Browsing by Author "Pawan Kumar Dubey"

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Analyzing gene expression through real time PCR while neo-tissue regeneration using developed tissue constructs
(Bentham Science Publishers, 2020) Divakar Singh; Tarun Minocha; Satyavrat Tripathi; Rupika Sinha; Shubhankar Anand; Hareram Birla; Vivek Kumar Pandey; Arun Rawat; Smita Gupta; Sanjeev Kumar Yadav; Pawan Kumar Dubey; Pradeep Srivastava
Real-time PCR offers a wide area of application to analyze the role of gene activity in various biological aspects at the molecular level with higher specificity, sensitivity and the potential to troubleshoot with post-PCR processing and difficulties. With the recent advancement in the development of functional tissue graft for the regeneration of damaged/diseased tissue, it is effective to analyze the cell behaviour and differentiation over tissue construct toward specific lineage through analyzing the expression of an array of specific genes. With the ability to collect data in the exponential phase, the application of Real-Time PCR has been expanded into various fields such as tissue engineering ranging from absolute quantification of gene expression to determine neo-tissue regeneration and its maturation. In addition to its usage as a research tool, numerous advancements in molecular diagnostics have been achieved, including microbial quantification, determination of gene dose and cancer research. Also, in order to consistently quantify mRNA levels, Northern blotting and in situ hybridization (ISH) methods are less preferred due to low sensitivity, poor precision in detecting gene expression at a low level. An amplification step is thus frequently required to quantify mRNA amounts from engineered tissues of limited size. When analyzing tissue-engineered constructs or studying biomaterials-cells interactions, it is pertinent to quantify the performance of such constructs in terms of extracellular matrix formation while in vitro and in vivo examination, provide clues regarding the performance of various tissue constructs at the molecular level. In this chapter, our focus is on Basics of qPCR, an overview of technical aspects of Real-time PCR; recent Protocol used in the lab, primer designing, detection methods and troubleshooting of the experimental problems. © 2020, Bentham eBooks imprint. All rights reserved.
Aromatic Plants, Essential oils, Carminatives, Tea Plants and Expectorant Herbs for the Management of COVID-19
(Bentham Science Publishers, 2023) Sonal Upadhyay; Ravi Bhushan; Pawan Kumar Dubey; Bashir A. Sheikh; Mithun Rudrapal; James H. Zothantluanga
SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2) leads to coronavirus disorder (COVID-19). It was detected in Wuhan City, China, in December 2019 and extended to different provinces in China. The drug discovery strategy that holds the thrust of the COVID-19 pandemic is the existing trial of broad-spectrum antiviral drugs. However, molecular docking combined with chemical synthesis assists in discovering various synthetic agents, above one-third of FDA (Food and Drug Administration)- are naturally occurring products as approved drugs. Natural derivative products from different sources of fungus, plant and marine have been abundant in nutrition/phytochemicals to prevent various disease discoveries for many diseases’ prevention. There are scarcely any country that is left intact by the coronavirus outbreak. Only the considerable well-known health threat still now requires it to be managed as early as possible. To date, there is no development of drugs or vaccines that have been proven clinically against COVID-19. Various secondary phytoconstituents with antiviral activities have been extracted from medicinal herbs. Different research works have been demonstrated all over the globe to find antiviral medication effectiveness against SARS-CoV-2 in COVID-19 pandemic. The best preventive measures against COVID-19 infections would be searching for the molecules responsible for modifying or disturbing any pathways related to the virus replication cycle. Natural compounds are capable of altering or inhibiting the configuration of the structural protein of (spike glycoprotein), non-structural proteins (3-chymotrypsin-like protease, papain-like protease, helicase, and RdRP) and accessory proteins encoded by the SARS-CoV-2 genome that are required to be investigated.Hence, various natural products and herbal extracts may prove as potent therapeutics in treating the symptoms related to SARS-CoV-2 infection. In this context, we will present some traditional plants/herbs that are found effective against viral activities and reduce the contamination risk by Coronavirus and cure some symptoms of COVID-19, mainly respiratory problems. © 2023, Bentham Science Publishers.
