Displaying publications 1 - 20 of 116 in total

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  1. Fulltext Temperature measurement and optimisation in machining magnesium alloy using RSM and ANOVA
    Viswanathan, R., Ramesh, S., Kamesh Kumar, D., Elango, N.
    Pertanika Journal of Science & Technology, 2017;25(1):255-262.
    MyJurnal
    This paper focuses on examining the ‘cutting zone temperature’ while performing turning operation
    on AZ91Mg alloy using cemented carbide tools. The regression model is developed by using the RSM
    techniques based on experimental results. It is revealed that the cutting speed (v) is the most dominant
    factor affecting cutting zone temperature. The developed models of cutting zone temperature sufficiently
    map within the range of the turning conditions considered. The adequacy and accuracy of the regression
    equation is justified through ANOVA. It is found that the optimal combinations of machining parameters
    minimize the cutting temperature.
  2. Depression and suicidal ideation among adolescents
    Navin Kumar DR
    Med J Malaysia, 2018 12;73(6):443.
    PMID: 30647229
    No abstract provided.
  3. Fulltext Comparative profile of circulating antigenic peptides in CSF, serum & urine from patients with neurocysticercosis diagnosed by immunoblotting
    Sahu PS, Parija S, Kumar D, Jayachandran S, Narayan S
    Parasite Immunol., 2014 Oct;36(10):509-21.
    PMID: 24965663 DOI: 10.1111/pim.12124
    Traditionally serum and/or CSF specimens have been used for detection of either specific antibodies or antigens as a supportive diagnosis of NCC. However, in recent days, much interest has been shown employing noninvasive specimens such as urine. In our study, we identified and compared a profile of circulating antigenic peptides of parasite origin in three different body fluids (CSF, serum and urine) obtained from confirmed NCC cases and control subjects. The circulating antigenic peptides were resolved by SDS-PAGE and subjected to immunoblotting. For confirmation of their origin as parasite somatic or excretory secretory (ES) material, immunoreactivity was tested employing affinity purified polyclonal Taenia solium metacestode anti-somatic or ES antibodies, respectively. Only lower molecular weight antigenic peptides were found circulating in urine in contrast to serum and CSF specimens. Few somatic peptides were identified to be 100% specific for NCC (19·5 kDa in all three specimens; 131, 70 kDa in CSF and serum only; 128 kDa in CSF only). Similarly, the specific ES peptides detected were 32 kDa (in all three specimens), 16·5 kDa (in serum and CSF only), and 15 kDa (urine only). A test format detecting either one or more of these specific peptides would enhance the sensitivity in diagnosis of NCC.
  4. Fulltext Nipah virus infection: current scenario
    Kulkarni DD, Tosh C, Venkatesh G, Senthil Kumar D
    Indian J Virol, 2013 Dec;24(3):398-408.
    PMID: 24426305 DOI: 10.1007/s13337-013-0171-y
    The emergence of Nipah virus (NiV) infection into the pig population and subsequently into the human population is believed to be due to changes in ecological conditions. In Malaysia, A major NiV outbreak occurred in pigs and humans from September 1998 to April 1999 that resulted in infection of 265 and death of 105 persons. About 1.1 million pigs had to be destroyed to control the outbreak. The disease was recorded in the form of a major outbreak in India in 2001 and then a small incidence in 2007, both the outbreaks in West Bengal only in humans without any involvement of pigs. There were series of human Nipah incidences in Bangladesh from 2001 till 2013 almost every year with mortality exceeding 70 %. The disease transmission from pigs acting as an intermediate host during Malaysian and Singapore outbreaks has changed in NIV outbreaks in India and Bangladesh, transmitting the disease directly from bats to human followed by human to human. The drinking of raw date palm sap contaminated with fruit bat urine or saliva containing NiV is the only known cause of outbreak of the disease in Bangladesh outbreaks. The virus is now known to exist in various fruit bats of Pteropus as well as bats of other genera in a wider belt from Asia to Africa.
