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Properties and characterization of thyme essential oil incorporated collagen hydrolysate films extracted from hide fleshing wastes for active packaging Full text
2020
Ocak, Bugra
In this investigation, collagen hydrolysate (CH) films extracted from hide fleshing wastes were successfully developed using solvent casting method by incorporating different concentrations of thyme essential oil (TO) (2%, 4%, 6%, and 8%) into the CH. Depending on the concentration of TO, thickness, tensile strength (TS), elongation at break (EAB), film solubility (FS), color, opacity, light transmittance, and thermal properties varied. Addition of TO resulted in the increases in the thickness, EAB (%), and light barrier performance of CH–TO films while there was a significant decrease in TS and FS of the CH films (p ≤ 0.05). According to our findings, the increment of TO content induced higher lightness and yellowness but lower redness values compared to CH film. Fourier-transform infrared spectroscopy was conducted to determine the molecular changes and interactions between CH extracted from hide fleshing wastes and TO. In order to analyze the thermal behavior of the films, differential scanning calorimetry analysis was conducted. Moreover, the structure–property relationships of CH and TO were examined by scanning electron microscopy and a reduction in the compact and homogenous structures of the films containing TO was observed. Promising results have been obtained showing that CH-based films can be used for active packaging purposes, thereby contributing to a significant reduction in the environmental impact of both leather solid waste and plastic packaging materials.
Show more [+] Less [-]Chlorpyrifos levels within permitted limits induce nuclear abnormalities and DNA damage in the erythrocytes of the common carp Full text
2020
Mitkovska, Vesela | Chassovnikarova, Tsenka
The organophosphate pesticide chlorpyrifos (CPF) is defined as a priority pollutant in surface freshwaters according to Directive 2013/39/EU of the European Parliament. The focus of this study was to assess the potential cytotoxic and genotoxic effects of permissible CPF levels on juvenile forms of the common carp. We found that low-level CPF exposure did not induce elevated levels of micronuclei, but significantly increased the frequency of total nuclear abnormalities (NAs) proportional to dose and time; notched, blebbed, lobed and eight-shaped nuclei, nuclear buds, nuclear bridges and binucleated cells were all detected. Decreased frequencies of polychromatic erythrocytes (PCEs) and DNA damage detected by comet assay were also observed, confirming the cytotoxic and genotoxic effects of CPF. Altogether, these data (1) demonstrate that CPF is toxic even at permissible levels, possessing considerable genotoxic and cytotoxic potential in peripheral erythrocytes of exposed fish and (2) validate the assessment of NAs, PCEs and comet assay performance as sensitive biomarkers for the early detection of CPF pollution. These findings can be applied to guide environmental risk assessment and biomonitoring programs.
Show more [+] Less [-]Supported-catalyst CuO/AC with reduced cost and enhanced activity for the degradation of heavy oil refinery wastewater by catalytic ozonation process Full text
2020
Wang, Weixing | Yao, Hong | Yue, Lingzhi
In this work, activated carbon-supported copper(II) oxide (CuO/AC) was prepared and used to degrade heavy oil refinery wastewater (HORW) by catalytic ozonation with the aim to develop low-cost and high-efficient supported-catalysts for degrading real recalcitrant industrial wastewater. Supported-catalyst CuO/AC was characterized by X-ray diffraction (XRD), N₂-physisorption, scanning electronic microscope (SEM), transmission electron microscope (TEM), and X-ray fluorescence (XRF). The degradation was mainly evaluated by chemical oxygen demand (COD), total organic carbon (TOC), 5-day biochemical oxygen demand (BOD₅), biodegradability and toxicity. Compared with unsupported-catalyst CuO or the mixed system of activated-AC and unsupported-catalyst CuO, supported-catalyst CuO/AC with reduced cost exhibited significantly enhanced activity for degrading HORW (5.0 g CuO-5%/AC, 90 mg/L O₃, and 7.3 pH). TEM analysis showed that the high activity of supported-catalyst CuO-5%/AC might be ascribed to the fact that CuO particles were small and highly dispersed on AC. Mass spectrum spectrometry (MS) analysis revealed that the organic components in HORW were first degraded to small molecule oxidation products, which were then oxidized or mineralized further. The influence of CuO loading, CuO/AC dose, ozone dose and initial pH on the degradation efficiency was also investigated. The results of the present work showed that CuO/AC could be a promising supported-catalyst for catalyzing ozonation degradation of HORW.
