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Screening of protozoan and microsporidian parasites in feces of great cormorant (Phalacrocorax carbo) 全文
2017
Rzymski, Piotr | Słodkowicz-Kowalska, Anna | Klimaszyk, Piotr | Solarczyk, Piotr | Poniedziałek, Barbara
The global population of great cormorants (Phalacrocorax carbo L.) is on the rise. These birds, characterized by rapid metabolism, can deposit large quantities of feces, and because they breed on the land but forage on water, both terrestrial and aquatic environments can be simultaneously affected by their activities. The contribution of great cormorants in the dispersal of bacterial and viral pathogens has been immensely studied; whereas, the occurrence of eukaryotic parasites such as protozoans and microsporidians in these birds is little known. The present study investigated the presence of dispersive stages of potentially zoonotic protozoans belonging to the genera Blastocystis, Giardia and Cryptosporidium, and Microsporidia spores in feces collected from birds inhabiting the breeding colony established at one lake island in Poland, Europe. The feces were examined by coprological techniques (staining with iron hematoxylin, Ziehl-Neelsen, and modified Weber’s chromotrope 2R–based trichrome), and with immunofluorescence antibody MERIFLUOR Cryptosporidium/Giardia assay. As found, the Cryptosporidium oocysts were identified rarely in 8% of samples (2/25; 3–5 × 10³/g) and no cysts of Giardia and Blastocystis were detected. Microsporidian spores were detected in 4% of samples (1/25) but at very high frequency (4.3 × 10⁴/g). No dispersive stages of parasites were identified in water samples collected from the littoral area near the colony. Despite the profuse defecation of cormorants, their role in the dispersion of the investigated parasites may not be as high as hypothesized.
显示更多 [+] 显示较少 [-]A powerful tool for assessing distribution and fate of potentially toxic metals (PTMs) in soils: integration of laser ablation spectrometry (LA-ICP-MS) on thin sections with soil micromorphology and geochemistry 全文
2017
Scarciglia, Fabio | Barca, Donatella
The dynamic behavior and inherent spatial heterogeneity, at different hierarchic levels, of the soil system often make the spatial distribution of potentially toxic metals (PTMs) quite complex and difficult to assess correctly. This work demonstrates that the application of laser ablation spectrometry (LA-ICP-MS) to soil thin sections constitutes an ancillary powerful tool to well-established analytical methods for tracing the behavior and fate of potential soil contaminants at the microsite level. It allowed to discriminate the contribution of PTMs in distinct soil sub-components, such as parent rock fragments, neoformed, clay-enriched or humified matrix, and specific pedogenetic features of illuvial origin (unstained or iron-stained clay coatings) even at very low contents. PTMs were analyzed in three soil profiles located in the Muravera area (Sardinia, Italy), where several, now abandoned mines were exploited. Recurrent trends of increase of many PTMs from rock to pedogenic matrix and to illuvial clay coatings, traced by LA-ICP-MS compositional data, revealed a pedogenetic control on metal fractionation and distribution, based on adsorption properties of clay minerals, iron oxyhydroxides or organic matter, and downprofile illuviation processes. The main PTMs patterns coupled with SEM-EDS analyses suggest that heavy metal-bearing mineral grains were sourced from the mine plants, in addition to the natural sedimentary input. The interplay between soil-forming processes and geomorphic dynamics significantly contributed to the PTMs spatial distribution detected in the different pedogenetic horizons and soil features.
显示更多 [+] 显示较少 [-]Effect of Si-rich substances on phosphorous adsorption by sandy soils 全文
2017
Matichenkov, Vladimir V. | Bocharnikova, Elena A. | Pakhnenko, Ekaterina P. | Khomiakov, Dmitry M.
The poor adsorption capacity of sandy soils is one of the primary reasons of a high level of phosphorus (P) leaching. Silicon (Si)-rich soil amendments have the potential to improve the low absorption capacity of sandy soils for P. The objective of this study was to evaluate the ability of different Si-rich materials to regulate P adsorption and retention by sandy soils. Amorphous fine silica (FSS), calcium silicate (CaSiO₃), chemically pure CaCO₃, and two types of Ca-silicate slags from metal industry (Pro-Sil) and chemical industry (TS) were used in laboratory experiments being conducted with pure quartz sand and cultivated and virgin Entisols and Spodosols collected in the South Florida. The binding energy-related constants were evaluated for soils treated by Si-rich materials and then incubated during 2 months. The following row of tested materials on the increasing level of “affinity parameter” was determined: for virgin Spodosol, Pro-Sil < CaCO₃ < FSS< CaSiO₃ < TS; for cultivated Spodosol, FSS < Pro-Sil < CaCO₃< CaSiO₃ < TS; for virgin Entisol, Pro-Sil < CaSiO₃ < CaCO₃ < FSS < TS; and for cultivated Entisol, FSS < Pro-Sil < CaSiO₃ < CaCO₃ < TS. Chemical, physical, and physical-chemical mechanisms of increasing soil adsorption capacity are hypothesized and discussed to explain the results obtained. The conducted experiments have demonstrated high prospective of Si-rich materials for reduction of P leaching from cultivated sandy soils.
