Affiner votre recherche
Résultats 5741-5750 de 6,497
Effect of supra-nutritional selenium-enriched probiotics on hematobiochemical, hormonal, and Doppler hemodynamic changes in male goats Texte intégral
2020
Mandour, Ahmed S. | Samir, Haney | El-Beltagy, Marwa A. | Abdel-Daim, Mohamed M. | Izumi, Watanabe | Ma, Danfu | Matsuura, Katsuhiro | Tanaka, Ryou | Watanabe, Gen
In this study, the influence of supra-nutritional organic selenium (Se) supplement on hematology and plasma biochemicals, including antioxidant parameters and plasma reproductive hormones, as well as blood flow characteristics in the supratesticular and common carotid arteries (STA and CCA, respectively) were investigated. For this purpose, 15 male goats were used and classified into three equal groups according to the supplementation of the basal diet (BD): negative control (NC), probiotic (Pro), and Se-probiotic (Se-Pro) groups. Blood perfusion in the STA and CCA was assessed by Doppler ultrasonography at three different time intervals: at the experimental onset (T0), 3 weeks of dietary supplement (T3), and after 6 weeks of observation (T6). Concomitantly, blood samples were withdrawn for hematobiochemical and hormonal changes. Results revealed no evidence of clinical abnormality, with some enhanced hematological parameters and antioxidant (SOD and GPX) levels in goats of the Se-Pro and Pro groups. High concentrations of FSH were found in the Se-Pro at T6 compared to its values in other groups. Similarly, testosterone levels were elevated in the Pro and Se-Pro groups at T3 compared to other time points. There were significant increases in levels of IGF-1 in the Pro and Se-Pro groups compared to the NC group. Significant (P < 0.05) increases in the values of the blood volume within the CCA and the STA were noted in the Se-Pro group, and the highest values were observed at T6 (CCA, 427.4 ± 33 ml/min; STA, 49.9 ± 5.0 ml/min). In conclusion, supra-nutritional organic selenium improves some hematobiochemical parameters, reproductive hormones, and the blood perfusion within the CCA and STA in goats.
Afficher plus [+] Moins [-]Sorption behavior of Arachis hypogaea shells against Ag+ ions and assessment of antimicrobial properties of the product Texte intégral
2020
Staroń, Paweł | Pszczółka, Krzysztof | Chwastowski, Jarosław | Banach, Marcin
The paper presents sorption behavior of Arachis hypogaea shells towards silver ions and possibility of their use as antimicrobial product. During the modification process of the natural sorbent, equilibrium tests were carried out. Moreover, the possibility of obtaining biocomposite Arachis hypogaea shells/nAg has been determined, and its antimicrobial properties have been evaluated. Additionally, sorption kinetics has been calculated. In the last step, silver ions were desorbed. The conducted equilibrium tests allowed to adjust the sorption isotherm model and determine the sorption capacity of tested material. This process is best described by Freudlich’s isotherm, and the sorption capacity is equal to 12.33 mg/g. On the basis of kinetic studies, the chemical nature of this process has been proved (by choosing a pseudo-second order model for the sorption process). It has been confirmed that the obtained peanut shells modified with silver ions have antimicrobial properties. The tests allowed to obtain 100% inhibition of Aspergillus niger and ~ 98% Escherichia coli.
