Browsing by Author "R. Upadhyay"

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Alpha-induced reactions on gold
(1988) N.L. Singh; A.V. Mohan Rao; S. Mukherjee; R. Upadhyay; R.K. Jain; S.K. Bose; L. Chaturvedi; J. Rama Rao
The excitation functions of the 197Au(( alpha ,n), ( alpha ,2n), ( alpha ,3n), (d,2pn), ( alpha , alpha n) and ( alpha , alpha 3n)) reactions were measured up to 75 MeV. The experimental data were compared with the calculated values obtained by means of a hybrid model (ALICE/85/300) using the initial exciton number n0=4(4p0h) and the level density parameters a=A/8. A general agreement was found for all except the ( alpha , alpha n) and ( alpha , alpha 3n) reactions, where the disagreement was by about two orders of magnitude.
Excitation functions of alpha particle induced reactions in cobalt in the energy range 10-120 MeV using variable energy cyclotrons
(1987) J.Rama Rao; A.V.Mohan Rao; S. Mukherjee; R. Upadhyay; N.L. Singh; S. Agarwal; L. Chaturvedi; P.P. Singh
Alpha particle induced reactions on the target element cobalt were investigated from 10 to 120 MeV, using foil stack activation technique and the Ge(Li) gamma ray spectroscopy method. Ten excitation functions for reaction residues 51Cr, 52,54Mn, 56,57Ni, 59Fe and 56,57,58,60Co were measured, of which 59Co(α, p6n)56Ni reaction was measured for the first time. A comparison with pre-equilibrium hybrid model was made using initial exciton number, n0 = 4 (4pOh). It is observed that for (α, xnypzα) type reactions the agreement is within a factor of 2, while for (α, xnyp) type the disagreement is generally by more than an order of magnitude. © 1987.
Non-equilibrium effects in alpha-particle-induced reactions in light, medium and heavy nuclei up to 120 mev
(1987) J. Rama Rao; A.V. Mohan Rao; S. Mukherjee; R. Upadhyay; N.L. Singh; S. Agarwal; L. Chaturvedi; P.P. Singh
Alpha-particle-induced reactions on the target elements vanadium, niobium and holmium were investigated in the energy range from 10 to 120 MeV, using the foil stack activation technique and Ge(Li) gamma-ray spectroscopy. The excitation functions of six reactions of the (alpha, xn) type were studied, of which three reactions 51V(alpha, n)54Mn, 165Ho(alpha ,2n)167Tm and 165Ho(alpha ,4n)165Tm were measured for the first time in the energy range from 80 to 120 MeV. A preliminary theoretical comparison with the pre-equilibrium hybrid model was made using an initial exciton number of n0=4 (4p0h) and general agreement was found for all except the 51V(alpha , n) and 93Nb(alpha , n) reactions at high energies. © 1987 IOP Publishing Ltd.
Pre-equilibrium effects in the formation of meta stable states
(1994) R. Upadhyay; Ch V Sastry; R.K. Jain; J Rama Rao
Isomeric yield ratios have been measured for93Nb(α, 2 n)95 m,gTc reaction in the energy range 25–60 MeV. The ratios were compared with theoretical values obtained by means of two models one based on compound nucleus mechanism only and the other including pre-equilibrium effects. The trend of experimental ratios is better reproduced by the latter model, although there remains some discrepancy as to the magnitude at higher energies. © 1994, Indian Academy of Sciences. All rights reserved.
Role of secondary metabolites in plant defense mechanisms: a molecular and biotechnological insights
(Springer Science and Business Media B.V., 2024) R. Upadhyay; R. Saini; P.K. Shukla; K.N. Tiwari
The plants produce secondary metabolites (SMs) as defence compounds against both abiotic and biotic stresses. These stresses instigate the secretion and release of SMs by up or down-regulating the concerned genes involved in their synthesis. The secretion of SMs varies with the plant's genetic constitution and accordingly-they are susceptible or resistant. These metabolites mostly act as deterrents or antifeedants, allelochemicals, toxins or precursors of other metabolites that defend plants from stresses. However, some pathogens use these metabolites as a signal for host recognition or nutrition rather than using them as toxins or deterrents. The SMs activate different signalling pathways e.g. terpenoids modulate the calcineurin pathway, sesquiterpenoids modulate the jasmonic acid and salicylic acid pathway, polyphenols activate the jasmonic acid and phenylpropanoid pathway, and alkaloids activate the salicylic acid pathway to protect against pathogens and herbivores. Polyphenolic compounds provide resistance to different microbes by expressing different pathogenesis-proteins and hypersensitive reaction-mediated cell death and eliminate pathogens by altering the membrane permeability (inhibiting efflux pump), cell wall integrity, suppressing enzyme activity, free radicals’ generation, inhibiting protein biosynthesis, damaging DNA and reducing the expression of virulent genes. Flavonoids help plants sustain pathogen stresses through the changes in the auxin transport process. The pathogen exposure upregulate genes of alkaloid synthesis pathways such as tyrosine decarboxylase (TyDC), S-norcoclurine synthase (NCS), codeinone reductase 2-like (COR-2), and StWRKY8 transcription factors which in turn accumulate alkaloids in large amounts. Plant exposure to pathogens leads to hypersensitivity reactions and phytoalexin accumulation. The plant's treatment of salicylic acid and jasmonic acid upregulated downstream transcription factors, increased the expression of defence proteins, triggered the synthesis of SMs, and provided resistance against multiple pathogens. Pathogens and herbivores have also coevolved to cope with defence metabolites by detoxifying the toxic metabolites, converting toxins into useful products, evolving their food choice, fast digestive system, expulsion of toxins, and down-regulation of the gene-producing secondary metabolites. This review article gives a molecular insight into the genes and regulatory proteins controlling the synthesis of SMs, which may help decipher the role of the biosynthetic pathway intermediates and thereby scoring genes providing resistance to various stresses. The article comprehensively describes the roles of different SMs in plant defence and their molecular mechanisms of action. © The Author(s), under exclusive licence to Springer Nature B.V. 2024.