Show more [+] Less [-]Histopathologic, apoptotic and autophagic, effects of prenatal bisphenol A and/or di(2-ethylhexyl) phthalate exposure on prepubertal rat testis Full text
2020
Balci, Aylin | Ozkemahli, Gizem | Erkekoglu, Pınar | Zeybek, Naciye Dilara | Yersal, Nilgun | Kocer-Gumusel, Belma
Bisphenol A (BPA) and di(2-ethylhexyl) phthalate (DEHP) are endocrine-disrupting chemicals (EDCs) used in a wide variety of industrial products as plasticizers. Exposure to EDCs, particularly in mixtures, in prenatal and early postnatal periods may lead to unwanted effects and can cause both developmental and reproductive problems. In this study, we aimed to determine the individual and combined effects of prenatal and lactational exposure to BPA and/or DEHP on testicular histology, apoptosis, and autophagic proteins. Pregnant Sprague-Dawley rats (n = 3) were divided into four groups (control, BPA (50 mg/kg/day), DEHP (30 mg/kg/day), and BPA (50 mg/kg/day) + DEHP (30 mg/kg/day)) and dosed by oral gavage during pregnancy and lactation. The male offspring (n = 6) from each group were chosen randomly, and their testicular examinations were performed on the twelfth week. The results showed that fetal and neonatal exposure to BPA and DEHP could lead to significant testicular histopathological alterations and cause increases in apoptosis markers (as evidenced by increases in caspase 3 and caspase 8 levels; increased TUNEL-positive spermatogonia and TUNEL-positive testicular apoptotic cells) and autophagic proteins (as evidenced by increased LC3 and Beclin levels and decreased p62 levels) in testicular tissue. We can suggest that EDCs cause more dramatic changes in both testicular structure and cell death when there is combined exposure.
Show more [+] Less [-]Spatial distribution of endemic fluorosis caused by drinking water in a high-fluorine area in Ningxia, China Full text
2020
Li, Mingji | Qu, Xiangning | Miao, Hong | Wen, Shengjin | Hua, Zhaoyang | Ma, Zhenghu | He, Zhirun
Endemic fluorosis is widespread in China, especially in the arid and semi-arid areas of northwest China, where endemic fluorosis caused by consumption of drinking water high in fluorine content is very common. We analyzed data on endemic fluorosis collected in Ningxia, a typical high-fluorine area in the north of China. Fluorosis cases were identified in 539 villages in 1981, in 4449 villages in 2010, and in 3269 villages in 2017. These were located in 19 administrative counties. In 2017, a total of 1.07 million individuals suffered from fluorosis in Ningxia, with more children suffering from dental fluorosis and skeletal fluorosis. Among Qingshuihe River basin disease areas, the high incidence of endemic fluorosis is in Yuanzhou District and Xiji County of Guyuan City. The paper holds that the genesis of the high incidence of endemic fluorosis in Qingshui River basin is mainly caused by chemical weathering, evaporation and concentration, and dissolution of fluorine-containing rocks around the basin, which is also closely related to the semi-arid geographical region background, basin structure, groundwater chemical characteristics, and climatic conditions of the basin. The process of mutual recharge and transformation between Qingshui River and shallow groundwater in the basin is intense. There is a close coupling relationship between the power of central and southern Ningxia disease areas and Qingshui River watershed of excess fluorine water. Because the traditional drinking water source of the residents in the basin is shallow groundwater, the underground water is the main cause of the high incidence of endemic fluorosis. The results show that Xiji County and Yuanzhou District were the areas of high incidence of endemic fluorosis which gradually decreased to the middle and lower reaches of Qingshui River. In space, distribution characteristics are Qingshui River source area > Qingshui River valley basin area, tributary area > trunk stream area, upstream area > middle reaches area> downstream area of Qingshui River. This is relatively consistent with the spatial distribution of fluoride ion content in Qingshui River groundwater.
Show more [+] Less [-]Effects of cleaning procedures on the long-term corrosion behavior of bronze artifacts of the cultural heritage in outdoor environment Full text
2020
Petiti, Chiara | Toniolo, Lucia | Gulotta, Davide | Mariani, Bruna | Goidanich, Sara
The cleaning of metallic artworks is a crucial step for their preservation. Cleaning operations generally aim at removing deposits and corrosion layers, and all the non-stable and potentially reactive phases formed as a consequence of the interaction of the metal with the environment. Thus, all secondary-formed compounds and layers that can undermine the overall preservation of the artwork, both from the esthetic and the corrosion point of view, should be removed. On the other hand, superficial stable patinas contributing to the artistic and historic value of the objects and that may provide protection to the metallic surface should be preserved. The optimal cleaning procedure should be able to promote a long-term improvement of the corrosion resistance of the surfaces. Therefore, the long-term monitoring of the corrosion behavior of the cleaned surfaces with electrochemical techniques could provide valuable information for the selection of the optimal methodology. In this work, five cleaning procedures have been applied to five bronze sculptures. The cleaned surfaces have been characterized following a multi-analytical and non-invasive approach, and the long-term evolution of their corrosion behavior has been monitored by means of on-site non-invasive linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) measurements for more than 2 years.
