8 results on '"Khetan J"'
Search Results
2. Link between individual resilience and aggressiveness in dental students and the mediating effect of spirituality: A path analysis.
- Author
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Anjum S, Mishra G, Kankane N, Khetan J, Mahajan N, Patel A, and Chhabra KG
- Abstract
Background: The role of spirituality in people's lives, particularly the lives of health professionals, as well as its impact on mental health issues like anger and aggressiveness and resilience, are particularly significant. Therefore, the purpose of this study was to examine the link between the propensity for violence and personal resilience in dental students by taking into account the function of spirituality as a mediator., Materials and Methods: In this cross-sectional questionnaire survey, 211 volunteer dentistry students participated from a government institute in Jammu and Kashmir, India using a stratified sample procedure. The Spiritual Orientation Scale, Buss and Perry Aggression Questionnaire, and Connor-Davidson Resilience Scale were used to gather the data. SPSS version 20.0 was used for conducting a bivariate analysis to ascertain the directionality connection between the research variables. In addition; structural equation modelling analysis was conducted by Smart PLS., Results: According to the findings, resilience and spirituality have a substantial and positive link (r = 0.468 r = 0.023). Aggressiveness and resilience revealed a statistically significant inverse link (r = 0.325, P = 0.04), but aggression and spirituality had no significant correlation. Spirituality played a substantial mediation influence in the indirect pathway of violence on resilience ( P = 0.001)., Conclusion: According to the study's findings, spirituality can help pupils become more resilient as individuals and can act as a helpful intermediary between aggressiveness and resilience., Competing Interests: There are no conflicts of interest., (Copyright: © 2024 Journal of Education and Health Promotion.)
- Published
- 2024
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3. Analysis of Fn14-NF-κB signaling response dynamics using a mechanistic model.
- Author
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Khetan J and Barua D
- Subjects
- Animals, Cell Nucleus metabolism, Feedback, Physiological, Gene Expression Regulation, Humans, Models, Biological, NF-kappa B metabolism, Signal Transduction, TWEAK Receptor metabolism
- Abstract
Fn14 is a transmembrane receptor protein belonging to the tumor necrosis factor receptor (TNFR) superfamily. Many experimental reports have shown that crosslinking of the receptor by its extracellular ligand TWEAK induces prolonged activation of transcription factor NF-κB. This behavior is distinct from TNF-α receptor, which is a more well-characterized member of the TNFR family. TNF-α receptor, despite sharing many similar molecular interactions with Fn14, only transiently activates NF-κB in response to TNF-α stimulation. Here, we investigate molecular mechanisms that enable Fn14 to display such distinctive behavior. In particular, we focus on two specific features of the Fn14 pathway that potentially give rise to a positive feedback regulation and differentiate it from the TNF-α receptor signaling. By developing a mechanistic model, we analyze how these features may determine the dynamics of an Fn14-NF-κB response. Our analysis reveals that stimulation of Fn14 by TWEAK may generate highly non-linear dynamics, including stable limit cycles and bistable responses. The type of response depends both on the strength and duration of a TWEAK signal. Our predictions and analyses also show that the molecular interactions underlying the positive feedback explain the prolonged activation of NF-κB under certain parameter regimes. In light of the model predictions, we propose possible deregulations of Fn14 leading to its overexpression in solid tumors and tissue injuries., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
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- 2019
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4. Quantitative Analysis of the Correlation between Cell Size and Cellular Uptake of Particles.
