Dr. A.K. Tomar
@sajaincollege.ac.in
Assistant Professor, Department of Physics
S.A. Jain (P.G.) College
EDUCATION
Ph.D. in Physics
RESEARCH, TEACHING, or OTHER INTERESTS
Materials Science, Polymers and Plastics, Materials Chemistry, Multidisciplinary
Scopus Publications
Scopus Publications
Abhinav Saini, Vikrant Kumar, Anil Kumar Tomar, Alpana Sharma, and Savita Yadav
Springer Science and Business Media LLC
Kumari Binita Chandra, Vikrant Kumar, Swati Ranjan, Abhinav Saini, Anil Kumar Tomar, Jai Bhagwan Sharma, Sandeep R. Mathur, and Savita Yadav
MDPI AG
The asymptomatic nature, high rate of disease recurrence, and resistance to platinum-based chemotherapy highlight the need to identify and characterize novel target molecules for ovarian cancer. Fibroblast growth factor 8 (FGF8) aids in the development and metastasis of ovarian cancer; however, its definite role is not clear. We employed ELISA and IHC to examine the expression of FGF8 in the saliva and tissue samples of epithelial ovarian cancer (EOC) patients and controls. Furthermore, various cell assays were conducted to determine how FGF8 silencing influences ovarian cancer cell survival, adhesion, migration, and invasion to learn more about the functions of FGF8. In saliva samples, from controls through low-grade to high-grade EOC, a stepped overexpression of FGF8 was observed. Similar expression trends were seen in tissue samples, both at protein and mRNA levels. FGF8 gene silencing in SKOV3 cells adversely affected various cell properties essential for cancer cell survival and metastasis. A substantial reduction was observed in the cell survival, cell adhesion to the extracellular matrix, migration, and adhesion properties of SKOV3 cells, suggesting that FGF8 plays a crucial role in the development of EOC. Conclusively, this study suggests a pro-metastatic function of FGF8 in EOC.
Sarla Naglot, Ayushi Thapliyal, Anil Kumar Tomar, and Savita Yadav
Springer Science and Business Media LLC
Ayushi Thapliyal, Anil Kumar Tomar, Kumari Binita Chandra, Sarla Naglot, Soniya Dhiman, Neeta Singh, Jai Bhagwan Sharma, and Savita Yadav
Springer Science and Business Media LLC
Manoj Kumar Yadav, Ankita Sahu, Anu, Nehaa Kasturria, Anjali Priyadarshini, Archana Gupta, Kanika Gupta, and Anil Kumar Tomar
Springer Nature Singapore
Nirmal Chhikara, Anil Kumar Tomar, Sudip Kumar Datta, and Savita Yadav
Wiley
The cellular and molecular mechanisms of the events that help spermatozoa acquire their fertilizing capability during capacitation and acrosome reaction are not completely understood.
Anil Kumar Tomar and Savita Yadav
Elsevier
Preeti Chhokkar, V. Kumar, Parveen K. Goyal, Shyam Kumar, A.K. Tomar, Anurag Gaur, and Anil Arya
Optical Materials Elsevier BV
Sarla Naglot, Anil Kumar Tomar, Neeta Singh, and Savita Yadav
Elsevier BV
Anil Kumar Tomar, Shailendra Kumar Rajak, Muhammad Aslam MK, Nirmal Chhikara, Sanjay Kumar Ojha, Samiksha Nayak, Shivani Chhillar, Arumugam Kumaresan, and Savita Yadav
Elsevier BV
Preeti Chhokkar, V. Kumar, Parveen K. Goyal, Shyam Kumar, A.K. Tomar, Anurag Gaur, and Anil Arya
Optical Materials Elsevier BV
Abstract The samples of Polyallyl diglycol Carbonate (CR-39) were implanted with 100 keV argon ions at fluences 1 × 1015, 5 × 1015 and 1 × 1016 ions/cm2 to be employed for optical and structural studies. The changes in transmittance, reflectance, optical energy gap and refractive index have been studied through the UV–Vis–NIR spectroscopic technique. The enhancement in reflectivity and a strong reduction in transmittance, particularly in the UV region, are observed after Ar+ implantation in CR-39 samples. The absorbance value remains low ~0.10, 0.15 and 0.20 in the key communication wavelength region i.e. 800–1600 nm for sample implanted at the fluence of 1 × 1015, 5 × 1015, 1 × 1016 Ar+/cm2, respectively. The Optical energy gap (EOPT) is determined to be 0.92 eV for the implanted layer of the sample implanted at the fluence of 1 × 1016 Ar+/cm2, whereas 3.70 eV for the pristine sample. The surface electrical conductivity is increased from ~1.49 × 10−14 S (pristine sample) to ~8.34 × 10−10 S for sample implanted at the fluence of 1 × 1016 Ar+/cm2. The formation of conjugated π-bond (-C C-) structure with Ar+ implantation is confirmed via FTIR and Raman measurements. TGA results are analysed in detail and are found to be in strong agreement with the changes observed in different properties of CR-39 after ion implantation.
