Browsing by Author "Ramesh Kumar"

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Adenosine deaminase activity in sera of patients with visceral leishmaniasis in India
(2008) Kiran Tripathi; Ramesh Kumar; Kalpana Bharti; Pramod Kumar; RajKamal Shrivastav; Shyam Sundar; Kalpana Pai
Background: Serum adenosine deaminase (ADA) activity increases in diseases where cellular immunity is involved. Since cell-mediated immune responses play a paramount role in the pathogenesis and healing of the visceral leishmaniasis, therefore, the present study was undertaken to evaluate the serum ADA activity in different pathological conditions. Methods: Adenosine deaminase was determined in sera of active visceral leishmaniasis (VL) patients at diagnosis and at posttreatment (n = 22), healthy controls (n = 15), patients with malaria (n = 10), leprosy (n = 10) and tuberculosis (n = 10). Results: Serum levels of ADA were significantly higher in active VL patients as compared to controls and patients with other diseases. ADA levels were also raised in patients with malaria, though not significantly as compared with active VL patients. Sera from VL patients at posttreatment showed significantly decreased ADA levels over sera from patients at diagnosis. Conclusions: The results therefore suggest that ADA is involved in the pathogenesis and could be used as a clinical marker in the diagnosis of visceral leishmaniasis. © 2007 Elsevier B.V. All rights reserved.
Biopolymer and polymer precursor production by microorganisms: applications and future prospects
(John Wiley and Sons Ltd, 2024) Baljeet Singh Saharan; Neel Kamal; Prerana Badoni; Ramesh Kumar; Mayuri Saini; Dharmender Kumar; Deepansh Sharma; Swati Tyagi; Poonam Ranga; Jagdish Parshad; Chhaya Goyal; Ravinder Kumar; Manju Nehra; Chandra Shekhar Seth; Joginder Singh Duhan; Neelam Kumari Mandal
Polymers have been used in various industries over the past few decades due to their tremendous applications. Among these, polyhydroxyalkanoates and poly(lactic acid) are easily biodegradable biopolymers derived from bacteria, including recombinant Escherichia coli, Alcaligenes eutrophus, Alcaligenes latus, Azotobacter vinelandii, methylotrophs and Pseudomonas. Conventional petroleum-derived polymers have become potentially harmful to the environment due to their complex degradation process. The nonbiodegradability of synthetic polymers has become a global issue of concern. There is an urgent need for a substitute to tackle the increasing environmental stress. Microorganisms are small factories for producing different types of polymers during their growth cycle. Various features like biodegradability, biocompatibility, nontoxicity and wide substrate spectrum make such microbial polymers highly reliable. Biopolymers such as alginate, cellulose, cyanophycin, levan, polyhydroxyalkanoates, xanthan, poly(lactic acid) and poly(γ-glutamic acid) can be obtained from different microorganisms like Aureobasdium pullulans, Acetobacter xylinum, Bacillus thermoamylovorans and Cupriavidusnecator. These are extensively used in various fields like food, medicine, wastewater treatment, biofuel production, packaging and cosmetics. Despite being advantageous in several ways, the biopolymer market still faces several hurdles. This review mainly emphasizes the different types of biopolymers, production by microorganisms and various applications of these biopolymers in different fields. The main drawback limiting the development of these polymers is the high production cost and low efficiency of the microbial strains. Genetic recombination is an efficient technique to enhance the microbial yield and to expand the biopolymer market size. © 2023 Society of Chemical Industry (SCI). © 2023 Society of Chemical Industry (SCI).
Bioremediation of Chromium-contaminated Agricultural Soil Using Alginate-Encapsulated Bacterial Beads
(Springer Nature, 2025) Anjali Srivastava; Asha Lata Singh; Monika Yadav; Mayur B. Kurade; Ramesh Kumar; Moonis Ali Khan; Byong-hun Jeon
In this study, the efficacy of indigenous bacteria present in Cr-contaminated soil was tested for soil decontamination. Potential bacterial strains were screened and selected from soil samples and immobilized on sodium alginate beads. The most effective Cr(VI) reducing strain identified using 16S rRNA genome sequencing was Enterococcus italicus. Bacterial beads of E. italicus were optimized for Cr(VI) reduction under various exploratory conditions, such as temperature, pH, biomass, contact period, and different nutritional sources. Beads containing 1000 mg/g of E. italicus biomass reduced up to 91% of Cr(VI) (from an initial 5.4 mg/g in the soil) at pH 7 and 35 ℃ within 2 h. Glucose was found to be a good source of electron contributors that can reduce up to 94% of Cr(VI). FTIR analysis of the Cr(VI)-treated bacterial beads showed amines, -COO−, -CH3, C–O–C, and PO2 as new functional groups, revealing absorption and reduction of Cr(VI) from contaminated soil. The cell size of E. italicus after Cr-contaminated soil treatment was larger than that of untreated bacterial cells. The elemental analyses of treated and untreated bacterial cells revealed the presence of Cr inside the treated cells of E. italicus, which were transported from the soil during its treatment. Further, the XPS analysis confirmed the reduction of Cr(VI) to Cr(III) in the treated bacterial beads of E. italicus. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.
