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1.
S. Sathyamoorthi V. Suryanarayanan D. Velayutham 《Journal of Solid State Electrochemistry》2014,18(10):2789-2796
Simultaneous electrochemical generation and functionalization of nano-sized graphite from graphite had been carried out in a non-fluoroanion-based ionic liquid, namely, triethylmethylammonium methylsulfate (TEMAMS) containing water and acetonitrile (AN) in different weight ratios. The oxygen-based functional groups attached with the exfoliated material had been identified using Fourier transform infrared spectroscopy (FTIR), and morphological changes were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). A symmetrical supercapacitor was fabricated using the exfoliated nano-sized graphite, and the influence of surface functionalities on its performance was investigated using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and galvanostatic charge–discharge cycles (CC). The highest specific capacitance (C sp) value of 140 F g?1 at 0.25 A g?1 was obtained in 1.0 M H2SO4, followed by aqueous TEMAMS (125 F g?1), TEMAMS/acetonitrile (115 F g?1), and TEMAMS (106 F g?1) at 0.10 A g?1. 相似文献
2.
T.M. Rangarajan D. Velayutham M. Noel R.P. Singh 《Journal of fluorine chemistry》2011,132(2):107-7021
The partially fluorinated HF soluble intermediates formed during the electrochemical perfluorination of propionyl chloride (PC) and n-butyryl chloride (n-BC) were analyzed after passing 0%, 25%, 50%, 75% and 100% of theoretical charge required for the fluorination of PC and n-BC. The acid fluorides formed were converted to their corresponding sodium salt by alkali treatment and were separated by methanol extraction. The methanol was subsequently removed from the extract by vacuum distillation and the residue containing partially fluorinated sodium carboxylates was analyzed using 19F and 1H NMR spectra. Initial perfluorination on activated electrode surface indicates the operation of ‘zipper-mechanism’. Formation of partially fluorinated product mixture, initial selectivity towards primary and secondary carbon, carbon chain isomerization and formation of cleaved and coupled products support the general operation of free radical pathway in the overall electrochemical process. 相似文献
3.
M. Velayutham Pillai K. Rajeswari C. Udhaya Kumar C. Ramalingan A. Manohar 《Phosphorus, sulfur, and silicon and the related elements》2016,191(9):1209-1215
A series of N–thiocyanatoacetyl derivatives of 3–alkyl–2,6–diarylpiperidin–4–ones has been synthesized by the reaction between the N–chloroacetyl derivatives of the respective piperidin–4–ones and the ambident thiocyanate nucleophile. The synthesized compounds have been characterized through FT–IR, 1H, 13C, 1H–1H COSY, 1H–13C COSY and NOESY spectra. The spectral data reveal the conformational priority of the six-membered heterocyclic ring. 相似文献
4.
Sonu Kumar Rajveer Singh Debrupa Dutta Shivani Chandel Arka Bhattacharya Velayutham Ravichandiran Soumi Sukla 《Molecules (Basel, Switzerland)》2022,27(23)
Natural products are being targeted as alternative anticancer agents due to their non-toxic and safe nature. The present study was conducted to explore the in vitro anticancer potential of Justicia adhatoda (J. adhatoda) leaf extract. The methanolic leaf extract was prepared, and the phytochemicals and antioxidant potential were determined by LCMS analysis and DPPH radical scavenging assay, respectively. A docking study performed with five major alkaloidal phytoconstituents showed that they had a good binding affinity towards the active site of NF-κB. Cell viability assay was carried out in five different cell lines, and the extract exhibited the highest cytotoxicity in MCF-7, a breast cancer cell line. Extract-treated cells showed a significant increase in nitric oxide and reactive oxygen species production. Cell cycle analysis showed an arrest in cell growth at the Sub-G0 phase. The extract successfully inhibited cell migration and colony formation and altered mitochondrial membrane potential. The activities of superoxide dismutase and glutathione were also found to decrease in a dose-dependent manner. The percentage of apoptotic cells was found to increase in a dose-dependent manner in MCF-7 cells. The expressions of caspase-3, Bax, and cleaved-PARP were increased in extract-treated cells. An increase in the expression of NF-κB was found in the cytoplasm in extract-treated cells. J. adhatoda leaf extract showed a potential anticancer effect in MCF-7 cells. 相似文献
5.
C. Ramesh G. Velayutham N. Murugesan V. Ganesan V. Manivannan G. Periaswami 《Ionics》2004,10(1-2):50-55
An improved polymer electrolyte membrane (PEM) fuel cell based amperometric hydrogen sensor that operates at room temperature
has been developed. The electrolyte used in the sensor is PVA/H3PO4 blend, which is a proton conducting solid polymer electrolyte. A blend of palladium and platinum coated on the membrane is
used as anode and platinum as cathode. The sensor functions as a fuel cell, H2/Pd-Pt//PVA-H3PO4//Pt/O2, and the short circuit current is found to be linearly related to the hydrogen concentration. The present study aims at investigating
the dependence of sensor behaviour on the anode composition.
