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Lung injury and expression of p53 and p16 in Wistar rats induced by respirable chrysotile fiber dust from four primary areas of China Полный текст
2018
Zeng, Yali | Cui, Yan | Ma, Ji | Huo, Tingting | Dong, Faqin | Zhang, Qingbi | Deng, Jianjun | Zhang, Xu | Yang, Jie | Wang, Yulin
Chrysotile products were widely used in daily life, and a large amount of respirable dust was produced in the process of production and application. At present, there was seldom research on the safety of chrysotile fiber dust, and whether its long-term inhalation can lead to lung cancer was unknown. In order to determine whether respirable chrysotile fiber dust of China caused lung cancer, four major chrysotile-producing mine areas in China were selected for this study. Chrysotile fibers were prepared into respirable dust. Particle size was measured by laser particle analysis, morphology was observed by scanning electron microscope, chrysotile fiber phase was analyzed by X-ray diffraction, trace chemical elements were identified by X-ray fluorescence, and the structure and the active groups of the dust were determined after grinding by Fourier transform infrared spectroscopy. Male Wistar rats were exposed to non-exposed intratracheal instillation with different concentrations of chrysotile fiber dust. The rats were weighed after 1, 3, and 6 months, then the lung tissues were separated, the lung morphology was observed, and the pulmonary index was calculated. Pathological changes in lung tissues were observed by optical microscope after the HE staining of tissues, and the gene expression of p53 and p16 was determined by reverse transcription polymerase chain reaction. First, the results showed that the particle sizes of the four fibers were less than 10 μm. Four primary areas of chrysotile had similar fibrous structure, arranged in fascicles, or mixed with thin chunks of material. Second, the elementary composition of the four fibers was mainly chrysotile, and the structure and the active groups of the grinding dust were not damaged. Third, the weights of the treated rats were obviously lower, and the lung weights and the pulmonary index increased significantly (P < 0.05). Fourth, the treated Wistar rat lung tissues revealed different degrees of congestion, edema, inflammatory cell infiltration, and mild fibrosis. Fifth, the p53 and p16 genes decreased in the Mangnai group after 1 month of exposure, and the other groups increased. The expression of p53 and p16 in each group decreased significantly after 6 months (P < 0.05). In conclusion, the respirable chrysotile fiber dust from the four primary areas of China had the risk of causing lung injury, and these changes may be related to the physical and chemical characteristics of chrysotile from different production areas.
Показать больше [+] Меньше [-]Characterization and quality assessment of recycled post-consumption poly(ethylene terephthalate) (PET) Полный текст
2018
Masmoudi, Fatma | Fenouillot, Françoise | Mehri, Afef | Jaziri, Mohamed | Ammar, Emna
In the present study, the recycled post-consumption polyethylene terephthalate (PET) flakes were investigated as possible raw materials for the production of food packaging. After heating at 220 °C for 1 h, a steaming stage was conducted as a control test to assess the quality of the product. Different samples were characterized by ¹H-NMR, FT-IR, DSC/TGA analysis, viscosity index (VI), and trace metals analysis. The results showed that the recycled post-consumed PET flakes’ properties were generally conform to the standard norms of PET except the color of some flakes turned to yellow. Subsequently, a complementary study was undertaken to assess whether the material could be possibly reused for food packaging. For this purpose, rheological, thermal, and mechanical characterizations were performed. The results of the comparative study between the virgin and the recycled PET flakes concluded that the PET recycling affected the rheological properties but did not have any significant effect on their thermal and mechanical characteristics. Hence, it was deduced that the post-consumed PET flakes could be reused as a packaging material except food products.
