F(-) with TBA-capped Au NPs in aqueous solution has also been confirmed by Raman and FTIR spectroscopy. One of the most exciting accomplishments is the visual detection limit for fluoride ion has been found to be 10 mM at commonly acceptable water pH range 7-8. The whole detection procedure takes not more than 40s with excellent selectivity providing sample throughput of more than 60 per hour. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Mechanism of Electrophilic Fluorination with Pd(IV): Fluoride Capture and Subsequent Oxidative Fluoride Transfer†, ‡

    PubMed Central

    Brandt, Jochen R.; Lee, Eunsung; Boursalian, Gregory B.

    2013-01-01

    Electrophilic fluorinating reagents derived from fluoride are desirable for the synthesis of 18F-labeled molecules for positron emission tomography (PET). Here, we study the mechanism by which a Pd(IV)-complex captures fluoride and subsequently transfers it to nucleophiles. The intermediate Pd(IV)-F is formed with high rates even at the nano- to micromolar fluoride concentrations typical for radiosyntheses with 18F due to fast formation of an outer-sphere complex between fluoride and Pd(IV). The subsequent fluorine transfer from the Pd(IV)-F complex is proposed to proceed through an unusual SET/fluoride transfer/SET mechanism. The findings detailed in this manuscript provide a theoretical foundation suitable for addressing a more general approach for electrophilic fluorination with high specific activity 18F PET imaging. PMID:24376910

  1. A preliminary investigation of lithogenic and anthropogenic influence over fluoride ion chemistry in the groundwater of the southern coastal city, Tamilnadu, India.

    PubMed

    Selvam, S

    2015-03-01

    A total of 72 groundwater samples were collected from open wells and boreholes during pre- and post-monsoon periods in Tuticorin. Samples were analyzed for physicochemical properties, major cations, and anions in the laboratory using the standard methods given by the American Public Health Association. The fluoride concentration was analyzed in the laboratory using Metrohm 861 advanced compact ion chromatography. The geographic information system-based spatial distribution map of different major elements has been prepared using ArcGIS 9.3. The fluoride concentration ranges between 0.16 mg/l and 4.8 mg/l during pre-monsoon and 0.2-3.2 mg/l during post-monsoon. Alkaline pH, low calcium concentrations, high groundwater temperatures, and semiarid climatic conditions of the study area may cause elevated fluoride concentrations in groundwater, by increasing the solubility of fluoride-bearing formations (fluoride). Linear trend analysis on seasonal and annual basis clearly depicted that fluoride pollution in the study area is increasing significantly. Fluoride concentrations showed positive correlations with those of Na(+) and HCO3 (-) and negative correlations with Ca(2+) and Mg(2+). The alkaline waters were saturated with calcite in spite of the low Ca(2+) concentrations. Northwestern parts of the study area are inherently enriched with fluorides threatening several ecosystems. The saturation index indicates that dissolution and precipitation contribute fluoride dissolution along with mixing apart from anthropogenic activities.

  2. Radiosynthesis and 'click' conjugation of ethynyl-4-[(18)F]fluorobenzene--an improved [(18)F]synthon for indirect radiolabeling.

    PubMed

    Roberts, Maxine P; Pham, Tien Q; Doan, John; Jiang, Cathy D; Hambley, Trevor W; Greguric, Ivan; Fraser, Benjamin H

    2015-01-01

    Reproducible methods for [(18)F]radiolabeling of biological vectors are essential for the development of new [(18)F]radiopharmaceuticals. Molecules such as carbohydrates, peptides and proteins are challenging substrates that often require multi-step indirect radiolabeling methods. With the goal of developing more robust, time saving, and less expensive procedures for indirect [(18)F]radiolabeling of such molecules, our group has synthesized ethynyl-4-[(18)F]fluorobenzene ([(18)F]2, [(18)F]EYFB) in a single step (14 ± 2% non-decay corrected radiochemical yield (ndc RCY)) from a readily synthesized, shelf stable, inexpensive precursor. The alkyne-functionalized synthon [(18)F]2 was then conjugated to two azido-functionalized vector molecules via CuAAC reactions. The first 'proof of principle' conjugation of [(18)F]2 to 1-azido-1-deoxy-β-D-glucopyranoside (3) gave the desired radiolabeled product [(18)F]4 in excellent radiochemical yield (76 ± 4% ndc RCY (11% overall)). As a second example, the conjugation of [(18)F]2 to matrix-metalloproteinase inhibitor (5), which has potential in tumor imaging, gave the radiolabeled product [(18)F]6 in very good radiochemical yield (56 ± 12% ndc RCY (8% overall)). Total preparation time for [(18)F]4 and [(18)F]6 including [(18)F]F(-) drying, two-step reaction (nucleophilic substitution and CuAAC conjugation), two HPLC purifications, and two solid phase extractions did not exceed 70 min. The radiochemical purity of synthon [(18)F]2 and the conjugated products, [(18)F]4 and [(18)F]6, were all greater than 98%. The specific activities of [(18)F]2 and [(18)F]6 were low, 5.97 and 0.17 MBq nmol(-1), respectively.

  3. Synthesis, in vitro and in vivo evaluation of 3β-[18F]fluorocholic acid for the detection of drug-induced cholestasis in mice

    PubMed Central

    Neyt, Sara; Kersemans, Ken; Verhoeven, Jeroen; Devisscher, Lindsey; Van Vlierberghe, Hans; Vanhove, Christian; De Vos, Filip

    2017-01-01

    Introduction Drug-induced cholestasis is a liver disorder that might be caused by interference of drugs with the hepatobiliary bile acid transporters. It is important to identify this interference early on in drug development. In this work, Positron Emission Tomography (PET)-imaging with a 18F labeled bile acid analogue was introduced to detect disturbed hepatobiliary transport of bile acids. Methods 3β-[18F]fluorocholic acid ([18F]FCA) was prepared by nucleophilic substitution of a mesylated precursor with [18F]fluoride, followed by deprotection with sodium hydroxide. Transport of [18F]FCA was assessed in vitro using CHO-NTCP, HEK-OATP1B1, HEK-OATP1B3 transfected cells and BSEP & MRP2 membrane vesicles. Investigation of [18F]FCA metabolites was performed with primary mouse hepatocytes. Hepatobiliary transport of [18F]FCA was evaluated in vivo in wild-type, rifampicin and bosentan pretreated FVB-mice by dynamic μPET scanning. Results Radiosynthesis of [18F]FCA was achieved in a moderate radiochemical yield (8.11 ± 1.94%; non-decay corrected; n = 10) and high radiochemical purity (>99%). FCA was transported by the basolateral bile acid uptake transporters NTCP, OATP1B1 and OATP1B3. For canalicular efflux, BSEP and MRP2 are the relevant bile acid transporters. [18F]FCA was found to be metabolically stable. In vivo, [18F]FCA showed fast hepatic uptake (4.5 ± 0.5 min to reach 71.8 ± 1.2% maximum % ID) and subsequent efflux to the gallbladder and intestines (93.3 ± 6.0% ID after 1 hour). Hepatobiliary transport of [18F]FCA was significantly inhibited by both rifampicin and bosentan. Conclusion A 18F labeled bile acid analogue, [18F]FCA, has been developed that shows transport by NTCP, OATP, MRP2 and BSEP. [18F]FCA can be used as a probe to monitor disturbed hepatobiliary transport in vivo and accumulation of bile acids in blood and liver during drug development. PMID:28273180

  4. In vitro reconstituted biotransformation of 4-fluorothreonine from fluoride ion: application of the fluorinase.

    PubMed

    Deng, Hai; Cross, Stuart M; McGlinchey, Ryan P; Hamilton, John T G; O'Hagan, David

    2008-12-22

    In this paper, we report that fluoride ion is converted to the amino acid/antibiotic 4-fluorothreonine 2 in a biotransformation involving five (steps a-e) overexpressed enzymes. The biotransformation validates the biosynthetic pathway to 4-fluorothreonine in the bacterium Streptomyces cattleya (Schaffrath et al., 2002). To achieve an in vitro biotransformation, the fluorinase and the purine nucleoside phosphorylase (PNP) enzymes (steps a and b), which are coded for by the flA and flB genes of the fluorometabolite gene cluster in S. cattleya, were overexpressed. Also, an isomerase gene product that can convert 5-FDRP 6 to 5-FDRibulP 7 (step c) was identified in S. cattleya, and the enzyme was overexpressed for the biotransformation. A fuculose aldolase gene from S. coelicolor was overexpressed in E. coli and was used as a surrogate aldolase (step d) in these experiments. To complete the complement of enzymes, an ORF coding the PLP-dependent transaldolase, the final enzyme of the fluorometabolite pathway, was identified in genomic DNA by a reverse genetics approach, and the S. cattleya gene/enzyme was then overexpressed in S. lividans. This latter enzyme is an unusual PLP-dependent catalyst with some homology to both bacterial serine hydroxymethyl transferases (SHMT) and C5 sugar isomerases/epimerases. The biotransformation demonstrates the power of the fluorinase to initiate C-F bond formation for organo-fluorine synthesis.

  5. Photomodulation of fluoride ion binding through anion-π interactions using a photoswitchable azobenzene system

    PubMed Central

    Rananaware, Anushri; Samanta, Mousumi; Bhosale, Rajesh S.; Kobaisi, Mohammad Al; Roy, Biswajit; Bheemireddy, Varun; Bhosale, Sidhanath V.; Bandyopadhyay, Subhajit; Bhosale, Sheshanath V.

    2016-01-01

    The discovery of photoswitchable azobenzene-systems that undergo trans-to-cis photoisomerisation was a milestone in supramolecular chemistry. Such photoswitches have possible applications in data storage, stimuli responsive delivery systems, and molecular machines due to fast and selective switching. However, the light induced cis isomer of azobenzene is rather unstable and reverts thermally and photochemically to the thermodynamically stable trans configuration. We report, for the first time, controlled photoswitching of an azo-naphthalenediimide (azo-NDI) which can be achieved upon binding of fluoride ions through anion-π interaction. This NDI-F–NDI “sandwich” stabilises the cis configuration through the generation of an NDI•− radical anion, and a dianionic, NDI2− species that becomes unusually stable in the cis form. The sandwiched cis form reverts to the trans form only upon decomplexation of F−. A model pollutant was successfully degraded using the photogenerated NDI-F–NDI sandwich. This opens a wide range of applications in molecular and supramolecular nanotechnology. PMID:26953168

  6. New Developments in Chiral Cooperative Ion Pairing Organocatalysis by Means of Ammonium Oxyanions and Fluorides: From Protonation to Deprotonation Reactions.

    PubMed

    Legros, Fabien; Oudeyer, Sylvain; Levacher, Vincent

    2016-10-13

    This personal account summarizes our contribution to the ion pairing organocatalysis mainly by use of chiral quaternary or tertiary ammonium fluorides, aryloxides and carboxylates. Starting from an experimental observation, we were able to develop several approaches for the enantioselective protonation of silyl enolates and enol esters giving rise to chiral carbonyl compounds bearing a stereogenic center at the α-position. Moving from protonation to deprotonation reactions, chiral ammonium ion pair catalysts were successfully applied to several asymmetric transformations such as an Henry reaction or a direct vinylogous aldol reaction to cite a few. An outlook of further possible developments in this field of research will also be discussed.

  7. The influence of fluoride ions upon selected enzymes of protein metabolism in blood plasma of rabbits with hypercholesterolemia.

    PubMed

    Birkner, Ewa; Grucka-Mamczar, Ewa; Kasperczyk, Sławomir; Kasperczyk, Aleksandra; Stawiarska-Pieta, Barbara; Zalejska-Fiolka, Jolanta; Birkner, Beata

    2008-08-01

    Three-month studies were performed on 18 adult rabbits of New Zealand breed divided into three groups, with six animals in each: a control group on standard diet, a cholesterol group receiving 500 mg of cholesterol/100 g of feed per rabbit per 24 h (CH group), and a cholesterol + fluorine group (CH + F group) receiving 500 mg of cholesterol/100 g of feed per rabbit per 24 h and 3 mg of F(-)/kg of body weight per 24 h. The conducted studies proved that cholesterol in the applied dosage (500 mg cholesterol per rabbit per 24 h) has an atherogenic action. Fluoride ions administered together with a 500-mg cholesterol atherogenic diet inhibit the atheromatosic changes in the aorta. The concentration of plasma cholesterol was elevated in both study groups when compared to the control group but decreased in the CH + F group when compare to the CH group. The influence of fluoride ions has been examined upon the activity of alanine aminotransferase, aspartate aminotransferase, and glutamate dehydrogenase (GLDH) in the plasma in the liver of rabbits in the course of experimental hypercholesterolemia. Increase in the activity of study enzymes has been observed in the blood plasma, which may be due to damage occurring to hepatocytes of the animals examined (a statistically significant increase in the activity of GLDH in the plasma). In the liver, the inhibition of activity for all examined enzymes has been observed in the group of rabbits with hypercholesterolemia, which testifies the disturbances in protein metabolism in examined animals. The addition of sodium fluoride to the diet rich in cholesterol results in "removing the block" on those activities, which increase. We suppose that the permeability of the hepatocyte membrane was elevated, so the activities of examined enzymes increased in the plasma ("escape" to plasma). On the one hand, fluoride ions result in probable lesion of hepatocytes membranes; on the other hand, they inhibit the atheromatosic changes in the aorta.

  8. 17 CFR 270.18f-3 - Multiple class companies.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 3 2011-04-01 2011-04-01 false Multiple class companies. 270... (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.18f-3 Multiple class companies... registered open-end management investment company or series or class thereof established in accordance...

  9. 17 CFR 270.18f-3 - Multiple class companies.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 4 2014-04-01 2014-04-01 false Multiple class companies. 270... (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.18f-3 Multiple class companies... registered open-end management investment company or series or class thereof established in accordance...

  10. 17 CFR 270.18f-3 - Multiple class companies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Multiple class companies. 270... (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.18f-3 Multiple class companies... registered open-end management investment company or series or class thereof established in accordance...

  11. 17 CFR 270.18f-3 - Multiple class companies.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 3 2012-04-01 2012-04-01 false Multiple class companies. 270... (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.18f-3 Multiple class companies... registered open-end management investment company or series or class thereof established in accordance...

  12. 17 CFR 270.18f-3 - Multiple class companies.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 3 2013-04-01 2013-04-01 false Multiple class companies. 270... (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.18f-3 Multiple class companies... registered open-end management investment company or series or class thereof established in accordance...

  13. Bridging the gaps in 18F PET tracer development

    NASA Astrophysics Data System (ADS)

    Campbell, Michael G.; Mercier, Joel; Genicot, Christophe; Gouverneur, Véronique; Hooker, Jacob M.; Ritter, Tobias

    2017-01-01

    As compared to the drug discovery process, the development of new 18F PET tracers lacks a well-established pipeline that advances compounds from academic research to candidacy for (pre)clinical imaging. In order to bridge the gaps between methodological advances and clinical success, we must rethink the development process from training to implementation.

  14. Determination of Stability Constants of Hydrogen and Aluminum Fluorides with a Fluoride-Selective Electrode

    SciTech Connect

    Baumann, E.W.

    2003-01-06

    The ability to directly determine free fluoride ion concentration (or mean activity) simplifies gathering and interpretation of experimental data for studies of metal complexes. In this work, the new lanthanum fluoride electrode was used to measure free fluoride ion in an investigation of the hydrogen-fluoride and aluminum-fluoride systems in NH4NO3.

  15. Synthesis of a phenolic precursor and its efficient O-[18F]fluoroethylation with purified no-carrier-added [18F]2-fluoroethyl brosylate as the labeling agent.

    PubMed

    Jarkas, Nashwa; Voll, Ronald J; Goodman, Mark M

    2013-09-01

    [(18)F]2-Fluoroethyl-p-toluenesulfonate also called [(18)F]2-fluoroethyl tosylate has been widely used for labeling radioligands for positron emission tomography (PET). [(18)F]2-Fluoroethyl-4-bromobenzenesulfonate, also called [(18)F]2-fluoroethyl brosylate ([(18)F]F(CH2)2OBs), was used as an alternative radiolabeling agent to prepare [(18)F]FEOHOMADAM, a fluoroethoxy derivative of HOMADAM, by O-fluoroethylating the phenolic precursor. Purified by reverse-phase HPLC, the no-carrier-added [(18)F]F(CH2)2OBs was obtained in an average radiochemical yield (RCY) of 35%. The reaction of the purified and dried [(18)F]F(CH2)2OBs with the phenolic precursor was performed by heating in DMF and successfully produced [(18)F]FEOHOMADAM, after HPLC purification, in RCY of 21%.

  16. Conversion Reaction Mechanisms in Lithium Ion Batteries: Study of the Binary Metal Fluoride Electrodes

    SciTech Connect

    Wang, Feng; Robert, Rosa; Chernova, Natasha A.; Pereira, Nathalie; Omenya, Fredrick; Badway, Fadwa; Hua, Xiao; Ruotolo, Michael; Zhang, Ruigang; Wu, Lijun; Volkov, Vyacheslav; Su, Dong; Key, Baris; Whittingham, M. Stanley; Grey, Clare P.; Amatucci, Glenn G.; Zhu, Yimei; Graetz, Jason

    2015-10-15

    Materials that undergo a conversion reaction with lithium (e.g., metal fluorides MF{sub 2}: M = Fe, Cu, ...) often accommodate more than one Li atom per transition-metal cation, and are promising candidates for high-capacity cathodes for lithium ion batteries. However, little is known about the mechanisms involved in the conversion process, the origins of the large polarization during electrochemical cycling, and why some materials are reversible (e.g., FeF{sub 2}) while others are not (e.g., CuF{sub 2}). In this study, we investigated the conversion reaction of binary metal fluorides, FeF{sub 2} and CuF{sub 2}, using a series of local and bulk probes to better understand the mechanisms underlying their contrasting electrochemical behavior. X-ray pair-distribution-function and magnetization measurements were used to determine changes in short-range ordering, particle size and microstructure, while high-resolution transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS) were used to measure the atomic-level structure of individual particles and map the phase distribution in the initial and fully lithiated electrodes. Both FeF{sub 2} and CuF{sub 2} react with lithium via a direct conversion process with no intercalation step, but there are differences in the conversion process and final phase distribution. During the reaction of Li{sup +} with FeF{sub 2}, small metallic iron nanoparticles (<5 nm in diameter) nucleate in close proximity to the converted LiF phase, as a result of the low diffusivity of iron. The iron nanoparticles are interconnected and form a bicontinuous network, which provides a pathway for local electron transport through the insulating LiF phase. In addition, the massive interface formed between nanoscale solid phases provides a pathway for ionic transport during the conversion process. These results offer the first experimental evidence explaining the origins of the high lithium reversibility in FeF{sub 2}. In contrast

  17. Optimization of precursor synthesis, formulation and stability of 1′-[18 F] fluoroethyl-β-d-lactose ([18 F]FEL) for preclinical studies in detection of pancreatic cancer

    PubMed Central

    Paolillo, Vincenzo; De Palatis, Louis; Alauddin, Mian M.

    2014-01-01

    Introduction 1′-[18 F]Fluoroethyl-β-d-lactose ([18 F]FEL) is a new PET imaging agent for early detection of pancreatic cancer and hepatocellular carcinoma. We previously reported the syntheses of [18 F]FEL using a bromo- and a tosyl- precursor, followed by an improved method using a nosyl-precursor. However, some steps in the synthesis of the precursor appeared to be problematic producing low yields. Here, we report on an optimized method for synthesis of the precursor and production of [18 F]FEL; we also describe [18 F]FEL’s formulation and stability. Methods Acetylation of d-lactose 1 was performed following a literature procedure to obtain 1′,2′,3′,6′,2,3,4,6-d-lactose octa-acetate 2a/2b. Bromination of 2a/2b was performed using HBr/acetic acid to produce 1'-bromo-2′,3′,6′,2,3,4,6-hepta-O-acetyl-α-d-lactose 3. Coupling of 3 with ethylene glycol was performed in the presence of Ag-tosylate and an excess of ethylene glycol to produce 4a. Compound 4a was reacted with p-nitrophenylsulfonyl chloride to produce the nosyl derivative 5. Radiofluorination of 5 was performed using K[18 F]fluoride/kryptofix to obtain 6, which was purified by HPLC and hydrolyzed with Na-methoxide to produce 7. Results Compound 2 (2a/2b) was obtained in 83% yield as a mixture of two anomeric products. Compound 3 was obtained from the 2a/2b mixture in 80% yield as one product. Coupling of 3 with ethylene glycol produced 4a in 90% yield. Compound 5 was obtained in 64% yield, and radiofluorination of 5 produced 6 in 62.5% ± 7.5% yields (n = 8). Hydrolysis of 6 with Na-methoxide produced 7 in 42.0% ± 7.0% yield (n = 8) from the end of bombardment. Conclusions A simple 4-step synthesis of the precursor, compound 5, has been achieved with improved yields. A new formulation of [18 F]FEL has been developed that allows the product to remain stable at ambient temperature for use in animal studies. This improved synthesis of the precursor and stable formulation of [18 F]FEL should

  18. One-Step Synthesis of Titanium Oxyhydroxy-Fluoride Rods and Research on the Electrochemical Performance for Lithium-ion Batteries and Sodium-ion Batteries

    NASA Astrophysics Data System (ADS)

    Li, Biao; Gao, Zhan; Wang, Dake; Hao, Qiaoyan; Wang, Yan; Wang, Yongkun; Tang, Kaibin

    2015-10-01

    Titanium oxyhydroxy-fluoride, TiO0.9(OH)0.9F1.2 · 0.59H2O rods with a hexagonal tungsten bronze (HTB) structure, was synthesized via a facile one-step solvothermal method. The structure, morphology, and component of the products were characterized by X-ray powder diffraction (XRD), thermogravimetry (TG), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), inductively coupled plasma optical emission spectroscopy (ICP-OES), ion chromatograph, energy-dispersive X-ray (EDX) analyses, and so on. Different rod morphologies which ranged from nanoscale to submicron scale were simply obtained by adjusting reaction conditions. With one-dimension channels for Li/Na intercalation/de-intercalation, the electrochemical performance of titanium oxyhydroxy-fluoride for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) was also studied. Electrochemical tests revealed that, for LIBs, titanium oxyhydroxy-fluoride exhibited a stabilized reversible capacity of 200 mAh g-1 at 25 mA g-1 up to 120 cycles in the electrode potential range of 3.0-1.2 V and 140 mAh g-1 at 250 mA g-1 up to 500 cycles, especially; for SIBs, a high capacity of 100 mAh g-1 was maintained at 25 mA g-1 after 115 cycles in the potential range of 2.9-0.5 V.

  19. Application of Palladium-Mediated 18F-Fluorination to PET Radiotracer Development: Overcoming Hurdles to Translation

    PubMed Central

    Kamlet, Adam S.; Neumann, Constanze N.; Lee, Eunsung; Carlin, Stephen M.; Moseley, Christian K.; Stephenson, Nickeisha; Hooker, Jacob M.; Ritter, Tobias

    2013-01-01

    New chemistry methods for the synthesis of radiolabeled small molecules have the potential to impact clinical positron emission tomography (PET) imaging, if they can be successfully translated. However, progression of modern reactions from the stage of synthetic chemistry development to the preparation of radiotracer doses ready for use in human PET imaging is challenging and rare. Here we describe the process of and the successful translation of a modern palladium-mediated fluorination reaction to non-human primate (NHP) baboon PET imaging–an important milestone on the path to human PET imaging. The method, which transforms [18F]fluoride into an electrophilic fluorination reagent, provides access to aryl–18F bonds that would be challenging to synthesize via conventional radiochemistry methods. PMID:23554994

  20. Application of palladium-mediated (18)F-fluorination to PET radiotracer development: overcoming hurdles to translation.