显示更多 [+] 显示较少 [-]Tributyltin chloride disrupts aortic vascular reactivity and increases reactive oxygen species production in female rats 全文
2017
Ximenes, Carolina Falcão | Rodrigues, Samya Mere Lima | Podratz, Priscila Lang | Merlo Juárez, Eduardo | de Araújo, Julia Fernandez Puñal | Rodrigues, Lívia Carla Melo | Coitinho, Juliana Barbosa | Vassallo, Dalton Valentim | Graceli, Jones Bernardes | Stefanon, Ivanita
Organotin compounds, such as tributyltin (TBT), are environment contaminants that induce bioaccumulation and have potential toxic effects on marine species and mammals. TBT have been banned by the International Maritime Organization in 2003. However, the assessment of butyltin and metal contents in marine sediments has demonstrated high residual levels of TBT in some cases exceeding 7000 ng Sn g⁻¹. The acceptable daily intake (ADI) level for TBT established by the World Health Organization is 0.5 μg/kg bw/day is based on genotoxicity, reproduction, teratogenicity, immunotoxicity, and mainly neurotoxicity. However, their effect on the cardiovascular system is not well understood. In this study, female rats were exposed to 0.5 μg/kg/day of TBT for 15 days with the goal of understanding the effect of TBT on vascular function. Female Wistar rats were treated daily by gavage and divided into control (n = 10) and TBT (n = 10) groups. The aortic rings were incubated with phenylephrine in both the presence and absence of endothelium. The phenylephrine concentration–response curves were generated by exposing endothelium-intact samples to Nᴳ-nitro-L-arginine methyl ester (L-NAME), apocynin, superoxide dismutase (SOD), catalase, tiron, and allopurinol. Acetylcholine (ACh) and sodium nitroprusside (SNP) were used to evaluate the relaxation response. Exposure to TBT reduced serum 17β-estradiol E₂ levels and increased vascular reactivity. After incubation with L-NAME, the vascular reactivity to phenylephrine was significantly higher. Apocynin, SOD, catalase, and tiron decreased the vascular reactivity to phenylephrine to a significantly greater extent in TBT-treated rats than in the control rat. The relaxation induced by ACh and SNP was significantly reduced in TBT rats. Exposure to TBT induced aortic wall atrophy and increased superoxide anion production and collagen deposition. These results provide evidence that exposing rats to the current ADI for TBT (0.5 μg/kg) for 15 days induced vascular dysfunction due to oxidative stress and morphological damage and should be considered an important cardiovascular risk factor.
显示更多 [+] 显示较少 [-]Plant-microbial association in petroleum and gas exploration sites in the state of Assam, north-east India—significance for bioremediation 全文
2017
Sarma, Hemen | Islam, N. F. | Prasad, M. N. V.
The state of Assam in north-east India gained popularity in Asia because of discovery of oil. Pollution due to petroleum and gas exploration is a serious problem in Assam. Oil and gas exploration by various agencies in Assam resulted in soil pollution due to hydrocarbons (HCs) and heavy metals (HMs). Bioremediation gained considerable significance in addressing petroleum hydrocarbon polluted sites in various parts of the world. In this investigation, we have observed 15 species of plants belonging to grass growing on the contaminated soils. Among 15 species of grasses, 10 species with high important value index (IVI) were found to be better adapted. The highest IVI is exhibited by Axonopus compressus (21.41), and this grass can be identified as key ecological tool in the rehabilitation of the degraded site. But no definite correlation between the IVI and the biomass of the various grass existed in the study sites. Chemical study of rhizosphere (RS) and non-rhizosphere (NRS) soil of these grasses revealed both aromatic and aliphatic compounds (M.W. 178–456). Four-ring pyrene was detected in NRS soil but not in RS soil. Microbiological study of RS and NRS soil showed high colony-forming unit (CFU) of HC-degrading microbes in RS compared to NRS. The increased microbial catabolism in RS soil established the fact that pyrene is transformed to aliphatic compounds. Metals in RS soil ranged from (in mg kg⁻¹) 222.6 to 267.3 (Cr), 854 to 956 (Pb) and 180 to 247 (Ni), but despite the very high total metal concentration in RS and NRS soil, the CaCl₂-extracted metals were relatively low in RS soil (1.04 for Cr, 0.56 for Pb, 0.35 for Ni). Plants with the highest uptake of metals were Leersia hexandra (36.43 mg Cr kg⁻¹) and Kyllinga brevifolia (67.73 mg Pb kg⁻¹ and 40.24 mg Ni kg⁻¹). These plant species could be potentially exploited for biomonitoring and bioremediation. Out of 15 plant species, 8 of them have high percentages of cellulose, crude fibres, lignin and holocellulose (14–16%). The explored species thus qualify as energy crops since they have high bioproductivity and are more resilient and adaptable in HM/HC-contaminated sites.
