34 research outputs found
Physiological evaluation of nitrogen use efficiency and yield attributes in rice (Oryza sativa L.) genotypes under different nitrogen levels
Nitrogen use efficiency, more specifically physiological nitrogen use efficiency depends primarily on management of N, one of the major essential nutrients. It is required in increased agricultural production and may possibly cause soil toxicity if fed in excess. Rate of N fertilizer application in fertile agricultural field and improved productivity in sterile soils require the improvement of NUE. A field experiment was therefore conducted to evaluate the effect of different N levels (N0, N50, N100 and N200) on rice genotypes. Vegetative plant growth was found to be reduced under N0 while improved at N200 level. Among the genotypes, highest PNUE (34.94) and correspondingly higher yield (7.15 ton ha−1) was observed for Krishna Hamsa. The other traits viz. plant height, no. of productive tillers and LAI exhibited higher values for Krishna Hamsa as well. Hence these can be utilized as physiological markers for the selection of rice genotypes efficient in N use
Colorimetric Estimation of Ni(II) Ions in Aqueous Solution
A rapid and accurate colorimetric method has been proposed for the estimation of nickel(II) in aqueous solution. It is found that nickel(II) ions have maximum absorbance at 393 nm in distilled water and in aqueous sucrose solution (0.3 mol dm-3). In both case, the Beer’s law was obeyed over the range from 0.04 to 0.08 mol dm -3 of nickel(II).The value of molar absorpitivity was constant 5.13±0.03 mol dm-3. This method is more rapid than the existing spectrophotometeric methods for the estimation of nickel(II). The variation in the results obtained by the method is ±2.1%
Enrichment of <sup>65</sup>Zn in two contrasting rice genotypes under varying methods of zinc application
Optical limiting applications of resonating plasmonic Au nanoparticles in a dielectric glass medium
Abstract
Plasmonic nanostructures exhibiting high optical nonlinearities are widely used in the rapidly growing modern nanotechnology of nonlinear optics including biomedical applications due to their tunable plasmonic behavior. In this work, we investigate the nonlinear optical properties of uniformly distributed Au nanoparticles (NPs) embedded in pre-synthesized sodium−zinc borate glass by the well-known ion-exchange technique for optical limiting (OL) applications. Various techniques such as optical absorption spectroscopy, x-ray photoelectron spectroscopy, Transmission Electron Microscope (TEM), Photoluminescence, Time of Flight secondary mass spectroscopy and the Z scan technique were used for the characterization of these NPs. TEM confirmed spherically shaped Au NPs with varying sizes of up to 16 nm, in agreement with optical absorption spectroscopy. Nonlinear optical (NLO) properties of these Au NPs were investigated by using an open as well as close aperture Z scan technique which exhibited enhanced optical nonlinearities. The two-photon absorption (2PA) coefficients demonstrated an increasing trend while the OL threshold values demonstrated a decreasing trend as a function of heat treatment. The improved 2PA coefficients and decreased OL threshold values endorsed the Au NPs containing glasses as contending materials for the fabrication of promising optical limiters for the protection of eyes and other sensitive instruments from laser induced damages.</jats:p
Defects induced enhancement of antifungal activities of Zn doped CuO nanostructures
CuO nanostructures doped with different concentration of Zn have been synthesized by a simple low-cost combustion method. The prepared samples have been tested by the various techniques such as X-ray diffraction (XRD), Transmission Electron Microscope (TEM), Optical absorption spectroscopy, Photoluminescence, and X-ray photoelectron spectroscopy (XPS). XRD confirmed the presence of the monoclinic phase of CuO along with an extra ZnO phase in the CuO:Zn. TEM results confirmed almost spherical - shaped nanoparticles as well as some irregular shaped NPs for pure CuO and Zn doped CuO with the average size from 24 to 55 nm. The change in morphology revealed a structural change in the CuO:Zn crystal due to different concentration of the Zn. The chemical study was done by XPS and the results were also correlated with XRD based results. The role of localized defects was compared and interpreted for the change in the luminescence spectral bands, micro-stains and oxidation states of the CuO:Zn for the different concentrations. CuO:Zn nanostructures demonstrated significant antifungal activities against two South African plant pathogens, Alternaria alternata CGJM3078 and Alternaria alternate CGJM3006, in comparison to pure CuO samples. The result showed that the pure and Zn doped CuO samples could be used as a good antifungal agent that could have an extensive applications in the agricultural and biotechnological industries
