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  1. A review on superior advanced oxidation and photocatalytic degradation techniques for perfluorooctanoic acid (PFOA) elimination from wastewater
    Zango ZU, Khoo KS, Garba A, Kadir HA, Usman F, Zango MU, et al.
    Environ Res, 2023 Mar 15;221:115326.
    PMID: 36690243 DOI: 10.1016/j.envres.2023.115326
    Perfluorooctanoic acid (PFOA) has been identified as the most toxic specie of the family of perfluorinated carboxylic acids (PFCAs). It has been widely distributed and frequently detected in environmental wastewater. The compound's unique features such as inherent stability, rigidity, and resistance to harsh chemical and thermal conditions, due to its multiple and strong C-F bonds have resulted in its resistance to conventional wastewater remediations. Photolysis and bioremediation methods have been proven to be inefficient in their elimination, hence this article presents intensive literature studies and summarized findings reported on the application of advanced oxidation processes (AOPs) and photocatalytic degradation techniques as the best alternatives for the PFOA elimination from wastewater. Techniques of persulfate, photo-Fenton, electrochemical, photoelectrochemical and photocatalytic degradation have been explored and their mechanisms for the degradation and defluorination of the PFOA have been demonstrated. The major advantage of AOPs techniques has been centralized on the generation of active radicals such as sulfate (SO4•-) hydroxyl (•OH). While for the photocatalytic process, photogenerated species (electron (e) and holes (h + vb)) initiated the process. These active radicals and photogenerated species possessed potentiality to attack the PFOA molecule and caused the cleavage of the C-C and C-F bonds, resulting in its efficient degradation. Shorter-chain PFCAs have been identified as the major intermediates detected and the final stage entails its complete mineralization to carbon dioxide (CO2) and fluoride ion (F-). The prospects and challenges associated with the outlined techniques have been highlighted for better understanding of the subject matter for the PFOA elimination from real wastewaters.
    Matched MeSH terms: Fluorocarbons*
  2. Contamination, bioaccumulation and toxic effects of perfluorinated chemicals (PFCs) in the water environment: a review paper
    Suja F, Pramanik BK, Zain SM
    Water Sci Technol, 2009;60(6):1533-44.
    PMID: 19759456 DOI: 10.2166/wst.2009.504
    Perfluorinated compounds such as perfluorooctane sulfonate (PFOS) and perfluorooctane acid (PFOA) have been recognized as emerging environmental pollutants because of their ubiquitous occurrence in the environment, biota and humans. The paper focuses on the distribution, bioaccumulation and toxic effects of PFOS and PFOA in the water. From the available literature, tap and surface water samples in several countries were found to be contaminated with PFOS and PFOA. These compounds were detected globally in the tissues of fish, bird and marine mammals. Their concentrations from relatively more industrialized areas were greater than those from the less populated and remote locations. Blood samples of occupationally exposed people and the general population in various countries were found to contain PFOS and PFOA which suggested a possibility of atmospheric transport of these compounds. There is still a death of information about the environmental pathways of PFOS and PFOA. The presence of these compounds in the tap water, surface water and animal and human tissues indicates their global contamination and bioaccumulative phenomena in the ecosystems.
    Matched MeSH terms: Fluorocarbons/blood; Fluorocarbons/metabolism*; Fluorocarbons/toxicity*
  3. Removal of emerging perfluorooctanoic acid and perfluorooctane sulfonate contaminants from lake water
    Pramanik BK, Pramanik SK, Sarker DC, Suja F
    Environ Technol, 2017 Aug;38(15):1937-1942.