Dielectric modulated TFET on SELBOX substrate as a label-free biosensor applications: analytical modeling study and sensitivity analysis
(Institute of Physics, 2024) Ashish Kumar Singh; Ramesh Kumar; Satyabrata Jit
The manuscript proposes a ferroelectric heterojunction TFET (BG-FE-HJ-STFET) on SELBOX substrates with a back gate to create an ultra-sensitive label-free biosensor with dielectric modulation for the detection of neutral and charged biomolecules. Within the proposed device, four cavities have been carved out for the biomolecules’ immobilization under the front and rear gate dielectrics. By using a ferroelectric (FE) material as a gate stack, the low gate voltage is increased to be more effective by causing a negative capacitance phenomenon. The response of the proposed biosensor to four impartial biomolecules with different dielectric constants: protein (k = 8), biotin (k = 2.63), 3-Aminopropyl-triethoxysilane (APTES) (k = 3.57), and streptavidin (k = 0.1) has been investigated. Deoxyribonucleic acid (DNA), a charged biomolecule, is also examined for the dielectric constant of k = 6 concerning both charge (negative and positive) densities. The device is simulated with the commercially available SILVACO ATLASTM TCAD tool. The performance analysis relies on several figures of merit (FOMs) such as DC/RF and sensitivity (including drain current, I ON /I OFF ratio, and subthreshold swing) for both neutral and charged biomolecules. The optimized cavity structure demonstrates a notable sensitivity in drain current (2.7 × 108) and a significant I ON /I OFF sensitivity (1.42 × 1011). One of the main problems with current biosensors is the difficulty and expense of production in the nanoscale realm. © 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.
IoT-Driven Experimental Framework for Advancing Electrical Impedance Tomography
(Institute of Physics, 2024) Ramesh Kumar; Ratneshwar Kumar Ratnesh; Jay Singh; Ashok Kumar; Ramesh Chandra
This research paper focuses on the current emphasis on the latest industrial revolution, particularly the innovative integration of artificial intelligence and the Internet of Things (IoT). The study explores the seamless integration of Electrical Impedance Tomography (EIT) with IoT, presenting a groundbreaking framework where impedance-based sensing plays a vital role in enhancing the dynamic and adaptable qualities of IoT ecosystems. This contribution facilitates intelligent decision-making and real-time monitoring. The research investigates the application of non-invasive Electrical Impedance Tomography for the rapid identification of minor changes in the electrical impedance of the body or a simulated object. Electrodes positioned at the ends of the phantom’s cylinder measure impedance changes through the application of a high-frequency, low-current signal. Image reconstruction employs both forward and inverse solutions, utilizing a triangular finite element method (FEM) mesh to determine conductivity distribution based on recommended phantom models. The integration of IoT enables data capture, enhancing accessibility through remote monitoring. The novel IoT system proves advantageous for various engineering research applications, providing easily monitored parameters in both commercial and clinical contexts. © 2024 The Electrochemical Society (“ECS”). Published on behalf of ECS by IOP Publishing Limited.
Revolutionizing Technology with Spintronics: Devices and Their Transformative Applications
(Elsevier Ltd, 2024) Manoj Kumar Yadav; Ramesh Kumar; Ratneshwar Kumar Ratnesh; Jay Singh; Ramesh Chandra; Abhishek Kumar; Vishal Vishnoi; Gajendra Singh; Ashish Kumar Singh
The scaling of metal oxide semiconductor field effect transistors (MOSFETs) for data storing and logic circuit operation has reached a critical point, beyond which further scaling poses various secondary issues. These problems include short channel effects, hot carrier effects (HCEs), and reliability concerns. However, a promising alternative called spintronics has recently emerged as a highly exciting technology. Spintronics considers both the charge and spin of electrons in device operations and offers superior properties compared to MOSFETs. Researchers have reported numerous spintronics devices that exhibit significant potential in memory and logic circuits when integrated with complementary metal oxide semiconductor (CMOS) technology. These devices not only possess excellent scalability but also consume less power than MOSFETs at the nano-scale level. This article aims to provide a comprehensive review of the current state, future prospects, and challenges associated with spintronics devices. © 2024 Elsevier B.V.