  5. Fulltext Perioperative very late stent thrombosis treated with thrombosuction
    Sikdar S, Kumar D, Basu S, Mohanty V, Naik J, Banerjee S
    Med J Malaysia, 2012 Feb;67(1):129-30.
    PMID: 22582568
  6. The Significance of Tinospora crispa in Treatment of Diabetes Mellitus
    Thomas A, Rajesh EK, Kumar DS
    Phytother Res, 2016 Mar;30(3):357-66.
    PMID: 26749336 DOI: 10.1002/ptr.5559
    Tinospora crispa is a medicinal plant belonging to the botanical family Menispermiaceae. The plant is widely distributed in Southeast Asia and the northeastern region of India. A related species Tinospora cordifolia is used in Ayurveda for treating a large spectrum of diseases. Traditional healers of Thailand, Malaysia, Guyana, Bangladesh and the southern Indian province of Kerala use this plant in the treatment of diabetes. Many diterpenes, triterpenes, phytosteroids, alkaloids and their glycosides have been isolated from T. crispa. Cell culture and animal studies suggest that the herb stimulates secretion of insulin from β-cells. It also causes dose-dependent and time-dependent enhancement of glucose uptake in muscles. However, in view of the reported hepatotoxicity, this herb may be used with caution. This article reviews the animal studies and human clinical trials carried out using this herb. Areas of future research are also identified.
  7. Fulltext Formulation, characterization, in vitro, in vivo, and histopathological evaluation of transdermal drug delivery containing norfloxacin and Curcuma longa
    Dua K, Chakravarthi S, Kumar D, Sheshala R, Gupta G
    Int J Pharm Investig, 2013 Oct;3(4):183-7.
    PMID: 24350037 DOI: 10.4103/2230-973X.121287
    In an attempt for better treatment of bacterial infections and burn wounds, semisolid formulations containing norfloxacin (NF) and natural wound healing agent Curcuma longa were prepared. The rationale behind employing combination of NF and Curcuma longa is to obtain synergistic wound healing effect. The prepared formulations were compared with silver sulfadiazine cream 1%, USP.
  8. Physiological assessment of in vivo human knee articular cartilage using sodium MR imaging at 1.5 T
    Hani AF, Kumar D, Malik AS, Razak R
    Magn Reson Imaging, 2013 Sep;31(7):1059-67.
    PMID: 23731535 DOI: 10.1016/j.mri.2013.01.007
    Osteoarthritis is a common joint disorder that is most prevalent in the knee joint. Knee osteoarthritis (OA) can be characterized by the gradual loss of articular cartilage (AC). Formation of lesion, fissures and cracks on the cartilage surface has been associated with degenerative AC and can be measured by morphological assessment. In addition, loss of proteoglycan from extracellular matrix of the AC can be measured at early stage of cartilage degradation by physiological assessment. In this case, a biochemical phenomenon of cartilage is used to assess the changes at early degeneration of AC. In this paper, a method to measure local sodium concentration in AC due to proteoglycan has been investigated. A clinical 1.5-T magnetic resonance imaging (MRI) with multinuclear spectroscopic facility is used to acquire sodium images and quantify local sodium content of AC. An optimised 3D gradient-echo sequence with low echo time has been used for MR scan. The estimated sodium concentration in AC region from four different data sets is found to be ~225±19mmol/l, which matches the values that has been reported for the normal AC. This study shows that sodium images acquired at clinical 1.5-T MRI system can generate an adequate quantitative data that enable the estimation of sodium concentration in AC. We conclude that this method is potentially suitable for non-invasive physiological (sodium content) measurement of articular cartilage.
  9. Anti-mycobacterial Constituents from Medicinal Plants; A Review
    Sarkar N, Dey YN, Kumar D, Rajagopal M
    Mini Rev Med Chem, 2021;21(19):3037-3051.
