ASSESSMENT OF IMPACT OF COVID-19 LOCKDOWN ON AIR QUALITY IN NATIONAL CAPITAL REGION OF NEW DELHI, INDIA

After the World Health Organization declared COVID-19 as pandemic on 11th March 2020, the Indian government adopted a complete phased lockdown strategy starting from 23rd March until 31st May 2020. During this period, road/rail/air traffic, industrial operations and offices were completely restricted except for the essential services. Here, an attempt was made to assess the effect of the lockdown period on five pollutants: PM10, PM2.5, SO2, NOx, and ozone at three sites, Jahangirpuri in North Delhi and Sonipat and Panipat townships located along the national highway leading to north India. These pollutants, except ozone, decreased at all sites during lockdown phase 1 compared to before lockdown. PM2.5 load reduced by 28.1, 33.5, and 40.8 % at Jahangirpuri, Sonipat and Panipat, respectively. PM10 remained either close to or higher than National Ambient Air Quality Standards (NAAQS) due to prevailing high-speed winds. NO2, a precursor for formation of O3 decreased consistently at all sites, except an increase in phase 3 at Panipat whereas O3 consistently increased. This was a paradoxical situation as O3 is formed by photochemical reactions among NOx and volatile organic compounds, which require further detailed studies. These observations indicate that air pollutants decreased specific to the site(s) and pollutant(s). Such restriction can be applied in the future to control air pollution in this region

Assessment of bioavailable metals in the sediments of Yamuna flood plain using two different single extraction procedures

AbstractThough flood plains are considered as most fertile areas across the world but they have come under severe stress due to the flow of untreated domestic and industrial effluents and therefore, needed attention for its characterisation and subsequent treatment plans. The sediment samples, collected at 0–15, 15–35 and 30–60 cm depth levels during pre and post monsoon season from east and west sides of the river Yamuna around the national capital region of Delhi, were assessed for bioavailability of lead (Pb), zinc (Zn) and nickel (Ni) using Ethylene Diamine Tetra Acetic Acid (EDTA) and acetic acid. The average concentrations of Zn (25 ± 6 mg kg−1) and Pb (33 ± 6 mg kg−1) leached in EDTA were higher than that of in acetic acid (Zn: 22 ± 6 mg kg−1; Pb: 24 ± 5 mg kg−1) whereas Ni (24 ± 6 mg kg−1) leached more in acetic acid compared to EDTA (Ni: 21 ± 4 mg kg−1). The bioavailable concentrations of metals were comparable among 0–15 and 15–35 cm depth samples but decreased in 35–60 cm depth samples. The post monsoon samples contained lower amounts of total metals in comparison to pre-monsoon samples, an indication of washout/dilution effects of flood/high water flow during monsoon season. The percentages of metals, with reference to their respective total concentrations, in the flood plain sediments as extracted by EDTA were in the range of 14–47% for Pb, 17–54% for Zn, and 15–39% for Ni. The Zn, Ni and Pb were soluble in acetic acid in the range of 12–39%, 16.7–36.5% and 14–36%, respectively. The chemical nature of extracting agent affected the metal leaching. Acetic acid, a weak acid, extracted the metals that were present in exchangeable fraction and easily movable whereas EDTA, hexa-dentate complexing agent, extracted metals from carbonate and organically bound fractions of the sediment samples. This could result in metal accumulation in the floodplains, biomagnification, adverse effects on water quality, sediments, aquatic lives and the vegetables grown in the flood plains. Steps should be taken to stop the direct flow of untreated waste into the river to safeguard the floodplains and life forms

Encapsulation of catechin and epicatechin on BSA NPS improved their stability and antioxidant potential

Nanoencapsulation of antioxidant molecules on protein nanoparticles (NPs) could be an advanced approach for providing stable, better food nutraceuticals and anticancer drugs. The bioavailability and stability of catechin (CAT) and epicatechin (ECAT) were very poor. In the present study, the CAT and ECAT were loaded on bovine serum albumin (BSA) NPs following desolvation method. The transmission electron microscope (TEM) and atomic force microscope (AFM) recorded size of CAT-BSA NPs and ECAT-BSA NPs were 45 ± 5 nm and 48 ± 5 nm respectively. The encapsulation efficiency of CAT and ECAT on BSA NPs was found to be 60.5 and 54.5 % respectively. CAT-BSA NPs and ECAT-BSA NPs show slow and sustained in vitro release. The CAT-BSA NPs and ECAT-BSA NPs were stable in solution at various temperatures 37°C, 47°C and 57°C. DPPH assay revealed that CAT and ECAT maintained their functional activity even after encapsulation on BSA NPs. Furthermore, the efficacy of CAT-BSA NPs and ECAT-BSA NPs determined against A549 cell lines was found to be improved. CAT and ECAT aptly encapsulated in BSA NPs, showed satisfactory sustained release, maintained antioxidant potential and found improved efficacy. This has thus suggested their more effective use in food and nutraceuticals as well as in medical field

Post-Transcriptional Silencing of Flavonol Synthase mRNA in Tobacco Leads to Fruits with Arrested Seed Set

