An extended Falicov-Kimball model on a triangular lattice

The combined effect of frustration and correlation in electrons is a matter of considerable interest of late. In this context a Falicov-Kimball model on a triangular lattice with two localized states, relevant for certain correlated systems, is considered. Making use of the local symmetries of the model, our numerical study reveals a number of orbital ordered ground states, tuned by the small changes in parameters while quantum fluctuations between the localized and extended states produce homogeneous mixed valence. The inversion symmetry of the Hamiltonian is broken by most of these ordered states leading to orbitally driven ferroelectricity. We demonstrate that there is no spontaneous symmetry breaking when the ground state is inhomogeneous. The study could be relevant for frustrated systems like $GdI_2$, $NaTiO_2$ (in its low temperature C2/m phase) where two Mott localized states couple to a conduction band.Comment: 6 pages, 8 figure

Study of ground state phases for spin-1/2 Falicov-Kimball model on a triangular lattice

The spin-dependent Falicov-Kimball model (FKM) is studied on a triangular lattice using numerical diagonalization technique and Monte-Carlo simulation algorithm. Magnetic properties have been explored for different values of parameters: on-site Coulomb correlation $U$, exchange interaction $J$ and filling of electrons. We have found that the ground state configurations exhibit long range Ne\`el order, ferromagnetism or a mixture of both as $J$ is varied. The magnetic moments of itinerant ($d$) and localized ($f$) electrons are also studied. For the one-fourth filling case we found no magnetic moment from $d$- and $f$-electrons for $U$ less than a critical value.Comment: 6 pages, 8 figure

IN VITRO ANTIOXIDANT POTENTIAL, FREE RADICAL SCAVENGING AND CYTOTOXIC ACTIVITY OF SIMAROUBA GLUACA LEAVES.

Objective: To investigate the total phenolic, flavonoids, tannin contents of Simarouba glauca leaves and evaluate the antioxidant potential and cytotoxic activity in different human cell lines.Methods: The methanol, ethanol and water extracts of S. glauca leaves were examined for total phenolics, flavonoid and tannin content. Its antioxidant properties using FRAP, Phosphomolybdenum, Ferric ferrozine assays and free radical scavenging using DPPH were determined. Further, the reducing power and iron chelating effect of the extract using spectrophotometric assays were estimated. Finally, the cytotoxic activity against few human cancer cell lines were also examined using MTT assay.Results: The phytochemical investigations revealed that S. glauca leaves has only 0.14 to 0.18% of flavonoids, 250-400µg/mg phenolics and 67-200µg/mg tannin content in various solvent extracts. The extracts exhibited good reducing power with similar EC50 values aproximately in the range of 57-61µg /ml. Further, the leaf extracts showed iron chelation effect which was more pronounced in aqueous extract with IC50 value of 332µg/ml and exhibited very strong DPPH radical scavenging activity with IC50 vlaues ranging from 9-13µg/ml in various extracts. The methanolic extracts showed good antioxidant potential using FRAP and phopshomolybdenum methods, whereas the aqueous extract exihibited more pronounced antioxidant activty using sensitive ferric ferrozine assay with 580µg AAE/mg extract. The methanolic extract showed strong cytotoxic effect on SCC9 cancer cell line and less potent on HCT116 cancer cells.Conclusion: The findings suggests that Simarouba glauca leaf extract contain bioactive molecules which exhibit antioxidant activity that could be synergisticaly influencing the cytotoxic activity in selected cancer cell lines.Â

Transient ischaemic attack in a patient with known temporal arteritis: a case report

Older populations are more at risk of problems such as temporal arteritis or polymyalgia rheumatica, and these conditions are often first diagnosed in general practice, with usual ongoing care and long-term treatment with oral steroids. These inflammatory conditions are also potential risk factors for other complicating presentations such as transient ischaemic attacks, but the precise comorbid links and how these might influence clinical management in general practice are unclear

Bridge Scour and its Monitoring Using GSM Enabled Sensors – a Laboratory Study

River, Estuarine and Coastal Dynamic

EVALUATION OF ANTIOXIDANT POTENTIAL AND REDUCING POWER OF CALLUS INDUCED FROM LEAVES OF ASYSTASIA GANGETICA (L.) T.ANDERSON

Objective: To evaluate the bioactive molecules and antioxidant potential of callus induced from leaves of Asystasia gangetica. Methods: In this report, the leaves of A.gangetica (AG) were incubated with Murashige and Skoog (MS) medium supplemented with combinations of auxins and cytokinins for callus induction. The qualitative estimation of bioactive molecules like flavonoids, phenolics, tannins and their antioxidant potential were investigated. The ability of radical scavenging activity and reducing power of methanolic, ethanolic and aqueous extract using DPPH, FRAP and Phopshomlybdate assay were carried out. Results: Callus was induced on MS medium supplemented with various concentration and combination of auxins and cytokinins.Maximum percentage of callusing was seen on media supplemented with 2,4-Dichlorophenoxyaceticacid 5mg/L or combination of Kinetin 2mg/L and 2mg/L Napthaleneaceticacid.The total phenolic content, flavonoids and tannins in callus were estimated in various solvents. Further, the callus showed the FRAP values of 17.67 ± 0.0, 17.30 ± 1.830 and 23.81 ± 0.945 µg AAE / mg extract for methanolic, ethanolic and aqueous extract respectively. Methanolic extract showed highest DPPH scavenging activity and reducing abilty. Conclusion: A.gangetica callus had substantial amount of bioactive molecules exhibiting potent antioxidant activity and reducing ability. Development of appropriate strategies for enhancing the bioactive molecules in callus could have far-reaching implications for isolation of novel antioxidant molecules for human health

EVALUATION OF ANTIOXIDANT POTENTIAL AND REDUCING POWER OF CALLUS INDUCED FROM LEAVES OF ASYSTASIA GANGETICA (L.) T.ANDERSON

Objective: To evaluate the bioactive molecules and antioxidant potential of callus induced from leaves of Asystasia gangetica. Methods: In this report, the leaves of A.gangetica (AG) were incubated with Murashige and Skoog (MS) medium supplemented with combinations of auxins and cytokinins for callus induction. The qualitative estimation of bioactive molecules like flavonoids, phenolics, tannins and their antioxidant potential were investigated. The ability of radical scavenging activity and reducing power of methanolic, ethanolic and aqueous extract using DPPH, FRAP and Phopshomlybdate assay were carried out. Results: Callus was induced on MS medium supplemented with various concentration and combination of auxins and cytokinins.Maximum percentage of callusing was seen on media supplemented with 2,4-Dichlorophenoxyaceticacid 5mg/L or combination of Kinetin 2mg/L and 2mg/L Napthaleneaceticacid.The total phenolic content, flavonoids and tannins in callus were estimated in various solvents. Further, the callus showed the FRAP values of 17.67 ± 0.0, 17.30 ± 1.830 and 23.81 ± 0.945 µg AAE / mg extract for methanolic, ethanolic and aqueous extract respectively. Methanolic extract showed highest DPPH scavenging activity and reducing abilty. Conclusion: A.gangetica callus had substantial amount of bioactive molecules exhibiting potent antioxidant activity and reducing ability. Development of appropriate strategies for enhancing the bioactive molecules in callus could have far-reaching implications for isolation of novel antioxidant molecules for human health