Association of intronic variants (Apal and Bsml) of vitamin D receptor gene with uterine leiomyoma among North Indian women
(Elsevier B.V., 2025) Sonal Tiwari; Rakesh Kumar Gupta; Sakshi Agarwal; Amita Diwakar; Arun K. Bind; Pawan Kumar Dubey
Background: Understanding the genetic factors involved in the Uterine Leiomyoma (UL) development is crucial for exploring the complexities of UL disorders. This study aimed to examine genetic association between UL incidence and intronic polymorphisms of vitamin D receptor gene in north Indian population. Methodology: Total 200 subjects (100 healthy women and 100 with uterine leiomyomas) of age- and gender-matched control subjects, were genotyped for BsmI (rs1544410) and ApaI (rs7975232) polymorphisms in the VDR gene using TETRA ARMS PCR, followed by Sanger sequencing validation. Levels of VDR mRNA and vitamin D were also assessed through quantitative real-time PCR and ELISA respectively. The association of these variants with leiomyomas was analyzed, along with clinico-pathological (obesity) association. Results: ApaI revealed a significant association with UL, especially for the TG genotype (OR = 2.38; 95 % CI, 1.26–––4.51; p = 0.003). In a similar manner, ApaI is associated with an increased risk for UL with all three genetic models. Comparing VDR ApaI polymorphism between obese and non-obese patients revealed that AC genotype was significantly (OR = 3.71; 95 % CI, 1.53––9.11; p = 0.002) associated with a reduced risk of UL in non-obese patients. The expression of VDR mRNA was two times lower in patients with UL (p < 0.001), along with decreased serum vitamin D levels (p < 0.001). A significant association was also observed between VDR ApaI variant with reduced mRNA expression, vitamin D level and obesity. However, no associations were observed among Bsm1 VDR genotypes and ULs. Conclusion: This study found significant association between the VDR intronic ApaI polymorphism (rs7975232) and the incidence of UL. This VDR variant showed significant association with reduced VDR mRNA expression and serum vitamin D levels in UL patients. However, no significant association was observed between BsmI VDR polymorphism (rs1544410) and UL in North Indian women. © 2025 Elsevier B.V.
Clean and Efficient Synthesis of Graphene Nanosheets and Rectangular Aligned-Carbon Nanotubes Bundles Using Green Botanical Hydrocarbon Precursor: Sesame Oil
(American Scientific Publishers, 2014) Rajesh Kumar; Rajesh Kumar Singh; Pradip Kumar; Pawan Kumar Dubey; R.S. Tiwari; O.N. Srivastava
A facile and rapid approach was used for the clean and efficient synthesis of graphene nanosheets (GNSs) and rectangular aligned carbon nanotubes (RA-CNTs) bundles. These structures were formed at different hot zones of the furnace. The sesame oil, a green natural precursor is used first time as a hydrocarbon precursor for the synthesis of GNSs and well packed RA-CNTs bundles. GNSs and RA-CNTs bundles were synthesized by spray pyrolysis of sesame oil with ferrocene as a catalyst, inside silica tube at 800 °C. This new precursor is appropriate for the synthesis of high quality and clean GNSs and RA-CNTs bundles. GNSs show the formation of few layers graphene which contains 6-8 graphene layers. FTIR spectra confirm that there is no more functional group attached on the surface of as synthesized materials. Growth of these nanostructures strongly depends on the temperature inside the tube. Raman studies show intense 2D peak as compared to G peak, signifying presence of GNSs. The investigations reveal that these novel carbon nanostructures synthesized by sesame oil are clean from carbonaceous impurities. © 2014 by American Scientific Publishers.