Flavonoids are synthesized by phenylpropanoid pathway. They are known to participate in large number of physiological and biochemical processes in plants. Parthenocarpy and male sterility has earlier been reported by silencing chalcone synthase (CHS) encoding gene. Silencing of CHS has blocked the synthesis of most of useful flavonoids including flavan-3-ols and flavonols. Also, these studies could not identify whether parthenocarpy/male sterility were due to lack of flavan-3-ols or flavonols or both. Flavonol synthase (FLS) is an important enzyme of flavonoid pathway that catalyzes the formation of flavonols. In this article, we propose a novel strategy towards the generation of seedless or less-seeded fruits by downregulation of flavonol biosynthesis in tobacco (Nicotiana tabacum cv Xanthi) through post-transcriptional gene silencing (PTGS) of FLS encoding mRNA. The FLS silenced lines were observed for 20-80% reduction in FLS encoding gene expression and 25–93% reduction in flavonol (quercetin) content. Interestingly, these FLS silenced tobacco lines also showed reduction in their anthocyanidins content. While the content of flavan-3-ols (catechin, epi-catechin and epi-gallocatechin) was found to be increased in FLS silenced lines. The delayed flowering in FLS silenced lines could be due to decrease in level of indole acetic acid (IAA) at apical region of their shoots. Furthermore, the pollen germination was hampered and pollens were unable to produce functional pollen tube in FLS silenced tobacco lines. Pods of FLS silenced lines contained significantly less number of seeds. The in vitro and in vivo studies where 1 µM quercetin was supplied to germination media, documented the restoration of normal pollen germination and pollen tube growth. This finding identified the role of flavonols particularly quercetin in pollen germination as well as in the regulation of plant fertility. Results also suggest a novel approach towards generation of seedless/less-seeded fruits via PTGS of FLS encoding gene in plants

Nanoencapsulation for drug delivery

Nanoencapsulation of drug/small molecules in nanocarriers (NCs) is a very promising approach for development of nanomedicine. Modern drug encapsulation methods allow efficient loading of drug molecules inside the NCs thereby reducing systemic toxicity associated with drugs. Targeting of NCs can enhance the accumulation of nanonencapsulated drug at the diseased site. This article focussed on the synthesis methods, drug loading, drug release mechanism and cellular response of nanoencapsulated drugs on liposomes, micelles, carbon nanotubes, dendrimers, and magnetic NCs. Also the uses of these various NCs have been highlighted in the field of nanotechnology

Cost-Benefit Analysis of a Redundant System with Server having Refreshment Facility Subject to Inspection

In this paper two units cold standby system has been discussed with the facility that server inspect the failed unit before repair/replacement of the unit and server may allow to take refreshment whenever needed. The operative unit may fail directly from normal mode and the cold standby unit may be failed owing to remain unused for a longer period of time. There is single server who serves the dual purpose of inspection and repair immediately whenever required. Also, after having refreshment the server may eventually perform the better service efficiently. The time to take refreshment and repair activity follows negative exponential distribution whereas the distributions of unit failure and server failure are taken as arbitrary with different probability density functions. The expressions of various stochastic measures are analyzed in steady state using semi-Markov process and regenerative point technique. The graphs are sketched for arbitrary values of the parameters to delineate the behavior of some important performance measures to check the efficacy of the system model under such situations

Organic fouling in forward osmosis: A comprehensive review

Organic fouling in the forward osmosis process is complex and influenced by different parameters in the forward osmosis such as type of feed and draw solution, operating conditions, and type of membrane. In this article, we reviewed organic fouling in the forward osmosis by focusing on wastewater treatment applications. Model organic foulants used in the forward osmosis literature were highlighted, which were followed by the characteristics of organic foulants when real wastewater was used as feed solution. The various physical and chemical cleaning protocols for the organic fouled membrane are also discussed. The study also highlighted the effective pre-treatment strategies that are effective in reducing the impact of organic fouling on the forward osmosis (FO) membrane. The efficiency of cleaning methods for the removal of organic fouling in the FO process was investigated, including recommendations on future cleaning technologies such as Ultraviolet and Ultrasound. Generally, a combination of physical and chemical cleaning is the best for restoring the water flux in the FO process. 2020 by the authors.This research was funded by an NPRP grant (NPRP10-0117-170176) from the Qatar National Research Fund (a member of Qatar Foundation). This is the format recommended by the funding organization. Candidate S.Y. would like to acknowledge scholarship support from the University of Technology Sydney under UTS President's Scholarship and International Research Scholarship (IRP). In addition, this publication was possible by an NPRP grant (NPRP10-0117-170176) from the Qatar National Research Fund (a member of Qatar Foundation). The findings achieved herein are solely the responsibility of the authors.Scopu

Biomass degradation : Challenges and strategies in extraction and fractionation of hemicellulose