    PubMed

    Kamlet, Adam S; Neumann, Constanze N; Lee, Eunsung; Carlin, Stephen M; Moseley, Christian K; Stephenson, Nickeisha; Hooker, Jacob M; Ritter, Tobias

    2013-01-01

    New chemistry methods for the synthesis of radiolabeled small molecules have the potential to impact clinical positron emission tomography (PET) imaging, if they can be successfully translated. However, progression of modern reactions from the stage of synthetic chemistry development to the preparation of radiotracer doses ready for use in human PET imaging is challenging and rare. Here we describe the process of and the successful translation of a modern palladium-mediated fluorination reaction to non-human primate (NHP) baboon PET imaging-an important milestone on the path to human PET imaging. The method, which transforms [(18)F]fluoride into an electrophilic fluorination reagent, provides access to aryl-(18)F bonds that would be challenging to synthesize via conventional radiochemistry methods.

  1. 18F-fluorodeoxyglucose and 18F-flumazenil positron emission tomography in patients with refractory epilepsy

    PubMed Central

    Topakian, Raffi; Pichler, Robert

    2016-01-01

    Abstract Background Epilepsy is a neurological disorder characterized by epileptic seizures as a result of excessive neuronal activity in the brain. Approximately 65 million people worldwide suffer from epilepsy; 20–40% of them are refractory to medication therapy. Early detection of disease is crucial in the management of patients with epilepsy. Correct localization of the ictal onset zone is associated with a better surgical outcome. The modern non-invasive techniques used for structural-functional localization of the seizure focus includes electroencephalography (EEG) monitoring, magnetic resonance imaging (MRI), single photon emission tomography/computed tomography (SPECT/CT) and positron emission tomography/computed tomography (PET/CT). PET/CT can predict surgical outcome in patients with refractory epilepsy. The aim of the article is to review the current role of routinely used tracer 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG) as well as non routinely used 18F-Flumazenil (18F-FMZ) tracers PET/CT in patients with refractory epilepsy. Conclusions Functional information delivered by PET and the morphologic information delivered by CT or MRI are essential in presurgical evaluation of epilepsy. Nowadays 18F-FDG PET/CT is a routinely performed imaging modality in localization of the ictal onset zone in patients with refractory epilepsy who are unresponsive to medication therapy. Unfortunately, 18F-FDG is not an ideal PET tracer regarding the management of patients with epilepsy: areas of glucose hypometabolism do not correlate precisely with the proven degree of change within hippocampal sclerosis, as observed by histopathology or MRI. Benzodiazepine-receptor imaging is a promising alternative in nuclear medicine imaging of epileptogenic focus. The use of 11C-FMZ in clinical practice has been limited by its short half-life and necessitating an on-site cyclotron for production. Therefore, 18F-FMZ might be established as one of the tracers of choice for patients

  2. Adaptation of a commercial ion selective fluoride electrode to a tubular configuration for analysis by flow methodologies.

    PubMed

    Conceição, António C L; dos Santos, M M Correia; Gonçalves, M L S Simões

    2008-06-30

    The determination of fluoride ions in water samples is accomplished by using a tubular flow through detector constructed by drilling a channel through a commercially available LaF(3) crystal electrode in such a way that the original contacts of the non-modified unit are maintained. Its performance when incorporated in both FIA and SIA systems was evaluated and the results show that the tubular unit retains the characteristics of the non-modified electrode. In SIA conditions an extended linear range of response and lower detection limit were achieved when compared with the electrode performance in FIA conditions. These aspects together with the additional advantage of low sample and reagent consumptions in SIA when compared to FIA, makes the incorporation of the proposed tubular ISE in a SIA system the preferred approach for on line determination and monitoring of fluoride content in natural water samples.

  3. Dimethylsulphoxide solvate of N,N‧-dinaphthylthiourea and its selective interactions with fluoride and copper(II) ions

    NASA Astrophysics Data System (ADS)

    Tarai, Arup; Baruah, Jubaraj B.

    2015-07-01

    A dimethylsulphoxide solvate of N,N‧-dinaphthylthiourea was structurally characterised and shown to have syn-anti conformation. Deprotonation of N,N‧-dinaphthylthiourea by tetrabutylammonium fluoride causes specific colour change, which was studied by UV-visible, fluorescence and 1H-NMR spectroscopy. It was also observed that among various metal chlorides, copper(II) chloride specifically causes colour change on interactions with N,N‧-dinaphthylthiourea which provided a means for detection of copper(II) ions, on the other hand other metal(II) chlorides were silent towards such changes. Control experiments established formation of copper thiourea complex in 1:2 metal to ligand ratio. It was also found that addition of tetrabutylammonium fluoride caused increase in fluorescence emission which was not caused by other tetrabutylammonium salts; similarly among various metal chlorides, copper(II) chloride specifically quenched fluorescence emission of N,N‧-dinaphthylthiourea.

  4. Ex-vivo biodistribution and micro-PET/CT imaging of 18F-FDG, 18F-FLT, 18F-FMISO, and 18F-AlF-NOTA-PRGD2 in a prostate tumor-bearing nude mouse model.

    PubMed

    Cheng, Zhuzhong; Wei, Renbo; Wu, Changqiang; Qing, Haomiao; Jiang, Xiao; Lu, Hao; Chen, Shirong; Li, Xinping; Xu, Guohui; Ai, Hua

    2015-09-01

    (18)F-Fluorodeoxyglucose ((18)F-FDG), (18)F-fluoro-3'-deoxy-3'-L-fluorothymidine ((18)F-FLT), (18)F-fluoromisonidazole ((18)F-FMISO), and (18)F-AlF-NOTA-PRGD2 ((18)F-RGD) are all commonly used PET tracers for tumor diagnosis based on different mechanisms of tissue uptake. This study compared the ex-vivo biodistribution and PET/computed tomography (CT) imaging studies of these four PET tracers in a xenograft prostate tumor-bearing mouse model. Nude mice were inoculated with 5 × 10 PC-3 cells in the right armpit. The ex-vivo biodistribution of (18)F-FDG, (18)F-FLT, (18)F-FMISO, and (18)F-RGD at 30, 60, 90, and 120 min after injection was compared. Micro-PET/CT images of (18)F-FDG, (18)F-FLT, and (18)F-RGD were acquired at 60 min, whereas (18)F-FMISO images were acquired at 90 min after injection. The tumors were clearly visualized by micro-PET/CT using all four PET tracers. Ex-vivo biodistribution results showed highest tumor accumulation and tumor-to-muscle ratio of (18)F-FDG at each time point, accompanied by physiologically high uptakes in the brain, heart, and intestinal tract. Modest uptake of (18)F-FLT and (18)F-FMISO in tumors was observed at 60 and 90 min after injection, with less interference from other tissues compared with (18)F-FDG. Besides, (18)F-RGD also exhibited high tumor specificity; however, relatively low uptake was observed in the tumor. Our results demonstrated the potential of (18)F-FMISO and (18)F-FLT in the diagnosis of xenograft prostate cancer.

  5. Fluorometric selective detection of fluoride ions in aqueous media using Ag doped CdS/ZnS core/shell nanoparticles.

    PubMed

    Boxi, Siddhartha Sankar; Paria, Santanu

    2016-01-14

    The presence of fluoride ions in drinking water plays an important role in human health. For that reason, maintaining the optimum concentration of fluoride ions in drinking water is essential, as both low and excess (above the permissible level) concentrations can cause different health problems, such as fluorosis, urolithiasis, kidney failure, cancer, and can even lead to death. So, development of a simple and low cost method for the detection of fluoride ions in water is highly desirable. In this study, a fluorometric method based on Ag-CdS/Ag-ZnS core/shell nanoparticles is developed for fluoride ion detection. The method was tested in aqueous solution at different pH values. The selectivity and sensitivity of the fluorescence probe was checked in the presence of other anions (Cl(-), Br(-), I(-), NO3(-) SO4(2-), HCO3(-), HPO4(2-), CH3COO(-), and H2PO4(-)) and found there is no significant interference of these associated ions. The fluoride ion concentration was varied in the range 190-22 800 μg L(-1) and a lower detection limit was obtained as 99.7 μg L(-1).

  6. Subchronic toxic effects of fluoride ion on the survival and behaviour of the aquatic snail Potamopyrgus antipodarum (Hydrobiidae, Mollusca).

    PubMed

    Alonso, Álvaro; Camargo, Julio A

    2011-04-01

    Short-term bioassays usually assess lethal effects of pollutants in animals, whereas subchronic bioassays are more suited for assessing effects on animal behaviour. Among them, videotaped bioassays are an improvement in the behavioural monitoring because they are easily and cheaply implemented. The present study focuses on the assessment of subchronic (14-day) effects of fluoride ion on the survival, proportion of dead plus immobile animals, and velocity (monitored by a videotaping and image analysis system) of the aquatic snail Potamopyrgus antipodarum (Hydrobiidae, Mollusca). One control and three nominal fluoride concentrations (5, 20, and 40 mg F(-)/l [actual mean concentrations of 5.2, 17.5, and 37.0 mg F(-)/l, respectively]) were used. Each treatment (including the control) was replicated 12 times. Mortality, number of dead plus immobile animals, and velocity were monitored after 0, 7, and 14 days of exposure. After 14 days, animals exposed to 40 mg F(-)/l showed higher mortality, number of dead, and immobile individuals than control animals. Snails exposed to 5 and 20 mg F(-)/l were not affected by fluoride ion regarding these endpoints. In contrast, snails exposed to 20 mg F(-)/l for 7 and 14 days showed lower velocity than control animals. Therefore, velocity was sensitive to environmental fluoride concentrations and as such is a useful parameter for ecologic risk assessment. In addition, videotaping allowed us to detect behavioural patrons in velocity at very short exposures (seconds) during the monitoring process by showing that the velocity of snails must be monitored at least during the course of several minutes. We conclude that in P. antipodarum, velocity is a more sensitive endpoint than the classic mortality and immobility endpoints.

  7. Chemical modification of the poly(vinylidene fluoride-trifluoroethylene) copolymer surface through fluorocarbon ion beam deposition

    SciTech Connect

    Hsu, W.-D.; Jang, Inkook; Sinnott, Susan B.

    2007-07-15

    Classical molecular dynamics simulations are used to study the effects of continuous fluorocarbon ion beam deposition on a poly(vinylidene fluoride-trifluoroethylene) [P(VDF-trFE)] surface, a polymer with electromechanical properties. Fluorocarbon plasma processing is widely used to chemically modify surfaces and deposit thin films. It is well accepted that polyatomic ions and neutrals within low-energy plasmas have a significant effect on the surface chemistry induced by the plasma. The deposition of mass selected fluorocarbon ions is useful to isolate the effects specific to polyatomic ions. Here, the differences in the chemical interactions of C{sub 3}F{sub 5}{sup +} and CF{sub 3}{sup +} ions with the P(VDF-trFE) surface are examined. The incident energy of the ions in both beams is 50 eV. The CF{sub 3}{sup +} ions are predicted to be more effective at fluorinating the P(VDF-trFE) surface than C{sub 3}F{sub 5}{sup +} ions. At the same time, the C{sub 3}F{sub 5}{sup +} ions are predicted to be more effective at growing fluorocarbon thin films. The simulations also reveal how the deposition process might ultimately modify the electromechanical properties of this polymer surface.

  8. Reproducibility of Static and Dynamic 18F-FDG, 18F-FLT, and 18F-FMISO MicroPET Studies in a Murine Model of HER2+ Breast Cancer

    PubMed Central

    Whisenant, Jennifer G.; Peterson, Todd E.; Fluckiger, Jacob U.; Tantawy, Mohammed Noor; Ayers, Gregory D.; Yankeelov, Thomas E.

    2013-01-01

    Purpose The objective of this study is to determine the reproducibility of static 2-deoxy-2-[18F] fluoro-D-glucose (18F-FDG), 3′-deoxy-3′-[18F]fluorothymidine (18F-FLT), and [18F]-fluoromisonidazole (18F-FMISO) microPET measurements, as well as kinetic parameters returned from analyses of dynamic 18F-FLT and 18F-FMISO data. Procedures HER2+ xenografts were established in nude mice. Dynamic data were acquired for 60 min, followed by a repeat injection and second scan 6 h later. Reproducibility was assessed for the percent-injected dose per gram (%ID/g) for each radiotracer, and with kinetic parameters (K1–k4, Ki) for 18F-FLT and 18F-FMISO. Results The value needed to reflect a change in tumor physiology is given by the 95 % confidence interval (CI), which is ±14, ±5, and ±6 % for 18F-FDG (n=12), 18F-FLT (n=11), and 18F-FMISO (n=11) %ID/g, respectively. Vd (=K1/k2), k3, and KFLT are the most reproducible 18F-FLT (n=9) kinetic parameters, with 95 % CIs of ±18, ±10, and ±18 %, respectively. Vd and KFMISO are the most reproducible 18F-FMISO kinetic parameters (n=7) with 95 % CIs of ±16 and ±14 %, respectively. Conclusions Percent-injected dose per gram measurements are reproducible and appropriate for detecting treatment-induced changes. Kinetic parameters have larger threshold values, but are potentially sufficiently reproducible to detect treatment response. PMID:22644988

  9. Impact of seawater on distribution of fluoride and other ions in groundwater of Diplo area, Thar Desert Pakistan.

    PubMed

    Rafique, Tahir; Naseem, Shahid; Usmani, Tanzil Haider; Bhanger, Muhammad Iqbal; Shirin, Khaula

    2013-07-01

    The role of seawater dilution, along with other water-quality components, has been studied to determine the causes of spatial distribution of high fluoride concentrations in the groundwater of the Diplo sub-district, Thar Desert, Pakistan. Fluoride ion concentration ranges of up to 7.60 mg/L were discovered, with mean and median values of 1.66 and 1.34 mg/L, respectively. Estimates based on the total dissolved solid (TDS) ratio show the impact of seawater intrusion at a percentage of around 8.05% in the groundwater. The major ion chemistry of water in the central diamond shape of the Piper diagram precisely demarcates the phenomenon of the intrusion of seawater into the study area. The plots of Na+K vs. Ca+Mg (meq/L) and log C1 (mg/L) vs. log Ca+Mg/Na+K (meq/L) indicate a mixing of freshwater with seawater. The molar Na/Na+Cl and Ca/Ca+SO4 ratios of the groundwater, and correlation matrices of major ion chemistry, also show a blending of groundwater with seawater. Mutual relationships among Li+, Sr2+, and C1- ions further substantiate the marked influence of the marine environment on the groundwater in the study area.

  10. Use of fluorides in dental caries management.

    PubMed

    Chu, C H; Mei, May L; Lo, Edward C M

    2010-01-01

    Fluoride is commonly and widely used to prevent and even arrest caries. The clinical effects of fluorides depend on the chemical compounds utilized and the methods used to apply the fluoride ion to the surface of the tooth. Fluorosis has been reported in conjunction with increased doses of fluoride. A coordinated approach to fluoride delivery is essential to avoid the risk of fluorosis.

  11. Determination of Fluoride and Chloride in NU Sample Matrices by Ion Chromatography

    SciTech Connect

    Ray, R.

    2003-05-21

    This study is a demonstration of fluoride and chloride determinations in natural uranium (NU) sample matrices as part of technical task request FSS-ALD-2002-00025 deliverable from Central Laboratory Services.

  12. Determination of Fluoride and Chloride in LEU Sample Matrices by Ion Chromatography

    SciTech Connect

    Ray, R.

    2002-12-06

    This study is a demonstration of fluoride and chloride determinations in Low Enriched Uranium sample matrices as part of technical task request FSS-ALD-2002-00025 deliverable from Central Laboratory Services.

  13. No-carrier-added [.sup.18 F]-N-fluoroalkylspiroperidols

    DOEpatents

    Shiue, Chyng-Yann; Wolf, Alfred P.; Bai, Lan-Qin; Teng, Ren-Tui

    1989-01-01

    There is disclosed radioligands labeled with the position emitting radionuclide [.sup.18 F] suitable for dynamic study in living humans with position emission transaxial tomography. These new [.sup.18 F]-N-fluoroalkylspiroperidols, wherein the alkyl group contains from 2-6 carbon atoms, exhibit extremely high affinity for the dopamine receptors and provide enhanced uptake and retention in the brain concomitant with reduced radiation burden. These characteristics all combine to make these new radioligands useful for mapping dopamine receptors in normal and disease states in the living brain. Additionally, a new synthetic procedure for these radioligands as well as a new procedure for preparing the radiolabeled alkyl halide alkylating reagents are also disclosed.

  14. No-carrier-added (/sup 18/F)-N-methylspiroperidol

    DOEpatents

    Shiue, C.Y.; Fowler, J.S.; Wolf, A.P.

    1985-10-04

    The present invention is directed to the synthesis of a radioligand, labeled with a positron emitting radionuclide which is suitable for dynamic studies in humans using positron emission transaxial tomography. No-carrier-added (NCA) (/sup 18/F)-N-methylspiroperiodl is prepared from four different sustrates: p-nitrobenzonitrile, cyclopropyl p-nitrophenyl ketone, p-cyclopropanoyl-N,N,N-trimethylanilinium iodide and p-cyclopropanoyl-N,N,N-trimethylanilinium perchlorate. The process for the production of NCA (/sup 18/F)-N-methylspiroperidol is a nucleophilic aromatic substitution reaction. Furthermore, the compound of this invention is shown to be effective as a new drug of choice for in vivo examination of dopamine binding sites in a human brain. In particular, this drug is primarily useful in the noninvasive technique of positron emission transaxial tomography (PETT).

  15. Carbon Nanohorns Carried Iron Fluoride Nanocomposite with ultrahigh rate lithium ion storage properties

    PubMed Central

    Fan, Lishuang; Li, Bingjiang; Zhang, Naiqing; Sun, Kening

    2015-01-01

    Novel hierarchical carbon nanohorns (CNHs) carried iron fluoride nanocomposites have been constructed by direct growth of FeF3·0.33H2O nanoparticles on CNHs. In the FeF3·0.33H2O@CNHs nanocomposite, the mesopore CNHs play the role as conductive matrix and robust carrier to support the FeF3·0.33H2O nanoparticles. The intimate conductive contact between the two components can build up an express way of electron transfer for rapid Li+ insertion/extraction. The CNHs can not only suppress the growth and agglomeration of FeF3·0.33H2O during the crystallization process, but also sever as an “elastic confinement” to support FeF3·0.33H2O. As was to be expected, the hierarchical FeF3·0.33H2O@CNHs nanocomposite exhibits impressive rate capability and excellent cycle performance. Markedly, the nanocomposite proves stable, ultrahigh rate lithium ion storage properties of 81 mAh g−1 at charge/discharge rate of 50 C (a discharge/charge process only takes 72 s). The integration of high electron conductivity, confined nano sized FeF3·0.33H2O (~5 nm), hierarchical mesopores CNHs and the “elastic confinement” support, the FeF3·0.33H2O@CNHs nanocomposite demonstrates excellent ultrahigh rate capability and good cycling properties. PMID:26173994

  16. Comparison of [18F]-FMISO, [18F]-FAZA and [18F]-HX4 for PET imaging of hypoxia--a simulation study.

    PubMed

    Wack, Linda J; Mönnich, David; van Elmpt, Wouter; Zegers, Catharina M L; Troost, Esther G C; Zips, Daniel; Thorwarth, Daniela

    2015-01-01

    To investigate the effect of hypoxia tracer properties on positron emission tomography (PET) image quality for three tracers [18F]-fluoromisonidazole (FMISO), [18F]-fluoroazomycinarabinoside (FAZA) and [18F]-flortanidazole (HX4), using mathematical simulations based on microscopic tumor tissue sections. Oxygen distribution and tracer binding was mathematically simulated on immunohistochemically stained cross-sections of tumor xenografts. Tracer diffusion properties were determined based on available literature. Blood activity and clearance over a four-hour period post-injection (p.i.) were derived from clinical dynamic PET scans of patients suffering from head and neck or bronchial cancer. Simulations were performed both for average patient blood activities and for individual patients, and image contrast between normoxic and hypoxic tissue areas was determined over this four-hour period p.i. On average, HX4 showed a six-fold higher clearance than FMISO and an almost three-fold higher clearance than FAZA based on the clinical PET data. The absolute variation in clearance was significantly higher for HX4 than for FMISO (standard deviations of 5.75 *10-5 s-1 vs. 1.55 *10-5 s-1). The absolute tracer activity in these scans at four hours p.i. was highest for FMISO and lowest for HX4. Simulated contrast at four hours p.i. was highest for HX4 (2.39), while FMISO and FAZA were comparable (1.67 and 1.75, respectively). Variations in contrast of 7-11% were observed for each tracer depending on the vascularization patterns of the chosen tissue. Higher variations in clearance for HX4 resulted in an increased inter-patient variance in simulated contrast at four hours p.i. In line with recent experimental and clinical data, the results suggest that HX4 is a promising new tracer that provides high image contrast four hours p.i., though inter-patient variance can be very high. Nevertheless, the widely used tracer FMISO provides a robust and reproducible signal four hours p.i., but

  17. A Comparative Study of Noninvasive Hypoxia Imaging with 18F-Fluoroerythronitroimidazole and 18F-Fluoromisonidazole PET/CT in Patients with Lung Cancer.

    PubMed

    Wei, Yuchun; Zhao, Wei; Huang, Yong; Yu, Qingxi; Zhu, Shouhui; Wang, Suzhen; Zhao, Shuqiang; Hu, Xudong; Yu, Jinming; Yuan, Shuanghu

    2016-01-01

    This is a clinical study to compare noninvasive hypoxia imaging using 18F-fluoroerythronitroimidazole (18F-FETNIM) and 18F-fluoromisonidazole (18F-FMISO) positron emission tomography/computed tomography (PET/CT) in patients with inoperable stages III-IV lung cancer. A total of forty-two patients with inoperable stages III-IV lung cancer underwent 18F-FETNIM PET/CT (n = 18) and 18F-FMISO PET/CT (n = 24) before chemo/radiation therapy. The standard uptake values (SUVs) of malignant and normal tissues depict 18F-FETNIM PET/CT and 18F-FMISO PET/CT uptake. Tumor-to-blood ratios (T/B) were used to quantify hypoxia. All patients with lung cancer underwent 18F-FETNIM PET/CT and 18F-FMISO PET/CT successfully. Compared to 18F-FMISO, 18F-FETNIM showed similar uptake in muscle, thyroid, spleen, pancreas, heart, lung and different uptake in blood, liver, and kidney. Significantly higher SUV and T/B ratio with 18F-FMISO (2.56±0.77, 1.98±0.54), as compared to 18F-FETNIM (2.12±0.56, 1.42±0.33) were seen in tumor, P = 0.022, <0.001. For the patients with different histopathological subtypes, no significant difference of SUV (or T/B ratio) was observed both in 18F-FMISO and 18F-FETNIM in tumor. A significantly different SUV (or T/B ratio) was detected between < = 2cm, 2~5cm, and >5cm groups in 18F-FMISO PET/CT, P = 0.015 (or P = 0.029), whereas no difference was detected in 18F-FMISO PET/CT, P = 0.446 (or P = 0.707). Both 18F-FETNIM and 18F-FMISO showed significantly higher SUVs (or T/B ratios) in stage IV than stage III, P = 0.021, 0.013 (or P = 0.032, 0.02). 18F-FMISO showed significantly higher uptake than 18F-FETNIM in tumor/non-tumor ratio and might be a better hypoxia tracer in lung cancer.