Freestanding 3D Graphene-Nickel Encapsulated Nitrogen-Rich Aligned Bamboo Like Carbon Nanotubes for High-Performance Supercapacitors with Robust Cycle Stability
(Wiley-VCH Verlag, 2015) Rajesh Kumar; Rajesh Kumar Singh; Pawan Kumar Dubey; Dinesh Pratap Singh; Ram Manohar Yadav; Radhey Shyam Tiwari
3D hierarchical structures are reported based on graphene-nickel encapsulated nitrogen-rich aligned bamboo like carbon nanotubes, which show not only high-performance supercapacitance behavior but also a great robust cyclic stability. A facile synthesis route is developed of 2D nickel oxide decorated functionalized graphene nanosheets (2D-NiO-f:GNSs) hybrids and 3D nitrogen doped bamboo-shaped carbon nanotubes (NCNTs) vertically standing on the functionalized graphene nanosheets (3D-NCNT@f:GNSs) by using a thermal decomposition method. The chemical reduction and morphology-dependent electrochemical response are investigated. The enhanced specific capacitance of 3D-NCNT@f:GNSs as compared to that of 2D-NiO-f:GNSs suggests the synergistic effects and indicates the importance of energy storage and superior long-term cycling performance that are achieved. This 3D-NCNT@f:GNSs hybrid shows a remarkable cycling stability with a maximum power density of 12.32 kW kg-1 and maximum energy density of 109.13 Wh kg-1 due to the good connection of NCNT and f:GNSs. This unique 3D nano network architecture enables the availability of large surface areas of NCNT, thus endowing the nanohybrids with high specific capacitance and excellent reusability. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Genetic association of vitamin D receptor polymorphisms (ApaI, BsmI, and FokI) with gestational diabetes mellitus in North Indian women: a case–control study
(BioMed Central Ltd, 2025) Rakesh Kumar Gupta; Sonal Tiwari; Sakshi Agarwal; Amita Diwakar; Pawan Kumar Dubey
Background: Gestational diabetes mellitus (GDM) affects nearly 14% of pregnancies and imposes an increased risk of adverse outcomes for both pregnant women and their developing babies. This study examined the genetic association of vitamin D receptor (VDR) variants (ApaI, BsmI, and FokI) with GDM in the North Indian population. Methods: Tetra-ARMS PCR was used for genotyping of VDR variants followed by Sanger sequencing validation. The genotypes of VDR variants, Odds ratio (OR) and confidence interval (CI) were further analyzed in GDM and determined by different genetic models. Results: The C allele of ApaI (rs7975232) genotype significantly associated with increased risk of GDM compared to the TT genotype carrying pregnant women. The A allele of BsmI, and A allele of FokI genotypes was found as a risk factor for GDM. Sanger sequencing confirmed the changes in ApaI (T/C), BsmI (A/G), and FokI (A/G) gene sequence which linked to GDM. The circulatory vitamin D3 levels were significantly lower in GDM patients whereas, homozygous genotypes of ApaΙ (CC, P < 0.0884), BsmI (GG, P < 0.8192) and FokI (GG, P < 0.0303) was associated with vitamin D deficiency. On other hand, mother age, blood glucose and glycated haemoglobin (HbA1c) were significantly higher in the GDM group vs. the control group. Conclusion: VDR ApaI (rs7975232) and FokI (rs2228570) polymorphisms, HbA1c level, and vitamin D are associated with the risk of GDM in the north Indian population. Considering the impact of vitamin D3 level, it is suggested that pregnant Indian women must consider vitamin D supplementation during pregnancy. © The Author(s) 2025.
Highly zone-dependent synthesis of different carbon nanostructures using plasma-enhanced arc discharge technique
(Kluwer Academic Publishers, 2015) Rajesh Kumar; Rajesh Kumar Singh; Pawan Kumar Dubey; Ram Manohar Yadav; Dinesh Pratap Singh; R.S. Tiwari; O.N. Srivastava
Three kinds of carbon nanostructures, i.e., graphene nanoflakes (GNFs), multi walled carbon nanotubes (MWCNTs), and spherical carbon nanoparticles (SCNPs) were comparatively investigated in one run experiment. These carbon nanostructures are located at specific location inside the direct current plasma-assisted arc discharge chamber. These carbon nanomaterials have been successfully synthesized using graphite as arcing electrodes at 400 torr in helium (He) atmosphere. The SCNPs were found in the deposits formed on the cathode holder, in which highly curled graphitic structure are found in majority. The diameter varies from 20 to 60 nm and it also appears that these particles are self-assembled to each other. The MWCNTs with the diameter of 10–30 nm were obtained which were present inside the swelling portion of cathode deposited. These MWCNTs have 14–18 graphitic layers with 3.59 Å interlayer spacing. The GNFs have average lateral sizes of 1–5 μm and few of them are stacked layers and shows crumpled like structure. The GNFs are more stable at low temperature (low mass loss) but SCNPs have low mass loss at high temperature. © 2015, Springer Science+Business Media Dordrecht.
