Academy of Scientific and Innovative Research AcSIR New Delhi

India

Academy of Scientific and Innovative Research AcSIR New Delhi

India
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Shome S.,Indian Institute of Chemical Technology | Shome S.,Academy of Scientific and Innovative Research AcSIR New Delhi | Singh S.P.,Indian Institute of Chemical Technology | Singh S.P.,Academy of Scientific and Innovative Research AcSIR New Delhi
Tetrahedron Letters | Year: 2017

Two new ruthenium bipyridine complexes were designed and synthesized for intermolecular Csp2-H hydroxylation. An environmentally begin and inexpensive oxidant was employed as an oxygen source thereby enhancing its applicability and resulting in the remarkable increase of yield. In the catalytic process a ruthenium (IV) cationic complex is formed which enables the regioselective C–O bonds formation and also proves to be tolerant to a broad substrate scope. Activation of C–H bonds adjacent to removable and non-removable directing groups have been explored efficiently. © 2017 Elsevier Ltd


Pain A.,Academy of Scientific and Innovative Research AcSIR | Pain A.,Geotechnical Engineering Group | Choudhury D.,Indian Institute of Technology Bombay | Choudhury D.,Academy of Scientific and Innovative Research AcSIR New Delhi | Bhattacharyya S.K.,Academy of Scientific and Innovative Research AcSIR New Delhi
Soil Dynamics and Earthquake Engineering | Year: 2017

Seismic stability analysis is an important aspect for design of safe retaining walls in earthquake prone areas. In this study, limit equilibrium method is used for rotational stability analysis of gravity retaining wall on rigid foundation supporting dry cohesionless backfill with modified pseudo-dynamic seismic forces. Proposed method satisfies the zero stress boundary condition at free ground surface and considers the amplification of acceleration. Stability factor FW is proposed to determine the safe weight of the retaining wall against rotational failure under seismic conditions. If the safe weight of the retaining wall is known under static condition then by simply multiplying that with FW can give the safe weight of the retaining wall against rotational failure under seismic condition. Present study shows that wall-soil interaction in various seismic conditions may or may not be in-phase for the entire duration of the input motion. It depends on the properties of the backfill soil, properties of the wall material and also on the frequency content of the input motion. A modified rotating block method is proposed to obtain the rotational displacement under seismic conditions. Present results give higher values of rotational displacements of the wall when compared with the available results by pseudo-static analysis. Hence the present study may be used to design seismically stable retaining wall. © 2017 Elsevier Ltd


Arun K.B.,Indian National Institute for Interdisciplinary Science and Technology | Thomas S.,Indian National Institute for Interdisciplinary Science and Technology | Thomas S.,Academy of Scientific and Innovative Research AcSIR New Delhi | Reshmitha T.R.,Indian National Institute for Interdisciplinary Science and Technology | And 2 more authors.
Journal of Functional Foods | Year: 2017

The present study investigated nutraceutical properties of Musa paradisiaca (Nendran variety) inflorescence (PI). PI was found to be a rich source of soluble (SDF) and insoluble dietary fibre (12.45 and 53.31% respectively). SDF exhibited potential glucose and cholesterol adsorption capacity. Ethyl acetate (PIE) and methanol (PIM) extracts of PI were analyzed for phenolics content, antioxidant activities, antidiabetic and cardiovascular protection efficacy. PIM exhibited significant ABTS free radical scavenging activity (IC50-57.2 ± 1.15 μg/mL) and inhibited the production of reactive oxygen species in L6 myoblasts in a dose-dependent manner. PIM also demonstrated potential inhibition of carbohydrate digestive enzymes (α-amylase and α-glucosidase), interfered with the production of glycated end products (IC50-142.27 ± 1.09 μg/mL) and enhanced glucose uptake in L6 myoblasts. PIM inhibited LDL oxidation (IC50-169.52 ± 1.77 μg/mL) and ACE, indicating its protective role against cardiovascular risk factors. The study demonstrated the nutraceutical potential of PI in ameliorating type 2 diabetes and associated cardiovascular problems. © 2017 Elsevier Ltd