Anil Kumar Tomar, Rahul Agarwal, and Bishwajit Kundu
Springer Science and Business Media LLC
Rishi Pal Chahal, Suman Mahendia, A. K. Tomar, and Shyam Kumar
AIP Publishing
A. K. Tomar, Suman Mahendia, Rishipal Chahal, and Shyam Kumar
AIP Publishing
In the present work, Polyaniline doped with Camphor sulfonic acid (CSA) has been synthesized chemically using oxidative polymerization of Aniline taking Ammonium persulfate (APS) as oxidant. The molar ratio of Aniline:CSA:APS was kept as 1:1:1. The conductivity of Polyaniline powder was determined and found to be 4.93 S/cm. The as prepared powder was blended with PMMA at different concentrations using solution casting method taking chloroform as solvent. Their dc conductivity and charge transportation mechanism was analyzed through I-V measurements. A sudden jump of ∼6 orders has been observed in dc conductivity on mixing of 10% by weight of PAni.CSA in PMMA. Furthermore, the charge transportation is also found to be shifting to Poole-Frankel mechanism, which is through Schottky-Richardson mechanism in pure PMMA, on increasing the concentration of PAni.CSA in PMMA.
Rishi Pal Chahal, Suman Mahendia, A. K. Tomar, Anand Malik, Hitender Kumar, and Shyam Kumar
Author(s)
Polymer metal nanocomposites draw attention due to their potential applications in the field of optics. In the present work, PVA/Ag nanocomposites were prepared by in‒situ chemical reduction method and afterward irradiated with gamma rays at various doses. The optical properties of PVA/Ag nanocomposite films before and after gamma irradiation at different doses were investigated. The decline in transmission intensity of PVA/Ag nanocomposite films after gamma irradiation in different wavelength ranges may be utilized to block a particular wavelength/range of wavelengths.Polymer metal nanocomposites draw attention due to their potential applications in the field of optics. In the present work, PVA/Ag nanocomposites were prepared by in‒situ chemical reduction method and afterward irradiated with gamma rays at various doses. The optical properties of PVA/Ag nanocomposite films before and after gamma irradiation at different doses were investigated. The decline in transmission intensity of PVA/Ag nanocomposite films after gamma irradiation in different wavelength ranges may be utilized to block a particular wavelength/range of wavelengths.
