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Data in Brief Apr 2022A material flow analysis of the main plastic types used and arising as waste in Switzerland in 2017 is conducted, including consideration of stock change. Seven main...
A material flow analysis of the main plastic types used and arising as waste in Switzerland in 2017 is conducted, including consideration of stock change. Seven main plastic application segments are distinguished (packaging; building and construction; automotive; electrical and electronic equipment; agriculture; household items, furniture, leisure and others; and textiles), further divided into 54 product subsegments. For each segment, the most commonly used plastic types are considered, in total including eleven plastic types (HDPE, LDPE, PP, PET, PS, PVC, ABS, HIPS, PA, PC, and PUR). All product life cycle stages are regarded, including the determination of the product subsegments in which the individual post-consumer secondary materials obtained from mechanical recycling are applied. The underlying data are gathered from official statistics and administrative databases, scientific literature, reports by industry organizations and research institutions, websites, and personal communication with stakeholders. The compiled data are then reconciled. All flow data are provided and depicted in two Sankey diagrams: one diagram shows the material flows on a product-subsegment level and the second one on a plastic-type level. Users may retrieve the data with a script and transfer them into a relational database. The present material flow analysis data are used as a basis for the scenario analysis in Klotz et al. [1]. Besides scenario modelling, the data can be used in conducting life cycle assessments. Both utilizations can serve as a support for designing future plastic flow systems.
PubMed: 35282173
DOI: 10.1016/j.dib.2022.108001 -
Materials (Basel, Switzerland) Dec 2022Fracture toughness is one of the main factors influencing the durability of light-cured composites used for dental restorations and fillings. One of the methods of...
Fracture toughness is one of the main factors influencing the durability of light-cured composites used for dental restorations and fillings. One of the methods of increasing the fracture toughness is the modification of the matrix with liquid acrylonitrile-free liquid rubber. This study aimed to assess the miscibility of acrylonitrile-free liquid rubber with a blend of resins and their stability over time, and to determine the optimal amount of liquid rubber (LR) in the blend due to mechanical properties. Two blends of dimethacrylate resins were used: resin "F" composed of BisGMA (60 wt.%), TEGDMA (20 wt.%), BisEMA (10 wt.%) and UDMA (10 wt.%), and "C" resin containing BisGMA (40 wt.%), TEGDMA (40 wt.%), BisEMA (10 wt.%) and UDMA (10 wt.%). The modifier Hypro 2000X168LC VTB liquid rubber was used in at 1%, 2%, 3%, 4%, 5%, 10%, 15% and 20% by weight in the resin blend. The miscibility was assessed by microscopy. The fracture toughness, flexural strength and Young's modulus were determined in the bending test. The results showed that the solubility of the liquid rubber depends on the ratio of BisGMA/TEGDMA in the resins. In resins with 40 wt.% TEGDMA, the LR solubility was as high as 5%, while resins with 20 wt.% TEGDMA, the liquid rubber did not dissolve. The LR-resin mixtures showed good time stability, and no changes in the size or morphology of the rubber domains were found after 24 h of mixing. The maximum fracture toughness (2.46 MPa m) was obtained for 5 wt.% LR in resin F and for 15 wt.% LR in resin C (2.53 MPa m). The modification with liquid rubber resulted in an exponential reduction in both flexural strength and Young's modulus. The analysis of the results of the mechanical tests allowed us to determine the optimal amount of LR for both resins. For resin F it was 5.4 wt.%, and for resin C it was 8.3 wt.%. It can be stated that the optimal amount of liquid rubber increases with its solubility in the resin.
PubMed: 36614425
DOI: 10.3390/ma16010087 -
Molecules (Basel, Switzerland) Mar 2021An atom economical method for the preparation of variously substituted 4-pyrrolo[2,3-]oxazoles was developed on the basis of thermal isomerization of...
