SciCombinator

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Concept: Vinyl chloride

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Vinyl chloride monomer (VCM) is widely used in the production of polyvinyl chloride (PVC) plastics. VCM is recognized as a confirmed human and animal carcinogenic compound. Recent studies have reported poor health of plastic workers, even having exposure at concentrations below the permissible limit to VCM. There has not been any study regarding exposed workers to VCM in Iran. Similarly, no information exists as to the biological monitoring of such workers. The main purpose of this study was to conduct a thorough occupational and biological monitoring of Iranian plastic workers exposed to VCM.A total of 100 workers from two plastic manufacturing plants (A and B) in Tehran along with 25 unexposed workers as controls were studied. The personal monitoring of all nonsmoking workers exposed to VCM at two plastic manufacturing plants (A and B) was performed in the morning shift (8 a.m. to 4 p.m.) according to the National Institute For Occupational Safety And Health method no. 1007.Biological monitoring of workers was carried out through collection of exhaled breath of all exposed and control workers in Tedlar bags and with a subsequent analysis using gas chromatography-flame ionization detector.Not only the mean occupational exposure of workers to VCM at plant A was higher than the respective threshold limit value but also the statistical significance was higher than workers at plant B. Similarly, VCM concentration in exhaled breath of workers at plant A was also statistically significantly higher than at plant B. Correlation of occupational exposure of all workers to vinyl chloride with its concentration in exhaled breath was statistically significant.This is the first study on biological monitoring for exposed plastic workers to VCM using exhaled breath. On the basis of the results in this study, a novel method of biological monitoring of plastic workers was proposed.

Concepts: Plastic, Chlorine, Occupational safety and health, Polyvinyl chloride, Vinyl, Vinyl chloride, 1,2-Dichloroethane, Henri Victor Regnault

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Infusion sets designed for peristaltic finger smart pumps (PFSPs) are necessary for the pumps' accurate handling. We previously found that medication dispensing is occasionally incomplete following the calculated infusion time when using certain combinations of PFSPs and infusion sets at a Japanese hospital. Thus, in this study, we investigated the cause of this observed delay by determining the effect of infusion set attachment technique on dispensing time using a combination of three kinds of PFSPs and five kinds of polyvinyl chloride (PVC) and polybutadiene (PB) infusion sets.

Concepts: Polyvinyl chloride, Vinyl chloride

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The concentrations and fluxes of airborne phthalates were measured from five types of polyvinyl chloride (PVC) consumer products (vinyl flooring, wallcovering, child’s toy, yoga mat, and edge protector) using a small chamber (impinger) system. Airborne phthalates released from each of those PVC samples were collected using sorbent (Tenax TA) tubes at three temperature control intervals (0, 3, and 6 h) under varying temperature conditions (25, 40, and 90 °C). A total of 11 phthalate compounds were quantified in the five PVC products examined in this study. To facilitate the comparison of phthalate emissions among PVC samples, their flux values were defined for total phthalates by summing the average fluxes of all 11 phthalates generated during the control period of 6 h. The highest flux values were seen in the edge protector sample at all temperatures (0.40 (25 °C), 9.65 (40 °C), and 75.7 μg m-2 h-1 (90 °C)) of which emission was dominated by dibutyl isophthalate. In contrast, the lowest fluxes were found in wallcovering (0.01 (25 °C) and 0.05 μg m-2 h-1 (40 °C)) and child’s toy (0.23 μg m-2 h-1 (90 °C)) at each temperature level. The information regarding phthalate composition and emission patterns varied dynamically with type of PVC sample, controlled temperature, and duration of control.

Concepts: Plastic, Plasticizer, Polyvinyl chloride, Vinyl, Bis(2-ethylhexyl) phthalate, The Edge, Vinyl chloride, Vinyl polymer

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Composites of polyvinyl chloride (PVC) with 2% calcium carbonate, 2% diethyl phthalate, 2% paraffin wax and 2% lead sulfate and different contents of antimony trioxide (Sb2O3) prepared by melting and irradiated with gamma-ray have been considered. Assessment of the mechanical and thermal properties of the unirradiated and irradiated FPVC were completed utilizing elasticity (TS), Elongation at break (Eb) and TGA measurements. TS and thermal stability of FPVC displayed advanced improvement after addition of additives and this approach highlighted the efficiency of those ingredients on PVC. The compounding of FPVC with Sb2O3in various extents was examined by FTIR, X-ray diffraction and SEM methods. It is obviously that the presence of Sb2O3begins impacting oxidative degradation leading to decrease in mechanical properties up to 10%. Moreover, slightly increase in the thermal stability of composites by exposure to ionizing radiation is apparently due to cross-linking of FPVC chains.

Concepts: Ionizing radiation, X-ray, Plastic, Lead, Thermoplastic, Polyvinyl chloride, Vinyl, Vinyl chloride

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There is a risk of drug sorption into an intravenous administration set composed of polyvinyl chloride (PVC), polyurethane (PU), or polyolefin (PO). This has implications on the dose of the active ingredient the patient receives, and thus therapeutic success. This study aimed to determine the plasma concentration of nitroglycerin and the effect of nitroglycerin on patients based on the composition of the administration set.

