Browsing by Author "Pratibha Singh"

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An improved and facile synthesis of schiff bases in aqueous medium
(2005) M.S. Singh; A.K. Singh; Pratibha Singh; Ruchi Jain
[No abstract available]
An introduction of parthenium hysterophorus to be boon for agricultural land: Under heavy metal contamination
(Plant Archives, 2020) Madhulika Singh; Pratibha Singh; Rajiv Kumar Singh; Pankaj Kumar Singh; Sheo Mohan Prasad; Aparna Pandey
Recently, the contamination of agricultural land possesses major threats to human health and the environment. The catastrophic events comprising geologic activities and anthropogenic activities leave every year a huge amount of nutrient/metal ions in agricultural land/water bodies, they remain in soil for many years and are the potential cause of phytotoxicity or poisoning of the food chain. Generally metal ions are essential in trace amount for the normal development of animals and plants but become toxic when accumulated at higher concentrations. Among the number of practices, phytoremediation was initially proposed as an environmental cleanup technology for the remediation of metal contaminated land. © 2020 Plant Archives. All rights reserved.
Application of soil amendments mitigates phytotoxic effects on Solanum melongena L. and Lycopersicon esculentum L. seedlings exposed to chlorpyrifos and dimethoate pesticides
(Springer Science and Business Media Deutschland GmbH, 2023) Pratibha Singh; Madhulika Singh; Sunita Kumari Singh; Sheo Mohan Prasad
This field study was done to study the effects of pesticides chlorpyrifos and dimethoate singly and in combination with soil amendments like chemical fertilizer (CF), farmyard manure (FM), and 50% CF + 50% FM (CM) on various indices of growth, physio-biochemical parameters of brinjal, and their residual effect in tomato seedlings. As compared to the control, the decrease of 9.5 and 5.5%, 8.9 and 5.0% in fresh weight, dry weight respectively was recorded in the pesticide-only treatment in the brinjal crop. Pesticides when applied in combination with soil amendments depicted the highest growth of 105.4 and 118.2%, 104.1 and 115.1% in pesticides + CF treatment, 72.7 and 85.1%, 68.1 and 78.1% in pesticides + CM treatment, and 64.4 and 74.0%, 62.7 and 65.7% in pesticides + FM treatment compared to control. In tomato seedlings, the pesticides + CF treatment exhibited the lowest growth indices (25.5 and 31.9%, 26.4 and 28.8%) across the combined treatments while pesticide-only treatment depicted minimum growth compared to the control. In the case of photosynthesis rate and antioxidant activity, the combined treatments showed the trend as pesticides + CF > pesticides + CM > pesticides + FM in the brinjal crop; however, the trend became somewhat reversed in the tomato crop. The results indicated that soil-amended practices modulated pesticide-induced damage by upregulating photosynthetic performance, chlorophyll a fluorescence, and antioxidant balancing which might be associated with the mitigation of ROS-induced pesticide toxicity, and the effect was more pronounced with CM. Furthermore, our study was supported by non-metric-multidimensional scaling (NMDS)-constructed ordination plots by showing spatial patterns in different variables. The study might help in taking management decision to design mitigation actions for government and non-government agency at the farmers’ level. © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
Characterisation of islet antibody-negative type 1 diabetes mellitus in Indian children
(John Wiley and Sons Inc, 2025) Jayakrishnan C. Menon; Pratibha Singh; Archana Archana; Uma Kanga; Preeti Lata Singh; Medha Mittal; Atul Garg; Anju Seth; Vijayalakshmi Bhatia; Preeti Dabadghao; Siddhnath Sudhanshu; Ruchira Vishwakarma; Shivendra Verma; Shipra Kumar Singh; Eesh Bhatia
Aims: Islet antibody-negative type 1 diabetes mellitus (T1DM) has not been well characterised. We determined the frequency of antibody-negative T1DM and compared it with antibody-positive T1DM in a cohort of north Indian children. Methods: In a multi-centre, prospective, observational study, 176 Indian children (age 1–18 years) were assessed within 2 weeks of diagnosis of T1DM. Antibodies against GAD65 (GADA), islet antigen-2 (IA-2A) and zinc transporter 8 (ZnT8A), were estimated using validated ELISA. HLA-DRB1, DQA1 and DQB1 alleles were studied by Luminex-based typing. Monogenic diabetes was determined by targeted next-generation sequencing using the Illumina platform. Results: After excluding 12 children with monogenic diabetes, GADA, IA-2A and ZnT8A were present in 124 (76%), 60 (37%) and 62 (38%) children, respectively, while 24 (15%) were negative for all antibodies. A single antibody (most frequently GADA) was present in 68 (41%) of children, while all three antibodies were found in 34 (21%). Islet antibody-negative T1DM (n = 24, 15%) did not differ from antibody-positive children in their clinical features, HbA1c or plasma C-peptide, both at onset or after 1 year follow-up (available in 62 children). The frequency of other organ-specific antibodies or high-risk HLA-DR and DQ alleles were also similar. Children with a single islet antibody did not differ from those with multiple antibodies. Conclusions: The frequency of various islet-antibodies, in isolation and combination, differed considerably from studies among children of European descent with T1DM. Children with T1DM who were islet antibody-negative were indistinguishable from those who were antibody-positive. © 2024 Diabetes UK.