  18. A Comparative Study of Noninvasive Hypoxia Imaging with 18F-Fluoroerythronitroimidazole and 18F-Fluoromisonidazole PET/CT in Patients with Lung Cancer

    PubMed Central

    Huang, Yong; Yu, Qingxi; Zhu, Shouhui; Wang, Suzhen; Zhao, Shuqiang; Hu, Xudong; Yu, Jinming; Yuan, Shuanghu

    2016-01-01

    Purpose This is a clinical study to compare noninvasive hypoxia imaging using 18F-fluoroerythronitroimidazole (18F-FETNIM) and 18F-fluoromisonidazole (18F-FMISO) positron emission tomography/computed tomography (PET/CT) in patients with inoperable stages III–IV lung cancer. Methods A total of forty-two patients with inoperable stages III–IV lung cancer underwent 18F-FETNIM PET/CT (n = 18) and 18F-FMISO PET/CT (n = 24) before chemo/radiation therapy. The standard uptake values (SUVs) of malignant and normal tissues depict 18F-FETNIM PET/CT and 18F-FMISO PET/CT uptake. Tumor-to-blood ratios (T/B) were used to quantify hypoxia. Results All patients with lung cancer underwent 18F-FETNIM PET/CT and 18F-FMISO PET/CT successfully. Compared to 18F-FMISO, 18F-FETNIM showed similar uptake in muscle, thyroid, spleen, pancreas, heart, lung and different uptake in blood, liver, and kidney. Significantly higher SUV and T/B ratio with 18F-FMISO (2.56±0.77, 1.98±0.54), as compared to 18F-FETNIM (2.12±0.56, 1.42±0.33) were seen in tumor, P = 0.022, <0.001. For the patients with different histopathological subtypes, no significant difference of SUV (or T/B ratio) was observed both in 18F-FMISO and 18F-FETNIM in tumor. A significantly different SUV (or T/B ratio) was detected between < = 2cm, 2~5cm, and >5cm groups in 18F-FMISO PET/CT, P = 0.015 (or P = 0.029), whereas no difference was detected in 18F-FMISO PET/CT, P = 0.446 (or P = 0.707). Both 18F-FETNIM and 18F-FMISO showed significantly higher SUVs (or T/B ratios) in stage IV than stage III, P = 0.021, 0.013 (or P = 0.032, 0.02). Conclusion 18F-FMISO showed significantly higher uptake than 18F-FETNIM in tumor/non-tumor ratio and might be a better hypoxia tracer in lung cancer. PMID:27322586

  19. 5 d-4 f luminescence of Nd3+, Gd3+, Er3+, Tm3+, and Ho3+ ions in crystals of alkaline earth fluorides

    NASA Astrophysics Data System (ADS)

    Radzhabov, E. A.; Prosekina, E. A.

    2011-09-01

    The vacuum ultraviolet emission spectra of alkaline-earth fluoride (CaF2, SrF2, BaF2) crystals with rare earth impurity ions (Nd, Gd, Er, Tm, Ho) have been investigated. The main luminescence bands are described well by the transitions from the lowest excited 5 d state to different 4 f levels of rare earth ions.

  20. CHARACTERIZATION OF TANK 18F WALL AND SCALE SAMPLES

    SciTech Connect

    Hay, Michael; Click, Damon; Diprete, c.; Diprete, David

    2010-03-01

    Samples from the wall of Tank 18F were obtained to determine the associated source term using a special wall sampling device. Two wall samples and a scale sample were obtained and characterized at the Savannah River National Laboratory (SRNL). All the analyses of the Tank 18F wall and scale samples met the targeted detection limits. The upper wall samples show {approx}2X to 6X higher concentrations for U, Pu, and Np on an activity per surface area basis than the lower wall samples. On an activity per mass basis, the upper and lower wall samples show similar compositions for U and Pu. The Np activity is still {approx}2.5X higher in the upper wall sample on a per mass basis. The scale sample contains 2-3X higher concentrations of U, Pu, and Sr-90 than the wall samples on an activity per mass basis. The plutonium isotopics differ for all three wall samples (upper, lower, and scale samples). The Pu-238 appears to increase as a proportion of total plutonium as you move up the tank wall from the lowest sample (scale sample) to the upper wall sample. The elemental composition of the scale sample appears similar to other F-Area PUREX sludge compositions. The composition of the scale sample is markedly different than the material on the floor of Tank 18F. However, the scale sample shows elevated Mg and Ca concentrations relative to typical PUREX sludge as do the floor samples.

  1. Effect of gemcitabine on the uptake of (18)F-fluorodeoxyglucose and (18)F-fluorothymidine in lung adenocarcinoma A549 cells and the animal tumor model.

    PubMed

    Zhang, Bin; Deng, Sheng-Ming; Guo, Ling-Chuan; Dong, Jia-Jia; Zhu, Yan-Bo; Gao, Yuan; Wang, Zhen-Xin; Cho, William C

    2016-01-01

    Gemcitabine is the first-line drug for nonsmall cell lung cancer, and 18F-fluorodeoxyglucose. (18F-FDG) and 18F-fluorothymidine. (18F-FLT) are positron emission tomography. (PET) imaging agents. The aim of this study was to explore the effect of gemcitabine on the uptake of 18F-FDG and 18F-FLT in A549 cells and the animal tumor model. The inhibitory effects of gemcitabine on cell growth were determined by tetrazolium blue method, and uptake rates of 18F-FDG and 18F-FLT were determined under the same conditions. The adenocarcinoma-bearing nude mice before and after gemcitabine treatments were performed microPET imaging with 18F-FDG and 18F-FLT. Hematoxylin and eosin staining and immunohistochemical analysis of tumor specimens were conducted. After the administration of gemcitabine, positive correlations were observed between inhibition of 18F-FDG or 18F.FLT uptake and cell growth. (r = 0.957 or 0.981, P < 0.01). SUVmax values by 18F-FDG in the tumor, before and after administration of gemcitabine at the dose of 60 mmol/L, revealed an increase by. (35.83 ± 10.58) %. After administration of 120 mmol/L gemcitabine, the SUVmax values decreased by (12.37 ± 7.33) %. The SUVmax values by 18F-FLT at the dose of 60 mmol/L gemcitabine revealed a decrease by (56.47 ± 10.83) %. Pathological staining showed obvious vasodilation and invasion of lymphocytes and plasma cells at the dose of 60 mmol/L, and the expression of glucose transporter protein-1, Ki-67 and proliferating cell nuclear antigen in tumor cells were inhibited. 18F-FLT imaging can assess the proliferation of tumor cells and 18F-FDG imaging can reflect the changes of the tumor microenvironment after administration of gemcitabine.

  2. Pharmacokinetic evaluation of the tau PET radiotracer 18F-T807 (18F-AV-1451) in human subjects

    PubMed Central

    Wooten, Dustin W.; Guehl, Nicolas J.; Verwer, Eline E.; Shoup, Timothy M.; Yokell, Daniel L.; Zubcevik, Nevena; Vasdev, Neil; Zafonte, Ross D.; Johnson, Keith A.; Fakhri, Georges El; Normandin, Marc D.

    2017-01-01

    18F-T807 is a PET radiotracer developed for imaging tau protein aggregates, which are implicated in neurological disorders including Alzheimer's disease (AD) and traumatic brain injury (TBI). The current study characterizes 18F-T807 pharmacokinetics in human subjects using dynamic PET imaging and metabolite-corrected arterial input functions. Methods Nine subjects (4 control, 3 with history of TBI, 2 mild cognitive impairment (MCI) due to suspected AD) underwent dynamic PET imaging for up to 120 minutes after bolus injection of 18F-T807 with arterial blood sampling. Total volume of distribution (VT) was estimated using compartmental modeling (one- and two-tissue configurations) and graphical analysis techniques (Logan and MA1 regression methods). Reference region-based methods of quantification were explored including Logan distribution volume ratio (DVR) and static standardized uptake value ratio (SUVR) utilizing the cerebellum as a reference tissue. Results Percent unmetabolized 18F-T807 in plasma followed a single exponential with T1/2 of 17.0±4.2 minutes. Metabolite corrected plasma radioactivity concentration fit a bi-exponential (T1/2: 18.1±5.8; 2.4±0.5 minutes). 18F-T807 in gray matter peaked quickly (SUV >2 at ∼5 minutes). Compartmental modeling resulted in good fits and the two-tissue model with estimated blood volume correction (2Tv) performed best, particularly in regions with elevated binding. VT was greater in MCI subjects than controls in the occipital, parietal, and temporal cortices as well as the posterior cingulate gyrus, precuneus, and mesial temporal cortex. High focal uptake was found in the posterior corpus callosum of a TBI subject. Plots from Logan and MA1 graphical methods became linear by 30 minutes, yielding regional estimates of VT in excellent agreement with compartmental analysis and providing high quality parametric maps when applied in voxelwise fashion. Reference region based approaches including Logan DVR (t*=55 min) and SUVR

  3. Kinetic Modeling and Graphical Analysis of 18F-Fluoromethylcholine (FCho), 18F-Fluoroethyltyrosine (FET) and 18F-Fluorodeoxyglucose (FDG) PET for the Fiscrimination between High-Grade Glioma and Radiation Necrosis in Rats

    PubMed Central

    Lybaert, Kelly; Moerman, Lieselotte; Descamps, Benedicte; Deblaere, Karel; Boterberg, Tom; Kalala, Jean-Pierre; Van den Broecke, Caroline; De Vos, Filip; Vanhove, Christian; Goethals, Ingeborg

    2016-01-01

    Background Discrimination between glioblastoma (GB) and radiation necrosis (RN) post-irradiation remains challenging but has a large impact on further treatment and prognosis. In this study, the uptake mechanisms of 18F-fluorodeoxyglucose (18F-FDG), 18F-fluoroethyltyrosine (18F-FET) and 18F-fluoromethylcholine (18F-FCho) positron emission tomography (PET) tracers were investigated in a F98 GB and RN rat model applying kinetic modeling (KM) and graphical analysis (GA) to clarify our previous results. Methods Dynamic 18F-FDG (GB n = 6 and RN n = 5), 18F-FET (GB n = 5 and RN n = 5) and 18F-FCho PET (GB n = 5 and RN n = 5) were acquired with continuous arterial blood sampling. Arterial input function (AIF) corrections, KM and GA were performed. Results The influx rate (Ki) of 18F-FDG uptake described by a 2-compartmental model (CM) or using Patlak GA, showed more trapping (k3) in GB (0.07 min-1) compared to RN (0.04 min-1) (p = 0.017). K1 of 18F-FET was significantly higher in GB (0.06 ml/ccm/min) compared to RN (0.02 ml/ccm/min), quantified using a 1-CM and Logan GA (p = 0.036). 18F-FCho was rapidly oxidized complicating data interpretation. Using a 1-CM and Logan GA no clear differences were found to discriminate GB from RN. Conclusions Based on our results we concluded that using KM and GA both 18F-FDG and 18F-FET were able to discriminate GB from RN. Using a 2-CM model more trapping of 18F-FDG was found in GB compared to RN. Secondly, the influx of 18F-FET was higher in GB compared to RN using a 1-CM model. Important correlations were found between SUV and kinetic or graphical measures for 18F-FDG and 18F-FET. 18F-FCho PET did not allow discrimination between GB and RN. PMID:27559736

  4. PET neuroimaging studies of [18F]CABS13 in a double transgenic mouse model of Alzheimer’s disease and non-human primates

    PubMed Central

    Liang, Steven H.; Holland, Jason P.; Stephenson, Nickeisha A.; Kassenbrock, Alina; Rotstein, Benjamin H.; Daignault, Cory P.; Lewis, Rebecca; Collier, Lee; Hooker, Jacob M.; Vasdev, Neil

    2016-01-01

    Fluorine-18 labeled 2-fluoro-8-hydroxyquinoline ([18F]CABS13) is a promising positron emission tomography (PET) radiopharmaceutical based on a metal chelator developed to probe the “metal hypothesis of Alzheimer’s disease”. Herein, a practical radiosynthesis of [18F]CABS13 was achieved by radiofluorination followed by deprotection of an O-benzyloxymethyl group. Automated production and formulation of [18F]CABS13 resulted in 19 ± 5% uncorrected radiochemical yield, relative to starting [18F]fluoride, with ≥95% chemical and radiochemical purities, and high specific activity (>2.5 Ci/μmol) within 80 minutes. Temporal PET neuroimaging studies were carried out in female transgenic B6C3- Tg(APPswe,PSEN1dE9)85Dbo/J (APP/PS1) and age-matched wild-type (WT) B6C3F1/J control mice at 3, 7 and 10 months of age. [18F]CABS13 showed an overall higher uptake and retention of radioactivity in the central nervous system of APP/PS1 mice versus WT mice with increasing age. However, PET/magnetic resonance imaging in normal non-human primates revealed that the tracer had low uptake in the brain and rapid formation of a hydrophilic radiometabolite. Identification of more metabolically stable 18F-hydroxyquinolines that can be readily accessed by the radiochemical strategy presented herein is underway. PMID:25776827

  5. Synthesis and preclinical evaluation of an Al(18)F radiofluorinated GLU-UREA-LYS(AHX)-HBED-CC PSMA ligand.

    PubMed

    Boschi, Stefano; Lee, Jason T; Beykan, Seval; Slavik, Roger; Wei, Liu; Spick, Claudio; Eberlein, Uta; Buck, Andreas K; Lodi, Filippo; Cicoria, Gianfranco; Czernin, Johannes; Lassmann, Michael; Fanti, Stefano; Herrmann, Ken

    2016-11-01

    The aim of this study was to synthesize and preclinically evaluate an (18)F-PSMA positron emission tomography (PET) tracer. Prostate-specific membrane antigen (PSMA) specificity, biodistribution, and dosimetry in healthy and tumor-bearing mice were determined. Several conditions for the labeling of (18)F-PSMA-11 via (18)F-AlF-complexation were screened to study the influence of reaction temperature, peptide amount, ethanol volume, and reaction time. After synthesis optimization, biodistribution and dosimetry studies were performed in C57BL6 mice. For proof of PSMA-specificity, mice were implanted with PSMA-negative (PC3) and PSMA-positive (LNCaP) tumors in contralateral flanks. Static and dynamic microPET/computed tomography (CT) imaging was performed. Quantitative labeling yields could be achieved with >97 % radiochemical purity. The (18)F-PSMA-11 uptake was more than 24-fold higher in PSMA-high LNCaP than in PSMA-low PC3 tumors (18.4 ± 3.3 %ID/g and 0.795 ± 0.260 %ID/g, respectively; p < 4.2e-5). Results were confirmed by ex vivo gamma counter analysis of tissues after the last imaging time point. The highest absorbed dose was reported for the kidneys. The maximum effective dose for an administered activity of 200 MBq was 1.72 mSv. (18)F-PSMA-11 using direct labeling of chelate-attached peptide with aluminum-fluoride detected PSMA-expressing tumors with high tumor-to-liver ratios. The kidneys were the dose-limiting organs. Even by applying the most stringent dosimetric calculations, injected activities of up to 0.56 GBq are feasible.

  6. 18F-FDG super bone marrow uptake

    PubMed Central

    Alam, Mohammed Shah; Fu, Lilan; Ren, Yun-Yan; Wu, Hu-Bing; Wang, Quan-Shi; Han, Yan-Jiang; Zhou, Wen-Lan; Li, Hong-Sheng; Wang, Zhen

    2016-01-01

    Abstract The present study was performed to investigate whether the markedly 2-deoxy-2-(fluorine-18) fluoro-D-glucose (18F-FDG) uptake in the bone marrow (BM) is a presentation of malignant infiltration (MI). Super bone marrow uptake (super BMU) was used to name the markedly 18F-FDG uptake on BM, which was similar to or higher than that of the brain. From April 2008 to December 2015, 31 patients with such presentation were retrospectively reviewed. The 18F-FDG uptake was semiquantified using SUVmax and BM to cerebellum (BM/C) ratio. The origin of super BMU was diagnosed by pathology. Some blood parameters, as well as fever, were also collected and analyzed. For comparison, 106 patients with mildly and moderately uptake in BM and 20 healthy subjects were selected as the control group. Bone marrow MI was diagnosed in 93.5% (29/31) patients with super BMU, which mostly originated from acute leukemia and highly aggressive lymphoma. The super BMU group had markedly higher 18F-FDG uptake in the BM than those of mildly and moderately uptake, and the control subjects (all P = 0.000) and the BM/C ratio reached a high of 1.24 ± 0.36. The incidence of bone marrow MI in the super BMU group was markedly higher than that of mildly and moderately uptake (93.5% vs 36.8%, P = 0.000). Based on the receiver operating characteristic analysis, when cut-off values of BM/C and SUVmax were set at 0.835 and 6.560, the diagnostic specificity for bone marrow MI reached the high levels of 91.4% and 95.7%, respectively. In 15 patients with bone marrow MI, the extra-BM malignant lesions were simultaneously detected by 18F-FDG PET/CT. The liver and the nasal cavity involvements were only found in the patients with lymphoma, but not in those with leukemia. A decrease of leukocyte, hemoglobin, and platelet counts was noted in 48.4%, 86.2%, and 51.5% of patients with bone marrow MI, respectively. The present study revealed that super BMU was a highly potent indicator for the bone

  7. Direct radiolabelling of proteins at cysteine using [18F]-fluorosugars.

    PubMed

    Boutureira, Omar; Bernardes, Gonçalo J L; D'Hooge, François; Davis, Benjamin G

    2011-09-28

    A strategy for the site-specific attachment of 2-deoxy-2-fluorosugars to cysteine and dehydroalanine tagged proteins is reported. When combined with thionation of fluorosugars, such as the widely available (18)F probe 2-deoxy-2-[(18)F]fluoroglucose ([(18)F]FDG), this methodology allows fast and direct access to site-specific [(18)F]FDG-labelled proteins.

  8. Corrosion investigations on zircaloy-4 and titanium dissolver materials for MOX fuel dissolution in concentrated nitric acid containing fluoride ions

    NASA Astrophysics Data System (ADS)

    Jayaraj, J.; Krishnaveni, P.; Krishna, D. Nanda Gopala; Mallika, C.; Mudali, U. Kamachi

    2016-05-01

    Aqueous reprocessing of plutonium-rich mixed oxide fuels require fluoride as a dissolution catalyst in boiling nitric acid for an effective dissolution of the spent fuel. High corrosion rates were obtained for the candidate dissolver materials zircaloy-4 (Zr-4) and commercial pure titanium (CP-Ti grade 2) in boiling 11.5 M HNO3 + 0.05 M NaF. Complexing the fluoride ions either with Al(NO3)3 or ZrO(NO3)2 aided in decreasing the corrosion rates of Zr-4 and CP-Ti. From the obtained corrosion rates it is concluded that CP-Ti is a better dissolver material than Zr-4 for extended service life in boiling 11.5 M HNO3 + 0.05 M NaF, when complexed with 0.15 M ZrO(NO3)2. XPS analysis confirmed the presence of TiO2 and absence of fluoride on the surface of CP-Ti samples, indicating that effective complexation had occurred in solution leading to passivation of the metal and imparting high corrosion resistance.

  9. Anthraimidazoledione Based Reversible and Reusable Selective Chemosensors for Fluoride Ion: Naked-Eye, Colorimetric and Fluorescence "ON-OFF".

    PubMed

    Bhattacharyya, Bhaswati; Kundu, Arijit; Guchhait, Nikhil; Dhara, Kaliprasanna

    2017-02-09

    Novel anthraimidazoledione-based compounds (1-3) are synthesized as selective colorimetric and fluorescent sensors for fluoride ion. The binding properties of the probes (1-3) are studied with different anions in acetonitrile solvent. Spectral red shifts in the absorption spectra and 'turn-off' emission are observed when fluoride is added to 1-3. The striking green to orange color change in the ambient light is thought to be due to the deprotonation of the N-H proton of the imidazole moiety of the probes by the basic F(-) ion. Interestingly, in all three cases the nonfluorescent probe-F(-) solutions, on treatment with copper perchlorate, show distinct color change from orange to golden yellow with resumption of fluorescence intensity. Furthermore, the reversibility of sensors (1-3) for the detection of F(-) ion is tested for four cycles indicating that "ON-OFF-ON" mechanism is operative. Test strip based on sensor 2 acts as a reusable cost-effective F(-) sensor.

  10. Origins of Large Voltage Hysteresis in High-Energy-Density Metal Fluoride Lithium-Ion Battery Conversion Electrodes.

    PubMed

    Li, Linsen; Jacobs, Ryan; Gao, Peng; Gan, Liyang; Wang, Feng; Morgan, Dane; Jin, Song

    2016-03-02

    Metal fluorides and oxides can store multiple lithium ions through conversion chemistry to enable high-energy-density lithium-ion batteries. However, their practical applications have been hindered by an unusually large voltage hysteresis between charge and discharge voltage profiles and the consequent low-energy efficiency (<80%). The physical origins of such hysteresis are rarely studied and poorly understood. Here we employ in situ X-ray absorption spectroscopy, transmission electron microscopy, density functional theory calculations, and galvanostatic intermittent titration technique to first correlate the voltage profile of iron fluoride (FeF3), a representative conversion electrode material, with evolution and spatial distribution of intermediate phases in the electrode. The results reveal that, contrary to conventional belief, the phase evolution in the electrode is symmetrical during discharge and charge. However, the spatial evolution of the electrochemically active phases, which is controlled by reaction kinetics, is different. We further propose that the voltage hysteresis in the FeF3 electrode is kinetic in nature. It is the result of ohmic voltage drop, reaction overpotential, and different spatial distributions of electrochemically active phases (i.e., compositional inhomogeneity). Therefore, the large hysteresis can be expected to be mitigated by rational design and optimization of material microstructure and electrode architecture to improve the energy efficiency of lithium-ion batteries based on conversion chemistry.

  11. Hydrogeochemical processes controlling changes in fluoride ion concentration within alluvial and hard rock aquifers in a part of a semi-arid region of Northern India

    NASA Astrophysics Data System (ADS)

    Singh, Priyadarshini; Ashthana, Harshita; Rena, Vikas; Kumar, Pardeep; Mukherjee, Saumitra

    2017-04-01

    Geochemical signatures from alluvial and hard rock aquifers in a part of Northern India elucidate the chemical processes controlling fluctuations in fluoride ion concentration linked to changes in major ion groundwater chemistry. Majority of samples from the hard rock and the alluvial aquifers for pre-monsoon show both carbonate and silicate weathering, ion exchange, evaporation and rock water interaction as the processes controlling major ion chemistry whereas for post monsoon samples, contribution of silicate weathering and ion exchange process were observed. Evaporative processes causing the increase in Na+ ion concentration in premonsoon enhance the reverse ion exchange processes causing increase in Ca2+ ions which impedes fluorite mineral dissolution in the premonsoon groundwater samples within the study area. Alternately, it is observed that the removal of Ca2+ ion from solution plays a key role in increase in fluorite mineral dissolution despite its saturation in groundwater in the postmonsoon samples. Also, ion exchange process on clay surfaces is more pronounced in the postmonsoon samples leading to the uptake of Ca2+ ion upon release of Na+ and K+ ion in solution. Ca2+ ion concentration is inversely correlated with F- ion concentration in both the aquifers in the postmonsoon season validating the role of calcite precipitation as a major reason for the fluoride ion increase. Moreover, increase in silicate weathering in the postmonsoon samples leads to increase in clay particles acting as suitable sites for ion exchange enhancing Ca2+ removal from groundwater. Cationic dominance of Na+ ion in the post monsoon samples also validates the occurrence of this process. Collectively, these processes set the ideal conditions for increase in the fluoride ion concentration particularly in the alluvium aquifer waters in the postmonsoon season Keywords: geochemistry, ion-exchange, rock-water interaction, mineral dissolution, weathering.

  12. Fully automated synthesis of [(18) F]fluoro-dihydrotestosterone ([(18) F]FDHT) using the FlexLab module.

    PubMed

    Ackermann, Uwe; Lewis, Jason S; Young, Kenneth; Morris, Michael J; Weickhardt, Andrew; Davis, Ian D; Scott, Andrew M

    2016-08-01

    Imaging of androgen receptor expression in prostate cancer using F-18 FDHT is becoming increasingly popular. With the radiolabelling precursor now commercially available, developing a fully automated synthesis of [(18) F] FDHT is important. We have fully automated the synthesis of F-18 FDHT using the iPhase FlexLab module using only commercially available components. Total synthesis time was 90 min, radiochemical yields were 25-33% (n = 11). Radiochemical purity of the final formulation was > 99% and specific activity was > 18.5 GBq/µmol for all batches. This method can be up-scaled as desired, thus making it possible to study multiple patients in a day. Furthermore, our procedure uses 4 mg of precursor only and is therefore cost-effective. The synthesis has now been validated at Austin Health and is currently used for [(18) F]FDHT studies in patients. We believe that this method can easily adapted by other modules to further widen the availability of [(18) F]FDHT.