An atom economical method for the preparation of variously substituted 4-pyrrolo[2,3-]oxazoles was developed on the basis of thermal isomerization of 5-(2-azirin-2-yl)oxazoles. The latter were prepared by Rh(oct) catalyzed reaction of 2-(3-aryl/heteroaryl)-2-diazoacetyl-2-azirines with a set of substituted acetonitriles, benzonitriles, acrylonitrile and fumaronitrile. According to DFT calculations the transformation of 5-(2-azirin-2-yl)oxazole to 4-pyrrolo[2,3-]oxazole occurs through the nitrenoid-like transition state to give a 3a-pyrrolo[2,3-]oxazole intermediate, followed by 1,5-H-shift.
PubMed: 33810476
DOI: 10.3390/molecules26071881 -
EClinicalMedicine Jan 2021Marijuana smoke contains some of the same toxicants present in tobacco smoke. Marijuana smoking is prevalent among HIV+ individuals, but few studies have characterized...
Acrolein and other toxicant exposures in relation to cardiovascular disease among marijuana and tobacco smokers in a longitudinal cohort of HIV-positive and negative adults.
BACKGROUND
Marijuana smoke contains some of the same toxicants present in tobacco smoke. Marijuana smoking is prevalent among HIV+ individuals, but few studies have characterized smoke-related toxicants or associated health outcomes in exclusive marijuana users.
METHODS
This longitudinal study included 245 participants over age 40 (76% HIV+). 33 plasma and 28 urine metabolites of nicotine, ∆-9-trans-tetrahydrocannabinol, polycyclic aromatic hydrocarbons, and volatile organic compounds were assayed by liquid or gas chromatography/mass spectrometry. Exposures and health outcomes were assessed from surveys and medical records.
FINDINGS
At baseline, 18% of participants were marijuana-only smokers, 20% tobacco-only smokers, and 24% dual marijuana-tobacco smokers (median (IQR) age 53 (47-60) years, 78% male, 54% white race). Marijuana smoking was independently associated with elevated plasma naphthalenes, 2-hydroxyfluorene sulfate, 4-vinylphenol sulfate, and o-cresol sulfate 0·05) and urine acrylonitrile and acrylamide metabolites (0·05), but levels were lower than those associated with tobacco smoking. Acrolein metabolite N-Acetyl-S-(3-hydroxypropyl)-l-cysteine (3HPMA) was significantly elevated in plasma and urine in tobacco-only and dual but not marijuana-only smokers, and correlated with nicotine metabolites (0·05). The highest tertile of 3HPMA was associated with increased cardiovascular disease diagnoses independent of tobacco smoking, traditional risk factors, and HIV status (odds ratio [95% CI] 3·34 [1·31-8·57]; 0·012).
INTERPRETATION
Smoke-related toxicants, including acrylonitrile and acrylamide metabolites, are detectable in exclusive marijuana smokers, but exposures are lower compared with tobacco or dual smokers. Acrolein exposure is increased by tobacco smoking but not exclusive marijuana smoking in HIV+ and HIV- adults, and contributes to cardiovascular disease in tobacco smokers.
FUNDING
U.S. NIH.
PubMed: 33554087
DOI: 10.1016/j.eclinm.2020.100697 -
Analytical Chemistry Oct 2022This manuscript details the first report of a complete additively manufactured rotating disk electrode setup, highlighting how high-performing equipment can be designed...
This manuscript details the first report of a complete additively manufactured rotating disk electrode setup, highlighting how high-performing equipment can be designed and produced rapidly using additive manufacturing without compromising on performance. The additively manufactured rotating disk electrode system was printed using a predominantly acrylonitrile butadiene styrene (ABS) based filament and used widely available, low-cost electronics, and simplified machined parts to create. The additively manufactured rotating disk electrode system costs less than 2% of a comparable commercial solution (£84.47 ($102.26) total). The rotating disk electrode is also additively manufactured using a carbon black/polylactic acid (CB/PLA) equivalent, developing a completely additively manufactured rotating disk electrode system. The electrochemical characterization of the additively manufactured rotating disk electrode setup was performed using hexaamineruthenium(III) chloride and compared favorably with a commercial glassy carbon electrode. Finally, this work shows how the additively manufactured rotating disk electrode experimental system and additive manufactured electrodes can be utilized for the electroanalytical determination of levodopa, a drug used in the treatment of Parkinson's disease, producing a limit of detection of 0.23 ± 0.03 μM. This work represents a step-change in how additive manufacturing can be used in research, allowing the production of high-end equipment for hugely reduced costs, without compromising on performance. Utilizing additive manufacturing in this way could greatly enhance the research possibilities for less well-funded research groups.
