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Результаты 4801-4810 из 6,560
Evaluating the size distribution characteristics and sources of atmospheric trace elements at two mountain sites: comparison of the clean and polluted regions in China Полный текст
2020
Liu, Zirui | Hu, Bo | Yang, Yongjie | Zhang, Deqiang | Li, Wei | Wen, Tianxue | Xin, Jinyuan | Wang, Yuesi
Size-resolved trace metal concentrations at two background sites were assessed during a 1-year observation campaign, with the measurements performed in parallel at two mountain sites, where Mt. Dinghu (DHS) located in the rural region of Pearl River Delta (PRD) and Mt. Gongga (GGS) located in the Tibetan Plateau region. In total, 15 selected trace elements (Mg, Al, K, V, Mn, Fe, Cu, Zn, As, Mo, Ag, Cd, Ba, Tl, and Pb) in aerosol samples were determined using inductively coupled plasma mass spectrometry (ICPMS). The major metals in these two mountain sites were Fe, K, Mg, and Ca with concentrations ranging between 241 and 1452 ng/m³, 428 and 1351 ng/m³, 334 and 875 ng/m³, and 376 and 870 ng/m³, respectively, while the trace metals with the lowest concentrations were Mo, Ag, Cd, and Tl with concentrations lower than 4 ng/m³ in DHS and 2 ng/m³ in GGS. The pronounced seasonal variability in the trace elements was observed in DHS, with lower concentrations in spring and summer and relatively high in winter and autumn, whereas seasonal variance of trace elements is hardly observed in Mt. Gongga. The size distribution pattern of crustal elements of Al, Mg, K, Ba, and Fe was quite similar in DHS and GGS, which were mainly found in coarse particles peaked at 4.7–5.8 μm. In addition, V, Mo, Ag, and Tl were also concentrated in coarse particles, although the high enrichment factor (EF > 100) of which suggested anthropogenic origin, whereas trace metals of Cd, Mn, Zn, As, Cu, and Pb concentrated in fine mode particles. Specifically, these trace metals peak at approximately 1.5 μm in DHS, while those in GGS peaked at diameter smaller than 0.3 μm, indicating the responsible for long-range transport from the far urban and industrialized areas. Multivariate receptor model combined with the enrichment factor results demonstrated that the trace elemental components at these two background sites were largely contributed from the fossil fuel combustion (55.4% in DHS and 44.0% in GGS) and industrial emissions factors (20.1% vs. 26.5%), which are associated with long distance transport from the coastal area of Southeast China and the Northwestern India, respectively, as suggested by the backward air mass trajectory analysis. Local sources from soil dust contributed a minor variance for trace elements in DHS (9.7%) and GGS (13.8%), respectively.
Показать больше [+] Меньше [-]The influence of association of plant growth-promoting rhizobacteria and zero-valent iron nanoparticles on removal of antimony from soil by Trifolium repens Полный текст
2020
Daryabeigi Zand, Ali | Tabrizi, Alireza Mikaeili | Heir, Azar Vaezi
Using association of plants, nanomaterials, and plant growth-promoting bacteria (PGPR) is a novel approach in remediation of heavy metal-contaminated soils. Co-application of nanoscale zerovalent iron (nZVI) and PGPR to promote phytoremediation of Sb-contaminated soil was investigated in this study. Seedlings of Trifolium repens were exposed to different regimes of nZVI (0, 150, 300, 500, and 1000 mg/kg) and the PGPR, separately and in combination, to investigate the effects on plant growth, Sb uptake, and accumulation and physiological response of the plant in contaminated soil. Co-application of nZVI and PGPR had positive effects on plant establishment and growth in contaminated soil. Greater accumulation of Sb in the shoots compared to the roots of T. repens was observed in all treatments. Using nZVI significantly increased accumulation capacity of T. repens for Sb with the greatest accumulation capacity of 3896.4 μg per pot gained in the “PGPR+500 mg/kg nZVI” treatment. Adverse impacts of using 1000 mg/kg nZVI were found on plant growth and phytoremediation performance. Significant beneficial effect of integrated use of nZVI and PGPR on plant photosynthesis was detected. Co-application of nZVI and PGPR could reduce the required amounts of nZVI for successful phytoremediation of metalloid polluted soils. Intelligent uses of plants in accompany with nanomaterials and PGPR have great application prospects in removal of antimony from soil.
