Publications by authors named "Unnikrishnan V K"

Article Synopsis
  • Oral cancer is prevalent in developing countries like India, largely due to smokeless tobacco use, which contains harmful trace elements.
  • Researchers used laser-induced breakdown spectroscopy (LIBS) to analyze the elemental composition of two types of Paan masala and four packaged tobacco varieties, revealing common elements like calcium, iron, aluminum, nickel, and chromium.
  • The study found that harmful inorganic elements, particularly carcinogenic nickel, are present in both commercially packaged tobacco and Paan masala, highlighting the health risks associated with these products.
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Microplastics are one of the concerning environmental pollutants because of their ubiquity. Their capability to adsorb other environmental pollutants increases the risk even further. Existing identification approaches for microplastic characterization for polymer class and their surface-adsorbed heavy metal detection require the utilization of multiple resources and expertise.

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Background: Plastic Solid Waste (PSW) sorting is a procedure of paramount importance in the mechanical recycling process of plastics waste. The major limitation of the techniques relying on physical properties of plastics is the time taken for analysis and poor accuracy. Spectroscopy has been shown to be a suitable method in plastic sorting due to its atomic and molecular characterization capabilities, and ability to give results in very short time scales.

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Ultratrace elemental detections from a limited volume of samples can offer significant benefits in biomedical fields. However, it can be challenging to concentrate the particles being analyzed in a small area to improve the accuracy of detection. Ring-like deposits on the edges of colloidal droplets are a vexing problem in many applications.

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Infections by multidrug resistant bacteria (MDR) are becoming increasingly difficult to treat and alternative approaches like phage therapy, which is unhindered by drug resistance, are urgently needed to tackle MDR bacterial infections. During phage therapy phage cocktails targeting different receptors are likely to be more effective than monophages. In the present study, phages targeting carbapenem resistant clinical isolate of E.

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Objective: Assess trace elements in betel leaves and slaked lime from different regions of Karnataka, India using Laser Induced Breakdown Spectroscopy (LIBS). Materials and Method: Betel leaves from six different regions of Karnataka were obtained and named (for the purpose of the study) BL1, BL2, BL3, BL4, BL5, and BL6 and they were sun-dried. A single tube of slaked lime was obtained from the local ‘paan’ shop.

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In recent years, the application of lasers for modifying the surface topography of dental biomaterials has received increased attention. This review paper aims to provide an overview of the current status on the utilization of lasers as a potential tool for surface modification of dental biomaterials such as implants, ceramics, and other materials used for restorative purposes. A literature search was done for articles related to the use of lasers for surface modification of dental biomaterials in English language published between October 2000 and March 2023 in Scopus, Pubmed and web of science, and relevant articles were reviewed.

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Herein, the synthesis, characterization, and reduction properties of 2D TiO aerogel powder decorated with BiVO (TiO/BiVO) were investigated for versatile applications. First, 2D TiO was prepared via lyophilization and subsequently modified with BiVO using a wet impregnation method. The morphology, structure, composition, and optical properties were evaluated using transmission electron microscopy (TEM), X-ray diffractometry (XRD), laser-induced breakdown spectroscopy (LIBS), and diffuse reflectance spectroscopy (DRS), respectively.

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The increased use of plastic products and global industrial conditions have contaminated natural resources, especially water, with pollutants such as microplastics and trace elements, including heavy metals. Hence, continuous monitoring of water samples is an urgent requirement. However, the existing microplastic-heavy metal monitoring methodologies require discrete and sophisticated sampling approaches.

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Article Synopsis
  • In today's world, tooth erosion is a common issue, and the study explores effective treatments to prevent demineralization using biomineralization.
  • The research compares the effectiveness of two remineralizing agents—self-assembling peptide P11-4 (SAP P11-4) and calcium silicate plus sodium phosphate (CSSP)—on both intact and demineralized enamel.
  • Results show significant remineralization in demineralized teeth for both agents, but no notable difference in effectiveness between SAP P11-4 and CSSP was found for intact teeth.
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Ever-accumulating amounts of plastic waste raises alarming concern over environmental and public health. A practical solution for addressing this threat is recycling, and the success of an industry-oriented plastic recycling system relies greatly on the accuracy of the waste sorting technique adapted. We propose a multi-modal spectroscopic sensor which combines laser-induced breakdown spectroscopy (LIBS) and Raman spectroscopy in a single optical platform for characterizing plastics based on elemental and molecular information to assist the plastic identification-sorting process in recycling industries.

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There is an urgent need to have reliable technologies to diagnose post-coronavirus disease syndrome (PCS), as the number of people affected by COVID-19 and related complications is increasing worldwide. Considering the amount of risks associated with the two chronic lung diseases, asthma and chronic obstructive pulmonary disease (COPD), there is an immediate requirement for a screening method for PCS, which also produce symptoms similar to these conditions, especially since very often, many COVID-19 cases remain undetected because a good share of such patients is asymptomatic. Breath analysis techniques are getting attention since they are highly non-invasive methods for disease diagnosis, can be implemented easily for point-of-care applications even in primary health care centres.