Topics: Acrylonitrile; Butadienes; Carbon; Chlorides; Electrodes; Levodopa; Polyesters; Soot; Styrenes
PubMed: 36129134
DOI: 10.1021/acs.analchem.2c02884 -
Membranes Jul 2023Cellulose and copolymers of acrylonitrile (PAN) are characterized by their chemical resistance to several conventional solvents. Therefore, these polymers are often used...
Cellulose and copolymers of acrylonitrile (PAN) are characterized by their chemical resistance to several conventional solvents. Therefore, these polymers are often used to obtain membranes for the recovery of such solvents. In this work, for the first time, composite membranes formed from highly concentrated mixed solutions based on cellulose and PAN are considered (the total content of polymers is 18 wt.%). For mixed solutions, the morphology and rheological behavior were evaluated. It is shown that the resulting solutions are two-phase, and their morphology depends on the components' ratio and the system's history. The non-monotonous change in the viscosity with the PAN content indicates a specific interaction of cellulose and PAN in N-methylmorpholine-N-oxide solutions. The rheological behavior of mixed solutions allows for their processing in conditions identical to those of cellulose solutions. The introduction of PAN into the cellulose matrix promotes a decrease in the structural order in the system, affecting the membranes' transport properties. For composite membranes, it was found that with an increase in the content of the PAN phase, the retention of Remazol and Orange decreases, while the observed values are several times higher than those for cellulose membranes. The permeability of ethanol increases with increasing terpolymer content.
PubMed: 37505033
DOI: 10.3390/membranes13070667 -
Molecules (Basel, Switzerland) Apr 2023A series of new Morita-Baylis-Hillman acetates were prepared and reacted with methanesulfonamide (KCO, DMF, 23 °C) to produce tertiary dihydroquinoline sulfonamides in...
A series of new Morita-Baylis-Hillman acetates were prepared and reacted with methanesulfonamide (KCO, DMF, 23 °C) to produce tertiary dihydroquinoline sulfonamides in high yields. Subsequent efforts to eliminate the methylsulfonyl group from these derivatives (KCO, DMF, 90 °C) as a route to quinolines were met with mixed results. Although dihydroquinoline sulfonamides prepared from ethyl acrylate and acrylonitrile generally underwent elimination to give excellent yields of quinolines, those generated from 3-buten-2-one failed to undergo elimination and instead decomposed. The failure of these ketone substrates to aromatize presumably derives from the enolizable methyl ketone at C-3. Finally, the attempted aromatization of the acrylate-derived 6,7-difluoro-1,2-dihydroquinoline sulfonamide demonstrated that other interesting processes could occur in preference to the desired elimination.
PubMed: 37050020
DOI: 10.3390/molecules28073256 -
Chemosphere Feb 2020Persistent organic pollutants (POPs) released from plastics into water, soil and air are significant environmental and health problem. Continuous exposure of humans to... (Review)
Review
Persistent organic pollutants (POPs) released from plastics into water, soil and air are significant environmental and health problem. Continuous exposure of humans to these substances results not only from the slow biodegradation of plastics but also from their ubiquitous use as industrial materials and everyday products. Exposure to POPs may lead to neurodegenerative disorders, induce inflammation, hepatotoxicity, nephrotoxicity, insulin resistance, allergies, metabolic diseases, and carcinogenesis. This has spurred an increasing intense search for natural compounds with protective effects against the harmful components of plastics. In this paper, we discuss the current state of knowledge concerning the protective functions of polyphenols against the toxic effects of POPs: acrylonitrile, polychlorinated biphenyls, dioxins, phthalates and bisphenol A. We review in detail papers from the last two decades, analyzing POPs in terms of their sources of exposure and demonstrate how polyphenols may be used to counteract the harmful environmental effects of POPs. The protective effect of polyphenols results from their impact on the level and activity of the components of the antioxidant system, enzymes involved in the elimination of xenobiotics, and as a consequence - on the level of reactive oxygen species (ROS). Polyphenols present in daily diet may play a protective role against the harmful effects of POPs derived from plastics, and this interaction is related, among others, to the antioxidant properties of these compounds. To our knowledge, this is the first extensive review of in vitro and in vivo studies concerning the molecular mechanisms of interactions between selected environmental toxins and polyphenols.