Characterisation of islet antibody-negative type 1 diabetes mellitus in Indian children
(John Wiley and Sons Inc, 2024) Jayakrishnan C. Menon; Pratibha Singh; Archana Archana; Uma Kanga; Preeti Singh; Medha Mittal; Atul Garg; Anju Seth; Vijayalakshmi Bhatia; Preeti Dabadghao; Siddhnath Sudhanshu; Ruchira Vishwakarma; Shivendra Verma; S.K. Singh; Eesh Bhatia
Aims: Islet antibody-negative type 1 diabetes mellitus (T1DM) has not been well characterised. We determined the frequency of antibody-negative T1DM and compared it with antibody-positive T1DM in a cohort of north Indian children. Methods: In a multi-centre, prospective, observational study, 176 Indian children (age 1–18 years) were assessed within 2 weeks of diagnosis of T1DM. Antibodies against GAD65 (GADA), islet antigen-2 (IA-2A) and zinc transporter 8 (ZnT8A), were estimated using validated ELISA. HLA-DRB1, DQA1 and DQB1 alleles were studied by Luminex-based typing. Monogenic diabetes was determined by targeted next-generation sequencing using the Illumina platform. Results: After excluding 12 children with monogenic diabetes, GADA, IA-2A and ZnT8A were present in 124 (76%), 60 (37%) and 62 (38%) o children, respectively, while 24 (15%) were negative for all antibodies. A single antibody (most frequently GADA) was present in 68 (41%) of children, while all three antibodies were found in 34 (21%). Islet antibody-negative T1DM (n = 24, 15%) did not differ from antibody-positive children in their clinical features, HbA1c or plasma C-peptide, both at onset or after 1 year follow-up (available in 62 children). The frequency of other organ-specific antibodies or high-risk HLA-DR and DQ alleles were also similar. Children with a single islet antibody did not differ from those with multiple antibodies. Conclusions: The frequency of various islet-antibodies, in isolation and combination, differed considerably from studies among children of European descent with T1DM. Children with T1DM who were islet antibody-negative were indistinguishable from those who were antibody-positive. © 2024 Diabetes UK.
Climate Change Impacts on Agriculture: Crop Productivity and Food Security
(CRC Press, 2023) Pratibha Singh; Shivani Singh; Rama Shanker Dubey
Climate change adversely affects agricultural productivity and food security across the world. Global warming due to increased greenhouse gases, increasing temperatures, has resulted in extremes of weather conditions, changing patterns of rainfall, flooding, heat wave, shortage of irrigation water, drought, salinity, loss of soil fertility, emergence of new pests and diseases, etc., which have adversely affected quantity and quality of food grain production. During the last 80 years, a consistent and substantial decline in the yield of major food and oil crops have been seen due to global warming. Climate change affects nutritional quality of foods, availability of nutrients within a food supply chain, and hence food security remains a great challenge due to climate change. To feed increasing global population strategies need to be adopted for sustainable production of foods. Climate-smart sustainable farming practices and improved technologies are needed to sustainably enhance agricultural productivity and to attain food security. © 2023 selection and editorial matter, M. H. Fulekar and Rama Shanker Dubey; individual chapters, the contributors.