Показать больше [+] Меньше [-]Assessment of indoor air quality for a better preventive conservation of some French museums and monuments Полный текст
2020
Uring, Pauline | Chabas, Anne | Alfaro, Stéphane | Derbez, Mickaël
Indoor air quality in museums and historical buildings is of great concern for curators, since it can be a source of various alterations on artworks. In spite of their importance, very few studies study simultaneously the concentration of main gaseous pollutants, the composition of suspended (PM), and deposited (DPM) particulate matter. The aim of this article is to carry out a first environmental assessment in French museums or monuments. Three sites representative of contrasting environments (urban, marine, semi-rural) have been selected: the Cluny Museum (Paris), the Villa Kérylos (Beaulieu-sur-Mer), and the Château de Fontainebleau. The main results show that the input of terrigenous particles (calcite, clay) due to the surrounding restoration works dominates in Cluny; the external environment (O₃, RH, and marine particles) influences the interior atmosphere of the Villa Kérylos and the deliquescence of the deposited salts; against all expectations, anthropogenic particles (mascagnite and soot) are largely dominant in Fontainebleau. They are emitted in winter, when the warm, pulsating air gets dirty as it passes through the old heating ducts. This research shows the importance of particle mixtures in the environmental signature of the sites. These mixtures must be taken into account in order to reproduce indoor atmospheres in simulation chambers to achieve realistic artificial aging. This study also makes it possible to target the sources of pollution on which to act.
Показать больше [+] Меньше [-]Inorganic and organic characterization of Santa Lucía salt mine peloid for quality evaluations Полный текст
2020
Martínez-Villegas, Nadia | Suárez Muñoz, Margaret | González-Hernández, Patricia | Melián Rodríguez, Clara | Barrios Cossio, Josiel | Hernández Díaz, Rebeca | Fagundo Castillo, Juan R. | Gelen Rudnikas, Alina | Díaz López, Cristina | Pérez-Gramatges, Aurora | Díaz Rizo, Oscar
Santa Lucía peloid is a sediment used in pelotherapy in Cuban primary health care services. Therefore, in addition to physicochemical regulated parameters, other analyses are required to complement their physicochemical characterization and understand potential element mobility, radiological risk, and toxicity as well as likely bioactive compounds present in Santa Lucía peloid. For these purposes, inorganic and organic elements and compounds were considered to evaluate Santa Lucía peloid’s quality. This was accomplished through an integral approach that included (1) determination of physicochemical parameters (pH, electrical conductivity, oxidation–reduction potential, temperature, dissolved oxygen, elemental C, H, and N analyses, organic matter, and hexane removable substances content); (2) determination of total concentration of elements with biological and toxicological importance (i.e., Na, K, Ca, Mg, Fe, Mn, Cr, Cu, Ni, Pb, and Zn), as well as their distribution in operationally defined solid phases, mineralogy, particle size distribution, and total content of radionuclides and radiological dose calculations; and (3) its organic characterization. Results from this study showed that Santa Lucía peloid was non-contaminated and showed low metal mobility and acceptable radiological dose levels, being safe for therapeutic uses. Additionally, these results contribute to the understanding of the organic composition of peloides, provide strong evidences to scientifically explain the therapeutic action of peloids in the treatment of inflammatory diseases, and set a new frame to improve peloid guidelines in Cuba and other countries.
Показать больше [+] Меньше [-]Low-dose Roundup induces developmental toxicity in bovine preimplantation embryos in vitro Полный текст
2020
Cai, Wenyang | Yang, Xiao | Li, Xiangchen | Li, Hongtu | Wang, Shuo | Wu, Zhengchao | Yu, Mingxi | Ma, Shiliang | Tang, Shuang
Roundup is a widely used glyphosate-based herbicide worldwide. Roundup residues can be detected in the organs and urine of animals. However, its toxicity on mammalian preimplantation embryos has not been well investigated. Here, we show Roundup impairs the development and quality of bovine preimplantation embryos in a dose-dependent manner. Exposure to the agricultural recommended doses of Roundup caused in vitro developmental arrest and quick death of bovine embryos. Furthermore, even a very low concentration (0.9 ppm) of Roundup was harmful to bovine preimplantation development. In addition, Roundup increases intracellular calcium levels and induces oxidative stress and apoptosis in bovine embryos. Even if the embryos developed to morphologically normal blastocysts when cultured with low concentrations of Roundup, abnormal intracellular calcium and oxidative stress could be detected inside the embryos and led to an increased incidence of apoptosis in the blastocysts. These data suggest Roundup residues from the agricultural application are potentially dangerous to mammalian preimplantation embryos.
