2,329 research outputs found
Good vibrations: Do electrical therapeutic massagers work?
Health, leisure and beauty activities are increasing in popularity, with a particular emphasis on self-help and alternative health practices. One product type that has increased sales with this expansion is the hand-held electric massager. These are products that use vibration as a means of alleviating muscular strains and pains, as well as promoting relaxation. Paradoxically, these products are extremely popular as gifts, but are soon discarded. A multi-disciplinary research team was commissioned by a British manufacturer of electrical consumer products to investigate user attitudes and perceptions of existing massagers, to identify areas of user dissatisfaction. The manufacturer was also concerned about a possible stigma attached to these products because of an association with sex aids. This paper provides an
account of the perceptions of both consumers and therapists regarding the use of these products. Identifying the differences between the perceptions of consumers and therapists should help provide a basis for effective integration
of user needs, manufacturer requirements, designers’ skills and sound therapeutic practice. The results provide insight to support the development of more effective hand-held massagers
Failure of non-vacuum steam sterilization processes for dental handpieces
Background:
Dental handpieces are used in critical and semi-critical operative interventions. Although a number of dental professional bodies recommend that dental handpieces are sterilized between patient use there is a lack of clarity and understanding of the effectiveness of different steam sterilization processes. The internal mechanisms of dental handpieces contain narrow lumens (0·8-2·3mm) which can impede the removal of air and ingress of saturated steam required to achieve sterilization conditions.
Aim:
To identify the extent of sterilization failure in dental handpieces using a non-vacuum process.
Methods:
In-vitro and in-vivo investigations were conducted on commonly used UK benchtop steam sterilizers and three different types of dental handpieces. The sterilization process was monitored inside the lumens of dental handpieces using thermometric (TM) methods (dataloggers), chemical indicators (CI) and biological indicators (BI).
Findings:
All three methods of assessing achievement of sterility within dental handpieces that had been exposed to non-vacuum sterilization conditions demonstrated a significant number of failures (CI=8/3,024(fails/n tests); BI=15/3,024; TM=56/56) compared to vacuum sterilization conditions (CI=2/1,944; BI=0/1,944; TM=0/36). The dental handpiece most likely to fail sterilization in the non-vacuum process was the surgical handpiece. Non-vacuum sterilizers located in general dental practice had a higher rate of sterilization failure (CI=25/1,620; BI=32/1,620; TM=56/56) with no failures in vacuum process.
Conclusion:
Non-vacuum downward/gravity displacement, type-N steam sterilizers are an unreliable method for sterilization of dental handpieces in general dental practice. The handpiece most likely to fail sterilization is the type most frequently used for surgical interventions
Prevalence, correlates, effects and detection of left ventricular systolic dysfunction in an urban population
The prevalence of chronic heart failure (CHF) in most epidemiological studies
has been determined by using clinical criteria.In this thesis, in contrast, left ventricular systolic function was assessed
objectively by echocardiography in a cross -sectional survey of 2000 men and
women aged 25 -74, randomly sampled from a geographical area. Left
ventricular ejection fraction (LVEF) was measured using the Biplane
Simpson's Rule Method. Its aims were to document the prevalence of both
symptomatic and asymptomatic left ventricular systolic dysfunction; ascertain
the correlates of left ventricular systolic dysfunction; assess its effects on
effort capacity; determine the usefulness of the natriuretic peptides in
detecting systolic dysfunction; and to explore the possibility of a genetic
component to left ventricular systolic dysfunction by examining the
relationship between left ventricular systolic dysfunction and the angiotensinconverting enzyme insertion /deletion polymorphism (ACE I /D).In the 1640 subjects who attended (83%), the mean left ventricular ejection
fraction was 47.3%. The prevalence of `definite' left ventricular systolic
dysfunction (a LVEF ≤30%) was 2.9%: it was 0.7% in men aged 35-44 years
and 6.4% in men >65 years being also higher in men (4%) than women (2%).
