排序方式: 共有21条查询结果,搜索用时 62 毫秒
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Sandeep Yadav Varsha Srivastava Sushmita Banerjee Fethiye Gode Yogesh C. Sharma 《Environmental science and pollution research international》2013,20(1):558-567
This paper highlights the utility of riverbed sand (RS) for the treatment of Ni(II) from aqueous solutions. For enhancement of removal efficiency, RS was modified by simple methods. Raw and modified sands were characterized by scanning electron microscope (SEM), Energy Dispersive Spectroscopy (EDS), and Fourier Transform Infrared Spectroscopy (FTIR) to investigate the effect of modifying the surface of RS. For optimization of various important process parameters, batch mode experiments were conducted by choosing specific parameters such as pH (4.0–8.0), adsorbent dose (1.0–2.0 g), and metal ion concentrations (5–15 mg/L). Removal efficiency decreased from 68.76 to 54.09 % by increasing the concentration of Ni(II) in solution from 5 to 15 mg/L. Removal was found to be highly dependent on pH of aqueous solutions and maximum removal was achieved at pH 8.0. The process of removal follows first-order kinetics, and the value of rate constant was found to be 0.048 min?1 at 5 mg/L and 25 °C. Value of intraparticle diffusion rate constant (k id) was found to be 0.021 mg/g min1/2 at 25 °C. Removal of Ni(II) decreased by increasing temperature which confirms exothermic nature of this system. For equilibrium studies, adsorption data was analyzed by Freundlich and Langmuir models. Thermodynamic studies for the present process were performed by determining the values of ΔG°, ΔH°, and ΔS°. Negative value of ?H° further confirms the exothermic nature of the removal process. The results of the present investigation indicate that modified riverbed sand (MRS) has high potential for the removal of Ni(II) from aqueous solutions, and resultant data can serve as baseline data for designing treatment plants at industrial scale. 相似文献
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Camptothecin (CPT), a broad spectrum antineoplastic agent, is known to induce oxidative stress and mitochondria are among the main sources of intracellular reactive oxygen species (ROS). We investigated the merit of vitamins E and C supplementation on CPT-induced mitochondrial alterations in vitro. Following treatment of isolated liver mitochondria with CPT, we assessed the mitochondrial membrane permeability transition (MPT), concentration of malondialdehyde, antioxidants and activities of the enzymes of the respiratory chain and Krebs cycle. Our results provide evidence that CPT caused mitochondrial swelling, increased lipid peroxidation and transition of mitochondrial permeability. The CPT lowered the levels of reduced mitochondrial thiols suggesting that thiol oxidation is the mechanism underlying CPT-induced MPT. Identical experiments were also performed after preincubating the mitochondria with vitamins E and C. It was found that vitamins E and C pretreatment inhibited the deleterious effects of CPT and loss of enzyme activity was restored by antioxidant supplementation. Our results suggest that the toxicity of CPT was mediated by an increase in ROS production by mitochondria. However, the addition of vitamins E or C ameliorated the oxidative stress. We propose that an attempt to counteract the deleterious consequences of chemotherapy with nutritional therapies may be a rational approach in superior patient care especially in a disease like cancer. 相似文献
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Tiwari Varsha Kumar Manish Tiwari Abhishek Sahoo Biswa Mohan Singh Sunil Kumar Suresh Saharan Renu 《Environmental science and pollution research international》2021,28(46):64987-65013
Environmental Science and Pollution Research - Coronaviruses are terrifically precise and adapted towards specialized respiratory epithelial cells, observed in organ culture and human volunteers... 相似文献
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Bombaywala Sakina Dafale Nishant A. Jha Varsha Bajaj Abhay Purohit Hemant J. 《Environmental science and pollution research international》2021,28(9):10780-10790
Environmental Science and Pollution Research - Prophylactic usage and high persistent nature of several antibiotics have put selective pressure on the native microbial population that led to the... 相似文献
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Visibility impairing aerosols in the urban atmosphere of Delhi 总被引:1,自引:0,他引:1
Singh T Khillare PS Shridhar V Agarwal T 《Environmental monitoring and assessment》2008,141(1-3):67-77
To study the visual air quality of Delhi, size fractionated aerosols – coarse and fine fractions of PM10 – were collected and analysed for and EC at three sites with different background activities. The analysed species constitute a smaller portion of coarse fraction
(39%) but a larger portion of fine fraction (69%). The sampling was performed from June 2003 to November 2003 which covers
monsoon and post monsoon seasons.Aerosol data was used to describe the spatial variation of Visibility Range as a function
of chemical composition of visibility impairing aerosols. During the study period, visibility was found to be poor varying
between 4.7 and 13 km with an average value of 9.4 km. It is observed that visibility impairment was more due to carbonaceous
aerosol followed by sulphate. 相似文献
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Gulab Singh Anish Kumari Arpana Mittal Varsha Goel Anita Yadav Neeraj Kumar Aggarwal 《Journal of Polymers and the Environment》2013,21(2):441-449
The present study describes the treatment of sugar industry waste water and its use as a potential low cost substrate for production of bioplastic by Bacillus subtilis NG05. The B. subtilis NG05 grow at the rate of 0.14 g h?1 L?1 of production media used and accumulate the 50.1 % of poly β-hydroxybutyrate (PHB). The phase contrast microscopy revealed the presence of PHB granules in B. subtilis NG05 which was further confirmed by Fourier transform infrared spectroscopy and 1H-nuclear magnetic resonance. The polymer was further analysed by differential scanning calorimetry. PHB production yield was achieved up to 4.991 g L?1 with Sugar industry waste water as sole nutrient source. Thus the process provided dual benefits of conversion of a waste material into value added product, PHB and waste management. 相似文献
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Lara Gotha Vagisha Pruthi Nimrah Abbasi Abhaya V. Kulkarni Paige Church James M. Drake Jose C.A. Carvalho Yenge Diambomba Varsha Thakur Greg Ryan Tim Van Mieghem 《黑龙江环境通报》2020,40(12):1499-1507
Worldwide, about 150 000 infants are born with spina bifida yearly, making this condition one of the most common fetal central nervous system anomalies compatible with life. Over the last decade, major changes have been introduced in the prenatal diagnosis and management of spina bifida. In this review, we provide a brief summary of the current management of fetal spina bifida and present essential information that should be provided to expecting parents when their fetus has been diagnosed with spina bifida. This information is focused around common parental questions, as encountered in our typical clinical practice, to facilitate knowledge translation. 相似文献
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D’souza Oshin Jacintha Hiremani Vishram D. Gasti Tilak Goudar Naganagouda L Varsha S. Masti Saraswati P. Mudigoudra Bhagyavana S. Malabadi Ravindra B. Chougale Ravindra B. 《Journal of Polymers and the Environment》2022,30(7):2888-2904
Journal of Polymers and the Environment - In this study eco-friendly composite films were prepared based on poly(vinyl alcohol) (PVA) containing different content of Basella alba stem extract (BA)... 相似文献