Antioxidant attributes of tea in North Bengal, India: Relation with its principal constituents and properties of soil

This study was performed in 18 tea gardens in North Bengal, India, from 2012 to 2017. The data were pooled to investigate the relationship with soil physico-chemical properties, phyto-constituents, antioxidant attributes and age of the tea bushes and principal component analysis (PCA). PCA and dendro-hit maps were also performed with each region. The 28 principal components were chosen based on their eigen values, explaining the total data variance for tea in Dooars, Terai and Darjeeling hill. In almost all cases, composite soil physico-chemical attributes were heavily loaded on the second principal component and clustered, as visual evidenced by the dendro-hit map. Different attributes were significantly correlated each other in case of Terai i.e. (value of “r’’ at P<0.01 level) clay fraction (0.778), electrical conductivity (0.618), N (0.777), S (0.748), P (0.514 ppm), flavour index (0.918), total polyphenol (0.687) DPPH (0.794), nitric oxide (0.913), anti-lipid peroxidation (0.717) and metal chelating (0.665). In Dooars region, attributes were significantly correlated with silt (0.718), pH (0.875), P (0.615 ), chloride (0.858), TP (0.776), flavonol (0.923), quinone (0.666), tannins (0.865), DPPH (0.536), superoxide (0.576), ABTS (0.520) and MC (0.777) and in the case of Darjeeling hills, attributes were highly correlated with clay (0.812), sand (0.818), silt fraction (0.974), K (0.932), S (0.999), MC of soil (0.671), TP (0.853), tannins (0.912), DPPH (0.624), ABTS (0.661) and MC (0.633) repectively

Giant Magnetoimpedance (GMI) Effect and Field Sensitivity of Ferrofluid Coated Co66Fe2Si13B15Cr4 Soft Magnetic Amorphous Microwire

AbstractCo66Fe2Si13B15Cr4 based amorphous microwire was developed at the laboratory using in-water quenching apparatus. The field sensitivity of the wire was enhanced when coated with ferrofluids. The presence of coating also decreased the frequency of the magnetising field 5MHz to 1MHz at which the maximum GMI ratio observed

An unusual iminoacylation of 2-amino pyridyl thiazole: Synthesis, X-ray crystallography and DFT study of copper(II) amidine complexes and their cytotoxicity, DNA binding and cleavage study

Insertion of acetonitrile in the exocyclic NH2 group of the thiazole unit of 2-amino-4-(2-pyridyl)thiazole (HL) in the presence of copper chloride results in the formation of the monomeric amidine complex [Cu{LC(Me)double bondNH)}Cl2] (1). The same reaction of HL and copper(II) perchlorate yields the complex [Cu(HL)2](ClO4)2 (2), without acetonitrile insertion. However, the presence of a spacer donor, e.g. pyrazine, in the reaction medium results in the formation of a dinuclear amidine derivative, [(ClO4){LC(Me)double bondNH}Cu(μ-pyrazine)Cu{LC(Me)double bondNH}(ClO4)] (ClO4)2 (3). Complexes 1 and 3 are the first examples of copper assisted iminoacylation of 2-amino pyridylthiazole derivatives, confirming a nitrile to amidine transformation. The new complexes were characterized by single crystal X-ray crystallography, cyclic voltammetry and a DFT study. The complexes have a potential cytotoxic effect in human monocytic cells (U937) with IC50 values ranging from 0.84 to 4.5 μM. Significant necrotic activities are ascertained by a lactate dehydrogenase (LDH) enzyme release assay. The interaction with calf thymus (CT) DNA shows the binding constant (Kb) values are ∼104 M−1. The chemical nuclease activity of 1, 2 and 3 result in 65, 99 and 80% relaxation of supercoiled DNA at 10 μM in the presence of glutathione (GSH, 1 mM), respectively. The study with radical scavengers proved that a hydroxyl or singlet oxygen-like species is responsible for the DNA degradation.publishe

Synthesis, characterization and antimicrobial activities of Co(III) and Ni(II) complexes with 5-methyl-3-formylpyrazole-N(4)-dihexylthiosemicarbazone (HMPzNHex2) : X-ray crystallography and DFT calculations of [Co(MPzNHex2)2]ClO4·1.5H2O (I) and [Ni(HMPzNHex2)2]Cl2·2H2O (II)

