In the present investigation, GO was prepared by exfoliation of graphite using modified Hummer's method and then reduced using hydrazine hydrate (reducing agent) to produce rGO. XRD, FESEM, Raman, ...FTIR spectrophotometer and TGA were used for characterization of GO and rGO. XRD images reveal crystalline structure for both GO and rGO. The d‐spacing is observed to be reduced for rGO as compared to that for GO because of removal of oxygen containing functional groups. Raman excitation peaks were obtained for two laser wavelengths 532 and 785 nm. Ratio of intensities of D and G bands (ID/IG) increase for rGO due to increase in order by reduction, implying restoration of the p‐conjugation. The bands are narrower for rGO.TGA thermograms show a higher overall loss of weight for GO in the temperature range 0–1000 °C under N2 flow. Intensity of FTIR peaks of oxide, hydroxyl and alkoxy groups decreases significantly on reduction. FESEM image shows more corrugated surface of rGO as compared to GO. It is expected that this investigation would be useful to develop GO/rGO based gas sensors to detect minute concentration of gases.
Carbon nanotubes (CNT) represent one of the most unique materials in the field of nanotechnology. CNT are the allotrope of carbon having sp2 hybridization. CNT are considered to be rolled-up graphene ...with a nanostructure that can have a length to diameter ratio greater than 1,000,000. CNT can be single-, double-, and multi-walled. CNT have unique mechanical, electrical, and optical properties, all of which have been extensively studied. The novel properties of CNT are their light weight, small size with a high aspect ratio, good tensile strength, and good conducting characteristics, which make them useful for various applications. The present review is focused on the structure, properties, toxicity, synthesis methods, growth mechanism and their applications. Techniques that have been developed to synthesize CNT in sizeable quantities, including arc discharge, laser ablation, chemical vapor deposition, etc., have been explained. The toxic effect of CNT is also presented in a summarized form. Recent CNT applications showing a very promising glimpse into the future of CNT in nanotechnology such as optics, electronics, sensing, mechanical, electrical, storage, and other fields of materials science are presented in the review.
Type 2 diabetes mellitus (T2DM) worldwide continues to increase, in particular in India. Early T2DM diagnosis followed by appropriate management will result in more cardiovascular event free life ...years. However, knowledge of the cardiovascular profile of newly diagnosed T2DM patients is still limited. The aim of this study was to understand the extent of cardiovascular disease (CVD) risk of newly diagnosed T2DM patients in India.
A cross sectional observational study was conducted to evaluate clinical laboratory and socio-demographic parameters of 5,080 newly diagnosed T2DM patients (48.3 ± 12.8 years of age; 36.7% female). In addition, we determined their cardiovascular risk according to the guidelines of the Lipid Association of India (LAI) and the criteria of the QRISK3 score.
Of the newly T2DM diagnosed patients in India 2,007(39.5%) were classified as "High risk" and 3,073 (60.5%) were classified as "Very high risk" based on LAI criteria. On average, patients had 1.7 ± 0.9 major atherosclerotic cardiovascular disease (ASCVD) risk factors. Low HDL-C value was the most frequent major risk (2,823; 55.6%) followed by high age (2,502; 49.3%), hypertension (2,141; 42.1%), smoking/tobacco use (1,078; 21.2%) and chronic kidney disease stage 3b or higher (568; 11.2%). In addition, 4,192 (82.5%) patients appeared to have at least one cholesterol abnormality and, if the latest LAI recommendations are applied, 96.5% (4,902) presented with lipid values above recommended targets. Based on the QRISK3 calculation Indian diabetes patients had an average CVD risk of 15.3 ± 12.3%, (12.2 ± 10.1 vs. 17.1 ± 13.5 p<0.001 for females and males, respectively).
Newly diagnosed Indian T2DM patients are at high ASCVD risk. Our data therefore support the notion that further extension of nationwide ASCVD risk identification programs and prevention strategies to reduce the occurrence of cardiovascular diseases are warranted.
KEY MESSAGE : A set of NILs carrying major blast resistance genes in a Basmati rice variety has been developed. Also, the efficacy of pyramids over monogenic NILs against rice blast pathogen ...Magnaporthe oryzae has been demonstrated. Productivity and quality of Basmati rice is severely affected by rice blast disease. Major genes and QTLs conferring resistance to blast have been reported only in non-Basmati rice germplasm. Here, we report incorporation of seven blast resistance genes from the donor lines DHMASQ164-2a (Pi54, Pi1, Pita), IRBLz5-CA (Pi2), IRBLb-B (Pib), IRBL5-M (Pi5) and IRBL9-W (Pi9) into the genetic background of an elite Basmati rice variety Pusa Basmati 1 (PB1). A total of 36 near-isogenic lines (NILs) comprising of 14 monogenic, 16 two-gene pyramids and six three-gene pyramids were developed through marker-assisted backcross breeding (MABB). Foreground, recombinant and background selection was used to identify the plants with target gene(s), minimize the linkage drag and increase the recurrent parent genome (RPG) recovery (93.5–98.6 %), respectively, in the NILs. Comparative analysis performed using 50,051 SNPs and 500 SSR markers revealed that the SNPs provided better insight into the RPG recovery. Most of the monogenic NILs showed comparable performance in yield and quality, concomitantly, Pusa1637-18-7-6-20 (Pi9), was significantly superior in yield and stable across four different environments as compared to recurrent parent (RP) PB1. Further, among the pyramids, Pusa1930-12-6 (Pi2+Pi5) showed significantly higher yield and Pusa1633-7-8-53-6-8 (Pi54+Pi1+Pita) was superior in cooking quality as compared to RP PB1. The NILs carrying gene Pi9 were found to be the most effective against the concoction of virulent races predominant in the hotspot locations for blast disease. Conversely, when analyzed under artificial inoculation, three-gene pyramids expressed enhanced resistance as compared to the two-gene and monogenic NILs.