    PMID: 27666670 DOI: 10.1080/09593330.2016.1240716
    Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are the major polyfluoroalkyl substances (PFASs) contaminating global water environment. This study investigated the efficiency of granular activated carbon (GAC), ultrafiltration (UF) and nanofiltration (NF) treatment for removing PFOS and PFOA contaminants from lake water. NF gave greater removal of all contaminant types (in terms of organic matter, PFOS and PFOA) than GAC treatment which in turn was greater than UF treatment. The lower removal by UF was due to larger pore size of the membrane compared to the size of the target contaminants. For all treatment processes, lower pH (4) in the feedwater showed greater rejection of the organics and selected PFASs. This was likely due to increase in the electrostatic repulsion between solute and sorbent. It could be observed that on increasing the concentration of organics in the feed solution, the rejection of PFOA/PFOS decreased which was due to competition between organics and PFOS/PFOA for binding sites on the membrane/activated carbon surface. It was also noted that protein content led to greater influence for lower rejection of the PFOA/PFOS than carbohydrate or DOC content. This study demonstrated the potential use of membrane processes for removing emerging persistent organic pollutant removal from lake water.
    Matched MeSH terms: Fluorocarbons/chemistry*
  4. Fulltext PFOS induces behavioral alterations, including spontaneous hyperactivity that is corrected by dexamfetamine in zebrafish larvae
    Spulber S, Kilian P, Wan Ibrahim WN, Onishchenko N, Ulhaq M, Norrgren L, et al.
    PLoS One, 2014;9(4):e94227.
    PMID: 24740186 DOI: 10.1371/journal.pone.0094227
    Perfluorooctane sulfonate (PFOS) is a widely spread environmental contaminant. It accumulates in the brain and has potential neurotoxic effects. The exposure to PFOS has been associated with higher impulsivity and increased ADHD prevalence. We investigated the effects of developmental exposure to PFOS in zebrafish larvae, focusing on the modulation of activity by the dopaminergic system. We exposed zebrafish embryos to 0.1 or 1 mg/L PFOS (0.186 or 1.858 µM, respectively) and assessed swimming activity at 6 dpf. We analyzed the structure of spontaneous activity, the hyperactivity and the habituation during a brief dark period (visual motor response), and the vibrational startle response. The findings in zebrafish larvae were compared with historical data from 3 months old male mice exposed to 0.3 or 3 mg/kg/day PFOS throughout gestation. Finally, we investigated the effects of dexamfetamine on the alterations in spontaneous activity and startle response in zebrafish larvae. We found that zebrafish larvae exposed to 0.1 mg/L PFOS habituate faster than controls during a dark pulse, while the larvae exposed to 1 mg/L PFOS display a disorganized pattern of spontaneous activity and persistent hyperactivity. Similarly, mice exposed to 0.3 mg/kg/day PFOS habituated faster than controls to a new environment, while mice exposed to 3 mg/kg/day PFOS displayed more intense and disorganized spontaneous activity. Dexamfetamine partly corrected the hyperactive phenotype in zebrafish larvae. In conclusion, developmental exposure to PFOS in zebrafish induces spontaneous hyperactivity mediated by a dopaminergic deficit, which can be partially reversed by dexamfetamine in zebrafish larvae.
    Matched MeSH terms: Fluorocarbons/metabolism; Fluorocarbons/toxicity*
  5. Fulltext Short-term postoperative perfluoro-n-octane tamponade for pediatric recurrent retinal detachment
    Ling KP, Wu AL, Lai CC, Wu WC
    Taiwan J Ophthalmol, 2019 1 15;8(4):249-252.
    PMID: 30637197 DOI: 10.4103/tjo.tjo_100_18
    We report a case with multiple recurrences of retinal detachment (RD) with severe proliferative vitreoretinopathy in a 12-year-old child who underwent vitrectomy using a heavy liquid perfluoro-n-octane (PFO) as a short-term postoperative tamponade. He had an encircling band and three vitrectomies with gas, followed by silicone oil tamponade for retinal redetachment prior to the use of PFO as a short-term tamponade. Short-term PFO tamponade was used in which inferior retinal reattachment was considered to be difficult with conventional gas or silicone oil tamponade, especially in regard to proper postoperative posturing. The PFO was left in the eye for 1 week, and the retina remained reattached after removal of the PFO which was replaced with silicone oil tamponade in this case. PFO appears feasible and tolerable as a short-term postoperative tamponade in the management of complex pediatric RD.
