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Yadav TP, Kumar A, Verma SK, Mukhopadhyay NK. High-Entropy Alloys for Solid Hydrogen Storage: Potentials and Prospects. Trans Indian Natl Acad Eng 2022; 7:147-156. [PMID: 35837008 PMCID: PMC8742883 DOI: 10.1007/s41403-021-00316-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 12/27/2021] [Indexed: 06/15/2023]
Abstract
Hydrogen storage is one of the most significant research areas for exploiting hydrogen energy economy. To store hydrogen with a high gravimetric/volumetric density, gaseous hydrogen storage systems require a very high-pressure compressed gas cylinder which is quite unsafe and the storage in the liquid form needs cryogenic containers to be maintained at roughly 20 K under ambient pressure because hydrogen has a very low critical temperature of 33 K. However, hydrogen can be stored in solid materials with higher concentration of hydrogen compared to the gaseous and liquid hydrogen storage systems. It is therefore, worthwhile to look into the experimental and theoretical research on prospective hydrogen storage materials. The hydride-forming alloys and intermetallic compounds are found to be the most important families of hydrogen storage materials. Multicomponent alloys consisting of five or more principal elements, also known as high-entropy alloys appear to have potential for the development as hydrogen storage materials. Hydride-forming elements like Ti, Zr, V, Nb, Hf, Ta, La, Ce, Ni, and others have been shown to have hydrogen storage properties and the ability to produce single-phase high-entropy intermetallics. Here, attempts will be made to present a short review on utilization of multicomponent high-entropy alloys as solid hydrogen storage materials. Furthermore, we will also present some of our work on the synthesis, structural-microstructural characterization and hydrogen storage properties of Ti-Zr-V-Cr-Ni equi-atomic hydride-forming high-entropy alloys. From the preliminary investigation, the maximum storage capacity in this system was observed to be 1.78 wt%, which is comparable to other hydrogen storage materials. The prospects of high-entropy-based alloys for hydrogen storage will be discussed.
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Affiliation(s)
- Thakur Prasad Yadav
- Department of Physics, Institute of Science, Hydrogen Energy Centre, Banaras Hindu University, Varanasi, Uttar Pradesh India
| | - Abhishek Kumar
- Department of Physics, Institute of Science, Hydrogen Energy Centre, Banaras Hindu University, Varanasi, Uttar Pradesh India
| | - Satish Kumar Verma
- Department of Physics, Institute of Science, Hydrogen Energy Centre, Banaras Hindu University, Varanasi, Uttar Pradesh India
| | - Nilay Krishna Mukhopadhyay
- Department of Metallurgical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, 221005 India
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Serles P, Arif T, Puthirath AB, Yadav S, Wang G, Cui T, Balan AP, Yadav TP, Thibeorchews P, Chakingal N, Costin G, Singh CV, Ajayan PM, Filleter T. Friction of magnetene, a non-van der Waals 2D material. Sci Adv 2021; 7:eabk2041. [PMID: 34788102 PMCID: PMC8597991 DOI: 10.1126/sciadv.abk2041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Two-dimensional (2D) materials are known to have low-friction interfaces by reducing the energy dissipated by sliding contacts. While this is often attributed to van der Waals (vdW) bonding of 2D materials, nanoscale and quantum confinement effects can also act to modify the atomic interactions of a 2D material, producing unique interfacial properties. Here, we demonstrate the low-friction behavior of magnetene, a non-vdW 2D material obtained via the exfoliation of magnetite, showing statistically similar friction to benchmark vdW 2D materials. We find that this low friction is due to 2D confinement effects of minimized potential energy surface corrugation, lowered valence states reducing surface adsorbates, and forbidden low-damping phonon modes, all of which contribute to producing a low-friction 2D material.
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Affiliation(s)
- Peter Serles
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, ON M5S 3G8, Canada
| | - Taib Arif
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, ON M5S 3G8, Canada
| | - Anand B. Puthirath
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA
| | - Shwetank Yadav
- Department of Materials Science and Engineering, University of Toronto, 184 College St., Toronto, ON M5S 3E4, Canada
| | - Guorui Wang
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, ON M5S 3G8, Canada
| | - Teng Cui
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, ON M5S 3G8, Canada
| | - Aravind Puthirath Balan
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA
- National Graphene Institute (NGI) and School of Chemical Engineering and Analytical Science (CEAS), University of Manchester, Manchester M13 9PL, UK
| | - Thakur Prasad Yadav
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA
- Department of Physics, Institute of Science, Banaras Hindu University, Varanasi 221 005, India
| | | | - Nithya Chakingal
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA
| | - Gelu Costin
- Department of Earth, Environmental and Planetary Sciences, Rice University, Houston, TX 77005, USA
| | - Chandra Veer Singh
- Department of Materials Science and Engineering, University of Toronto, 184 College St., Toronto, ON M5S 3E4, Canada
- Corresponding author. (T.F.); (P.M.A.); (C.V.S.)
| | - Pulickel M. Ajayan
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA
- Corresponding author. (T.F.); (P.M.A.); (C.V.S.)
| | - Tobin Filleter
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, ON M5S 3G8, Canada
- Corresponding author. (T.F.); (P.M.A.); (C.V.S.)
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Huang Y, Zhu G, Zou K, Tian F, Prasad Yadav T, Xu H, Yang G, Li H, Qu L. Highly efficient removal of organic pollutants from wastewater using a recyclable graphene oxide membrane intercalated with g-C3N4@TiO2-nanowires. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116461] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Singh SP, Pritam M, Pandey B, Yadav TP. Microstructure, pathophysiology, and potential therapeutics of COVID-19: A comprehensive review. J Med Virol 2021; 93:275-299. [PMID: 32617987 PMCID: PMC7361355 DOI: 10.1002/jmv.26254] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/14/2020] [Accepted: 06/29/2020] [Indexed: 01/08/2023]
Abstract
There have been over seven million cases and almost 413 372 deaths globally due to the novel coronavirus (2019-nCoV) associated disease COVID-19, as of 11 June 2020. Phylogenetic analysis suggests that there is a common source for these infections. The overall sequence similarities between the spike protein of 2019-nCoV and that of SARS-CoV are known to be around 76% to 78% and 73% to 76% for the whole protein and receptor-binding domain (RBD), respectively. Thus, they have the potential to serve as the drug and/or vaccine candidate. However, the individual response against 2019-nCoV differs due to genetic variations in the human population. Understanding the variations in angiotensin-converting enzyme 2 (ACE2) and human leukocyte antigen (HLA) that may affect the severity of 2019-nCoV infection could help in identifying individuals at a higher risk from the COVID-19. A number of potential drugs/vaccines as well as antibody/cytokine-based therapeutics are in various developmental stages of preclinical/clinical trials against SARS-CoV, MERS-CoV, and 2019-nCoV with substantial cross-reactivity, and may be used against COVID-19. For diagnosis, the reverse-transcription polymerase chain reaction is the gold standard test for initial diagnosis of COVID-19. A kit based on serological tests are also recommended for investigating the spread of COVID-19 but this is challenging due to the antibodies cross-reactivity. This review comprehensively summarizes the recent reports available regarding the host-pathogen interaction, morphological and genomic structure of the virus, and the diagnostic techniques as well as the available potential therapeutics against COVID-19.