In the present study, a total of 53 promising salt-tolerant genotypes were tested across 18 salt-affected diverse locations for three years. An attempt was made to identify ideal test locations and ...mega-environments using GGE biplot analysis. The CSSRI sodic environment was the most discriminating location in individual years as well as over the years and could be used to screen out unstable and salt-sensitive genotypes. Genotypes CSR36, CSR-2K-219, and CSR-2K-262 were found ideal across years. Overall, Genotypes CSR-2K-219, CSR-2K-262, and CSR-2K-242 were found superior and stable among all genotypes with higher mean yields. Different sets of genotypes emerged as winners in saline soils but not in sodic soils; however, Genotype CSR-2K-262 was the only genotype that was best under both saline and alkaline environments over the years. The lack of repeatable associations among locations and repeatable mega-environment groupings indicated the complexity of soil salinity. Hence, a multi-location and multi-year evaluation is indispensable for evaluating the test sites as well as identifying genotypes with consistently specific and wider adaptation to particular agro-climatic zones. The genotypes identified in the present study could be used for commercial cultivation across edaphically challenged areas for sustainable production.
The present study attempts to explore and compare the seasonal variability in chemical composition and contributions of different sources of fine and coarse fractions of aerosols (PM2.5 and PM10) in ...Delhi, India from January 2013 to December 2016. The annual average concentrations of PM2.5 and PM10 were 131 ± 79 μg m−3 (range: 17–417 μg m−3) and 238 ± 106 μg m−3 (range: 34–537 μg m−3), respectively. PM2.5 and PM10 samples were chemically characterized to assess their chemical components i.e. organic carbon (OC), elemental carbon (EC), water soluble inorganic ionic components (WSICs) and heavy and trace elements and then used for estimation of enrichment factors (EFs) and applied positive matrix factorization (PMF5) model to evaluate their prominent sources on seasonal basis in Delhi. PMF identified eight major sources i.e. Secondary nitrate (SN), secondary sulphate (SS), vehicular emissions (VE), biomass burning (BB), soil dust (SD), fossil fuel combustion (FFC), sodium and magnesium salts (SMS) and industrial emissions (IE). Total carbon contributes ∼28% to the total PM2.5 concentration and 24% to the total PM10 concentration and followed the similar seasonality pattern. SN and SS followed opposite seasonal pattern, where SN was higher during colder seasons while SS was greater during warm seasons. The seasonal differences in VE contributions were not very striking as it prevails evidently most of year. Emissions from BB is one of the major sources in Delhi with larger contribution during winter and post monsoon seasons due to stable meteorological conditions and aggrandized biomass burning (agriculture residue burning in and around the regions; mainly Punjab and Haryana) and domestic heating during the season. Conditional Bivariate Probability Function (CBPF) plots revealed that the maximum concentrations of PM2.5 and PM10 were carried by north westerly winds (north-western Indo Gangetic Plains of India).
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•Simultaneous sampling of PM2.5 and PM10 was carried out for 4 years (2013–2016).•Seasonal variations in composition and sources of PM2.5 and PM10 are studied in Delhi.•Secondary inorganic aerosol accounts for 21% of PM10 and 27% of PM2.5 mass with contrasting seasonal variations.•Traffic emission contributes greatly to PM10 while biomass burning to PM2.5, both being maximum in winters.•Maximum concentrations of PM2.5 and PM10 were coming from North West direction of Delhi (CBPF plots).
The present work explores the temporal and seasonal variabilities in composition and contributions of different sources to fine and coarse fractions of particulate matter over Delhi.
