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Sumathi Rajamani Tamizharasi Sengodan Sivakumar Thangavelu 《Drug development and industrial pharmacy》2018,44(11):1752-1761
Naringenin (NAR) is a naturally occurring plant flavonoid, found predominantly in citrus fruits, possesses a wide range of pharmacological properties. However, despite the therapeutic potential of NAR, its clinical development has been hindered due to low aqueous solubility and inefficient transport across biological membranes resulting in low bioavailability at tumor sites. In our previous studies, nanosuspension of naringenin (NARNS) was prepared using high pressure homogenization method using different polymers. D-α-Tocopheryl polyethylene glycol succinate 1000 (TPGS) was added as a co-stabilizer. All formulation characterization studies were performed. As a continuation of our previous research, current study has further evaluated the ability of the TPGS-coated NARNS, to reverse drug-resistance of P-gp-over expressing MCF-7 human breast adenocarcinoma cell line and animal model. MTT-based colorimetric assay revealed higher cytotoxic efficacy of NARNS than free NAR in MCF-7 cells. NARNS treatment significantly increased intracellular ROS level, mitochondrial membrane potential, caspase-3 activity, lipid peroxidation status (TBARS) and decreased GSH levels when compared to free NAR treatment in MCF-7 cells. It has been also noticed that the presence of apoptotic indices (membrane blebbing, nuclear fragmentation) in NARNS treated cancer cells. Further, NARNS exhibited dose-dependent in vitro antitumor activity with DLA cells. A significant increase in the life span and a decrease in the cancer cell number and tumor weight were noted in the tumor-induced mice after treatment with NARNS. 相似文献
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Sengodan Senthil 《Polymer》2004,45(11):3609-3614
Main chain liquid crystalline polyphosphonates containing semi-flexible phenylester mesogen with even number of methylene spacers (2-10) have been synthesized. The monomers and polymers were characterized by IR, 1H, 13C and 31P NMR spectroscopy. The spectral details are in accordance with the structures. All the polymers were exhibited liquid crystalline property in the Hot stage optical polarized microscope (HOPM). DSC thermal analysis confirms the mesophase formation for all the polymers. The grain size of the liquid crystalline mesophase is increasing with increasing methylene chain. Tg, Tm and Ti of the polymers decreased with increase in spacer length. The Tg of these phosphorus-containing polymers is much lower than that of non-phosphorus polymers containing triad ester mesogens. Energy minimized structures for the molecules which mimic the polymer chain suggests that the reduction in Tg may be due to entanglement raised by incorporation of phosphorus heterogeneity. 相似文献
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CdSxTe1−x films were deposited on titanium and conducting glass substrates at room temperature using 0.25 M cadmium sulphate, the concentration of sodium thiosulphate and TeO2 dissolved in sodium hydroxide was varied in the range of 0.01-0.05 M. The as deposited films exhibited hexagonal structure irrespective of the composition. The FWHM maximum of the x-ray diffraction peaks were found to decrease with increase of duty cycle. The optical energy gap values are in the range of 1.54-2.32 eV for films of different composition, it is observed that the band gap shifts towards CdS side as the concentration of CdS in the films increase. XPS studies indicated the formation of CdSTe solid solution. The grain size increases from 11.54 to 99.40 nm as the value of x increases from 0.2 to 0.8. The surface roughness is found to increase from 0.22 to 2.50 nm as the value of ‘x’ increases from 0.2 to 0.8. The resistivity is found to vary from 53 to 8 ohm cm as the ‘x’ value decreases from 1 to 0. 相似文献
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This paper presents a modification in pulse width modulation (PWM) scheme with unequal shoot-through distribution for the Z-source inverter (ZSI) which can minimize ripples in the current through the Z-source inductors as well as the voltage across the Z-source capacitors. For the same system parameters, the proposed control technique provides better voltage boost across the Z-source capacitor, DC-link, and also the AC output voltage than the traditional PWM. The ripples in the Z-network elements are found to be reduced by 75 % in the proposed modulation scheme with optimum harmonic profile in the AC output. Since the Z-network requirement will be based on the ripple profile of the elements, the Z-network requirements can be greatly reduced. The effectiveness of the proposed modulation scheme has been simulated in Matlab/Simulink software and the results are validated by the experiment in the laboratory. 相似文献
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K. R. Murali P. Thirumoorthy V. Sengodan 《Journal of Materials Science: Materials in Electronics》2009,20(3):206-211
Cadmium sulphide (CdS) films were deposited by the pulse plating technique at room temperature and at different duty cycles
in the range of 6–50% using AR grade 0.25 M cadmium sulphate and 0.30 M sodium thiosulphate at a deposition potential of −0.75 V
(SCE). The total deposition time was kept constant at 1 h. The thickness of the films were around 2.0 μm. X-ray diffraction
(XRD) studies indicate the formation of polycrystalline films with the cubic structure. The crystallite size increased from
23.0 to 27.5 nm as the duty cycle increased from 10 to 50%. Optical absorption studies indicated a direct band gap in the
range of 2.40–2.80 eV as the duty cycle is decreased. XPS studies indicated the formation of CdS. Photoelectrochemical (PEC)
cell measurements made with the photoelectrodes deposited at 50% duty cycle have exhibited higher conversion efficiency compared
to earlier reports. 相似文献
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Ravichandran Siranjeevi Radhakrishnan Jeyalakshmi Sengodan Prabhu Rajendran Ramesh 《Journal of Materials Science: Materials in Electronics》2022,33(12):9403-9411
Journal of Materials Science: Materials in Electronics - The production of energy-storage devices is primarily concerned with cost-effective solutions that increase efficiency and stability. Due to... 相似文献
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