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Affiliation(s)
| | - Manisha Pritam
- Amity Institute of BiotechnologyAmity University Uttar PradeshLucknowIndia
| | - Brijesh Pandey
- Department of BiotechnologyMahatma Gandhi Central UniversityMotihariIndia
| | - Thakur Prasad Yadav
- Department of Physics, Institute of ScienceBanaras Hindu UniversityVaranasiIndia
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Yadav TP, Woellner CF, Sharifi T, Sinha SK, Qu LL, Apte A, Mukhopadhyay NK, Srivastava ON, Vajtai R, Galvão DS, Tiwary CS, Ajayan PM. Extraction of Two-Dimensional Aluminum Alloys from Decagonal Quasicrystals. ACS Nano 2020; 14:7435-7443. [PMID: 32469491 DOI: 10.1021/acsnano.0c03081] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Atomically thin metallic alloys are receiving increased attention due to their prospective applications as interconnects/contacts in two-dimensional (2D) circuits, sensors, and catalysts, among others. In this work, we demonstrate an easily scalable technique for the synthesis of 2D metallic alloys from their 3D quasicrystalline precursors. We have used aluminum (Al)-based single-phase decagonal quasicrystal Al66Co17Cu17 alloy to extract the corresponding 2D alloy structure. The 2D layered Al alloy possesses 2-fold decagonal quasicrystalline symmetry and consists of two- or three-layer-thick sheets with a lateral dimension of microns. These 2D metallic layers were combined with the atomic layers of tungsten disulfide to form the stacked heterostructures, which is demonstrated to be a stable and efficient catalyst for hydrogen evolution reaction.
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Affiliation(s)
- Thakur Prasad Yadav
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
- Department of Physics, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | | | - Tiva Sharifi
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
| | - Shyam Kanta Sinha
- Department of Materials Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Lu-Lu Qu
- School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou 221116, People's Republic of China
| | - Amey Apte
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
| | - N K Mukhopadhyay
- Department of Metallurgical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi 221 005, India
| | - O N Srivastava
- Department of Physics, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Robert Vajtai
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
| | - Douglas Soares Galvão
- Applied Physics Department and Center of Computational Engineering and Science, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Chandra Sekhar Tiwary
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
- Department of Metallurgical and Materials Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Pulickel M Ajayan
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
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Shukla V, Bhatnagar A, Singh S, Soni PK, Verma SK, Yadav TP, Shaz MA, Srivastava ON. A dual borohydride (Li and Na borohydride) catalyst/additive together with intermetallic FeTi for the optimization of the hydrogen sorption characteristics of Mg(NH 2) 2/2LiH. Dalton Trans 2019; 48:11391-11403. [PMID: 31282909 DOI: 10.1039/c9dt02270h] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The present study deals with the material tailoring of Mg(NH2)2-2LiH through dual borohydrides: the reactive LiBH4 and the non-reactive NaBH4. Furthermore, a pulverizer, as well as a catalyst FeTi, has been added in order to facilitate hydrogen sorption. Addition of LiBH4 to LiNH2 in a 1 : 3 molar ratio leads to the formation of Li4(BH4)(NH2)3 which also acts as a catalyst. However, the addition of NaBH4 doesn't lead to any compound formation but shows a catalytic effect. The onset dehydrogenation temperature of thermally treated Mg(NH2)2-2LiH/(Li4(BH4)(NH2)3-NaBH4) is 142 °C as against 196 °C for the basic material Mg(NH2)2-2LiH. However, with the FeTi catalyzed Mg(NH2)2-2LiH/(Li4(BH4)(NH2)3-NaBH4, it has been reduced to 120 °C. This is better than other similar amide/hydride composites where it is 149 °C (when the basic material is catalyzed with LiBH4). The FeTi catalyzed Mg(NH2)2-2LiH/(Li4(BH4)(NH2)3-NaBH4 sample shows better de/re-hydrogenation kinetics as it desorbs 3.9 ± 0.04 wt% and absorbs nearly 4.1 ± 0.04 wt% both within 30 min at 170 °C (with the H2 pressure being 0.1 MPa for desorption and 7 MPa for absorption). The eventual hydrogen storage capacity of Mg(NH2)2-2LiH/(Li4(BH4)(NH2)3-NaBH4 together with FeTi has been found to be ∼5.0 wt%. To make the effect of catalysts intelligible, we have put forward in a schematic way the role of Li and Na borohydrides with FeTi for improving the hydrogen sorption properties of Mg(NH2)2-2LiH.
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Affiliation(s)
- Vivek Shukla
- Hydrogen Energy Centre, Department of Physics, Banaras Hindu University, Varanasi-221005, India.
| | - Ashish Bhatnagar
- Hydrogen Energy Centre, Department of Physics, Banaras Hindu University, Varanasi-221005, India.
| | - Sweta Singh
- Hydrogen Energy Centre, Department of Physics, Banaras Hindu University, Varanasi-221005, India. and Department of Physics, School of Physical and Material Sciences, Mahatma Gandhi Central University, Bihar 845401, India
| | - Pawan K Soni
- Hydrogen Energy Centre, Department of Physics, Banaras Hindu University, Varanasi-221005, India.
| | - Satish K Verma
- Hydrogen Energy Centre, Department of Physics, Banaras Hindu University, Varanasi-221005, India.
| | - T P Yadav
- Hydrogen Energy Centre, Department of Physics, Banaras Hindu University, Varanasi-221005, India.
| | - M A Shaz
- Hydrogen Energy Centre, Department of Physics, Banaras Hindu University, Varanasi-221005, India.
| | - O N Srivastava
- Hydrogen Energy Centre, Department of Physics, Banaras Hindu University, Varanasi-221005, India.