Afficher plus [+] Moins [-]One-pot synthesis of Cr(III)-incorporated Zr(IV) oxide for fluoride remediation: a lab to field performance evaluation study Texte intégral
2020
Kanrar, Sarat | Ghosh, Abir | Ghosh, Ayan | Mondal, Arpan | Sadhukhan, Mriganka | Ghosh, Uday Chand | Sasikumar, Palani
A low-cost Cr(III)-incorporated Zr(IV) bimetallic oxide (CZ) was synthesized by simple chemical precipitation method for removal of fluoride from contaminated water. The physicochemical properties of CZ before and after fluoride removal were established with several instrumental techniques such as TEM with elemental mapping, SEM with EDX, XRD, IR, XPS, zeta potential measurement, etc. Batch adsorption technique were carried out to understand the factors affecting fluoride adsorption, such as effects of initial pH, adsorbent dose, co-occurring ions, contact time, and temperature. The maximum adsorption capacity observed at pH between 5 and 7. The fluoride adsorption processes on CZ obeyed the pseudo-second-order rate equations and both Freundlich and DR isotherm models. The maximum adsorption capacity of 90.67 mg g⁻¹ was obtained. The thermodynamic parameters ΔH⁰ (positive), ΔS⁰ (positive), and ΔG⁰ (negative) indicating the fluoride sorption system was endothermic, spontaneous, and feasible. The CZ also successfully used as fluoride adsorbent for real field contaminated water collected from the Machatora district, Bankura, West Bengal, India. Graphical abstract Schematic representation of CZ synthesis and its application for lab as well as field water purification purpose.
Afficher plus [+] Moins [-]Assessing the response of five tree species to air pollution in Riyadh City, Saudi Arabia, for potential green belt application Texte intégral
2020
Alotaibi, Majed D. | Alharbi, Badr H. | Al-Shamsi, Mohammed A. | Alshahrani, Thobayet S. | Al-Namazi, Ali A. | Alharbi, Saif F. | Alotaibi, Fahad S. | Qian, Yaling
Tree species (including Eucalyptus camaldulensis, Ziziphus spina-christi, Albizia lebbeck, Prosopis juliflora, Pithecellobium dulce, and Ficus altissima) were investigated to elucidate their appropriates for green belt application. Leaf samples were collected from four different locations in Riyadh: (1) residential; (2) dense traffic; (3) industrial; and (4) reference sites located approximately 20 km away from the city of Riyadh. Leaves collected from the industrial site showed the highest leaf area reduction. The smallest reduction of leaf areas was observed for F. altissima (11.6%), while the highest reduction was observed for P. juliflora (34.8%). Variations in the air pollution tolerance index (APTI) coupled with the anticipated performance index (API) for each species were examined. The APTI value of Z. spina-christi was highest (58.5) at the industrial site while the lowest APTI value was for P. juliflora (14) at the reference site. Correlation coefficient and linear regression analyses determined that the correlation between the ascorbic acid content and APTI is positive and significantly strong. Our findings indicate that urban green planning in Riyadh should include growing F. altissima on roadsides as well as in heavy industrial locations followed by Z. spina-christi and A. lebbeck according to their API and APTI performances.
Afficher plus [+] Moins [-]Impacts of anthropogenic activities and calculation of the relative risk of violating surface water quality standards established by environmental legislation: a case study from the Piracicaba and Paraopeba river basins, Brazil Texte intégral
2020
Soares, Ana Luiza Cunha | Pinto, Carolina Cristiane | Oliveira, Sílvia Corrêa
The nonparametric test of Kruskal–Wallis and relative risk were used to evaluate surface water quality allowed to an identification of the most degraded water bodies in Piracicaba River and Paraopeba River basins, two important hydrographic basins in Brazil. Total manganese, dissolved iron, and fecal contamination indicator were considered the most relevant parameters for the characterization of water quality in the basins. The Peixe River, in Nova Era, and Pedras Creek, in Betim, were considered the most impacted water bodies in the Piracicaba River and Paraopeba River basins, respectively. The analysis of violations and the relative risk confirmed that both basins are subject to impacts resulting from economic activities. On comparing the relative risks, the Paraopeba River basin showed a higher risk of violation for 5-day biological oxygen demand (BOD₅), total manganese, total phosphorus, total suspended solids, and turbidity, while the Piracicaba River basin showed a higher risk of violation for fecal contamination indicator. The release of domestic sewage and industrial effluents, mining activities, and diffuse pollution from agriculture and pasture areas were responsible for the surface water quality deterioration in these basins. The results show the need for investment in basic sanitation, improved treatment efficiency for industrial effluents, adequate soil management, riparian vegetation preservation, and environmental education actions.