- Author
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Khetan J, Shahinuzzaman M, Barua S, and Barua D
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- Cell Line, Tumor, Cytoplasmic Vesicles metabolism, Humans, Nonlinear Dynamics, Cell Size, Endocytosis, Nanoparticles metabolism
- Abstract
The size of a cell is central to many functions, including cellular communication and exchange of materials with the environment. This modeling and experimental study focused on understanding how the size of a cell determines its ability to uptake nanometer-scale extracellular materials from the environment. Several mechanisms in the cell plasma membrane mediate cellular uptake of nutrients, biomolecules, and particles. These mechanisms involve recognition and internalization of the extracellular molecules via endocytic components, such as clathrin-coated pits, vacuoles, and micropinocytic vesicles. Because the demand for an external resource could be different for cells of different sizes, the collective actions of these various endocytic routes should also vary based on the cell size. Here, using a reaction-diffusion model, we analyze single-cell data to interrogate the one/one mapping between the size of the MDA-MB 231 breast cancer cells and their ability to uptake nanoparticles. Our analysis indicates that under both reaction- and diffusion-controlled regimes, cellular uptake follows a linear relationship with the cell radius. Furthermore, this linear dependency is insensitive to particle size variation within 20-200 nm range. This result is counterintuitive because the general perception is that cellular uptake is proportional to the cell volume (mass) or surface area and hence follow a cubic or square relationship with the cell radius. A further analysis using our model reveals a potential mechanism underlying this linear relationship., (Copyright © 2018 Biophysical Society. Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
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5. A spatio-temporal model reveals self-limiting Fc ɛ RI cross-linking by multivalent antigens.
- Author
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Shahinuzzaman M, Khetan J, and Barua D
- Abstract
Aggregation of cell surface receptor proteins by multivalent antigens is an essential early step for immune cell signalling. A number of experimental and modelling studies in the past have investigated multivalent ligand-mediated aggregation of IgE receptors (Fc ɛ RI) in the plasma membrane of mast cells. However, understanding of the mechanisms of Fc ɛ RI aggregation remains incomplete. Experimental reports indicate that Fc ɛ RI forms relatively small and finite-sized clusters when stimulated by a multivalent ligand. By contrast, modelling studies have shown that receptor cross-linking by a trivalent ligand may lead to the formation of large receptor superaggregates that may potentially give rise to hyperactive cellular responses. In this work, we have developed a Brownian dynamics-based spatio-temporal model to analyse Fc ɛ RI aggregation by a trivalent antigen. Unlike the existing models, which implemented non-spatial simulation approaches, our model explicitly accounts for the coarse-grained site-specific features of the multivalent species (molecules and complexes). The model incorporates membrane diffusion, steric collisions and sub-nanometre-scale site-specific interaction of the time-evolving species of arbitrary structures. Using the model, we investigated temporal evolution of the species and their diffusivities. Consistent with a recent experimental report, our model predicted sharp decay in species mobility in the plasma membrane in response receptor cross-linking by a multivalent antigen. We show that, due to such decay in the species mobility, post-stimulation receptor aggregation may become self-limiting. Our analysis reveals a potential regulatory mechanism suppressing hyperactivation of immune cells in response to multivalent antigens., Competing Interests: We declare we have no competing interests.
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- 2018
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6. Determining the effects of PEI adsorption on the permeability of 1,2-dipalmitoylphosphatidylcholine/bis(monoacylglycero)phosphate membranes under osmotic stress.
- Author
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Clark SR, Lee KY, Lee H, Khetan J, Kim HC, Choi YH, Shin K, and Won YY
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- Adsorption, Gene Transfer Techniques, Microscopy, Confocal, Permeability, Scattering, Radiation, 1,2-Dipalmitoylphosphatidylcholine chemistry, Lipid Bilayers, Lysophospholipids chemistry, Monoglycerides chemistry, Osmotic Pressure, Polyethyleneimine chemistry
- Abstract
Polycations are used for a number of biological applications, including antibiotics and gene therapy. One aspect of the use of polycation gene carriers such as polyethylenemine (PEI) in gene therapy that is not well understood is their ability to escape from the vesicles they are internalized in. Here, in an attempt to gain a better understanding of PEI interaction with endosomal lipids under osmotic stress, we performed investigations using monolayers and vesicles derived from a mixture of neutral and negative lipids (1,2-dipalmitoylphosphatidylcholine (DPPC) and bis(monoacylglycero)phosphate (BMP), respectively). X-ray reflectivity (XR) and Langmuir trough measurements confirmed PEI adsorption to the negatively charged membrane. Confocal microscopy imaging indicated that PEI adsorption actually increases the overall integrity of the DPPC/BMP vesicle against osmotic stresses while also causing overall deformation and permeabilization of the lipid membrane, thus leading to leakage of contents from the interior of the vesicle. These confocal microscopy observations were also supported by data gathered by dynamic light scattering (DLS)., Statement of Significance: In recent decades, researchers have investigated polyamine-based gene delivery systems as useful alternatives to viral gene carriers. One step that is crucial to the performance of polyamine gene carriers such as polyethylenemine (PEI) is escape from late endosomal vesicles during intracellular delivery. However, the ability of polyamine/DNA polyplexes to effectively escape from endosomes is a little-understood part of the gene therapy techniques that use these polyplexes. Here, we performed investigations using monolayers and vesicles derived from a mixture of neutral and negative lipids (1,2-dipalmitoylphosphatidylcholine (DPPC) and bis(monoacylglycero)phosphate (BMP), respectively) as model systems for late endosomes in order to examine the interactions of PEI with the DPPC/BMP membranes and study the subsequent effects on the stability and permeability of these membranes., (Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2018
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7. Surface Mechanical and Rheological Behaviors of Biocompatible Poly((D,L-lactic acid-ran-glycolic acid)-block-ethylene glycol) (PLGA-PEG) and Poly((D,L-lactic acid-ran-glycolic acid-ran-ε-caprolactone)-block-ethylene glycol) (PLGACL-PEG) Block Copolymers at the Air-Water Interface.