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Qu L, Zhu G, Ji J, Yadav TP, Chen Y, Yang G, Xu H, Li H. Recyclable Visible Light-Driven O-g-C 3N 4/Graphene Oxide/N-Carbon Nanotube Membrane for Efficient Removal of Organic Pollutants. ACS Appl Mater Interfaces 2018; 10:42427-42435. [PMID: 30444339 DOI: 10.1021/acsami.8b15905] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Organic pollutants are harmful to human health, which creates a global need for the development of novel and effective materials for efficiently removing contaminants. Accordingly, an efficient visible light-driven heterostructured membrane combined with oxygen-modified monolayer g-C3N4, graphene oxide, and nitrogen-doped carbon nanotubes (CNTs) (O-g-C3N4/GO/N-CNT) was successfully fabricated through electrostatic interactions and subsequent vacuum filtration. The results suggested that the O-g-C3N4/GO/N-CNT membrane exhibited higher degradation rate than those of O-g-C3N4/GO and pure O-g-C3N4 under visible light exposure. This enhanced photocatalytic performance was attributed to the introduction of GO and N-CNT, which acted as electronic acceptors for monolayer O-g-C3N4 that effectively inhibited recombination of photogenerated electron-hole pairs, thus enhancing visible light photocatalytic activity. Furthermore, the enrichment and degradation rates of O-g-C3N4/GO/N-CNT membranes were demonstrated for tetracycline hydrochloride, which were found to be 96.64 and 94.30%, respectively, and no distinct enrichment or catalytic activity reduction was observed when their reusability was measured. These results suggested that these recyclable O-g-C3N4/GO/N-CNT membranes provide a new strategy for the highly efficient removal of environmental pollutants.
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Affiliation(s)
- Lulu Qu
- School of Chemistry and Materials Science , Jiangsu Normal University , Xuzhou 221116 , China
| | - Gen Zhu
- School of Chemistry and Materials Science , Jiangsu Normal University , Xuzhou 221116 , China
| | - Jie Ji
- School of Chemistry and Materials Science , Jiangsu Normal University , Xuzhou 221116 , China
| | - T P Yadav
- Department of Physics, Institute of Science , Banaras Hindu University , Varanasi 221005 , India
| | - Yijiang Chen
- School of Chemistry and Materials Science , Jiangsu Normal University , Xuzhou 221116 , China
| | - Guohai Yang
- School of Chemistry and Materials Science , Jiangsu Normal University , Xuzhou 221116 , China
| | - Hui Xu
- Institute for Energy Research, School of the Environment and Safety Engineering , Jiangsu University , Zhenjiang 212013 , China
| | - Haitao Li
- School of Chemistry and Materials Science , Jiangsu Normal University , Xuzhou 221116 , China
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Qu LL, Wang N, Zhu G, Yadav TP, Shuai X, Bao D, Yang G, Li D, Li H. Facile fabrication of ternary TiO 2-gold nanoparticle-graphene oxide nanocomposites for recyclable surface enhanced Raman scattering. Talanta 2018; 186:265-271. [PMID: 29784359 DOI: 10.1016/j.talanta.2018.04.062] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 04/17/2018] [Accepted: 04/20/2018] [Indexed: 11/26/2022]
Abstract
A bi-functional ternary nanocomposite was developed by decorating TiO2 and gold nanoparticles on the reduced graphene oxide nanosheets (TiO2-Au-rGO) for recyclable surface enhanced Raman scattering (SERS) detection. TiO2-Au-rGO nanocomposites have been shown to demonstrate the superior SERS performances, which can be used for highly sensitive detection of rhodamine 6 G with a limit of detection of 1.2 × 10-10 M. Subsequently, the surface can be cleaned automatically by the photocatalytic degradation of the adsorbed analytes into inorganic small molecules under visible light irradiation. This can be attributed to the excellent photocatalytic degradation ability, leading to a recyclable SERS application. After being used four times, their excellent SERS and catalytic performances can still be retained. These results suggest that the TiO2-Au-rGO nanocomposites can provide a new strategy for fabricating recyclable SERS substrates, which are highly desirable for SERS practical application.
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Affiliation(s)
- Lu-Lu Qu
- School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou 221116, PR China
| | - Na Wang
- School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou 221116, PR China
| | - Gen Zhu
- School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou 221116, PR China
| | - T P Yadav
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA
| | - Xinting Shuai
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA
| | - Dandan Bao
- School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou 221116, PR China
| | - Guohai Yang
- School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou 221116, PR China
| | - Dawei Li
- Shanghai Key Laboratory of Functional Materials Chemistry & College of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
| | - Haitao Li
- School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou 221116, PR China.
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Kajiwara K, Matsui Y, Yadav TP, Mukhopadhyay NK, Srivastava ON. Quasicrystal as a Catalyst for the Synthesis of Carbon Nanotubes. J Nanosci Nanotechnol 2016; 16:3084-3089. [PMID: 27455765 DOI: 10.1166/jnn.2016.12468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The present report describes the catalytic activity of mechanically activated nano quasicrystalline Al65Cu20Fe15 and related nano crystalline Al50Cu28Fe22 for the synthesis of carbon nanotubes (CNTs). CNTs are synthesized by catalytic decomposition of ethanol through nano quasicrystalline Al65Cu20Fe15 and related crystalline Al50Cu28Fe22 alloys as a catalyst. The synthesized multi-walled CNTs exhibits tube diameter ranging from 5 to 25 nm. The synthesized CNTs are characterized by scanning and transmission electron microscopy. It is found that Al65Cu20Fe15 nanoquasicystal shows better catalytic behaviour as compared to nano-crystalline Al50Cu28Fe22 alloys for decomposition of ethanol during the synthesis of multi-walled CNTs.