    Matched MeSH terms: Fluorocarbons
  6. Fulltext A Green Approach to Modify Surface Properties of Polyurethane Foam for Enhanced Oil Absorption
    Ng ZC, Roslan RA, Lau WJ, Gürsoy M, Karaman M, Jullok N, et al.
    Polymers (Basel), 2020 Aug 21;12(9).
    PMID: 32825561 DOI: 10.3390/polym12091883
    The non-selective property of conventional polyurethane (PU) foam tends to lower its oil absorption efficiency. To address this issue, we modified the surface properties of PU foam using a rapid solvent-free surface functionalization approach based on the chemical vapor deposition (CVD) method to establish an extremely thin yet uniform coating layer to improve foam performance. The PU foam was respectively functionalized using different monomers, i.e., perfluorodecyl acrylate (PFDA), 2,2,3,4,4,4-hexafluorobutyl acrylate (HFBA), and hexamethyldisiloxane (HMDSO), and the effect of deposition times (1, 5 and 10 min) on the properties of foam was investigated. The results showed that all the modified foams demonstrated a much higher water contact angle (i.e., greater hydrophobicity) and greater absorption capacities compared to the control PU foam. This is due to the presence of specific functional groups, e.g., fluorine (F) and silane (Si) in the modified PU foams. Of all, the PU/PHFBAi foam exhibited the highest absorption capacities, recording 66.68, 58.15, 53.70, and 58.38 g/g for chloroform, acetone, cyclohexane, and edible oil, respectively. These values were 39.19-119.31% higher than that of control foam. The promising performance of the PU/PHFBAi foam is due to the improved surface hydrophobicity attributed to the original perfluoroalkyl moieties of the HFBA monomer. The PU/PHFBAi foam also demonstrated a much more stable absorption performance compared to the control foam when both samples were reused for up to 10 cycles. This clearly indicates the positive impact of the proposed functionalization method in improving PU properties for oil absorption processes.
    Matched MeSH terms: Fluorocarbons
  7. Fulltext Global warming: can we do something?
    Ghazally Ismail
    ASM Science Journal, 2011;5(1):73-74.
    MyJurnal
    Human activity has ‘very likely’ been the primary cause of global warming since the start of the Industrial Revolution (18th–19th century). As a new player in industrial transformation, Malaysia can choose to ignore the warnings of global warming. blame. This may not augur well. Release of greenhouse gases have been categorically linked to climate change and global warming. In her march towards industrialization, Malaysia too has contributed to the release of greenhouse gases. Apart from those arising from natural sources, the industrial sector in Malaysia also releases other types of gases such as the fluorocarbons. This is evident from the worsening air quality in some of our cities. (Copied from article).
    Matched MeSH terms: Fluorocarbons
  8. Fulltext Bilateral Giant Retinal Tear and Sequential Vitrectomy
    Mustapha M, Roufail Franzco E
    Case Rep Ophthalmol, 2017 08 17;8(2):436-439.
    PMID: 28924443 DOI: 10.1159/000479728
    PURPOSE: To describe the excellent outcome of surgery for bilateral giant retinal tears (GRTs) with better options of endotamponade.

    METHODS: This is a case report of a 62-year-old man who presented with bilateral GRTs and associated retinal detachment. The tear in the right eye was supero-temporal and silicone oil was used as an endotamponade. The tear in the left eye was infero-temporal and perfluorocarbon liquid was used as an endotamponade.

    RESULTS: The outcome at 6 months after surgery was excellent with visual acuities of 6/6 in both eyes.

    CONCLUSION: Improved availability of endotamponade agents allows repair of bilateral GRTs to be done at the same time, with good surgical outcomes.