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Research activities are in full swing globally to translate the use of saliva as a non-invasive and highly potential specimen for clinical diagnostics, particularly for COVID-19 detection. Being comprised of a pool of biomarkers also enriched with ACE-2 receptors, saliva can provide vital information regarding the state of the human body. Advancements in biophotonics tools for saliva investigation may offer promise for developing rapid, highly objective, optical modalities for COVID- 19 detection.

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Human saliva can be treated as a pool of biological markers able to reflect on the state of personal health. Recent years have witnessed an increase in the use of optical devices for the analysis of body fluids. Several groups have carried out studies investigating the potential of saliva as a non-invasive and reliable clinical specimen for use in medical diagnostics.

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Electrons and OH-radicals have been generated by using low-energy laser pulses of 6 ns duration (1064 nm wavelength) to create plasma in a suspension of plasmid DNA (pUC19) in water. Upon thermalization, these particles induce single and double strand breakages in DNA along with possible base oxidation/base degradation. The time-evolution of the ensuing structural modifications has been measured; damage to DNA is seen to occur within 30 s of laser irradiation.

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There are a number of analytical techniques used to study material related problems. Most of them imply experimental determination of parameters and functions by means of which elemental, optical and other properties of materials can be described. Laser Induced Breakdown Spectroscopy (LIBS) and Raman spectroscopy are highly complementary spectroscopic techniques used for lab, in-situ, and remote analyses of materials.

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Low-power laser pulses of 6 ns duration (1064 nm wavelength) have been used to create plasma in an aqueous solution of plasmid DNA (pUC19). Thermal energy electrons and OH radicals in the plasma induce strand breakages in DNA, including double strand breaks and possible base oxidation/base degradation. The time evolution of these modifications shows that it takes barely 30 s for damage to DNA to occur.

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We have developed and standardized a novel hybrid laser-induced breakdown spectroscopy (LIBS)-Raman system using a single pulsed laser and a high-resolution intensified charge coupled device coupled echelle spectrograph. LIBS and Raman spectroscopy are highly complementary techniques which yield elemental and molecular information. Both techniques share an apparently similar instrumental configuration but need entirely different requirements like spectral range covered, resolution, and light-gathering efficiencies.

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Presence of renal-calculi (kidney stones) in human urethra is being increasingly diagnosed over the last decade and is considered as one of the most painful urological disorders. Accurate analysis of such stones plays a vital role in the evaluation of urolithiasis patients and in turn helps the clinicians toward exact etiologies. Two highly complementary laser-based analytical techniques; laser-induced breakdown spectroscopy (LIBS) and micro-Raman spectroscopy have been used to identify the chemical composition of different types of renal-calculi.

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Classification of plastics is of great importance in the recycling industry as the littering of plastic wastes increases day by day as a result of its extensive use. In this paper, we demonstrate the efficacy of a combined laser-induced breakdown spectroscopy (LIBS)-Raman system for the rapid identification and classification of post-consumer plastics. The atomic information and molecular information of polyethylene terephthalate, polyethylene, polypropylene, and polystyrene were studied using plasma emission spectra and scattered signal obtained in the LIBS and Raman technique, respectively.

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Study of copper complex of creatinine and urea is very important in life science and medicine. In this paper, spectroscopic and structural study of a newly synthesized heteroligand complex of copper with creatinine and urea has been discussed. Structural studies have been carried out using DFT calculations and spectroscopic analyses were carried out by FT-IR, Raman, UV-vis absorption and fluorescence techniques.

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An ultra-sensitive hyphenated technique, high-performance liquid chromatography-laser-induced fluorescence detection protein profiling of saliva, is evaluated for early detection and diagnosis of oral premalignancy and malignancy. Calibration sets of protein profiles of unstimulated whole saliva are collected from clinically/pathologically normal, premalignant, and malignant subjects and used as standards. Three parameters-scores of factors, sum of squared residuals, and Mahalanobis distance-derived from principal component analysis of protein profiles of the standard calibration sets, and blind samples are used for "match/no-match" diagnosis of the blind samples.

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The present work deals with the evaluation of a high-performance liquid chromatography laser-induced fluorescence (HPLC-LIF) technique developed in our laboratory for early detection of oral cancer from protein profiles of body fluids. The results show that protein profiles of serum samples from a given class of samples, say, normal, premalignant, or malignant, are statistically very close to each other, while profiles of members of any class are significantly different from other classes. The performance of the technique is evaluated by the use of sensitivity and specificity pairs, receiver operating characteristic (ROC) analysis, and Youden's Index.

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