Bejoymohandas K.S.,Indian National Institute for Interdisciplinary Science and Technology | Bejoymohandas K.S.,Academy of Scientific and Innovative Research AcSIR New Delhi | Kumar A.,University of Burgundy | Varughese S.,Indian National Institute for Interdisciplinary Science and Technology | And 4 more authors.
Journal of Materials Chemistry C | Year: 2015

Herein, we have synthesized a series of 2′,6′-difluoro-2,3′-bipyridine cyclometalating ligands by substituting electron-withdrawing (-CHO, -CF3, and -CN) and electron-donating (-OMe and -NMe2) groups at the 4′ position of the pyridyl moiety and utilized them for the construction of five new iridium(iii) complexes (Ir1-Ir5) in the presence of picolinate as an ancillary ligand. The photophysical properties of the developed iridium(iii) compounds were investigated with a view to understand the substituent effects. The strong electron-withdrawing (-CN) group containing the iridium(iii) compound (Ir3) exhibits highly efficient genuine green phosphorescence (λmax = 508 nm) at room temperature in solution and in thin film, with an excellent quantum efficiency (ΦPL) of 0.90 and 0.98, respectively. On the other hand, the -CF3 group substituted iridium(iii) compound (Ir2) displays a sky-blue emission (λmax = 468 nm) with a promising quantum efficiency (ΦPL = 0.88 and 0.84 in solution and in thin film, respectively). The -CHO substituted iridium(iii) complex (Ir1) showed greenish-yellow emission (λmax = 542 nm). Most importantly, the strong electron-donating -NMe2 substituted iridium(iii) complex (Ir5) gives a structureless and a broad emission profile in the wavelength region 450 to 700 nm (λmax = 520 nm) with a poor quantum efficiency. An intense blue phosphorescence with impressive quantum efficiency, especially in thin-film noted in the case of the -OMe substituted iridium(iii) complex (Ir4). Comprehensive density functional theory (DFT) and time-dependent DFT (TD-DFT) approaches have been performed on the ground and excited states of the synthesized iridium(iii) complexes, in order to obtain information about the absorption and emission processes and to gain deeper insights into the photophysical properties. The combinations of a smaller ΔES1-T1 and higher contribution of 3MLCT in the emission process result in the higher quantum yields and lifetime values for complexes Ir1-Ir3. Multi-layered Phosphorescent Organic Light Emitting Diodes (PhOLEDs) were designed using the phosphorescent dopants Ir2, Ir3 and Ir4 and their elecroluminescence properties were evaluated. Compound Ir4 at a doping level of 5 wt% shows the best performance with an external quantum efficiency of 4.7%, in the nonoptimized device, and a power efficiency of 5.8 lm W-1, together with a true-blue chromacity CIEx,y = 0.15, 0.17 recorded at the maximum brightness of 33 180 cd m-2. This journal is © The Royal Society of Chemistry.


Divyashri G.,Academy of Scientific and Innovative Research AcSIR New Delhi | Divyashri G.,Indian Central Food Technological Research Institute | Krishna G.,Indian Central Food Technological Research Institute | Muralidhara,Indian Central Food Technological Research Institute | Prapulla S.G.,Indian Central Food Technological Research Institute
Journal of Medical Microbiology | Year: 2015

Accumulating evidence suggests that probiotic bacteria play a vital role in modulating various aspects integral to the health and well-being of humans. In the present study, probiotic attributes and the antioxidant, anti-inflammatory and neuromodulatory potential of Enterococcus faecium CFR 3003 were investigated by employing suitable model systems. E. faecium exhibited robust resistance to gastrointestinal stress conditions as it could withstand acid stress at pH 1.5, 2 and 3. The bacterium also survived at a bile salt concentration of 0.45 %, and better tolerance was observed towards pepsin and trypsin. E. faecium produced lactic acid as a major metabolic product, followed by butyric acid. Lyophilized cell-free supernatant (LCS) of E. faecium exhibited significant antioxidant capacity evaluated against 1,1-diphenyl-2-picryl-hydrazyl, ascorbate autooxidation, oxygen radical absorbance and reducing power. Interestingly, E. faecium, Lactobacillus rhamnosus GG MTCC 1408 and LCS showed a significant anti-inflammatory effect by negatively modulating TNF-α production and upregulating IL-10 levels in LPS-stimulated macrophage cell lines. In an in vivo mice model, the propensity of probiotic supplements to modulate endogenous oxidative markers and redox status in brain regions was assessed. Young mice provided with oral supplements (daily for 28 days) of E. faecium and L. rhamnosus exhibited diminished oxidative markers in the brain and enhanced activities of antioxidant enzymes with a concomitant increase in γ-aminobutyric acid and dopamine levels. Collectively, our findings clearly suggest the propensity of these bacteria to protect against tissue damage mediated through free radicals and inflammatory cytokines. Although the underlying molecular mechanisms need further studies, it is tempting to speculate that probiotics confer a neuroprotective advantage in vivo against oxidative damage-mediated neurodegenerative conditions. © 2015 The Authors.