Hydrothermal synthesis of a uniformly dispersed hybrid graphene-TiO2 nanostructure for optical and enhanced electrochemical applications
(Royal Society of Chemistry, 2015) Rajesh Kumar; Rajesh Kumar Singh; Pawan Kumar Dubey; Dinesh Pratap Singh; Ram Manohar Yadav; Radhey Shyam Tiwari
Highly dispersed TiO2 nanoparticles on graphene nanosheets were achieved by hydrothermal treatment of graphene nanosheets obtained by modified Hummer's method followed by thermal exfoliation. The hybrid graphene TiO2 nanostructure composite (H-GTN) showed enhanced optical and electrochemical properties for future application as a supercapacitor. The structural, optical and electrochemical properties of the composite are systematically investigated. The as-prepared H-GTN showed a quenching phenomenon of its photoluminescence properties, which was attributed to the specific properties of graphene. Remarkably, the CV test obtained for H-GTN showed a very high specific capacitance value up to 530 F g-1 at a scan rate of 3 mV s-1, and nearly stable capacitance of 400 F g-1 above 20 mV s-1. The cyclic stability test shows stable behavior after some initial cycles and the stability was then retained without obvious aging or performance degradation, showing long cyclic stability. This is attributed to the excellent electrochemical performance of the H-GTN electrode material for practical application in energy storage devices. © The Royal Society of Chemistry 2015.
Integration of transcriptomics and metabolomics data revealed role of insulin resistant SNW1 gene in the pathophysiology of gestational diabetes
(Nature Research, 2025) Ravi Bhushan; Rimjhim Trivedi; Ritu Raj; Anjali Rani; Sangeeta Rai; Anima Tripathi; Shiv Govind Rawat; Ajay Kumar; Dinesh Kumar; Pawan Kumar Dubey
Gestational Diabetes Mellitus (GDM) is an emerging maternal health problem with increasing incidences. The lack of complete understanding of its pathophysiological mechanisms and novel regulatory biomarkers makes early diagnosis difficult. High-throughput RNA sequencing and computational bioinformatics analyses were conducted to identify novel hub genes, and their regulatory mechanisms were validated through qRT-PCR, western blot, and siRNA-mediated knockdown studies. Intermediate metabolites and circulatory levels of amino acids in the serum of GDM patients and healthy controls were measured. Transcriptomic studies identified SNW1 as the most sensitive and specific biomarker, significantly up-regulated in GDM (fold change = 1.09; p < 0.001). Metabolomic studies indicated significantly elevated gluconeogenesis in GDM, evidenced by decreased levels of alanine and increased levels of pyruvate and glucose compared to controls. siRNA-mediated knockdown of SNW1 in PANC1 cells resulted in significant down-regulation of alanine aminotransferase (ALT/GPT) and insulin receptor substrate (IRS1), while glucose transporters (GLUT2/GLUT4) and insulin (INS) were significantly up-regulated at both mRNA and protein levels. This study identified SNW1 as a novel insulin-resistant gene that induces hyperglycemia by elevating gluconeogenesis and decreasing glucose uptake. SNW1 may be considered a potential therapeutic target with clinical utility for the management of GDM. © The Author(s) 2025.