Vaccination saves lives: a real-time study of patients with chronic diseases and severe COVID-19 infection
(Oxford University Press, 2023) A. Mukherjee; G. Kumar; A. Turuk; A. Bhalla; T.C. Bingi; P. Bhardwaj; T.D. Baruah; S. Mukherjee; A. Talukdar; Y. Ray; M. John; J.R. Khambholja; A.H. Patel; S. Bhuniya; R. Joshi; G.R. Menon; D. Sahu; V.V. Rao; B. Bhargava; S. Panda; P. Mishra; Y. Panchal; L.K. Sharma; A. Agarwal; G.D. Puri; V. Suri; K. Singla; R. Mesipogu; V.S. Aedula; M.A. Mohiuddin; D. Kumar; S. Saurabh; S. Misra; P.K. Kannauje; A. Kumar; A. Shukla; A. Pal; S. Chakraborty; M. Dutta; T. Mondal; S. Chakravorty; B. Bhattacharjee; S.R. Paul; D. Majumder; S. Chatterjee; A. Abraham; D. Varghese; M. Thomas; N. Shah; M. Patel; S. Madan; A. Desai; M.L. Kala Yadhav; R. Madhumathi; G.S. Chetna; U.K. Ojha; R.R. Jha; A. Kumar; A. Pathak; A. Sharma; M. Purohit; L. Sarangi; M. Rath; A.D. Shah; L. Kumar; P. Patel; N. Dulhani; S. Dube; J. Shrivastava; A. Mittal; L. Patnaik; J.P. Sahoo; S. Sharma; V.K. Katyal; A. Katyal; N. Yadav; R. Upadhyay; S. Srivastava; A. Srivastava; N.N. Suthar; N.M. Shah; K. Rajvansh; H. Purohit; P.R. Mohapatra; M.K. Panigrahi; S. Saigal; A. Khurana; M. Panchal; M. Anderpa; D. Patel; V. Salgar; S. Algur; R. Choudhury; M. Rao; D. Nithya; B.K. Gupta; B. Kumar; J. Gupta; S. Bhandari; A. Agrawal; M. Shameem; N. Fatima; S. Pala; V. Nongpiur; S. Chatterji; S. Mukherjee; S.K. Shivnitwar; S. Tripathy; P. Lokhande; H. Dandu; A. Gupta; V. Kumar; N. Sharma; R. Vohra; A. Paliwal; M. Pavan Kumar; A. Bikshapathi Rao; N. Kikon; R. Kikon; K. Manohar; Y. Sathyanarayana Raju; A. Madharia; J. Chakravarty; M. Chaubey; R.K. Bandaru; M. Ali Mirza; S. Kataria; P. Sharma; S. Ghosh; A. Hazra
Objectives: This study aims to describe the demographic and clinical profile and ascertain the determinants of outcome among hospitalized coronavirus disease 2019 (COVID-19) adult patients enrolled in the National Clinical Registry for COVID-19 (NCRC). Methods: NCRC is an on-going data collection platform operational in 42 hospitals across India. Data of hospitalized COVID-19 patients enrolled in NCRC between 1st September 2020 to 26th October 2021 were examined. Results: Analysis of 29 509 hospitalized, adult COVID-19 patients [mean (SD) age: 51.1 (16.2) year; male: 18 752 (63.6%)] showed that 15 678 (53.1%) had at least one comorbidity. Among 25 715 (87.1%) symptomatic patients, fever was the commonest symptom (72.3%) followed by shortness of breath (48.9%) and dry cough (45.5%). In-hospital mortality was 14.5% (n = 3957). Adjusted odds of dying were significantly higher in age group ≥60 years, males, with diabetes, chronic kidney diseases, chronic liver disease, malignancy and tuberculosis, presenting with dyspnoea and neurological symptoms. WHO ordinal scale 4 or above at admission carried the highest odds of dying [5.6 (95% CI: 4.6–7.0)]. Patients receiving one [OR: 0.5 (95% CI: 0.4–0.7)] or two doses of anti-SARS CoV-2 vaccine [OR: 0.4 (95% CI: 0.3–0.7)] were protected from in-hospital mortality. Conclusions: WHO ordinal scale at admission is the most important independent predictor for in-hospital death in COVID-19 patients. Anti-SARS-CoV2 vaccination provides significant protection against mortality. © The Author(s) 2022.