Maruthapandian V.,CSIR - Central Electrochemical Research Institute | Maruthapandian V.,Academy of Scientific and Innovative Research AcSIR New Delhi | Saraswathy V.,CSIR - Central Electrochemical Research Institute | Saraswathy V.,Academy of Scientific and Innovative Research AcSIR New Delhi | Muralidharan S.,CSIR - Central Electrochemical Research Institute
Cement and Concrete Composites | Year: 2016

Corrosion of steel reinforcement concrete structures is monitored through the surface mounting techniques using liquid based reference electrodes. Due to the limited usage of liquid based reference electrodes solid state reference electrode are introduced recently. In the present study, we fabricated and characterized Mn3O4 based pellet electrode for corrosion assessment of steel rebar in high alkaline medium through electrochemical methods and the results are compared with conventional saturated calomel reference electrode (SCE). The results indicate that the fabricated pellet electrode exhibits better characteristics suitable for high alkaline concrete environment and differentiate the passive and active status of steel rebar. © 2016 Elsevier Ltd


Gaur R.,Central Institute of Medicinal and Aromatic Plants | Gaur R.,Academy of Scientific and Innovative Research AcSIR New Delhi | Pathania A.S.,Indian Institute of Integrative Medicine | Pathania A.S.,Academy of Scientific and Innovative Research AcSIR New Delhi | And 5 more authors.
European Journal of Medicinal Chemistry | Year: 2016

A new series of monomer and dimer derivatives of dihydroartemisinin (DHA) containing substituted chalcones as a linker were synthesized and investigated for their cytotoxicity in human cancer cell lines HL-60 (leukemia), Mia PaCa-2 (pancreatic cancer), PC-3 (prostate cancer), LS180 (colon cancer) and HEPG2 (hepatocellular carcinoma). Some of these derivatives have greater antiproliferative and cytotoxic effects in tested cell lines than parent compound DHA. The structures of the all compounds were confirmed by IR, 1H NMR and mass spectral data. Among the new derivatives, compounds 8, 14, 15, 20 and 24 were found to be more active than parent DHA against tested human cancer cell lines. DHA derivatives were found to be most active in human leukemia cell lines with compounds 8, 14, 15, 20 and 24 showed IC50 values less than 1 μM for 48 h whereas DHA has IC50 value of 2 μM at same time period. The most potent compounds 8 with IC50 = 0.3 μM (at par with doxorubicin (IC50 = 0.3 μM)) and 15 with IC50 = 0.4 μM, of the series, six and three times active than DHA (with IC50 = 2 μM) respectively were selected for further mechanistic work in human leukemia HL-60 cells. © 2016 Elsevier Masson SAS


Joseph A.M.,Indian National Institute for Interdisciplinary Science and Technology | Joseph A.M.,Academy of Scientific and Innovative Research AcSIR New Delhi | Nagendra B.,Indian National Institute for Interdisciplinary Science and Technology | Nagendra B.,Academy of Scientific and Innovative Research AcSIR New Delhi | And 4 more authors.
ACS Applied Materials and Interfaces | Year: 2015

Homogeneously dispersed hybrid silica/syndiotactic polystyrene composites were investigated for low-κ dielectric applications. The composites were prepared by a solution blending method, and their microstructures were analyzed by SEM, TEM, and AFM. Crystallization and phase transformation behavior of sPS were investigated using differential scanning calorimetry and wide-angle X-ray diffraction. These composites exhibited improved thermal stability and reduced thermal expansion coefficients. Promising dielectric properties were observed for the composites in the microwave frequency region with a dielectric constant (κ = 1.95) and loss (tan δ = 10-4) at 5 GHz. © 2015 American Chemical Society.