Phyto-Fingerprinting of Putranjiva roxburghii Wall. Leaf Extract and its In Vitro Anti-Inflammatory Activity
(Springer, 2025) Jayhind Kumar Chauhan; Pradeep Vijay Dinesh Kumar; Pawan Kumar Dubey; Anima Tripathi
Putranjiva roxburghii is an important medicinal plant utilized for remedy of female reproductive ailments. Its seed extract is being used as a uterine health booster due to the presence of several pharmaceutically important phytochemicals. However, the presence of phytochemicals in its leaf is still unexplored. The present study was designed to explore phytochemical finger printing and assessment of anti-oxidant and anti-inflammatory activities of hydroalcoholic leaf extract of P. roxburghii (HALEPR). The qualitative, quantitative phytochemical of flavonoid, phenol and HRA-MS analysis of HALEPR carried out along with antioxidant and in vitro membrane stabilization and protein denaturation assay of anti-inflammatory activity were have been analyzed. Results of qualitative phytochemical screening of HALEPR denotes the existence of phenol, flavonoids, alkaloids, coumarins, steroids, saponins, tannins, anthroquinone and carbohydrates. The quantitative phytochemical of flavonoid and phenol was done which revealed the presents of total phenol and flavonoid. High resolution accurate-mass spectrometry (HRA-MS) study was also done for the identification of bioactive compounds from the HALEPR, which showed the presence of various phytochemicals such as luteolin 3′- (3″-acetylglucuronide), luteolin 4′-methyl ether 7-glucoside, quercetin-3β-D-glucoside, 8-hydroxyluteolin 4′-methyl ether 8-glucuronide, quercetin 3-xylosyl- (1- > 2) -rha mnosyl- (1- > 6) –glucoside, quercetin-3β-D-glucoside, myricetin 3- (3-6-diacetylglucosyl) - (1- > 4) - (2″,3″-diacetylrhamnoside), apigetrin, isorhamnetin, catechin 7,3′-Di-O-β-D glucopyranoside, luteolin 7-methylglucuronide, apigenin-8-C-α -l-arabinopyranoside, naringenin 7- O-β-D-glucoside 6″-acetate,ohobanin, shogaol, ginkgetin and amoritin. The HELPER is shown to have the presence of anti-oxidant and anti-inflammatory activities as demonstrated by DPPH (1, 1-diphenyl,2-picrylhydrazyl) and membrane lysis assays. Our findings reveal the presence of phytochemicals in HALEPR that have significant antioxidant and anti-inflammatory activity. The bioactivities were identified using chemical characterization like HRA/MS and biological assessments like anti-inflammatory and antioxidant assays. Future research may focus on isolating specific molecules, conducting in vivo tests, and creating HALEPR-based formulations for clinical application as anti-inflammatory drugs. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.
Pink Fluorescent Carbon Dots Derived from the Phytomedicine for Breast Cancer Cell Imaging
(Wiley-Blackwell, 2020) Gaurav Gopal Naik; Md Bayazeed Alam; Vivek Pandey; Pawan Kumar Dubey; Avanish S. Parmar; Alakh N. Sahu
Phytomedicines have been beneficial to humankind for the treatment of implacable ailments from time immemorial. In this report, we have synthesized a carbon dots as a photomedicine from traditional phytomedicine Andrographis paniculata which is widely spread across Southern and Southeastern Asia. Interestingly, these carbon dots exhibited unique pink fluorescence that is perceptibly distinctive from the previous reports. The inherent properties of carbon dots were characterised using Transmission Electron Microscopy, Fluorescence spectroscopy, Absorption spectroscopy, Fourier transform infrared spectroscopy, Selected area diffraction, X-Ray Diffraction, and Energy Dispersive X-ray Spectroscopy. Furthermore, thermal stability of carbon dots was determined using Thermo gravimetric analysis. The carbon dots are fabricated to possess breast cancer cell bioimaging applications apart from anti-bacterial activities against clinically isolated strains of gram-positive and gram-negative bacteria and free radicals sensing and scavenging attributes. These findings establish carbon dots as a potential photomedicine with wide healthcare applications. © 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Pressure-dependent synthesis of high-quality few-layer graphene by plasma-enhanced arc discharge and their thermal stability
(Kluwer Academic Publishers, 2013) Rajesh Kumar; Rajesh Kumar Singh; Pawan Kumar Dubey; Pradip Kumar; Radhey Shyam Tiwari; Il-Kwon Oh
In this article, a simple and cost-effective method to produce high-quality few-layer graphene (FLG) sheets (∼4 layers) have been achieved by the direct current arc discharge under argon atmosphere, using pure graphite rods as the electrodes. Ar was used as a buffer gas with pure graphite rods as anode and cathode electrodes. We explored the suitable conditions for producing FLG by changing the Ar gas pressure inside the arcing chamber. This method has several advantages over the previous methods to produce graphene for research applications. No toxic and hazardous intercalant was used for producing FLG in this process. The optimum Ar pressure was 500 Torr, for producing minimum number of FLG and this also shows the good thermal stability. The FLG product so obtained has been characterized by X-ray diffraction, scanning and electron microscopy, Raman and Fourier transform infrared spectroscopy. Thermal stabilities of FLG were determined by thermal gravimetric analysis. © 2013 Springer Science+Business Media.