    PMID: 34036911 DOI: 10.2174/1389557521666210525120325
    Effective treatment of tuberculosis has been hampered by the emergence of drug-resistant strains of Mycobacterium therapeutic facilities tuberculosis. With the global resurgence of tuberculosis with the development of multidrug-resistant cases, there is a call for the development of new drugs to combat these diseases. Throughout history, natural products have afforded a rich source of compounds that have found many applications in the fields of medicine, pharmacy and biology, and continued to play a significant role in the drug discovery and development process. This review article depicts the various potential plant extracts as well as plant derived phytoconstituents against the H37rv, the most persistent strains of Mycobacterium tuberculosis and its multidrug strains.
  10. Local gray level S-curve transformation - A generalized contrast enhancement technique for medical images
    Gandhamal A, Talbar S, Gajre S, Hani AF, Kumar D
    Comput Biol Med, 2017 04 01;83:120-133.
    PMID: 28279861 DOI: 10.1016/j.compbiomed.2017.03.001
    Most medical images suffer from inadequate contrast and brightness, which leads to blurred or weak edges (low contrast) between adjacent tissues resulting in poor segmentation and errors in classification of tissues. Thus, contrast enhancement to improve visual information is extremely important in the development of computational approaches for obtaining quantitative measurements from medical images. In this research, a contrast enhancement algorithm that applies gray-level S-curve transformation technique locally in medical images obtained from various modalities is investigated. The S-curve transformation is an extended gray level transformation technique that results into a curve similar to a sigmoid function through a pixel to pixel transformation. This curve essentially increases the difference between minimum and maximum gray values and the image gradient, locally thereby, strengthening edges between adjacent tissues. The performance of the proposed technique is determined by measuring several parameters namely, edge content (improvement in image gradient), enhancement measure (degree of contrast enhancement), absolute mean brightness error (luminance distortion caused by the enhancement), and feature similarity index measure (preservation of the original image features). Based on medical image datasets comprising 1937 images from various modalities such as ultrasound, mammograms, fluorescent images, fundus, X-ray radiographs and MR images, it is found that the local gray-level S-curve transformation outperforms existing techniques in terms of improved contrast and brightness, resulting in clear and strong edges between adjacent tissues. The proposed technique can be used as a preprocessing tool for effective segmentation and classification of tissue structures in medical images.
  11. Fulltext On Comparison of Heat Treated and Non-Heat-Treated LOM Manufactured Sample for Poly(lactic)acid: Mechanical and Morphological View Point
    Singh I, Kumar S, R Koloor SS, Kumar D, Yahya MY, Mago J
    Polymers (Basel), 2022 Nov 24;14(23).
    PMID: 36501501 DOI: 10.3390/polym14235098
    This work reports the comparison of heat-treated and non-heat-treated laminated object-manufactured (LOM) 3D-printed specimens from mechanical and morphological viewpoints. The study suggests that heat treatment of the FDM-printed specimen may have a significant impact on the material characteristics of the polymer. The work has been performed at two stages for the characterization of (a) non-heat-treated samples and (b) heat-treated samples. The results for stage 1 (non-heat-treated samples) suggest that the infill density: 70%, infill pattern: honeycomb, and six number of discs in a single LOM-manufactured sample is the optimized condition with a compression strength of 42.47 MPa. The heat treatment analysis at stage 2 suggests that a high temperature: 65 °C, low time interval: 10 min, works equally well as the low temperature: 55 °C, high time interval: 30 min. The post-heat treatment near Tg (65 °C) for a time interval of 10 min improved the compressive strength by 105.42%.
  12. Fulltext Phytochemistry and pharmacological activity of the genus artemisia
    Bisht D, Kumar D, Kumar D, Dua K, Chellappan DK
    Arch Pharm Res, 2021 May;44(5):439-474.