Показать больше [+] Меньше [-]Pesticides in indoor and outdoor residential dust: a pilot study in a rural county of Taiwan Полный текст
2018
Hung, Chien-Che | Huang, Feng-Jung | Yang, Ya-Qing | Hsieh, Chia-Jung | Tseng, Chun-Chieh | Yiin, Lih-Ming
We conducted a pilot study to examine pesticides in dust of homes in a rural county of Taiwan. A total of 56 homes of pregnant women were included in the study. Indoor and outdoor dust was collected by a vacuum sampler and a dustpan/brush set, respectively. Nine pesticides were selected for analysis on gas chromatography-mass spectrometry with the detection limits being 0.088 ng/g or lower. The most detected pesticides were cypermethrin and chlorpyrifos, which appeared in 82.7 and 78.8% of indoor samples and 48.2 and 39.3% of outdoor samples, respectively. The detection of pesticides from indoor and outdoor dust, however, was not consistent, indicating different sources of pesticides. In addition to those two most detected, permethrin, prallethrin, and tetramethrin, which were common ingredients of insecticide products for indoor use, were also frequently found in indoor dust, suggesting that indoor use of such pesticide products may have been a major source. Fewer pesticides were found in outdoor dust, but the outdoor detection of chlorpyrifos was significantly associated with farms present inside the circles with radii of 50 and 100 m surrounding the homes (P = 0.021, 0.016). It is suggested that pesticide drift from agricultural areas to residential environments may have occurred. No seasonal effect on distribution of pesticides in dust was found, indicating that pesticides could be routinely used in Taiwan regardless of season. Compared with other international studies, this study shows relatively high levels of chlorpyrifos but low levels of pyrethroids (i.e., cypermethrin), reflecting a different pattern of pesticide use in Taiwan. Further studies need to be warranted for a better understanding of exposure to pesticides and the associated health effects.
Показать больше [+] Меньше [-]Application of blueberry anthocyanins reduces perfluorooctane sulfonate toxicity on planarians (Dugesia japonica) in locomotion, regeneration, and gene expression and contents Полный текст
2018
Zhao, Baoying | Shao, Xinxin | Zhao, Bosheng | Yuan, Zuoqing | Zhang, Jianyong
Perfluorooctane sulfonate (PFOS) which has been distributed worldwide is a persistent organic contaminant. Blueberry anthocyanins (ANT) are phytonutrients with antioxidant activities. The influence of different PFOS and ANT concentrations on the behavioral activities, regeneration of planarians (Dugesia japonica), and the expression levels and contents of Djnad6 and Djcox1 genes has been investigated. PFOS treatments affected the gene expression levels, induced a decrease in the planarians’ locomotor velocity, and increased the time required for the regeneration of the transverse amputated fragments in a time- and dose-dependent manner. Additionally, ANT treatments, to a certain extent, alleviated the damage caused by PFOS to planarians. ANT increased the planarians’ locomotor velocity and the percentage of regenerating planarians with eyespots and auricles. Furthermore, ANT alleviated the expression disorders of Djnad6 and Djcox1 induced by PFOS.
Показать больше [+] Меньше [-]Per- and polyfluoroalkyl substances in human breast milk and current analytical methods Полный текст
2018
Macheka-Tendenguwo, Linda R. | Olowoyo, Joshua O. | Mugivhisa, Liziwe L. | Abafe, Ovokeroye A.
Per- and polyfluoroalkyl substances (PFASs) have since become a major health concern as they have been reportedly found in human tissues, blood and breast milk. The main aim of the study was to review the current data on PFASs in human breast milk, including the challenges of analysis as well as the possible modes of transfer from maternal blood. In this paper, previously published data on the concentrations of PFASs in human breast milk from around the world were reviewed and summarised. Eligible studies with reference lists published before 1 June 2017 were included by searching several databases (including Scopus, ScienceOpen and SciFinder). From this search, studies with the number of participants in each study ranging from 2 to 1237 were identified. The review indicated that based on the structural profiles and concentration levels, there was variation in the geographical distribution of these compounds in breast milk. Although there are no recorded investigations on the modes of transfer from maternal blood to breast milk, literature suggests that the PFASs tend to be transferred through binding to various proteins. The review also examined the different sample preparation and analytical methods employed to measure the concentrations of PFASs in human breast milk. This showed that solid phase extraction was the most common extraction method. After extraction, liquid chromatography coupled with tandem mass spectrometry was the most common analysis method. Since several of these methods were initially dedicated to monitoring PFASs in food and water, they demonstrate some limitations with regard to specificity and sensitivity to human fluids. Additionally, there are currently no published records of certified reference materials and/or proficiency scheme devoted to standardising PFAS concentrations in breast milk.