Afficher plus [+] Moins [-]Adsorption of heavy metal from industrial wastewater onto low-cost Malaysian kaolin clay–based adsorbent Texte intégral
2020
Chai, Jia-Boon | Au, Pek-Ing | Mubarak, Nabisab Mujawar | Khalid, Mohammad | Ng, Wendy Pei-Qin | Jagadish, Priyanka | Walvekar, Rashmi | Abdullah, Ezzat Chan
Adsorption capacity and percentage removal efficiency of Cu(II) and Ni(II) ions were studied and compared between raw kaolinite and acid-activated kaolinite. Acid-activated kaolin was prepared by refluxing raw kaolinite with concentrated sulphuric acid followed by calcination to enhance its surface properties and adsorption ability. Both raw and acid-activated kaolinite samples were characterized by Fourier transform infrared spectroscopy, energy dispersive X-ray, scanning electron micrograph and zeta potential analysis. Upon acid treatment, acid-activated kaolinite was discovered to have altered chemical composition and larger BET surface area as compared with raw kaolinite. The batch adsorption studies on aqueous solution were performed under different factors such as contact time, pH condition, adsorbent dosage, initial metal ion concentration and temperature. The optimum condition was selected for each factor including a contact time of 60 min, pH of 7.0, adsorbent dosage of 0.1 g, initial metal ion concentration of 100 mg/L and temperature of 25 °C. Then, the adsorption studies on wastewater samples were carried out at the selected optimum conditions. Acid-activated kaolinite always had better adsorption capacity and percentage removal efficiency than raw kaolinite due to the increasing amount of negative charges on the adsorbent surface and the number of metal ion binding sites upon acid treatment. The adsorption kinetic obtained was well described by the pseudo-second-order model, whereas the adsorption isotherms obtained were well described by either the Freundlich or the Langmuir adsorption model. The results showed that acid-activated kaolinite adsorbent is a better option as a favourable and feasible commercial low-cost adsorbent for wastewater treatment.
Afficher plus [+] Moins [-]Achieving environmental sustainability through information technology: “Digital Pakistan” initiative for green development Texte intégral
2020
Ahmad Nizam Hassan, | Zaman, Khalid | Khan, Khan Burhan | Batool, Rubeena | Khurshid, Muhammad Adnan | Shoukry, Alaa Mohamd | Sharkawy, Mohamed A. | Aldeek, Fares | Khader, Jameel | Gani, Showkat
The importance of information and communication technologies (ICTs) in environmental resource management opens a new debate for the policy makers in order to promote green technologies to mitigate high mass carbon emissions across the globe. “Digital Pakistan” initiative is taken by the government that aimed to use technology for country’s social welfare, which further be enhance for achieving environmental sustainability over a time horizon. This study examined the long-run relationship between ICTs, energy demand, and carbon emissions in a context of Pakistan by using a time series data from 1975 to 2017. The results show that energy demand increases economic growth in the short-run while it decreases economic growth in the long-run. The country’s economic growth substantially increases along with an increase in trade openness and mobile-telephone subscription (ICTs) in the short-run; however, the result is changed in the long-run due to increase in carbon emissions in a given time period. The results provoke that continued economic growth and ICT penetration substantially decreases energy demand, whereas urbanization increases energy demand in a country. The results show that variations in emissions associated with proportionate changes in ICTs penetration, economic growth, energy demand, and population growth. Human capital, trade openness, and energy demand are the significant drivers of ICT penetration in a country. The study concludes that the use of green technology is imperative for achieving long-term sustainable growth in a country.
