Radiochemistry for Preclinical Imaging Studies
George C. Kagadis, Nancy L. Ford, Dimitrios N. Karnabatidis, George K. Loudos in Handbook of Small Animal Imaging, 2018
The nucleophilicity of [18F]F− can, however, be increased. For instance, potassium carbonate is added with potassium acting as a counter-cation to fluoride. The counter-cation can be complexed by a phase transfer catalyst such as Kryptofix. This creates the so-called naked fluoride and improves both its reactivity and solubility in the organic reaction solvent. Other phase-transfer systems can be used to modulate the strength of the base in case of sensitive labeling substrates. These [18F]F− methods may rely on potassium bicarbonate, cesium carbonate, oxalate, tetrabutylammonium bicarbonate, 18-crown-6 ether, and others. Fluoride will preferably react with the protons of water and form [18F]HF with no nucleophilic activity. Therefore, in the classical protocol, any macroscopic amount of water will have to be carefully removed by concentration with solid-phase extraction on an ion exchange resin. This is followed by an azeotropic distillation using acetonitrile. This process serves also as the foundation for the preparation of 2-deoxy-2-[18F]fluoro-d–glucose (Figure 16.15).
Corrosives
Bev-Lorraine True, Robert H. Dreisbach in Dreisbach’s HANDBOOK of POISONING, 2001
Fluorine is used in organic synthesis. Hydrogen fluoride (hydrofluoric acid) is used in the petroleum and semiconductor industries and in etching glass. Cryolite (sodium aluminum fluoride) is used in aluminum reduction and many other industrial processes. Fluoride salts are used in the prevention of dental caries and in rodenticides. A 90 g tube of fluoride toothpaste contains 67 mg of fluoride. Methyl sulfonyl fluoride is used as a fumigant.
Dental Caries: Resistance Factors — Fluorides
Lars Granath, William D. McHugh in Systematized Prevention of Oral Disease: Theory and Practice, 2019
There is evidence that pH is one of the important factors for the transport of fluoride into cells. It has been shown that the accumulation of fluoride in a strain of S. mutans was dependent on the pH gradient between the medium and the cell. The explanation was that the diffusing moiety of fluoride was HF.66
Employing in vitro metabolism to guide design of F-labelled PET probes of novel α-synuclein binding bifunctional compounds
Published in Xenobiotica, 2021
Chukwunonso K. Nwabufo, Omozojie P. Aigbogun, Kevin J.H Allen, Madeline N. Owens, Jeremy S. Lee, Christopher P. Phenix, Ed S. Krol
The MS/MS spectrum, as well as the proposed fragmentation pathway for the singly charged [M + H]+ ion of 19F-[C8-6-I] with m/z 456.32 are shown in Figure S5(A,B). The fragmentation gives rise to the major product ion at m/z 340.28 characterized by the neutral loss of indene (C9H8, 116 Da) as shown in Figure S5(B), which is very similar to the major product ion seen in the fragmentation of C8-6-I (M5A1, Figure 2(C)). We noted that the 1-aminoindan bond appears to be the weakest bond for collision-induced dissociation of 19F-[C8-6-I]. This is in contrast to our observations for 19F-[C8-6-C8] and 19F-[C8-6-N] where fragmentation is largely dominated by the loss of hydrogen fluoride (-HF, 20 Da) from the carbon-fluorine bond. The product ion at m/z 340.28 further dissociates by neutral loss of hydrogen fluoride (-HF, 20 Da) to give a product ion at m/z 320.26. A small intensity product ion at m/z 436.32 is associated with the neutral loss of hydrogen fluoride (-HF, 20 Da) from the singly charged [M + H]+ ion of 19F-[C8-6-I] (Figure S5(B)). The product ion at m/z 117.13 (2,3-dihydro-1H-inden-1-ylium (C9H9+)) is associated with neutral loss of C16H26FN5O2 (339 Da) from the singly charged [M + H]+ ion of 19F-[C8-6-I].
Fate of GdF3 nanoparticles-loaded PEGylated carbon capsules inside mice model: a step toward clinical application
Published in Nanotoxicology, 2020
Binapani Mahaling, Madhu Verma, Gargi Mishra, Surabhi Chaudhuri, Debjani Dutta, Sri Sivakumar
Tetraethyl orthosilicate (TEOS), n-octadecyltrimethoxysilane (C-18 TMS), gadolinium nitrate hexahydrate (Gd(NO3)3·6H2O), bis-amino polyethylene glycol (PEG) (6000 kDa), trypsin-EDTA, Dulbecco’s-modified eagle’s medium (DMEM), penicillin–streptomycin antibiotic, N3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), phosphate buffer saline (PBS), gelatin (from cold water fish skin), and Gadolinium (Gd) standard were purchased from Sigma-Aldrich. Sulfuric acid (H2SO4), nitric acid (HNO3), ethanol, triton X-100, dimethylformamide (DMF), and dimethyl sulfoxide (DMSO) were obtained from Merck Chemicals, India. Hydrofluoric acid (HF), and sodium fluoride (NaF) were obtained from SD. Fine Chem. Ltd, India. Ammonium fluoride (NH4F), ethylenediaminetetraacetic acid (EDTA), and oleic acid were obtained from Loba Chemie, India. Sodium chloride (NaCl), sodium hydroxide (NaOH), methanol, hydrogen peroxide (H2O2) (30% w/v in water), and aqueous ammonia (25% v/v) were purchased from Fisher Scientific. Cell ROX-Alexafluor-488 reagent and Annexin-V-Alexafluor-488 reagent were purchased from Thermo Fisher Scientific. All the above chemicals were used as received. HeLa, NIH3T3, NRK-49F, MCF-7, HepG2 and PC3 cell lines were purchased from National Center for Cell Science, Pune, India.
Menstrual attitude and social cognitive stress influence autonomic nervous system in women with premenstrual syndrome
Published in Stress, 2022
Yao Meng, Lei Chang, Lulu Hou, Renlai Zhou
As shown in Figure 4, the arithmetic task results revealed that the main effect of time in HR (F(1, 94)= 178.75, difference in means [95%CI, 8.66–11.69], p < 0.001, η2 = 0.66) was significant. The values in the task period were higher than those in the recovery period. No significant main effects were observed under the group and phase conditions (all p > 0.057). The interaction among groups and time concerning. HF during the recovery period was higher than that in the task period in the non-PMS group (F(1, 94) = 4.82, the difference in means [95%CI, 0.03–0.46], p = 0.04, η2 = 0.05). Furthermore, the interactions among three factors of HF and LF/HF were significant. During the late luteal phase, the HF of the PMS group during the recovery period was lower than that in the task period (F(1, 94) = 4.29, difference in means [CI 95%, 0.13–0.64], p = 0.04, η2 = 0.04); LF/HF in the PMS group was lower than that in the non-PMS group during task period in the late luteal phase (F(1, 94) = 5.20, the difference in means [95%CI, 0.08–1.19], p= 0.03, η2 = 0.05), but it became higher than that in the non-PMS group during the recovery period (F(1, 94) = 10.98, difference in means [95%CI, 0.73–1.96], p= 0.001, η2 = 0.11). LF was not significantly different throughout the process (all p > 0.07).
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