infrared studies
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2021 ◽  
Vol 37 (6) ◽  
pp. 1376-1386
Author(s):  
V.C. Ezhilrani ◽  
Vigneshwari. R ◽  
Sasmita Dash

The interaction studies of drug ciprofloxacin with two mixed micellar systems are reported. The mixed micelles comprise a nonionic hydrophobic surfactant, pluronic L-81, an anionic surfactant, Ammonium dodecyl sulfate (ADS); and a cationic surfactant, Cetylpyridinium bromide (CPB). The various combinations chosen were L-81-ADS and L-81-CPB. The properties of both the mixed micelles were compared. Spectrophotometric, conductometric, co-solvent effect, and Infrared studies were used for the investigations. The studies were carried out in a wide range of mixed micellar concentrations in the post micellar region of the individual surfactants. The solubilization of drug CPX in the L-81-ADS was higher than that in L-81-CPB mixed micelle, as evidenced by UV studies. Ethanol and ethylene glycol were found to be effective co-solvents for both the mixed micellar systems. The conductivity studies of CPX with ADS and CPB surfactants, displayed a higher value of conductance for CPX and ADS, from 0.37µs-1 to 0.74µs-1 compared to CPX and CPB. The drug-mixed micelle displayed a higher molecular weight complex formation as seen from the IR spectra.


2021 ◽  
Vol 922 (1) ◽  
pp. L10
Author(s):  
C. E. Woodward ◽  
D. P. K. Banerjee ◽  
T. R. Geballe ◽  
K. L. Page ◽  
S. Starrfield ◽  
...  

Abstract We present near-infrared spectroscopy of Nova Herculis 2021 (V1674 Her), obtained over the first 70 days of its evolution. This fastest nova on record displays a rich emission line spectrum, including strong coronal line emission with complex structures. The hydrogen line fluxes, combined with a distance of 4.7 − 1.0 + 1.3 kpc, give an upper limit to the hydrogen ejected mass of M ej = 1.4 − 1.2 + 0.8 × 10 − 3 M ⊙. The coronal lines appeared at day 11.5, the earliest onset yet observed for any classical nova, before there was an obvious source of ionizing radiation. We argue that the gas cannot be photoionized, at least in the earliest phase, and must be shocked. Its temperature is estimated to be 105.57±0.05 K on day 11.5. Tentative analysis indicates a solar abundance of aluminum and an underabundance of calcium, relative to silicon, with respect to solar values in the ejecta. Further, we show that the vexing problem of whether collisional ionization or photoionization is responsible for coronal emission in classical novae can be resolved by correlating the temporal sequence in which the X-ray supersoft phase and the near-infrared coronal line emission appear.


2021 ◽  
Vol 125 (12) ◽  
pp. 6758-6766
Author(s):  
Alexander I. Lebedev ◽  
Bedil M. Saidzhonov ◽  
Konstantin A. Drozdov ◽  
Andrey A. Khomich ◽  
Roman B. Vasiliev
Keyword(s):  

Author(s):  
A. O. Rajee ◽  
H. F. Babamale ◽  
A. A. Aliyu ◽  
A Lawal ◽  
S. O. Ayinla ◽  
...  

The interaction of selected biometals with dinitrogen donor ligand, 1,10-phennathroline (phen) and amino acid, 2-amino-4-(methylthio)butanoic acid (methionine; met) resulted in isolation of three mononuclear complexes. The prepared complexes were characterized by diverse techniques including elemental and spectroscopic analysis. From the analytical and spectral data, octahedral geometry was proposed to the synthesized metal (II) complexes. Bonding of the metal ion through N- and O- donor atoms of the ligands is revealed by infrared studies. The compounds showed moderate solubility in distilled water and in some common organic solvents. In vivo evaluation of the antimicrobial activities of the metal complexes showed improved inhibitory activity against some micro-organisms as compared to the ligands, with Co(II) and Cu(II) complexes showing the highest activities against the fungi.


Author(s):  
JUNMONI NATH

Objectives: To meet the above aim the following objectives are undertaken: (1) Isolation of starch from jackfruit seeds and formulation of curcumin loaded jackfruit seed starch nanoparticles (2) In vitro evaluations of the drug loaded nanoparticles Methods: Jackfruit seed starch nanoparticles were prepared by Nanoprecipitation technique. In this technique, jackfruit seed starch was mixed with curcumin and acetone solution using a magnetic stirrer at 600 rpm. To the above solution, water were added dropwise and stirred at room temperature until acetone was completely vaporized. Nanoparticles were separated by centrifugation at 4000 rpm after 40 min. Results: Particle size of prepared nanoparticle formulations was found to be 371 to 411.72 nm with PDI of 0.148 to 0.356. The maximum % drug entrapment was found to be 57.34 % with formulation F5. In vitro release studies showed sustained release of drug till 12 h. Conclusion: The prepared nanoparticles were evaluated for its particle size, drug entrapment efficiency, in vitro drug release study, and surface morphology studies by scanning electron microscopy. The results of Fourier transform infrared studies of 1:1 physical mixture of drug and excipients confirmed the absence of incompatibility. Thus, the study concludes that curcumin loaded jackfruit seed starch nanoparticles were developed successfully by nanoprecipitation, which is expected to enhance the oral bioavailability of curcumin.


2020 ◽  
Vol 126 (12) ◽  
Author(s):  
B. Lalitha Devi ◽  
K. Mohan Rao ◽  
D. Ramananda

AbstractIn this article, the capping action of Sodium carboxymethyl cellulose (NaCMC) on ZnS nanoparticles synthesized by microwave-assisted method is reported. The X-ray diffraction and electron diffraction studies corroborated nanocrystalline nature of cubic ZnS. Discontinuous cluster growth of particles was implied by optical absorption studies. This was reflected in transmission electron microscope images. Fourier-transform infrared studies confirmed NaCMC capping on the surface of ZnS nanoparticles. Effective encapsulation of ZnS nanoparticles by NaCMC was further supported by Raman scattering, thermal studies and photoluminescence studies. Surface modification of ZnS nanoparticles with NaCMC appear to be suitable for specific biomedical applications due to the nontoxicity of ZnS and NaCMC.


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