Naeem K.C.,Indian National Institute for Interdisciplinary Science and Technology | Naeem K.C.,Academy of Scientific and Innovative Research AcSIR New Delhi | Subhakumari A.,Indian National Institute for Interdisciplinary Science and Technology | Varughese S.,Indian National Institute for Interdisciplinary Science and Technology | And 2 more authors.
Journal of Materials Chemistry C | Year: 2015

Two donor-π-acceptor type fluorophores consisting of anthracene as the donor and benzoxazole (ABO) or benzothiazole (ABT) as the acceptor are synthesised. Both fluorophores exhibit excellent solid state luminescence, and respond to external stimuli such as mechanical force (mechanochromism) and protons (acidochromism). Though the differences between the two molecules are marginal, their stimuli responsive behaviours are contrasting. ABO shows stable mechanochromism but the protonation induced colour change is unstable. On the other hand, ABT shows stable acidochromism but luminescence changes induced by mechanical stress are reverted back quickly. A detailed study reveals that the variance in the heteroatoms in benzoxazole/benzothiazole moieties (oxygen and sulphur, respectively) significantly affects both the intra- and intermolecular electronic interactions of the molecules resulting in such observations. In the case of ABO, the benzoxazole moieties interact through weak edge-to-edge π-stacking, whereas in ABT, the ring overlap is more significant making the π-stacking a stronger face-to-face type, which helps in the restoration of the molecular ordering in ABT, which is energetically more viable. Regarding the acidochromic properties, the presence of more electronegative oxygen (compared to sulphur) in ABO draws electrons efficiently towards it making the nitrogen less basic and the complex formed between ABO and TFA less stable. On the other hand, electron density on the nitrogen in ABT might be higher compared to ABO due to the presence of less electronegative sulphur leading to the formation of a stable complex between ABT and TFA. © The Royal Society of Chemistry.


Kandhadi J.,Indian Institute of Chemical Technology | Yeduru V.,Indian Institute of Chemical Technology | Yeduru V.,Academy of Scientific and Innovative Research AcSIR New Delhi | Bangal P.R.,Indian Institute of Chemical Technology | And 3 more authors.
Physical Chemistry Chemical Physics | Year: 2015

Two different donor-acceptor systems based on corrole-ferrocene and corrole-anthraquinone having the 'Olefin Bridge' at the β-pyrrole position have been designed and synthesized. Both the dyads corrole-ferrocene (Cor-Fc) and corrole-anthraquinone (Cor-AQ) are characterized by elemental analysis, ESI-MS, 1H NMR, UV-Visible, fluorescence spectroscopies (steady-state, femtosecond time-resolved), femtosecond transient absorption spectroscopy (fs-TA) and electrochemical methods. 1H-NMR shows that two doublets at 6.50 and 7.25(δ) ppm belong to vinylic protons, which are characteristic of the formation of dyads. UV-Visible absorption spectra showed that dyads are merely superpositions of their respective constituent monomers and dominated by corrole S1 ← S0 (Q-band) and S2 ← S0 (Soret band) transitions with a systematic red-shift of both Soret and Q-bands along with the broadening of the bands. A prominent splitting of the Soret band for both the dyads is observed due to bulky substitutions at the peripheral position, which deviate from the planarity of the corrole macrocycle. Both the dyads exhibit significant fluorescence emission quenching (95-97%) of corrole emission compared to the free-base corrole monomer. Emission quenching is attributed to the excited-state intramolecular photoinduced electron transfer (PET) from corrole to anthraquinone in the Cor-AQ dyad, whereas in the Cor-Fc dyad it is reversed. The electron-transfer rates (kET) for Cor-AQ and Cor-Fc were found to be 3.33 × 1011 and 2.78 × 1010 s-1, respectively. Despite their very different driving forces, charge separation (CS) and charge recombination (CR) are found to be in identical timescales. This journal is © the Owner Societies.

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