Показать больше [+] Меньше [-]The degradation of BPA on enhanced heterogeneous photo-Fenton system using EDDS and different nanosized hematite Полный текст
2020
Feng, Xiaoqing | Luo, Mengqi | Huang, Wenyu | Huang, Ying | Xie, Hongjie | Xu, Zisong | Zhang, Jian | Luo, Wei | Wang, Shuangfei | Lin, Hongfei
Photo-Fenton processes have been widely studied in wastewater treatment. In this research, the degradation of bisphenol A (BPA) was carried out in a new heterogeneous photo-Fenton process. The ethylenediamine-N,N′-disuccinic acid (EDDS) was used as chelating agent in this system with two different kinds of commercially available nanosized hematite (30 nm and 80 nm) addition. The results showed that the present of EDDS could enhance the degradation efficiency. And can be concluded that the degradation efficiency is better in the system with 30 nm hematite. The TEM, XRD, and specific surface area were conducted to understand the different characteristics of the two size hematite. The adsorption experiments of BPA and EDDS on hematite proved that there was little adsorption of BPA while the EDDS was adsorbed much more on hematite, which has confirmed Fe(III) and EDDS can form Fe(III)-EDDS complex. The effects of different parameters including hematite loading, H₂O₂, and EDDS concentrations on the degradation process were investigated. According to the results, the optimum condition for BPA degradation using 30 nm (0.8 g L⁻¹ hematite, 0.1 mmol L⁻¹ H₂O₂, and 1.2 mmol L⁻¹ EDDS) and 80 nm (0.6 g L⁻¹ hematite, 0.05 mmol L⁻¹ H₂O₂, and 1.2 mmol L⁻¹ EDDS) hematite were selected. It was confirmed that the ·OH plays an important role in the oxidation process through attacking the BPA molecule and produce hydroxyl addition derivative. In addition, O₂ can react with electron (e⁻) and holes (h⁺) produced by iron oxide under UV irradiation to create ¹O₂, which could work as potential reactive species to oxidize BPA.
Показать больше [+] Меньше [-]Polymorphism of glutathione S-transferase in the population of Polish patients with carcinoma of the prostate Полный текст
2020
Drozdz-Afelt, Joanna M. | Koim-Puchowska, Beata | Kłosowski, Grzegorz | Kamiński, Piotr
The aim of the study was frequency analysis of GSTM1, GSTT1, and GSTP1 polymorphisms of glutathione S-transferase in the group of patients with prostate cancer and in a control group of healthy individuals. Genomic DNA was isolated; molecular analysis of glutathione S-transferase M1 and T2 polymorphisms was performed using multiplex PCR and RFLP methods. The products of the PCR reaction were then visualized in agarose gel, and a statistical analysis of the results was performed. No statistically significant differences were found in the frequency of glutathione S-transferase polymorphisms between 66 patients with prostate cancer and the control group (64 healthy volunteers). The GSTM1 gene deletion was found in ca. 47% of patients with prostate cancer and in ca. 55% of the controls. The GSTT1 deletion was found in approximately 17% of patients and 14% of the controls. The distribution of GSTP1 Ile/Ile, Ile/Val, and Val/Val polymorphisms was ca. 51.5%, 39%, and 9% in the group of patients and 61%, 34%, and 5% in the control group, respectively. The results indicate that there is no relationship between glutathione S-transferase polymorphisms and prostate cancer in the study group, which is a novelty when compared with the previous work on the role of these genetic variants in the etiology of cancer.
Показать больше [+] Меньше [-]Microemulsion-mediated preparation of Ce2(MoO4)3 nanoparticles for photocatalytic degradation of crystal violet in aqueous solution Полный текст
2020
Dargahi, Maryam | Masteri-Farahani, Majid | Shahsavarifar, Samaneh | Feizi, Marzieh
Preparation of Ce₂(MoO₄)₃ nanoparticles is reported via the microemulsion method by using two different surfactants, i.e., cationic surfactant, cetyltrimethylammonium bromide (CTAB), and nonionic surfactant, Triton X-100. The water pools produced in the microemulsion systems behave as nanoreactors for reaction of the cerium (3+) and molybdate ions to produce Ce₂(MoO₄)₃ nanoparticles. The structure and morphology of the products were characterized by using Fourier-transform infrared (FT-IR) spectroscopy, energy-dispersive X-ray analysis (EDX), UV-Vis spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA-DTA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The prepared Ce₂(MoO₄)₃ nanoparticles were successfully utilized as photocatalysts to remove crystal violet from aqueous solution in which the maximum percentage of dye degradation was about 89% after 5 h under the visible light irradiation. Also, kinetic study of the photocatalytic degradation revealed that pseudo-second order model is the best one for describing kinetic of the reaction.
