خيارات البحث
النتائج 4821 - 4830 من 6,560
Residue dissipation, evaluation of processing factor and safety assessment of hexythiazox and bifenazate residues during drying of grape to raisin النص الكامل
2020
Thekkumpurath, Ahammed Shabeer | Girame, Rushali | Hingmire, Sandip | Jadhav, Manjusha | Jain, Prachi
An analytical method for the simultaneous analysis of hexythiazox and bifenazate residues in grape and raisin was validated by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The extraction method involved liquid-liquid extraction with ethyl acetate and dSPE cleanup with primary secondary amine (PSA). The drying of grape to raisin may increase or decrease residues of pesticides. During the raisin making process, the dissipation of residue was evaluated and the processing factor (PF) was established for drying. Dissipation data were best fitted to 1ˢᵗ + 1ˢᵗ-order kinetics with a half-life ranging between 6–10 days for hexythiazox and 5–6 days for bifenazate. The PF value for overall raisin making was found to be 0.20–0.36 for hexythiazox and 0.14–0.15 for bifenazate indicating degradation of the residues. However, the PF value varies between 1.13–1.64 for hexythiazox and 0.94–1.12 for bifenazate during the drying process indicating concentration of the residues in drying. The dietary exposure on each sampling day was less than the respective maximum permissible intake (MPI). The residues in market samples of raisins were devoid of any risk of acute toxicity related to dietary exposure. The PF value generated will be useful for the field level management of residues in grape intended for raisin preparation.
اظهر المزيد [+] اقل [-]A cohort study of banana plantation workers in the French West Indies: first mortality analysis (2000–2015) النص الكامل
2020
Luce, Danièle | Dugas, Julien | Vaidie, Amandine | Michineau, Léah | El-Yamani, Mounia | Multigner, Luc
Chlordecone, an organochlorine insecticide, was widely used in the French West Indies banana plantations. We set up a cohort of banana plantation workers who worked between 1973 and 1993, the period of authorized use of chlordecone. Vital status and causes of death were collected from French national registries. Workers were followed up from 1 January 2000 to 31 December 2015. Cause-specific mortality in the cohort was compared to that of the general population of the French West Indies by computing standardized mortality ratios (SMRs). A total of 11,112 workers (149,526 person-years, 77% men) were included in the mortality analysis, and 3647 deaths occurred over the study period. There was a slight deficit in all-cause mortality, which was statistically significant in men (SMR = 0.93, 95% CI 0.89–0.96), but not in women (SMR = 0.96, 95% CI 0.89–1.04). All-cancer mortality did not differ significantly from that of the general population (men: SMR = 0.96, 95% CI 0.90–1.03; women: SMR = 1.04, 95% CI 0.89–1.21). Significant excesses of deaths were observed for stomach cancer in women (SMR = 1.94, 95% CI 1.24–2.89) and pancreatic cancer in women farm owners (SMR = 2.31, 95% CI 1.06–4.39). Mortality from prostate cancer was similar to that of the general population in the whole cohort (SMR = 1.00; 95% CI 0.89–1.13) and non-significantly elevated among farm workers (SMR = 1.10, 95% CI 0.87–1.36). Non-significant increases in mortality were also observed for lung cancer in women, leukemia in men, and non-Hodgkin lymphoma in both genders.
اظهر المزيد [+] اقل [-]Senna alexandrina extract supplementation reverses hepatic oxidative, inflammatory, and apoptotic effects of cadmium chloride administration in rats النص الكامل
2020
Wang, Xianbin | Wang, Ting | Pan, Tingting | Huang, Mei | Ren, Weihua | Xu, Geliang | Amin, Hatem K. | Kassab, Rami B. | Abdel Moneim, Ahmed E.