Prevalence of disability in Uttar Pradesh: A district-wise study
(Indian Journal of Public Health Research and Development, 2019) Ravi Prakash Jha; Krittika Bhattacharyya; Durgesh Shukla; Nisha Tiwari; Pawan Kumar Dubey
Information on disability is essential for the government to formulate policies, allocate adequate resources and implement appropriate programmes. The objective of this study was to measure the prevalence of disability and the estimation of distribution of disabilities by gender, advancing age, districts, geographical regions,work and marital status in the Uttar Pradesh. Method: We analyzed the 2011 Census data of Uttar Pradesh. Age-adjusted disability rates and disability rates per 100 000 population were calculated. Results: There were 4157514 individuals with disability in Uttar Pradesh in 2011 accounting for a disability rate of 2081 per 100 000 populations. The disability in hearing, seeing, and movement was most predominant with rates of 514, 382 and 339 per 100 000 respectively of the 71 districts, age-standardized disability rates in 20 districts were above the state average of 2081 per 100 000 population. In all kinds of disability there was mostly male predominance in both rural and urban areas across all agecategories. Conclusion: About 2 in every 100 person in Uttar Pradesh (2080 per 100 000 persons) is either physically or mentally disabled. Disability rates reflect the overall health status of the population. Identification of the underlying causes and employing effective and focused preventive strategies will help to reduce the burden of disability and maximize the quality of life in Uttar Pradesh. © 2019, Indian Journal of Public Health Research and Development. All rights reserved.
Re-Investigation of Entrance Channel Effects in Heavy-Ion Fusion-Fission Dynamics
(Pleiades Publishing, 2025) Pawan Kumar Dubey; Ajay Vinod Kumar
Abstract: The experimental calculation of pre-scission neutron multiplicity is a highly valuable method for determining the fission timescale. In this study, we have determined the fission time for three consecutive shell-closure compound nuclei, namely 212Rn, 213Fr, and 214Ra (with a neutron number of 126) forming via different entrance channel, as well as three consecutive non shell-closure compound nuclei, namely 214Rn, 215Fr, and 216Ra (with a neutron number of 128). To accomplish this, we have utilized the statistical model code JOANNE2 and incorporated available experimental data from EXFOR. Our observation shows that non-shell closure compound nuclei exhibit more dissipation compared to shell closure compound nuclei, resulting in a longer fission time. © Pleiades Publishing, Ltd. 2025.
