As many new drug substances contained various aromatic rings and fluorine attached to an electron rich aromatic ring or on the meta-position, a strategy towards improvement in aromatic fluorination of these compounds is highly desirable. The introduction of fluorine-18 onto aromatic rings showed in the limited condition containing electron withdrawing group (EWG) on the para- or ortho-position to get reasonable radiochemical yield so far. No-carrier added (NCA) [18F]fluoroarene syntheses by iodonium salts recently reported that has the potential to greatly increase the yield in systems or positions that normally not reactive enough to give sufficient yields in simple model reaction. This review describes the methodological approach towards effective aromatic fluorination by diaryliodonium salts and future prospects in an application of novel PET radiotracer.
Electrons ; Fluorine ; Halogenation ; Salts

OBJECTIVES: The purpose of this study was to compare the amount and rate of cumulative fluoride released over a period of 4 h from several varnishes marketed in Korea. METHODS: The following six commercial products were studied: cavity shield (CS, 22,600 ppm F), V varnish (VV, 22,600 ppm F), enamel pro varnish (EP, 22,600 ppm F), MI varnish (MI, 22600 ppm F), fluorine care (FC, 22600 ppm F), and fluor protector N (FP, 7700 ppm F). Five samples were collected from each varnish. Further, 10 mg of each varnish were applied onto an acrylic surface (diameter, 5 mm) and then immersed in 20 mL of distilled water at 37degrees C. The fluoride concentration in each sample was then analyzed after 30 min, 1, 2, 3, and 4 h, and after 4 days of exposure. RESULTS: The cumulative amount of fluoride released by FC (5.64+/-1.10 ppm) was significantly higher than that released by other products after 30 min. FC (8.55+/-1.85 ppm) and MI (8.21+/-0.81 ppm) released a significantly higher cumulative amount of fluoride after 4 h. The cumulative rate of fluoride released by FC (47.80+/-9.35%) was significantly higher than that of other products after 30 min. FC (72.44+/-15.68%) and MI (69.54+/-6.88%) showed a higher cumulative fluoride release rate after 4 h. MI sustainably released fluoride after 4 h and demonstrated a high fluoride release rate of 95.76%. CONCLUSIONS: The cumulative amount and rate of fluoride released by several varnishes were statistically significant at each time point. This data can be used by clinicians prior to selection of dental products.
Dental Enamel ; Fluorides* ; Fluorine ; Korea ; Paint* ; Water

This study was conducted by the Dept. of Preventive Medicine, Kyung-Hee University, School of Medicine as a preliminay test for the effects of Fluorine Compounds to the Plants from April through August, 1971. Fluorine was measured with Zirconium-Alizarine method and the following findings could be obtained : 1. Most high densities (25.7pptm) was found around the industrial areas and lowest (19.3pptm) around residential sections in Seoul. 2. Average density of Fluorine in the atmosphere of Seoul City was 22.3 pptm which can damage such plants as Pine, Strawberry, Peach and Grapes. 3. Fluorine contests (22.3pptm) in Seoul area atmosphere of shows about 4 times more than that of Cincinnati, Ohio, U.S.A.
Air Pollutants* ; Atmosphere ; Fluorine Compounds* ; Fluorine* ; Fragaria ; Humans ; Ohio ; Preventive Medicine ; Prunus persica ; Seoul ; Vitis

This study was conducted by the Dept. of Preventive Medicine, Kyung-Hee University, School of Medicine as a preliminay test for the effects of Fluorine Compounds to the Plants from April through August, 1971. Fluorine was measured with Zirconium-Alizarine method and the following findings could be obtained : 1. Most high densities (25.7pptm) was found around the industrial areas and lowest (19.3pptm) around residential sections in Seoul. 2. Average density of Fluorine in the atmosphere of Seoul City was 22.3 pptm which can damage such plants as Pine, Strawberry, Peach and Grapes. 3. Fluorine contests (22.3pptm) in Seoul area atmosphere of shows about 4 times more than that of Cincinnati, Ohio, U.S.A.
Air Pollutants* ; Atmosphere ; Fluorine Compounds* ; Fluorine* ; Fragaria ; Humans ; Ohio ; Preventive Medicine ; Prunus persica ; Seoul ; Vitis