Comparative Evaluation of Cadmium Toxicity Effects on Growth, Photosynthetic and Oxidative Stress Parameters in Various Genotypes of Indica Rice (Oryza Sativa L.) Seedlings
(Indian Society of Agricultural Biochemists, 2022) Shivani Singh; Pratibha Singh; Rama Shanker Dubey
In hydroponics, experiments were performed to examine plant growth, oxidative stress parameters, and level of photosynthetic pigments in nine rice (Oryza sativa L.) genotypes collected from different locations in India, grown under 50 µM and 100 µM cadmium nitrate application. In all the rice genotypes, with an increase in Cd concentration in the growth medium, root and shoot growth as well as levels of Chl a, Chl b and carotenoids declined significantly compared to untreated seedlings. A significant elevation in the levels of H2O2 and lipid peroxidation was observed in the seedlings due to Cd treatment. The upland varieties of rice Sobhagi, Vandana and IDR-763 showed better growth performance, lesser H2O2 production and lesser oxidative damage due to Cd, compared to inland varieties. Results suggest that the rice cultivars Sobhagi, Vandana and IDR-763 appeared to be fairly tolerant to high Cd levels. © 2022, Indian Society of Agricultural Biochemists. All rights reserved.
Crop Plants Develop Extracellular Signaling Products Against Salt Stress
(wiley, 2021) Santwana Tiwari; Nidhi Verma; Shikha Singh; Shivam Gupta; Madhulika Singh; Pratibha Singh; Jitendra Pandey; Sheo Mohan Prasad
Plant signaling is a usual phenomenon that facilitates the transduction of external and internal signals into physiological reactions such as modification of activity of various enzymes, cytoskeleton structure, and gene expression. This chapter aims to gather all the information about extracellular products secreted by crop plants as well as cyanobacteria with their working mechanisms under salt stress conditions and their role in economic values in agriculture and medicine. The biosynthesis of bioactive extracellular compounds in plants aimed to enhance crop tolerance to abiotic and biotic stresses and overcome stressful conditions. The level of antioxidants, enzymes, and proteins has fluctuated under salt stress. Salt stress often generates both ionic and osmotic stress in plants, resulting in a greater disturbance in signaling and accumulation or decrease of specific metabolites in plants. In agriculture, cyanobacterial and plant's secondary metabolites are key tools for enhancing crop production. © 2022 John Wiley & Sons Ltd. All rights reserved.
Designing hydroxy-functionalized chiral salen ligand and its use in the synthesis of dioxadiazasilamacroheterocycles
(2010) M.S. Singh; Pratibha Singh; Ashutosh Gupta
Synthesis of dioxadiazasilamacroheterocycles is described. The key step involves the initial synthesis of symmetrical hydroxyl-functionalized chiral salen ligand, N, N-bis(2- hy droxy acetophenony lidene)-1, 2-diaminocy clohexane followed by sequential deprotonation with NaH to form dianion intermediate in situ, which reacts with diorganodichlorosilanes to furnish desired heterocycles. The products have been characterized by satisfactory elemental analyses and spectral (IR, 1H 13C, 29Si NMR and mass) studies.