    Matched MeSH terms: Fluorocarbons
  9. Contamination of perfluorinated compounds (PFCs) in Chao Phraya River and Bangpakong River, Thailand
    Kunacheva C, Boontanon SK, Fujii S, Tanaka S, Musirat C, Artsalee C, et al.
    Water Sci Technol, 2009;60(4):975-82.
    PMID: 19700836 DOI: 10.2166/wst.2009.462
    Perfluorinated compounds (PFCs) have been used for many years, and are distributed all over the world. This study focused on occurrences of PFCs, especially perfluorooctane sulfonate (PFOS) and perfluorooctonoic acid (PFOA) in Thai rivers and industrial estate discharges, while comparing results with rivers of other Asian countries (Japan, China, and Malaysia). Surveys were conducted in Chao Phraya River, Bangpakong River and three industrial estates. A solid phase extraction (SPE) and HPLC-ESI-MS/MS were used for the analysis of these chemicals. The average concentrations of PFOS and PFOA were 1.9 and 4.7 ng/L, respectively in Chao Phraya River, while lower concentrations were detected in Bangpakong River with the averages of 0.7 ng/L for both PFOS and PFOA. Higher concentrations were detected in all industrial estate discharges with the averages of 64.3 ng/L for PFOA and 17.9 ng/L for PFOS., Total loadings from three industrial estates were 1.93 g/d for PFOS and 11.81 g/d for PFOA. The concentration levels in Thai rivers were less than rivers in Japan, China, and Malaysia. However, PFCs loading rate of Chao Phraya River was much higher than Yodo River (Japan), due to the higher flow rate. The other six PFCs were found above the Limit of Quantification (LOQ) in most samples. PFHxS and PFNA were also highly detected in some river samples.
    Matched MeSH terms: Fluorocarbons/analysis*
  10. Perfluorinated compounds in human breast milk from several Asian countries, and in infant formula and dairy milk from the United States
    Tao L, Ma J, Kunisue T, Libelo EL, Tanabe S, Kannan K
    Environ Sci Technol, 2008 Nov 15;42(22):8597-602.
    PMID: 19068854
    The occurrence of perfluorinated compounds (PFCs) in human blood is known to be widespread; nevertheless, the sources of exposure to humans, including infants, are not well understood. In this study, breast milk collected from seven countries in Asia was analyzed (n=184) for nine PFCs, including perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA). In addition, five brands of infant formula (n=21) and 11 brands of dairy milk (n=12) collected from retail stores in the United States were analyzed, for comparison with PFC concentrations previously reported for breast milk from the U.S. PFOS was the predominant PFC detected in almost all Asian breast milk samples, followed by perfluorohexanesulfonate (PFHxS) and PFOA. Median concentrations of PFOS in breast milk from Asian countries varied significantly;the lowest concentration of 39.4 pg/mL was found in India, and the highest concentration of 196 pg/mL was found in Japan. The measured concentrations were similarto or less than the concentrations previously reported from Sweden, the United States, and Germany (median, 106-166 pg/mL). PFHxS was found in more than 70% of the samples analyzed from Japan, Malaysia, Philippines, and Vietnam, at mean concentrations ranging from 6.45 (Malaysia) to 15.8 (Philippines) pg/mL PFOA was found frequently only in samples from Japan; the mean concentration for that country was 77.7 pg/mL. None of the PFCs were detected in the infant-formula or dairy-milk samples from the U.S. except a few samples that contained concentrations close to the limit of detection. The estimated average daily intake of PFOS by infants from seven Asian countries, via breastfeeding, was 11.8 +/- 10.6 ng/kg bw/ day; this value is 7-12 times higher than the estimated adult dietary intakes previously reported from Germany, Canada, and Spain. The average daily intake of PFOA by Japanese infants was 9.6 +/- 4.9 ng/kg bw/day, a value 3-10 times greater than the estimated adult dietary intakes reported from Germany and Canada. The highest estimated daily intakes of PFOS and PFOA by infants from seven Asian countries studied were 1-2 orders of magnitude below the tolerable daily intake values recommended by the U.K. Food Standards Agency.
