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Glove Selection for Work with Acrylates Including Those Cured by Ultraviolet, Visible Light, or Electron Beam
Published in Robert N. Phalen, Howard I. Maibach, Protective Gloves for Occupational Use, 2023
The most important exception used in industrial volume is epoxy acrylates. This name, widely used in the industry, might be misleading to medical professionals. Epoxy acrylates are oligomers that are produced via the reaction of an epoxy resin with acrylic acid. In this reaction, the epoxy groups are converted into an α-hydroxy ester, and virtually zero residual epoxy groups can be detected in the final product.
Ultrastructural Immunocytochemistry
Published in Joan Gil, Models of Lung Disease, 2020
Samuel S. Spicer, Bradley A. Schulte
The physicochemical nature of epoxy resins poses obstacles to immunostaining. First, the epoxy medium resists penetration by most staining reagents, particularly those of high molecular weight, because a medium sufficiently inelastic to yield ultrathin sections lacks the porosity needed to allow diffusion of reagents into it. Hydrophobicity of the medium presumably also plays a part in the impenetrability to reagents in aqueous solution. In addition, chemical reagents in the medium, including the oxidants effecting polymerization, adversely affect the antigenicity of cell constituents. The prolonged high temperature required for polymerization of the resin also contributes to denaturation of the antigen.
The toxic environment
Published in Anna Bellisari, The Anthropology Of Obesity in the United States, 2016
Natural estrogenic compounds such as genistein found in soy-based products and some pharmaceutical items function as obesogens (Newbold et al. 2009). Bisphenol A (BPA) also has estrogenic properties and is an ingredient of polycarbonate plastics and epoxy resins in many consumer products (Vandenberg 2011). It is found in baby bottles, reusable water bottles, sports equipment, eyeglasses, CDs, medical devices, coatings of food and beverage cans, water pipes, dental sealants, paints, papers, cardboards, cigarette filters, and American banknotes, as well as in the environment in air, dust, sewage, and water and leaches out of products under normal use. Levels of BPA known to permanently harm animals have been found in urine samples of people from Asia, the European Union, Canada, and the US (Vandenberg 2011), with children and adolescents manifesting the highest levels. BPA and many other endocrine disrupters were found in sewage effluents in Australia, Canada, Germany, Italy, Spain, Korea, Japan, China, the UK, and the US (Sun et al. 2014). Even though Canadian and U.S. citizens did not differ in BPA exposure until 1994, the U.S. population now has concentrations that are twice as high as Canadians, perhaps due to differences in packaging practices, production levels, or other (unknown) factors. Even low exposure to BPA can affect development of reproductive organs, timing of puberty, and regulation of body mass and metabolism (Le Corre et al. 2015). BPA also activates PPAR gamma that induces adipogenesis (Janesick and Blumberg 2011; Pereira-Fernandes et al. 2013a).
Microchannel-embedded implantable device with fibrosis suppression for prolonged controlled drug delivery
Published in Drug Delivery, 2022
Han Bi Ji, Jae Young Hong, Cho Rim Kim, Chang Hee Min, Jae Hoon Han, Min Ji Kim, Se-Na Kim, Cheol Lee, Young Bin Choy
The PMMA plates (thickness = 2 mm) and PEG (average MW = 6 kDa) were purchased from ENGP (Incheon, Republic of Korea) and Acros Organics (Geel, Belgium), respectively. The DF (99.9% purity), TR (98% purity), phosphoric acid, acetonitrile, Tween® 80, ammonium bicarbonate, and formalin (neutral buffered, 10%) were obtained from Sigma (St. Louis, MO). Intravenous catheters and ethylenediaminetetraacetic acid (EDTA) tubes were purchased from BD Biosciences (Franklin Lakes, NJ). Ethanol and ammonium acetate were purchased from Daejung Chemicals (Siheung, Republic of Korea). Betadine was obtained from Green Pharmaceutical (Seoul, Republic of Korea). Phosphate-buffered saline (PBS; pH 7.4) and Ideal 9144 masking tapes were obtained from the Seoul National University Hospital Biomedical Research Institute (Seoul, Republic of Korea) and American Biltrite (Lowell, MA), respectively. Medical epoxy (EPO-TEK® 301-2) was obtained from Epoxy Technology (Billerica, MA).
Antimicrobial effectiveness of root canal sealers against Enterococcus faecalis
Published in Biomaterial Investigations in Dentistry, 2022
Paola Castillo-Villagomez, Elizabeth Madla-Cruz, Fanny Lopez-Martinez, Idalia Rodriguez-Delgado, Jorge Jaime Flores-Treviño, Guadalupe Ismael Malagon-Santiago, Myriam Angelica de La Garza-Ramos
Complete removal of microorganisms from the root canal system in all patients is impossible; therefore, filling materials with antimicrobial activity for the root canal are used to reduce microorganisms and prevent infections. On the other hand, many endodontic failures occur after removing necrotic or inflammatory tissue with microorganisms. These tissues need to be retreated and managed with apical surgery; however, filtration failure occurs in 15% to 22% [4]. These complications are attributed to the lack of root canal sealing after endodontic treatment due to the high hydrophobicity and water absorption caused by the solubility of the cement. The development of new ceramic-type materials has improved sealing to reduce this problem. Epoxy resin is widely used as a gold standard, although it still has limitations, such as mutagenicity, cytotoxicity, inflammation, and hydrophobicity. Calcium silicate-based sealers with high biocompatibility and hydrophilicity have also been introduced. Both cements reduce microfiltration thanks to properties in their dynamic environment and being biocompatible in this application [5].
Transmission electron microscopic analysis of glyphosate induced cytotoxicity and its attenuation by N-acetyl-L-cysteine in caprine testicular germ cells in vitro
Published in Ultrastructural Pathology, 2021
Jitender Kumar Bhardwaj, Vijay Kumar, Harish Panchal, Som Nath Sachdeva
After GLY treatment along with NAC supplementation, the testicular tissues were fixed in 2.5% glutaraldehyde in 0.2 M phosphate buffer saline (PBS) (pH 7.2–7.4) at 4°C for 24 h. After fixation, tissues were finally trimmed to appropriate sizes (˜1 mm3), post-fixed in 1.3% osmium tetraoxide at 4°C for 2 h followed by dehydration in graded acetone series. Tissues were cleared in epoxy propane and its embedding was done in epoxy-resin blocks. For selection of the required area, initially tissues were sectioned at 1 µm thickness and observed under phase-contrast microscope. After selection of the required area, tissue sections of 60–90 nm thickness were obtained using glass knives and mounted on mesh grids. The sections were stained with uranyl acetate and lead citrate followed by their examination (two samples in each group) under Morgagni 268 D TEM from FEI, Netherlands, installed at the All India Institute of Medical Sciences (AIIMS), New Delhi.8,31