  13. Comparative evaluation of (18)F-FLT and (18)F-FDG for detecting cardiac and extra-cardiac thoracic involvement in patients with newly diagnosed sarcoidosis.

    PubMed

    Norikane, Takashi; Yamamoto, Yuka; Maeda, Yukito; Noma, Takahisa; Dobashi, Hiroaki; Nishiyama, Yoshihiro

    2017-08-29

    (18)F-FDG PET has been used in sarcoidosis for diagnosis and determination of the extent of the disease. However, assessing inflammatory lesions in cardiac sarcoidosis using (18)F-FDG can be challenging because it accumulates physiologically in normal myocardium. Another radiotracer, 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT), has been investigated as a promising PET tracer for evaluating tumor proliferative activity. In contrast to (18)F-FDG, (18)F-FLT uptake in the normal myocardium is low. The purpose of this retrospective study was to compare the uptake of (18)F-FLT and (18)F-FDG in the evaluation of cardiac and extra-cardiac thoracic involvement in patients with newly diagnosed sarcoidosis. Data for 20 patients with newly diagnosed sarcoidosis were examined. (18)F-FLT and (18)F-FDG PET/CT studies had been performed at 1 h after each radiotracer injection. The patients had fasted for at least 18 h before (18)F-FDG PET/CT but were given no special dietary instructions regarding the period before (18)F-FLT PET/CT. Uptake of (18)F-FLT and (18)F-FDG was examined visually and semiquantitatively using maximal standardized uptake value (SUVmax). Two patients had cardiac sarcoidosis, 7 had extra-cardiac thoracic sarcoidosis, and 11 had both cardiac and extra-cardiac thoracic sarcoidosis. On visual analysis for diagnosis of cardiac sarcoidosis, 4/20 (18)F-FDG scans were rated as inconclusive because the (18)F-FDG pattern was diffuse, whereas no FLT scans were rated as inconclusive. The sensitivity of (18)F-FDG PET/CT for detection of cardiac sarcoidosis was 85%; specificity, 100%; and accuracy, 90%. The corresponding values for (18)F-FLT PET/CT were 92, 100, and 95%, respectively. Using semiquantitative analysis of cardiac sarcoidosis, the mean (18)F-FDG SUVmax was significantly higher than the mean (18)F-FLT SUVmax (P < 0.005). Both (18)F-FDG and (18)F-FLT PET/CT studies detected all 24 extra-cardiac lesions. Using semiquantitative analysis of extra

  14. Improved and optimized one-pot method for N-succinimidyl-4-[(18)F]fluorobenzoate ([(18)F]SFB) synthesis using microwaves.

    PubMed

    Li, Kang-Po; Hu, Ming-Kuan; Kwang-Fu Shen, Clifton; Lin, Wei-Yu; Hou, Shuang; Zhao, Li-Bo; Cheng, Cheng-Yi; Shen, Daniel H

    2014-12-01

    N-Succinimidyl-4-[(18)F]fluorobenzoate ([(18)F]SFB) is a potential prosthetic agent for novel tracer development in positron emission tomography (PET). Previously, we reported a microwave-assisted one-pot synthesis of [(18)F]SFB with high efficacy. Herein, we reveal an improved and optimized approach based on this former model for producing [(18)F]SFB. With optimized approaches, the entire protocol can be completed within 25min, and [(18)F]SFB is generated in satisfactory quality for direct use without further purification via high-performance liquid chromatography.

  15. Synthesis of [(18)F]FMISO in a flow-through microfluidic reactor: Development and clinical application.

    PubMed

    Zheng, Ming-Qiang; Collier, Lee; Bois, Frederic; Kelada, Olivia J; Hammond, Kelvin; Ropchan, Jim; Akula, Murthy R; Carlson, David J; Kabalka, George W; Huang, Yiyun

    2015-06-01

    The PET radiotracer [(18)F]FMISO has been used in the clinic to image hypoxia in tumors. The aim of the present study was to optimize the radiochemical parameters for the preparation of [(18)F]FMISO using a microfluidic reaction system. The main parameters evaluated were (1) precursor concentration, (2) reaction temperature, and (3) flow rate through the microfluidic reactor. Optimized conditions were then applied to the batch production of [(18)F]FMISO for clinical research use. For the determination of optimal reaction conditions within a flow-through microreactor synthesizer, 5-400 μL the precursor and dried [(18)F]fluoride solutions in acetonitrile were simultaneously pushed through the temperature-controlled reactor (60-180 °C) with defined flow rates (20-120 μL/min). Radiochemical incorporation yields to form the intermediate species were determined using radio-TLC. Hydrolysis to remove the protecting group was performed following standard vial chemistry to afford [(18)F]FMISO. Optimum reaction parameters for the microfluidic set-up were determined as follows: 4 mg/mL of precursor, 170 °C, and 100 μL/min pump rate per reactant (200 μL/min reaction overall flow rate) to prepare the radiolabeled intermediate. The optimum hydrolysis condition was determined to be 2N HCl for 5 min at 100 °C. Large-scale batch production using the optimized conditions gave the final, ready for human injection [(18)F]FMISO product in 28.4 ± 3.0% radiochemical yield, specific activity of 119 ± 26 GBq/μmol, and >99% radiochemical and chemical purity at the end of synthesis (n = 4). By using the NanoTek microfluidic synthesis system, [(18)F]FMISO was successfully prepared with good specific activity and high radiochemical purity for human use. The product generated from large-scale batch production using flow chemistry is currently being used in clinical research. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Visualization of Fluoride Ions In Vivo Using a Gadolinium(III)-Coumarin Complex-Based Fluorescence/MRI Dual-Modal Probe

    PubMed Central

    Wang, Yue; Song, Renfeng; Feng, Huan; Guo, Ke; Meng, Qingtao; Chi, Haijun; Zhang, Run; Zhang, Zhiqiang

    2016-01-01

    A new Gadolinium(III)–coumarin complex, DO3A-Gd-CA, was designed and prepared as a dual-modal probe for simultaneous fluorescence and relaxivity responses to fluoride ions (F−) in aqueous media and mice. DO3A-Gd-CA was designed by using Gd(III) center as an MRI signal output unit and fluoride binding site, and the 4-(diethylamino)-coumarin-3-carboxylic acid (CA) as a fluorescence reporter. Upon the addition of fluoride ions to the solution of DO3A-Gd-CA, the liberation of the coordinated CA ligand led to a 5.7-fold fluorescence enhancement and a 75% increase in the longitudinal relaxivity (r1). The fluorescent detection limit for fluoride ions was determined to be 8 μM based on a 3σ/slope. The desirable features of the proposed DO3A-Gd-CA, such as high sensitivity and specificity, reliability at physiological pH and low cytotoxicity enable its application in visualization of fluoride ion in mice. The successful in vivo imaging indicates that DO3A-Gd-CA could be potentially used in biomedical diagnosis fields. PMID:27999298

  17. Direct observation of Nd{sup 3+} and Tm{sup 3+} ion distributions in oxy-fluoride glass ceramics containing PbF{sub 2} nanocrystals

    SciTech Connect

    Zhang, Jihong; Zhao, Zhiyong; Liu, Chao; Zhang, Gaoke; Zhao, Xiujian; Heo, Jong; Jiang, Yang

    2014-12-15

    Nd{sup 3+} and Tm{sup 3+}, doped oxy-fluoride glasses and glass ceramics were prepared by conventional melt-quenching and subsequent heat-treatment, respectively. β-PbF{sub 2} nanocrystals with diameter 50 –100 nm formed in the glass matrix after heat treatment. The Stark splitting in absorption peaks, enhanced photoluminescence and prolonged lifetimes that β-PbF{sub 2} nanocrystal formation increased the luminescence of rare earth ions. Both Nd{sup 3+} and Tm{sup 3+} ions were incorporated into nanocrystals that were enriched in lead and fluorine, and deficient in oxygen. - Highlights: • EELS analysis for rare-earth ion distribution in oxy-fluoride glass ceramics • No significant changes in lifetimes of Nd{sup 3+}, while obvious change for Tm{sup 3+} • Direct evidence of Nd{sup 3+} and Tm{sup 3+} aggregation into fluoride nanocrystals.

  18. An evaluation of 2-deoxy-2-[18F]fluoro-D-glucose and 3'-deoxy-3'-[18F]-fluorothymidine uptake in human tumor xenograft models.

    PubMed

    Keen, Heather; Pichler, Bernd; Kukuk, Damaris; Duchamp, Olivier; Raguin, Olivier; Shannon, Aoife; Whalley, Nichola; Jacobs, Vivien; Bales, Juliana; Gingles, Neill; Ricketts, Sally-Ann; Wedge, Stephen R

    2012-06-01

    The aim of this study is to assess the variability of 2-deoxy-2-[(18)F]fluoro-D: -glucose ([(18)F]-FDG) and 3'-deoxy-3'-[(18)F]-fluorothymidine ([(18)F]-FLT) uptake in pre-clinical tumor models and examine the relationship between imaging data and related histological biomarkers. [(18)F]-FDG and [(18)F]-FLT studies were carried out in nine human tumor xenograft models in mice. A selection of the models underwent histological analysis for endpoints relevant to radiotracer uptake. Comparisons were made between in vitro uptake, in vivo imaging, and ex vivo histopathology data using quantitative and semi-quantitative analysis. In vitro data revealed that [1-(14)C]-2-deoxy-D: -glucose ([(14)C]-2DG) uptake in the tumor cell lines was variable. In vivo, [(18)F]-FDG and [(18)F]-FLT uptake was highly variable across tumor types and uptake of one tracer was not predictive for the other. [(14)C]-2DG uptake in vitro did not predict for [(18)F]-FDG uptake in vivo. [(18)F]-FDG SUV was inversely proportional to Ki67 and necrosis levels and positively correlated with HKI. [(18)F]-FLT uptake positively correlated with Ki67 and TK1. When evaluating imaging biomarkers in response to therapy, the choice of tumor model should take into account in vivo baseline radiotracer uptake, which can vary significantly between models.

  19. A pilot study of the value of 18F-Fluoro-deoxy-thymidine (18F-FLT) PET/CT in predicting viable lymphoma in residual 18F-FDG avid masses following completion of therapy

    PubMed Central

    Mena, Esther; Lindenberg, M Liza; Turkbey, Baris I; Shih, Joanna; Logan, Jean; Adler, Stephen; Wong, Karen; Wilson, Wyndham; Choyke, Peter L; Kurdziel, KA

    2016-01-01

    Despite its success in diagnosing and staging lymphoma, 18F-FDG PET/CT can be falsely positive in areas of post-treatment inflammation. 3′-18F-Fluoro-3′-deoxy-l-thymidine (18F-FLT) is a structural analog of the DNA constituent thymidine; its uptake correlates with cellular proliferation. This pilot study evaluates the ability of 18F-FLT PET/CT to distinguish viable lymphoma from post treatment inflammatory changes in 18F-FDG-avid residual masses. Methods 21 lymphoma patients with at least one 18F-FDG avid residual mass after therapy, underwent 18F-FLT PET/CT imaging. 18F-FDG and 18F-FLT uptake values were compared, including quantitative pharmacokinetic parameters extracted from the 18F-FLT time activity curves (TACs) generated from dynamic data using graphical and non-linear compartmental modeling. Results The true nature of the residual mass was confirmed by biopsy in 12 patients: 8 positive and 4 negative for viable lymphoma and by followup CT and/or repeat 18F-FDG PET/CT imaging over 1 year: among 9 patients 7 lesions resolved or decreased and 2 showed growth indicative of lymphoma. 18F-FLT PET SUVest.max was significantly higher in tumors than in benign lesions (5.5±2.2 vs. 1.7±0.6; p<0.0001), while the difference in 18F-FDG SUVs was not significant (malignant 7.8±3.8 vs. benign 5.4±2.4; p=0.11). All of the benign lesions had an 18F-FLT SUVest.max less than 3.0. Conclusion 18F-FLT shows improved specificity over 18F-FDG in distinguishing residual lymphoma from post treatment inflammation and may be useful in the evaluation of patients with residual 18F-FDG-positive masses after completing therapy. PMID:25144214

  20. Stereotactic Comparison Study of 18F-Alfatide and 18F-FDG PET Imaging in an LLC Tumor-Bearing C57BL/6 Mouse Model

    PubMed Central

    Wei, Yu-Chun; Gao, Yongsheng; Zhang, Jianbo; Fu, Zheng; Zheng, Jinsong; Liu, Ning; Hu, Xudong; Hou, Wenhong; Yu, Jinming; Yuan, Shuanghu

    2016-01-01

    This study aimed to stereotactically compare the PET imaging performance of 18F-Alfatide (18F-ALF-NOTA-PRGD2, denoted as 18F-Alfatide) and 18F-fluorodeoxyglucose (FDG) and immunohistochemistry (IHC) staining in Lewis lung carcinoma (LLC) tumor-bearing C57BL/6 mouse model. 18F-FDG standard uptake values (SUVs) were higher than 18F-Alfatide SUVs in tumors, most of the normal tissues and organs except for the bladder. Tumor-to-brain, tumor-to-lung, and tumor-to-heart ratios of 18F-Alfatide PET were significantly higher than those of 18F-FDG PET (P < 0.001). The spatial heterogeneity of the tumors was detected, and the tracer accumulation enhanced from the outer layer to the inner layer consistently using the two tracers. The parameters of the tumors were significantly correlated with each other between 18F-FDG SUV and GLUT-1 (R = 0.895, P < 0.001), 18F-Alfatide SUV and αvβ3 (R = 0.595, P = 0.019), 18F-FDG SUV and 18F-Alfatide SUV (R = 0.917, P < 0.001), and GLUT-1 and αvβ3 (R = 0.637, P = 0.011). Therefore, 18F-Alfatide PET may be an effective tracer for tumor detection, spatial heterogeneity imaging and an alternative supplement to 18F-FDG PET, particularly for patients with enhanced characteristics in the brain, chest tumors or diabetes, meriting further study. PMID:27350554

  1. Synthesis and basic evaluation of 7α-(3-[(18)F]fluoropropyl)-testosterone and 7α-(3-[(18)F]fluoropropyl)-dihydrotestosterone.

    PubMed

    Okamoto, Mayumi; Naka, Kyosuke; Ishiwata, Kiichi; Shimizu, Isao; Toyohara, Jun

    2017-01-01

    7α-Substituted androgen derivatives may have the potential to visualize androgen receptors with positron emission tomography. In the present study, we synthesized fluoropropyl derivatives of 7α-(3-[(18)F]fluoropropyl)-testosterone ([(18)F]7) and 7α-(3-[(18)F]fluoropropyl)-dihydrotestosterone ([(18)F]15), and characterized their in vitro binding, in vivo biodistribution, and performed blocking studies in mature androgen deprived male rats. We synthesized [(18)F]7 and [(18)F]15. In vitro binding to recombinant rat AR ligand binding domain protein was determined using a competitive radiometric ligand-binding assay with the high-affinity synthetic androgen [17α-methyl-(3)H]-methyltrienolone ([(3)H]R1881). In vivo biodistribution was performed in mature male rats treated with diethylstilbestrol (chemical castration). A blocking study was performed by co-administration of dihydrotestosterone (36 µg/animal). 7α-(3-Fluoropropyl)-testosterone (7) and 7α-(3-fluoropropyl)-dihydrotestosterone (15) showed competitive binding to recombinant rat AR ligand binding domain protein. The IC50 value of 15 (13.0 ± 3.3 nM) was higher than 7 (47.8 ± 10.0 nM). In contrast to the AR binding affinity, the ventral prostate uptake of [(18)F]7 and [(18)F]15 at 2 h post-injection was similar (0.07 % injected dose/g of tissue). A blocking study indicated that specific binding of [(18)F]15 is observed in the ventral prostate. [(18)F]7 and [(18)F]15 showed moderate levels of bone uptake, which indicates moderate metabolic de-fluorination in rodents. [(18)F]15 is better than [(18)F]7 in terms of radiochemical yield, in vitro binding affinity, prostate specific binding and stability against in vivo metabolic de-fluorination. However, the net uptake level of [(18)F]15 in prostate might be insufficient for in vivo visualization. Although [(18)F]7 and [(18)F]15 improved in vivo stability against de-fluorination, other basic characterization data in rodents were not superior to the

  2. One-Step Synthesis of Titanium Oxyhydroxy-Fluoride Rods and Research on the Electrochemical Performance for Lithium-ion Batteries and Sodium-ion Batteries.

    PubMed

    Li, Biao; Gao, Zhan; Wang, Dake; Hao, Qiaoyan; Wang, Yan; Wang, Yongkun; Tang, Kaibin

    2015-12-01

    Titanium oxyhydroxy-fluoride, TiO0.9(OH)0.9F1.2 · 0.59H2O rods with a hexagonal tungsten bronze (HTB) structure, was synthesized via a facile one-step solvothermal method. The structure, morphology, and component of the products were characterized by X-ray powder diffraction (XRD), thermogravimetry (TG), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), inductively coupled plasma optical emission spectroscopy (ICP-OES), ion chromatograph, energy-dispersive X-ray (EDX) analyses, and so on. Different rod morphologies which ranged from nanoscale to submicron scale were simply obtained by adjusting reaction conditions. With one-dimension channels for Li/Na intercalation/de-intercalation, the electrochemical performance of titanium oxyhydroxy-fluoride for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) was also studied. Electrochemical tests revealed that, for LIBs, titanium oxyhydroxy-fluoride exhibited a stabilized reversible capacity of 200 mAh g(-1) at 25 mA g(-1) up to 120 cycles in the electrode potential range of 3.0-1.2 V and 140 mAh g(-1) at 250 mA g(-1) up to 500 cycles, especially; for SIBs, a high capacity of 100 mAh g(-1) was maintained at 25 mA g(-1) after 115 cycles in the potential range of 2.9-0.5 V.

  3. Fluoride ions as modifiers of the oxide layer produced by plasma electrolytic oxidation on AZ91D magnesium alloy

    NASA Astrophysics Data System (ADS)

    Kazanski, Barbara; Kossenko, Alexey; Zinigrad, Michael; Lugovskoy, Alex

    2013-12-01

    Plasma electrolytic oxidation (PEO) is a powerful technique allowing hardening and corrosion protection of valve metals due to formation of an oxide layer on the metal surface. PEO produces much thicker oxide layers as compared to anodizing, which is of critical importance for many technological applications. The present research investigated the influence of the fluoride ion concentration on the composition, structure and morphology of PEO layers on the magnesium alloy AZ91D. The obtained oxide layers were characterized with XRD, SEM, EDS and tested for corrosion resistance by linear sweep voltammetry in 3.5% NaCl medium. During this investigation it was found that KF addition produces significant changes in the structure and properties of the oxide layers. Fluorine was detected as an amorphous phase in the vicinity of the base metal for both alloys and plausible mechanism was suggested to explain these phenomena. Fluoride ions have pronounced catalytic activity and their presence considerably increases the thickness of the oxide layer. Depending on the process parameters, significant improvement of the corrosion stability of AZ91D alloy is achieved by the use of PEO.

  4. In Vivo Imaging with an αvβ6 Specific Peptide Radiolabeled using 18F-“Click” Chemistry: Evaluation and Comparison with the Corresponding 4-[18F]Fluorobenzoyl- and 2-[18F]Fluoropropionyl-Peptides

    PubMed Central

    Hausner, Sven H.; Marik, Jan; Gagnon, M. Karen J.; Sutcliffe, Julie L.

    2009-01-01

    Numerous radiolabeled peptides have been utilized for in vivo imaging of a variety of cell-surface receptors. For applications in PET using [18F]fluorine, peptides are radiolabeled via a prosthetic group approach. We previously developed solution-phase 18F-“click” radiolabeling and solid-phase radiolabeling using 4-[18F]fluorobenzoic and 2-[18F]fluoropropionic acids. Here we compare the 3 different radiolabeling approaches and report the effects on PET imaging and pharmacokinetics. The prosthetic groups did have an influence; metabolites with significantly different polarities were observed. PMID:18785727

  5. Long-term quality assurance of [(18)F]-fluorodeoxyglucose (FDG) manufacturing.

    PubMed

    Gaspar, Ludovit; Reich, Michal; Kassai, Zoltan; Macasek, Fedor; Rodrigo, Luis; Kruzliak, Peter; Kovac, Peter

    2016-01-01

    Nine years of experience with 2286 commercial synthesis allowed us to deliver comprehensive information on the quality of (18)F-FDG production. Semi-automated FDG production line using Cyclone 18/9 machine (IBA Belgium), TRACERLab MXFDG synthesiser (GE Health, USA) using alkalic hydrolysis, grade "A" isolator with dispensing robotic unit (Tema Sinergie, Italy), and automatic control system under GAMP5 (minus2, Slovakia) was assessed by TQM tools as highly reliable aseptic production line, fully compliant with Good Manufacturing Practice and just-in-time delivery of FDG radiopharmaceutical. Fluoride-18 is received in steady yield and of very high radioactive purity. Synthesis yields exhibited high variance connected probably with quality of disposable cassettes and chemicals sets. Most performance non-conformities within the manufacturing cycle occur at mechanical nodes of dispensing unit. The long-term monitoring of 2286 commercial synthesis indicated high reliability of automatic synthesizers. Shewhart chart and ANOVA analysis showed that minor non-compliances occurred were mostly caused by the declinations of less experienced staff from standard operation procedures, and also by quality of automatic cassettes. Only 15 syntheses were found unfinished and in 4 cases the product was out-of-specification of European Pharmacopoeia. Most vulnerable step of manufacturing was dispensing and filling in grade "A" isolator. Its cleanliness and sterility was fully controlled under the investigated period by applying hydrogen peroxide vapours (VHP). Our experience with quality assurance in the production of [(18)F]-fluorodeoxyglucose (FDG) at production facility of BIONT based on TRACERlab MXFDG production module can be used for bench-marking of the emerging manufacturing and automated manufacturing systems.

  6. Long-term quality assurance of [18F]-fluorodeoxyglucose (FDG) manufacturing

    PubMed Central

    Gaspar, Ludovit; Reich, Michal; Kassai, Zoltan; Macasek, Fedor; Rodrigo, Luis; Kruzliak, Peter; Kovac, Peter

    2016-01-01

    Nine years of experience with 2286 commercial synthesis allowed us to deliver comprehensive information on the quality of 18F-FDG production. Semi-automated FDG production line using Cyclone 18/9 machine (IBA Belgium), TRACERLab MXFDG synthesiser (GE Health, USA) using alkalic hydrolysis, grade “A” isolator with dispensing robotic unit (Tema Sinergie, Italy), and automatic control system under GAMP5 (minus2, Slovakia) was assessed by TQM tools as highly reliable aseptic production line, fully compliant with Good Manufacturing Practice and just-in-time delivery of FDG radiopharmaceutical. Fluoride-18 is received in steady yield and of very high radioactive purity. Synthesis yields exhibited high variance connected probably with quality of disposable cassettes and chemicals sets. Most performance non-conformities within the manufacturing cycle occur at mechanical nodes of dispensing unit. The long-term monitoring of 2286 commercial synthesis indicated high reliability of automatic synthesizers. Shewhart chart and ANOVA analysis showed that minor non-compliances occurred were mostly caused by the declinations of less experienced staff from standard operation procedures, and also by quality of automatic cassettes. Only 15 syntheses were found unfinished and in 4 cases the product was out-of-specification of European Pharmacopoeia. Most vulnerable step of manufacturing was dispensing and filling in grade “A” isolator. Its cleanliness and sterility was fully controlled under the investigated period by applying hydrogen peroxide vapours (VHP). Our experience with quality assurance in the production of [18F]-fluorodeoxyglucose (FDG) at production facility of BIONT based on TRACERlab MXFDG production module can be used for bench-marking of the emerging manufacturing and automated manufacturing systems. PMID:27508102

  7. In situ TEM studies of micron-sized all-solid-state fluoride ion batteries: Preparation, prospects, and challenges.

    PubMed

    Hammad Fawey, Mohammed; Chakravadhanula, Venkata Sai Kiran; Reddy, Munnangi Anji; Rongeat, Carine; Scherer, Torsten; Hahn, Horst; Fichtner, Maximilian; Kübel, Christian

    2016-07-01

    Trustworthy preparation and contacting of micron-sized batteries is an essential task to enable reliable in situ TEM studies during electrochemical biasing. Some of the challenges and solutions for the preparation of all-solid-state batteries for in situ TEM electrochemical studies are discussed using an optimized focused ion beam (FIB) approach. In particular redeposition, resistivity, porosity of the electrodes/electrolyte and leakage current are addressed. Overcoming these challenges, an all-solid-state fluoride ion battery has been prepared as a model system for in situ TEM electrochemical biasing studies and first results on a Bi/La0.9 Ba0.1 F2.9 half-cell are presented. Microsc. Res. Tech. 79:615-624, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  8. Fluoridation Basics

    MedlinePlus

    ... Water Fluoridation Journal Articles for Community Water Fluoridation Water Fluoridation Basics Recommend on Facebook Tweet Share Compartir ... because of tooth decay. History of Fluoride in Water In the 1930s, scientists examined the relationship between ...