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Lowe M, Yadav TP, Fournée V, Ledieu J, McGrath R, Sharma HR. Influence of leaching on surface composition, microstructure, and valence band of single grain icosahedral Al-Cu-Fe quasicrystal. J Chem Phys 2015; 142:094703. [PMID: 25747095 DOI: 10.1063/1.4913567] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The use of quasicrystals as precursors to catalysts for the steam reforming of methanol is potentially one of the most important applications of these new materials. To develop application as a technology requires a detailed understanding of the microscopic behavior of the catalyst. Here, we report the effect of leaching treatments on the surface microstructure, chemical composition, and valence band of the icosahedral (i-) Al-Cu-Fe quasicrystal in an attempt to prepare a model catalyst. The high symmetry fivefold surface of a single grain i-Al-Cu-Fe quasicrystal was leached with NaOH solution for varying times, and the resulting surface was characterized by x-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The leaching treatments preferentially remove Al producing a capping layer consisting of Fe and Cu oxides. The subsurface layer contains elemental Fe and Cu in addition to the oxides. The quasicrystalline bulk structure beneath remains unchanged. The subsurface gradually becomes Fe3O4 rich with increasing leaching time. The surface after leaching exhibits micron sized dodecahedral cavities due to preferential leaching along the fivefold axis. Nanoparticles of the transition metals and their oxides are precipitated on the surface after leaching. The size of the nanoparticles is estimated by high resolution transmission microscopy to be 5-20 nm, which is in agreement with the AFM results. Selected area electron diffraction (SAED) confirms the crystalline nature of the nanoparticles. SAED further reveals the formation of an interface between the high atomic density lattice planes of nanoparticles and the quasicrystal. These results provide an important insight into the preparation of model catalysts of nanoparticles for steam reforming of methanol.
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Affiliation(s)
- M Lowe
- Surface Science Research Centre and The Department of Physics, The University of Liverpool, Liverpool L69 3BX, United Kingdom
| | - T P Yadav
- Hydrogen Energy Centre, Department of Physics, Banaras Hindu University, Varanasi 221005, India
| | - V Fournée
- Institut Jean Lamour (UMR7198 CNRS-Université de Lorraine), Parc de Saurupt, 54011 Nancy Cedex, France
| | - J Ledieu
- Institut Jean Lamour (UMR7198 CNRS-Université de Lorraine), Parc de Saurupt, 54011 Nancy Cedex, France
| | - R McGrath
- Surface Science Research Centre and The Department of Physics, The University of Liverpool, Liverpool L69 3BX, United Kingdom
| | - H R Sharma
- Surface Science Research Centre and The Department of Physics, The University of Liverpool, Liverpool L69 3BX, United Kingdom
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Bhutia E, Hemal A, Yadav TP, Ramesh KL. Lipodystrophy syndrome among HIV infected children on highly active antiretroviral therapy in northern India. Afr Health Sci 2014; 14:408-13. [PMID: 25320591 DOI: 10.4314/ahs.v14i2.17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND It is estimated that about 2.5 million people are living with HIV infection in India. Although antiretroviral drugs have been able to reduce the mortality, these drugs have serious side effects one of which is lipodystrophy syndrome. Most of the drugs used in HAART viz, protease inhibitors, stavudine and nevirapine are associated with lipodystrophy. Hence we conducted this study to assess the prevalence of lipodystrophy in HIV infected children on HAART and its associated risk factors. MATERIALS AND METHODS A cross sectional study was conducted on 80 HIV infected children aged 2-18 years of age who were on stavudine based HAART for ≥ 2 years. These children were assessed for presence of lipodystrophy, its metabolic complications and associated risk factors. RESULTS Lipodystrophy was observed in 33.7% of children with lipoatrophy being the commonest subtype followed by lipohypertrophy. Older age, increased duration of treatment and dyslipidaemia were found to be associated in patients with lipodystrophy than those without. On further multivariate analysis of independent risk factors only increased duration of treatment was significantly associated with lipodystrophy. No association was found with insulin resistance. CONCLUSION We observed that lipodystrophy is a common finding in HIV patients treated with HAART for long duration.
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Satija M, Yadav TP, Sachdev N, Chhabra A, Jahan A, Dewan V. Endothelial function, arterial wall mechanics and intima media thickness in juvenile idiopathic arthritis. Clin Exp Rheumatol 2014; 32:432-439. [PMID: 24564946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 12/02/2013] [Indexed: 06/03/2023]
Abstract
OBJECTIVES Juvenile idiopathic arthritis (JIA) is a chronic inflammatory disease of children which might persist into adulthood. Systemic inflammation seen in adult RA patients has been shown to be associated with alteration in endothelial function, arterial wall mechanics and intima media thickness. Our study was planned to assess similar changes in JIA patients. METHODS Thirty-one newly diagnosed JIA patients and a similar number of age- and sex-matched controls were enrolled in the study. Endothelial function was assessed by measuring flow mediated dilation and glyceryl trinitrate (GTN)-mediated dilation of the brachial artery. To assess arterial stiffness, various arterial wall mechanic parameters such as cross-sectional compliance, cross-sectional distensibility, shear stress and elastic modulus were derived. Intima media thickness of the common carotid artery was measured as a marker of subclinical atherosclerosis. RESULTS The brachial artery diameter at rest was found to be slightly lower in the patients than controls (0.258 ± 0.042 vs. 0.264 ± 0.039; p=0.54). No significant difference was found in flow mediated dilation (17.71 ± 9.26 vs. 16.31 ± 8.23; p=0.53), GTN mediated dilation (25.25 ± 10.02 vs. 23.66 ± 9.79; p=0.53) or FMD: GTN mediated dilation ratio (0.730 ± 0.432 vs. 0.717 ± 0.280; p=0.89) between the cases and controls. There was also no significant difference in carotid artery intima media thickness (0.065 ± 0.0068 vs. 0.068 ± 0.007; p=0.084) between cases and controls. Cases in different subsets of JIA were also analysed separately with regards to FMD, GTN mediated dilation and cIMT but no difference was found between cases in each subset and their controls. Cross-sectional compliance was significantly lower in cases than controls (0.0016 ± 0.0005 vs. 0.002 ± 0.001; p=0.034). Cross-sectional distensibility (0.009 ± 0.003 vs. 0.011 ± 0.006; p=0.14) was also found to be lower whereas diastolic wall shear stress (299.9 ± 47.08 vs. 294.9 ± 59.5; p=0.72) and elastic modulus (1138.5 ± 1085.8 vs. 911 ± 453; p=0.19) were found to be higher in cases as compared to controls. But these differences were not statistically significant. When the subsets were analysed separately for vessel wall indices, cross-sectional compliance was found to be significantly lower in systemic arthritis patients as compared to controls. A high level of intra- and inter-observer agreement was found for all the ultrasonographically evaluated parameters. CONCLUSIONS Arterial wall indices were found altered in JIA patients indicating increased arterial stiffness. Larger studies are required to assess endothelial dysfunction, intima media thickness and arterial stiffness in each subset of JIA patients.