PURPOSE: Electrophilic 18F (T1/2=110 min) radionuclide in the form of [18F]F2 gas is of great significance for labeling radiopharmaceuticals for positron emission tomography (PET). However, its production in high yield and with high specific radioactivity is still a challenge to overcome several problems on targetry. The aim of the present study was to develop a method suitable for the routine production of [18F]F2 for the electrophilic substitution reaction. MATERIALS AND METHODS: The target was designed water-cooled aluminum target chamber system with a conical bore shape. Production of the elemental fluorine was carried out via the 18O(p,n)18F reaction using a two-step irradiation protocol. In the first irradiation, the target filled with highly enriched 18O2 was irradiated with protons for 18F production, which were adsorbed on the inner surface of target body. In the second irradiation, the mixed gas (1% [19F]F2/Ar) was loaded into the target chamber, following a short irradiation of proton for isotopic exchange between the carrier-fluorine and the radiofluorine absorbed in the target chamber. Optimization of production was performed as the function of irradiation time, the beam current and 18O2 loading pressure. RESULTS: Production runs was performed under the following optimum conditions: The 1st irradiation for the nuclear reaction (15.0 bar of 97 % enriched 18O2, 13.2 MeV protons, 30 micro A, 60-90 min irradiation), the recovery of enriched oxygen via cryogenic pumping; The 2nd irradiation for the recovery of absorbed radiofluorine (12.0 bar of 1% [19F]fluorine/argon gas, 13.2 MeV protons, 30 micro A, 20-30 min irradiation), the recovery of [18F]fluorine for synthesis. The yield of [18F]fluorine at EOB (end of bombardment) was achieved around 34+/-6.0 GBq (n>10). CONCLUSION: The production of 18F electrophilic agent via 18O(p,n)18F reaction was much under investigation. Especially, an aluminum gas target was very advantageous for routine production of [18F]fluorine. These results suggest the possibility to use [18F]F2 gas as a electrophilic substitution agent.
Aluminum ; Fluorine ; Oxygen ; Positron-Emission Tomography ; Protons ; Radioactivity ; Radiopharmaceuticals

China ; Fluorine ; analysis ; toxicity ; Humans ; Neoplasms ; mortality ; Water Supply ; analysis

OBJECTIVES: This study aimed to confirm the efficacy of the urinary fluoride concentration/creatinine ratio for monitoring fluorine intake in fluoridated and non-fluoridated communities. METHODS: The correlations among the fluoride concentration in drinking water and that in the urine and fingernails of 52 preschool children (age, 60-72 months) from fluoridated and non-fluoridated communities were analyzed. RESULTS: The urinary fluoride concentration/creatinine ratio had a relatively high correlation with the fluoride concentration in drinking water (Pearson's correlation coefficient, 0.606; P<0.05). Further, this ratio was significantly positively correlated with the urinary fluoride concentration (Pearson's correlation coefficient, 0.374; P<0.01). However, there was no significant correlation between this ratio and the fluoride concentration in fingernails (Pearson's correlation coefficient, 0.145; P>0.05). CONCLUSIONS: The findings of this study suggest that the urinary fluoride concentration/creatinine ratio in children can be utilized as an index for monitoring excess fluoride intake in fluoridated communities.
Child ; Child, Preschool ; Drinking ; Drinking Water ; Fluoridation ; Fluorides ; Fluorine ; Humans ; Nails