  9. [18F FDG PET-Applications in Oncology].

    PubMed

    Răileanu, Irena; Rusu, V; Stefănescu, Cipriana; Cinotti, L; Hountis, D

    2002-01-01

    In the first part our intention was, essentially, to present the particularities of glucose tumoral cells metabolism, PET components, the synthesis of 18F FDG and the detection of unknown cancers. This second part makes reference about mainly types of tumors who benefit by FDG-PET indications. Clinical PET has a rapid growth because of its use in cancer diagnosis and management. According with published studies all over the world, the sensibility and specificity of FDG-PET, noninvasive method, is higher than that of the conventional methods like CT, IRM, ultrasonography. PET is en excellent detection method of most of common cancer types and depends not on the histological neoplasm type; the more aggressive is the tumor, more it will uptake the radiotracer. The cost is significant, so the indications must be very precise: evaluating the malignity of solitary pulmonary nodules, evaluating the recurrences of melanoma, colon cancer diagnosis, differentiation between recurrent brain tumor and radiation injury, differential diagnosis of the benign lymph and malign lymph nodes, staging of Hodgkin's and non-Hodgkin's lymphoma, evaluation the response to therapy. Because the PET images are difficult to interpret, appears the necessity of correlation with anatomic images: this was the fusion images beginnings (the PET and CT images combination); now the physiologic information has precise anatomic localization. The growing of this method is very probably, both using 18F FDG -thanks to its highly favorable physical characteristics- and other new radiopharmaceuticals. The clinical cases that illustrate the applications are investigated at CERMEP, Lyon, France.

  10. Mechanisms underlying 18F-fluorodeoxyglucose accumulation in colorectal cancer

    PubMed Central

    Kawada, Kenji; Iwamoto, Masayoshi; Sakai, Yoshiharu

    2016-01-01

    Positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) is a diagnostic tool to evaluate metabolic activity by measuring accumulation of FDG, an analogue of glucose, and has been widely used for detecting small tumors, monitoring treatment response and predicting patients’ prognosis in a variety of cancers. However, the molecular mechanism of FDG accumulation into tumors remains to be investigated. It is well-known that most cancers are metabolically active with elevated glucose metabolism, a phenomenon known as the Warburg effect. The underlying mechanisms for elevated glucose metabolism in cancer tissues are complex. Recent reports have indicated the potential of FDG-PET/CT scans in predicting mutational status (e.g., KRAS gene mutation) of colorectal cancer (CRC), which suggests that FDG-PET/CT scans may play a key role in determining therapeutic strategies by non-invasively predicting treatment response to anti-epidermal growth factor receptor (EGFR) therapy. In this review, we summarize the current findings investigating the molecular mechanism of 18F-FDG accumulation in CRC. PMID:27928469

  11. Comparison of 18F-AIF-NOTA-PRGD2 and 18F-FDG uptake in lymph node metastasis of differentiated thyroid cancer.

    PubMed

    Cheng, Weiwei; Wu, Zhenyu; Liang, Sheng; Fu, Hongliang; Wu, Shuqi; Tang, Yiyun; Ye, Zhiyi; Wang, Hui

    2014-01-01

    A widespread application of integrin αvβ3 imaging has been emerging in both pre-clinical and clinical studies. But few studies reported its value as compared with 18F-FDG PET, especially for differentiated thyroid cancer (DTC). In this study, we compared the tracer uptake of 18F-AIF-NOTA-PRGD2 and 18F-FDG in lymph node metastasis of DTC to evaluate 18F-AIF-NOTA-PRGD2 as compared with 18F-FDG. 20 DTC patients with presumptive lymph node metastasis were examined with 18F-AIF-NOTA-PRGD2 and 18F-FDG PET/CT. 16 patients undergoing fine needle aspiration biopsy (FNAB) were evaluated by cytology results. For lesions without FNAB, the findings of clinical staging procedures served as the standard of reference (including neck ultrasound and serum thyroglobulin). A total of 39 presumptive lymph node metastases were visualized on PET/CT images. 35 lesions were confirmed as malignant by FNAB and other clinical findings. The mean 18F-AIF-NOTA-PRGD2 in radioactive iodine-refractory (RAIR) lesions and benign lesions were 2.5±0.9 and 2.8±0.9 respectively. The mean SUV for 18F-FDG in all malignant lesions was 4.5±1.6 while in benign lesions it was 3.3±1.2. For all malignant lesions, the mean SUV for 18F-FDG was significantly higher than that for 18F-AIF-NOTA-PRGD2 (P<0.05). No significant correlation was found between the SUVs of 18F-AIF-NOTA-PRGD2 and 18F-FDG for 35 lesions (r = 0.114, P = 0.515). Moreover, 15 lesions of which the diameter larger than 1.5 cm had higher 18F-AIF-NOTA-PRGD2 uptake as compared with the lesions smaller than 1.5 cm. Although most lymph node metastases of DTC showed abnormal uptake of 18F-AIF-NOTA-PRGD2, its diagnostic value was inferior to 18F-FDG. No correlation was found between the uptake of 18F-AIF-NOTA-PRGD2 and 18F-FDG, which may suggest the two tracers provide complementary information in DTC lesions.

  12. Comparison of 18F-AIF-NOTA-PRGD2 and 18F-FDG Uptake in Lymph Node Metastasis of Differentiated Thyroid Cancer

    PubMed Central

    Liang, Sheng; Fu, Hongliang; Wu, Shuqi; Tang, Yiyun; Ye, Zhiyi; Wang, Hui

    2014-01-01

    A widespread application of integrin αvβ3 imaging has been emerging in both pre-clinical and clinical studies. But few studies reported its value as compared with 18F-FDG PET, especially for differentiated thyroid cancer (DTC). In this study, we compared the tracer uptake of 18F-AIF-NOTA-PRGD2 and 18F-FDG in lymph node metastasis of DTC to evaluate 18F-AIF-NOTA-PRGD2 as compared with 18F-FDG. Methods 20 DTC patients with presumptive lymph node metastasis were examined with 18F-AIF-NOTA-PRGD2 and 18F-FDG PET/CT. 16 patients undergoing fine needle aspiration biopsy (FNAB) were evaluated by cytology results. For lesions without FNAB, the findings of clinical staging procedures served as the standard of reference (including neck ultrasound and serum thyroglobulin). Results A total of 39 presumptive lymph node metastases were visualized on PET/CT images. 35 lesions were confirmed as malignant by FNAB and other clinical findings. The mean 18F-AIF-NOTA-PRGD2 in radioactive iodine-refractory (RAIR) lesions and benign lesions were 2.5±0.9 and 2.8±0.9 respectively. The mean SUV for 18F-FDG in all malignant lesions was 4.5±1.6 while in benign lesions it was 3.3±1.2. For all malignant lesions, the mean SUV for 18F-FDG was significantly higher than that for 18F-AIF-NOTA-PRGD2 (P<0.05). No significant correlation was found between the SUVs of 18F-AIF-NOTA-PRGD2 and 18F-FDG for 35 lesions (r = 0.114, P = 0.515). Moreover, 15 lesions of which the diameter larger than 1.5cm had higher 18F-AIF-NOTA-PRGD2 uptake as compared with the lesions smaller than 1.5cm. Conclusion Although most lymph node metastases of DTC showed abnormal uptake of 18F-AIF-NOTA-PRGD2, its diagnostic value was inferior to 18F-FDG. No correlation was found between the uptake of 18F-AIF-NOTA-PRGD2 and 18F-FDG, which may suggest the two tracers provide complementary information in DTC lesions. PMID:24956393

  13. Fluoride coatings on orthodontic wire for controlled release of fluorine ion.

    PubMed

    Lee, Su-Hee; Kim, Hae-Won; Kong, Young-Min; Kim, Hyoun-Ee; Lee, Sung-Ho; Chang, Young-Il

    2005-10-01

    The purpose of this study was to develop a new method of releasing fluorine in a controlled manner for applications in the field of orthodontic Ti-based wire, namely the coating of fluorides on Ti. Thin films of two fluoride compounds, CaF(2) and MgF(2), were coated on Ti via the electron-beam evaporation method. The fluorine was released rapidly from the as-deposited MgF(2) coating within a short period(,) and then the release rate slowed down. When the MgF(2) coating was heat treated, this initial burst effect was decreased, but a significant amount of cracks were generated. On the other hand, in the case of the as-deposited CaF(2) coating, fluorine was released linearly for the entire period, without an initial burst. In the heat-treated CaF(2) coatings the trend was similarly observed. The linear fluorine release from the CaF(2) coatings, even in the as-deposited state, was attributed to the high degree of crystallinity of the coatings. A preliminary cell test showed favorable cell viability on both the fluoride coatings. Given their sustained and controlled fluorine release, these fluoride coatings, particularly CaF(2), are suggested to be potentially useful in the field of orthodontic Ti-based wire.

  14. A fluoride-derived electrophilic late-stage fluorination reagent for PET imaging.

    PubMed

    Lee, Eunsung; Kamlet, Adam S; Powers, David C; Neumann, Constanze N; Boursalian, Gregory B; Furuya, Takeru; Choi, Daniel C; Hooker, Jacob M; Ritter, Tobias

    2011-11-04

    The unnatural isotope fluorine-18 ((18)F) is used as a positron emitter in molecular imaging. Currently, many potentially useful (18)F-labeled probe molecules are inaccessible for imaging because no fluorination chemistry is available to make them. The 110-minute half-life of (18)F requires rapid syntheses for which [(18)F]fluoride is the preferred source of fluorine because of its practical access and suitable isotope enrichment. However, conventional [(18)F]fluoride chemistry has been limited to nucleophilic fluorination reactions. We report the development of a palladium-based electrophilic fluorination reagent derived from fluoride and its application to the synthesis of aromatic (18)F-labeled molecules via late-stage fluorination. Late-stage fluorination enables the synthesis of conventionally unavailable positron emission tomography (PET) tracers for anticipated applications in pharmaceutical development as well as preclinical and clinical PET imaging.

  15. [(18)F]Fluoromisonidazole PET in rectal cancer.

    PubMed

    Puri, Tanuj; Greenhalgh, Tessa A; Wilson, James M; Franklin, Jamie; Wang, Lia Mun; Strauss, Victoria; Cunningham, Chris; Partridge, Mike; Maughan, Tim

    2017-09-20

    There is an increasing interest in developing predictive biomarkers of tissue hypoxia using functional imaging for personalised radiotherapy in patients with rectal cancer that are considered for neoadjuvant chemoradiotherapy (CRT). The study explores [(18)F]fluoromisonidazole ([(18)F]FMISO) positron emission tomography (PET) scans for predicting clinical response in rectal cancer patients receiving neoadjuvant CRT. Patients with biopsy-proven rectal adenocarcinoma were imaged at 0-45 min, 2 and 4 h, at baseline and after 8-10 fractions of CRT (week 2). The first 6 patients did not receive an enema (the non-enema group) and the last 4 patients received an enema before PET-CT scan (the enema group). [(18)F]FMISO production failed on 2 occasions. Static PET images at 4 h were analysed using tumour-to-muscle (T:M) SUVmax and tumour-to-blood (T:B) SUVmax. The 0-45 min dynamic PET scans were analysed using Casciari model to report hypoxia and perfusion. Akaike information criteria (AIC) were used to compare data fittings for different pharmacokinetic models. Pathological tumour regression grade was scored using American Joint Committee on Cancer (AJCC) 7.0. Shapiro-Wilk test was used to evaluate the normality of the data. Five out of eleven (5/11) patients were classed as good responders (AJCC 0/1 or good clinical response) and 6/11 as poor responders (AJCC 2/3 or poor clinical response). The median T:M SUVmax was 2.14 (IQR 0.58) at baseline and 1.30 (IQR 0.19) at week 2, and the corresponding median tumour hypoxia volume was 1.08 (IQR 1.31) cm(3) and 0 (IQR 0.15) cm(3), respectively. The median T:B SUVmax was 2.46 (IQR 1.50) at baseline and 1.61 (IQR 0.14) at week 2, and the corresponding median tumour hypoxia volume was 5.68 (IQR 5.86) cm(3) and 0.76 (IQR 0.78) cm(3), respectively. For 0-45 min tumour modelling, the median hypoxia was 0.92 (IQR 0.41) min(-1) at baseline and 0.70 (IQR 0.10) min(-1) at week 2. The median perfusion was 4.10 (IQR 1.71) ml g(-1)

  16. Comparison of 18F-FDG-PET/CT and 18F-FDG-PET/MR imaging in oncology: a systematic review.

    PubMed

    Singnurkar, Amit; Poon, Raymond; Metser, Ur

    2017-06-01

    The aim of this study was to systematically review the literature to evaluate the clinical performance of integrated (18)F-FDG PET/MR as compared with (18)F-FDG PET/CT in oncologic imaging. The literature was searched using MEDLINE and EMBASE via OVID. Studies comparing the diagnostic accuracy of integrated (18)F-FDG PET/MR and (18)F-FDG PET/CT in the diagnosis, staging/restaging, assessment of treatment response, or evaluation of metastasis in patients with suspected or diagnosed cancers were deemed eligible for inclusion. Risk of bias and applicability concerns were assessed using the QUADAS-2 tool. Twenty studies met the inclusion criteria. The overall quality of the studies was rated favorably with bias or applicability concerns in a few studies. Our review suggests that (18)F-FDG PET/MR performs comparably to (18)F-FDG PET/CT in the detection of local lymph node and distant metastases and superiorly in determining the local extent of tumor. SUV obtained from (18)F-FDG PET/MR correlated highly with those obtained from (18)F-FDG PET/CT. Based on early evidence, (18)F-FDG PET/MR is comparable to (18)F-FDG PET/CT in the clinical scenarios examined in this review. The potential for interchangeability of (18)F-FDG PET/MR with (18)F-FDG PET/CT will vary by indication and the body site that is being imaged, with PET scanners integrated with MRI predicted to provide greater detail in the evaluation of local tumor extent, where (18)F-FDG PET/CT can be limited.

  17. Two dimensional fluoride ion conductor RbSn {2}F {5} studied by impedance spectroscopy and {19}F, {119}Sn, and {87}Rb NMR

    NASA Astrophysics Data System (ADS)

    Yamada, K.; Ahmad, M. M.; Ogiso, Y.; Okuda, T.; Chikami, J.; Miehe, G.; Ehrenberg, H.; Fuess, H.

    2004-07-01

    RbSn2F5 is a two-dimensional fluoride ion conductor. It undergoes a first-order phase transition to a superionic state at 368 K. The structure of the low temperature phase has been determined from the Rietveld analysis of the X-ray powder diffraction. The dynamic properties of the fluoride ions in RbSn2F5 have been studied by impedance spectroscopy and solid state NMR. The dc ionic conductivity of this sample shows an abrupt increase at the phase transition temperature. We have obtained the hopping frequency and the concentration of the charge carriers (F- ions) at different temperatures from the analysis of the conductivity spectra using Almond-West formalism. The estimated values of the charge carriers’ concentration agree well with that determined from the structure and were found to be independent of temperature. The relatively small value of the power-law exponent, n ≈ 0.55, supports the two-dimensional property of the investigated material. Furthermore, 19F NMR with simulation has suggested the diffusive motions of the fluoride ions between different sites. In contrast, 119Sn and 87Rb NMR spectra below 250 K supported the intrinsic disordered nature due to the random distribution of the fluoride ion vacancies.

  18. Stabilisation of tetravalent cerium in perchloric acid medium and measurement of the stability constants of its fluoride complexes using ion selective potentiometry.

    PubMed

    Sawant, R M; Rastogi, R K; Mahajan, M A; Chaudhuri, N K

    1996-01-01

    The stability constants of the fluoride complexes of cerium(IV) in 1 M (HClO(4), NaClO(4)) medium have been measured potentiometrically using a fluoride ion-selective electrode. Quantitative oxidation of cerium to its tetravalent state and its stabilisation in the perchlorate medium were accomplished by oxidation with AgO followed by quick addition of a known amount of fluoride ion. This procedure ensures stability of the oxidation state and prevents hydrolysis and polymerisation of Ce(IV). Logarithms of the average values of beta(1), beta(2), beta(3) and beta(4) were estimated to be 7.57+/-0.04, 14.50+/-0.03, 20.13+/-0.37 and 24.14+/-0.10 respectively.

  19. Radiosynthesis and preliminary PET evaluation of (18)F-labeled 2-(1-(3-fluorophenyl)-2-oxo-5-(pyrimidin-2-yl)-1,2-dihydropyridin-3-yl)benzonitrile for imaging AMPA receptors.

    PubMed

    Yuan, Gengyang; Jones, Graham B; Vasdev, Neil; Liang, Steven H

    2016-10-01

    To prompt the development of (18)F-labeled positron emission tomography (PET) tracers for the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor, we have prepared (18)F-labeled 2-(1-(3-fluorophenyl)-2-oxo-5-(pyrimidin-2-yl)-1,2-dihydropyridin-3-yl)benzonitrile ([(18)F]8). The radiosynthesis was achieved by a one-pot two-step method that utilized a spirocyclic hypervalent iodine(III) mediated radiofluorination to prepare the (18)F-labeled 1-bromo-3-fluorobenzene ([(18)F]15) intermediate with K(18)F. A subsequent copper(I) iodide mediated coupling reaction was carried out with 2-(2-oxo-5-(pyrimidin-2-yl)-1,2-dihydropyridin-3-yl)benzonitrile (10) to [(18)F]8 in 10±2% uncorrected radiochemical yield relative to starting (18)F-fluoride with >99% radiochemical purity and 29.6±7.4Gbq/μmol specific activity at the time of injection. PET imaging studies with the title radiotracer in normal mice demonstrated good brain uptake (peak standardized uptake value (SUV)=2.3±0.1) and warrants further in vivo validation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. (18)F-labeled positron emission tomographic radiopharmaceuticals in oncology: an overview of radiochemistry and mechanisms of tumor localization.

    PubMed

    Vallabhajosula, Shankar

    2007-11-01

    Molecular imaging is the visualization, characterization, and measurement of biological processes at the molecular and cellular levels in a living system. At present, positron emission tomography/computed tomography (PET/CT) is one the most rapidly growing areas of medical imaging, with many applications in the clinical management of patients with cancer. Although [(18)F]fluorodeoxyglucose (FDG)-PET/CT imaging provides high specificity and sensitivity in several kinds of cancer and has many applications, it is important to recognize that FDG is not a "specific" radiotracer for imaging malignant disease. Highly "tumor-specific" and "tumor cell signal-specific" PET radiopharmaceuticals are essential to meet the growing demand of radioisotope-based molecular imaging technology. In the last 15 years, many alternative PET tracers have been proposed and evaluated in preclinical and clinical studies to characterize the tumor biology more appropriately. The potential clinical utility of several (18)F-labeled radiotracers (eg, fluoride, FDOPA, FLT, FMISO, FES, and FCH) is being reviewed by several investigators in this issue. An overview of design and development of (18)F-labeled PET radiopharmaceuticals, radiochemistry, and mechanism(s) of tumor cell uptake and localization of radiotracers are presented here. The approval of clinical indications for FDG-PET in the year 2000 by the Food and Drug Administration, based on a review of literature, was a major breakthrough to the rapid incorporation of PET into nuclear medicine practice, particularly in oncology. Approval of a radiopharmaceutical typically involves submission of a "New Drug Application" by a manufacturer or a company clearly documenting 2 major aspects of the drug: (1) manufacturing of PET drug using current good manufacturing practices and (2) the safety and effectiveness of a drug with specific indications. The potential routine clinical utility of (18)F-labeled PET radiopharmaceuticals depends also on

  1. Preparation of 18F-labeled peptides using the copper(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition.

    PubMed

    Gill, Herman S; Marik, Jan

    2011-10-13

    An optimized procedure for preparing fluorine-18 ((18)F)-labeled peptides by the copper-catalyzed azide-alkyne 1,3-dipolar cyloaddition (CuAAC) is presented here. The two-step radiosynthesis begins with the microwave-assisted nucleophilic (18)F-fluorination of a precursor containing a terminal p-toluenesulfonyl, terminal azide and polyethylene glycol backbone. The resulting (18)F-fluorinated azide-containing building block is coupled to an alkyne-decorated peptide by the CuAAC. The reaction is accelerated by the copper(I)-stabilizing ligand bathophenanthroline disulfonate and can be performed in either reducing or nonreducing conditions (e.g., to preserve disulfide bonds). After an HPLC purification, (18)F-labeled peptide can be obtained with a 31 ± 6% radiochemical yield (n = 4, decay-corrected from (18)F-fluoride elution) and a specific activity of 39.0 ± 12.4 Ci μmol(-1) within 77 ± 4 min.

  2. Monitoring of anti-cancer treatment with 18F-FDG and 18F-FLT PET: a comprehensive review of pre-clinical studies

    PubMed Central

    Jensen, Mette Munk; Kjaer, Andreas

    2015-01-01

    Functional imaging of solid tumors with positron emission tomography (PET) imaging is an evolving field with continuous development of new PET tracers and discovery of new applications for already implemented PET tracers. During treatment of cancer patients, a general challenge is to measure treatment effect early in a treatment course and by that to stratify patients into responders and non-responders. With 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG) and 3’-deoxy-3’-[18F]fluorothymidine(18F-FLT) two of the cancer hallmarks, altered energy metabolism and increased cell proliferation, can be visualized and quantified non-invasively by PET. With 18F-FDG and 18F-FLT PET changes in energy metabolism and cell proliferation can thereby be determined after initiation of cancer treatment in both clinical and pre-clinical studies in order to predict, at an early time-point, treatment response. It is hypothesized that decreases in glycolysis and cell proliferation may occur in tumors that are sensitive to the applied cancer therapeutics and that tumors that are resistant to treatment will show unchanged glucose metabolism and cell proliferation. Whether 18F-FDG and/or 18F-FLT PET can be used for prediction of treatment response has been analyzed in many studies both following treatment with conventional chemotherapeutic agents but also following treatment with different targeted therapies, e.g. monoclonal antibodies and small molecules inhibitors. The results from these studies have been most variable; in some studies early changes in 18F-FDG and 18F-FLT uptake predicted later tumor regression whereas in other studies no change in tracer uptake was observed despite the treatment being effective. The present review gives an overview of pre-clinical studies that have used 18F-FDG and/or 18F-FLT PET for response monitoring of cancer therapeutics. PMID:26550536

  3. Comparability of [(18)F]THK5317 and [(11)C]PIB blood flow proxy images with [(18)F]FDG positron emission tomography in Alzheimer's disease.