- Author
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Kim HC, Lee H, Khetan J, and Won YY
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- Biocompatible Materials, Glass chemistry, Hydrophobic and Hydrophilic Interactions, Polylactic Acid-Polyglycolic Acid Copolymer, Rheology, Surface Properties, Air, Caproates chemistry, Ethylene Glycol chemistry, Lactic Acid chemistry, Lactones chemistry, Polyethylene Glycols chemistry, Polyglactin 910 chemistry, Polyglycolic Acid chemistry, Water chemistry
- Abstract
Air-water interfacial monolayers of poly((D,L-lactic acid-ran-glycolic acid)-block-ethylene glycol) (PLGA-PEG) exhibit an exponential increase in surface pressure under high monolayer compression. In order to understand the molecular origin of this behavior, a combined experimental and theoretical investigation (including surface pressure-area isotherm, X-ray reflectivity (XR) and interfacial rheological measurements, and a self-consistent field (SCF) theoretical analysis) was performed on air-water monolayers formed by a PLGA-PEG diblock copolymer and also by a nonglassy analogue of this diblock copolymer, poly((D,L-lactic acid-ran-glycolic acid-ran-caprolactone)-block-ethylene glycol) (PLGACL-PEG). The combined results of this study show that the two mechanisms, i.e., the glass transition of the collapsed PLGA film and the lateral repulsion of the PEG brush chains that occur simultaneously under lateral compression of the monolayer, are both responsible for the observed PLGA-PEG isotherm behavior. Upon cessation of compression, the high surface pressure of the PLGA-PEG monolayer typically relaxes over time with a stretched exponential decay, suggesting that in this diblock copolymer situation, the hydrophobic domain formed by the PLGA blocks undergoes glass transition in the high lateral compression state, analogously to the PLGA homopolymer monolayer. In the high PEG grafting density regime, the contribution of the PEG brush chains to the high monolayer surface pressure is significantly lower than what is predicted by the SCF model because of the many-body attraction among PEG segments (referred to in the literature as the "n-cluster" effects). The end-grafted PEG chains were found to be protein resistant even under the influence of the "n-cluster" effects.
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- 2015
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8. Oral rehabilitation and management of mentally retarded.
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Solanki J, Khetan J, Gupta S, Tomar D, and Singh M
- Abstract
High level of periodontal problems of dental caries are frequently observed in mentally handicapped children. This group of patients presents various problems when they face dental treatments. Identification of such population and providing them affordable oral health care is the new concept. A systematic method for identification and screening of persons with mental retardation has been developed and is being followed. Cost and fear are the most commonly cited barriers to dental care. Physical or mental may lead to deterioration in self-care, and oral care state have a low priority. Risk factors are inter-related and are often barriers to oral health. With advancements in today's world sufficient information and support is available for each and every individual to lead a healthy life which include the access to the oral health care. Factors such as fear, anxiety and dental phobia plays a vital role in acceptance of dental care and also the delaying of dental care. Lack of knowledge of oral and dental disease, awareness or oral need, oral side-effects of medication and organization of dental services are highlighted in the literature. All health personnel should receive training to support the concept of primary oral health care. Training about dealing with such mentally handicapped people should be addressed urgently among the health professionals.
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- 2015
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