显示更多 [+] 显示较少 [-]High efficiency removal of triclosan by structure-directing agent modified mesoporous MIL-53(Al) 全文
2017
Dou, Rongni | Zhang, Junya | Chen, Yuancai | Feng, Siyuan
In order to expand the potential applications of metal-organic frameworks (MOFs), structure directing agents modified mesoporous MIL-53(Al) (MIL-53(Al)-1) was investigated to adsorb triclosan (TCS) with two different initial concentrations. MIL-53(Al)-1 with high mesoporosity and total pore volume exhibited higher adsorption capacity and 4.4 times faster adsorption of TCS at low concentration (1 mg L⁻¹) than that of microporous MIL-53(Al). Also, mesoporous as well as microporous MIL-53(Al) showed significant higher adsorption capacity and two orders of magnitude greater fast uptake of TCS than two kinds of mesoporous-activated carbon. The adsorption of TCS onto MIL-53(Al)-1 released more energy and had higher disorderliness than TCS on MIL-53(Al). The superior adsorption characteristics of MIL-53(Al)-1 were preserved over a wide pH range (4–9), at high concentration of ionic strengths, and in the presence of coexisting compounds (anions, cations, phenol, aniline, and humic acid). The selectivity adsorption and Fourier transform infrared (FT-IR) spectra revealed that TCS adsorption on MIL-53(Al)s was mainly driven by hydrophobicity interaction assisted with hydrogen bonding on MIL-53(Al)s. MIL-53(Al)s can be effectively regenerated several times by washing with 90% methanol-water (pH 11). All of the above results demonstrated MIL-53(Al)s are promising adsorbents for water purification. Graphical abstract
显示更多 [+] 显示较少 [-]Impact of Moringa oleifera seed aqueous extract on some biological, biochemical, and histological aspects of Biomphalaria alexandrina snails 全文
2017
Ibrahim, Amina M. | Abdalla, Aboelfetoh M.
Schistosomiasis is one of the neglected tropical diseases. It is a snail-borne trematode infection, and Biomphalaria alexandrina snails are the intermediate host of Schistosoma mansoni in Egypt. The objective of this study is to evaluate the molluscicidal activity of the aqueous seed extract of Moringa oleifera against B. alexandrina snails. The results showed that this aqueous extract was lethal for B. alexandrina snails (LC₅₀ 0.27 g/l; LC₉₀ 0.41 g/l). Exposure of snails to the sublethal concentrations of this aqueous extract caused a considerable reduction in survival rates and hatchability rates of eggs of these snails. Moreover, it negatively affected some biochemical aspects, where it increased the levels of transaminases (ALT and AST), while it decreased the concentrations of total protein, albumin, and globulin concentration. Histological examinations of the digestive gland of snails exposed to the sublethal concentrations of aqueous seed extract of M. oleifera revealed severe damage in the digestive cells, where they lost their tips and some were degenerated, while the secretory cells increased in number. Regarding the hermaphrodite gland, there were losses of connective tissues and irregular sperms, and the eggs were degenerated. These findings prove the potent activity of aqueous seed extract of M. oleifera against the intermediate hosts of Schistosoma mansoni and provide a considerable scope in exploiting local indigenous resources for snails’ molluscicidal agents.
显示更多 [+] 显示较少 [-]Contamination from organochlorine pesticides (OCPs) in agricultural soils of Kuttanad agroecosystem in India and related potential health risk 全文
2017
Sruthi, S. N. | Shyleshchandran, M. S. | Mathew, Sunil Paul | Ramasami, E.