Development of ultra performance liquid chromatography tandem mass spectrometry method for simultaneous identification and quantitation of potential osteogenic phytochemicals in butea monosperma
(Oxford University Press, 2018) Vikas Bajpai; Awantika Singh; Pratibha Singh; Khushbu Sharma; Bikarma Singh; Bhim Pratap Singh; Mahendra Sahai; Rakesh Maurya; Brijesh Kumar
An ultra performance liquid chromatography coupled with hybrid triple-quadrupole linear ion trap tandem mass spectrometry (UPLC-ESI-QqQLIT-MS-MS) method in multiple reaction monitoring mode was developed for identification and simultaneous determination of potential osteogenic compounds in ethanol extracts of different plant parts of Butea monosperma collected from different geographical regions. The chromatographic separation was carried out on an Acquity UPLC CSH C18 column (1.7 μm, 2.1 × 100 mm) with 0.1% (v/v) formic acid in water and methanol as mobile phase under gradient conditions in 8 min. The developed method was validated according to the guidelines of international conference on harmonization. The correlation coefficients of all the calibration curves were ≥0.9995 and recoveries ranged from 95.2 to 105.8% (RSD ≤ 1.95%). Relative standard deviations of intra-day, inter-day precisions and stability were ≤1.74, 1.84 and 2.8%, respectively. The quantitative results showed remarkable differences in the content of all potential osteogenic compounds in different parts of the plant as well as samples from different geographical regions. Quantitative variations studied from principal component analysis indicated tentative markers for B. monosperma cultivars which can discriminate sample of different geographical regions. © The Author(s) 2018. Published by Oxford University Press. All rights reserved.
Dianion cyclization strategy for the synthesis of macrosilaheterocycles
(2008) Maya S. Singh; Pratibha Singh
A practical and efficient method for the preparation of silaheterocycles is described. The key step involves the initial formation of symmetrical chiral ditopic ligand, N,N′-1,2-cyclohexylenebis(salicylideneimine) followed by sequential deprotonation with NaH to form dianion intermediate, which reacts with diorganodichlorosilanes to furnish dibenzodioxadiazasilamacrocycles. The products were characterized by satisfactory elemental analyses and spectral (IR, 1H, 13C, 29Si NMR, and Mass) studies. © 2008 Wiley Periodicals, Inc.
Exploring variability and genetic diversity among rice genotypes in Eastern Uttar Pradesh
(Indian Society of Plant Breeders, 2022) Pratibha Singh; S.K. Singh; Mounika Korada; Amrutlal Khaire; D.K. Singh; Sonali Vijay Habde; Prasanta Kumar Majhi; Rudresha Naik
The genetic improvement of any crop mainly depends on the amount of genetic variability present in the population.To explore this variability, an effort was made to classify, understand the nature and magnitude of genetic variabilityand diversity among 112 rice genotypes for 16 quantitative traits using Mahalanobis D2 statistics. Analysis of variancerevealed a wide and significant variation for all the 16 traits studied. A slight difference between PCV and GCV wasfound, suggesting that genetic control of traits is higher than environmental influence. Characters such as harvestindex, days to first flowering, days to 50% flowering, and plant height showed high heritability coupled with high geneticadvance as per cent of mean suggesting that selection for the improvement of these traits may be rewarding. Clusteranalysis indicated that the 112 rice genotypes were grouped into 7 clusters, wherein cluster I had the highest numberof genotypes (73) followed by cluster III with 22 genotypes. The maximum inter-cluster distance was recorded betweenclusters V and VII with a D2 value of 58981.07, followed by clusters II and V (51875.13). The number of spikelets perpanicle (52.17%) and the number of grains per panicle (27.26%) were found to be the most contributing traits towardstotal genetic diversity. Hence, information on the nature and degree of divergence would help the plant breeder in theselection and hybridization procedure for choosing the right type of parents to improve yield and other traits © 2022. Electronic Journal of Plant Breeding. All Rights Reserved.
Facile one pot synthesis of dioxazadibenzocyclodecene-6-one, 6-thione and other homologues
(Arkat, 2009) M.S. Singh; Pratibha Singh; Pallavi Singh; Ashutosh Gupta
Previously unknown dioxazadibenzocyclodecene-6-one, -6-thione and other homologues were prepared via the intermediacy of a 1,9-dianion generated and used in situ from N-(2-hydroxymethylphenyl)salicylideneimine followed by treatment with a variety of dielectrophiles in a simple one-pot procedure. The products were characterized by satisfactory elemental analyses and spectral (IR,1H,13C NMR and Mass) studies.