    PubMed

    Rodriguez-Vieitez, Elena; Leuzy, Antoine; Chiotis, Konstantinos; Saint-Aubert, Laure; Wall, Anders; Nordberg, Agneta

    2017-02-01

    For amyloid positron emission tomography tracers, the simplified reference tissue model derived ratio of influx rate in target relative to reference region (R1) has been shown to serve as a marker of brain perfusion, and, due to the strong coupling between perfusion and metabolism, as a proxy for glucose metabolism. In the present study, 11 prodromal Alzheimer's disease and nine Alzheimer's disease dementia patients underwent [(18)F]THK5317, carbon-11 Pittsburgh Compound-B ([(11)C]PIB), and 2-deoxy-2-[(18)F]fluoro-D-glucose ([(18)F]FDG) positron emission tomography to assess the possible use of early-phase [(18)F]THK5317 and R1 as proxies for brain perfusion, and thus, for glucose metabolism. Discriminative performance (prodromal vs Alzheimer's disease dementia) of [(18)F]THK5317 (early-phase SUVr and R1) was compared with that of [(11)C]PIB (early-phase SUVr and R1) and [(18)F]FDG. Strong positive correlations were found between [(18)F]THK5317 (early-phase, R1) and [(18)F]FDG, particularly in frontal and temporoparietal regions. Differences in correlations between early-phase and R1 ([(18)F]THK5317 and [(11)C]PIB) and [(18)F]FDG, were not statistically significant, nor were differences in area under the curve values in the discriminative analysis. Our findings suggest that early-phase [(18)F]THK5317 and R1 provide information on brain perfusion, closely related to glucose metabolism. As such, a single positron emission tomography study with [(18)F]THK5317 may provide information about both tau pathology and brain perfusion in Alzheimer's disease, with potential clinical applications.

  4. Monitoring of anti-cancer treatment with (18)F-FDG and (18)F-FLT PET: a comprehensive review of pre-clinical studies.

    PubMed

    Jensen, Mette Munk; Kjaer, Andreas

    2015-01-01

    Functional imaging of solid tumors with positron emission tomography (PET) imaging is an evolving field with continuous development of new PET tracers and discovery of new applications for already implemented PET tracers. During treatment of cancer patients, a general challenge is to measure treatment effect early in a treatment course and by that to stratify patients into responders and non-responders. With 2-deoxy-2-[(18)F]fluoro-D-glucose ((18)F-FDG) and 3'-deoxy-3'-[(18)F]fluorothymidine((18)F-FLT) two of the cancer hallmarks, altered energy metabolism and increased cell proliferation, can be visualized and quantified non-invasively by PET. With (18)F-FDG and (18)F-FLT PET changes in energy metabolism and cell proliferation can thereby be determined after initiation of cancer treatment in both clinical and pre-clinical studies in order to predict, at an early time-point, treatment response. It is hypothesized that decreases in glycolysis and cell proliferation may occur in tumors that are sensitive to the applied cancer therapeutics and that tumors that are resistant to treatment will show unchanged glucose metabolism and cell proliferation. Whether (18)F-FDG and/or (18)F-FLT PET can be used for prediction of treatment response has been analyzed in many studies both following treatment with conventional chemotherapeutic agents but also following treatment with different targeted therapies, e.g. monoclonal antibodies and small molecules inhibitors. The results from these studies have been most variable; in some studies early changes in (18)F-FDG and (18)F-FLT uptake predicted later tumor regression whereas in other studies no change in tracer uptake was observed despite the treatment being effective. The present review gives an overview of pre-clinical studies that have used (18)F-FDG and/or (18)F-FLT PET for response monitoring of cancer therapeutics.

  5. A new NIST primary standardization of 18F.

    PubMed

    Fitzgerald, R; Zimmerman, B E; Bergeron, D E; Cessna, J C; Pibida, L; Moreira, D S

    2014-02-01

    A new primary standardization of (18)F by NIST is reported. The standard is based on live-timed beta-gamma anticoincidence counting with confirmatory measurements by three other methods: (i) liquid scintillation (LS) counting using CIEMAT/NIST (3)H efficiency tracing; (ii) triple-to-double coincidence ratio (TDCR) counting; and (iii) NaI integral counting and HPGe γ-ray spectrometry. The results are reported as calibration factors for NIST-maintained ionization chambers (including some "dose calibrators"). The LS-based methods reveal evidence for cocktail instability for one LS cocktail. Using an ionization chamber to link this work with previous NIST results, the new value differs from the previous reports by about 4%, but appears to be in good agreement with the key comparison reference value (KCRV) of 2005. © 2013 Published by Elsevier Ltd.

  6. STATISTICAL ANALYSIS OF TANK 18F FLOOR SAMPLE RESULTS

    SciTech Connect

    Harris, S.

    2010-09-02

    Representative sampling has been completed for characterization of the residual material on the floor of Tank 18F as per the statistical sampling plan developed by Shine [1]. Samples from eight locations have been obtained from the tank floor and two of the samples were archived as a contingency. Six samples, referred to in this report as the current scrape samples, have been submitted to and analyzed by SRNL [2]. This report contains the statistical analysis of the floor sample analytical results to determine if further data are needed to reduce uncertainty. Included are comparisons with the prior Mantis samples results [3] to determine if they can be pooled with the current scrape samples to estimate the upper 95% confidence limits (UCL{sub 95%}) for concentration. Statistical analysis revealed that the Mantis and current scrape sample results are not compatible. Therefore, the Mantis sample results were not used to support the quantification of analytes in the residual material. Significant spatial variability among the current sample results was not found. Constituent concentrations were similar between the North and South hemispheres as well as between the inner and outer regions of the tank floor. The current scrape sample results from all six samples fall within their 3-sigma limits. In view of the results from numerous statistical tests, the data were pooled from all six current scrape samples. As such, an adequate sample size was provided for quantification of the residual material on the floor of Tank 18F. The uncertainty is quantified in this report by an upper 95% confidence limit (UCL{sub 95%}) on each analyte concentration. The uncertainty in analyte concentration was calculated as a function of the number of samples, the average, and the standard deviation of the analytical results. The UCL{sub 95%} was based entirely on the six current scrape sample results (each averaged across three analytical determinations).

  7. Synthesis and bioevaluation of [18F]4-fluoro-m-hydroxyphenethylguanidine ([18F]4F-MHPG): a novel radiotracer for quantitative PET studies of cardiac sympathetic innervation

    PubMed Central

    Jang, Keun Sam; Jung, Yong-Woon; Sherman, Phillip S.; Quesada, Carole A.; Gu, Guie; Raffel, David M.

    2013-01-01

    A new cardiac sympathetic nerve imaging agent, [18F]4-fluoro-m-hydroxyphenethylguanidine ([18F]4F-MHPG), was synthesized and evaluated. The radiosynthetic intermediate [18F]4-fluoro-m-tyramine ([18F]4F-MTA) was prepared and then sequentially reacted with cyanogen bromide and NH4Br/NH4OH to afford [18F]4F-MHPG. Initial bioevaluations of [18F]4F-MHPG (biodistribution studies in rats and kinetic studies in the isolated rat heart) were similar to results previously reported for the carbon-11 labeled analog [11C]4F-MHPG. The neuronal uptake rate of [18F]4F-MHPG into the isolated rat heart was 0.68 ml/min/g wet and its retention time in sympathetic neurons was very long (T1/2 > 13 h). A PET imaging study in a nonhuman primate with [18F]4F-MHPG provided high quality images of the heart, with heart-to-blood ratios at 80–90 min after injection of 5-to-1. These initial kinetic and imaging studies of [18F]4F-MHPG suggest that this radiotracer may allow for more accurate quantification of regional cardiac sympathetic nerve density than is currently possible with existing neuronal imaging agents. PMID:23416009

  8. Optimization of the ion chromatographic quantification of airborne fluoride, acetate and formate in the Metropolitan Museum of Art, New York.

    PubMed

    Kontozova-Deutsch, Velichka; Deutsch, Felix; Bencs, László; Krata, Agnieszka; Van Grieken, René; De Wael, Karolien

    2011-10-30

    Ion chromatographic (IC) methods have been compared in order to achieve an optimal separation of fluoride, acetate and formate under various elution conditions on two formerly introduced analytical columns (i and ii) and a novel one (iii): (i) an IonPac AS14 (250 mm × 4 mm I.D.), (ii) Allsep A-2 (150 mm × 4.6mm I.D.), and (iii) an IC SI-50 4E (250 mm (length) × 4mm (internal diameter - I.D.)). The IC conditions for the separation of the anions concerned were optimized on the IC SI-50 4E column. A near baseline separation of these anions was attained on the IonPac AS14, whereas the peaks of fluoride and acetate could not be resolved on the Allsep A-2. A baseline separation for the three anions was achieved on the IC SI-50 4E column, when applying an eluent mixture of 3.2 mmol/L Na(2)CO(3) and 1.0 mmol/L NaHCO(3) with a flow rate of 1.0 mL/min. The highest precision of 1.7, 3.0 and 2.8% and the best limits of detection (LODs) of 0.014, 0.22 and 0.17 mg/L for fluoride, acetate and formate, respectively, were obtained with the IC SI-50 4E column. Hence, this column was applied for the determination of the acetic and formic acid contents of air samples taken by means of passive gaseous sampling at the Metropolitan Museum of Art in New York, USA. Atmospheric concentrations of acetic and formic acid up to 1050 and 450 μg/m(3), respectively, were found in non-aerated showcases of the museum. In galleries and outdoors, rather low levels of acetic and formic acid were detected with average concentrations of 50 and 10 μg/m(3), respectively. The LOD data of acetate and formate on the IC SI-50 4E column correspond to around 0.5 μg/m(3) for both acetic and formic acid in air samples.

  9. Perspectives on Li and transition metal fluoride phosphates as cathode materials for a new generation of Li-ion batteries

    PubMed Central

    Antipov, Evgeny V.; Khasanova, Nellie R.; Fedotov, Stanislav S.

    2015-01-01

    To satisfy the needs of rapidly growing applications, Li-ion batteries require further significant improvements of their key properties: specific energy and power, cyclability, safety and costs. The first generation of cathode materials for Li-ion batteries based on mixed oxides with either spinel or rock-salt derivatives has already been widely commercialized, but the potential to improve the performance of these materials further is almost exhausted. Li and transition metal inorganic compounds containing different polyanions are now considered as the most promising cathode materials for the next generation of Li-ion batteries. Further advances in cathode materials are considered to lie in combining different anions [such as (XO4)n− and F−] in the anion sublattice, which is expected to enhance the specific energy and power of these materials. This review focuses on recent advances related to the new class of cathode materials for Li-ion batteries containing phosphate and fluoride anions. Special attention is given to their crystal structures and the relationships between structure and properties, which are important for their possible practical applications. PMID:25610630

  10. Interaction of slow highly charged ions with hard dental tissue: studies of fluoride uptake and reminalization efficacy

    NASA Astrophysics Data System (ADS)

    Daskalova, A.; Kasperski, G.; Rousseau, P.; Domaracka, A.; Lawicki, A.

    2014-05-01

    TOF-SIMS mass spectroscopy data are presented on ion irradiation of hard dental tissue using a beam of 129Xe20+ (15 kV) ions delivered in the ARIBE facility by an ECR source. The investigation was focused on the mass distribution of the fragment ions. A comparison is made between the mass spectra from hard dental tissue treated by olaflur-(C27H60F2N2O3) and untreated hard dental tissue obtained under irradiation by low-energy highly-charged ions (HCIs). We found significant differences between the mass spectra of enamel after introducing amine fluoride (olaflur) and the mass spectra of pure untreated enamel. Further, we separated out the effects caused by radiation induced in the tooth enamel from those induced in dentin, which has not been performed before. In order to conduct a further detailed analysis, it is necessary to extend the research scope to include the influence of fluorine compounds on enamel and dentin.

  11. Perspectives on Li and transition metal fluoride phosphates as cathode materials for a new generation of Li-ion batteries.

    PubMed

    Antipov, Evgeny V; Khasanova, Nellie R; Fedotov, Stanislav S

    2015-01-01

    To satisfy the needs of rapidly growing applications, Li-ion batteries require further significant improvements of their key properties: specific energy and power, cyclability, safety and costs. The first generation of cathode materials for Li-ion batteries based on mixed oxides with either spinel or rock-salt derivatives has already been widely commercialized, but the potential to improve the performance of these materials further is almost exhausted. Li and transition metal inorganic compounds containing different polyanions are now considered as the most promising cathode materials for the next generation of Li-ion batteries. Further advances in cathode materials are considered to lie in combining different anions [such as (XO4) (n-) and F(-)] in the anion sublattice, which is expected to enhance the specific energy and power of these materials. This review focuses on recent advances related to the new class of cathode materials for Li-ion batteries containing phosphate and fluoride anions. Special attention is given to their crystal structures and the relationships between structure and properties, which are important for their possible practical applications.

  12. Preparation and characterization of poly (arylene ether isoxazole)s by fluoride ion-mediated aromatic nucleophilic displacement reactions

    NASA Technical Reports Server (NTRS)

    Herbert, C. G.; Bass, R. G.

    1994-01-01

    As part of a continuing effort to prepare novel thermally stable high-performance polymers, poly(arylene ether isoxazole)s have been prepared by fluoride ion-catalyzed aromatic nucleophilic substitution reactions with bis(trimethylsiloxyphenyl) isoxazoles and activated bisarylhalides in diphenyl sulfone. Initial investigation involving the preparation of these materials with isoxazole bisphenols and activated bisarylhalides in the presence of potassium carbonate indicated that, under reaction conditions necessary to prepare high-molecular-weight materials, the isoxazole monomer was converted to an enamino ketone. This side reaction was avoided by using fluoride as a base. However, trimethylsilyl ether derivatives of the isoxazole bisphenols were required in these polymerizations for the preparation of high-molecular-weight materials. Moderate to high inherent viscosity eta(sub inh): 0.43-0.87 dl/g) materials with good thermal stability (air: 409-477 C, helium: 435-512 C) can be prepared by the silyl ether method. Glass transition temperatures ranged from 182 to 225 C for polymers with phenyl pendants and from 170 to 214 C for those without. Molecular weight control by 2% endcapping and the incorporation of a phenyl pendant at the 4 position of the isoxazole is necessary to yield polymers soluble in polar aprotic solvents at room temperature. There is evidence, however, indicating the existence of crosslinks between the polymer chains when the silyl ether approach is utilized.

  13. Preparation and characterization of poly (arylene ether isoxazole)s by fluoride ion-mediated aromatic nucleophilic displacement reactions

    NASA Technical Reports Server (NTRS)

    Herbert, C. G.; Bass, R. G.

    1994-01-01

    As part of a continuing effort to prepare novel thermally stable high-performance polymers, poly(arylene ether isoxazole)s have been prepared by fluoride ion-catalyzed aromatic nucleophilic substitution reactions with bis(trimethylsiloxyphenyl) isoxazoles and activated bisarylhalides in diphenyl sulfone. Initial investigation involving the preparation of these materials with isoxazole bisphenols and activated bisarylhalides in the presence of potassium carbonate indicated that, under reaction conditions necessary to prepare high-molecular-weight materials, the isoxazole monomer was converted to an enamino ketone. This side reaction was avoided by using fluoride as a base. However, trimethylsilyl ether derivatives of the isoxazole bisphenols were required in these polymerizations for the preparation of high-molecular-weight materials. Moderate to high inherent viscosity eta(sub inh): 0.43-0.87 dl/g) materials with good thermal stability (air: 409-477 C, helium: 435-512 C) can be prepared by the silyl ether method. Glass transition temperatures ranged from 182 to 225 C for polymers with phenyl pendants and from 170 to 214 C for those without. Molecular weight control by 2% endcapping and the incorporation of a phenyl pendant at the 4 position of the isoxazole is necessary to yield polymers soluble in polar aprotic solvents at room temperature. There is evidence, however, indicating the existence of crosslinks between the polymer chains when the silyl ether approach is utilized.

  14. Sorption of doubly charged metal ions from ammonium fluoride solutions by KFP-23 cation-exchange resin

    SciTech Connect

    Ganyaev, V.P.; Pimneva, L.A.; Pakholkov, V.S.

    1982-10-20

    This report examines the results of a study of sorption of a number of doubly charged cations by the macroporous cation-exchange KFP-12 from 0.1 N MeF/sub 2/ solutions containing NH/sub 4/F in concentrations from 0 to 3.0 M. As the result of an investigation of the sorption, under dynamic conditions, of copper, zinc, cadmium, manganese, cobalt, and nickel ions from ammonium fluoride solutions by KFP-12 cation-exchange resin in the influence of the ionic form (H/sup +/ or NH/sub 4//sup +/) of the resin and of the NH/sub 4/F concentration on the degree of sorption and on the breakthrough capacity was established. The character of bonding and coordination of the sorbed cations with the ionic groups of the resin has been established. The possibilty of thorough purification of ammonium fluoride and (NH/sub 4/)/sub 2/BeF/sub 4/ solutions with the aid of KFP-12 resin in NH/sub 4//sup +/ form has been demonstrated. The purification co-efficients were calculated.

  15. Synthesis and Reactivity of (18)F-Labeled α,α-Difluoro-α-(aryloxy)acetic Acids.

    PubMed

    Khotavivattana, Tanatorn; Calderwood, Samuel; Verhoog, Stefan; Pfeifer, Lukas; Preshlock, Sean; Vasdev, Neil; Collier, Thomas L; Gouverneur, Véronique

    2017-02-03

    In this work, we describe the (18)F-labeling of α,α-difluoro-α-(aryloxy)acetic acid derivatives and demonstrate that these building blocks are amenable to post-(18)F-fluorination functionalization. Protodecarboxylation offers a new entry to (18)F-difluoromethoxyarene, and the value of this approach is further demonstrated with coupling processes leading to representative (18)F-labeled TRPV1 inhibitors and TRPV1 antagonists.

  16. A Novel Method for Direct site-specific Radiolabeling of Peptides Using [18F]FDG

    PubMed Central

    Namavari, Mohammad; Cheng, Zhen; Zhang, Rong; De, Abhijit; Levi, Jelena; Hoerner, Joshua K.; Yaghoubi, Shahriar S.; Syud, Faisal A.; Gambhir, Sanjiv S.

    2009-01-01

    We have used the well-accepted and easily available 2-[18F]Fluoro-2-deoxyglucose ([18F]FDG) positron emission tomography (PET) tracer as a prosthetic group for synthesis of 18F-labeled peptides. We herein report the synthesis of [18F]FDG-RGD (18F labeled linear RGD) and [18F]FDG-cyclo(RGDDYK) (18F labeled cyclic RGD) as examples of the use of [18F]FDG. We have successfully prepared [18F]FDG-RGD and [18F]FDG-cyclo(RGDDYK) in 27.5% and 41% radiochemical yields (decay corrected) respectively. The receptor binding affinity study of FDG-cyclo(RGDDYK) for integrin αvβ3 , using αvβ3 positive U87MG cells confirmed a competitive displacement with 125I-echistatin as a radioligand. The IC50 value for FDG-cyclo(RGDDYK) was determined to be 0.67 ± 0.19µM. High contrast small animal PET images with relatively moderate tumor uptake were observed for [18F]FDG-RGD and [18F]FDG-cyclo(RGDDYK) as PET probes in xenografts models expressing αvβ3 integrin. In conclusion, we have successfully used [18F]FDG as a prosthetic group to prepare 18F]FDG-RGD and [18F]FDG-cyclic[RGDDYK] based on a simple one step radiosynthesis. The one step radiosynthesis methodology consists of chemoselective oxime formation between an aminooxy functionalized peptide and [18F]FDG. The results have implications for radiolabeling of other macromolecules and would lead to a very simple strategy for routine pre-clinical and clinical use. PMID:19226160

  17. Longitudinal Characterization of [18F]-FDG and [18F]-AV45 Uptake in the Double Transgenic TASTPM Mouse Model

    PubMed Central

    Waldron, Ann-Marie; wyffels, Leonie; Verhaeghe, Jeroen; Richardson, Jill C.; Schmidt, Mark; Stroobants, Sigrid; Langlois, Xavier; Staelens, Steven

    2016-01-01

    We aimed to monitor the timing of amyloid-β deposition in relation to changes in brain function using in vivo imaging with [18F]-AV45 and [18F]-FDG in a mouse model of Alzheimer’s disease. TASTPM transgenic mice and wild-type controls were scanned longitudinally with [18F]-AV45 and [18F]-FDG before (3 months of age) and at multiple time points after the onset of amyloid deposition (6, 9, 12, and 15 months of age). As expected with increasing amyloidosis, TASTPM mice demonstrated progressive age-dependent increases in [18F]-AV45 uptake that were significantly higher than for WT from 9 months onwards and correlated to ex vivo measures of amyloid burden. The metabolism of [18F]-AV45 produces several brain penetrant radiometabolites and normalization to a reference region helps to negate this non-specific binding and improve the sensitivity of [18F]-AV45. The observed trajectory of [18F]-FDG alterations deviated from our proposed hypothesis of gradual decreases with worsening amyloidosis. While [18F]-FDG uptake in TASTPM mice was significantly lower than that of WT at 9 months, reduced [18F]-FDG was not associated with aging in TASTPM mice. Moreover, [18F]-FDG uptake did not correlate to measures of ex vivo amyloid burden. Our findings suggest that while amyloid-β is sufficient to induce hypometabolism, these pathologies are not linked in a dose-dependent manner in TASTPM mice. PMID:27911309

  18. Effect of fluoride content on ion release from cast and selective laser melting-processed Co-Cr-Mo alloys.

    PubMed

    Yang, Xu; Xiang, Nan; Wei, Bin

    2014-11-01

    Selective laser melting (SLM) alloy is gaining popularity in prosthetic dentistry. However, its biocompatibility has been of some concern because of long-term exposure to fluoride in the oral environment. The purpose of this study was to examine the effect of fluoride concentration on ion release from Co-Cr-Mo alloy specimens fabricated using either SLM or lost-wax casting when immersed in an artificial saliva solution containing fluoride. Specimens were prepared with either a SLM system for the SLM alloy or conventional lost-wax techniques for the cast alloy. The specimen surfaces were wet ground with silicon carbide paper (400, 800, and 1200 grit) and immersed in modified artificial saliva solutions, the pH of which had been adjusted to 5.0 with lactic acid and which contained NaF at concentrations of 0.00%, 0.05%, 0.1%, or 0.2%. The metal ion content of the solution was determined with an inductively coupled plasma mass spectrometer. The results were submitted to 2-way ANOVA and regression analysis (α=.05). Fluoride concentration significantly influenced the elemental ion release from both the SLM and cast alloys. The quantity of ions released increased significantly with increasing fluoride concentration. The ion release from the cast specimens was significantly greater than that from the SLM specimens. The performance of the SLM alloy in immersion tests demonstrates that this new technique is a superior choice because of its good biocompatibility. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  19. Metabolites of 6-(/sup 18/F)fluoro-L-dopa in human blood

    SciTech Connect

    Firnau, G.; Sood, S.; Chirakal, R.; Nahmias, C.; Garnett, E.S.

    1988-03-01

    The metabolites of 6-(/sup 18/F)fluoro-L-dopa in the blood plasma of healthy humans have been identified as 3-O-sulfato-6(/sup 18/F)fluoro-L-dopa, 3-O-methyl-6-(/sup 18/F)fluoro-L-dopa, 6-(/sup 18/F) fluorodopamine, and 6-(/sup 18/F)fluorohomovanillic acid. The time course of these metabolites was followed up to 2 hr. The findings have implications for the use of 6-(/sup 18/F)fluoro-L-dopa as tracer for cerebral dopamine metabolism. Despite the variety of metabolites in the peripheral blood there are only two /sup 18/F-carrying compounds, 6-(/sup 18/F)fluoro-L-dopa and 3-O-methyl-6-(/sup 18/F)fluoro-L-dopa, that can cross the blood-brain barrier. After 1 hr, the plasma concentration of 3-O-methyl-6-(/sup 18/F)fluoro-L-dopa reaches approximately 20% that of 6-(/sup 18/F)fluoro-L-dopa but the mean concentration of the O-methylated metabolite over the same interval is less than 5% that of 6-(/sup 18/F)-fluoro-L-dopa.