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Affiliation(s)
- M Satija
- Department of Pediatrics, Postgraduate Institute of Medical Education and Research, Dr. Ram Manohar Lohia Hospital, New Delhi, India.
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Smerdon JA, Young KM, Lowe M, Hars SS, Yadav TP, Hesp D, Dhanak VR, Tsai AP, Sharma HR, McGrath R. Templated quasicrystalline molecular ordering. Nano Lett 2014; 14:1184-1189. [PMID: 24528205 DOI: 10.1021/nl403947b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Quasicrystals are materials with long-range ordering but no periodicity. We report scanning tunneling microscopy (STM) observations of quasicrystalline molecular layers on 5-fold quasicrystal surfaces. The molecules adopt positions and orientations on the surface consistent with the quasicrystalline ordering of the substrate. Carbon-60 adsorbs atop sufficiently separated Fe atoms on icosahedral Al-Cu-Fe to form a unique quasicrystalline lattice, whereas further C60 molecules decorate remaining surface Fe atoms in a quasi-degenerate fashion. Pentacene (Pn) adsorbs at 10-fold symmetric points around surface-bisected rhombic triacontahedral clusters in icosahedral Ag-In-Yb. These systems constitute the first demonstrations of quasicrystalline molecular ordering on a template.
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Affiliation(s)
- J A Smerdon
- Jeremiah Horrocks Institute for Mathematics, Physics and Astronomy, University of Central Lancashire , Fylde Rd, Preston, Lancashire PR1 2HE, United Kingdom
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Bhatt GC, Dewan V, Dewan T, Yadav TP. Pseudotumour cerebri with multiple cranial nerve palsies in enteric fever. Indian J Pediatr 2014; 81:196-7. [PMID: 23334586 DOI: 10.1007/s12098-013-0965-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 01/08/2013] [Indexed: 11/26/2022]
Affiliation(s)
- Girish Chandra Bhatt
- Department of Pediatrics, PGIMER and Associated Dr RML Hospital, New Delhi, India
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Manandhar KD, Yadav TP, Prajapati VK, Basukala O, Aganja RP, Dude A, Shrivastav ON, Sundar S. Nanonization increases the antileishmanial efficacy of amphotericin B: an ex vivo approach. Adv Exp Med Biol 2014; 808:77-91. [PMID: 24595612 DOI: 10.1007/978-81-322-1774-9_7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
With widespread resistance to pentavalent antimonial in the endemic eastern terai belt of Nepal and Bihar, India, Amphotericin B deoxycholate is now the first-line antileishmanial drug for the treatment of visceral leishmaniasis (VL). However, universal occurrence of infusion-related fever and rigors with amphotericin B (AmB), occasional serious life-threatening toxicities like cardiotoxicity, anaphylaxis, hypokalemia, and nephrotoxicity are major barriers to its use in areas with limited medical facilities. Liposomal amphotericins, however, are devoid of adverse effects, high cost makes it unaffordable. We had formulated nanoparticles (10-20 nm) from amphotericin B deoxycholate (1-2 μm) applying high pressure (150 atm) milling homogenization in argon atmosphere and tested its ex vivo efficacy in Leishmania infected J774A cell line and peritoneal macrophage. The ex vivo ED50 for intracellular amastigotes in peritoneal macrophage by nano-amphotericin was 0.0027 ± 0.001 μg/mL which was significantly less (p = 0.0029) than the required dose of amphotericin B (0.0426 ± 0.003 μg/mL). Similarly, in J774A cell line, 50 % of intracellular amastigotes were cleared by 0.0038 ± 0.001 μg/mL of nano-amphotericin while the dose was a bit more for AmB (0.0196 ± 0.001 μg/mL) illustrating the significant difference (p value, 0.0122). The nanoformulation has also shown high efficacy (ED50, 0.0028-0.0035 μg/mL) in inhibition of infected macrophage count. The new formulation accumulated to spleen, the targeted organ, 7 days after inoculation of drug to the infected hamster as traced in vivo by TEM convincing it as potential drug. Given a favorable safety profile and very low cost of production contemplated, it may prove to be a feasible alternative for conventional amphotericin B.
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Affiliation(s)
- Krishna Das Manandhar
- Central Department of Biotechnology, Institute of Science and Technology, Tribhuvan University, Kathmandu, Nepal,
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Tamura R, Yadav TP, McLeod IM, Hesp D, Young KM, Nakamura T, Nishio K, Dhanak VR, McGrath R, Sharma HR. Scanning tunneling microscopy of a polygrain Al–Pd–Re quasicrystal: study of the relative surface stability. J Phys Condens Matter 2013; 25:395007. [PMID: 24018417 DOI: 10.1088/0953-8984/25/39/395007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Scanning tunneling microscopy and x-ray photoemission spectroscopy on a polygrain icosahedral (i-) Al–Pd–Re quasicrystal (QC) show the formation of the twofold surfaces with symmetry and composition expected from the bulk. The predominant occurrence of the twofold surface on the polygrain i-QC having random grain orientation, as well as preferential formation of terrace edges, kinks and voids along the twofold axes, consistently indicates that the twofold surface, which has the highest atomic density, is the most stable among all the crystallographic planes.
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Abstract
Tuberculous liver abscess without active pulmonary or miliary tuberculosis or other clinical evidence of tuberculosis, is very rare. A 3-year-old immunocompetent boy with isolated tuberculous liver abscess recovered completely on systemic anti-tuberculous drugs.
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Affiliation(s)
- Devki Nandan
- Postgraduate Institute of Medical Education and Research and Associated Dr RML Hospital, New Delhi, India
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Yadav A, Yadav TP. A study of school adjustment, self-concept, self-esteem, general wellbeing and parent child relationship in Juvenile Idiopathic Arthritis. Indian J Pediatr 2013; 80:199-206. [PMID: 22766902 DOI: 10.1007/s12098-012-0804-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 05/24/2012] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To assess school adjustment, self-concept, self-esteem, general wellbeing and parent-child relationship in children with Juvenile Idiopathic Arthritis (JIA)and to study the correlation of these parameters with chronicity of disease, number of active joints, laboratory parameters of disease activity and JIA subtypes. METHODS A total of 64 children (32 cases and 32 controls) were recruited for analysis. Self report questionnaires which included PGI General Wellbeing Measure, Adjustment Inventory for School Students, Parent Child Relationship Scale, Self Esteem Inventory and Self Concept Questionnaires were used to assess all the enrolled subjects. RESULTS Cases had significantly lower general physical well being (p < 0.001), self- esteem (p = 0.039), social self-concept (p = 0.023) and poorer social (p = 0.002), educational (p = 0.002) and overall (p = 0.006) adjustment as compared to controls. Both parents of cases were significantly more demanding (p = 0.028, p = 0.004)and mothers were over protective (p = 0.009) and pampering with object rewards (p = 0.02). PGI wellbeing score (p = 0.042, p = 0.019) and self concept (p = 0.002, for social SCQ p = 0.030) correlated well with number of active joints and ESR. As the disease duration increased, fathers tended to neglect their children (p = 0.043) and with persistent disease activity (reflected by CRP positivity) even resorted to punishment (p = 0.022) or remained indifferent (p = 0.048). CONCLUSIONS JIA significantly hampers the child's self-esteem, self-concept, adjustment in school, general wellbeing and evokes disturbed parent-child relationship.