Paper presented at the 2nd International Conference on Ionic Devices, Anna University, Chennai, India, Nov. 28–30, 2003. 相似文献
6.
G. Velayutham C. Ramesh N. Murugesan V. Manivannan K. S. Dhathathreyan G. Periaswami 《Ionics》2004,10(1-2):63-67
A Nafion based amperometric hydrogen sensor that operates at room temperature has been developed. The electrolyte used in
the sensor is Nafion 117, which is a proton conducting solid polymer electrolyte. Palladium catalyst was used on the sensing
side and platinum supported on carbon on the air side. The sensor functions as fuel cell, H2/Pd//Nafion//Pt/O2 and the short circuit current is measured. The short circuit current is found to be linear with respect to concentration
of hydrogen on the sensing side. The sensor is able to detect the concentration of hydrogen in argon down to ppb level. Details
of assembly of the sensor, response behavior and applications are discussed.
Paper presented at the 2nd International Conference on Ionic Devices, Anna University, Chennai, India, Nov. 28–30, 2003. 相似文献
7.
8.
Murugesan Velayutham Martin Poncelet Timothy D. Eubank Benoit Driesschaert Valery V. Khramtsov 《Molecules (Basel, Switzerland)》2021,26(9)
Alterations in viscosity of biological fluids and tissues play an important role in health and diseases. It has been demonstrated that the electron paramagnetic resonance (EPR) spectrum of a 13C-labeled trityl spin probe (13C-dFT) is highly sensitive to the local viscosity of its microenvironment. In the present study, we demonstrate that X-band (9.5 GHz) EPR viscometry using 13C-dFT provides a simple tool to accurately measure the microviscosity of human blood in microliter volumes obtained from healthy volunteers. An application of low-field L-band (1.2 GHz) EPR with a penetration depth of 1–2 cm allowed for microviscosity measurements using 13C-dFT in the living tissues from isolated organs and in vivo in anesthetized mice. In summary, this study demonstrates that EPR viscometry using a 13C-dFT probe can be used to noninvasively and rapidly measure the microviscosity of blood and interstitial fluids in living tissues and potentially to evaluate this biophysical marker of microenvironment under various physiological and pathological conditions in preclinical and clinical settings. 相似文献
9.
K. Rajaram M. Moushmi M. Velayutham Dass Prakash Premkumar Kumpati M. Ganasaraswathi P. Sureshkumar 《Applied biochemistry and biotechnology》2013,171(8):2105-2120
Tephrosia tinctoria, a perennial under shrub of Fabaceae family, is endemic to Western Ghats. In this study, friable whitish yellow callus was developed after 45 days using Murashige and Skoog medium supplemented with 2,4-dichlorophenoxyacetic acid (2.0 mg/l)?+?6-benzylaminopurine (0.5 mg/l) in various explants of T. tinctoria. The ethyl acetate extracts of leaf (LE), stem (SE), and root (RE) were compared with leaf (LCE), stem (SCE), and root (RCE) derived callus, for antioxidant and antiproliferative activities. The SE possessed the highest phenolic and flavonoid content among all the extracts tested and showed a significant antioxidant assays. The study of anticancer activity on human hepatocellular carcinoma (HepG2) cell line revealed that the callus extracts especially RCE possessed significant inhibition of cell growth (IC50 20 μg/ml) at 72 h treatment period on analysis with MTT assay. The apoptotic cell death was observed through DNA fragmentation analysis in HepG2 cells treated with the T. tinctoria extracts. The gas chromatography–mass spectrometry finger printing profile showed that more than 60 % percentage of metabolites are similar in both SE and SCE. The higher percentage area of antioxidant compound (stigmast-4-en-3-one) was observed in SE (2.01 %) and higher percentage area of anticancer compound (phenol, 2,4-bis(1,1-dimethylethyl)) in SCE (0.91 %). In addition to that, callus extracts contain squalene, which is used for target deliver and also used as anticancer drug. Thus, the present study revealed that the T. tinctoria has potent antioxidant and antiproliferative activity and the callus culture can be used for the production of the bioactive compounds due to the endemic nature of this plant. 相似文献
10.
Kishore RS Ravikumar V Bernardinelli G Sakai N Matile S 《The Journal of organic chemistry》2008,73(2):738-740
Core-substituted naphthalenediimides (NDIs) are not often used in functional materials despite excellent properties because the harsh conditions used for their synthesis are incompatible with structural diversity. Here, we report rapid access to blue, red, and yellow NDIs under mild conditions with tolerance toward the additional presence of pertinent functional groups. 相似文献