Optical limiting applications of resonating plasmonic Au nanoparticles in a dielectric glass medium
Plasmonic nanostructures exhibiting high optical nonlinearities are widely used in the rapidly growing modern nanotechnology of nonlinear optics including biomedical applications due to their tunable plasmonic behavior. In this work, we investigate the nonlinear optical properties of uniformly distributed Au nanoparticles (NPs) embedded in pre-synthesized sodium-zinc borate glass by the well-known ion-exchange technique for optical limiting (OL) applications. Various techniques such as optical absorption spectroscopy, x-ray photoelectron spectroscopy, Transmission Electron Microscope (TEM), Photoluminescence, Time of Flight secondary mass spectroscopy and the Z scan technique were used for the characterization of these NPs. TEM confirmed spherically shaped Au NPs with varying sizes of up to 16 nm, in agreement with optical absorption spectroscopy. Nonlinear optical (NLO) properties of these Au NPs were investigated by using an open as well as close aperture Z scan technique which exhibited enhanced optical nonlinearities. The two-photon absorption (2PA) coefficients demonstrated an increasing trend while the OL threshold values demonstrated a decreasing trend as a function of heat treatment. The improved 2PA coefficients and decreased OL threshold values endorsed the Au NPs containing glasses as contending materials for the fabrication of promising optical limiters for the protection of eyes and other sensitive instruments from laser induced damages
Integrated machine learning and chemoinformatics-based screening of mycotic compounds against kinesin spindle proteinEg5 for lung cancer therapy
Among the various types of cancer, lung cancer is the second most-diagnosed cancer worldwide. The kinesin spindle protein, Eg5, is a vital protein behind bipolar mitotic spindle establishment and maintenance during mitosis. Eg5 has been reported to contribute to cancer cell migration and angiogenesis impairment and has no role in resting, non-dividing cells. Thus, it could be considered as a vital target against several cancers, such as renal cancer, lung cancer, urothelial carcinoma, prostate cancer, squamous cell carcinoma, etc. In recent years, fungal secondary metabolites from the Indian Himalayan Region (IHR) have been identified as an important lead source in the drug development pipeline. Therefore, the present study aims to identify potential mycotic secondary metabolites against the Eg5 protein by applying integrated machine learning, chemoinformatics based in silico-screening methods and molecular dynamic simulation targeting lung cancer. Initially, a library of 1830 mycotic secondary metabolites was screened by a predictive machine-learning model developed based on the random forest algorithm with high sensitivity (1) and an ROC area of 0.99. Further, 319 out of 1830 compounds screened with active potential by the model were evaluated for their drug-likeness properties by applying four filters simultaneously, viz., Lipinski’s rule, CMC-50 like rule, Veber rule, and Ghose filter. A total of 13 compounds passed from all the above filters were considered for molecular docking, functional group analysis, and cell line cytotoxicity prediction. Finally, four hit mycotic secondary metabolites found in fungi from the IHR were screened viz., (−)-Cochlactone-A, Phelligridin C, Sterenin E, and Cyathusal A. All compounds have efficient binding potential with Eg5, containing functional groups like aromatic rings, rings, carboxylic acid esters, and carbonyl and with cell line cytotoxicity against lung cancer cell lines, namely, MCF-7, NCI-H226, NCI-H522, A549, and NCI H187. Further, the molecular dynamics simulation study confirms the docked complex rigidity and stability by exploring root mean square deviations, root mean square fluctuations, and radius of gyration analysis from 100 ns simulation trajectories. The screened compounds could be used further to develop effective drugs against lung and other types of cancer
Plasmonic Au nanoparticles embedded in glass: Study of TOF-SIMS, XPS and its enhanced antimicrobial activities
