Environmental contamination and human exposure to PFASs near a fluorochemical production plant: Review of historic and current PFOA and GenX contamination in the Netherlands

Fluorochemical production plants (FPP) are primary emission sources of per- and polyfluoroalkyl substances (PFASs) to the local environment. An FPP located in the Netherlands has historically used perfluorooctanoic acid (PFOA) for fluoropolymer production and is currently using GenX (HFPO-DA; 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propionic acid) as a replacement. This study reviewed existing data from open access reports and peer reviewed publications on the environmental presence of PFOA and GenX in environmental matrices such as surface water, groundwater, soil and vegetation. Published data on human exposure to PFOA and GenX (i.e. via drinking water and food as well as blood monitoring) were reviewed in order to assess the influence of the FPP on contamination of the local population. Concentrations in environmental and human exposure samples were compared to (inter)national quality standards or risk limits. The data showed higher PFOA and GenX concentrations in surface water, groundwater, soil and vegetation samples taken close to point sources, and the highest observed concentrations exceeded these standards and limits (except for PFOA in soil). Drinking water and food also contained higher PFOA and GenX concentrations in samples taken close to point sources compared to samples further away. Tolerable daily intake (TDIs) for both PFASs were exceeded, however, only in a maximum exposure scenario. Blood monitoring of the local population near the FPP, and FPP workers, confirmed high exposure can occur as blood concentrations of several individuals exceeded the safe level. This paper provides a comprehensive overview on PFOA and GenX contamination close to point sources in the Netherlands.</p

Інформаційні ресурси: нові підходи до визначення поняття

У статті окреслено нові підходи щодо визначення категорій «інформаційний ресурс», «інформаційний потенціал», їх класифікації та функцій. Зазначається, що інформаційні ресурси нині стають системотворчим фактором життєдіяльності суспільства.In the article, the author determines new approaches in defining the categories of «information resource», «information potential», their classification and functions. The information resources are considered to become the important system-forming factor of the activity of society

Новий формат співробітництва (Договір про співробітництво між Національною академією наук України і Національною академією наук Киргизької Республіки)

A one-pot method has been developed for the oxidative cleavage of internal alkenes into aldehydes by using 0.5 mol % of the nonheme iron complex [Fe(OTf)2(mix-bpbp)] (bpbp=N,N′-bis(2-picolyl)-2,2′-bipyrrolidine) as catalyst and 1.5 equivalents of hydrogen peroxide and 1 equivalent of sodium periodate as oxidants. A mixture of diastereomers of the chiral bpbp ligand can be used, thereby omitting the need for resolution of its optically active components. The cleavage reaction can be performed in one pot within 20 h and under ambient conditions. Addition of water after the epoxidation, acidification and subsequent pH neutralization are crucial to perform the epoxidation, hydrolysis, and subsequent diol cleavage in one pot. High aldehyde yields can be obtained for the cleavage of internal aliphatic double bonds with cis and trans configuration (86–98 %) and unsaturated fatty acids and esters (69–96 %). Good aldehyde yields are obtained in reactions of trisubstituted and terminal alkenes (62–63 %). The products can be easily isolated by a simple extraction step with an organic solvent. The presented protocol involves a lower catalyst loading than conventional methods based on Ru or Os. Also, hydrogen peroxide can be used as the oxidant in this case, which is often disproportionated by second- and third-row metals. By using only mild oxidants, overoxidation of the aldehyde to the carboxylic acid is prevented

Проблеми ісламу України в їх науковому відтворенні

The Pd/TOMPP-catalysed (TOMPP = tris(2-methoxyphenyl)phosphine) telomerisation of 1,3-butadiene was studied under solvent- and base-free conditions with phenolic substrates that can be potentially derived from lignin. Large differences in catalytic activity were observed, with reactivity increasing in the order of phenol, p-cresol, guaiacol, creosol and syringol. This reactivity trend can be attributed to the substrates’ relative nucleophilicities, as induced by the donating effects of the p-methyl and o-methoxy substituents. The chosen reaction conditions, i.e. temperature, ligand/metal and butadiene/substrate ratios, strongly influenced both the conversion and selectivity of the reaction. Remarkably, the composition of the reaction medium, i.e. the butadiene/substrate ratio, exerted a strong influence on the linear/branched ratio. High conversions and selectivities to the linear products are obtained when excess butadiene is used. The linear telomer products could be readily converted from O-alkylated to Calkylated phenolics via the thermal Claisen rearrangement. High conversions and selectivities were observed after 2 hours at 200 1C. Branched o-octadienyl phenols were obtained in all cases except for the syringol telomer which gave the linear p-octadienyl product exclusively

Функциональная нагрузка обобщающе-выделительных местоимений в предложении

A range of silanes was synthesized by the reaction of HSiCl3 with iminopyrrole derivatives in the presence of NEt3. In certain cases, intramolecular hydrosilylation converts the imine ligand into an amino substituent. This reaction is inhibited by factors such as electron-donating substitution on Si and steric bulk. The monosubstituted (DippIMP)SiHMeCl (DippIMP=2-[N-(2,6-diisopropylphenyl)iminomethyl]pyrrolide), is stable towards hydrosilylation, but slow hydrosilylation is observed for (DippIMP)SiHCl2. Reaction of two equivalents of DippIMPH with HSiCl3 results in the hydrosilylation product (DippAMP)(DippIMP)SiCl (DippAMP=2-[N-(2,6-diisopropylphenyl)aminomethylene]pyrrolide), but the trisubsitituted (DippIMP)3SiH is stable. Monitoring the hydrosilylation reaction of (DippIMP)SiHCl2 reveals a reactive pathway involving ligand redistribution reactions to form the disubstituted (DippAMP)(DippIMP)SiCl as an intermediate. The reaction is strongly accelerated in the presence of chloride anions