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Affiliation(s)
- Anita Yadav
- Department of Pediatrics, PGIMER, Dr Ram Manohar Lohia Hospital, New Delhi, India
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Prasad Yadav T, Manohar Yadav R, Pratap Singh D. Mechanical Milling: a Top Down Approach for the Synthesis of Nanomaterials and Nanocomposites. ACTA ACUST UNITED AC 2012. [DOI: 10.5923/j.nn.20120203.01] [Citation(s) in RCA: 320] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Prajapati VK, Awasthi K, Yadav TP, Rai M, Srivastava ON, Sundar S. An oral formulation of amphotericin B attached to functionalized carbon nanotubes is an effective treatment for experimental visceral leishmaniasis. J Infect Dis 2011; 205:333-6. [PMID: 22158723 DOI: 10.1093/infdis/jir735] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Amphotericin B (AmB), is a highly effective antileishmanial agent used as first-line treatment in different formulations in visceral leishmaniasis endemic areas of Bihar, India. However, parenteral infusion, prolonged hospitalization, and toxicity are major hurdles. Our previous work demonstrated the efficacy and stability of functionalized carbon nanotubes as a delivery mechanism for AmB. In this study, using the hamster model, we have shown that this novel formulation of AmB can be administered orally, resulting in 99% inhibition of parasite growth following a 5-day course at 15 mg/kg body weight.
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Affiliation(s)
- Vijay Kumar Prajapati
- Department of Medicine, Infectious Disease Research Laboratory, Institute of Medical Sciences, Banaras Hindu University,Varanasi, India
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Gupta V, Gupta P, Yadav TP. Transfusion related acute lung injury with intravenous immunoglobulin. Indian Pediatr 2011; 48:807-808. [PMID: 22080684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This case report describes transfusion related acute lung injury with the use of intravenous immunoglobulin in a child with Guillain barre syndrome.
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Affiliation(s)
- V Gupta
- Department of Pediatrics and Neonatology, PGIMER and associate Dr Ram Manohar Lohia Hospital, New Delhi, India
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Prajapati VK, Awasthi K, Gautam S, Yadav TP, Rai M, Srivastava ON, Sundar S. Targeted killing of Leishmania donovani in vivo and in vitro with amphotericin B attached to functionalized carbon nanotubes. J Antimicrob Chemother 2011; 66:874-9. [PMID: 21393222 DOI: 10.1093/jac/dkr002] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES This study describes the antileishmanial efficacy of the novel drug formulation of amphotericin B (AmB) attached to functionalized carbon nanotubes (f-CNTs) and compares it with AmB. METHODS f-CNTs were prepared in a two-step chemical carboxylation and amidation process. The AmB was then attached to make f-CNT-AmB and its construction was confirmed by Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM). The cytotoxicity of the constructed compound, f-CNT-AmB, was assessed in vitro using the J774A.1 macrophage cell line and in vivo using healthy BALB/c mice. Antileishmanial activity of AmB and f-CNT-AmB was assessed in vitro using a macrophage (J774A.1 cell line) model of Leishmania donovani infection. Antileishmanial activity was assessed in vivo by comparing the parasite load of hamsters treated with a 5 day course of AmB, f-CNTs or f-CNT-AmB initiated at 30 days after infection with L. donovani parasites. RESULTS The FTIR spectroscopy and TEM data demonstrate the successful attachment of AmB to f-CNTs. The in vitro cytotoxicity of AmB, f-CNTs and f-CNT-AmB was measured by the cytotoxic concentration required to kill 50% of the cells: 0.48±0.06 μg/mL; 7.31±1.16 μg/mL; 0.66±0.17 μg/mL, respectively, in the J774A.1 cell line. The in vivo toxicity assessment of the compounds in BALB/c mice revealed no hepatic or renal toxicity. Against intracellular amastigotes the in vitro antileishmanial efficacy of f-CNT-AmB was significantly higher than that of AmB (IC50 0.00234±0.00075 μg/mL versus 0.03263±0.00123 μg/mL; P≤0.0001). The percentage inhibition of amastigote replication in hamsters treated with f-CNT-AmB was significantly more than that with AmB (89.85%±2.93% versus 68.97%±1.84%; P=0.0004). CONCLUSIONS The results of these experiments clearly demonstrate that f-CNT-AmB has significantly greater antileishmanial efficacy than AmB and had no significant cytotoxic effects.
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Affiliation(s)
- Vijay Kumar Prajapati
- Infectious Disease Research Laboratory, Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221 005, India
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Tiwari RS, Yadav TP, Mukhopadhyay NK, Shaz MA, Srivastava ON. Nanocrystallization and structural correlation in quasicrystalline and crystalline phases during mechanical milling. Z KRIST-CRYST MATER 2009. [DOI: 10.1524/zkri.2009.1068] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
The main objective of the proposed work is to investigate the formation of nanoquasicrystalline and related nanocrystalline phases in Al—Cu—Fe system during mechanical milling at the initial stage of milling. The mechanical milling of a quasicrystalline Al65Cu20Fe15 alloy was performed in a high-energy ball mill (Szegvari attritor) by varying milling time from 2.5 min to 60 min under liquid hexane medium at the speed of 400 rpm with a ball to powder ratio of 40 : 1. X-ray diffraction was carried out for evaluating the lattice strain, lattice parameters and crystallite sizes of the milled sample. It was found that the evolution of monoclinic Al13Fe4 phase from Al65Cu20Fe15 quasicrystalline phase occurred after 2.5 min of milling, which was further confirmed by transmission electron microscopy. After 5 min of ball milling nano size disordered B2 phase (bcc, a = 0.29 nm) was also found. The systematic analysis of the XRD patterns for evolving lattice parameter, sequential strain suggests that the lattice strain during milling has been quite considerable.