Senna alexandrina is traditionally used for its antioxidant and anti-inflammatory properties, but little information is available concerning its potential protective effects against cadmium, which is a widespread environmental toxicant that causes hepatotoxicity. Here, we explored the effects of S. alexandrina extract (SAE) on cadmium chloride (CdCl₂)-induced liver toxicity over 4 weeks in rats. Rats were allocated into four groups: control, SAE (100 mg/kg), CdCl₂ (0.6 mg/kg), and SAE + CdCl₂, respectively. Cadmium level in hepatic tissue, blood transaminases, and total bilirubin as indicators of liver function were assessed. Oxidative stress indices [malondialdehyde (MDA), nitrate/nitrite (NO), and glutathione (GSH)], antioxidant molecules [superoxide dismutase (SOD, catalase (CAT), glutathione-derived enzymes, and nuclear factor erythroid 2-related factor 2 (Nrf2)], pro-inflammatory mediators [interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α)], apoptosis proteins (Bcl-2, Bax, and caspase-3), and histological alterations to the liver were examined. SAE administration before CdCl₂ exposure decreased cadmium deposition in liver tissue and the blood liver function indicators. SAE pre-treatment prevented oxidative, inflammatory, and apoptotic reactions and decreased histological alterations to the liver caused by CdCl₂ exposure. SAE can be used as a promising protective agent against CdCl₂-induced hepatotoxicity by increasing Nrf2 expression. Graphical abstract
اظهر المزيد [+] اقل [-]Selenite removal from wastewater using fungal pelleted airlift bioreactor النص الكامل
2020
Negi, Bharat Bhushan | Sinharoy, Arindam | Pakshirajan, Kannan
This study investigated the removal of selenite from wastewater using the fungus Asergillus niger KP isolated from a laboratory scale inverse fluidized bed bioreactor. The effect of different carbon sources and initial selenite concentration on fungal growth, pellet formation and selenite removal was first examined in a batch system. The fungal strain showed a maximum selenite removal efficiency of 86% in the batch system. Analysis of the fungal pellets by field-emission scanning electron microscopy, field-emission transmission electron microscopy and energy-dispersive X-ray spectroscopy revealed the formation of spherical-shaped elemental selenium nanoparticles of size 65–100 nm. An increase in the initial selenite concentration in the media resulted in compact pellets with smooth hyphae structure, whereas the fungal pellets contained hair like hyphae structure when grown in the absence of selenite. Besides, a high initial selenite concentration reduced biomass growth and selenite removal from solution. Using an airlift reactor with fungal pellets, operated under continuous mode, a maximum selenite removal of 94.3% was achieved at 10 mg L⁻¹ of influent selenite concentration and 72 h HRT (hydraulic retention time). Overall, this study demonstrated very good potential of the fungal-pelleted airlift bioreactor system for removal of selenite from wastewater. Graphical abstract
اظهر المزيد [+] اقل [-]Remediation of carcinogenic arsenic by pyroaurite-based green adsorbent: isotherm, kinetic, mechanistic study, and applicability in real-life groundwater النص الكامل
2020
Yadav, Manoj Kumar | Gupta, Ashok Kumar | Ghosal, Partha Sarathi | Mukherjee, Abhijit
The removal of the harmful carcinogen arsenic from drinking water by a green technology is a major concern in the field of environmental engineering. The sorptive profile of arsenic remediation by calcined Mg-Fe-layered double hydroxide, fabricated by a one-pot synthesis technique, was investigated to delineate its applicability in real-life water. The physicochemical properties of adsorbent, as demonstrated from spectroscopy and microscopy, which described the existence of amorphous material with significant surface roughness possess selectivity towards arsenic. The isotherm and kinetic along with thermodynamic modeling exhibited the occurrence of spontaneous (ΔG⁰ value = − 8.084 kJ/mol to − 10.942 kJ/mol), endothermic (ΔH⁰ value = 12.135 kJ/mol), and physisorption reactions (Eₐd = 4.103–5.832 kJ/mol, Eₐ = 11.546 kJ/mol, S* = 0.0005 << 1, and ΔHₓ = 9.23–16.29 kJ/mol) with high uptake rate and adsorption potential of adsorbent. The isotherm and kinetics were demonstrated by Temkin (R² = 0.944–0.969) and Elovich (R² = 0.996–0.998) models, respectively, with high statistical significance. The intraparticle diffusion model which established the rate-limiting step is the combination of both film and pore diffusions. The applicability of layered double hydroxide (LDH) material in the real-life water was confirmed by isotherm and kinetic modeling along with the regeneration/reuse potential. The adsorptive removal of arsenic by the LDH material exhibited to be a promising technique without creating any secondary hazard.
اظهر المزيد [+] اقل [-]Tribulus terrestris ameliorates carbon tetrachloride-induced hepatotoxicity in male rats through suppression of oxidative stress and inflammation النص الكامل
2020
Kilany, Omnia E. | El-Beltagy, Marwa A. | El-Sherbeeny, Nagla A.