Show more [+] Less [-]Multi-objective optimized scheduling model for hydropower reservoir based on improved particle swarm optimization algorithm Full text
2020
Fang, Ruiming | Popole, Zouthi
In order to make hydropower station’s development and operation harmonious with ecological protection, the optimal operation of hydropower stations to meet the needs of ecological protection is studied. Firstly, the ecological protection function of river course is defined according to the minimum ecological runoff and suitable ecological runoff. Then, a multi-objective optimal running model of reservoir which can maximize the capacity of ecological protection and generation is proposed. Finally, an improved multi-objective particle swarm optimization algorithm (MOPSO), which can construct a neighborhood for each particle and choose the neighborhood optimal solution by adopting self-organizing mapping (SOM) method, is proposed to solve the model. The model is applied to the Shui-Kou Hydropower Station in Minjiang, China. The results show that the model can get the optimal schedule with balanced consideration of ecological benefits and power generation benefits, which has not a great impact on the economic benefits of reservoirs while achieving the goal of ecological environment. The research results can provide theoretical basis and concrete scheme reference for reservoir operation.
Show more [+] Less [-]Pro-inflammatory or anti-inflammatory effects of pulsed magnetic field treatments in rats with experimental acute inflammation Full text
2020
Mert, Tufan | Yaman, Selma
In this study, we evaluated the possible effects of sequenced pulsed magnetic fields (PMF) of 1-mT treatments with designed different frequencies (PMF-1—1, 3, 5, 7 Hz or PMF-2—7, 9, 12, 14 Hz) on the inflammatory signs such as abnormal pain behaviors, hyperalgesia and allodynia, edema, and fever in carrageenan (CG)-induced hind paw inflammation model in rats. Paw tissues were also histologically examined. PMF exposure was applied 3 times in 24 h. CG injection gradually decreased the thermal latencies and mechanical threshold and caused significant increases in temperature and mass of paw. PMF treatments significantly reduced the temperature and mass in the paw of rats with inflammation. PMF-1 treatments caused significant increases in the latencies and thresholds. However, administration of PMF-2 treatment was significantly decreased the latency and threshold. Furthermore, the histological pieces of evidence also suggested the anti-inflammatory effects of PMF-1 treatments or inflammatory actions of PMF-2 treatments. Findings presented in this paper suggest that 1-mT PMF treatments may have anti-edematous and antipyretics activities in inflamed rats. However, the effects of PMF treatments on abnormal pain hypersensitivities may be different. PMF treatments may make inflammatory pain relief or worse in inflamed rats depending on the PMF frequencies in sequence.
Show more [+] Less [-]Assessment of kidney health and exposure to mixture pollutants in the Mexican indigenous population Full text
2020
Díaz de León Martínez, Lorena | Ortega-Romero, Manolo | Grimaldo-Galeana, José Moisés | Barbier, Olivier | Vargas-Berrones, Karla | García-Arreola, María Elena | Rodriguez-Aguilar, Maribel | Flores Ramírez, Rogelio
The indigenous population is one of the most vulnerable to suffer from contaminated environments. One of the target organs to suffer early deterioration from exposure to toxins is the kidney. The objective of this article was to evaluate biomarkers of exposure to organic and inorganic toxins and biomarkers of early kidney damage in urine from an indigenous Tenek population in Mexico. The biomarkers of exposure were Li, Be, Al, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Mo, Sn, Ba, and Pb evaluated by ICP-MS and hippuric acid for toluene exposure evaluated by UV-coupled with liquid chromatography; the biomarkers of kidney damage were cystatin C (Cys-C), osteopontin (OPN), retinol-binding protein-4 (RPB-4), and neutrophil gelatinase-associated lipocalin (NGAL). Thirty-one urine samples were obtained from indigenous people; 16, 42, 45.1, and 45.2% of the population exceeded the reference values for Pb, Zn, As, and hippuric acid respectively. Our results demonstrate significant correlations between the metals tested and the proteins associated with renal damage; Cys-C, OPN, and RPB4 showed a significant correlation with Li, B, and Mo, as well as hippuric acid in the case of Cys-C and Zn in OPN and RPB-4; NGAL did not present significant correlations with any of the pollutants of the study. This pilot study contributes to the evidence of great inequity in health associated to environmental pollution matters faced by indigenous people and addresses the need of initiatives for mitigation under the perspective that health is a fundamental human right.
Show more [+] Less [-]Microplastic ingestion by tadpoles of pond-breeding amphibians—first results from Central Europe (SW Poland) Full text
2020
Kolenda, Krzysztof | Kuśmierek, Natalia | Pstrowska, Katarzyna
Microplastics (MPs) are one of the major threats to aquatic ecosystems. Surprisingly, our knowledge of its occurrence and its impact on the organisms that dwell in small water bodies is still scarce. The aim of this study was to investigate the occurrence and chemical composition of MPs in tadpoles of pond-breeding amphibians. In total, 201 tadpoles belonging to 5 species were collected from 8 ponds located in southwestern Poland. MPs were found in all examined sites and in all studied species. Among those tested, 53 (26%) tadpoles ingested a total of 71 MPs. IR-ATR analysis revealed that particles were of anthropogenic origin and included nylon, polyurethane, polyisoprene and 1,2 polybutadiene.
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