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Yadav TP, Mukhopadhyay NK, Shaz MA, Tiwari RS, Srivastava ON. Formation of nano-quasicrystalline decagonal phase in the Al70Cu10Co5Ni15 system by high energy ball milling. J Nanosci Nanotechnol 2009; 9:5527-5532. [PMID: 19928257 DOI: 10.1166/jnn.2009.1130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A nano decagonal quasicrystalline phase in the Al70Cu10Co5Ni15 alloy has been synthesized by mechanical alloying of a mixture of elemental powders followed by annealing. A high-energy ball milling of the elemental mixture of Al, Cu, Co and Ni leads to the formation of B2 type quaternary intermetallic alloys. The X-ray diffraction and transmission electron microscopy techniques have been employed for characterization of the samples. It was observed that the dissolution of the individual elements into an alloy led to the formation of a nano B2 phase. This phase was found to be quite stable against milling and no other crystalline or amorphous phases could be detected. Milled powder after annealing at 700 degrees C for 60 h was found to transform to nano-decagonal phase. Attempts have been made to understand the evolution of the complex intermetallic nano phases and their relative stability during milling.
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Affiliation(s)
- T P Yadav
- Department of Physics, Banaras Hindu University, Varanasi 221005, India
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Manandhar KD, Yadav TP, Prajapati VK, Kumar S, Rai M, Dube A, Srivastava ON, Sundar S. Antileishmanial activity of nano-amphotericin B deoxycholate. J Antimicrob Chemother 2008; 62:376-80. [PMID: 18453526 DOI: 10.1093/jac/dkn189] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES The aim of the present study was to compare the efficacy of a nano form of amphotericin B deoxycholate with that of conventional amphotericin B deoxycholate for the treatment of visceral leishmaniasis. METHODS We have formulated nanoparticles (10-20 nM) from amphotericin B deoxycholate (1-2 microM) by applying high-pressure (150 argon) milling homogenization and have tested their efficacy in a J774A cell line and in hamsters. Parasite survival and tissue burden in spleen were evaluated for nano-amphotericin B and conventional amphotericin B. Both nano-amphotericin B and conventional amphotericin B were injected intraperitoneally at 5 mg/kg per day for 5 days. RESULTS The inhibition of amastigotes in the splenic tissue with nano-amphotericin B was significantly more than with conventional amphotericin B (92.18% versus 74.57%, P = 0.005). Similarly, the suppression of parasite replication in the spleen was also found to be significant (99.18% versus 97.17%, P = 0.05). In a cytotoxicity test, nano-amphotericin B against the J774A cell line had a CC(50) of 12.67 mg/L in comparison with 10.61 mg/L for amphotericin B, far higher than the doses used for ED(50). CONCLUSIONS Nanoparticles of amphotericin B had significantly greater efficacy than conventional amphotericin B. This formulation may have a favourable safety profile, and if production costs are low, it may prove to be a feasible alternative to conventional amphotericin B.
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Affiliation(s)
- Krishna Das Manandhar
- Infectious Disease Research Laboratory, Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221 005, India
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Yadav TP, Mukhopadhyay NK, Tiwari RS, Srivastava ON. Synthesis of nanocrystalline (Co, Ni)Al2O4 spinel powder by mechanical milling of quasicrystalline materials. J Nanosci Nanotechnol 2007; 7:575-9. [PMID: 17450798 DOI: 10.1166/jnn.2007.128] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
In the present study, attempts have been made to synthesize the nano-crystalline (Co, Ni)Al2O4 spinel powders by ball milling and subsequent annealing. An alloy of Al70Co15Ni15, exhibiting the formation of a complex intermetallic compound known as decagonal quasicrystal is selected as the starting material for mechanical milling. It is interesting to note that this alloy is close to the stoichiometry of aluminum and transition metal atoms required to form the aluminate spinel. The milling was carried out in an attritor mill at 400 rpm for 40 hours with ball to powder ratio of 20 : 1 in hexane medium. Subsequent to this annealing was performed in an air ambience for 10, 20, and 40 h at 600 degrees C in side the furnace in order to oxidize the decagonal phase and finally to form the spinel structure. The X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the formation of nano-sized decagonal phase after milling and then (Co, Ni)Al2O4 spinel type phase after annealing. The XRD studies reveal the lattice parameter to be 8.075 angstroms and the lattice strain as 0.6%. The XRD and TEM explorations of spinel phase indicate the average grain size to be approximately 40 nm.
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Affiliation(s)
- T P Yadav
- Department of Physics, Banaras Hindu University, Varanasi 221005, India
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Abstract
Reactive proliferation and inappropriate activation of mature histiocytes with haemophagocytosis (HP) may occur in association with a wide variety of infections, neoplasms, collagen vascular diseases, and acquired and inherited immunodeficiency states. The association with infections is particularly important because overwhelming HP can obscure the typical clinical features of the primary disease and negatively affects outcome. A high index of suspicion is required for early recognition of associated HP as the cause of cytopenias. Institution of specific therapy is crucial for survival. This study highlights the wide spectrum of tropical diseases that can have associated reactive HP. Thirty cases with documented prominent HP on bone marrow aspiration smears were reviewed. Twenty-one (69%) of the marrows were from patients who had common tropical infections: malaria, typhoid and visceral leishmaniasis and 11 of 15 patients (73%) who were followed up improved on specific infection-directed and supportive measures. The presence of severe HP in bone marrow smears correlated with marked cytopenias. Recognition of HP in this geographical region should stimulate the search for one of these infections as early institution of specific therapy is crucial for patient survival.