Topics: Benzhydryl Compounds; Dioxins; Environmental Monitoring; Environmental Pollutants; Hazardous Substances; Humans; Metabolic Diseases; Phenols; Plastics; Polychlorinated Biphenyls; Polyphenols; Soil
PubMed: 31563713
DOI: 10.1016/j.chemosphere.2019.124901 -
International Journal of Molecular... May 2021Cutaneous melanoma represents one of the deadliest types of skin cancer. The prognosis strongly depends on the disease stage, thus early detection is crucial. New... (Review)
Review
Cutaneous melanoma represents one of the deadliest types of skin cancer. The prognosis strongly depends on the disease stage, thus early detection is crucial. New therapies, including BRAF and MEK inhibitors and immunotherapies, have significantly improved the survival of patients in the last decade. However, intrinsic and acquired resistance is still a challenge. In this review, we discuss two major aspects that contribute to the aggressiveness of melanoma, namely, the embryonic origin of melanocytes and melanoma cells and cellular plasticity. First, we summarize the physiological function of epidermal melanocytes and their development from precursor cells that originate from the neural crest (NC). Next, we discuss the concepts of intratumoral heterogeneity, cellular plasticity, and phenotype switching that enable melanoma to adapt to changes in the tumor microenvironment and promote disease progression and drug resistance. Finally, we further dissect the connection of these two aspects by focusing on the transcriptional regulators MSX1, MITF, SOX10, PAX3, and FOXD3. These factors play a key role in NC initiation, NC cell migration, and melanocyte formation, and we discuss how they contribute to cellular plasticity and drug resistance in melanoma.
Topics: Acrylonitrile; Aniline Compounds; Bridged Bicyclo Compounds, Heterocyclic; Cell Differentiation; Cell Movement; Cell Plasticity; Drug Resistance, Neoplasm; Forkhead Transcription Factors; Gene Expression Regulation, Neoplastic; MSX1 Transcription Factor; Melanocytes; Melanoma; Microphthalmia-Associated Transcription Factor; Neural Crest; PAX3 Transcription Factor; Phenotype; Pyrimidinones; SOXE Transcription Factors; Skin Neoplasms
PubMed: 34071193
DOI: 10.3390/ijms22115761 -
Polymers May 2022Plastic gears are mostly used in the textile, food, and automotive industries due to their silent operation, corrosion resistance, and light and cheap advantages....
Plastic gears are mostly used in the textile, food, and automotive industries due to their silent operation, corrosion resistance, and light and cheap advantages. Plastic gears are generally manufactured by injection molding or hobbing methods. The excess costs of the molds used to produce parts in injection molding and the problems of wastes that occur during production in hobbing lead companies to additive manufacturing, which is an alternative application. In the additive manufacturing method, the desired amount of product is produced without the problem of waste. In this study, the wear resistance of plastic spur gears produced by the Fused Deposition Modeling (FDM) method was determined theoretically. In order to determine the service life of gears, wear tests were carried out in the Forschungsstelle fur Zahnrader und Getriebebau (FZG) type test device at the same load and rotational speeds. polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), and polyethylene terephthalate (PETG) thermoplastic polymer materials were used in the production of gears. When the gears rotate at the same load and rotational speeds, the most wear was observed in ABS, PLA, and PETG at the theoretically calculated wear depths. PETG is the most resistant material in terms of wear.
PubMed: 35631946
DOI: 10.3390/polym14102064