Stability of maize hybrids under drought, rainfed and optimum field conditions revealed through GGE analysis
(Indian Society of Genetics and Plant Breeding, 2023) Ramesh Kumar; Yashmeet Kaur; Abhijit K. Das; Shyam B. Singh; Bhupender Kumar; Manish B. Patel; Jai P. Shahi; Pervez H. Zaidi
Identification of high-yielding and stable cultivars across different environments through multi-location trials are very important in maize breeding. A study was conducted to evaluate 30 maize hybrids in three diverse environments, viz., drought, rainfed and optimal conditions during the years, 2016 and 2017. Environments, genotypes and Genotype × Environment interactions (G × E) were found to be highly significant in both the years. The biplot explained 69.49% of total variation which was partitioned into 53.61 and 15.88% relative to genotype and genotype by environment interaction. Genotype, ZH15449 performed considerably well in 2016 under optimum (113.41 q/ha) and drought (54.19 q/ha) while in 2017, under optimum (82.28 q/ha) and rainfed (65.37 q/ha) conditions. ZH 161285 gave considerable grain yield at all three ecologies (108.70, 74.29, 60.60 q/ha) in year 2016, whereas genotype, ZH 161330 performed well under rainfed (67.76 q/ha) and drought (52.87q/ha) conditions in year 2017. © The Author(s).
Stress-resilient maize for climate-vulnerable ecologies in the Asian tropics
(Southern Cross Publishing, 2020) P.H. Zaidi; Thanh Nguyen; Dang N. Ha; Suriphat Thaitad; Salahuddin Ahmed; Muhammad Arshad; Keshav B. Koirala; Tirtha R. Rijal; Prakash H. Kuchanur; Ayyanagouda M. Patil; Shyam S. Mandal; Ramesh Kumar; S.B. Singh; Bhupender Kumar; J.P. Shahi; M.B. Patel; Murali K. Gumma; Kamal Pandey; Ramesh Chaurasia; Azizul Haque; K. Seetharam; Reshmi R. Das; M.T. Vinayan; Zerka Rashid; S.K. Nair; B.S. Vivek
Most parts of the Asian tropics are hotspots of climate change effects and associated weather variabilities. One of the major challenges with climate change is the uncertainty and inter-annual variability in weather conditions as crops are frequently exposed to different weather extremes within the same season. Therefore, agricultural research must strive to develop new crop varieties with inbuilt resilience towards variable weather conditions rather than merely tolerance to individual stresses in a specific situation and/or at a specific crop stage. C4 crops are known for their wider adaptation to range of climatic conditions. However, recent climatic trends and associated variabilities seem to be challenging the threshold limit of wider adaptability of even C4 crops like maize. In collaboration with national programs and private sector partners in the region, CIMMYT-Asia maize program initiated research for development (R4D) projects largely focusing on saving achievable yields across range of variable environments by incorporating reasonable levels of tolerance/resistance to major abiotic and biotic stresses without compromising on grain yields under optimal growing conditions. By integrating novel breeding tools like - genomics, double haploid (DH) technology, precision phenotyping and reducing genotype x environment interaction effects, a new generation of maize germplasm with multiple stress tolerance that can grow well across variable weather conditions were developed. The new maize germplasm were targeted for stress-prone environments where maize is invariability exposed to a range of sub-optimal growing conditions, such as drought, heat, waterlogging and various virulent diseases. The overarching goal of the stress-resilient maize program has been to achieve yield potential with a downside risk reduction. © 2020 Southern Cross Publishing.
Studies on the arginase, 5′-nucleotidase and lysozyme activity by monocytes from visceral leishmaniasis patients
(2012) Pramod Kumar; Ramesh Kumar; Haushila Pandey; Shyam Sundar; Kalpana Pai
Intracellular pathogenic protozoan infection like visceral leishmaniasis is considered in terms of the overall inflammatory response and the complex cellular interactions leading to formation of the activated macrophage. Analysis of the development of activation is facilitated when operationally defined stage of activation are characterized using a library of objective markers. There is a role of arginase in the immune response supporting its involvement in macrophage effector mechanism in vitro and in vivo. 5′-Nucleotidase a plasma membrane component has been cited as a biochemical correlate of macrophage function in an altered morphological and biochemical state of activation and stimulation. Depression in 5′-nucleotidase activity has been generally referred to as a characteristic marker of activated macrophages. Lysozyme or lysosomal enzymes are released into the endocytic or autophagic vacuole macrophage where they serve the purpose of intracellular digestion of engulfed or segregated materials. In the present study, we have studied levels of arginase and 5′-nucleotidase (marker for macrophage activation) in monocytes of active VL patients and healthy controls. Lysozyme a secretary product of macrophages was also measured in supernatants collected from monocytes of active VL patients and healthy controls. Elevated levels of 5′-nucleotidase were observed in supernatants of monocytes from active VL patients as compared to healthy controls. Low levels of arginase and lysozyme production by monocytes isolated from VL patients were observed as compared to healthy controls. Our studies suggest that low levels of arginase and elevated 5′-nucleotidase activity could be one of the mechanisms in the pathology of VL infection. Low lysozyme activity in patients may account for persistence of Leishmania parasites in VL infections. © 2011 Indian Society for Parasitology.