  20. Correlation of physical parameters during radiochemical synthesis of (18)F positron emission tomography radiopharmaceuticals.

    PubMed

    Tiwari, Anjani K; Varshney, Raunak; Kaushik, Aruna; Datta, Anupama; Singh, Lokendra; Mishra, Anil K

    2011-06-01

    Positron emission tomography is a highly specialized imaging technique using short-lived radiolabel substances to produce extremely high resolution images of the body's biological function. The (18)F(-) ion is produced via the (18)O(p,n)(18)F reaction using a silver target cell filled with 1.4 mL of enriched [(18)O] water. On a typical run, the target is irradiated for 45 minutes with 16.5 MeV protons (on target) and an average beam current of 5-45 mA. When the same reaction takes place with [(16)O] water [(13)N] Ammonia is produced as the primary product by the abstraction of hydrogen from water. This study investigated the physical parameters of medical cyclotron during the radiochemical process with induced radioactivity flux and mutual correlation of physical parameters for 16.5 MeV medical cyclotron at the INMAS Delhi, India. It is observed that by getting farther from the target, the relative number of low-energy neutrons increases while the overall flux of neutrons decreases. This is due to multiple scattering of high-energy neutrons in the walls and eventually absorption of low-energy neutrons. The other parameters are also linked with each other which are correlatable.

  1. Highly sensitive sensory materials for fluoride ions based on the dithieno[3,2-b:2',3'-d]phosphole system.

    PubMed

    Neumann, Toni; Dienes, Yvonne; Baumgartner, Thomas

    2006-02-02

    [structure: see text]. The newly developed functionalization of an unsubstituted dithieno[3,2-b:2',3'-d]phosphole at the 5,5'-positions gives access to bis(pinacoleboryl) species that can be utilized as sensory materials for fluoride ions. The fluoride-triggered response of the air- and moisture-stable boryl-functionalized dithienophosphole oxide manifests itself in the generation of a new fluorescence emission that can be detected at very low analyte concentrations (ppm) or even with the naked eye upon irradiation with UV light (366 nm).

  2. Optimization of the preparation of fluorine-18-labeled steroid receptor ligands 16alpha-[18F]fluoroestradiol (FES), [18F]fluoro furanyl norprogesterone (FFNP), and 16beta-[18F]fluoro-5alpha-dihydrotestosterone (FDHT) as radiopharmaceuticals†

    PubMed Central

    Zhou, Dong; Lin, Mai; Yasui, Norio; Al-Qahtani, Mohammed H.; Dence, Carmen S.; Schwarz, Sally; Katzenellenbogen, John A.

    2014-01-01

    Fluorine-18-labeled steroid receptor tracers, 16α-[18F]fluoroestradiol (FES), [18F]fluoro furanyl norprogesterone (FFNP), and 16β-[18F]fluoro-5α-dihydrotestosterone (FDHT), are important imaging tools for studies of breast and prostate cancers using positron emission tomography (PET). The automated production of these ligands with high specific activity (SA) as radiopharmaceuticals requires modification and optimization of the currently reported methods. [18F]FES with high SA was synthesized in over 60% radiochemical yield (RCY) at the end of synthesis (EOS) using a small amount of precursor (1) (as low as 0.3 mg) and 1 M H2SO4 for deprotection of the intermediate (2). [18F]FFNP was synthesized in up to 77% RCY at EOS using the triflate precursor (4) at room temperature or in 25% RCY using the mesylate precursor (6) at 65°C. Both methods are highly reproducible and afford high SA. [18F]FDHT was synthesized by radiofluoride incorporation at room temperature, reduction with NaBH4, and deprotection with HCl/acetone, giving [18F]FDHT in up to 75% yield (RCY). All of these methods can be easily translated to automated production. The information provided here will aid in the development of automated production of these steroid receptor tracers with high or improved yields, optimal SA, and ease of processing for research and clinical use. PMID:24861984

  3. A new adsorbent of a Ce ion-implanted metal-organic framework (MIL-96) with high-efficiency Ce utilization for removing fluoride from water.

    PubMed

    Yang, Xuan; Deng, Shuangshuang; Peng, Fumin; Luo, Tao

    2017-02-14

    A novel Ce(iii) ion-implanted aluminum-trimesic metal-organic framework (Ce-MIL-96) was synthesized for the first time via alcohol-solvent incipient wetness impregnation. Compared to previously reported Ce-contained adsorbents, the fluoride adsorption performance of the new ion-implanted metal-organic framework demonstrated much higher adsorption capacity and more efficient regeneration of Ce. In a wide pH range of 3 to 10, Ce-MIL-96 maintained constant adsorption performance for fluoride, and the residual Ce and Al in the treated solution were below the safe limits in drinking water. The maximum adsorption capacity of Ce-MIL-96 was 38.65 mg g(-1) at 298 K. Excluding the contribution of MIL-96, the maximum adsorption capacity of Ce ions was 269.75 mg g(-1), which demonstrated that the service efficiency of cerium in Ce-MIL-96 is about 6 times that in Ce2O3, nearly 10 times that in Ce-mZrp, and double that in Mn-Ce oxides. There was no significant influence on fluoride removal by Ce-MIL-96 due to the presence of chloride, nitrate, sulfate, bicarbonate or phosphate. Moreover, the adsorption capacity of Ce-MIL-96 remained at more than 70% after nine cycles of adsorption-desorption. Due to this excellent adsorption performance and its regeneration properties, Ce-MIL-96 is a promising adsorbent for the removal of fluoride from groundwater.

  4. Hopping rates and concentrations of mobile fluoride ions in Pb1-xSnxF2 solid solutions

    NASA Astrophysics Data System (ADS)

    Ahmad, Mohamad M.; Yamada, Koji

    2007-09-01

    In the present paper, the ion dynamics and relaxation of fluoride ions in Pb1-xSnxF2 (with x =0.2-0.6) solid solutions, prepared by mechanochemical milling, are studied in the conductivity formalism over wide ranges of frequencies and temperatures. The conductivity spectra of the investigated materials are analyzed by the Almond-West (AW) power-law model. The estimated values of the hopping rates and the dc conductivity of different compositions are thermally activated with almost the same activation energy. The calculated values of the concentration of mobile ions, nc, are almost independent of temperature and composition for x =0.2-0.4. The maximum value of nc is obtained for the x =0.6 sample, although it does not show the maximum conductivity. Therefore, the composition dependence of the ionic conductivity of these solid solutions could be explained based on the extracted parameters. The results presented in the current work indicate that the AW model represents a reasonable approximation of the overall frequency-dependent conductivity behavior of the investigated materials. The conductivity spectra at different temperatures for each composition are successfully scaled to a single master curve, indicating a temperature-independent relaxation mechanism. For different compositions, however, the conductivity spectra cannot be scaled properly, indicating composition-dependent relaxation dynamics.

  5. A Comparative Study of the Hypoxia PET Tracers [{sup 18}F]HX4, [{sup 18}F]FAZA, and [{sup 18}F]FMISO in a Preclinical Tumor Model

    SciTech Connect

    Peeters, Sarah G.J.A.; Zegers, Catharina M.L.; Lieuwes, Natasja G.; Elmpt, Wouter van; Eriksson, Jonas; Dongen, Guus A.M.S. van; Dubois, Ludwig; Lambin, Philippe

    2015-02-01

    Purpose: Several individual clinical and preclinical studies have shown the possibility of evaluating tumor hypoxia by using noninvasive positron emission tomography (PET). The current study compared 3 hypoxia PET tracers frequently used in the clinic, [{sup 18}F]FMISO, [{sup 18}F]FAZA, and [{sup 18}F]HX4, in a preclinical tumor model. Tracer uptake was evaluated for the optimal time point for imaging, tumor-to-blood ratios (TBR), spatial reproducibility, and sensitivity to oxygen modification. Methods and Materials: PET/computed tomography (CT) images of rhabdomyosarcoma R1-bearing WAG/Rij rats were acquired at multiple time points post injection (p.i.) with one of the hypoxia tracers. TBR values were calculated, and reproducibility was investigated by voxel-to-voxel analysis, represented as correlation coefficients (R) or Dice similarity coefficient of the high-uptake volume. Tumor oxygen modifications were induced by exposure to either carbogen/nicotinamide treatment or 7% oxygen breathing. Results: TBR was stabilized and maximal at 2 hours p.i. for [{sup 18}F]FAZA (4.0 ± 0.5) and at 3 hours p.i. for [{sup 18}F]HX4 (7.2 ± 0.7), whereas [{sup 18}F]FMISO showed a constant increasing TBR (9.0 ± 0.8 at 6 hours p.i.). High spatial reproducibility was observed by voxel-to-voxel comparisons and Dice similarity coefficient calculations on the 30% highest uptake volume for both [{sup 18}F]FMISO (R = 0.86; Dice coefficient = 0.76) and [{sup 18}F]HX4 (R = 0.76; Dice coefficient = 0.70), whereas [{sup 18}F]FAZA was less reproducible (R = 0.52; Dice coefficient = 0.49). Modifying the hypoxic fraction resulted in enhanced mean standardized uptake values for both [{sup 18}F]HX4 and [{sup 18}F]FAZA upon 7% oxygen breathing. Only [{sup 18}F]FMISO uptake was found to be reversible upon exposure to nicotinamide and carbogen. Conclusions: This study indicates that each tracer has its own strengths and, depending on the question to be answered, a different tracer can be put

  6. Improved synthesis of [(18)F]FLETT via a fully automated vacuum distillation method for [(18)F]2-fluoroethyl azide purification.

    PubMed

    Ackermann, Uwe; Plougastel, Lucie; Goh, Yit Wooi; Yeoh, Shinn Dee; Scott, Andrew M

    2014-12-01

    The synthesis of [(18)F]2-fluoroethyl azide and its subsequent click reaction with 5-ethynyl-2'-deoxyuridine (EDU) to form [(18)F]FLETT was performed using an iPhase FlexLab module. The implementation of a vacuum distillation method afforded [(18)F]2-fluoroethyl azide in 87±5.3% radiochemical yield. The use of Cu(CH3CN)4PF6 and TBTA as catalyst enabled us to fully automate the [(18)F]FLETT synthesis without the need for the operator to enter the radiation field. [(18)F]FLETT was produced in higher overall yield (41.3±6.5%) and shorter synthesis time (67min) than with our previously reported manual method (32.5±2.5% in 130min).

  7. [18F]- and [11C]-Labeled N-benzyl-isatin sulfonamide analogues as PET tracers for apoptosis: synthesis, radiolabeling mechanism, and in vivo imaging of apoptosis in Fas-treated mice

    PubMed Central

    Zhou, Dong; Chu, Wenhua; Chen, Delphine L.; Wang, Qi; Reichert, David E.; Rothfuss, Justin; D'Avignon, Andre; Welch, Michael J.; Mach, Robert H.

    2011-01-01

    Summary The radiolabeled isatin sulfonamide caspase-3 inhibitor, [18F]2 (WC-II-89), is a potential PET radiotracer for noninvasive imaging of apoptosis. The radiolabeling mechanism was studied by 13C NMR, ESI/MS, and computational calculations. It was found that the high electrophilicity of the C3 carbonyl group in the isatin ring, which served as a trap for [18F]fluoride, was responsible for the failure of the radiolabeling via nucleophilic substitution of the mesylate group in 7a by [18F]fluoride. Once treated with a strong base, 7a opened the isatin ring completely to form an isatinate intermediate 16, which lost the ability to trap [18F]fluoride, thereby allowing the displacement of the mesylate group to afford the 18F-labeled isatinate 17. [18F]17 can be converted to isatin [18F]2 efficiently under acidic conditions. The ring-opening and re-closure of the isatin ring under basic and acidic conditions were confirmed by reversed phase HPLC analysis, ESI/MS and 13C NMR studies. Computational studies of model compounds also support the above proposed mechanism. Similarly, the ring-opening and re-closure method was used successfully in the synthesis of the 11C labeled isatin sulfonamide analogue [11C]4 (WC-98). A microPET imaging study using [11C]4 in the Fas liver apoptosis model demonstrated retained activity in the target organ (liver) of the treated mice. Increased caspase-3 activation in the liver was verified by the fluorometric caspase-3 enzyme assay. Therefore, this study provides a useful method for radio-synthesis of isatin derivative radiotracers for PET and SPECT studies, and [11C]4 is a potential PET radiotracer for noninvasive imaging of apoptosis. PMID:19300818

  8. Perirenal (18)F-FDG Uptake in a Patient with a Pheochromocytoma.

    PubMed

    Park, Jihyun; Byun, Byung Hyun; Jung, Chang Won; Moon, Hansol; Chang, Kyoung Jin; Lim, Ilhan; Kim, Byung Il; Choi, Chang Woon; Lim, Sang Moo

    2014-09-01

    Increased (18)F-fluorodeoxyglucose (FDG) uptake of brown fat on (18)F-FDG positron emission tomography (PET) originating from physiological activation is a common incidental finding and is usually located in the neck, shoulder, and supraclavicular areas. We present a case of an incidental pheochromocytoma showing diffusely increased (18)F-FDG uptake in bilateral perirenal fat tissue as well as supraclavicular and paravertebral fat tissue on (18)F-FDG PET/CT. The patient had no clinical symptoms except hypertension, and a pheochromocytoma was confirmed in a postsurgical specimen. A pheochromocytoma should be considered a cause in cases of increased (18)F-FDG uptake of perirenal brown fat.

  9. 18F-Labelled Intermediates for Radiosynthesis by Modular Build-Up Reactions: Newer Developments

    PubMed Central

    Ermert, Johannes

    2014-01-01

    This brief review gives an overview of newer developments in 18F-chemistry with the focus on small 18F-labelled molecules as intermediates for modular build-up syntheses. The short half-life (<2 h) of the radionuclide requires efficient syntheses of these intermediates considering that multistep syntheses are often time consuming and characterized by a loss of yield in each reaction step. Recent examples of improved synthesis of 18F-labelled intermediates show new possibilities for no-carrier-added ring-fluorinated arenes, novel intermediates for tri[18F]fluoromethylation reactions, and 18F-fluorovinylation methods. PMID:25343144

  10. High-resolution continuum source graphite furnace molecular absorption spectrometry compared with ion chromatography for quantitative determination of dissolved fluoride in river water samples.

    PubMed

    Ley, Philip; Sturm, Manfred; Ternes, Thomas A; Meermann, Björn

    2017-10-03

    In addition to beneficial health effects, fluoride can also have adverse effects on humans, animals, and plants if the daily intake is strongly elevated. One main source of fluoride uptake is water, and thus several ordinances exist in Germany that declare permissible concentrations of fluoride in, for example, drinking water, mineral water, and landfill seepage water. Controlling the fluoride concentrations in aqueous matrices necessitate valid and fast analytical methods. In this work an alternative method for the determination of fluoride in surface waters based on high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) was applied. Fluoride detection was made possible by the formation of a diatomic molecule, GaF, and detection of characteristic molecular absorption. On HR-CS-GFMAS parameter optimization, the method was adapted to surface water sample analysis. The influence of potential main matrix constituents such as Na(+), Ca(2+), Mg(2+), and Cl(-) as well as surface water sampling/storage conditions on the molecular absorption signal of GaF was investigated. Method validation demonstrated a low limit of detection (8.1 μg L(-1)) and a low limit of quantification (26.9 μg L(-1)), both sufficient for direct river water sample analysis after 0.45-μm filtration. The optimized HR-CS-GFMAS method was applied for the analysis of real water samples from the rivers Rhine and Moselle. For method validation, samples were also analyzed by an ion chromatography (IC) method. IC and HR-CS-GFMAS results both agreed well. In comparison with IC, HR-CS-GFMAS has higher sample throughput, a lower limit of detection and a lower limit of quantification, and higher selectivity, and is a very suitable method for the analysis of dissolved fluoride in river water. Graphical abstract High-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) was applied for the quantitative analysis of dissolved

  11. Preclinical Applications of 3'-Deoxy-3'-[18F]Fluorothymidine in Oncology - A Systematic Review

    PubMed Central

    Schelhaas, Sonja; Heinzmann, Kathrin; Bollineni, Vikram R.; Kramer, Gerbrand M.; Liu, Yan; Waterton, John C.; Aboagye, Eric O.; Shields, Anthony F.; Soloviev, Dmitry; Jacobs, Andreas H.

    2017-01-01

    The positron emission tomography (PET) tracer 3'-deoxy-3'-[18F]fluorothymidine ([18F]FLT) has been proposed to measure cell proliferation non-invasively in vivo. Hence, it should provide valuable information for response assessment to tumor therapies. To date, [18F]FLT uptake has found limited use as a response biomarker in clinical trials in part because a better understanding is needed of the determinants of [18F]FLT uptake and therapy-induced changes of its retention in the tumor. In this systematic review of preclinical [18F]FLT studies, comprising 174 reports, we identify the factors governing [18F]FLT uptake in tumors, among which thymidine kinase 1 plays a primary role. The majority of publications (83 %) report that decreased [18F]FLT uptake reflects the effects of anticancer therapies. 144 times [18F]FLT uptake was related to changes in proliferation as determined by ex vivo analyses. Of these approaches, 77 % describe a positive relation, implying a good concordance of tracer accumulation and tumor biology. These preclinical data indicate that [18F]FLT uptake holds promise as an imaging biomarker for response assessment in clinical studies. Understanding of the parameters which influence cellular [18F]FLT uptake and retention as well as the mechanism of changes induced by therapy is essential for successful implementation of this PET tracer. Hence, our systematic review provides the background for the use of [18F]FLT in future clinical studies. PMID:28042315

  12. A Pilot Study of 18F-FLT PET/CT in Pediatric Lymphoma.

    PubMed

    Costantini, Danny L; Vali, Reza; McQuattie, Susan; Chan, Jeffrey; Punnett, Angela; Weitzman, Shiela; Shammas, Amer; Charron, Martin

    2016-01-01

    We performed an observational pilot study of 18F-FLT PET/CT in pediatric lymphoma. Eight patients with equivocal 18F-FDG PET/CT underwent imaging with 18F-FLT PET/CT. No immediate adverse reactions to 18F-FLT were observed. Compared to 18F-FDG, 18F-FLT uptake was significantly higher in bone marrow and liver (18F-FLT SUV 8.6 ± 0.6 and 5.0 ± 0.3, versus 18F-FDG SUV 1.9 ± 0.1 and 3.4 ± 0.7, resp., p < 0.05). In total, 15 lesions were evaluated with average 18F-FDG and 18F-FLT SUVs of 2.6 ± 0.1 and 2.0 ± 0.4, respectively. Nonspecific uptake in reactive lymph nodes and thymus was observed. Future studies to assess the clinical utility of 18F-FLT PET/CT in pediatric lymphoma are planned.

  13. [Extension study and evaluation of the therapeutic response in a patient with metastatic lung adenocarcinoma using sequential study with ¹⁸F-FDG PET-CT and ¹⁸F-fluoride PET-CT].

    PubMed

    Moragas, M; Soler, M; Riera, E; García, J R

    2015-01-01

    We report a case of a patient with lung adenocarcinoma and bone and extraosseus metastases studied with (18)F-FDG PET-CT, (99m)Tc-HMDP and (18)F-fluoride PET-CT. It assesses the usefulness of (18)F-FDG PET-CT for initial staging of the disease and monitoring response to therapy. For the study of the sclerotic bone metastases it shows the superiority of 99mTc-HMDP bone scintigraphy and (18)F-fluoride PET-CT over (18)F-FDG PET-CT, and (18)F-fluoride PET-CT over bone scintigraphy. It also shows the usefulness of (18)F-fluoride PET-CT for monitoring the bone metastases.

  14. Interaction between nuclear graphite and molten fluoride salts: a synchrotron radiation study of the substitution of graphitic hydrogen by fluoride ion.

    PubMed

    Yang, Xinmei; Feng, Shanglei; Zhou, Xingtai; Xu, Hongjie; Sham, T K

    2012-01-26

    The interaction between nuclear graphite and molten fluoride salts (46.5 mol % LiF/11.5 mol % NaF/42 mol % KF) is investigated by synchrotron X-ray diffraction and C K-edge X-ray absorption near-edge structure (XANES). It is found that there are a large number of H atoms in IG-110 nuclear graphite, which is attributed to the residual C-H bond after the graphitization process of petroleum coke and pitch binder. The elastic recoil detection analysis indicates that H atoms are uniformly distributed in IG-110 nuclear graphite, in excellent agreement with the XANES results. The XANES results indicate that the immersion in molten fluoride salts at 500 °C led to H atoms in nuclear graphite partly substituted by the fluorine from fluoride salts to form C-F bond. The implications of these findings are discussed.

  15. A video-based tracking analysis to assess the chronic toxic effects of fluoride ion on the aquatic snail Potamopyrgus antipodarum (Hydrobiidae, Mollusca).

    PubMed

    Alonso, Álvaro; Camargo, Julio A

    2012-07-01

    Short-term lethal bioassays are not suited for assessing the real effects of pollutants in natural ecosystems, as their concentrations are usually unrealistic under an ecological point of view. By contrast, chronic bioassays are more realistic for assessing effects on aquatic animals, especially when behavioural endpoints are used. These endpoints are a good link between physiological and ecological effects. Among behavioural bioassays, those based on automated image analysis following video-recording have the advantage of being quantitative and non-subjective tests. The present study focuses on the assessment of chronic (63 days) effects of fluoride ion (F⁻) on the survival, proportion of affected animals (dead plus immobile animals) and several behavioural endpoints (monitored by video-recording and image analysis system) of the aquatic snail Potamopyrgus antipodarum (Hydrobiidae, Mollusca). The bioassay consisted of one control and three actual fluoride concentrations (4.68, 18.6, and 37.1 mg F⁻/L) with 12 replicates in each treatment. The endpoints were monitored every 7 day of continuous exposure to fluoride ion. The highest fluoride concentrations killed all animals at the end of the bioassay. By contrast no animals died in the lowest fluoride treatment, but snails showed several alterations of behaviour: increase heterogeneity of velocity among successive recording periods, increase of the time to escape from a marked circle, and reduction of the heterogeneity in the utilization of space. Therefore, most of the behavioural endpoints were sensitive to environmentally realistic non-lethal fluoride concentrations, being useful parameters for ecological risk assessment. The ecological relevance of these findings is discussed.

  16. Eukaryotic resistance to fluoride toxicity mediated by a widespread family of fluoride export proteins

    PubMed Central

    Li, Sanshu; Smith, Kathryn D.; Davis, Jared H.; Gordon, Patricia B.; Breaker, Ronald R.; Strobel, Scott A.