Hepatoprotection is a goal for the harmful effect of several hepatotoxic agents. The present study has been executed to assess the useful impacts of Tribulus terrestris (TT) and silymarin (SLM) against carbon tetrachloride (CCL₄)-induced hepatotoxicity. Forty-two male rats were partitioned into six groups: group I: received 0.3% CMC-Na in distilled water, group II: TT (500 mg/kg BW, orally), group III: SLM (200 mg/kg, orally) for 14 consecutive days (on days 11 and 12 intraperitoneal corn oil), group IV: CCL₄, group V: TT (500 mg/kg BW) plus CCL₄, and group VI: SLM (200 mg/kg orally) plus CCL₄. The CCL₄ was administered (2.0 ml/kg BW) intraperitoneal on days 11 and 12. Sera were collected for assessment of hepatic injury markers and pro-inflammatory cytokines. Additionally, liver tissue oxidative stress, lipid peroxidation, histopathological examination, and immunohistochemical analysis (Bax and bcl-2) were done. CCL₄ injection induced significant reductions in hepatic antioxidants while increased hepatic lipid peroxidation as well as serum hepatic injury biomarkers and pro-inflammatory cytokines. The histopathological examination showed necrotic and degenerative changes in the hepatic tissue, while immunohistochemical analysis revealed marked hepatic expression of activated Bax, and bcl-2, following CCL₄ injection. TT pretreatment significantly improved all examined parameters and restored the hepatic architecture. The current study illustrated that TT effectively alleviates hepatic oxidative damage, apoptosis, and inflammation, induced by acute CCL₄ intoxication. In this manner, TT has promising cytoprotective powers against hepatotoxicity induced by CCL₄.
اظهر المزيد [+] اقل [-]Marine macroalgae as food for earthworms: growth and selection experiments across ecotypes النص الكامل
2020
Butt, Kevin Richard | Méline, Camille | Pérès, Guénola
Marine macroalgae as food for earthworms: growth and selection experiments across ecotypes النص الكامل
2020
Butt, Kevin Richard | Méline, Camille | Pérès, Guénola
Historically, subsistence farmers around the Atlantic coast of NW Europe utilized marine algae as a fertilizer in agroecosystems, a practice that continued in small areas and is now considered to have real potential for re-establishing sustainable food production systems on marginal soils. Earthworms form a significant component of soil fauna, and their ecosystem services are well-documented. Therefore, palatability of marine organic amendments to faunal detritivores of terrestrial systems is of interest. This work aimed to assess the potential for growth of Aporrectodea caliginosa, Lumbricus rubellus and Aporrectodea longa fed with two common macroalgae (seaweeds), Laminaria digitata and Fucus serratus. In addition, choice chambers were constructed to permit earthworm selection of these macroalgae with more conventional organic materials, horse manure (HM) and birch leaves (BL). Over a period of 2 months, earthworm species showed significantly greater mass gain with conventional food (p < 0.05). Laminaria outperformed Fucus, which in turn was superior to soil alone. Similarly, when given a choice, a significant preference (p < 0.001) was shown for the more nitrogen-rich HM and BL over the seaweeds. No removal was recorded for A. caliginosa when offered seaweeds only. By contrast, L. rubellus and A. longa showed significant preferences (p < 0.001) for Laminaria over Fucus and fresh material over degraded. These results underline an interest to profit from natural resources (seaweeds) to maintain or improve soil biological quality in marginal coastal areas.