Induction of specific protein tyrosine phosphatase transcripts during differentiation of mouse embryonal carcinoma (F9) cells

AbstractWe have investigated the pattern of PTPase transcript expression during in vitro differentiation of mouse embryonal carcinoma (F9) cells. While the transcripts of most PTPases were unchanged or undetected during embryonal differentiation induced by retinoic acid, several PTPase transcripts exhibited distinct patterns of induction. Mutant cells defective in differentiation did not display the induction of some of these PTPase transcripts. Interestingly, three out of the four PTPase transcripts induced were the same PTPase transcripts induced during in vitro erythroid differentiation of mouse erythroleukemia (MEL) cells [(1982) Biochem. Biophys. Res. Commun. 107, 1104–1109]. The possible role played by specific PTPases in cell differentiation is discussed

Розробка мобільної технології ремонту низьковуглецевих стальних труб низького та високого тиску методом пайки низькотемпературними припоями

Розроблено технологію безвогневого ремонту дефектів конструкцій з низьковуглецевих сталей шляхом пайки низькотемпературними припоями. Розроблено та заявлено новий склад легкоплавкого припою на базі олова з домішками міді та вісмуту. Припій оптимально поєднує властивості рідкоплинності, корозійної стійкості, міцності та адгезійної міцності. Технологію пайки сталей низькотемпературними припоями із застосуванням високочастотного генератора електричного струму доведено до стану практичного застосування.Разработана технология безогневого ремонта дефектов конструкций из низкоуглеродистых сталей путем пайки низкотемпературными припоями. Разработан и заявлен новый состав легкоплавкого припоя на базе олова, с добавками меди и висмута. Припой оптимально объединяет свойства жидкотекучести, коррозионной стой кости, прочности и адгезионной прочности. Технологию пайки сталей низкотемпературными припоями с применением высокочастотного генератора электрического тока доведено до состояния практического применения.The technology of out fire defects repair in low carbon steel constructions by soldering with low- temperature solders is developed. The new fusible tin rich solder composition containing copper and bismuth additives is developed and declared. The solder has optimum properties of liquid stream, corrosion resistance, durability and adhesion strength. The low carbon steel soldering technology with application of high-frequency electric current generator is carried to practical application

Organohalogen contaminants and metabolites in cerebrospinal fluid and cerebellum gray matter in short-beaked common dolphins and Atlantic white-sided dolphins from the western North Atlantic

Author Posting. © The Authors, 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Environmental Pollution 157 (2009):2345-2358, doi:10.1016/j.envpol.2009.03.024.Concentrations of several congeners and classes of organohalogen contaminants (OHCs) and/or their metabolites, namely organochlorine pesticides (OCs), polychlorinated biphenyls (PCBs), hydroxylated-PCBs (OH-PCBs), methylsulfonyl-PCBs (MeSO2-PCBs), polybrominated diphenyl ether (PBDE) flame retardants, and OH-PBDEs, were measured in cerebrospinal fluid (CSF) of short-beaked common dolphins (n = 2), Atlantic white-sided dolphins (n = 8), and gray seal (n = 1) from the western North Atlantic. In three Atlantic white-sided dolphins, cerebellum gray matter (GM) was also analyzed. The levels of OCs, PCBs, MeSO2-PCBs, PBDEs, and OH-PBDEs in cerebellum GM were higher than the concentrations in CSF. 4-OH-2,3,3’,4’,5-pentachlorobiphenyl (4-OH-CB107) was the only detectable OH-PCB congener present in CSF. The sum (Σ) OH-PCBs/ Σ PCB concentration ratio in CSF was approximately two to three orders of magnitude greater than the ratio in cerebellum GM for dolphins.This study was supported through an Environmental Protection Agency STAR fellowship (U-91616101-2) and a National Woman’s Farm and Garden Association Scholarship awarded to Dr. Eric Montie, and by the WHOI Ocean Life Institute, the Quebec Labrador Fund/Atlantic Center for the Environment, the WHOI Academic Programs Office, the Sawyer Endowment, Walter A. and Hope Noyes Smith, and Dr. David Mann at the University of South Florida

Rhenium-Catalyzed Dehydration and Deoxydehydration of Alcohols and Polyols: Opportunities for the Formation of Olefins from Biomass

In view of the depletion of petroleum oils, new synthetic routes for the sustainable production of chemicals, fuels, and energy from renewable biomass sources are currently widely investigated. In particular, nonedible sugars and polyols are promising starting materials to produce olefins by dehydration, deoxygenation, or deoxydehydration (DODH) of these poly vicinal alcohols. In this perspective, we highlight the recent evolution of rhenium-catalyzed dehydration and DODH of biomass-derived alcohols and polyols to obtain olefins. Improving over the classical acid-catalyzed dehydration reaction, rhenium-mediated systems are very selective and more active to provide high yields of olefin products, but dehydration alone cannot be used to fully defunctionalize sugars. This issue is addressed by a growing research effort in the field of Re-catalyzed DODH, which allows complete dehydroxylation to form olefins in high yield. Recent developments in this field include the development of new molecular rhenium catalysts, the application of cheaper and more available reductants, and a growing mechanistic understanding owing to both experimental and computational studies. Finally, recent efforts to move beyond rhenium toward cheaper metals (Mo, V) are discussed