Ferrous Chloride and Sodium Ascorbate Alleviate Pb Toxicity in Rice Seedlings my Modulating the Activity of Antioxidative Enzymes
(Indian Society of Agricultural Biochemists, 2021) Pratibha Singh; Shivani Singh; Rama Shanker Dubey
When seedlings of an Indica rice cultivar HUR-105 were raised for 8 days in hydroponics in Yoshida nutrient solution containing 800 μM Pb(NO3)2, it was observed that Pb treatment caused reduction in height and fresh weight, and increase in the activity of antioxidative enzymes such as superoxide dismutase, catalase and ascorbate peroxidase. The reduction in height and fresh weight was greater with increase in Pb treatment duration. Pb treated seedlings showed the elevated level of antioxidative enzymes activity at 8th day as compared to 4th day in the roots and shoots of the seedlings. When FeCl2 and sodium ascorbate were added in Pb containing growth medium, a noticeable alleviation of Pb toxicity was seen in correlation to growth parameters and antioxidative enzymes activity in both roots and shoots of rice seedlings. Results suggest that both FeCl2 and sodium ascorbate have high potential to alleviate Pb toxicity in rice seedlings. © 2021, Indian Society of Agricultural Biochemists. All rights reserved.
High Frequency of Recessive WFS1 Mutations Among Indian Children With Islet Antibody-negative Type 1 Diabetes
(Endocrine Society, 2024) Jayakrishnan C Menon; Pratibha Singh; Archana Archana; Preeti Singh; Medha Mittal; Uma Kanga; Kausik Mandal; Anju Seth; Vijayalakshmi Bhatia; Preeti Dabadghao; Siddhnath Sudhanshu; Atul Garg; Ruchira Vishwakarma; Aditya Narayan Sarangi; Shivendra Verma; Surya Kumar Singh; Eesh Bhatia
Background: While the frequency of islet antibody-negative (idiopathic) type 1 diabetes mellitus (T1DM) is reported to be increased in Indian children, its aetiology has not been studied. We investigated the role of monogenic diabetes in the causation of islet antibody-negative T1DM. Methods: We conducted a multicenter, prospective, observational study of 169 Indian children (age 1-18 years) with recent-onset T1DM. All were tested for antibodies against GAD65, islet antigen-2, and zinc transporter 8 using validated ELISA. Thirty-four islet antibody-negative children underwent targeted next-generation sequencing for 31 genes implicated in monogenic diabetes using the Illumina platform. All mutations were confirmed by Sanger sequencing. Results: Thirty-five (21%) children were negative for all islet antibodies. Twelve patients (7% of entire cohort, 34% of patients with islet antibody-negative T1DM) were detected to have pathogenic or likely pathogenic genetic variants. The most frequently affected locus was WFS1, with 9 patients (5% of entire cohort, 26% of islet antibody-negative). These included 7 children with homozygous and 1 patient each with a compound heterozygous and heterozygous mutation. Children with Wolfram syndrome 1 (WS) presented with severe insulin-requiring diabetes (including 3 patients with ketoacidosis), but other syndromic manifestations were not detected. In 3 patients, heterozygous mutations in HNF4A, ABCC8, and PTF1A loci were detected. Conclusion: Nearly one-quarter of Indian children with islet antibody-negative T1DM had recessive mutations in the WFS1 gene. These patients did not exhibit other features of WS at the time of diagnosis. Testing for monogenic diabetes, especially WS, should be considered in Indian children with antibody-negative T1DM. © 2023 The Author(s). Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved.
Hindi language text search: A literature review
(National Institute of Science Communication and Information Resources (NISCAIR), 2017) Pratibha Singh; Aditya Tripathi
The literature review focuses on the major problems of Hindi text searching over the web. The review reveals the availability of a number of techniques and search engines that have been developed to facilitate Hindi text searching. Among many problems, a dominant one is when a text formed by combinatorial characters or words is searched. © 2017, National Institute of Science Communication and Information Resources (NISCAIR). All rights reserved.
