China
Africa
Explore chapters and articles related to this topic
Optical Super-Resolution Imaging Using Surface Plasmon Polaritons
Published in Zhaowei Liu, Plasmonics and Super-Resolution Imaging, 2017
First, let us review imaging results obtained in the hyperlens mode of the 2D plasmonic microscope. The internal structure of the magnifying hyperlens (Fig. 5.4a) consists of concentric rings of PMMA deposited on a gold film surface. The required concentric structures were defined using a Raith e-line electron beam lithography (EBL) system with ∼70 nm spatial resolutions. The written structures were subsequently developed using a 3:1 IPA/MIBK solution (Microchem) as the developer and imaged using atomic force microscopy (AFM) (see Fig. 5.4a). According to theoretical proposals in Refs. [12, 13], optical energy propagates through a hyperbolic metamaterial in the form of radial rays. This behavior is clearly demonstrated in Fig. 5.3b. If point sources are located near the inner rim of the concentric metamaterial structure, the lateral separation of the rays radiated from these sources increases upon propagation toward the outer rim. Therefore, resolution of an immersion microscope based on such a metamaterial structure is defined by the ratio of inner to outer radii. Resolution appears limited only by losses, which can be compensated by optical gain.
Interaction of pseudohalides copper(II) complexes of hydrazide ligand with DNA: synthesis, spectral characterization, molecular docking simulations and superoxide dismutase activity
Published in Inorganic and Nano-Metal Chemistry, 2022
Abhay K. Patel, Neetu Patel, R. N. Jadeja, S. K. Patel, R. N. Patel, S. Kumar, R. Kapavarapu
Infrared (FTIR) spectra were recorded on a Bruker spectrophotometer at normal temperature. KBr pellets were prepared by grinding the sample with KBr (IR grade), in the range of 4000–400 cm−1. NMR spectra of HL were recorded in DMSO-d6 on Bruker Advance 400 MHz (FT-NMR) multinuclear spectrometer. Electronic absorption spectra (300–900 nm) were recorded with a Shimadzu UV-vis recording spectrophotometer UV-1601 in solution. The electrochemistry of the complex (3.0 × 10−3 M) in DMSO containing 0.1 M tetra-butylammonium perchlorate (TBAP) as supporting electrolyte was determined at room temperature by cyclic voltammetry (CV) using a three-electrode system under de-aerated conditions and a BAS 100 electrochemical analyzer. A glassy-carbon electrode and platinum wire were used as the working electrode and the counter electrode, respectively. The reversibility of the electrochemical process was evaluated by standard procedures and all potentials were recorded against an Ag/AgCl reference electrode. All measurements were carried out at 298 K under nitrogen. All solutions were purged with gaseous nitrogen prior to measuring. The low and room temperature electron paramagnetic resonance (EPR) spectra were obtained with a Varian E-line Century Series Spectrometer equipped with a dual cavity and operating at X-band with 100 kHz modulation frequency. Varian quartz tubes were used for obtaining the Epr spectra of the polycrystalline samples and frozen solutions with tetracyanoethylene (TCNE) as a marker (g = 2.00277).
Syntheses, crystal structures, DFT, molecular docking and inhibition studies of jack been urease by nickel (II) and copper (II) Schiff base complexes
Published in Inorganic and Nano-Metal Chemistry, 2018
Sulakshna Bharti, Mukesh Choudhary, Bharti Mohan, S. R. Sharma, K. Ahmad
Starting materials, reagents and solvents were purchased from commercial suppliers with AR grade, and used without purification. Elemental analyses were performed on an ElementarVario EL III Carlo Erba 1108 analyzer. UV-Vis spectra were recorded at 25 °C on a Thermo scientific UV-Vis recording spectrophotometer Evolution-3000 in quartz cells. IR spectra were recorded in KBr medium on a Shimadzu IR Affinity-1Sfourier transform infrared spectrophotometer. X-band Electron Paramagnetic Resonance (EPR) spectra were recorded with a Varian E-line Century Series EPR Spectrometer equipped with a dual cavity and operating at X-band of the 100 kHz modulation frequency at room temperature. Thermal analysis (TGA) was measured from room temperature to 900 °C in N2 on a Perkin Elmer STA 6000 thermal analyzer with a heating rate of 20 °C/min. The urease inhibitory activity was measured on a Bio-Tek Synergy HT microplate reader. Single crystal structures were determined by Bruker D8 Venture single crystal diffraction.
Syntheses, characterizations, crystal structures, antibacterial and SOD-like activities of nickel(II) and copper(II) complexes with 2-((Z)-(4-methoxyphenylimino)methyl)-4,6-dichlorophenol
Published in Journal of Coordination Chemistry, 2018
Sulakshna Bharti, Mukesh Choudhary, Bharti Mohan
Elemental analyses were performed on an ElementarVario EL III Carlo Erba 1108 analyzer. FAB mass spectra were recorded on a JEOL SX 102/DA 6000 mass spectrometer using xenon (6 kV, 10 mA) as the FAB gas. The accelerating voltage was 10 kV and the spectra were recorded at room temperature (RT) with m-nitrobenzyl alcohol as the matrix. Magnetic susceptibility measurements of powder samples of complexes were made on a Gouy balance using mercury(II) tetrathiocyanatocobaltate(II) as calibrating agent (xg = 16.44 × 10−6 c.g.s. units). All the experimental data were corrected for diamagnetic contributions, which were estimated from Pascal’s tables, and temperature-independent paramagnetism (TIP). The molar ion exchange was measured using a systronics digital conductivity meter (TDS-308) using a 10−3 M solution in DMSO. UV–vis spectra were recorded at 25 °C on a Thermo scientific UV–vis recording spectrophotometer Evolution-3000 in quartz cells. Fluorescence spectra were recorded at room temperature on a Horiba Scientific Fluoromax-4 spectrofluorometer in quartz cell. IR spectra were recorded in KBr medium on a Shimadzu IR Affinity-1S Fourier transform infrared spectrophotometer. X-band Electron Paramagnetic Resonance (EPR) spectra was recorded with a Varian E-line Century Series spectrometer equipped with a dual cavity and operating at X-band (~9.4 GHz) with 100 kHz modulation frequency at room temperature. Tetracyanoethylene (TCNE) was used as field marker (g = 2.00277). The frozen solution at liquid nitrogen temperature used for EPR spectra was 3 × 10−3 M in DMSO. Varian quartz tubes were used for measuring EPR spectra of polycrystalline sample and frozen solution. The EPR parameters for copper complex [Cu(L)2] were determined accurately from computer simulation programs such as Monte Carlo, GAMMA, or Easy Spin [28]. Cyclic voltammetry was carried out with a BAS-100 Epsilon electrochemical analyzer having an electrochemical cell with a three-electrode system. Ag/AgCl was used as a reference electrode, glassy carbon as working electrode and platinum wire as an auxiliary electrode. NaClO4 (0.1 M) was used as supporting electrolyte and DMSO as solvent. All measurements were carried out at 298 K under a nitrogen atmosphere. The solution was deoxygenated by purging nitrogen gas. Thermal analysis (TGA) was measured from room temperature to 900 °C in N2 on a Perkin Elmer STA 6000 thermal analyzer with a heating rate of 20 °C/min.