Concepts: Pharmacology, Patient, Illness, Polymerization, Plastics, Thermoplastic, Polyvinyl chloride, Vinyl chloride

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Di-(2-propylheptyl) phthalate (DPHP) is a plasticizer used in polyvinyl chloride and vinyl chloride copolymer that has been suggested to be a toxicant in rats and may affect human health. Because the use of DPHP is increasing, the general German population is being exposed to DPHP. Toxicant metabolism is important for human toxicant exposure assessments. To date, the knowledge regarding DPHP metabolism has been limited, and only four metabolites have been identified in human urine. Ultra-performance liquid chromatography was coupled with Orbitrap high-resolution mass spectrometry (MS) and two data-screening approaches-the signal mining algorithm with isotope tracing (SMAIT) and the mass defect filter (MDF)-for DPHP metabolite candidate discovery. In total, 13 and 104 metabolite candidates were identified by the two approaches, respectively, in in vitro DPHP incubation samples. Of these candidates, 17 were validated as tentative exposure biomarkers using a rat model, 13 of which have not been reported in the literature. The two approaches generated rather different tentative DPHP exposure biomarkers, indicating that these approaches are complementary for discovering exposure biomarkers. Compared with the four previously reported DPHP metabolites, the three tentative novel biomarkers had higher peak intensity ratios, and two were confirmed as DPHP hydroxyl metabolites based on their MS/MS product ion profiles. These three tentative novel biomarkers should be further investigated for potential application in human exposure assessment.

Concepts: Metabolism, Mass spectrometry, Analytical chemistry, Metabolomics, Plasticizer, Polyvinyl chloride, Vinyl, Vinyl chloride

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N-Doped mesoporous carbon extrudate with a major quaternary N species has been successfully prepared through direct carbonization of wheat flour/gluten with silica, which is a cheap and convenient method for scale-up production approach. The obtained carbon extrudate metal-free catalyst enables highly efficient production of vinyl chloride monomer through acetylene hydrochlorination, with a superior catalytic performance and excellent stability (>85% conversion and vinyl chloride selectivity over 99% at 220 °C).

Concepts: Enzyme, Hydrogen, Catalysis, Hydrogen chloride, Vinyl, Vinyl chloride

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Most studies to date confirm that any increase in the needle insertion force increases the damage to the tissue. When it comes to brain tissue, even minor damage can cause a long-lasting traumatic brain injury. Thus there is a great demand for innovative minimally invasive needles among the medical community. In our previous studies a novel bioinspired needle design with specially designed barbs was used to perform insertion tests into Polyvinyl chloride (PVC) tissue-mimicking gels, in which it decreased the insertion force by as much as 25%.

Concepts: Medicine, Brain, Traumatic brain injury, Tissues, Minimally invasive, Microsoft, Polyvinyl chloride, Vinyl chloride

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The focus of this paper is to present new designs of innovative bioinspired needles to be used during percutaneous procedures. Insect stingers have been known to easily penetrate soft tissues. Bioinspired needles mimicking the barbs in a honeybee stinger were developed for a smaller insertion force, which can provide a less invasive procedure. Decreasing the insertion force will decrease the tissue deformation, which is essential for a more accurate targeting. In this study, some design parameters, in particular, barb shape and geometry (i.e., front angle, back angle, and height) were defined and their effects on the insertion force were investigated. Three-dimensional (3D) printing technology was used to manufacture bioinspired needles. A specially-designed insertion test setup using tissue mimicking Polyvinyl chloride (PVC) gels was developed to measure the insertion and extraction forces. The barb design parameters were then experimentally modified through detailed experimental procedures to further reduce the insertion force. Different scales of the barbed needles were designed and used to explore the size-scale effect on the insertion force. To further investigate the efficacy of the proposed needle design in real surgeries, preliminary ex-vivo insertion tests into bovine liver tissue were performed. Our results show that the insertion force of the needles in different scales decreased by 21-35% in PVC gel insertion tests and by 46% in bovine liver tissue insertion tests.

Concepts: Effectiveness, Tissues, Design, Polyvinyl chloride, Vinyl chloride

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Di(2-ethylhexyl)phthalate (DEHP), a widely used plasticizer, mainly serves as an additive to render polyvinyl chloride (PVC) soft and flexible. PVC plastics have become ubiquitous in our modern society. Yet, the leaching of DEHP from PVC-based consumables ultimately results in the deposition in certain tissues via inadvertent applications. Health risks for human populations exposed to DEHP has been assumed by studies on rodents and other species, including the DEHP-induced developmental dysregulation, reproductive impairments, tumorigenesis, and diseases in a transgenerational manner. In this review, we comprehensively summarize the accumulated literature regarding the multifaceted roles of DEHP in the activation of the nuclear receptors, the alteration of the redox homeostasis, epigenetic modifications and the acquisition of chemoresistance.

Concepts: Human, Plastic, Plastics, Plasticizer, Polyvinyl chloride, Bis(2-ethylhexyl) phthalate, Vinyl chloride, Plastic recycling