    2013-01-01

    Fluorine is an abundant element and is toxic to organisms from bacteria to humans, but the mechanisms by which eukaryotes resist fluoride toxicity are unknown. The Escherichia coli gene crcB was recently shown to be regulated by a fluoride-responsive riboswitch, implicating it in fluoride response. There are >8,000 crcB homologs across all domains of life, indicating that it has an important role in biology. Here we demonstrate that eukaryotic homologs [renamed FEX (fluoride exporter)] function in fluoride export. FEX KOs in three eukaryotic model organisms, Neurospora crassa, Saccharomyces cerevisiae, and Candida albicans, are highly sensitized to fluoride (>200-fold) but not to other halides. Some of these KO strains are unable to grow in fluoride concentrations found in tap water. Using the radioactive isotope of fluoride, 18F, we developed an assay to measure the intracellular fluoride concentration and show that the FEX deletion strains accumulate fluoride in excess of the external concentration, providing direct evidence of FEX function in fluoride efflux. In addition, they are more sensitive to lower pH in the presence of fluoride. These results demonstrate that eukaryotic FEX genes encode a previously unrecognized class of fluoride exporter necessary for survival in standard environmental conditions. PMID:24173035

  17. Eukaryotic resistance to fluoride toxicity mediated by a widespread family of fluoride export proteins.

    PubMed

    Li, Sanshu; Smith, Kathryn D; Davis, Jared H; Gordon, Patricia B; Breaker, Ronald R; Strobel, Scott A

    2013-11-19

    Fluorine is an abundant element and is toxic to organisms from bacteria to humans, but the mechanisms by which eukaryotes resist fluoride toxicity are unknown. The Escherichia coli gene crcB was recently shown to be regulated by a fluoride-responsive riboswitch, implicating it in fluoride response. There are >8,000 crcB homologs across all domains of life, indicating that it has an important role in biology. Here we demonstrate that eukaryotic homologs [renamed FEX (fluoride exporter)] function in fluoride export. FEX KOs in three eukaryotic model organisms, Neurospora crassa, Saccharomyces cerevisiae, and Candida albicans, are highly sensitized to fluoride (>200-fold) but not to other halides. Some of these KO strains are unable to grow in fluoride concentrations found in tap water. Using the radioactive isotope of fluoride, (18)F, we developed an assay to measure the intracellular fluoride concentration and show that the FEX deletion strains accumulate fluoride in excess of the external concentration, providing direct evidence of FEX function in fluoride efflux. In addition, they are more sensitive to lower pH in the presence of fluoride. These results demonstrate that eukaryotic FEX genes encode a previously unrecognized class of fluoride exporter necessary for survival in standard environmental conditions.

  18. Chemometrics-assisted kinetic-potentiometric methods for simultaneous determination of Fe(II), Al(III), and Zr(IV) using a fluoride ion-selective electrode.

    PubMed

    Karimi, Mohammad Ali; Ardakani, Mohammad Mazloum; Ardakani, Reza Behjatmanesh; Mashhadizadeh, Mohammad Hossein; Monfared, Mohammad Reza Zand; Tadayon, Maryam

    2010-01-01

    Partial least-squares (PLS) and principal component regression (PCR) were used for the simple, accurate, and simultaneous determination of Fe(III), Al(III), and Zr(IV) using the kinetic data from a novel potentiometric method. The complex forming reaction rate of Fe(III), Al(III), and Zr(IV) with fluoride ions was monitored by a fluoride ion-selective electrode. The experimental data showed the good ability of ion-selective electrodes as detectors, not only for the direct determination of fluoride ion, but also for simultaneous kinetic-potentiometric analysis using the PLS and PCR methods. The methods are based on the differences observed in the complexation rate of fluoride ions. Results have demonstrated that the simultaneous determination of Fe(III), Al(III), and Zr(IV) can be performed in concentration ranges of 0.5-18.5, 0.2-14.0, and 0.4-21.0 microg/mL, respectively. After the application of PLS, the total root mean square error of prediction (RMSEP) was found to be 0.121, 0.122, and 0.129 for the 10-sample experiment of Fe(III), Al(III), and Zr(IV), respectively. For PCR, the RMSEP was found to be 0.156, 0.162, and 0.178 for the 10-sample experiment of Fe(III), Al(III), and Zr(IV), respectively. The effects of certain foreign ions upon the reaction rate were determined for assessing the selectivity of the method. The proposed methods (H-point standard addition, PLS, and PCR) were evaluated using a set of synthetic sample mixtures, and applied for the simultaneous determination of Fe(III), Al(III), and Zr(IV) in water samples.

  19. Impact on estrogen receptor binding and target tissue uptake of [18F]fluorine substitution at the 16alpha-position of fulvestrant (faslodex; ICI 182,780).

    PubMed

    Seimbille, Yann; Bénard, François; Rousseau, Jacques; Pepin, Emilie; Aliaga, Antonio; Tessier, Guillaume; van Lier, Johan E

    2004-08-01

    Fulvestrant (Faslodex; ICI 182,780) is a pure estrogen receptor (ER) antagonist recently approved for the treatment of hormone-sensitive breast cancer in post-menopausal women with disease progression following antiestrogen therapy. Fulvestrant strongly binds to the ER and its mode of action consists of inhibition of ER dimerization leading to a down regulation of ER protein cellular levels. With the aim to develop a probe for positron emission tomography (PET) imaging capable of predicting the potential therapeutic efficacy of selective ER modulators (SERM), we prepared three new 16alpha-[18F]fluoro-fulvestrant derivatives. These new radiopharmaceuticals were evaluated for their binding affinity to the human ERalpha and for their target tissue uptake in immature female rats. Substitution of one of the side-chain F-atoms of fulvestrant for 18F would have led to a product of low specific activity; instead we selected the 16alpha-position for 18F-labeling, which at least in the case of estradiol (ES) is well tolerated by the ER. Radiochemical synthesis proceeds by stereoselective introduction of the [18F]fluoride at the 16-18F-position of fulvestrant via opening of an intermediate O-cyclic sulfate followed by hydrolysis of the protecting methoxymethyl (MOM) ether and sulfate groups. Three analogs with different oxidation states of the side chain sulfur, i.e. sulfide, sulfone or sulfoxide (fulvestrant) were prepared. Introduction of the 16(18)F-fluorine led to a dramatic decrease of the apparent binding affinity for ER, as reported by Wakeling et al. (Cancer Res. 1991;51:3867-73). Likewise, in vivo ER-mediated uterus uptake values in immature female rats were disappointing. Overall, our findings suggest that these new PET radiopharmaceuticals are not suitable as tracers to predict ER(+) breast cancer response to hormonal therapy with selective ER modulators. Copyright 2004 Elsevier Inc.

  20. Ability of (18)F-DOPA PET/CT and fused (18)F-DOPA PET/MRI to assess striatal involvement in paediatric glioma.

    PubMed

    Morana, Giovanni; Puntoni, Matteo; Garrè, Maria Luisa; Massollo, Michela; Lopci, Egesta; Naseri, Merhdad; Severino, Mariasavina; Tortora, Domenico; Rossi, Andrea; Piccardo, Arnoldo

    2016-08-01

    To assess the diagnostic performance of (18)F-DOPA PET/CT and fused (18)F-DOPA PET/MRI in detecting striatal involvement in children with gliomas. This retrospective study included 28 paediatric patients referred to our institution for the presence of primary, residual or recurrent glioma (12 boys, 16 girls; mean age 10.7 years) and investigated with (18)F-DOPA PET/CT and brain MRI. Fused (18)F-DOPA PET/MR images were obtained and compared with PET/CT and MRI images. Accuracy, sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) for striatal involvement were calculated for each diagnostic tool. Univariate and multivariate logistic analyses were applied to evaluate the associations between (18)F-DOPA PET/CT and fused (18)F-DOPA PET/MRI diagnostic results and tumour uptake outside the striatum, grade, dimension and site of striatal involvement (ventral and/or dorsal). Accuracy, sensitivity, specificity, PPV, and NPV were 100 % for MRI, 93 %, 89 %, 100 %, 100 % and 82 % for (18)F-DOPA PET/MRI, and 75 %, 74 %, 78 %, 88 % and 58 % for (18)F-DOPA PET/CT, respectively. (18)F-DOPA PET/MRI showed a trend towards higher accuracy compared with (18)F-DOPA PET/CT (p = 0.06). MRI showed significantly higher accuracy compared with (18)F-DOPA PET/CT (p = 0.01), but there was no significant difference between MRI and (18)F-DOPA PET/MRI. Both univariate and multivariate logistic analyses showed a significant association (OR 8.0 and 7.7, respectively) between the tumour-to-normal striatal uptake (T/S) ratio and the diagnostic ability of (18)F-DOPA PET/CT (p = 0.03). A strong significant association was also found between involvement of the dorsal striatum and the (18)F-DOPA PET/CT results (p = 0.001), with a perfect prediction of involvement of the dorsal striatum by (18)F-DOPA PET/MRI. Physiological striatal (18)F-DOPA uptake does not appear to be a main limitation in the evaluation of basal ganglia involvement.(18

  1. Specific, reversible binding of [18F]benperidol to baboon D2 receptors: PET evaluation of an improved 18F-labeled ligand.

    PubMed

    Moerlein, S M; Perlmutter, J S; Welch, M J

    1995-08-01

    [18F]Benperidol ([18F]BP), a positron-emitting analogue of the dopaminergic D2 antagonist benperidol, was evaluated as a radiopharmaceutical for use with positron emission tomography (PET). PET imaging of baboons after i.v. injection of [18F]BP indicated that the radiofluorinated ligand rapidly localized in vivo within dopaminergic receptor-rich cerebral tissues, and that selective disposition was retained for over 2 h. Pretreatment of an animal with unlabeled receptor-specific antagonists prior to injection of [18F]BP confirmed that the radioligand bound specifically to central D2 receptors in vivo, and not to S2 or D1 receptors. [18F]BP bound to D2 receptors in a reversible manner; unlabeled eticlopride displaced D2 receptor-bound [18F]BP in vivo. The radioligand was metabolized in the periphery to polar metabolites which are not expected to cross the blood-brain barrier. [18F]BP has advantages over other tracers as a radiopharmaceutical for PET study of central D2 receptor activity, and can be applied for noninvasive evaluation of the interaction of unlabeled drugs with central D2 receptor sites.

  2. Preparation and stability of ethanol-free solution of [18F]florbetapir ([18F]AV-45) for positron emission tomography amyloid imaging.

    PubMed

    Hayashi, Kazutaka; Tachibana, Akiko; Tazawa, Shusaku; Mizukawa, Yosuke; Osaki, Katsuhiko; Morimoto, Yoko; Zochi, Riyo; Kurahashi, Masahiro; Aki, Hatsumi; Takahashi, Kazuhiro

    2013-05-15

    We have developed an ethanol-free formulation method of [(18) F]florbetapir ([(1) (8) F]AV-45) using a commercially available automated JFE multi-purpose synthesizer. We have also evaluated the radiochemical stability in an ethanol-free solution of [(18) F]AV-45 under visible light irradiation and dark conditions by comparison with a conventional 10% ethanol solution of [(18) F]AV-45. [(18) F]AV-45 was obtained with a radiochemical yield of 55.1 ± 2.2% (decay-corrected to end of bombardment), specific activity of 591.6 ± 90.3 GBq/µmol and radiochemical purity of >99% within a total synthesis time of about 73 min. The radiochemical purity of [(18) F]AV-45 formulated by dissolving the ethanol-free solution was found to decrease as a function of the period of exposure to visible light. In contrast, the visible light photolysis could be suppressed by adding 10% ethanol to the formulation or by avoiding exposure to visible light. In the radiosynthesis of [(18) F]AV-45 formulated by dissolving the ethanol-free solution, [(18) F]AV-45 could be obtained with high radiochemical purity and high stability by avoiding exposure to visible light.

  3. Optimal Fluoridation

    PubMed Central

    Lee, John R.

    1975-01-01

    Optimal fluoridation has been defined as that fluoride exposure which confers maximal cariostasis with minimal toxicity and its values have been previously determined to be 0.5 to 1 mg per day for infants and 1 to 1.5 mg per day for an average child. Total fluoride ingestion and urine excretion were studied in Marin County, California, children in 1973 before municipal water fluoridation. Results showed fluoride exposure to be higher than anticipated and fulfilled previously accepted criteria for optimal fluoridation. Present and future water fluoridation plans need to be reevaluated in light of total environmental fluoride exposure. PMID:1130041

  4. [18F]CFT [(18F)WIN 35,428], a radioligand to study the dopamine transporter with PET: characterization in human subjects.

    PubMed

    Laakso, A; Bergman, J; Haaparanta, M; Vilkman, H; Solin, O; Hietala, J

    1998-03-01

    We have characterized the usage of [18F]CFT (also known as [18F]WIN 35,428) as a radioligand for in vivo studies of human dopamine transporter by PET. CFT was labeled with 18F to a high specific activity, and dynamic PET scans were conducted in healthy volunteers at various time points up to 5 h from [18F]CFT injection. The regional distribution of [18F]CFT uptake correlated well with the known distribution of dopaminergic nerve terminals in the human brain and also with that of other dopamine transporter radioligands. Striatal binding peaked at 225 min after injection and declined thereafter, demonstrating the reversible nature of the binding to the dopamine transporter. Therefore, due to the relatively long half-life of 18F (109.8 min), PET scans with [18F]CFT could easily be conducted during the binding equilibrium, allowing estimation of Bmax/Kd values (i.e., binding potential). Binding potentials for putamen and caudate measured at equilibrium were 4.79+/-0.11 and 4.50+/-0.23, respectively. We were able to also visualize midbrain dopaminergic neurons (substantia nigra) with [18F]CFT in some subjects. In conclusion, the labeling of CFT with 18F allows PET scans to be conducted at binding equilibrium, and therefore a high signal-to-noise ratio and reliable quantification of binding potential can be achieved. With a high resolution 3D PET scanner, the quantification of extrastriatal dopamine transporters should become possible.

  5. Aqueous Glycosylation of Unprotected Sucrose Employing Glycosyl Fluorides in the Presence of Calcium Ion and Trimethylamine

    PubMed Central

    Pelletier, Guillaume; Zwicker, Aaron; Allen, C. Liana; Schepartz, Alanna; Miller, Scott J.

    2016-01-01

    We report a synthetic glycosylation reaction between sucrosyl acceptors and glycosyl fluoride donors to yield the derived trisaccharides. This reaction proceeds at room temperature in an aqueous solvent mixture. Calcium salts and a tertiary amine base promote the reaction with high site-selectivity for either the 3′-position or 1′-position of the fructofuranoside unit. Because non-enzymatic aqueous oligosaccharide syntheses are underdeveloped, mechanistic studies were carried out in order to identify the origin of the selectivity, which we hypothesized was related to the structure of hydroxyl group array in sucrose. The solution conformation of various mono-deoxysucrose analogs revealed the cooperative nature of the hydroxyl group in mediating both this aqueous glycosyl bond-forming reaction and the site-selectivity at the same time. PMID:26859619

  6. Rapid and efficient removal of fluoride ions from aqueous solution using a polypyrrole coated hydrous tin oxide nanocomposite.

    PubMed

    Parashar, Kamya; Ballav, Niladri; Debnath, Sushanta; Pillay, Kriveshini; Maity, Arjun

    2016-08-15

    Polypyrrole/hydrous tin oxide nanocomposites (PPy/HSnO NC 1, 2, 3, 4 and 5) were synthesized through encapsulating HSnO by the PPy via an in situ polymerization for fluoride removal. The optimized adsorbent i.e. PPy/HSnO NC 3 was characterized using FE-SEM, HR-TEM, ATR-FTIR, XRD, BET, TGA and zeta sizer. Microscopic images revealed the encapsulation of HSnO by precipitating PPy during polymerization. The FTIR and XRD studies confirmed the presence of both constituents. The BET surface area and pHpzc of the adsorbent were estimated to be 65.758m(2)/g and 7.6, respectively. The fluoride adsorption followed pseudo-second-order model and was commendably rapid. The monolayer adsorption capacity was found to be 26.16-28.99mg/g at pH 6.5±0.1. The thermodynamic parameters indicated the sorption of F(-) was spontaneous, endothermic and that physisorption occurred. The calculated activation energy (Ea∼20.05kJ/mol) provided further evidence of a physisorption mechanism. Moreover, the adsorbent performed very well over a considerably wide pH range of 3.5-8.5 and in the presence of other co-existing ions. The regeneration of the F(-) laden PPy/HSnO NC 3 showed a high desorption efficiency of 95.81% up to 3 cycles. Ground water tested results also demonstrate the potential utility of the PPy/HSnO NC as an effective adsorbent. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Bifunctional colorimetric chemosensing of fluoride and cyanide ions by nickel-POCOP pincer receptors.

    PubMed

    Salomón-Flores, María K; Bazany-Rodríguez, Iván J; Martínez-Otero, Diego; García-Eleno, Marco A; Guerra-García, Jorge J; Morales-Morales, David; Dorazco-González, Alejandro

    2017-03-08

    Three Ni(ii)-POCOP pincer complexes [NiCl{C6H2-4-OH-2,6-(OPPh2)2}], 1; [NiCl{C6H2-4-OH-2,6-(OPtBu2)2}], 2 and [NiCl{C6H2-4-OH-2,6-(OPiPr2)2}], 3 were studied as bifunctional molecular sensors for inorganic anions and acetate. In CH3CN, fluoride generates a bathochromic shift with a colorimetric change for 1-3 with a simultaneous fluorescence turn on, this optical effect is based on deprotonation of the para-hydroxy group of the POCOP ligand. On the other hand, in a neutral aqueous solution of 80 vol% CH3CN, additions of cyanide produce a distinct change of color by forming very stable complexes with the nickel-based receptors 1-3 with log Ka in the range of 4.38-5.03 M(-1) and pronounced selectivity over other common anions such as iodide, phosphate, and acetate. Additionally, bromide shows a modest spectral change and affinity, but lower than those observed for cyanide. On the basis of (1)H NMR experiments, UV-vis titrations, ESI-MS experiments, and the crystal structure of the neutral bromo complex of 1, it is proposed that the colorimetric change involves an exchange of chloride by CN(-) on the Ni(ii) atom. The Ni(ii)-based sensor 1 allows the fluorescent selective detection of fluoride with a limit of 5.66 μmol L(-1) and colorimetric sensing of cyanide in aqueous medium in the micromolar concentration range.

  8. Conductivity degradation of polyvinylidene fluoride composite binder during cycling: Measurements and simulations for lithium-ion batteries

    DOE PAGES

    Grillet, Anne M.; Humplik, Thomas; Stirrup, Emily K.; ...

    2016-07-02

    The polymer-composite binder used in lithium-ion battery electrodes must both hold the electrodes together and augment their electrical conductivity while subjected to mechanical stresses caused by active material volume changes due to lithiation and delithiation. We have discovered that cyclic mechanical stresses cause significant degradation in the binder electrical conductivity. After just 160 mechanical cycles, the conductivity of polyvinylidene fluoride (PVDF):carbon black binder dropped between 45–75%. This degradation in binder conductivity has been shown to be quite general, occurring over a range of carbon black concentrations, with and without absorbed electrolyte solvent and for different polymer manufacturers. Mechanical cycling ofmore » lithium cobalt oxide (LiCoO2) cathodes caused a similar degradation, reducing the effective electrical conductivity by 30–40%. Mesoscale simulations on a reconstructed experimental cathode geometry predicted the binder conductivity degradation will have a proportional impact on cathode electrical conductivity, in qualitative agreement with the experimental measurements. Lastly, ohmic resistance measurements were made on complete batteries. Direct comparisons between electrochemical cycling and mechanical cycling show consistent trends in the conductivity decline. This evidence supports a new mechanism for performance decline of rechargeable lithium-ion batteries during operation – electrochemically-induced mechanical stresses that degrade binder conductivity, increasing the internal resistance of the battery with cycling.« less

  9. Conductivity degradation of polyvinylidene fluoride composite binder during cycling: Measurements and simulations for lithium-ion batteries

    SciTech Connect

    Grillet, Anne M.; Humplik, Thomas; Stirrup, Emily K.; Roberts, Scott A.; Barringer, David A.; Snyder, Chelsea M.; Janvrin, Madison R.; Apblett, Christopher A.

    2016-07-02

    The polymer-composite binder used in lithium-ion battery electrodes must both hold the electrodes together and augment their electrical conductivity while subjected to mechanical stresses caused by active material volume changes due to lithiation and delithiation. We have discovered that cyclic mechanical stresses cause significant degradation in the binder electrical conductivity. After just 160 mechanical cycles, the conductivity of polyvinylidene fluoride (PVDF):carbon black binder dropped between 45–75%. This degradation in binder conductivity has been shown to be quite general, occurring over a range of carbon black concentrations, with and without absorbed electrolyte solvent and for different polymer manufacturers. Mechanical cycling of lithium cobalt oxide (LiCoO2) cathodes caused a similar degradation, reducing the effective electrical conductivity by 30–40%. Mesoscale simulations on a reconstructed experimental cathode geometry predicted the binder conductivity degradation will have a proportional impact on cathode electrical conductivity, in qualitative agreement with the experimental measurements. Lastly, ohmic resistance measurements were made on complete batteries. Direct comparisons between electrochemical cycling and mechanical cycling show consistent trends in the conductivity decline. This evidence supports a new mechanism for performance decline of rechargeable lithium-ion batteries during operation – electrochemically-induced mechanical stresses that degrade binder conductivity, increasing the internal resistance of the battery with cycling.

  10. Simultaneous determination of fluoride, chloride, sulfate, phosphate, monofluorophosphate, glycerophosphate, sorbate, and saccharin in gargles by ion chromatography.

    PubMed

    Zhang, Yan-zhen; Zhou, Yan-chun; Liu, Li; Zhu, Yan

    2007-07-01

    Simple, reliable and sensitive analytical methods to determine anticariogenic agents, preservatives, and artificial sweeteners contained in commercial gargles are necessary for evaluating their effectiveness, safety, and quality. An ion chromatography (IC) method has been described to analyze simultaneously eight anions including fluoride, chloride, sulfate, phosphate, monofluorophosphate, glycerophosphate (anticariogenic agents), sorbate (a preservative), and saccharin (an artificial sweetener) in gargles. In this IC system, we applied a mobile phased gradient elution with KOH, separation by IonPac AS18 columns, and suppressed conductivity detection. Optimized analytical conditions were further evaluated for accuracy. The relative standard deviations (RSDs) of the inter-day's retention time and peak area of all species were less than 0.938% and 8.731%, respectively, while RSDs of 5-day retention time and peak area were less than 1.265% and 8.934%, respectively. The correlation coefficients for targeted analytes ranged from 0.999 7 to 1.000 0. The spiked recoveries for the anions were 90% approximately 102.5%. We concluded that the method can be applied for comprehensive evaluation of commercial gargles.

  11. Hydrophilic poly(vinylidene fluoride) porous membrane with well connected ion transport networks for vanadium flow battery

    NASA Astrophysics Data System (ADS)

    Cao, Jingyu; Yuan, Zhizhang; Li, Xianfeng; Xu, Wanxing; Zhang, Huamin

    2015-12-01

    Hydrophilic poly(vinylidene fluoride) (PVDF) porous membranes are facilely fabricated via grafting polymerization and cross-linking reaction for vanadium flow battery (VFB) application. A solvent swelling pre-treatment is specifically carried out to introduce hydrophilic groups in the pores and on the surface, where they can form well connected ion transport networks. The modification is performed through chemical cross-linking and grafting of PVP by using potassium persulfate (K2S2O8) as a radical initiator. The effect of reaction condition on membrane morphology, hydrophilicity is characterized in detail. Meanwhile, the performance of modified membranes is detected in VFB single cell at a current density of 80 mA cm-2. It is found that more PVP is immobilized on membrane surface and in the pores with prolonging reaction time. Consequently, the membrane wetability and effective pore size change dramatically, resulting better hydrophilicity and higher ion selectivity. As a result, the VFBs assembled with these modified membranes show higher CE and overall better EE than unmodified ones. The optimized membrane shows CE of 94.4% and EE of 83.3%, which is comparable to commercial Nafion 115. Furthermore, the prepared hydrophilic PVDF membranes demonstrate excellent chemical stability through the long-term battery operation, showing great prospects in VFB applications.

  12. Simultaneous determination of fluoride, chloride, sulfate, phosphate, monofluorophosphate, glycerophosphate, sorbate, and saccharin in gargles by ion chromatography*

    PubMed Central

    Zhang, Yan-zhen; Zhou, Yan-chun; Liu, Li; Zhu, Yan

    2007-01-01

    Simple, reliable and sensitive analytical methods to determine anticariogenic agents, preservatives, and artificial sweeteners contained in commercial gargles are necessary for evaluating their effectiveness, safety, and quality. An ion chromatography (IC) method has been described to analyze simultaneously eight anions including fluoride, chloride, sulfate, phosphate, monofluorophosphate, glycerophosphate (anticariogenic agents), sorbate (a preservative), and saccharin (an artificial sweetener) in gargles. In this IC system, we applied a mobile phased gradient elution with KOH, separation by IonPac AS18 columns