Browsing by Author "Kundan Kumar"

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Arsenic remediation through sustainable phytoremediation approaches
(MDPI, 2021) Sudhakar Srivastava; Anurakti Shukla; Vishnu D. Rajput; Kundan Kumar; Tatiana Minkina; Saglara Mandzhieva; Antonina Shmaraeva; Penna Suprasanna
Arsenic contamination of the environment is a serious problem threatening the health of millions of people exposed to arsenic (As) via drinking water and crops grown in contaminated areas. The remediation of As-contaminated soil and water bodies needs to be sustainable, low-cost and feasible to apply in the most affected low-to-middle income countries, like India and Bangladesh. Phytoremediation is an aesthetically appreciable and successful approach that can be used for As decontamination with use of the best approach(es) and the most promising plant(s). However, phytoremediation lacks the required speed and sometimes the stress caused by As could diminish plants’ potential for remediation. To tackle these demerits, we need augment plants’ potential with appropriate technological methods including microbial and nanoparticles applications and genetic modification of plants to alleviate the As stress and enhance As accumulation in phytoremediator plants. The present review discusses the As phytoremediation prospects of soil and water bodies and the usefulness of various plant systems in terms of high biomass, high As accumulation, bioenergy potential, and economic utility. The potential and prospects of assisted phytoremediation approaches are also presented. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Cloning, in silico characterization and expression analysis of TIP subfamily from rice (Oryza sativa L.)
(Elsevier B.V., 2020) Suhas Balasaheb Karle; Kundan Kumar; Sudhakar Srivastava; Penna Suprasanna
Tonoplast Intrinsic Proteins (TIPs) constitute a significant class of the aquaporins. The TIPs control water trade among cytosolic and vacuolar compartments and can also transport glycerol, ammonia, urea, hydrogen peroxide, metals/metalloids, and so forth. Additionally, TIPs are engaged with different abiotic stress responses and developmental processes like leaf expansion, root elongation and seed germination. In this study, ten TIP genes in the rice genome were identified from Oryza sativa ssp indica. Among these, representative groups of TIP genes were cloned and sequenced whilst some TIP sequences showed stop codons in the coding region. The secondary structure analysis represented six conserved transmembrane helices along with the inter-helical regions having conserved motifs. The representative three-dimensional tetrameric design of protein sequence of TIP1;1 displayed key features like NPA motifs, aromatic/arginine (ar/R) selectivity filters, and Froger's residues. The vacuolar localization, transmembrane topological properties, and conserved motif analysis of the cloned genes altogether supported their identity as TIPs. An unrooted phylogenetic tree delineated the relatedness of TIPs from Oryza with different species and bunched them into five clades. The promoter analysis uncovered key regulons associated with administering abiotic stress responses. Gene expression studies showed that TIPs are differentially regulated under salt and drought stress at various time points in shoots and roots of rice. Also, the pattern of expression was found to be significantly variable in five different rice tissues. The heat-map based tissue and stress- specific expression analysis supported the experimental findings. In conclusion, the identification and transcript-level expression studies of TIPs significantly contribute towards the comprehension of their utilitarian significance in the abiotic stress response. © 2020 Elsevier B.V.
Doppler flowmetry and the breast lump
(2001) A.K. Khanna; Niranjan Kumar; Kundan Kumar; Mohan Kumar
Ultrasonic Doppler Flowmetry can detect the abnormal blood flow in the tumor area due to the abnormal vascularisation and it can be detected by Doppler frequency shift and based on it one can identify the nature of lump. The flow pattern in benign tumors is different from that of malignant tumors. We studied 55 patients with breast lumps with the help of VASLAB Ultrasonic Doppler Machine using 8 MHz probe. The recordings were looked for the various parameters as Peak Systolic Frequency, diastolic flow frequency maximum envelop and pulsatility index. All the breast lumps underwent FNAC or excision for confirmation of the disease. Of 55 lumps, 18 had benign lumps while 37 were malignant. Of benign lumps 12 were fibroadenomas, 4 fibrocystic breast diseases and 2 Cystosarcoma phylloides while 37 malignant lumps were 31 infiltrating duct carcinoma, 5 lobular carcinoma and 1 Squamous cell carcinoma. The peak systolic flow was 2429.7±521.6 Hz in malignant lump vs. 1584.6±726.8 Hz in benign lumps (p<0.0001). The minimum diastolic flow was 885.7±862.2 in malignant lump vs. 574.3±314.9 in benign lumps (p<0.0001). DFT (maximum frequency envelop) was 104.07±32.04 in malignant vs. 66.07±28.9 in benign lumps (p<0.0001) while pulsatility index was 0.48±0.12 in malignant while it was 0.48±0.15 in benign (NS). The sensitivity and specificity of Doppler Flowmetry was 84.2% and 72.2% respectively. So with the help of Doppler Ultrasound Flowmetry, one can differentiate in majority of cases the benign lumps from malignant lumps.