Показать больше [+] Меньше [-]Physiological characterization of common bean (Phaseolus vulgaris L.) under abiotic stresses for breeding purposes Полный текст
2018
Lanna, Anna Cristina | Silva, Renato Adolfo | Ferraresi, Tatiana Maris | Mendonça, João Antônio | Coelho, Gesimária Ribeiro Costa | Moreira, Alécio Souza | Valdisser, Paula Arielle Mendes Ribeiro | Brondani, Claudio | Vianello, Rosana Pereira
In the Brazilian wet and dry seasons, common beans (Phaseolus vulgaris L.) are grown under rainfed conditions with unexpected episodes of drought and high temperatures. The objective of this study was to evaluate the physiological mechanisms associated with drought adaptation traits in landraces and line/cultivars of beans from the Andean and Mesoamerican gene pools. Twenty-five genotypes, contrasting in terms of drought tolerance, were evaluated in a phenotyping platform under irrigated and rainfed conditions. Agronomic and physiological parameters such as grain yield, shoot structures, gas exchange, water potential, and osmotic adjustment were evaluated. The stress intensity was estimated to be 0.57, and the grain yield reduction ranged from 22 to 89%. Seven accessions, representative of the Andean and Mesoamerican germplasm (CF 200012, CF 240056, CF 250002, CF 900004, CNF 4497, CNF 7382, and SEA 5), presented superior performance in grain yield with and without stresses. The physiological responses under abiotic stresses were highly variable among the genotypes, and two Mesoamerican accessions (CF 200012 and SEA 5) showed more favorable adaptive responses. As the main secondary physiological traits, gas exchange and osmotic adjustment should be evaluated together with the grain yield to increase the selection efficiency of abiotic stresses-tolerant common bean lines.
Показать больше [+] Меньше [-]Tracking long-distance atmospheric deposition of trace metal emissions from smelters in the upper Columbia River valley using Pb isotope analysis of lake sediments Полный текст
2018
Child, AndrewWright | Moore, BarryC. | Vervoort, JeffreyD. | Beutel, MarcW.
Heavy metal discharge from mining and smelting operations into aquatic ecosystems can cause long-term biological and ecological impacts. The upper Columbia River is highly contaminated with heavy metal wastes from nearby smelting operations in Trail, British Columbia, Canada, and to a lesser extent, Northport (Le Roi smelter), Washington, USA. Airborne emissions from the Trail operations were historically and are currently transported by prevailing winds down the Columbia River canyon, where particulate metals can be deposited into lakes and watersheds. In lakes, sediment cores contain records of past environmental conditions, providing a timeline of fundamental chemical and biological relationships within aquatic ecosystems, including records of airborne metal depositions. We analyzed trace metal concentrations (Ni, Cd, Zn, As, Cu, Sb, Pb, Hg) and Pb isotope compositions of sediment cores from six remote eastern Washington lakes to assess potential sources of atmospheric heavy metal deposition. Sediment cores displayed evidence to support trace metal loading as a direct consequence of smelting operations in Trail. Smelter contamination was detected 144 km downwind of the Trail Smelter. Cd, Sb, Pb (p < 0.001), and to a lesser extent As and Hg (p < 0.05) concentrations were correlated with Pb isotope compositions, suggesting that the Trail operations were likely the main source for these trace metals.
Показать больше [+] Меньше [-]Potential vulnerability of oak forests to climate change-induced flooding: effects of mild oxygen deficiency on Quercus robur and Quercus petraea seedling physiology Полный текст
2018
Bourgeade, Pascale | Bourioug, Mohamed | Macor, Sandra | Alaoui-Sossé, Laurence | Alaoui-Sossé, Badr | Aleya, Lotfi
Flooding is characterized by saturation of soil pores with water, leading to hypoxic conditions which affect plant root development and metabolism. We investigated the oxygen deficiency tolerance observed in Quercus robur and Quercus petraea and seek to understand whether it can be explained by enhanced efficiency in oxygen use in the roots, as estimated through radial oxygen loss visualization in relation to growth measurements and root apex respiration. The study showed that root growth, under oxygen deficiency conditions, was significantly reduced only in Q. robur seedlings. Root respiration was maintained in Q. robur, whereas it was decreased in Q. petraea. Both species set up a barrier against radial oxygen loss, though measurement of apex oxygen leakage showed greater oxygen efficiency in Q. robur seedlings. This strategy might allow Q. robur to maintain its respiration and thus to survive longer under oxygen deficiency conditions by facilitating the seedling establishment in transient flooded soils.