Показать больше [+] Меньше [-]Evaluation of bone marrow hemopoiesis and the elemental status of the red bone marrow of chickens under introduction of copper to the organism Полный текст
2020
Vishnyakov, Alexandr | Udavliev, Damir | Timofeev, Dmitriy | Kvan, Olga
The role of chemical elements in an organism is versatile and multifunctional. However, you should pay attention to the reaction of the organism on the introduction of chemical elements with different biological roles, which is predetermined by the physiological role of organs and body systems. These include the red bone marrow, which primarily responds to endogenous and exogenous factors by its functional significance. Analyzing the myelogram of birds after the various ways of copper NP introduction into the body and the different dosages, we found that, by the end of the experiment, the total numbers of bone marrow cells in all groups were lower than the initial values: in the second group—12.54% lower (p < 0.05), in third—26.32% lower (p < 0.001), for the fourth—14.75% lower (p < 0.05), with exception for the first experimental group where this index was 45.51% higher (р < 0.001). We revealed the following changes in the peripheral blood: the hemoglobin content by the end of the experiment was significantly higher than the initial values: by 18.63% for the first group (p < 0.01); 28.61% higher in the third group (p < 0.001); and 15.76% higher for the fourth (p < 0.01), except the animals of the second group (3.23% lower). The concentration of erythrocytes in all groups was higher than that of the background: by 24.56% (p < 0.001), by 3.37%, by 26.18% (p < 0.001), and by 14.85% (p < 0.01), respectively; the leukocyte concentration in the first group was 39.63% higher (p < 0.001), it remained at the level of the initial values in the other groups. The erythrocyte sedimentation rate in all groups increased by 2.4, 4.0, 2.01, and 1.86 times (p < 0.001), respectively. We revealed that the introduction of copper into an organism in the form of nanopowder both with feed and intramuscularly significantly caused an increase of the content of such elements as arsenic, copper, and silicon and a decrease of calcium, potassium, magnesium, phosphorus, boron, cobalt, iodine, lithium, sodium, zinc, tin, and strontium in the marrowy aspirate. Moreover, compared with the first group (p < 0.01), increasing doses of nanopowders caused a significant rise in the arsenic and tin concentrations and a decline of iodine and strontium. We found that copper nanoparticles ambiguously affect the bone marrow hemopoiesis of poultry; increasing the dose and changing the type of introduction activating the bone marrow hematopoietic function, in particular, granulocyto-, megakaryocyto-, and erythropoiesis.
Показать больше [+] Меньше [-]Spent mushroom substrate combined with alkaline amendment passivates cadmium and improves soil property Полный текст
2020
Jin, Zonghui | Zhang, Meng | Li, Rui | Zhang, Xu | Wang, Guoliang | Liu, Xuesheng | Qu, Juanjuan | Jin, Yu
As an extremely toxic metal, cadmium (Cd) is readily taken up by most plants. In situ Cd passivation is of great importance to reduce Cd availability in soil. In this experiment, two alkaline amendments, lime (L) (at a dosage of 0.02%, 0.04%, or 0.08%) and biochar (B) (at a dosage of 0.5%, 1%, or 2%), were used to improve Cd passivation by spent mushroom substrate (SMS) in a simulating Cd-contaminated soil (0.6 mg kg⁻¹). Results showed that the application of SMS alone reduced Cd bioavailability by 44.80% and EC by 9.71% and increased soil pH by 0.61 units, CEC by 25.32%, and soil enzymes activities by 17.11% to 21.10% compared with non-amendment Cd-contaminated soil. Biochar combination enhanced the efficiency of SMS on Cd reduction by 48.32–66.58% and pH increased by 0.17 to 0.59 units and enzymes activities elevation by 5.74% to 47.29% in a dose-dependent manner. Lime also facilitated SMS to passivate Cd by decreasing bioavailable Cd by 63.10%–66.47% and increasing soil pH by 0.25–0.72 units and enzymes activities by 3.28% to 37.86% compared to those of SMS. Among six combined amendments, SMSB3 (0.5% SMS + 2% B) performed best in reducing bioavailable Cd (39.46% higher than SMS), increasing organic matter content (28.54% higher than SMS) and soil enzyme activities (25.82%, 47.29%, and 26.23% higher than that of SMS for catalase, urease, and invertase, respectively). Both biochar and lime can assist SMS to passivate Cd and improve soil property, and biochar is more efficient than lime in reducing cadmium content and increasing enzyme activity and organic matter.
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