    PMID: 33893998 DOI: 10.1007/s12272-021-01328-4
    Artemisia and its allied species have been employed for conventional medicine in the Northern temperate regions of North America, Europe, and Asia for the treatments of digestive problems, morning sickness, irregular menstrual cycle, typhoid, epilepsy, renal problems, bronchitis malaria, etc. The multidisciplinary use of artemisia species has various other health benefits that are related to its traditional and modern pharmaceutical perspectives. The main objective of this review is to evaluate the traditional, modern, biological as well as pharmacological use of the essential oil and herbal extracts of Artemisia nilagirica, Artemisia parviflora, and other allied species of Artemisia. It also discusses the botanical circulation and its phytochemical constituents viz disaccharides, polysaccharides, glycosides, saponins, terpenoids, flavonoids, and carotenoids. The plants have different biological importance like antiparasitic, antimalarial, antihyperlipidemic, antiasthmatic, antiepileptic, antitubercular, antihypertensive, antidiabetic, anxiolytic, antiemetic, antidepressant, anticancer, hepatoprotective, gastroprotective, insecticidal, antiviral activities, and also against COVID-19. Toxicological studies showed that the plants at a low dose and short duration are non or low-toxic. In contrast, a high dose at 3 g/kg and for a longer duration can cause toxicity like rapid respiration, neurotoxicity, reproductive toxicity, etc. However, further in-depth studies are needed to determine the medicinal uses, clinical efficacy and safety are crucial next steps.
  13. Marine-derived polysaccharides and their therapeutic potential in wound healing application - A review
    Kumar M, Kumar D, Garg Y, Mahmood S, Chopra S, Bhatia A
    Int J Biol Macromol, 2023 Dec 31;253(Pt 6):127331.
    PMID: 37820901 DOI: 10.1016/j.ijbiomac.2023.127331
    Polysaccharides originating from marine sources have been studied as potential material for use in wound dressings because of their desirable characteristics of biocompatibility, biodegradability, and low toxicity. Marine-derived polysaccharides used as wound dressing, provide several benefits such as promoting wound healing by providing a moist environment that facilitates cell migration and proliferation. They can also act as a barrier against external contaminants and provide a protective layer to prevent further damage to the wound. Research studies have shown that marine-derived polysaccharides can be used to develop different types of wound dressings such as hydrogels, films, and fibres. These dressings can be personalised to meet specific requirements based on the type and severity of the wound. For instance, hydrogels can be used for deep wounds to provide a moist environment, while films can be used for superficial wounds to provide a protective barrier. Additionally, these polysaccharides can be modified to improve their properties, such as enhancing their mechanical strength or increasing their ability to release bioactive molecules that can promote wound healing. Overall, marine-derived polysaccharides show great promise for developing effective and safe wound dressings for various wound types.
  14. Fulltext In Silico Identification of Multi-target Anti-SARS-CoV-2 Peptides from Quinoa Seed Proteins
    Wong FC, Ong JH, Kumar DT, Chai TT
    Int J Pept Res Ther, 2021;27(3):1837-1847.
    PMID: 33867899 DOI: 10.1007/s10989-021-10214-y
    Peptides are promising antagonists against severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). To expedite drug discovery, a computational approach is widely employed for the initial screening of anti-SARS-CoV-2 candidates. This study aimed to investigate the potential of peptides from quinoa seed proteins as multi-target antagonists against SARS-CoV-2 spike glycoprotein receptor-binding domain, main protease, and papain-like protease. Five quinoa proteins were hydrolyzed in silico by papain and subtilisin. Among the 1465 peptides generated, seven could interact stably with the key binding residues and catalytic residues of the viral targets, mainly via hydrogen bonds and hydrophobic interactions. The seven peptides were comparable or superior to previously reported anti-SARS-CoV-2 peptides based on docking scores. Key residues in the seven peptides contributing to binding to viral targets were determined by computational alanine scanning. The seven peptides were predicted in silico to be non-toxic and non-allergenic. The peptides ranged between 546.66 and 3974.87 g/mol in molecular mass, besides exhibiting basic and cationic properties (isoelectric points: 8.26-12.10; net charges: 0.1-4.0). Among the seven peptides, VEDKGMMHQQRMMEKAMNIPRMCGTMQRKCRMS was found to bind the largest number of key residues on the targets. In conclusion, seven putative non-toxic, non-allergenic, multi-target anti-SARS-CoV-2 peptides were identified from quinoa seed proteins. The in vitro and in vivo efficacies of the seven peptides against SARS-CoV-2 deserve attention in future bench-top testing.

    SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10989-021-10214-y.

  15. Quality by Design Perspective for Designing Foam-based Formulation: Current State of Art
    Kumar M, Kumar D, Singh S, Chopra S, Mahmood S, Bhatia A
    Curr Pharm Des, 2024;30(6):410-419.
    PMID: 38747045 DOI: 10.2174/0113816128289965240123074111
    Foam-based delivery systems contain one or more active ingredients and dispersed solid or liquid components that transform into gaseous form when the valve is actuated. Foams are an attractive and effective delivery approach for medical, cosmetic, and pharmaceutical uses. The foams-based delivery systems are gaining attention due to ease of application as they allow direct application onto the affected area of skin without using any applicator or finger, hence increasing the compliance and satisfaction of the patients. In order to develop foam-based delivery systems with desired qualities, it is vital to understand which type of material and process parameters impact the quality features of foams and which methodologies may be utilized to investigate foams. For this purpose, Quality-by-Design (QbD) approach is used. It aids in achieving quality-based development during the development process by employing the QbD concept. The critical material attributes (CMAs) and critical process parameters (CPPs) were discovered through the first risk assessment to ensure the requisite critical quality attributes (CQAs). During the initial risk assessment, the high-risk CQAs were identified, which affect the foam characteristics. In this review, the authors discussed the various CMAs, CPPs, CQAs, and risk factors associated in order to develop an ideal foam-based formulation with desired characteristics.
  16. Microbubbles: Revolutionizing Biomedical Applications with Tailored Therapeutic Precision
    Kumar M, Kumar D, Chopra S, Mahmood S, Bhatia A
    Curr Pharm Des, 2023;29(44):3532-3545.
    PMID: 38151837 DOI: 10.2174/0113816128282478231219044000
    BACKGROUND: Over the past ten years, tremendous progress has been made in microbubble-based research for a variety of biological applications. Microbubbles emerged as a compelling and dynamic tool in modern drug delivery systems. They are employed to deliver drugs or genes to targeted regions of interest, and then ultrasound is used to burst the microbubbles, causing site-specific delivery of the bioactive materials.

    OBJECTIVE: The objective of this article is to review the microbubble compositions and physiochemical characteristics in relation to the development of innovative biomedical applications, with a focus on molecular imaging and targeted drug/gene delivery.

    METHODS: The microbubbles are prepared by using various methods, which include cross-linking polymerization, emulsion solvent evaporation, atomization, and reconstitution. In cross-linking polymerization, a fine foam of the polymer is formed, which serves as a bubble coating agent and colloidal stabilizer, resulting from the vigorous stirring of a polymeric solution. In the case of emulsion solvent evaporation, there are two solutions utilized in the production of microbubbles. In atomization and reconstitution, porous spheres are created by atomising a surfactant solution into a hot gas. They are encapsulated in primary modifier gas. After the addition of the second gas or gas osmotic agent, the package is placed into a vial and sealed after reconstituting with sterile saline solution.

    RESULTS: Microbubble-based drug delivery is an innovative approach in the field of drug delivery that utilizes microbubbles, which are tiny gas-filled bubbles, act as carriers for therapeutic agents. These microbubbles can be loaded with drugs, imaging agents, or genes and then guided to specific target sites.

    CONCLUSION: The potential utility of microbubbles in biomedical applications is continually growing as novel formulations and methods. The versatility of microbubbles allows for customization, tailoring the delivery system to various medical applications, including cancer therapy, cardiovascular treatments, and gene therapy.