اظهر المزيد [+] اقل [-]Marine macroalgae as food for earthworms: growth and selection experiments across ecotypes النص الكامل
2020
Butt, Kevin Richard | Méline, Camille | Pérès, Guénola | University of Central Lancashire [Preston] (UCLAN) | Sol Agro et hydrosystème Spatialisation (SAS) ; Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-INSTITUT AGRO Agrocampus Ouest ; Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
International audience
اظهر المزيد [+] اقل [-]Performance evaluation of conventional and hybrid woven fabrics for the development of sustainable personal protective clothing النص الكامل
2020
Memon, Arshad Hussain | Peerzada, Mazhar Hussain | Brohi, Khan Muhammad | Memon, Sheeraz Ahmed | Mangi, Sajjad Ali
This study examines the performance level of hybrid woven protective clothing (HWPC), manufactured from Kevlar® (K) and Ramie (R) yarns. The weave structures (plain, twill 1/3) and variables fiber ratios were used to produce HWPC. The performance level of HWPC was measured according to EN 388:2016. We came to the conclusion that blade cut resistance of plain and twill structure sustained protection level up to increase of KR 80:20 and KR 70:30, respectively; puncture resistance of K100% and HWPC remained in the same level of protection for plain and twill weaves; Abrasion resistance of K100% and HWPC of plain and twill weaves samples presented abrasive performance of same protection level, but the average number of cycles sustained for twill weave samples was slightly higher than plain weave. However, comparing the plain and twill weaves sample for tear resistance, twill weave samples have higher tear resistance than plain weave. A gray relational analysis and Taguchi method was performed to optimize the performance of two structures with variable fiber ratios. It was established that the article produced with K&R yarns with KR 80:20 ratio and twill weave presented the best performance against all test runs. The main objective of this study is to reduce plastic pollution by reducing the amount of synthetic fiber proportion in personal protective clothing and thereby reducing the dependence on nonrenewable sources for synthetic fiber. The 41 g/m² reduction of Kevlar® fiber has been made in a conventional PC with ramie fiber, without compromising the protection level. This will enhance the sustainability of HWPC.
اظهر المزيد [+] اقل [-]Assessment of phytostabilization potential of two Salix L. clones based on the effects of heavy metals on the root anatomical traits النص الكامل
2020
Hrkić Ilić, Zorana | Pajević, Slobodanka | Borišev, Milan | Luković, Jadranka
Willow species (Salix L.) are a useful tool for assessing phytostabilization of the sites polluted by heavy metals. Phytostabilization potential of two willow genotypes (Salix alba L. clone ‘68/53/1’ and Salix nigra Marshall clone ‘0408’) has been evaluated in a 45-day hydroponic experiment, using stem cuttings (diameter 12 to 14 mm, length 20 cm) exposed to two concentrations (10⁻⁴ M and 10⁻⁵ M) of individually applied Cd, Ni, and Pb. Metals were diluted in 25% Hoagland’s solution, in forms of CdCl₂·H₂O, NiSO₄·6H₂O, and Pb-EDTA. The control group of cuttings was grown in 25% Hoagland’s solution without heavy metals. High Cd concentrations in willow roots, 8637 mg/kg (clone ‘68/53/1’) and 6728 mg/kg of dry weight (clone ‘0408’), have indicated a high phytostabilization potential. However, detailed analyses of cross-sectional area of the root cortex and the central cylinder revealed that the excess concentration of Cd led to a significant reduction of measured anatomical rootʼs traits of clone ‘68/53/1’ in comparison with the control samples. Excessive concentration of Ni and Pb in nutrient solution increased the values of quantitatively measured rootʼs traits of clone ‘0408’, implying stimulatory effects of the applied concentrations. Concentration of 10⁻⁴ M of each metal had more negative effects on the rootsʼ anatomical traits, notably on parenchymal and exodermal cells and vessels. Deposits of metals were observed in root tissues. Clone ‘0408’ demonstrated an increased tolerance to heavy metals, which could potentially make this clone useful in phytostabilization.
اظهر المزيد [+] اقل [-]Copper removal from wastewater by a chitosan-based biodegradable composite النص الكامل
2020
Velasco-Garduño, Oscar | Martinez, Manuel E. | Gimeno, Miquel | Tecante, Alberto | Beristain-Cardoso, Ricardo | Shirai, Keiko
This work demonstrates that a biodegradable chitosan-based biocomposite packed in mini-reactors successfully removes copper ions from aqueous solutions. The chitosan is obtained by deacetylation of biological chitin, which is extracted from shrimp wastes by lactic acid fermentation. The polysaccharide is embedded in a biodegradable prepolymer matrix before extrusion to produce porous cylindrical pellets of 2 × 80 mm. The highest copper ion removal is 62.5 mg Cu²⁺ per g of the biodegradable adsorbent. Additionally, the adsorption capacity of the material, below its saturation, allows several cycles of reuse with a hydraulic retention time reduction of 1 h. This chitosan-based material is advantageous when compared with other approaches using non-biodegradable materials or costly commercial adsorbents for removing heavy metal ions in wastewater effluents as well as a filter component in water purification devices.
اظهر المزيد [+] اقل [-]