The presence and distribution of a few organochlorine pesticides (OCPs) in the paddy fields of the Kuttanad agroecosystem (KAE) was examined in the present study. Kuttanad forms a part of the Vembanad wetland system which is a Ramsar site of international importance in the state of Kerala. This study, to the best of our knowledge, is the first report on the occurrence of OCP residues in KAE. Pesticide residue analysis was done with gas chromatograph (GC-ECD). Twenty-one soil samples were collected for the multiresidual analysis of OCPs. Sixteen OCP residues with a notable concentration were observed from the study area. α-BHC; β-BHC; γ-BHC; δ-BHC; α-chlordane; γ-chlordane; heptachlor; 4,4-DDT; 4,4-DDE; 4,4-DDD; α-endosulfan; β-endosulfan; aldrin; dieldrin; endrin aldehyde; and endrin ketone were the residues observed. The percentage-wise occurrence of OCP residues in the soil samples analysed (total of 63 samples from 21 sites, three samples per site) exhibits the following order: Σ BHC˃ Σ chlordane ˃ Σ dieldrin ˃ Σ aldrin ˃ Σ endrin˃ Σ heptachlor = endosulfan˃ Σ DDT. All pesticides detected from KAE are in the list of priority pollutants of US Environmental Protection Agency (USEPA). The distribution pattern of OCPs in the KAE soils revealed their origin as both historical and recent application of pesticides. Health risk assessment of OCP residues on human population was also conducted. The findings indicated that the concentrations of OCPs were within the permissible limits of USEPA, thus, the human population in the study area was safe.
显示更多 [+] 显示较少 [-]Protective effect of Nigella sativa seeds against spermatocyte chromosomal aberrations and genotoxicity induced by carbon tetrachloride in mice 全文
2017
Abdel-Moneim, Ashraf M. | Essawy, Amina E. | Hamed, Sherifa S. | Abou-Gabal, Ashgan A. | Alzergy, Aglal A.
Nigella sativa is a well-known dietary antioxidant and a valuable inhibitor of clastogenesis and carcinogenesis. The purpose of the present work was to investigate the effects of N. sativa seeds against chromosomal aberrations in primary spermatocytes and early embryonic lethality induced by CCl₄ hepatotoxin in Swiss albino mice. One hundred male Swiss albino mice were randomly divided into five groups. Groups I, II, and III received only normal saline, olive oil, and aqueous suspension of N. sativa seeds (50 mg/kg b.w.), while groups IV and V were orally given CCl₄ dissolved in olive oil at a dose level of 1.9 (¼ LD₅₀) alone and with aqueous suspension of N. sativa seeds (50 mg/kg b.w.) alternately. Aqueous extract of N. sativa significantly reduced the elevated frequency of chromosomal aberrations induced by CCl₄ in mouse primary spermatocytes. For the male-dominant lethal test, four males from each group (control and experimental) were used and each male was mated for 13 days to two untreated virgin females. On days 14–16 after breeding, all the females were evaluated for incidence of pregnancy, live implants, and fetal deaths. Treatment with 1/4 LD₅₀ of CCl₄ induced positive dominant lethal mutation, reflecting a high rate of deformations in male germ cells. Interestingly, no dominant lethal mutations were recorded in females mated to male mice treated with CCl₄ plus N. sativa. Under the experimental conditions of this study, our results highlight the beneficial role of N. sativa against CCl₄-induced mutagenicity.
显示更多 [+] 显示较少 [-]Methanol-enhanced removal and metabolic conversion of formaldehyde by a black soybean from formaldehyde solutions 全文
2017
Tan, Hao | Xiong, Yun | Li, Kun-zhi | Chen, Li-Mei
Methanol regulation of some biochemical and physiological characteristics in plants has been documented in several references. This study showed that the pretreatment of methanol with an appropriate concentration could stimulate the HCHO uptake by black soybean (BS) plants. The process of methanol-stimulated HCHO uptake by BS plants was optimized using the Central Composite Design and response surface methodology for the three variables, methanol concentration, HCHO concentration, and treatment time. Under optimized conditions, the best stimulation effect of methanol on HCHO uptake was obtained. ¹³C-NMR analysis indicated that the H¹³CHO metabolism produced H¹³COOH, [2-¹³C]Gly, and [3-¹³C]Ser in BS plant roots. Methanol pretreatment enhanced the metabolic conversion of H¹³CHO in BS plant roots, which consequently increased HCHO uptake by BS plants. Therefore, methanol pretreatment might be used to increase HCHO uptake by plants in the phytoremediation of HCHO-polluted solutions.
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