Soil Loss Estimation through USLE and MMF Methods in the Lateritic Tracts of Eastern Plateau Fringe of Rajmahal Traps, India

Laterites of Birbhum district are indentified as the ‘low-level laterites’ of ‘Rarh Plain’ of West Bengal and these are very much prone to severe soil erosion (mainly surface and sub-surface water erosion) in the monsoon season (June - September). Laterites and lateritic soils (locally named ‘Kankara’) of Caniozoic upland (adjoining areas of Rampurhat I block, Birbhum and Shikaripara block, Dumka- the study area), are the direct result of monsoonal wet-dry type of morpho-climatic processes and further laterisation of fluvial deposited materials (formation of surface duricrust) which was coming from Rajmahal Hills of eastern Chotanagpur Plateau (Jharkhand) in late Pleistocene. Such type of vermiform laterites is shaped and dissected by numerous gullies and ravines, giving birth of badland topography (locally named ‘Khoai’) of both degradation and aggradation processes. Before the soil conservation practices it is helpful if the assessment of soil erosion can be transformed into a statement of how fast soil is being eroded. The estimation of rate of annual soil loss is required in that case, because we must have to predict soil loss through effective models under a wide range of conditions. In this study the entire assessment is focused on the application Universal Soil Loss Equation (USLE) and Morgan, Morgan and Finney (MMF) methods in the soil loss estimation of sample slope segments, and relative comparison and suitability of both methods in the precise estimation of predicting soil loss.Keywords: Laterite, Gully, Rainsplash, Overland flow, USLE and MM

Noncovalent Interactions of Hydrated DNA and RNA Mapped by 2D-IR Spectroscopy

Biomolecules couple to their aqueous environment through a variety of noncovalent interactions. Local structures at the surface of DNA and RNA are frequently determined by hydrogen bonds with water molecules, complemented by non-specific electrostatic and many-body interactions. Structural fluctuations of the water shell result in fluctuating Coulomb forces on polar and/or ionic groups of the biomolecular structure and in a breaking and reformation of hydrogen bonds. Two-dimensional infrared (2D-IR) spectroscopy of vibrational modes of DNA and RNA gives insight into local hydration geometries, elementary molecular dynamics, and the mechanisms behind them. In this chapter, recent results from 2D-IR spectroscopy of native and artificial DNA and RNA are presented, together with theoretical calculations of molecular couplings and molecular dynamics simulations. Backbone vibrations of DNA and RNA are established as sensitive noninvasive probes of the complex behavior of hydrated helices. The results reveal the femtosecond fluctuation dynamics of the water shell, the short-range character of Coulomb interactions, and the strength and fluctuation amplitudes of interfacial electric fields.Comment: To appear as Chapter 8 of Springer Series in Optical Sciences: Coherent Multidimensional Spectroscopy -- Editors: Cho, Minhaeng (Ed.), 201

Pyridine C3-arylation of nicotinic acids accessible via a multicomponent reaction: an entry to all-substituted-3,4-diarylated pyridines

An efficient route for the synthesis of penta-substituted/functionalized-3,4-diarylated pyridines, biologically important templates, via pyridine C3-arylation of nicotinic acids has been developed. The poly-substituted nicotinic acid precursors were prepared by an established multicomponent condensation approach. This route shows an excellent opportunity for introducing versatile (hetero)aryls and other substituents/functionalities into the pyridine ring. Several of the synthesized compounds exhibited significant anti-proliferative properties

Combretastatin-Inspired Heterocycles as Antitubulin Anticancer Agents

Combretastatin (CA-4) and its analogues are undergoing several clinical trials for treating different types of tumors. In this work, the antiproliferative activity of a series of 2-aminoimidazole-carbonyl analogs of clinically relevant combretastatins A-4 (CA-4) and A-1 was evaluated using a cell-based assay. Among the compounds tested, C-13 and C-21 displayed strong antiproliferative activities against HeLa cells. C-13 inhibited the proliferation of lung carcinoma (A549) cells more potently than combretastatin A-4. C-13 also retarded the migration of A549 cells. Interestingly, C-13 displayed much stronger antiproliferative effects against breast carcinoma and skin melanoma cells compared to noncancerous breast epithelial and skin fibroblast cells. C-13 strongly disassembled cellular microtubules, perturbed the localization of EB1 protein, inhibited mitosis in cultured cells, and bound to tubulin at the colchicine site and inhibited the polymerization of reconstituted microtubules in vitro. C-13 treatment increased the level of reactive oxygen species and induced apoptosis via poly(ADP-ribose) polymerase-cleavage in HeLa cells. The results revealed the importance of the 2-aminoimidazole-carbonyl motif as a double bond replacement in combretastatin and indicated a pharmacodynamically interesting pattern of H-bond acceptors/donors and requisite syn-templated aryls

Drug-Clinical Agent Molecular Hybrid: Synthesis of Diaryl(trifluoromethyl)pyrazoles as Tubulin Targeting Anticancer Agents

Twenty-three combretastatin A-4 (CA-4) analogues were synthesized by judiciously incorporating a functional N-heterocyclic motif present in Celecoxib (a marketed drug) while retaining essential pharmacophoric features of CA-4. Combretastatin-(trifluoromethyl)pyrazole hybrid analogues, i.e., 5-trimethoxyphenyl-3-(trifluoromethyl)pyrazoles with a variety of relevantly substituted aryls and heteroaryls at 1-position were considered as potential tubulin polymerization inhibitors. The cytotoxicity of the compounds was evaluated using MCF-7 cells. Analog 23 (C-23) was found to be the most active among the tested compounds. It showed pronounced cytotoxicity against HeLa, B16F10, and multidrug-resistant mammary tumor cells EMT6/AR1. Interestingly, C-23 displayed significantly lower toxicity toward noncancerous cells, MCF10A and L929, than their cancerous counterparts, MCF-7 and B16F10, respectively. C-23 depolymerized interphase microtubules, disrupted mitotic spindle formation, and arrested MCF-7 cells at mitosis, leading to cell death. C-23 inhibited the assembly of tubulin in vitro. C-23 bound to tubulin at the colchicine binding site and altered the secondary structures of tubulin. The data revealed the importance of (trimethoxyphenyl)(trifluoromethyl) pyrazole as a cis-restricted double bond-alternative bridging motif, and carboxymethyl-substituted phenyl as ring B for activities and interaction with tubulin. The results indicated that the combretastatin(trifluoromethyl)pyrazole hybrid class of analogues has the potential for further development as anticancer agents

Origin of shape anisotropy effects in solution-phase synthesized FePt nanomagnets

Controlling the morphology of inorganic nanocrystals is important because many of their electronic attributes are highly sensitive to shape and aspect ratio. FePt nanocrystals have potential as advanced magnetic materials for ultrahigh-density memory. This is due to their high shape and/or magnetocrystalline anisotropy, which allows bits as small as 3 nm to be thermally stable over typical data storage periods of 10 years. Herein, nanocrystals were simply fabricated by simultaneous reduction of platinum acetylacetonate and thermal decomposition of iron pentacarbonyl in properly chosen conditions of solvent/surfactant proportions and temperature for rational design of their shape and magnetic properties. This work has combined magnetometry measurements and micromagnetic simulations to illustrate the role of the external shape on the rotation of the magnetization vector for colloidal assemblies. (C) 2011 American Institute of Physics. [doi:10.1063/1.3608109