Search results for "Phthalic acid"
showing 10 items of 41 documents
Picotamide, a combined inhibitor of thromboxane A2 synthase and receptor, reduces 2-year mortality in diabetics with peripheral arterial disease: the…
2004
Aims Patients with diabetes are at excessive risk of mortality and cardiovascular morbidity. Previous studies suggest that aspirin may be less effective in diabetic patients. In this multi-centre, randomized, double blind trial picotamide, a dual inhibitor of thromboxane A2 synthase and receptor, was compared with aspirin for the prevention of mortality and major cardiovascular events in diabetics with peripheral arterial disease (PAD). Methods and results A total of 1209 adults aged 40–75 years with type 2 diabetes and PAD were randomized to receive picotamide (600 mg bid) or aspirin (320 mg od) for 24 months. The cumulative incidence of the 2 years overall mortality was significantly lowe…
Metalation and N-alkylation of some polyamides
1981
Totally N-substituted polyamides were synthesized starting from poly(2,4,4-trimethylhexamethylene terephthalamide) by metalation of the amide groups and subsequent reaction with several electrophiles. Polyamides of this structure are not available from terephthalic acid and the corresponding diamines by polycondensation. This N-alkylation reaction can be used for the synthesis of comb-like graft copolymers. The solubilitity and the thermal properties of these polyamide derivatives are described.
Oligo(phenylenevinylene)s with increased electron affinity: 1,3,4-oxadiazoles in the main chain
2001
Stilbenoid chromophores and 2,5-diaryl-1,3,4-oxadiazoles are compounds with wide technical importance. Their intense fluorescence is used in szintillators and optical whiteners and their semiconducting properties makes them valuable emissive or electron conducting layers in organic light emitting diodes (OLED). The synthesis and the electronic spectra of soluble oligo(phenylenevinylene)s with 1,3,4-oxadiazoles in the main chain are presented. The Huisgen reaction of tetrazole-terminated stilbenoid compounds with aromatic acyl chlorides yields model compounds, isophthalic acid dichlorides lead to soluble polymers with well-defined conjugated segments, as can be seen in the electronic spectra…
Evaluation of anti-androgenic activity of di-(2-ethylhexyl)phthalate
2005
International audience; DEHP is a widely used platiciser in the manufacture of PVC-based materials. It is known to disrupt the reproductive tract development in male rats. We have performed the Hershberger assay with DEHP on an immature castrated rat model to check if DEHP antagonise the testosterone propionate androgenic effect on the accessory sex organs development. DEHP significantly decreased the BC/LA muscles, the prostate, and the seminal vesicles relative weights from 100, 200, and 400 mg/kg bw/day, respectively. DEHP increased the liver relative weight from 100 mg/kg bw/day. A study was also performed on MDA-MB453 cell line stably transfected with pMMTVneo-Luc with DEHP and its maj…
Environmental Aspect Concerning Phthalates Contamination: Analytical Approaches and Assessment of Biomonitoring in the Aquatic Environment
2023
This review is a survey of recent progress in studies concerning the impact of phthalic acid esters in aquatic organisms. After introducing the classification, properties, sources, fate, and toxic effects related to phthalates, an overview of the techniques of extraction and analysis of these substances is provided. As a result, the general concepts of environmental bioindicators, biomonitoring systems, and other concepts related to phthalate contamination in the aquatic environment are presented. Recent bioaccumulation data of different phthalates are summarised in a table and organised according to the type of organism, tissue, and geographical area of sampling. Bioindicator organisms tha…
Shear and nonisothermal elongational characterization of a liquid crystalline polymer
1989
A commercial liquid crystalline polymer (LCP) sample was characterized both in shear and in nonisothermal elongational flow over a wide range of temperatures (240–350°C). The LCP sample employed was a copolyesteramide of 2,6 hydroxynaphthoic acid, terephthalic acid, and aminophenol manufactured by Celanese and commercially known as Vectra B950. The viscosity decreases dramatically at temperatures above the crystal-nematic transition of the polymer. At lower temperatures, the extrusion of the sample is mainly due to plastic flow. Die-swell values are very small and contraction of the extrudate is also revealed, but the sample shows high elasticity. The polymer is not spinnable at very low te…
The BIOSAFEPAPER project for in vitro toxicity assessments: preparation, detailed chemical characterisation and testing of extracts from paper and bo…
2008
International audience; Nineteen food contact papers and boards and one non-food contact board were extracted following test protocols developed within European Union funded project BIOSAFEPAPER. The extraction media were either hot or cold water, 95% ethanol or Tenax, according to the end use of the sample. The extractable dry matter content of the samples varied from 1200 to 11,800 mg/kg (0.8-35.5 mg/dm2). According to GC-MS the main substances extracted into water were pulp-derived natural products such as fatty acids, resin acids, natural wood sterols and alkanols. Substances extracted into ethanol particularly, were diisopropylnaphthalenes, alkanes and phthalic acid esters. The non-foo…
Determination of organic and inorganic anions in insect haemolymph and midgut contents by ion chromatography
1997
A simple and rapid ion-exchange chromatographic method with conductimetric detection for the determination of carboxylic acids (succinic, malic and citric) and inorganic anions (chloride, phosphate and sulphate) in haemolymph and midgut content of Lepidoptera larvae is provided. The mobile phase is 0.975 mM phthalic acid at pH 4.1. The procedure of sample extractions was simple. Comparison of the results with whose reported in the bibliography showed that the values were similar. The ion-exchange chromatographic–conductimetric detection method permits the analysis of various organic and inorganic anions in small biological samples.
Risk assessment of exposure to phthalates in breastfeeding women using human biomonitoring
2020
In this study, we assessed the presence of 14 phthalate metabolites in the urine of 104 lactating mothers from Valencia (Spain) who took part in the human biomonitoring project BETTERMILK. Nine of the metabolites studied showed detection frequencies >80%, whereas the rest of the metabolites presented low detection frequencies (<5%). The concentrations ranged from <LoQ to 1291 ng/mL with monoethyl phthalate showing the highest concentration, with a geometric mean of 34.90 ng/mL. In general, the phthalate metabolite levels quantified in the present study were lower than the urinary levels found in previous studies that involved lactating mothers. The consumption of packaged juices and the fre…
Effect of modulator connectivity on promoting defectivity in titanium–organic frameworks
2020
The recognition of defect chemistry as a true synthetic tool for targeted creation of defects and controllable performance remains limited by the pool of frameworks explored. The value of defect engineering in controlling the properties of defective frameworks has been beautifully exemplified and largely demonstrated with UiO-type materials based on Zr(iv) nodes. However, titanium–organic frameworks remain largely unexplored in this context arguably due to the complex chemistry in solution of Ti(iv) and the difficulties in growing crystalline solids. We report a systematic study on the ability of mono- and dicarboxylic modulators (benzoic and isophthalic acid) to promote defect creation in …