EXTRAPERITONEALIZATION FOR SIGMOID VOLVULUS: A REAPPRAISAL
(1995) Ajay K. Khanna; Mahendra K. Misra; Kundan Kumar
A prospective study was carried out in a university hospital to evaluate the results of extraperitonealization of the sigmoid colon in non‐gangrenous signioid volvulus. Eighty‐eight patients with non‐gangrenous sigmoid volvulus were operated upon using the technique of extraperitonealization of the sigmoid colon. There was no recurrence of the volvulus at I to 6 years follow up but 8 patients (9.1%) had constipation and 2 patients (2.2%) had distension of the lower abdomen. Extraperitonealization of the sigmoid colon is a reasonable non‐resection alternative for non‐gangrenous sigmoid volvulus and has minimal morbidity, mortality and no recurrence in our series. Copyright © 1995, Wiley Blackwell. All rights reserved
GC–MS and UHPLC-HRMS based metabolite profiling of Bruguiera gymnorhiza reveals key bioactive compounds
(Elsevier B.V., 2022) Nilesh Lakshman Dahibhate; Padmanabh Dwivedi; Kundan Kumar
This study examines the chemical compositions of most common and widely distributed mangrove species Bruguiera gymnorhiza. Here, the metabolic profiling of B. gymnorhiza leaves via gas chromatography-mass spectrometry and an advanced ultra-high performance liquid chromatography-Q-Exactive Orbitrap high resolution mass spectrometry was performed to screen and identify the bioactive chemical constituents. Total of 75 diverse chemical constituents were identified which belong to various classes, including flavonoids, fatty acids, terpenoids, carboxylic acids, phenolic acids, quinones, and alkaloid. Among these metabolites flavonoids, fatty acids and terpenoids were found to be the major component of B. gymnorhiza. Moreover, the compounds which are key drivers of pharmacological actions of plants such as, gallic acid, hispidulin, rhamnetin, embelin and 5-O-methyl embelin were reported. This study is the first report on the HRMS analysis of chemical constituent of B. gymnorhiza and can be considered as comprehensive map of its biologically important metabolites. © 2022 SAAB
Hydatid cyst of the neck
(BMJ Publishing Group, 1992) Kundan Kumar; Ajay K. Khanna; Mahendra K. Misra
[No abstract available]
Iatrogenic extrahepatic bile duct injury: Prevention is better than repair
(2002) Kundan Kumar; Chitra Gupta; Priya Hazrah; Mallika Tewari; Vinita Srivastava; Vinod K. Dixit; Narendra K. Keswani; Hari S. Shukla
In the 6 year period, between 1994-1999, 40 patients with extrahepatic bile duct injury caused during open cholecystectomy (OC) (35 patients) and laparoscopic cholecystectomy (LC) (5 patients), were referred to one surgical unit from either the University Hospital, Banaras Hindu University (3 patients) or nursing homes (37 patients). These patients were studied with the aim to assess the cause, evaluate the treatment and suggest measures of prevention. Injury to the common bile duct (CBD) was present in 24 patients, common hepatic duct (CHD) in 16 patients and in one patient the accessory cystic duct was injured. In 14 patients the injury was detected during operation. No attempt to repair was made in 4 and an unsuccessful attempt of primary repair was made in 10 patients by the operating surgeon. The skin incision was inadequate, measuring less than 8 cms in 10 patients. Patients presented with bile fistula in 24, obstructive jaundice in 13 patients, peritonitis in 2 and ascites in 1 patient. Further ascites with fistula and obstructive jaundice was present in 3 and 1 patient respectively. Two patients with biliary peritonitis with fistula died and one more patient died after Roux-en-Y choledocho-duodenostomy. In one patient bile fistula closed spontaneously. A variety of bypass procedures were used in the remaining pateints including choledocho-duodenostomy in 6, hepatico-duodenostomy in 3 and Roux-en-Y choledocho-jejunostomy in 20 patients. Six to eighty (median 15) months follow-up has shown stricture formation in one patient who underwent choledocho-duodenostomy and one with repair of CBD on a T-tube. Eight (20%) patients continue to complain of dyspeptic symptoms. In conclusion 1. Extrahepatic bile duct injury occurs in a proportion of patients undergoing cholecystectomy. 2. On detection of the injury during operation the inexperienced surgeon should not make any attempt at primary repair. 3. Roux-en-Y choledocho/hepaticoenteric anastomosis is an adequate method of repair. Further research on the overall prevalence and the causes of iatrogenic injury to the extrahepatic biliary tree is indicated with the participation of all surgeons carrying out the procedure of cholecystectomy.