Показать больше [+] Меньше [-]The integrative effect of periphyton biofilm and tape grass (Vallisneria natans) on internal loading of shallow eutrophic lakes Полный текст
2018
Yang, Ying | Chen, Wei | Yi, Zhiyong | Pei, Guofeng
The response of periphyton biofilm and the submerged macrophyte tape grass (Vallisneria natans) to internal loading from eutrophic lake sediments were evaluated in microcosms. The sediments from the littoral zone and center of a lake were selected to carry out the microcosm experiment. To determine how the differences in the periphyton biofilm and V. natans growth alone or in combination, we measured changes in water quality, growth, and TP in the periphyton biofilm and V. natans in microcosms containing these sediments. The results showed that the average daily TN and TP removal rates were 32.6 and 35.4%, respectively, in the microcosms containing the lake center sediments by V. natans and the periphyton biofilm. The presence of the periphyton biofilm and V. natans increased the pH, dissolved oxygen, and redox potential and decreased the conductivity in the overlying water in all treatments. Compared to the state before the treatments, V. natans grew well, with a significant increase in biomass (3.1- to 5.5-fold growth) and TP amount (5.1- to 8.8-fold) in all treatments after 48 days. However, the growth of V. natans that combined with the periphyton biofilm was better than that of V. natans alone, as reflected by the dry weight, chlorophyll a content, malondialdehyde content, and TP amount. In conclusion, the periphyton biofilm was beneficial for the growth of V. natans, and the appropriate combination of V. natans and periphyton biofilm would be a potential method for the ecological restoration of eutrophic lakes.
Показать больше [+] Меньше [-]Biosorption of strontium ions from simulated high-level liquid waste by living Saccharomyces cerevisiae Полный текст
2018
Qiu, Liang | Feng, Jundong | Dai, Yaodong | Chang, Shuquan
In this study, the Saccharomyces cerevisiae (S. cerevisiae) was modified by γ-ray. The RNA-seq results reflect that the high γ-ray energies could change some gene fragments, such as deletion, recombination, and mutation. The biosorption of strontium ions (Sr²⁺) to different types of S. cerevisiae (S. cerevisiae (K-0), modified S. cerevisiae (Y-7), and non-living S. cerevisiae (H-K)) from the simulated high-level liquid waste (S-HLLW) was assessed at different experimental conditions. The sorption experimental results show that, under an appropriate condition, γ-ray radiation can enhance its biosorption capacity slightly of Sr²⁺ to S. cerevisiae. The maximum metal uptake and efficiency of Y-7 under S-HLLW were 11.656 mg g⁻¹ and 37.91% at 32 h (wet weight), respectively. They decreased to 9.46 mg g⁻¹ and 30.76% under radiation conditions. SEM-EDX and TEM analysis indicates that Sr²⁺ was adsorbed both on the cellular surface and the inner parts of the cells. Our experimental results fit well to the Langmuir and Freundlich model isotherms (r² > 0.94), and the maximum biosorption capacity values reached qₘₐₓ > 24.74 mg g⁻¹ at 32 °C. Negative values of ΔG⁰ and positive values of ΔH⁰ were observed, indicating the spontaneous and endothermic nature of Sr²⁺ biosorption on modified S. cerevisiae. The biosorption kinetics follow a pseudo-second-order equation at 32 °C (r² > 0.94). The desorption efficiency of Sr²⁺ adsorbed onto Y-7 was 7.65 ± 0.52%, 76.51 ± 2.13%, and 65.62 ± 2.42% by deionized water, 1 M HCl, and 0.1 M EDTA-Na, respectively. However, they were lower than H-K (18.82, 83.32, and 73.32%). Our findings demonstrate that living S. cerevisiae (Y-7) is a promising sorbent material for the treatment of radioactive process streams.
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