Surface modification of aligned TiO2 nanotubes by Cu2O nanoparticles and their enhanced photo electrochemical properties and hydrogen generation application
(Elsevier Ltd, 2018) Pawan Kumar Dubey; Rajesh Kumar; Radhey Shyam Tiwari; Onkar Nath Srivastava; Avinash Chandra Pandey; Prabhakar Singh
In this work, we report the synthesis of cuprous oxide (Cu2O) nanoparticles modified vertically oriented aligned titanium dioxide (TiO2) nanotube arrays through wet chemical treatment of TiO2 nanotubes and their multi-functional application as enhanced photo electrochemical and hydrogen generation. The synthesized samples were characterized by X-ray diffraction, SEM, TEM, and UV–Vis spectroscopy. The structural characterization revealed that the admixed Cu2O nanoparticles on the TiO2 surface did not alter its crystalline structure of vertically oriented aligned TiO2 nanotube. The photocatalytic performance and hydrogen generation of as synthesized Cu2O nanoparticles modified aligned TiO2 nanotube was found to highly depend on the Cu2O content. The optical characterizations reveal that the presence of Cu2O nanoparticles extends its absorption into the visible region which improves the photocurrent density in comparison to pristine aligned TiO2 nanotubes electrodes due to enhanced photoactivity and better charge separation. The optimum photocurrent density and hydrogen generation rate has been found to be 3.4 mA cm−2 and 127.5 μmole cm−2 h−1 in 1 M Na2SO4 electrolyte solution under 1.5 AM solar irradiance of white light with illumination intensity of 100 mW cm−2. © 2018 Hydrogen Energy Publications LLC
Synthesis of reduced graphene oxide-TiO2 nanoparticle composite systems and its application in hydrogen production
(Elsevier Ltd, 2014) Pawan Kumar Dubey; Prashant Tripathi; R.S. Tiwari; A.S.K. Sinha; O.N. Srivastava
The utilization of solar energy for the conversion of water to hydrogen and oxygen has been considered to be an efficient strategy to solve crisis of energy and environment. Here, we report the synthesis of reduced graphene oxide-TiO2 nanoparticle composite system through the photocatalytic reduction of graphite oxide using TiO2 nanoparticles. Photoelectrochemical characterizations and hydrogen evolution measurements of these nanocomposites reveal that the presence of graphene enhances the photocurrent density and hydrogen generation rate. The optimum photocurrent density and hydrogen generation rate has been found to be 3.4 mA cm-2 and 127.5 μmole cm-2h-1 in 0.5 M Na2SO4 electrolyte solution under 1.5AM solar irradiance of white light with illumination intensity of 100 mW cm-2. In graphene-TiO2 nanocomposite, photogenerated electrons in TiO2 are scavenged by graphene sheets and percolate to counter electrode to reduce H+ to molecular hydrogen thus increasing the performance of water-splitting reaction. © 2014 Hydrogen Energy Publications, LLC.
Synthesis of self-aligned and vertically oriented carbon incorporated titania nanotube for improved photoelectrochemical hydrogen generation
(Elsevier Ltd, 2017) Pawan Kumar Dubey; Rajesh Kumar; Avinash Chandra Pandey; Radhey Shyam Tiwari; Onkar Nath Srivastava
Photoelectrochemical splitting of water for chemical fuel production utilizing solar energy is regarded as an effective strategy to resolve crisis of energy. Self assembled and highly ordered titanium dioxide nanotube arrays offers considerable interest for hydrogen generation, since ordered structural design of titania nanotubes provides a unidirectional charge transfer channel for electron's transport. Here, we report the hydrogen generation by self assembled and vertically oriented carbon doped titania nanotube array. Carbon doped titania nanotube array photoelectrodes were synthesized by electrochemical method through the anodization of Titanium (Ti) foil in ethylene glycol bath consisting of 0.3 wt.% NH4F and 2 vol.% water by varying the anodization potential and time. The increase in length of carbon doped titania nanotube array increases the efficiency of photo conversion. However very higher lengths of carbon doped titania nanotube array results into decrease in the efficiency mainly due to recombination of charge carriers. The photocurrent density and hydrogen generation rate was found to be 4.0 mAcm−2 and 150 μmol cm−2 h−1 for carbon doped titania nanotube array of lengths 13.5 μm in 1 M NaOH electrolyte solution under 1.5AM solar irradiance of white light with illumination intensity of 100 mWcm−2. © 2016 Hydrogen Energy Publications LLC