    Matched MeSH terms: Fluorocarbons/analysis*
  11. Anisotropic reversed micelles with fluorocarbon-hydrocarbon hybrid surfactants in supercritical CO2
    Sagisaka M, Ono S, James C, Yoshizawa A, Mohamed A, Guittard F, et al.
    Colloids Surf B Biointerfaces, 2018 Aug 01;168:201-210.
    PMID: 29276082 DOI: 10.1016/j.colsurfb.2017.12.012
    Previous work (M. Sagisaka, et al. Langmuir 31 (2015) 7479-7487), showed the most effective fluorocarbon (FC) and hydrocarbon (HC) chain lengths in the hybrid surfactants FCm-HCn (sodium 1-oxo-1-[4-(perfluoroalkyl)phenyl]alkane-2-sulfonates, where m = FC length and n = HC length) were m and n = 6 and 4 for water solubilization, whereas m 6 and n 6, or m 6 and n 5, were optimal chain lengths for reversed micelle elongation in supercritical CO2. To clarify why this difference of only a few methylene chain units is so effective at tuning the solubilizing power and reversed micelle morphology, nanostructures of water-in-CO2 (W/CO2) microemulsions were investigated by high-pressure small-angle neutron scattering (SANS) measurements at different water-to-surfactant molar ratios (W0) and surfactant concentrations. By modelling SANS profiles with cylindrical and ellipsoidal form factors, the FC6-HCn/W/CO2 microemulsions were found to increase in size with increasing W0 and surfactant concentration. Ellipsoidal cross-sectional radii of the FC6-HC4/W/CO2 microemulsion droplets increased linearly with W0, and finally reached ∼39 Å and ∼78 Å at W0 = 85 (close to the upper limit of solubilizing power). These systems appear to be the largest W/CO2 microemulsion droplets ever reported. The aqueous domains of FC6-HC6 rod-like reversed micelles increased in size by 3.5 times on increasing surfactant concentration from 35 mM to 50 mM: at 35 mM, FC6-HC5 formed rod-like reversed micelles 5.3 times larger than FC6-HC6. Interestingly, these results suggest that hybrid HC-chains partition into the microemulsion aqueous cores with the sulfonate headgroups, or at the W/CO2 interfaces, and so play important roles for tuning the W/CO2 interfacial curvature. The super-efficient W/CO2-type solubilizer FC6-HC4, and the rod-like reversed micelle forming surfactant FC6-HC5, represent the most successful cases of low fluorine content additives. These surfactants facilitate VOC-free, effective and energy-saving CO2 solvent systems for applications such as extraction, dyeing, dry cleaning, metal-plating, enhanced oil recovery and organic/inorganic or nanomaterial synthesis.
    Matched MeSH terms: Fluorocarbons/chemistry*
  12. Fulltext Characterization of the inheritance of field-evolved resistance to diamides in the fall armyworm (Spodoptera frugiperda) (Lepidoptera: Noctuidae) population from Puerto Rico
    Posos-Parra O, Mota-Sanchez D, Pittendrigh BR, Wise JC, DiFonzo CD, Patterson E
    PLoS One, 2024;19(2):e0295928.