The Au nanoparticles (NPs) were formed near the surfaces of pre-synthesized sodium zinc -borate glass by an ion exchange process obtained by thermal heat treatment in an open air environment at various temperatures. The pre-heated Au doped glass samples were extensively tested by the different techniques such as optical absorption spectroscopy, Scanning Electron Microscope (SEM), X-ray photoelectron spectroscopy (XPS), Time of Flight Secondary Ion Mass Spectroscopy (TOF-SIMS), and these Au NPs were used for the antimicrobial applications. SEM confirmed the spherical shaped Au NPs with increasing thermal treatment up to 550 degrees C. The optical absorption findings showed that the as -synthesized Au NPs showed Localized Surface Plasmon Resonance behaviour, giving clear evidence of an Au NPs band formed in the glass matrix. The formation mechanism of the Au doped glass samples was studied theoretically from a thermodynamic point of view during heat treatment. XPS and TOF-SIMS were used to study the chemical state and the thermal stability of the pre-heated Au NPs doped glasses in an ultra-high vacuum. The effect of concentration changes in the line-shape and in binding energy as a function of thermal heat treatment suggests that the Au NPs formed near the glass surfaces and changes in the chemical composition as well as chemical structures of the Au doped glass samples occurred. Antimicrobial activity such as antibacterial as well as antifungal activity of pre-heated Au doped glass samples was tested against different strains by the disk diffusion method. The Au doped glass samples exhibited enhanced antibacterial as well as antifungal activities by the influence of thermal treatment at different temperatures. Thus, the Au doped glass sample could be efficiently explored as a medical tool in pharmaceutical industries, biotechnology industries and chemical laboratories based upon its antibacterial findings
Growth and vacuum post-annealing effect on the structural, electrical and optical properties of Sn-doped In2O3 thin films
Nowadays, the fabrication of cheaper, thermodynamically stable and durable transparent semiconducting oxide-based thin films are on high demand to enhance the properties of optoelectronic, sensing and energy harvesting devices. It is well known that Sn-doped In2O3 (ITO) thin films are difficult to grow by direct current sputtering. However, in this work cost-effective Sn-doped In2O3 films are deposited onto borosilicate glass substrates using a direct current sputtering of metallic In/Sn-target. The film thickness was controlled by the deposition time. A post-deposition annealing of the films in a vacuum atmosphere was performed in order to control the structural, optical and electrical properties. The phase formation, crystallite grain sizes (D) and lattice parameters have been assessed from the X-ray diffraction data analysis. Cross-section Scanning electron microscope image analyses were performed in order to estimate the growth rate of thin films. A band gap energy closing was observed associated with relaxation process of the unit cell suggested by the monotonic reduction of the lattice constant. Besides, a low sheet resistance (44 Ohm/square) was obtained, which is comparable to the commercially available ITO films. Furthermore, a inverse-square dependence between the sheet resistance and the grain size was determined (R-sq similar to 1/D-2). The last was used to estimate the carrier concentration of the thicker film similar to 10(20) cm(-3), which is in agreement with the value obtained from the Hall measurement.Universidad Nacional de San Agustin de ArequipaConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAP/DFUniv Nacl San Agustin Arequipa, Lab Peliculas Delgadas, Escuela Profes Fis, Av Independencia S-N, Arequipa, PeruUniv Brasilia, Inst Fis, Nucleo Fis Aplicada, BR-70910900 Brasilia, DF, BrazilUniv Estadual Paulista, Dept Fis, IGCE, BR-13506900 Rio Claro, SP, BrazilUniv Fed Sao Carlos, Ctr Ciencias Exatas & Tecnol, Dept Fis, BR-13565905 Sao Carlos, SP, BrazilUniv Estadual Paulista, Dept Fis, IGCE, BR-13506900 Rio Claro, SP, BrazilUniversidad Nacional de San Agustin de Arequipa: IBAIB-04-2018-UNS
Cu nanoclusters in ion exchanged soda-lime glass : study of SPR and nonlinear optical behavior for photonics
Please read abstract in the article.The South African Research Chairs Initiative of the Department of Science and Technology (84415) and the National Research Foundation (Prof. R.E. Kroon, Grant Number 93214) for photoluminescence measurements.http://www.elsevier.com/locate/apmt2020-06-01hj2019Physic