Synthesis, crystallographic study, in silico and in vitro investigation of novel flavonol-amino acid conjugate as an anti-proliferative agent
(Elsevier B.V., 2025) Prerna Kumari; Pradeep Harish Kumar; Rakesh Kumar Gupta; Anima Tripathi; Pawan Kumar Dubey; Anuradha Ambasta; Jayhind Kumar Chauhan; Joydeb Goura; Abhijeet Kumar; Garima Tripathi
In this article, a flavonol-Aib conjugate; {(4-oxo-2-phenyl-4-H-chromen-3-yl-2-((start-butoxy-carbonyl) amino)-2-methyl-propanoate) (3A)} has been synthesized, purified and characterized through 1H and 13C NMR, mass spectrometry and X-ray crystallography. X-ray crystallography of these molecules revealed that this is a flavonol-Aib conjugate; there is no intramolecular hydrogen bond, while two intermolecular H-bonds occur between two molecules of flavonol-Aib conjugate, between O2 of C=O (flavonol ring) and H1 (Aib NH) is 2.183Å. This intermolecular interaction generates a stacked two-dimensional (2-D) structure. There are weak interactions between H3 of the flavonol-benzene ring and H18B of the tertiary Butyl-CH3 is 2.804Å., and the same H3 interaction with other molecules' H14 of phenyl of substituted flavonol is 2.332Å. The distance between O2 of C=O (flavonol ring) and H11 (other phenyl-substituted flavonol rings) is 2.610Å, giving a specific molecular conformation. A complete molecular structure investigation of the molecule shows that several inter- and intramolecular weak to strong interactions lead to a peculiar array of molecules in two and three dimensions. In silico studies, molecular docking via Auto doc vina reveals that flavonol with 2-aminoisobutyric acid conjugate, among conjugates of different amino acids (glycine, alanine, valine, leucine, Isoleucine), Aib conjugate shows highest binding affinity with CDC42 (-7.7), BCL2L1 (-8.9), GSK3B (-6.8), MAPK1 (-8.8), PPARG (-7.4), ICAM1 (-7.8), MMP9 (8.0), BCL2 (-8.9), ERBB2 (-9,0), HSP90A1 (9.5) gene. The result of in vitro studies exhibits remarkable inhibitory ability with IC50 values of 400 µg/ml. The overall outcome indicates that flavonol conjugated with 2-aminoisobutyric acid (Aib) can inhibit the growth of the MCF-7 cancer cell line by targeting multiple biological pathways. © 2025
THPM (1,2,3,4-Tetrahydro pyrimidine) and Berberine Exhibit Synergistic Impact on Inhibition of Cell Migration and Colonization Through ROS-Mediated Apoptotic Pathways in the Breast Cancer Cells
(John Wiley and Sons Inc, 2025) Rakesh Kumar Gupta; Ambarish Priyadarshan; Sonal Tiwari; Yashvant Patel; Arun K. Bind; Garima Tripathi; Anima Tripathi; Abhijeet Kumar; Pawan Kumar Dubey
Breast cancer is one of the major causes of death in females worldwide. Considering the polypharmacological trend, small molecules like pyrimidine along with berberine, a bioactive anticancer agent may act as effective anticancer drugs having multiple targets with minimal side effects. However, it has never been tested. The present work discloses the efficacy of the combination of 1,2,3,4,-Tetrahydro pyrimidine (THPM) and Berberine (BBR) in inhibiting cancer progression in human breast cancer cell line, i.e., MCF-7. THPM were synthesized and characterized, and their anti-cancerous potential was evaluated by in silico study. The MCF-7 cells were exposed in vitro with THPM (200 µM), BBR (20 µM/ml) alone or in combination of THPM + BBR (200 µm + 20 µm/ml) for 24 h. Intracellular ROS, annexin-V staining, cell migration, colony formation assay, and gene expression analysis were performed. THPM and BBR both exhibited solid binding affinity against the BCL-2 protein. Interestingly, co-treatment of THPM + BBR significantly increased ROS level, annexin-V positive cells, the expression level of Bax, and Caspase-3 and inhibited migration and proliferation of MCF-7 cells. In conclusion, co-treatment of THPM + BBR exhibits a synergistic impact via inhibiting cell proliferation and inducing ROS-mediated apoptosis in MCF-7 cells suggesting that THPM and BBR could be used as novel therapeutic agents against breast cancer. © 2025 Wiley-VCH GmbH.