    PMID: 38394153 DOI: 10.1371/journal.pone.0295928
    The fall armyworm (Spodoptera frugiperda) is one of the most destructive pests of corn. New infestations have been reported in the East Hemisphere, reaching India, China, Malaysia, and Australia, causing severe destruction to corn and other crops. In Puerto Rico, practical resistance to different mode of action compounds has been reported in cornfields. In this study, we characterized the inheritance of resistance to chlorantraniliprole and flubendiamide and identified the possible cross-resistance to cyantraniliprole and cyclaniliprole. The Puerto Rican (PR) strain showed high levels of resistance to flubendiamide (RR50 = 2,762-fold) and chlorantraniliprole (RR50 = 96-fold). The inheritance of resistance showed an autosomal inheritance for chlorantraniliprole and an X-linked inheritance for flubendiamide. The trend of the dominance of resistance demonstrated an incompletely recessive trait for H1 (♂ SUS × ♀ PR) × and an incompletely dominant trait for H2 (♀ SUS × ♂ PR) × for flubendiamide and chlorantraniliprole. The PR strain showed no significant presence of detoxification enzymes (using synergists: PBO, DEF, DEM, and VER) to chlorantraniliprole; however, for flubendiamide the SR = 2.7 (DEM), SR = 3.2 (DEF) and SR = 7.6 (VER) indicated the role of esterases, glutathione S- transferases and ABC transporters in the metabolism of flubendiamide. The PR strain showed high and low cross-resistance to cyantraniliprole (74-fold) and cyclaniliprole (11-fold), respectively. Incomplete recessiveness might lead to the survival of heterozygous individuals when the decay of diamide residue occurs in plant tissues. These results highlight the importance of adopting diverse pest management strategies, including insecticide rotating to manage FAW populations in Puerto Rico and other continents.
    Matched MeSH terms: Fluorocarbons*
  13. Levels, temporal trends, and tissue distribution of perfluorinated surfactants in freshwater fish from Asian countries
    Murakami M, Adachi N, Saha M, Morita C, Takada H
    Arch Environ Contam Toxicol, 2011 Nov;61(4):631-41.
    PMID: 21424221 DOI: 10.1007/s00244-011-9660-4
    Perfluorinated surfactants (PFSs) in Asian freshwater fish species were analyzed to investigate tissue distribution, temporal trends, extent of pollution, and level of PFS exposure through food intake. Freshwater fish species, namely carp, snakehead, and catfish, were collected in Japan, Vietnam, India, Malaysia, and Thailand, and 10 PFSs, including perfluorooctanesulfonate (PFOS) and perfluorooctanoate, were analyzed by liquid chromatography-tandem mass spectrometry. PFSs in carp in Tokyo were more concentrated in kidneys (Σ10 PFSs = 257 ± 95 ng/g wet weight [ww]) and livers (119 ± 36 ng/g ww) than in ovaries (43 ± 2 ng/g ww) and muscles (24 ± 17 ng/g ww). Concentrations of PFOS and its precursor, perfluorooctane sulfonamide, in livers of carp and in waters in Tokyo showed a dramatic decrease during the last decade, probably because of 3 M's phasing-out of the manufacture of perfluorooctanesulfonyl-fluoride-based products in 2000. In contrast, continuing contamination by long-chain perfluorocarboxylates (PFCAs) with ≥ 9 fluorinated carbons was seen in multiple media, suggesting that these compounds continue to be emitted. PFS concentrations in freshwater fish species in tropical Asian countries were generally lower than those in developed countries, such as Japan, e.g., for PFOS in muscle, Vietnam < 0.05-0.3 ng/g ww; India < 0.05-0.2 ng/g ww; Malaysia < 0.05-0.2 ng/g ww; Thailand < 0.05 ng/g ww; and Japan (Tokyo) = 5.1-22 ng/g ww. Daily intake of short-chain PFCAs with ≤ 8 fluorinated carbons from freshwater fish species in Japan was approximately one order of magnitude lower than that from drinking water, whereas daily intake of PFOS and long-chain PFCAs with ≥ 9 fluorinated carbons from freshwater fish species was comparable with or greater than that from drinking water. Because the risk posed by exposure to these compounds through intake of fish species is a matter of concern, we recommend the continued monitoring of PFS levels in Asian developing countries.
    Matched MeSH terms: Fluorocarbons/analysis; Fluorocarbons/pharmacokinetics*
  14. Fulltext A review on development of blood substitute
    Mislia Othman, Muhammad Azrul Zabidi
    Jurnal Sains Kesihatan Malaysia, 2020;18(2):59-71.