A. K. Tomar, Suman Mahendia, Rishipal Chahal, and Shyam Kumar
Author(s)
The blending of polyaniline (PAni) with insulating polymers is an active area of research which has been driven by the possibility to combine the good mechanical properties and processability of the polymer matrix with low electrical resistance. The present paper focuses on the electrical and optical behavior of Poly(methyl methacrylate) (PMMA) blended with different weight percent of PAni loaded with iron (Pani.Fe). We have synthesized PAni.Fe via oxidative chemical polymerization method using Ammonium Persulphate (APS) as oxidant. The conductivity of PAni.Fe powder was found to be 3.53⨯10−2 S/cm. Free standing films of PMMA-PAni.Fe blends were obtained through mixing of different weight % of as prepared PAni.Fe powder with PMMA by solution casting method taking Chloroform as solvent. In order to find the optical characteristics of blended films, these were subjected to UV-Visible-NIR spectroscopy. Conductivity and charge transportation behavior of these blends were analysed through V-I measurements. The optical energy gap of PMMA-PAni.Fe films was found to be reduced to 1.81 eV from 2.72 eV (pure PMMA) and dc conductivity is improved by 6 order in magnitude, with the addition of 10 wt. % of PAni.Fe in PMMA. The charge transportation, which is through Schottky-Richardson conduction mechanism for pure PMMA and its blends with lower concentrations of PAni.Fe also starts shifting towards Poole-Frenkel mechanism as the concentration of PAni.Fe is increased in PMMA-PAni.Fe blends.The blending of polyaniline (PAni) with insulating polymers is an active area of research which has been driven by the possibility to combine the good mechanical properties and processability of the polymer matrix with low electrical resistance. The present paper focuses on the electrical and optical behavior of Poly(methyl methacrylate) (PMMA) blended with different weight percent of PAni loaded with iron (Pani.Fe). We have synthesized PAni.Fe via oxidative chemical polymerization method using Ammonium Persulphate (APS) as oxidant. The conductivity of PAni.Fe powder was found to be 3.53⨯10−2 S/cm. Free standing films of PMMA-PAni.Fe blends were obtained through mixing of different weight % of as prepared PAni.Fe powder with PMMA by solution casting method taking Chloroform as solvent. In order to find the optical characteristics of blended films, these were subjected to UV-Visible-NIR spectroscopy. Conductivity and charge transportation behavior of these blends were analysed through V-I measurements. The...
Vijay Kumar, Wahiduzzaman, Amresh Prakash, Anil Kumar Tomar, Ankit Srivastava, Bishwajit Kundu, Andrew M. Lynn, and Md. Imtaiyaz Hassan
Elsevier BV
Krishna Kant, Anil K. Tomar, Pankaj Sharma, Bishwajit Kundu, Sarman Singh, and Savita Yadav
Bentham Science Publishers Ltd.
Background: A well-known tissue marker of ovarian cancer, Human Epididymis protein 4 (HE4) is the member of whey acidic four-disulfide core proteins family. Purified from human seminal plasma and characterized as a cross-class protease inhibitor, HE4 was proposed to shield spermatozoa against proteolytic factors. However, its exact biological function is unknown. Proteins usually function in conjunction with other proteins in the system and thus, identification and analysis of protein networks become essential to decode protein functions. Objective: This study was performed to explore possible role(s) of HE4 in reproductive physiology via identification of its interactome in human seminal plasma. Methods: HE4 binding proteins were identified through co-immunoprecipitation and MALDITOF/ MS analysis. Also, HE4 was quantified by ELISA in fertile and infertile human seminal plasma samples. Results: Ten HE4 binding proteins were identified, viz. protein phosphatase 1 regulatory subunit 21, protein kinase CLK3, Ankyrin repeat domain-containing protein36A, prostatic acid phosphatase, KIF5C, Spectrin repeat containing, nuclear envelope 1, isoform CRAf, tropomyosin 4, vezatin, utrophin and fibronectin1. This interaction network suggests that HE4 plays multiple roles, specifically in capacitation, sperm motility and maturation. Further, HE4 concentration in human seminal plasma samples was determined by Elisa. Higher HE4 expression in normozoospermia compared to azoospermia and asthenozoospermia affirms its importance in fertilization. Conclusion: Based on identified interactome, it is plausible that HE4 plays a crucial role in fertilization, specifically in sperm maturation, motility and capacitation.