Insights into the Role of Gasotransmitters Mediating Salt Stress Responses in Plants
(Springer, 2021) Suhas Balasaheb Karle; Akankhya Guru; Padmanabh Dwivedi; Kundan Kumar
Salinity stress is one of the most significant global issues that negatively affect plant growth and development. Modern agricultural practices have expanded the destructive effects of salinity stress, affecting plants through immediate osmotic stress, followed by a slow onset of ionic or hyper-osmotic stress. Plants alteration and resistance to salinity stress involve complex physiological, biochemical, and molecular systems to maintain homeostasis. As of late, the investigation of gaseous molecules in plants has attained much consideration, particularly for abiotic stress. Abiotic stresses generally initiate gasotransmitter (GT) generation in plants. In the interim, these GTs enhance the accumulation and activities of few antioxidant molecules, check the destructiveness of reactive oxygen species (ROS), and improve plant resilience under different stress conditions. The current review presented the role of gaseous molecules in plants under salinity stress, which include nitric oxide (·NO), hydrogen sulfide (H2S), hydrogen gas (H2), carbon monoxide (CO), methane (CH4), and the only gaseous phytohormone ethylene. Further, we highlighted the underlying molecular mechanisms of the gasotransmitter signaling and cross-talks in salinity stress. Also, we presented a general update on the inclusion of GT in salt stress response, including the research gaps and its applications in the advancement of salinity-resistant plants. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.
Overexpression of OsTIP1;2 confers arsenite tolerance in rice and reduces root-to-shoot translocation of arsenic
(Elsevier Masson s.r.l., 2024) Suhas Balasaheb Karle; Yogesh Negi; Sudhakar Srivastava; Penna Suprasanna; Kundan Kumar
Tonoplast Intrinsic Proteins (TIPs) are vital in transporting water and solutes across vacuolar membrane. The role of TIPs in the arsenic stress response is largely undefined. Rice shows sensitivity to the arsenite [As[III]] stress and its accumulation at high concentrations in grains poses severe health hazards. In this study, functional characterization of OsTIP1;2 from Oryza sativa indica cultivar Pusa Basmati-1 (PB-1) was done under the As[III] stress. Overexpression of OsTIP1;2 in PB-1 rice conferred tolerance to As[III] treatment measured in terms of enhanced shoot growth, biomass, and shoot/root ratio of overexpression (OE) lines compared to the wild-type (WT) plants. Moreover, seed priming with the IRW100 yeast cells (deficient in vacuolar membrane As[III] transporter YCF1) expressing OsTIP1;2 further increased As[III] stress tolerance of both WT and OE plants. The dithizone assay showed that WT plants accumulated high arsenic in shoots, while OE lines accumulated more arsenic in roots than shoots thereby limiting the translocation of arsenic to shoot. The activity of enzymatic and non-enzymatic antioxidants also increased in the OE lines on exposure to As[III]. The tissue-specific localization showed OsTIP1;2 promoter activity in root and root hairs, indicating its possible root-specific function. After As[III] treatment in hydroponic medium, the arsenic translocation factor (TF) for WT was around 0.8, while that of OE lines was around 0.2. Moreover, the arsenic content in the grains of OE lines reduced significantly compared to WT plants. © 2024 Elsevier Masson SAS
Performance analysis of dual stator six-phase embedded-pole permanent magnet synchronous motor for electric vehicle application
(John Wiley and Sons Inc, 2023) Raja Ram Kumar; Priyanka Devi; Chandan Chetri; Ankita Kumari; Papu Moni Saikia; Ram Khelawan Saket; Kundan Kumar; Baseem Khan
The motive of this study is to analyse the characteristics of a novel dual-stator embedded-pole six-phase permanent magnet synchronous motor for the application of electric vehicles. A comparative analysis of two separate motor topologies, namely, dual stator embedded-pole six-phase permanent magnet synchronous motor and single stator single rotor surface-mounted permanent magnet synchronous motor, is accomplished to illustrate the performance superiority of the proposed motor. Furthermore, for optimal designing of the proposed motor, a design methodology has also been presented. For the above application, the motor should retain high torque density (HTD) and high reliability. In this regard, a novel H-Shaped flux barrier is introduced in the rotor portion, which fulfils the requirement of HTD. Moreover, the availability of two sets of the stator winding enhances the performance efficiency and ensures the proposed motor's more significant fault-tolerating ability of the motor. For performance evaluation, the Finite Element Method analysis is chosen, as it gives appropriate and precise results. From the above analysis, it is concluded that the HTD and the proposed motor's dynamic performance are better than the above-mentioned conventional motor. © 2022 The Authors. IET Electrical Systems in Transportation published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology.
