Depolymerization and chemical modification of lignite coal byPseudomonas cepacia strain DLC-07

Applied Biochemistry and Biotechnology - Coal metabolizingPseudomonas cepacia DLC-07 was isolated from soil and shown to use soluble lignite coal as a carbon/energy source.Pseudomonas modified coal...     

Investigations of regio- and stereoselectivities in the synthesis of cytotoxic isoxazolidines through 1,3-dipolar cycloadditions of nitrones to dipolarophiles bearing an allylic oxygen

Regio- and stereoselectivities in cycloadditions of nitrones to dipolarophiles bearing an allylic oxygen, which furnishes substituted-isoxazolidine analogs of the furanose ring of nucleosides, have been investigated. Although the obtained regioselectivities are anticipated, a rationalization of the preferred formation of endo-cycloadducts necessitates the involvement of an allylic oxygen in secondary interaction. The obtained isoxazolidines display cytotoxic activities against a number of human cancer cell lines.     

Pseudohalide derivatives of (η -cyclopentadienyl-η-methylcyclopentadienyl) titanium (IV)

Summary Pseudohalide complexes of the (-cpL)TiXZ type (where cp = cyclopentadienyl, L = -McCs₅-H₄ and X = N3, NCS, NCO or NCSe) have been prepared in aqueous and nonaqueous media and characterized by elemental analyses, i.r. and n.m.r. spectroscopy. I.r. spectroscopy shows that NCS, NCO and NCSe are bonded to the titanium atom through nitrogen in these complexes which are thus true isothiocyanato, isocyanato and isoselenocyanato derivatives respectively.     

Antimicrobial investigation of Linum usitatissimum for the treatment of acne

Light petroleum, dichloromethane and methanolic extracts of Linum usitatissimum were investigated using GC/MS. The main components of three sequential extracts were methyl linolenate (11.9-33.9%) and methyl linoleate (3.4-9.1%). Components possessing antimicrobial activity against acne causing bacteria, namely alpha-linolenic acid (7.0 -7.1%), alpha-terpinene (1.7-3.1%), terpinen-4-ol (1.3-4.6%), 4-cymene (1.6-7.1%) and alpha-pinene (1.1%), were found in varying amounts. Antimicrobial screening indicated that the light petroleum extract was more active against aerobic and anaerobic test strains with a MIC value of 1.25 mg/mL and a MBC of 2.5 mg/mL against S. aureus and P. acnes. A MIC of 2.5 mg/mL was observed against S. epidermidis.     

Synthesis and characterization of K2NiF4-type phases Ln0.5Sr1.5Mn0.5Fe0.5O4 (Ln = La, Nd, Gd, and Dy)

A systematic investigation of layered perovskite oxides with general formula Ln_0.5Sr_1.5Mn_0.5Fe_0.5O₄ (Ln?=?La, Nd, Gd, and Dy) has been undertaken mainly to understand their structural, magnetic, as well as electrical behavior. The materials were prepared by the ceramic method. X-ray data have been analyzed by using program Checkcell and the variations of various parameters are explained. It has been concluded that not only A-site cation radius, <r _A>, but also the size variance factor (σ ²) influence electrical and magnetic properties. A systematic study of electrical resistivity of all the four materials was undertaken as a function of temperature to understand the conduction mechanism. On analyzing the electrical resistivity data, it has been concluded that variable range hopping model is found to fit well. The magnetic studies suggest that the phases are antiferromagnetic and this behavior could arise from Mn⁴⁺–O–Mn⁴⁺, and Fe³⁺–O–Fe³⁺ superexchange interaction.     

Preparation and characterization of some stereochemically rigid seven-coordinate η-cyclopentadienyltris(N,N-dialkyldithiocarbamato)hafnium(IV) complexes

Summary N,N-Dialkyldithiocarbametohafnium(IV) complexes of the type -CpHf(S₂CNR₂)₃, (R = Me or Et) have been prepared in nonaqueous media by reacting dichlorodicyclopentadienylhafnium(IV) with sodium salts of substituted dithiocarbamic acids. Conductance and i.r. studies show that these complexes are nonelectrolytes in which all of the dithiocarbamate ligands are bidentate. A coordination number of seven may be assigned to hafnium(IV) in these complexes, 'H n.m.r. spectra of the complexes in CDCI₃ at ambient temperature (30°) indicate that the metal centered rearrangement and the S₂C N bond rotation are both slow on the n.m.r. time scale. A capped octahedron configuration is suggested for these complexes.Author to whore all correspondence should be addressed.     

Conditionally Negative Definite Functions

Let \(f:[0,\infty )\rightarrow [0,\infty )\) be an operator monotone function and \(g: \mathbb {R}\rightarrow [0,\infty )\) be a conditionally negative definite(in short cnd) function. We obtain that \(f\circ g:\mathbb {R}\rightarrow [0,\infty )\) is also conditionally negative definite. This generalizes and subsumes several existing results. A versatile direct connection between cnd functions and functions having Weierstrass factorization is established and consequently a reasonable account for cnd functions is presented.     

Hydrothermal synthesis of manganese oxide and nitrogen doped graphene (NG-MnO2) nanohybrid for visible light degradation of methyl orange dye

MnO₂ nanoparticles and its nanocomposite with nitrogen-doped graphene (NG) have been fabricated via simple hydrothermal synthesis procedure using water as a solvent. X-ray diffraction (XRD) analysis of the as-prepared samples was used to ascertain the phase purity and crystallite size. Field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) were employed to study the surface features and particle size of the synthesised samples. The photocatalytic ability of the methyl orange (MO) dye with bare MnO₂ and its hybrid with nitrogen-doped graphene (NG-MnO₂) wer compared with visible light prompted degradation of the dye in absence of these catalysts. The prepared nanohybrid (NG-MnO₂) showed improved photocatalytic efficacy as compared to the pure MnO₂ nanoparticles. The strong ferromagnetic character of nanohybrid helps in easy separation of catalyst even with a bar magnet.