Pankaj Sharma, Anil Kumar Tomar, and Bishwajit Kundu
Elsevier BV
Pankaj Sharma, Anil Kumar Tomar, and Bishwajit Kundu
Elsevier BV
Rahul Agarwal, Jitendra Narayan, Amitava Bhattacharyya, Mayank Saraswat, and Anil Kumar Tomar
Elsevier BV
Vikrant Kumar, Anil Kumar Tomar, Vishal Sahu, Sharmistha Dey, and Savita Yadav
Wiley
An essential protein for bacterial growth, GTPase‐Obg (Obg), is known to play an unknown but crucial role in stress response as its expression increases in Mycobacterium under stress conditions. It is well reported that Obg interacts with anti‐sigma‐F factor Usfx; however, a detailed analysis and structural characterization of their physical interaction remain undone. In view of above‐mentioned points, this study was conceptualized for performing binding analysis and structural characterization of Obg‐Usfx interaction. The binding studies were performed by surface plasmon resonance, while in silico docking analysis was done to identify crucial residues responsible for Obg‐Usfx interaction. Surface plasmon resonance results clearly suggest that N‐terminal and G domains of Obg mainly contribute to Usfx binding. Also, binding constants display strong affinity that was further evident by intermolecular hydrogen bonds and hydrophobic interactions in the predicted complex. Strong interaction between Obg and Usfx supports the view that Obg plays an important role in stress response, essentially required for Mycobacterium survival. As concluded by various studies that Obg is crucial for Mycobacterium survival under stress, this structural information may help us in designing novel and potential inhibitors against resistant Mycobacterium strains.
Vikrant Kumar, Himanshu Narayan Singh, Anil Kumar Tomar, Subrahamanyam Dantham, and Savita Yadav
Informa UK Limited
Searching new targets to counter drug resistance – GTPase-Obg mRNA expression analysis in Mycobacterium under stress and in silico docking with GTPase inhibitors Vikrant Kumar, Himanshu Narayan Singh, Anil Kumar Tomar, Subrahamanyam Dantham and Savita Yadav* Department of Biophysics, All India Institute of Medical Sciences, New Delhi 110029, India; School of Sciences, Noida International University, Gautam Budh Nagar, UP, India; Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, India
Mayank Saraswat, Sakari Joenväärä, Tushar Jain, Anil Kumar Tomar, Ashima Sinha, Sarman Singh, Savita Yadav, and Risto Renkonen
Elsevier BV
Scarcely understood defects lead to asthenozoospermia, which results in poor fertility outcomes. Incomplete knowledge of these defects hinders the development of new therapies and reliance on interventional therapies, such as in vitro fertilization, increases. Sperm cells, being transcriptionally and translationally silent, necessitate the proteomic approach to study the sperm function. We have performed a differential proteomics analysis of human sperm and seminal plasma and identified and quantified 667 proteins in sperm and 429 proteins in seminal plasma data set, which were used for further analysis. Statistical and mathematical analysis combined with pathway analysis and self-organizing maps clustering and correlation was performed on the data set. It was found that sperm proteomic signature combined with statistical analysis as opposed to the seminal plasma proteomic signature can differentiate the normozoospermic versus the asthenozoospermic sperm samples. This is despite the results that some of the seminal plasma proteins have big fold changes among classes but they fall short of statistical significance. S-Plot of the sperm proteomic data set generated some high confidence targets, which might be implicated in sperm motility pathways. These proteins also had the area under the curve value of 0.9 or 1 in ROC curve analysis. Various pathways were either enriched in these proteomic data sets by pathway analysis or they were searched by their constituent proteins. Some of these pathways were axoneme activation and focal adhesion assembly, glycolysis, gluconeogenesis, cellular response to stress and nucleosome assembly among others. The mass spectrometric data is available via ProteomeXchange with identifier PXD004098.
Suman Mahendia, Parveen Kumar Goyal, Anil Kumar Tomar, Rishi Pal Chahal, and Shyam Kumar
Springer Science and Business Media LLC