Plant Metal and Metalloid Transporters
(Springer Nature, 2022) Kundan Kumar; Sudhakar Srivastava
This edited book stands as a one place knowledge hub for plant metal(loid) transporters. The book comprehensively covers holistic aspect of metal(loid) transporters involved in uptake and translocation of essential as well as toxic metal(loid)s. Essential and beneficial metal(loid)s are required in every biological process for normal plant growth and development, however in excess they are toxic. There are toxic metal(loid)s also whose accumulation in plants interferes with normal cellular functioning and hampers growth of plants. Hence, metal(loid) uptake and accumulation in plants is a highly regulated phenomenon involving the role of several transporters, enzymes, metabolites, transcription factors and post translational modifications. The book contains chapters from the experts and the contents of the book are presented in simple language and represented through beautiful and scientifically informative figures and tables. This book is of interest to teachers, researchers, doctoral and graduate students working in the area of plant physiology, environmental biotechnology, plant biotechnology metal(loid) stress, phytoremediation and crop biofortification. © The Editor(s)(if applicable) and The Author(s),under exclusive license to Springer Nature Singapore Pte Ltd. 2022.
Preface
(Springer Nature, 2022) Kundan Kumar; Sudhakar Srivastava
[No abstract available]
Residual breast tissue in the skin flaps after Patey mastectomy
(2004) Mallika Tewari; Kundan Kumar; Mohan Kumar; H.S. Shukla
Background & objectives: Patey mastectomy implies complete removal of breast tissue. Likely area where residual breast tissue may be left is under the skin flaps. There is no study examining left over breast tissue under the Patey mastectomy skin flap. The present study was undertaken to study the presence of residual breast tissue in skin flaps after Patey mastectomy in patients with breast cancer. Methods: In 37 patients of breast cancer undergoing Patey mastectomy, biopsy from under the skin flap at central point of 4 quadrants (upper outer, upper inner, lower inner and lower outer), 3 cm from cut margin of skin was taken to examine for residual breast tissue. Results: In 8 of 37 (21.6%) cases residual breast tissue and in 3 of these (37.5%) tumour tissue was found under the skin flap. Interpretation & conclusion: Overall in 21.6 per cent biopsies from under the skin flap revealed information of probable therapeutic importance. This information may in future serve as an additional prognostic factor to consider irradiation to reduce the incidence of local recurrence in flap positive patients.
Rice Cultivation Under Abiotic Stress
(Elsevier, 2025) S. Srivastava; Kundan Kumar; Om Parkash Dhankher
Rice Cultivation under Abiotic Stresses: Challenges and Opportunities provides a unique look at three key factors in optimized rice yield -cultivation practices, understanding abiotic stress response, and mitigation strategies -enabling the reader to better understand the cause, effect, and means of protecting rice crop yield. It is a uniquely comprehensive resource for advancing the sustainable and optimal production of rice that will be a valuable resource for researchers and advanced students in Agriculture, Agronomy, Botany, Plant Physiology, and Environmental Science. Rice is the primary source of energy for over half of the world’s people. It can play a vital role against mal and under nutrition, but as climate and other abiotic challenges continue to impact yield, steps need to be taken to ensure production. © 2025 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Simplified Sutured Sacral Rectopexy for Complete Rectal Prolapse in Adults
(1996) Ajay K. Khanna; Mahendra K. Misra; Kundan Kumar
Objective: To assess the results of simplified sutured sacral rectopexy for complete rectal prolapse. Design: Prospective study. Setting: University hospital, India. Subject: 65 patients with complete rectal prolapse treated by modified sutured sacral rectopexy. Main outcome measures: Morbidity, mortality and recurrence. Results: During a follow-up of 2-10 years (mean 5.4 years) none of the patients developed a recurrence of complete prolapse of the rectum but 3(5%) developed mucosal prolapse. The incontinence improved in 12 of 16 patients (75%) and constipation improved in 5 of 6 (83.3%). Conclusion: We conclude that the simplified sutured sacral rectopexy is a simple operation for treating complete rectal prolapse in adults, and gives good results.