Zobrazení zdroje stránky Rosskelleher3629

Quantitative source contributions reveal that high amounts of most of the metals are derived from a combination of brake wear and geogenic particles, the latter of which are likely resuspended by moving vehicles. This emphasizes the importance of non-exhaust particles connected to road traffic. Once a source identification has been performed for an area of interest, classification models can be applied to assess air quality for further samples from within the whole study area, offering a tool for air quality assessment. The general validity of this approach is demonstrated using samples from other locations.Six ecotypes of Typha domingensis Pers. Jahlar (E1), Sheikhupura (E2), Sahianwala (E3), Gatwala (E4), Treemu (E5) and Knotti (E6) from different ecological regions were collected to evaluate the leaf anatomical and biochemical attributes under different levels of salinity and nickel stress viz; L0 (control), L1 (100 mM + 50 mg kg-1), L2 (200 mM + 100 mg kg-1) and L3 (300 mM + 150 mg kg-1). Presence of salt and Ni in rooting medium consistently affected growth, anatomical and physio-biochemical attributes in all Typha ecotypes. Discrete anatomical modifications among ecotypes such as reduced leaf thickness, increased parenchyma area, metaxylem cell area, aerenchyma formation and improved metaxylem vessels were recorded with increasing dose of salt and Ni. The minimum anatomical damages were recorded in E1 and E6 ecotypes. In all ecotypes, progressive perturbations in ionic homeostasis (Na+, K+, Cl-, N) due to salt and metal toxicity were evident along with reduction in photosynthetic pigments. Maximum enhancement in Catalase (CAT), Superoxide dismutase (SOD), Peroxidase (POD) and modulated Malondialdehyde (MDA) activity was recorded in E1 and E6 as compared to other ecotypes. Accumulation of large amounts of metabolites such as total soluble sugars, total free amino acids content in Jahlar, Knotti, Treemu and Sahianawala ecotypes under different levels of salt and Ni prevented cellular damages in T. domingensis Pers. The correlation analysis exhibited a close relationship among different levels of salinity and Ni with various plant attributes. PCA-Biplot verified our correlational analysis among various attributes of Typha ecotypes. An obvious separation of Typha characters in response to different salinity and Ni levels was exhibited by PC1. We recommend that genetic potential of T. domingensis Pers. To grow under salt and Ni stresses must be investigated and used for phytoremediation and reclamation of contaminated soil.Potential health benefits from improved ambient air quality during the COVID-19 shutdown have been recently reported and discussed. Despite the shutdown measures being in place, northern China still suffered severe haze episodes (HE) that are not yet fully understood, particularly how the source emissions changed. Thus, the meteorological conditions and source emissions in processing five HEs occurred in Beijing-Tianjin-Hebei area were investigated by analyzing a comprehensive real-time measurement dataset including air quality data, particle physics, optical properties, chemistry, aerosol lidar remote sensing, and meteorology. Three HEs recorded before the shutdown began were related to accumulated primary pollutants and secondary aerosol formation under unfavorable dispersion conditions. The common "business as usual" emissions from local primary sources in this highly polluted area exceeded the wintertime atmospheric diffusive capacity to disperse them. Thus, an intensive haze formed under these adverse meteorological conditions such as in the first HE, with coal combustion to be the predominant source. Positive responses to the shutdown measures were demonstrated by reduced contributions from traffic and dust during the final two HEs that overlapped the Spring and Lantern Festivals, respectively. [https://www.selleckchem.com/products/methyl-b-cyclodextrin.html Methyl-β-cyclodextrin cost] Local meteorological dispersion during the Spring Festival was the poorest among the five HEs. Increased residential burning plus fireworks emissions contributed to the elevated PM2.5 with the potential of enhancing the HEs. Our results highlight that reductions from shutdown measures alone do not prevent the occurrence of HEs. To further reduce air pollution and thus improve public health, abatement strategies with an emphasis on residential burning are needed.Developing low-cost and high-performance biosorbent for water purification continues drawing more and more attention. In this study, cellulose-chitosan composite hydrogels were fabricated via a co-dissolution and regeneration process using a molten salt hydrate (a 60 wt% aqueous solution of LiBr) as a solvent. The addition of chitosan not only introduced functionality for metal adsorption but also increased the specific surface area and improved the mechanical strength of the composite hydrogel, compared to pure cellulose hydrogel. Batch adsorption experiments indicated that the composite hydrogel with 37% cellulose and 63% chitosan exhibited an adsorption capacity of 94.3 mg/g (1.49 mmol/g) toward Cu2+ at 23 °C, pH 5, and initial metal concentration of 1500 mg/L, which was 10 times greater than the adsorption capacity of pure cellulose hydrogel. Competitive adsorption from a mixed metals solution revealed that the cellulose-chitosan composite hydrogel exhibited selective adsorption of the metals in the order of Cu2+ &gt; Zn2+ &gt; Co2+. This study successfully demonstrated an innovative method to fabricate biosorbents from abundant and renewable natural polymers (cellulose and chitosan) for removing metal ions from water.Several environmental pollutants, including pesticides, herbicides and persistent organic pollutants play an important role in the development of chronic diseases. However, most studies have examined environmental pollutants toxicity in target organisms or using a specific toxicological test, losing the real effect throughout the ecosystem. In this sense an integrative environmental risk of pollutants assessment, using different model organisms is necessary to predict the real impact in the ecosystem and implications for target and non-target organisms. The objective of this study was to use alachlor, a chloroacetanilide herbicide responsible for chronic toxicity, to understand its impact in target and non-target organisms and at different levels of biological organization by using several model organisms, including membranes of dipalmitoylphosphatidylcholine (DPPC), rat liver mitochondria, bacterial (Bacillus stearothermophilus), plant (Lemna gibba) and mammalian cell lines (HeLa and neuro2a). Our results demonstrated that alachlor strongly interacted with membranes of DPPC and interfered with mitochondrial bioenergetics by reducing the respiratory control ratio and the transmembrane potential.