Browsing by Author "Upendra Singh"

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Archaeological and archaeobotanical investigations in Tamsa region of Ganga Plain, Uttar Pradesh, India
(SAGE Publications Ltd, 2025) Anil Kumar Pokharia; Pushp Lata Singh; Ruchita Yadav; Mansi Swaroop; Alka Srivastava; Shalini Sharma; Anoop Kumar; Dipak Shukla; Upendra Singh; Chandrabhushan Gupt; Mohd Afroz; Sanjay Kumar Singh Gahlaud
This study presents the archaeological and archaeobotanical findings based on data recorded during excavations at Khapura, a multicultural site in the Ambedkar Nagar district of Uttar Pradesh, India. The ceramic assemblage and other cultural materials, including structural remains, have revealed four distinct cultural periods, namely pre-Northern Black Polished Ware (NBPW), NBPW, Sunga-Kushana, and Gupta, dating back to 1100–200 bce. The carbonised plant remains recovered from the pre-NBPW and NBPW periods suggest a double-cropping pattern, represented by both winter and summer season crops. The identified field crops are represented by grains and seeds such as Hordeum vulgare (barley), Triticum aestivum (wheat), Oryza sativa (rice), Setaria italica (foxtail millet), Vigna sp. (green/black gram), Macrotyloma uniflorum (horse gram), Luffa sp. (sponge gourd), Linum usitatissimum (linseed). Few weeds and wild taxa, like Ziziphus sp. (jujube), Vicia sp. (common vetch), Chenopodium sp. (goosefoot), Polygonum sp. (smart weed/knot weed), were also identified in the recovered plant assemblage. These plant remains have been discussed and compared with the archaeobotanical data from other neighbouring sites in the region. © The Authors 2025. This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access page (https://us.sagepub.com/en-us/nam/open-access-at-sage).
DQF J-RES NMR: Suppressing the singlet signals for improving the J-RES spectra from complex mixtures
(Academic Press Inc., 2019) Upendra Singh; Bikash Baishya
Two-dimensional J-RESolved spectroscopy (J-RES) finds routine use in metabolomics for reducing signal overlap as it separates chemical shift and multiplet information along two frequency axes. However, only magnitude mode of the experiment is practical which prevents exploitation of its full resolving power. Tailing from high-intensity metabolite peaks often obscure nearby low-intensity metabolite peaks which leads to ambiguity in assignment of metabolites. Absorptive mode J-RES spectroscopy offers better-resolving power but comes at the cost of either sensitivity or complicated post-processing. Quite often for certain complex mixtures such as bio-fluids some components of the mixture display intense singlet signals which dominate the whole spectrum resulting in less reliable detection of weaker metabolite signals. Multi-frequency presaturation could suppress these intense singlets but will also remove the useful weaker multiplet peaks which are either totally eclipsed with the intense singlets or very close in frequency. We show that by using a double quantum filter (DQF) in magnitude mode J-RES technique, the intensity of the strong singlet metabolite peaks can be reduced relative to the intensity of the sparsely present multiplet metabolite signals. This approach leads to the identification of many weak intensity multiplet peaks which are otherwise undetected due to their overlap with intense singlet peaks in regular J-RES as well as 1D 1 H spectra. Although the improved intensity of most of the weaker peaks relative to the strong singlet peaks is observed, some multiplets can disappear due to the delay-dependent modulation of the signals by the DQF. A few DQF J-RES spectra recorded with different DQF delays, therefore, produce better assignment when analyzed together. The technique is demonstrated on a mixture of eight compounds, human urine, and plant extract samples. © 2019 Elsevier Inc.