    MyJurnal
    This review paper aims to present an overview of the development of blood substitute particularly red blood cell substitute or artificial oxygen carrier. Knowledge on human blood inspired from the understanding of human blood circulation system. Ibn Nafis was first to describe that blood flow through respiratory system before entering the heart. This finding denied the claim that tiny pores present within the septum of the heart. Then, William Harvey further described human cardiovascular system in detail and contributed to better understanding on the roles of blood in body. Several blood transfusions were attempted using blood collected from human, animal and other blood substitutes such as milk before the practice was banned for almost 150 years in Europe. Major discoveries on blood group and antibody reaction have made blood transfusion safer. However, several issues and challenges have re-triggered the exploration to develop red cell substitutes. Two approaches have been taken to develop the red blood cell substitute which are classified into biological and chemical based oxygen carriers. The earliest efforts have been on haemoglobin based oxygen carrier (HBOC) and perfluorocarbon (PFC) while the recent developement are on polymer-based oxygen carrier and in-vitro stem cell derived red blood cell.
    Matched MeSH terms: Fluorocarbons
  15. Perfluorooctanesulfonate and related fluorochemicals in human blood from several countries
    Kannan K, Corsolini S, Falandysz J, Fillmann G, Kumar KS, Loganathan BG, et al.
    Environ Sci Technol, 2004 Sep 1;38(17):4489-95.
    PMID: 15461154
    Perfluorooctanesulfonyl fluoride based compounds have been used in a wide variety of consumer products, such as carpets, upholstery, and textiles. These compounds degrade to perfluorooctanesulfonate (PFOS), a persistent metabolite that accumulates in tissues of humans and wildlife. Previous studies have reported the occurrence of PFOS, perfluorohexanesulfonate (PFHxS), perfluorooctanoate (PFOA), and perfluorooctanesulfonamide (PFOSA) in human sera collected from the United States. In this study, concentrations of PFOS, PFHxS, PFOA, and PFOSA were measured in 473 human blood/serum/plasma samples collected from the United States, Colombia, Brazil, Belgium, Italy, Poland, India, Malaysia, and Korea. Among the four perfluorochemicals measured, PFOS was the predominant compound found in blood. Concentrations of PFOS were the highest in the samples collected from the United States and Poland (>30 ng/mL); moderate in Korea, Belgium, Malaysia, Brazil, Italy, and Colombia (3 to 29 ng/mL); and lowest in India (<3 ng/mL). PFOA was the next most abundant perfluorochemical in blood samples, although the frequency of occurrence of this compound was relatively low. No age- or gender-related differences in the concentrations of PFOS and PFOA were found in serum samples. The degree of association between the concentrations of four perfluorochemicals varied, depending on the origin of the samples. These results suggested the existence of sources with varying levels and compositions of perfluorochemicals, and differences in exposure patterns to these chemicals, in various countries. In addition to the four target fluorochemicals measured, qualitative analysis of selected blood samples showed the presence of other perfluorochemicals such as perfluorodecanesulfonate (PFDS), perfluoroheptanoic acid (PFHpA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorododecanoic acid (PFDoA), and perfluoroundecanoic acid (PFUnDA) in serum samples, at concentrations approximately 5- to 10-fold lower than the concentration of PFOS. Further studies should focus on identifying sources and pathways of human exposure to perfluorochemicals.
    Matched MeSH terms: Fluorocarbons/blood*
  16. Nasal or Temporal Internal Limiting Membrane Flap Assisted by Sub-Perfluorocarbon Viscoelastic Injection for Macular Hole Repair
    Chou HD, Chong YJ, Teh WM, Chen KJ, Liu L, Chen YP, et al.
    Am J Ophthalmol, 2021 03;223:296-305.
    PMID: 32950511 DOI: 10.1016/j.ajo.2020.09.023
    PURPOSE: To compare the outcomes between using a nasal and a temporal inverted internal limiting membrane (ILM) flap both assisted by a novel technique in repairing a full-thickness macular hole (FTMH).