Extraction and fractionation of hemicellulose from complex lignocellulosic biomass are crucial steps to acquiring purified hemicellulose that can probably used in biofuel and biochemical sectors. Yet, several challenges have impeded for obtaining the hemicellulose fraction as it involves the complexity of extracting and fractioning hemicellulose. In this study, the authors have discussed the outline of the most prospective and effective method for separation, extraction, and purification of hemicellulose-rich biomass. A current overview of challenges and problems in hemicellulose separation was addressed. Subsequently, the influence of heterogeneous biomass types, cultivation and harvesting times, accessible surface areas, acetyl and other functional groups on purity was observed. On the other hand, several proper strategies efficiently employed in hemicellulose extraction and fractionation are provided. The biochemical process gives a highly positive contribution to sustaining hemicellulose-based bioproducts. Biological pre-treatment of lignocellulose using enzymes and bacteria is convinced as the most effective and efficient method to reduce the lignin content and to improve the purity due to less inhibitory and minimal coke formation. Saccharomyces cerevisiae has been widely used in the hemicellulose-based bioprocess due to resulting in high conversion (>80%) and yield (>70%). The hydrothermal method followed by multistep ultrafiltration treatment generated the highest hemicellulose purity (100%) and by-product removal (94.4–99.2 wt%). Comprehensive strategies for hemicellulose extraction and fractionation involving biological and non-biological treatments are also the highlights of this article

Metabolite of the pesticide DDT and incident type 2 diabetes in urban India

BACKGROUND: Previous epidemiological studies, largely conducted in high-income countries and cross-sectional, have suggested a relatively strong association between exposure to dichlorodiphenyldichloroethylene (DDE), a metabolite of the pesticide dichlorodiphenyltrichloroethane (DDT), and type 2 diabetes. DDT is widely used in India and the prevalence of type 2 diabetes there is increasing, but the association between these factors has not been explored to date. OBJECTIVE: The objective was to estimate the association of the p,p' isomer of DDE with incident type 2 diabetes in India. METHODS: A nested case-control study was conducted in a representative prospective cohort of adults from two cities in India. Participants were enrolled in 2010-11 (n = 12,271) and followed for annual assessment of chronic diseases including type 2 diabetes. Baseline plasma samples from incident cases of diabetes (n = 193) and sex-city-matched controls (n = 323) were selected for analysis of p,p-DDE. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using conditional logistic regression. RESULTS: At baseline, cases had higher p,p-DDE concentrations: geometric mean (95% CI) 330 (273-399) ng/g lipid compared to 223 (189-262) ng/g lipid among controls. Delhi participants had higher p,p-DDE concentrations: 579 (521-643) ng/g lipid compared to 122 (102-145) ng/g lipid in Chennai. In unadjusted models, being in the highest versus lowest quartile of p,p-DDE was associated with a more than doubling of the odds of diabetes: unadjusted OR (95% CI), 2.30 (1.19, 4.43). However, this effect was no longer significant after adjustment for age: adjusted (95% CI), 0.97 (0.46, 2.06). DISCUSSION: Results suggest that levels of p,p'-DDE in Delhi are exceptionally high, but we did not observe a significant association between p,p-DDE and incident type 2 diabetes. As this is the first study to evaluate this association in India, more studies are needed to inform our understanding of the association in this context, including potential routes of exposure

Potential Applications of Graphene-Based Membrane in Solution Purification Processes

University of Technology Sydney. Faculty of Engineering and Information Technology.Climate change with industrial and environmental pollution are among the reasons for water quality deterioration. Unfortunately, conventional polymeric membranes have inherent limitations, such as low separation or rejection rate, fouling, limited water flux, and high energy consumption. Two-dimensional (2D) based layered materials with tunable chemical functionalities and surface charge properties have emerged for on-demand applications, including membrane technology. However, the instability of graphene oxide (GO) membranes during operation is one of the biggest challenges for its practical applications. Therefore, it is important to improve the stability of GO membranes without losing their physiochemical properties. This thesis aims to develop advanced performance GO membranes for water purification. Initially, research was conducted to investigate the pressure-assisted method for fabricating a GO membrane using polyvinyl alcohol (PVA) as adhesive materials for swelling control and molybdenum disulfide as nanospacer. The next study evaluated synergistic ionic complexation between 1D-CNT (carbon nanotubes), 2D-GO, and PVA to overcome the permeability-selectivity trade-off. Thermal treatment of GO membranes was also investigated in this study. Later, part of this thesis is focused on developing a proof of concept of preparing an antifouling GO membrane using a non-solvent induced phase separation method for a highly selective membrane. The potential of vanillin and GO for various model foulants and landfill leachate wastewater was investigated in this study. Finally, a surface modification technique was used to modify the commercially available loose nanofiltration (NF) membrane. In this study, kappa-carrageenan (κ-CGN)/GO composite has been used to modify a commercial NF membrane to improve salt rejection antifouling properties when landfill leachate wastewater is the feed solution. The techniques presented in this thesis demonstrates are not only simple and effective but can also be applied to a wide range of membrane substrates and even large-scale membrane development. GO membranes' mechanical integrity and structural stability are evaluated for 72 hours of operation; however, low water permeability is still challenging. Therefore, studies should prepare an efficient GO membrane of high permeability without compromising its rejection rate and stability. At the same time, the mechanical properties and stability of the GO membrane should be explored to understand its potential applications better