Parallel acquisition of slice-selective 1H-1H soft COSY spectra
(Academic Press Inc., 2017) Upendra Singh; Ajay Verma; Bikash Baishya
A method is demonstrated for parallel acquisition of several slice selective soft COSY proton spectra. Application of a slice selective mixing pulse in a selective correlation experiment allows slice selective coherence transfer between different coupled spin pairs. During such slice selective coherence transfer, the spin states of the passive spins are undisturbed. In other words, slice selective coherence transfer executes spin-state selective coherence transfer between a given spin and all its coupled neighbours. This results in a final spectrum which contains multiple soft cosy spectra between a given signal(s) and all its coupled signals, significantly reducing experimental time. This provides access to all the couplings for a given proton site and its coupled partners. © 2017 Elsevier Inc.
Physicochemical and bioactive constituents, microbial counts, and color components of spray-dried Syzygium cumini L. pulp powder stored in different packaging materials under two controlled environmental conditions
(Frontiers Media SA, 2023) Vishal Kumar; Chandra Shekhar Singh; Shiva Bakshi; Sudhir Kumar; Satya Prakash Yadav; Zakarya Ali Saleh Al-Zamani; Pankaj Kumar; Upendra Singh; Kamlesh Kumar Meena; Durga Shankar Bunkar; Vinod Kumar Paswan
Currently, the demand for functional food items that impart health benefits has been rising. Blackberry (Syzygium cumini L.) fruit has high anthocyanin content and other functional attributes. However, this seasonal fruit is highly perishable, and a large proportion of it goes unharvested and wasted worldwide. Spray drying of the fruit pulp can impart improved shelf life, ensuring long-term availability for consumers to exploit its health benefits. The storage quality varies according to the type of packaging material and the storage environment. Therefore, in this study, the shelf life span of the spray-dried Syzygium cumini L. pulp powder (SSCPP) was investigated during 6 months of storage under three types of packaging materials (i.e., polystyrene, metalized polyester, and 4-ply laminates) in a low-temperature environmental (LTE) and at ambient environmental conditions. The physicochemical stability of bioactive principles (TPC and TAC), microbial counts, and color components were analyzed at 0, 2, 4, and 6 months of storage. There was a significant gradual loss of dispersibility and solubility with an increase in flowability, bulk density, and wettability during the entire storage period for all three packaging materials. The TSS, pH, TPC, TAC, and microbial counts decreased in the SSCPP both at ambient and LTE conditions during the study. Among all the packaging materials, the 4-ply laminate was found to be the most appropriate and safe for storage of spray-dried SCPP at LTE conditions. Copyright © 2023 Kumar, Singh, Bakshi, Kumar, Yadav, Al-Zamani, Kumar, Singh, Meena, Bunkar and Paswan.
Pure shift HMQC: Resolution and sensitivity enhancement by bilinear rotation decoupling in the indirect and direct dimensions
(Academic Press Inc., 2020) Upendra Singh; Subrato Bhattacharya; Bikash Baishya
The heteronuclear multiple-quantum coherence in the indirect dimension of the two-dimensional HMQC experiment evolves under the passive 1H-1H J-couplings leading to multiplet structures in the F1 dimension. Besides, 1H-1H J-multiplets appear in the direct dimension as well. Thus, multiplets along both dimensions lower the resolution and sensitivity of this technique, when high resolution is required along both dimensions. An efficient broadband homodecoupling scheme along the F1 dimension of the HMQC experiment has not been realized to date. We have implemented broadband homonuclear decoupling using bilinear rotation decoupling (BIRD) by adding a 1H SQ evolution period followed by BIRD before the 1H-13C multiple-quantum evolution period in the HMQC. In the direct time domain, BIRD is implemented using a real-time or single-scan scheme, which further improves resolution and sensitivity of this technique. The resulting pure shift HMQC provides singlet peak per chemical site along F1 as well as F2 axes and, hence, better resolution and sensitivity than conventional HMQC spectrum for all peaks except diastereotopic methylene protons. Due to the incorporation of the BIRD, the indirect time domain becomes double in length compared to the conventional HMQC. However, slow relaxation of small molecules favors better sensitivity for ps-HMQC relative to conventional HMQC under all conditions. We also found that the sensitivity of ps-HMQC is only slightly less than ps-HSQC for small molecules. © 2020 Elsevier Inc.