    DESIGN: Retrospective interventional case series.

    METHODS: Thirty-nine eyes from 39 patients with a FTMH <600 μm were included from a single institution. All patients underwent vitrectomy using a semicircular single-layered ILM inverted flap assisted by a sub-perfluorocarbon liquid injection of ophthalmic viscoelastic device (OVD) technique. Best-corrected visual acuity (BCVA) and spectral domain optical coherence tomography were used to compare outcomes between nasal (n = 19) and temporal (n = 20) groups.

    RESULTS: At 6 months postoperatively, all FTMHs closed and BCVA were significantly improved. Overall, 36 eyes (92%) achieved U-shaped closure, and ellipsoid zone restoration was noted in 24 eyes (62%). An ILM flap was present in 29 eyes (74%) and 86% remained single-layered. There were significantly more deep inner retinal dimples in the temporal group (35%) compared with 5% in the nasal group (P = .04), but these were unrelated to BCVA. Significant retinal thinning in the temporal outer sub-field was noted in the temporal group and was negatively correlated with BCVA (rho [ρ]: - .53; P = .03). No significant postoperative retinal displacement was noted in either group.

    CONCLUSIONS: The technique of using sub-perfluorocarbon liquid injection of OVD secured single-layered flaps intraoperatively and postoperatively. Both the nasal and temporal inverted ILM flaps repaired FTMH and improved visual acuity. However, both temporal macular thinning and deep inner retinal dimples were significantly greater in the temporal group.

    Matched MeSH terms: Fluorocarbons/administration & dosage*
  17. Fulltext Liquid Chromatographic Tandem Mass Spectrometric (LC-MS/MS) Determination of Perfluorooctane Sulfonate (PFOS) and Perfluorooctanoic Acid (PFOA) in the Yolk of Poultry Eggs in Malaysia
    Tahziz A, Mohamad Haron DE, Aziz MY
    Molecules, 2020 May 16;25(10).
    PMID: 32429475 DOI: 10.3390/molecules25102335
    Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are widely used in products, and are known for their water and grease repellent properties. The persistence nature and potential toxicity of these substances have raised substantial concerns about health effects. Regarding humans, food consumption has reportedly been a significant source of exposure for both compounds. Hence, this study was performed to develop and validate an analytical method for PFOS and PFOA in egg yolks using liquid chromatographic tandem mass spectrometry (LC-MS/MS) followed by the determination of concentration of both compounds in the yolk of poultry eggs in Malaysia. A total of 47 poultry egg yolk samples were extracted by a simple protein precipitation technique using acetonitrile. The analytical method was developed using LC-MS/MS and validated based on the Food and Drug Administration (FDA)'s Bioanalytical Method Validation guidelines. The results revealed that PFOS was quantitatively detected in six samples, with the concentration range between 0.5 and 1.01 ng g-1. Among these, five samples were from home-produced chicken eggs, and one sample was from a quail egg. The levels of PFOA in all samples were below the quantifiable limit (<0.1 ng g-1). This indicated that the contamination of PFCs in poultry eggs were mostly attributed to the nature of free foraging animals, which had direct contact with the contaminants in soil and feed. In conclusion, a fast and robust analytical method for analyzing PFOS and PFOA in egg yolk samples using LC-MS/MS was successfully developed and validated. The presence of these emerging contaminants in this study signified widespread pollution in the environment.
    Matched MeSH terms: Fluorocarbons/analysis*
  18. Fulltext Pneumatic retinopexy for treatment of posterior pole detachment following vitreoretinal surgery for diabetic tractional retinal detachment threatening the fovea
    Bastion ML
    BMJ Case Rep, 2012;2012.
    PMID: 22878988 DOI: 10.1136/bcr-2012-006303
    To describe the usage of 100% perfluoropropane and subsequent laser retinopexy for the repair of posterior pole retinal detachment in a previously vitrectomised patient with diabetic tractional detachment.
    Matched MeSH terms: Fluorocarbons
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