Influence of herbicide and soil amendments on soil nitrogen dynamics, microbial biomass, and crop yield in tropical dryland agroecosystems
(2012) Pratibha Singh; R.P. Singh; Nandita Ghoshal
Nitrogen (N) dynamics is the key factor for designing management strategies to achieve sustained crop productivity. A 2-yr field experiment was performed to examine the influence of herbicide (butachlor [2-chloro 2′6′ diethyl-n-butoxy-methylacetanilide]; HC) alone or in combination with soil amendments on N dynamics involving N mineralization rate (Nmin), inorganic N pool, N uptake (Nup) by plants, soil microbial biomass N, and crop yield in tropical dryland agroecosystems. The Nmin rate showed distinct seasonal patterns which decreased from rice period to summer fallow except herbicide + animal manure (farmyard manure; HC + AM) and herbicide + crop residue (wheat [Triticum aestivum L.] straw; HC + CR) treatments.The annual rate of Nmin, inorganic N pool, and crop yield were higher in HC + AM, herbicide + chemical fertilizer (NPK; HC + CF), herbicide + green manure {dhaincha [Sesbania aculeata (Willd.) Pers.] shoots; HC + GM} while comparable in HC + CR and HC treatments relative to control (CO). Soil moisture content better predicted variation in Nmin rate compared to soil temperature. Plant Nup and crop yield relative to CO was higher in HC + CF, HC + GM, and HC + AM, comparable in HC + CR while lower in the HC treatment. Annual Nmin rate explained a significant part of variations in annual soil microbial biomass N, inorganic N pool, plant Nup, and crop yield. Results indicate that combined application of HC + AM result in relatively sustained availability of inorganic N and higher crop yield throughout the annual cycle. © Soil Science Society of America.
Multicomponent reactions (MCRs) leading to silaheterocycles via dianion cyclization
(2007) M.S. Singh; Pratibha Singh
Nucleophilic asymmetrical Schiff base that incorporating aromatic rings to induce rigidity to the system was prepared by the condensation of o-hydroxyacetophenone and salicylaldehyde hydrazone in a 1:1 molar ratio. A useful sequence of reactions for the synthesis of a variety of previously unknown silaheterocycles is described. The reaction of salicylidene o-hydroxyacetophenone with sodium hydride in dioxane produces a 1,10-remote dianion. The cyclization of this dianion with diorganodichlorosilanes affords dibenzodioxadiazasilaundecines in good yields. The products were characterized by satisfactory elemental analyses and spectral (IR, 1H, 13C, 29SiNMR, andmass) studies. Copyright © Taylor & Francis Group, LLC.
New tandem reactions for the construction of heterocycles via dianion strategy
(2008) M.S. Singh; Pratibha Singh; Pallavi Singh
The reaction of chiral and achiral salen ditopic ligands with sodium in dry isopropanol generates remote O,O-dianions. The dianions thus generated in situ are trapped by suitable phosphorus dielectrophiles to yield 2-oxo and 2-thioxo-1,3,7-dioxazaphos-phadecines and 2-oxo and 2-thioxo-1,3,7,10- dioxadiazaphos-phatridecines in moderate to good overall yield. The products are characterized by elemental and spectral (1R, 1H. 13C, 31P NMR and Mass) studies. A plausible mechanistic logic and concept utilized in the synthesis have been discussed.
Phenolic constituents of Centella asiatica L. and Andrographis paniculata (Burn, f) Wall, ex Nees
(2009) D.P. Singh; Amar Bahadur; Pratibha Singh; J.S. Singh; U.P. Singh
HPLC analysis of different parts of Centella asiatica L and Andrographis paniculata (Burn, f) Wall, ex Nees revealed the presence of tannic (Rt 2.27 min), gallic (Rt 2.92 mm), caffeic (Rt 3.26 min), vanillic (Rt 3.26 min), ferulic (Rt 3.40 min), chlorogenic (Rt 4.16 min), cinnamic (Rt 4.46 min) and salicylic (Rt 7 35 min) acids in various proportions. Qualitative and quantitative variations in phenolic acid profile of both the plants were observed. While gallic acid was present in all parts of both the plants, its maximum amount was present in the leaves of C asiatica (24.2 μg) and fruits of A paniculata (17.2 μg). Caffeic acid was maximum in leaves of C asiatica and A paniculata (6.2 and 7.4 μg/g fresh wt., respectively). The chlorogenic acid was not found in the parts of C asiatica, however, it was present in the leaves (17.2 μg/g fresh wt.) and fruits (3.6 μug/g fresh wt.) of A. paniculata. Other phenolic acids along with salicylic acid were found in both the plants in varying amounts.