Afficher plus [+] Moins [-]Impairment of testicular development in rats exposed to acephate during maternal gestation and lactation Texte intégral
2020
Sampaio, Carolina Ferreira | Prates, Kelly Valério | Siervo, Gláucia Eloisa Munhoz Lion | Mathias, Paulo Cézar de Freitas | Fernandes, Glaura Scantamburlo Alves
Acephate is an organophosphate insecticide that disrupts the endocrine system and impairs the male reproductive system. Thus, the aim of the present study was to evaluate whether exposure to acephate during maternal gestation and lactation histologically damages the testes of male Wistar rats in adulthood. For this study, adult Wistar rats were divided into the following groups: ACE-mother, (2.5 mg/kg/bw, gestational day (GD) 7 to postnatal day (PND) 21) and oil-mother (corn oil (control), GD 7 to PND 21). The male offspring (PND 90) were euthanized, and the prostates and testes were collected and weighed. The testes were utilized for histopathological analyses and to determine the sperm count. A spermatogenesis kinetic analysis revealed an increased number of seminiferous tubules in stages I–VI in the ACE-mother group. Additionally, we observed a decrease in the epithelium and the diameters of the evaluated seminiferous tubules and in the number of Sertoli cells in the group exposed to acephate. The sperm count analysis showed no difference between the groups. We conclude that maternal exposure to the pesticide acephate did not affect testicular function, but led to the impairment of testicular development and morphology of the tissue in adulthood.
Afficher plus [+] Moins [-]Assessment of the ecotoxicity of the pharmaceuticals bisoprolol, sotalol, and ranitidine using standard and behavioral endpoints Texte intégral
2020
Godoy, Aline Andrade | Domingues, Inês | de Carvalho, Luciano Bastos | Oliveira, Ádria Caloto | de Jesus Azevedo, Carina Cristina | Taparo, Jeniffer Marins | Assano, Patrícia Kushim | Mori, Vivien | de Almeida Vergara Hidalgo, Vitória | Nogueira, António José Arsénia | Kummrow, Fábio
The pharmaceuticals bisoprolol (BIS), sotalol (SOT), and ranitidine (RAN) are among the most consumed pharmaceuticals worldwide and are frequently detected in different aquatic ecosystems. However, very few ecotoxicity data are available in the literature for them. To help fill these data gaps, toxicity tests with the algae Raphidocelis subcapitata, the macrophyte Lemna minor, the cnidarian Hydra attenuata, the crustacean Daphnia similis, and the fish Danio rerio were performed for assessing the ecotoxicity of these pharmaceuticals. Standard, as well as non-standard endpoint, was evaluated, including the locomotor behavior of D. rerio larvae. Results obtained for SOT and RAN showed that acute adverse effects are not expected to occur on aquatic organisms at the concentrations at which these pharmaceuticals are usually found in fresh surface waters. On the other hand, BIS was classified as hazardous to the environment in the acute III category. Locomotor behavior of D. rerio larvae was not affected by BIS and RAN. A disturbance on the total swimming distance at the dark cycle was observed only for larvae exposed to the highest test concentration of 500 mg L⁻¹ of SOT. D. similis reproduction was affected by BIS with an EC₁₀ of 3.6 (0.1–34.0) mg L⁻¹. A risk quotient (RQ) of 0.04 was calculated for BIS in fresh surface water, considering a worst-case scenario. To the best of our knowledge, this study presents the first chronic toxicity data with BIS on non-target organisms.
Afficher plus [+] Moins [-]Magnetite-based catalysts for wastewater treatment Texte intégral
2020
Masudi, Ahmad | Harimisa, Grace Erlinda | Ghafar, Nawal Abdul | Jusoh, Nurfatehah Wahyuny Che
The increasing number and concentration of organic pollutants in water stream could become a serious threat in the near future. Magnetite has the potential to degrade pollutants via photocatalysis with a convenient separation process. This study discusses in detail the control size and morphology of magnetite nanoparticles, and their composites with co-precipitation, hydrothermal, sol-gel, and electrochemical route. Further photocatalytic enhancement with the addition of metal and porous support was proposed. This paper also discussed the technology to extend the lifetime of recombination through an in-depth explanation of charge transfer. The possibility to use waste materials as catalyst support was also elucidated. However, magnetite-based photocatalysts still require many improvements to meet commercialization criteria.
Afficher plus [+] Moins [-]