Manan Saha is thankful to the U.G.C., Govt. of India for providing financial support in the form of Rajiv Gandhi National Fellowship (Number and date of award letter: F1-17.1/2013-14/RGNF-2013-14-SC-WES- 51398/(SA-III/Website); 06/02/2014). N.C. Saha is thankful to the University of Kalyani for financial assistance received in the form of Personal Research Grant.A new pyrazole containing ligand, 5-methyl-3-formylpyrazole-N(4)-dihexylthiosemicarbazone (HMPzNHex2), and a host of its cobalt(III) and nickel(II) complexes, [Co(MPzNHex2)2]X·mH2O and [Ni(HMPzNHex2)2]X2·nH2O (X= Cl, Br, ClO4, BF4 and NO3; m = 0 for Cl, Br, BF4 & NO3 and 1.5 for ClO4; n = 0 for Br, ClO4, BF4 & NO3 and 2 for Cl), respectively, have been synthesized and characterized by elemental analyses, magnetic measurements (polycrystalline state), 1H NMR (for the ligand and its Co(III) complexes), electronic and IR spectral parameters. All the reported Co(III) and Ni(II) complexes are cationic in nature and behaving as 1:1 and 1:2 electrolytes, respectively, in MeOH. Electronic spectral data of the complexes categorize them as havingdistorted octahedral coordination geometry. IR spectral features (4000-/450 cm-1) specify a monodeprotonated / neutral tridentate (NNS) function of the ligand, HMPzNHex2 coordinating to the Co(III) / Ni(II) via the pyrazolyl (tertiary) ring nitrogen, azomethine nitrogen and thiolato / thioketo sulfur atom. 1H NMR spectral data (in CDCl3 at 400 MHz) for the primary ligand and those of its Co(III) complexes are in agreement with the proposition of bonding sites evidenced from IR data. The single crystal x-ray data of I (C2/c (#15); monoclinic) and II (P-1 (#2); triclinic) have confirmed a CoN4S2 and a NiN4S2 octahedral coordination, respectively. The pair of monoprotic / neutral coordinating ligands is more or less orthogonal to each other in the complex species. The data obtained from DFT calculations are reasonably in agreement with the UV-Vis spectral assignment and the structures of the complex species. Although the ligand and the tested metal ion complexes are capable of inhibiting microbial growth, the cobalt complexes can be promoted as better antimicrobial agents.PostprintPeer reviewe

Improvement in transportability of Indian heavy crude oil using novel surfactant

262-270Rheological behaviour of Indian heavy crude oil has been investigated using novel surfactant, Brij 30. The results have been compared with addition of dilutants namely mineral oil and 3-pentanol. The effect of addition of additives on viscosity, yield stress and viscoelastic behaviour including non-Newtonian viscosity, elastic modulus, loss modulus, phase angle and complex viscosity and thixotropy are studied. The most efficient additive among the three is found to be Brij 30. Addition of 10% 3-pentanol, mineral oil and Brij-30 reduce the viscosity of crude oil by 79.75, 42.1 and 87%, respectively at 25°C. Yield stress reduces by 98% after addition of Brij 30. Thixotropotic area for crude is reduced to 9.11 kPa/s from 326.53 kPa/s after addition of 10% Brij 30. Brij-30 dropped interfacial tension of crude to a greater extent compared to other additives. FTIR studies show disappearance of C=O, C=C and NO2 groups in surfactant-crude mixture which indicate effectiveness of the Brij-30 surfactant. Brij 30’s efficiency as a surfactant may be employed to improve rheological characteristics of heavy crude oil for proper pipeline transportation

Modeling and analysis of an extrinsic Fabry-Perot interferometer cavity

A schematic representation of optical feedback between two resonator mirrors undergoing a phase shift each round trip as a function of the separation of the mirrors is studied. A transfer function modeling of the extrinsic Fabry-Perot interferometer (EFPI) is presented. Nyquist analysis has been used to forecast the operational stability and possibility of interference in an EFPI. The analysis with two perfectly parallel surfaces of the cavity shows efficient interference. The performance when there is some tilt between the two mirrors in the cavity is also studied and is presented. In this case some restricted interference is found. (c) 2005 Optical Society of America

Novel Nanosomes for Gene Delivery to Plasmodium Falciparum-Infected Red Blood Cells.

Malaria threatens millions of people annually and is a burden to human health and economic development. Unfortunately in terms of disease control, no effective vaccines are available and the efficacy of treatment is limited by drug resistance. Genetic manipulation in Plasmodium falciparum is hampered due to the absence of robust methods for genetic analyses. Electroporation-based transfection methods have allowed the study of gene function in P. falciparum, with low efficiency. A lipid nanoparticle was developed that allowed nuclear targeting of pDNA with increased efficiency in reporter assay, compared to traditional electroporation method. This method has for the first time, facilitated transfection using both circular and linear DNA in P. falciparum thereby serving as an alternative to electroporation with an increase in transfection efficiency. Availability of a robust method for functional genomic studies in these organisms may be a catalyst for discovery of novel targets for developing drugs and vaccines

NUMERICAL INVESTIGATION OF HEAT TRANSFER UNDER IMPINGING ANNULAR JETS

In the present work, numerical investigations have been done to predict the transport phenomena and heat transfer characteristics of laminar annular jets impinging on a surface. For analysis purpose, the characteristics of an annular jet has been compared with that of a circular jet at the same Reynolds number with same amount of mass and momentum efflux at the nozzle exit. The Reynolds number of the jet is defined on the basis of width of the annular part. The distribution pattern of the Nusselt number over the impinging surface scales with Re0.54.&nbsp

(+)-3',4'-dihydrostephasubine, a bisbenzylisoquinoline alkaloid from Stephania hernandifolia

A new bisbenzylisoquinoline alkaloid has been isolated from the stems of Stephania hernandifolia and its structure established as (+)-3',4'-dihydrostephasubine. This is accompanied by the known alkaloid (+)-stephasubine (+)-Epistephanine has been found in the roots of the plant