PURPOSE: To assess the utility of 2-[18F] fluoro-2-deoxy-D-glucose (FDG) PET in differentiating malignant and benign diffuse pleural disease, and to compare it with CT. MATERIALS AND METHODS: Both FDG PET and CT scans were performed in 20 consecutive patients with diffuse pleural disease (13 malignant and seven benign cases). In FDG PET, peak standardized uptake value (SUV) as well as visual assessment of abnormally increased uptake in the pleura was evaluated. The results were compared with CT findings. RESULTS: With only visual assessment of PET images, sensitivity, specificity, and accuracy for malignancy were 92%, 43%, and 75%, respectively. With peak SUV of 4.8 or more, the corresponding figures were 100%, 57%, and 85%, respectively, and on CT interpretation, were100%, 57%, and 85%, respectively. Tuberculous empyema simulated malignant pleural disease both on FDG PET (3/6 patients with peak SUV more than 4.8) and CT (3/6 patients). CONCLUSION: For the differentiation of malignant and benign diffuse pleural disease, FDG PET and CT are equally accurate. Combined visual and quantitative assessments of PET images enhance discriminatory ability. Tuberculous empyema simulates malignant pleural disease both on FDG PET and CT.
Diagnosis, Differential* ; Empyema, Tuberculous ; Fluorine ; Humans ; Pleura ; Pleural Diseases* ; Sensitivity and Specificity ; Tomography, X-Ray Computed

Augmentation rhinoplasty is one of the most popular aesthetic procedures in Asians. Numerous alloplastic implants have been used, however alloplastic implants may cause many problems in nasal and perinasal areas because of thin soft tissue cover. For these reasons, an ideal implant should be nonpalpable, readily exchangeable and biocompatible. Among these alloplastic implants, Gore-Tex(R) is a polymer of carbon bound to fluorine composed of solid nodes connected by very fine fibers. It has been reported that this material become permeated and surrounded by mature connective tissue, forming a strong supporting envelop for the material, yet the implant is easily removed because of limited tissue ingrowth. Since it's development, Gore-Tex(R) has found many applications in the field of facial plastic and reconstructive surgery. From November, 2001 to December, 2002, Gore-Tex(R) implants were removed from 17 patients due to several problems such as; decreased dorsal height, tip deformity, chronic inflammation. The implants were very hard to remove and coinciding injury of the surrounding tissue were inevitable. An analysis of the length and thickness changes in these removed implants was made. The results showed, decrease in length and thickness with a volume loss averaging, 46.3% in 45x4.0mm implants, 49.3% in 50x5.0mm implants. In view of the experiences of 17 cases of Gore-Tex(R) implants in rhinoplasty, we have concluded that Gore-Tex(R) implants were structurally unstable, fibrovascular tissue ingrowth into pores were minimal, the implants were very hard to remove and the implants caused a postoperative volume reduction. Therefore, Gore-Tex(R) use in augmentation rhinoplasty should be approached with caution.
Asian Continental Ancestry Group ; Carbon ; Congenital Abnormalities ; Connective Tissue ; Fluorine ; Humans ; Inflammation ; Plastics ; Polymers ; Polytetrafluoroethylene* ; Rhinoplasty*

OBJECTIVETo analyze the mechanism of fluorine by systemic analysis of fluorination-demineralization-remineralization experiments.

METHODSThe enamel specimens were randomly assigned to untreated group (group A), non-fluoride group (group B), low-fluoride group (group C) and high-fluoride group (group D). The in vitro model of fluoride enamel was established in group C and D. Based on that, the establishment of demineralization model and remineralization experiment by pH-cycling in group B, C and D were followed. All enamel specimens were observed by stereomicroscope and scanning electron microscope and compared in surface microhardness value.

RESULTSThere was distinct difference in micro-morphologic appearance on fluoride enamel surface. Artificial caries of fluoride enamel showed a relatively complete surface, the surface microhardness after demineralization and remineralization in fluoride group was higher than non-fluoride group (P < 0.05).

CONCLUSIONThe fluorinated enamel can enhance cariostatic potential and remineralization capacity of dental enamel.