Girish Kumar, K; Devala Rao, G; Chowdary, K P R(Indian Journal Of Pharmaceutical Sciences, February 7, 2001)
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Abstract:
Two simple and sensitive spectrophotometric methods(A and B) in the visible region have been developed for the determination of cefotaxime sodium (DFTS) in bulk and in dosage forms. Method A is based on the reaction of CFTS with nitrous acid under alkaline conditions to form a stable violet colored chromogen with absorption maximum of 560 nm and method B is based on the reaction of CFTS with1,10-phenanthroline and ferric chloride to form a red colored chromogen with the absorption maximum of 520 mm.The color obeyed Beer’s law in the concentration range of 100-500 µg/ml for method A and 1.6-16 µg/ml for method B, respectively.When pharmaceutical preparations containing CFTS were analysed, the results obtained by the proposed methods are in good agreement with the labeled amounts and are comparable with the results obtained using a UV spectrophotometric method.
Ferrospinels of nickel, cobalt and copper and their sulphated analogues were prepared by the room temperature coprecipitation
route to yield samples with high surface areas. The intrinsic acidity among the ferrites was found to decrease in
the order: cobalt> nickel> copper. Sulphation caused an increase in the number of weak and medium strong acid sites,
whereas the strong acid sites were left unaffected. Electron donor studies revealed that copper ferrite has both the highest
proportion of strong sites and the lowest proportion of weak basic sites. All the ferrite samples proved to be good catalysts
for the benzoy lation of toluene with benzoyl chloride. copper and cobalt ferrites being much more active than nickel ferrite.
The catalytic activity for benzoylation was not much influenced by sulphation, but it increased remarkably with calcination
temperature of the catalyst. Surface Lewis acid sites, provided by the octahedral cations on the spinel surface, are suggested
to be responsible for the catalytic activity for the benzoylation reaction.
Biju,M P; Pyroja,Sulainian; Rajeshkumar,Neelimmathara V; Paulose,C S(Department of Biotechnology, February 15, 2001)
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Abstract:
Gamma aminohutyric acid (GAB A.) receptor tunctionaI status was artaIV se(l in pa It ial hcpatcctoIn ised.II'II). lead
nitrate (LN) induced hyperplastic and N-nifrosodiethylantinc INDEAI treated nctplastic rat Iivers during peak DNA
synthesis. The high-affinity I'HJGALA binding significantly decreased in PII and NDEi\ rats and the receptor affinity
decreased in NDEA and increased in LN rats compared with control . in NDEA. displacement analysis of I'I IIGABA
with muscimol showed loss of low-allinity site and a shill of high-allinity cite towards low-allinity . ' 1 he affinity sites
shifted towards high-affinity in LN rats. 'file number of low-allinity 1'I Ilhicuc)lline receptors decreased cignilic:uttly
in NDEA and I'll whereas it increased in LN rats. (ir\Bi\t receptor :gunist. unrscinrul. disc dependcnllyinhihilcd
epidermal growth factor IEGI--) induced DNA synthesis :uul enhanced the tr:utsfnrnting grmvth )actor (Il I I'(il (tlI
mediated DNA synthesis suppression in prim:uy hepalucvte cultures . Our results suggest that GABA,t reccjhtor act
as an inhibitory signal fur hepatic cell prolifctatiun.
A novel method of blending natural rubber with polyvinylchloride in the latex
stage was developed, Dioctyl phthalate (DOP) and Amine terminated natural rubber
(ATNR) were used as plasticisers, for improving the mechanical properties of
these blends. Properties of the latex stage blends were compared with those of
dry blends. Latex stage blends showed superior mechanical properties compared
to the blends prepared in the dry state. The ageing resistance, oil resistance and
processability were found to be improved by latex stage blending.
Sunil K Narayanankutty(John Wiley & Sons. Inc., June 21, 2001)
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Abstract:
The effect of diphenylmethane diisocyanate
(MDI) -polyethyleneglycol (PEG) resin on the cure characteristics and mechanical
properties of nitrile rubber/whole tyre eclaim-short nylon fiber
composite-was studied. At a constant loading of 5 phr, the resin composition
was varied. The minimum torque .,id (maximum - minimum) torque increased
with isocyanate concentration. Scorch time and cure time showed a reduction on
introduction of bonding agent. Properties like tensile strength, tear strength, and
abrasion resistance increased with increase in MDI/PEG ratio, and these
properties are higher in the longitudinal direction of fiber orientation.
Compression set increased with isocyanate concentration and the resilience
remain unchanged.
Sunil K Narayanankutty(Taylor & Francis Inc., March 26, 2001)
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Abstract:
Cure characteristics and mechanical properties of styrene butadiene rubber
reclaimed rubber blends were studied. The blends showed improved processability,
as indicated by the minimum torque values. Cure characteristics like minimum
torque, (maximum-minimum) torque, cure time and cure rate decreased in the
presence of reclaimed rubber. Tensile strength, tear strength, elongation at break
were higher for blends. Resilience decreased with reclaim content. Compression set
and abrasion loss were higher in the blends.
Rani, Joseph(John Wiley & Sons, Inc., June 21, 2001)
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Abstract:
ABSTRACT: Polyaniline was synthesized by using ammonium persulfate initiator in the
presence of 1M HC1. It was dried under different drying conditions like room temperature
drying (for 48 h), oven drying (at 50-60°C for 8 h under a vacuum), and vacuum
drying (at room temperature for 16 h). The conductivities of these samples were
measured at microwave frequencies. These samples were also pelletized and the
measurements were repeated. The cavity perturbation technique was used for the
study.