84 research outputs found
Electrochemical Separation of Carrier-free Iron
The separation of vario us e lements by electrodeposition using a mercury cathode has b een presented in a summarised form1 • However, as stated by Lavrukhina such investigations, especially in the case of trace elements, have not been carried out systematically. Hovewer, it is well known that the d eposition of iron group elements onto a Hg-cath ode is followed by an overvoltage. A number of papers3 - 7 present the application of this method to various systems, but a method to be applied for the separation of trace amounts of iron from large amounts of manganese using a constant potential mercury cathode system has not been described as yet
The Precipitation of Rubidium and Ceasium with Silicotungstic Acid
The precipitation· of rubidium and ceasium with silicotungstic
a cid has been stu died w ith the aim of investigating such processes
as a possible separation method. The influence of hydrochloric acid,
ammonium chloride, and the aging of the precipitates was investigated.
The results show that there are diffe rences in the
precipitation of rubidium and ceasium with s ilicotungstic acid.
When accompanying ceasium, rubidium was found even in precipitates
under such experimental conditions for which it would not
precipitate itself. The results also indicate that precipitates formed
in the low concentration region of h ydrochloric acid are salts either
of rubidium or ceasium silicotungstate. At higher acid concentrations
there is a higher precipitation yield. This is due to the contributions
from two processes: precipitation and co -precipitation** . At higher
hydrochloric a cid concentrations, the precipitation of rubidium
or ceasium silicotungstate is followed by co-precipitation of rubidium
and ceasium. It is shown that rubidium can be removed
from rubidium-ceasium silicotungstates by an exchange reaction
The Debrisoft ® monofilament debridement pad for use in acute or chronic wounds: A NICE medical technology guidance
As part of its Medical Technology Evaluation Programme, the National Institute for Health and Care Excellence (NICE) invited a manufacturer to provide clinical and economic evidence for the evaluation of the Debrisoft ® monofilament debridement pad for use in acute or chronic wounds. The University of Birmingham and Brunel University, acting as a consortium, was commissioned to act as an External Assessment Centre (EAC) for NICE, independently appraising the submission. This article is an overview of the original evidence submitted, the EAC’s findings and the final NICE guidance issued. The sponsor submitted a simple cost analysis to estimate the costs of using Debrisoft® to debride wounds compared with saline and gauze, hydrogel and larvae. Separate analyses were conducted for applications in home and applications in a clinic setting. The analysis took an UK National Health Service (NHS) perspective. It incorporated the costs of the technologies and supplementary technologies (such as dressings) and the costs of their application by a district nurse. The sponsor concluded that Debrisoft® was cost saving relative to the comparators. The EAC made amendments to the sponsor analysis to correct for errors and to reflect alternative assumptions. Debrisoft® remained cost saving in most analyses and savings ranged from £77 to £222 per patient compared with hydrogel, from £97 to £347 compared with saline and gauze, and from £180 to £484 compared with larvae depending on the assumptions included in the analysis and whether debridement took place in a home or clinic setting. All analyses were severely limited by the available data on effectiveness, in particular a lack of comparative studies and that the effectiveness data for the comparators came from studies reporting different clinical endpoints compared with Debrisoft®. The Medical Technologies Advisory Committee made a positive recommendation for adoption of Debrisoft® and this has been published as a NICE medical technology guidance (MTG17).The Birmingham and Brunel Consortium is funded by NICE to act as an External Assessment Centre for the Medical Technologies Evaluation Programme
The Precipitation of Rubidium and Ceasium with Silicotungstic Acid
The precipitation· of rubidium and ceasium with silicotungstic
a cid has been stu died w ith the aim of investigating such processes
as a possible separation method. The influence of hydrochloric acid,
ammonium chloride, and the aging of the precipitates was investigated.
The results show that there are diffe rences in the
precipitation of rubidium and ceasium with s ilicotungstic acid.
When accompanying ceasium, rubidium was found even in precipitates
under such experimental conditions for which it would not
precipitate itself. The results also indicate that precipitates formed
in the low concentration region of h ydrochloric acid are salts either
of rubidium or ceasium silicotungstate. At higher acid concentrations
there is a higher precipitation yield. This is due to the contributions
from two processes: precipitation and co -precipitation** . At higher
hydrochloric a cid concentrations, the precipitation of rubidium
or ceasium silicotungstate is followed by co-precipitation of rubidium
and ceasium. It is shown that rubidium can be removed
from rubidium-ceasium silicotungstates by an exchange reaction
Antimicrobial activities of pomegranate rind extracts: enhancement by addition of metal salts and vitamin C
BACKGROUND: Punica granatum L. or pomegranates, have been reported to have antimicrobial activity against a range of Gram positive and negative bacteria. Pomegranate formulations containing ferrous salts have enhanced although short-term, antibacteriophage activities which are rapidly diminished owing to instability of the ferrous combination. The aim of this study was to determine the antimicrobial activities of combinations of pomegranate rind extracts (PRE) with a range of metals salts with the added stabiliser vitamin C. METHODS: PRE solutions, prepared by blending rind sections with distilled water prior to sterilisation by autoclaving or filtration, were screened with a disc diffusion assay using penicillin G as a control. Suspension assays were used to determine the antimicrobial activities of PRE alone and in combination with salts of the following metals; Fe (II), Cu (II), Mn (II) or Zn (II), and vitamin C, against a panel of microbes following exposure for 30 mins. The test organisms included Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Proteus mirabilis. RESULTS: The screening assay demonstrated that PRE exhibited activity against the Gram positive organisms at 24 h with no observable effect on any of the Gram negative bacteria. However, after 12 h, zones of inhibition were only observed for Ps. aeruginosa. In contrast, using the suspension assay, addition of Cu (II) salts to PRE solutions extended the activities resulting in no detectable growth being observed for the PRE/Cu (II) combination against E. coli, Ps. aeruginosa and P. mirabilis. Minimal antimicrobial activity was observed following incubation with Fe (II), Mn (II) or Zn (II) salts alone or in combination with PRE against any of the organisms in the test panel. The addition of vitamin C markedly enhanced the activities of both PRE/Fe (II) and PRE/Cu (II) combinations against S. aureus. CONCLUSION: This is the first report demonstrating the enhanced efficacy of PRE/metal salt combinations in the presence of the stabilising agent vitamin C, to which all isolates were sensitive with the exception of B. subtilis. This study has validated the exploration of PRE along with additives such as metal salts and vitamin C as novel antimicrobial combinations
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