A new method for preparation of silica potassium cobalt hexacyanoferrate composite ion exchanger from silica sol

A new method for the preparation of porous silicapotassium cobalt hexacyanoferrate (SiO₂ ^.KCoFC) composite from silica sol is described. Silica sol was first gelled with K₄Fe(CN)₆ solution. Then the resulting hydrogel, SiO₂ ^.K₄Fe(CN)₆ was reacted with Co(NO₃)₂ solution in acetone to give the composite SiO₂ ^.KCoFC hydrogel. The empirical formula of KCoFC in the composite was found to be K₁.₆₉Co _0.93Fe(CN)₆. The removal efficiency of the composite for Cs was judged by measuring its distribution coefficient, K _d in 1M HCl solution containing 10 ppm Cs. The K _d of Cs was found to be 5.73^.10⁵ ml/g-composite.     

An HPTLC Method for the Simultaneous Analysis of Compactin and Citrinin in Penicillium citrinum Fermentation Broth

JPC – Journal of Planar Chromatography – Modern TLC - A simple and precise high-performance thin-layer chromatographic (HPTLC) method has been established for simultaneous analysis of...     

Development of an HPTLC‐based diagnostic method for invasive aspergillosis

A rapid, sensitive and specific high‐performance thin‐layer chromatographic (HPTLC) method was developed and validated for determination of gliotoxin in Aspergillus infected immunocompromised patients with invasive aspergillosis (IA). Densitometric analysis of gliotoxin was carried out in the absorbance mode at 254 nm after single‐step extraction with chloroform. The method uses TLC aluminum plates pre‐coated with silica gel 60F‐254 as a stationary phase and toluene–isoamyl alcohol–methanol (10:0.5:0.5, v/v/v) as mobile phase, which gives compact spot of gliotoxin (R_f = 0.51). The calibration curve was linear (r² ≥ 0.994) between peak area and concentration in the tested range of 100–1000 ng spot^?1 with minimum detectable range 0.025 ng μ^?1 of serum sample. The mean ± SD value of slope and intercept of the standard chromatogram of gliotoxin were found to be 523.2 ± 1.555635 and 915.8 ± 30.68843, respectively. The developed method is simple, rapid, precise and less costly than earlier diagnostic methods, and different serum samples can be run on a single TLC plate for comparative analysis. The proposed method can be used to analyze gliotoxin in patient serum for easy, rapid and cost‐effective diagnosis of IA. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis and Characterization of Antimony(III) Complexes of Thioamides,and Crystal Structure of {[Sb(Imt)2Cl2]2((2‐Imt)}Cl2(Imt=Imidazolidine‐2‐thione)

Antimony(III) complexes of thioamides [thioamides=thiourea (Tu), N,N′‐dimethylthiourea (Dmtu), tetramethylthiourea (Tmtu), imidazolidine‐2‐thione (Imt) and diazinane‐2‐thione (Diaz)] with the general formulae, Sb(thione)_nCl₃ (n=1, 2, 2.5, 3) were prepared and characterized by elemental analysis, IR and NMR (¹H, ¹³C) spectroscopic methods. The spectral data of the complexes are consistent with the coordination of the thiones to antimony(III). The crystal structure of one of them, {[Sb(Imt)₂Cl₂]₂(μ₂‐Imt)}Cl₂ ( 1 ), was determined by X‐ray crystallography, which shows that the complex is dinuclear consisting of two [Sb(Imt)₂Cl₂] units bridged by an Imt molecule. In 1 , the antimony atom is bonded to two chlorine atoms, two sulfur atoms of coordinated Imt molecules and one sulfur atom of a bridging Imt molecule. The antimony environment can be considered to be distorted octahedral with one Cl^? ion weakly bound to antimony.     

Acylation of Cellulose with N,N′‐Carbonyldiimidazole‐Activated Acids in the Novel Solvent Dimethyl Sulfoxide/Tetrabutylammonium Fluoride

Summary: Carboxylic acids were efficiently activated with N,N′‐carbonyldiimidazole (CDI) and applied for the acylation of cellulose under homogeneous conditions using dimethyl sulfoxide (DMSO)/tetrabutylammonium fluoride trihydrate (TBAF) as solvent. The simple and elegant method is a very mild and easily applicable tool for the synthesis of pure aliphatic, alicyclic, bulky, and unsaturated cellulose esters with degrees of substitution of up to 1.9. Products are soluble in organic solvents, e.g., DMSO or N,N‐dimethylformamide (DMF). The cellulose esters were characterized by elemental analysis, FT‐IR, ¹H and ¹³C NMR spectroscopy and show no impurities or substructures resulting from side reactions.