  17. Multinuclear MR and multilevel data processing: an insight into morphologic assessment of in vivo knee articular cartilage
    Hani AF, Kumar D, Malik AS, Walter N, Razak R, Kiflie A
    Acad Radiol, 2015 Jan;22(1):93-104.
    PMID: 25481518 DOI: 10.1016/j.acra.2014.08.008
    Quantitative assessment of knee articular cartilage (AC) morphology using magnetic resonance (MR) imaging requires an accurate segmentation and 3D reconstruction. However, automatic AC segmentation and 3D reconstruction from hydrogen-based MR images alone is challenging because of inhomogeneous intensities, shape irregularity, and low contrast existing in the cartilage region. Thus, the objective of this research was to provide an insight into morphologic assessment of AC using multilevel data processing of multinuclear ((23)Na and (1)H) MR knee images.
  18. Fulltext Activity of Plumbago zeylanica Linn. root and Holoptelea integrifolia Roxb. bark pastes in acute and chronic paw inflammation in Wistar rat
    Kumar D, Ganguly K, Hegde HV, Patil PA, Roy S, Kholkute SD
    J Ayurveda Integr Med, 2014 Jan;5(1):33-7.
    PMID: 24812473 DOI: 10.4103/0975-9476.128853
    The pastes prepared from roots of Plumbago zeylanica Linn. and barks of Holoptelea integrifolia Roxb. are widely used by traditional healers for the treatment of arthritis in rural northern Karnataka.
  19. Non-invasive and in vivo assessment of osteoarthritic articular cartilage: a review on MRI investigations
    Hani AF, Kumar D, Malik AS, Ahmad RM, Razak R, Kiflie A
    Rheumatol Int, 2015 Jan;35(1):1-16.
    PMID: 24879325 DOI: 10.1007/s00296-014-3052-9
    Early detection of knee osteoarthritis (OA) is of great interest to orthopaedic surgeons, rheumatologists, radiologists, and researchers because it would allow physicians to provide patients with treatments and advice to slow the onset or progression of the disease. Early detection can be achieved by identifying early changes in selected features of degenerative articular cartilage (AC) using non-invasive imaging modalities. Magnetic resonance imaging (MRI) is becoming the standard for assessment of OA. The aim of this paper was to review the influence of MRI on the selection, detection, and measurement of AC features associated with early OA. Our review of the literature indicates that the changes associated with early OA are in cartilage thickness, cartilage volume, cartilage water content, and proteoglycan content that can be accurately, consistently, and non-invasively measured using MRI. Choosing an MR pulse sequence that provides the capability to assess cartilage physiology and morphology in a single acquisition and advanced multi-nuclei MRI is desirable. The results of the review indicate that using an ultra-high magnetic strength, MR imager does not affect early OA detection. In conclusion, MRI is currently the most suitable modality for early detection of knee OA, and future research should focus on the quantitative evaluation of early OA features using advances in MR hardware, software, and data processing with sophisticated image/pattern recognition techniques.
  20. Age-related rarefaction in retinal vasculature is not linear
    Che Azemin MZ, Ab Hamid F, Aminuddin A, Wang JJ, Kawasaki R, Kumar DK
    Exp Eye Res, 2013 Nov;116:355-358.
    PMID: 24512773 DOI: 10.1016/j.exer.2013.10.010
    The fractal dimension is a global measure of complexity and is useful for quantifying anatomical structures, including the retinal vascular network. A previous study found a linear declining trend with aging on the retinal vascular fractal dimension (DF); however, it was limited to the older population (49 years and older). This study aimed to investigate the possible models of the fractal dimension changes from young to old subjects (10-73 years). A total of 215 right-eye retinal samples, including those of 119 (55%) women and 96 (45%) men, were selected. The retinal vessels were segmented using computer-assisted software, and non-vessel fragments were deleted. The fractal dimension was measured based on the log-log plot of the number of grids versus the size. The retinal vascular DF was analyzed to determine changes with increasing age. Finally, the data were fitted to three polynomial models. All three models are statistically significant (Linear: R2 = 0.1270, 213 d.f., p 
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