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Affiliation(s)
- Z N Singh
- Department of Pathology, Maulana Azad Medical College, New Delhi, India
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Yadav TP, Singh R, Yadav R, Bhardwaj M, Satyanarayana L. Role of cetirizine in treatment of eosinophilia. Indian Pediatr 2000; 37:1098-101. [PMID: 11042709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Affiliation(s)
- T P Yadav
- Department of Pediatrics, Dr. Ram Manohar Lohia Hospital, New Delhi 110 011, India
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Yadav TP, Bhardwaj M, Aggarwal S, Mohan B, Ndeswari A. Mediastinal enteric cyst infected with Salmonella typhi. Indian Pediatr 2000; 37:667-70. [PMID: 10869152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Affiliation(s)
- T P Yadav
- Department of Pediatrics, Dr. Ram Manohar Lohia Hospital, New Delhi 110 001, India
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Abstract
BACKGROUND The study stemmed from an incidental observation of improvement in 2 patients with pityriasis rosea while receiving erythromycin. OBJECTIVE The purpose of the study was to evaluate the efficacy of erythromycin in patients with pityriasis rosea. METHODS A double-blind, placebo-controlled clinical study was performed in an outpatient setting in a major hospital. Ninety patients over a period of 2 years were alternatively assigned to treatment group or placebo group. Patients in the treatment group received erythromycin in divided doses for 14 days. The response was categorized as complete response, partial response, or no response. All patients were followed up for 6 weeks. RESULTS Both groups were comparable with regard to age at presentation, sex, and average duration of disease at the time of reporting to the clinic. Upper respiratory tract infection before the appearance of skin lesions was reported in 68.8% of all patients. Complete response was observed in 33 patients (73.33%) in the treatment group and none in the placebo group (P <.0001). CONCLUSION Oral erythromycin was effective in treating patients with pityriasis rosea.
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Affiliation(s)
- P K Sharma
- Department of Dermatology, Dr Ram Manohar Lohia Hospital, New Delhi, India
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Yadav TP, Singh RP, Gautam RK. Multiple lentigines: a case with new associations. Indian Pediatr 1999; 36:827-9. [PMID: 10742741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Affiliation(s)
- T P Yadav
- Departments of Pediatrics and Dermatology, Dr. Ram Monohar Lohia Hospital, New Delhi, India
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Yadav TP, Singh RP, Gupta VK, Chaturvedi NK, Prasad CV. Paravertebral extraosseous Ewing's sarcoma. Indian Pediatr 1998; 35:557-60. [PMID: 10216655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Affiliation(s)
- T P Yadav
- Department of Pediatrics, Dr. Ram Manohar Lohia Hospital, New Delhi
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Yadav TP, Mishra S, Sachdeva KJ, Gupta VK, Siddhu KK, Bakshi G, Yadav RB. Pancytopenia in disseminated tuberculosis. Indian Pediatr 1996; 33:597-9. [PMID: 8979574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- T P Yadav
- Department of Pediatrics, Dr. Ram Manohar Lohia Hospital, New Delhi
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37
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Affiliation(s)
- R K Gautam
- Department of Dermatology, Dr. Ram Manohar Lohia Hospital, New Delhi, India
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38
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Mishra S, Yadav TP, Nangia S, Gupta VK, Sidhu KK. Vitamin-D dependent rickets type II. Indian Pediatr 1996; 33:334-6. [PMID: 8772913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- S Mishra
- Department of Pediatrics, Dr. Ram Manohar Lohia Hospital, New Delhi
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39
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Yadav TP. Wolman's disease. Indian Pediatr 1995; 32:1324. [PMID: 8772896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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40
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Yadav TP, Gupta VK, Mishra S, Gautam RK, Sharma PK. Hereditary onycho-osteo dysplasia syndrome. Indian J Dermatol Venereol Leprol 1995; 61:360-362. [PMID: 20953024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We report a two and a half year old male child with dystrophy of all the nails, absent patellae and iliac horns. In addition he had dysmorphic facial features, sparing of lunula and bilateral hallux valgus deformity, hitherto not reported earlier.
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Affiliation(s)
- T P Yadav
- Departments of Paediatrics, Dr Ram Manohar Lohia Hospital, New Delhi-110001, India
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41
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Yadav TP, Mishra S, Gautam RK. Keloid at the venipuncture site. Indian Pediatr 1995; 32:1243-4. [PMID: 8772879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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42
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Yadav TP, Mazid MP, Mishra S, Gupta VK, Gautam RK. Urticaria--an unusual presentation of staphylococcemia. Indian Pediatr 1995; 32:1005-7. [PMID: 8935267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- T P Yadav
- Department of Pediatrics, Dr. Ram Manohar Lohia Hospital, New Delhi
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43
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Yadav TP, Mishra S, Gupta VK, Gautam RK, Kar HK, Bhardwaj M. Odontotrichodysplasia: a case report with a review of conditions combining ectodermal dysplasia (subgroup 1-2) with skin manifestations. J Dermatol 1995; 22:606-10. [PMID: 7560461 DOI: 10.1111/j.1346-8138.1995.tb03883.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We report a 5-year-old girl with partial anodontia, hypotrichosis, hyperpigmentation of the skin, absence of pilosebaceous structures, and long thin fingers. There has as yet been, to the best of our knowledge, no report of such a combination of features. A review of conditions combining ectodermal dysplasia (subgroup 1-2) with skin manifestations is presented.
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Affiliation(s)
- T P Yadav
- Department of Paediatrics, Dr. Ram Manohar Lohia Hospital, New Delhi, India
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44
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Yadav TP, Gupta VK, Khanna R, Avtar K, Mishra S. Calcification in renal tuberculosis. Indian Pediatr 1995; 32:581-5. [PMID: 8613319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- T P Yadav
- Department of Pediatrics, Dr. Ram Manohar Lohia Hospital, New Delhi
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45
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Gupta VK, Yadav TP, Khanna R, Avtar K, Mishra S. Hereditary pancreatitis with lithiasis in a 7-year-old boy. Indian Pediatr 1995; 32:111-5. [PMID: 8617523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- V K Gupta
- Department of Pediatrics, Dr. Ram Manohar Lohia Hospital, New Delhi
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46
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Abstract
An 11-month-old male infant was admitted to hospital with fever, pallor and hepatosplenomegaly, and was diagnosed as having kala-azar. The mother also suffered from kala-azar while carrying this baby. As the baby and the mother did not leave Delhi either during or after delivery, and the vector found in Delhi is not competent to transmit leishmaniasis, the infant could not have been infected by the bite of a sandfly. It therefore seems most likely that he was infected in utero--a rare route.
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Affiliation(s)
- T P Yadav
- Department of Paediatrics, Dr. R. M. L. Hospital, New Delhi, India
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Bhatia S, Ray K, Mathur R, Yadav TP, Rai Chowdhary AN, Grover SS, Narayanan I. Evaluation of cutaneous response to tetanus antigen to document immunization: preliminary observations. Indian Pediatr 1985; 22:267-73. [PMID: 3833747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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