The esterification of cellulose using carboxylic acids activated in situ with N,N′‐carbonyldiimidazole.     

Transverse Momentum Distributions of Pions,Kaons and Protons in p − p Interactions at 2.76 TeV

The spectra and particle yield ratios of π^±, K^± meson, protons and anti-protons in proton-proton (p − p) interactions at \( \sqrt{s}=2.76 \) TeV are presented. CRMC generators: EPOS-LHC, EPOS1.99 and QGSJETII-04, are used for simulations and the results are compared with LHC-CMS experimental data. The particles are identified in the transverse momentum range of p_T ≈ 0.1 − 1.7 GeV/c and absolute rapidity, ∣y∣ < 1. In simulation, same cuts in p_T and y are used as in the experiment. The EPOS1.99 model predicts the data well as compared to the other two models, which predict in some of the p_T regions only. The different models used could not effectively describe the experimental data in all p_T range.

     

Distributions of the Transverse Momentum and Pseudorapidity of Charged Particles in pp Collisions at 0.9 TeV

JETP Letters - We have studied the charged particles spectra for the pseudorapidity region of ∣η∣ &lt; 2.5, the multiplicity of charged particles, its dependence on pT as well...     

Quantification of lipid modified estrogenic derivative (ESC8) in rat plasma by LC‐MS: application to a pharmacokinetic study

A lipid‐conjugated, estrogenic derivative molecule, ESC8, compared with other estrogenic molecules, encourages cell death in both ER‐positive and ER‐negative breast cancer cells. A rapid and highly sensitive assay method has been developed and validated for the estimation of a ESC8 in rat plasma using liquid chromatography coupled with mass spectrometry under positive‐ion mode with electrospray ionization. The sample process includes using methanol for precipitation of ESC8 and dextromethorphan (internal standard, IS) from plasma. Chromatographic separation was achieved with methanol–water–formic acid (70:30:0.1% v/v/v) pumped at a flow rate of 0.3mL/min and a C₁₈ column (50 × 2.1 mm i.d., 1.7 μm particle size) with a total run time of 5 min. The m/z ions monitored were 568.5 and 272.1 for ESC8 and IS, respectively. The lower limit of quantitation achieved was 1.08 ng/mL and linearity was observed from 5 to 500 ng/mL. The intra‐ and inter‐day precisions were <4%. The proposed method was successfully applied to a preliminary pharmacokinetic study of ESC8 liposomal formulation following an intraperitoneal administration of 3.67 mg/kg in rats. The concentrations of ESC8 in plasma were quantifiable up to 36 h. The peak concentration of ESC8 was found to be 110.72 ng/mL, the area under the concentration–time curve was 1625.23ng/mL h and the half‐life was 11.72 h.     

Applying a new method for analyzing experimental data on nuclear reactions at high energies

A new statistical method is proposed for the analysis of experimental data obtained in nucleus-nucleus collisions at high energies which borrows from ideas developed using the Random Matrix Theory. The method allows us to detect regions with correlation effects in the momentum distributions of secondary particles.     

Hydroxypropylcellulose-aceclofenac conjugates: high covalent loading design, structure characterization, nano-assemblies and thermal kinetics

This article presents synthesis of novel macromolecular prodrugs of aceclofenac (an anti-inflammatory drug) onto hydroxypropylcellulose (HPC). The HPC-aceclofenac conjugates were prepared using an acylating agent 1,1′-carbonyldiimidazole (CDI) under homogenous reaction conditions. Aceclofenac was first activated by using CDI to form its N-acylimidazole. The N-acylimidazole of aceclofenac was then reacted with HPC polymer at 80 °C for 24 h. Highly pure prodrugs of aceclofenac were synthesized with a wide range of moderate to high degree of substitution (DS 0.41–2.12) as calculated by ¹H NMR spectroscopy. The UV spectroscopic analysis has also revealed that the active drug aceclofenac was found in different conjugates from 28 to 67 mg/100 mg of HPC-aceclofenac conjugates which are in good agreement with DS calculated by ¹H NMR spectroscopy. The gel permeation chromatography showed unimodal absorption that indicates no significant degradation in polymer chains during the reaction. The macromolecular prodrugs of aceclofenac were characterized using different spectroscopic and chromatographic techniques. The thermal analysis has revealed that HPC-aceclofenac conjugates (prodrugs) are 92 and 96 °C more stable than pure aceclofenac regarding their initial (Tdi) and maximum degradation temperatures (Tdm), respectively. The activation energy (Ea) and frequency factor (Z) of the degradation reactions were evaluated using Friedman, Broido and Chang methods. Degradation followed first order (n) kinetics. Transmission electron microscopy has revealed the formation of sponge like nano aggregates with population size distribution of around 80–150 nm.