Aerosol emissions from biomass burning are of specific interest over the globe due to their strong radiative impacts and climate implications. The present study examines the impact of paddy crop ...residue burning over northern India during the postmonsoon (October–November) season of 2012 on modification of aerosol properties, as well as the long‐range transport of smoke plumes, altitude characteristics, and affected areas via the synergy of ground‐based measurements and satellite observations. During this period, Moderate Resolution Imaging Spectroradiometer (MODIS) images show a thick smoke/hazy aerosol layer below 2–2.5 km in the atmosphere covering nearly the whole Indo‐Gangetic Plains (IGP). The air mass trajectories originating from the biomass‐burning source region over Punjab at 500 m reveal a potential aerosol transport pathway along the Ganges valley from west to east, resulting in a strong aerosol optical depth (AOD) gradient. Sometimes, depending upon the wind direction and meteorological conditions, the plumes also influence central India, the Arabian Sea, and the Bay of Bengal, thus contributing to Asian pollution outflow. The increased number of fire counts (Terra and Aqua MODIS data) is associated with severe aerosol‐laden atmospheres (AOD500 nm > 1.0) over six IGP locations, high values of Ångström exponent (>1.2), high particulate mass 2.5 (PM2.5) concentrations (>100–150 µgm−3), and enhanced Ozone Monitoring Instrument Aerosol Index gradient (~2.5) and NO2 concentrations (~6 × 1015 mol/cm2), indicating the dominance of smoke aerosols from agricultural crop residue burning. The aerosol size distribution is shifted toward the fine‐mode fraction, also exhibiting an increase in the radius of fine aerosols due to coagulation processes in a highly turbid environment. The spectral variation of the single‐scattering albedo reveals enhanced dominance of moderately absorbing aerosols, while the aerosol properties, modification, and mixing atmospheric processes differentiate along the IGP sites depending on the distance from the aerosol source, urban influence, and local characteristics.
Key Points
Satellite and ground‐based monitoring of agriculture fires in northern India
Transport pathways, smoke plume characteristics, and affected areas
Variation of aerosol loading as a function of distance from the source
Supplementary immunization activities (SIAs) aim to interrupt measles transmission by reaching susceptible children, including children who have not received the recommended two routine doses of MCV ...before the SIA. However, both strategies may miss the same children if vaccine doses are highly correlated. How well SIAs reach children missed by routine immunization is a key metric in assessing the added value of SIAs.
Children aged 9 months to younger than 5 years were enrolled in cross-sectional household serosurveys conducted in five districts in India following the 2017–2019 measles-rubella (MR) SIA. History of measles containing vaccine (MCV) through routine services or SIA was obtained from documents and verbal recall. Receipt of a first or second MCV dose during the SIA was categorized as “added value” of the SIA in reaching un- and under-vaccinated children.
A total of 1,675 children were enrolled in these post-SIA surveys. The percentage of children receiving a 1st or 2nd dose through the SIA ranged from 12.8% in Thiruvananthapuram District to 48.6% in Dibrugarh District. Although the number of zero-dose children prior to the SIA was small in most sites, the proportion reached by the SIA ranged from 45.8% in Thiruvananthapuram District to 94.9% in Dibrugarh District. Fewer than 7% of children remained measles zero-dose after the MR SIA (range: 1.1–6.4%) compared to up to 28% before the SIA (range: 7.3–28.1%).
We demonstrated the MR SIA provided considerable added value in terms of measles vaccination coverage, although there was variability across districts due to differences in routine and SIA coverage, and which children were reached by the SIA. Metrics evaluating the added value of an SIA can help to inform the design of vaccination strategies to better reach zero-dose or undervaccinated children.
Chemical characterization of PM
2.5
organic carbon, elemental carbon, water soluble inorganic ionic components, and major and trace elements was carried out for a source apportionment study of PM
2.5
...at an urban site of Delhi, India from January, 2013, to December, 2014. The annual average mass concentration of PM
2.5
was 122 ± 94.1 µg m
−3
. Strong seasonal variation was observed in PM
2.5
mass concentration and its chemical composition with maxima during winter and minima during monsoon. A receptor model, positive matrix factorization (PMF) was applied for source apportionment of PM
2.5
mass concentration. The PMF model resolved the major sources of PM
2.5
as secondary aerosols (21.3 %), followed by soil dust (20.5 %), vehicle emissions (19.7 %), biomass burning (14.3 %), fossil fuel combustion (13.7 %), industrial emissions (6.2 %) and sea salt (4.3 %).
•Ba1-xLa2x/3TiO3 ceramics have been prepared using standard SSR route.•Compositionally induced structural transition at 6% La substitution.•Onset of relaxor behavior traced at 8% La substituted ...composition.•Presence of shallow defects showed blue luminescence.•Optical band gap reduced with La concentration.
Ba1−xLa2x/3TiO3 (0.00⩽x⩽0.10, in a step of 0.02) ceramics have been prepared through solid state reaction route. Structural studies suggested a transition in phase from tetragonal to cubic symmetry with increase in Lanthanum content. Rietveld Refinement technique employed for investigation confirmed the same. Photoluminescence study revealed introduction of structural disorder by means of A-site vacancies and displacement of M–O bond leading to shallow defects. Optical band gap value calculated from UV–Vis spectra decreased with increase in La concentration. A drastic decrease in grain size of undoped BT was observed with introduction of La through Scanning Electron Micrographs. Dielectric studies were performed and a gradual decrease in the Curie temperature with increase in La content in coherence with structural studies was observed along with pinching effect. Normal ferroelectric character was obtained for the composition x=0.00 to x=0.06 while relaxor like behavior was observed for composition x⩾0.08. The composition x=0.10 made a good Vogel–Fulcher fit. Inhomogeneity induced in the BT lattice due to 8% La doping is strong enough to make an onset of such behavior. P∼E hysteresis loop showed a regular decrease in remnant polarization and coercive field featuring similar relaxor like behavior.
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