One point five percent (1.5%) had symptomatic left ventricular systolic
dysfunction and 1.4% asymptomatic left ventricular systolic dysfunction.In those with left ventricular systolic dysfunction, 83% had evidence of
ischaemic heart disease (IHD), in contrast to 21% of those without left
ventricular systolic dysfunction (p<0.001). Hypertension was more common
in those with an abnormal ejection fraction (60% compared to 22%), p <0.001)
but hypertension unaccompanied by IHD was not significantly more common
in those with left ventricular systolic dysfunction.Left systolic ventricular dysfunction was associated with a significant
reduction in exercise duration. In subjects in whom this was asymptomatic
there was a trend towards decreased effort capacity.Plasma concentrations of the natriuretic peptides were significantly higher in
those with left ventricular systolic dysfunction (the median concentration
(interquartile range) of N-ANP was 2.8 [1.8,4.6] ng /ml and BNP; 24 [18,33]pg/ml) than in those without (N-ANP; 1.3[0.9,1.8] ng/ml and BNP; 7.7pg/mI[3.4,13], p <0.001). The area under the Receiver Operator
Characteristic Curves (SD) was greater using BNP; 0.88 (0.03) for all, 0.841
(0.03) in those with IHD, 0.86(0.03) for subjects ≥55 years and 0.84 (0.04) for
those ≥55 years with IHD. The same areas under the curve for N-ANP were
0.75(0.05), 0.71(0.05), 0.72 (0.05) and 0.70 (0.06), respectively. A BNP
concentration of ≥17.9pg /ml gave a sensitivity of 77% (specificity 87 %) for
detecting left ventricular systolic dysfunction in all subjects, improving to 92%
(specificity 72 %) when the analysis was restricted to individuals ≥ 55 with
IHD.The DD genotype of the ACE I/D polymorphism was significantly more
common in subjects with electrocardiographic evidence of myocardial
infarction (MI) or major ischaemia. (Using II as a reference, the odds ratios
normal versus major ischaemia or MI were: DD 1.53, ID 1.18:p =0.03 for
10
trend). In older patients (≥51 yr.) with an ECG MI or major abnormality, LVEF
was higher in those with the DD genotype (LVEF%: DD 44.6, ID 42.9, II
40;p <0.02). LVEF was also greater in older patients with a systolic blood
pressure (SBP) > than the median value (LVEF%: DD 47.5, ID 45.8, Il 44.6;
p= 0.012).This work has shown that left ventricular systolic dysfunction is at least as
twice as common than previous studies based on clinical criteria of CHF
would suggest; about half is asymptomatic. Only 18% of subjects with
definite left ventricular systolic dysfunction were taking an ACE inhibitor. Its
main risk factors are IHD and hypertension in the presence of IHD; screening
such high risk groups for left ventricular systolic dysfunction is worthy of
consideration. Using a test such as BNP and targetting its use to individuals
at high risk would lead to the identification of many more patients with left
ventricular systolic dysfunction and, therefore, to the uptake of effective
treatment. It would also lead to a more cost effective use of further
investigation.This thesis also provides a mechanistic insight into the development of left
ventricular systolic dysfunction by suggesting that while the DD genotype
confers a higher risk of MI, it is associated with better preservation of LV
function post MI, possibly by enabling more adequate compensatory
hypertrophy. The ACE gene I/D polymorphism may, therefore, have a bidirectional importance in determining both the risk of MI and post MI LV
systolic dysfunction
Investigating steam penetration using thermometric methods in dental handpieces with narrow internal lumens during sterilizing processes with non-vacuum or vacuum processes
Background:
Dental handpieces are required to be sterilized between patient use. Vacuum steam sterilization processes with fractionated pre/post-vacuum phases or unique cycles for specified medical devices, are required for hollow instruments with internal lumens to assure successful air removal. Entrapped air will compromise achievement of required sterilization conditions. Many countries and professional organisations still advocate non-vacuum sterilization processes for these devices.
Aim:
To investigate non-vacuum downward/gravity displacement, type-N steam sterilization of dental handpieces, using thermometric methods to measure time to achieve sterilization temperature at different handpiece locations.
Methods:
Measurements at different positions within air turbines were undertaken with thermocouples and dataloggers. Two examples of commonly used UK benchtop steam sterilizers were tested; a non-vacuum benchtop sterilizer (Little Sister 3, Eschmann, UK) and a vacuum benchtop sterilizer (Lisa, W&H, Austria). Each sterilizer cycle was completed with three handpieces and each cycle in triplicate.
Findings:
A total of 140 measurements inside dental handpiece lumens were recorded. We demonstrate that the non-vacuum process fails (time range 0-150 seconds) to reliably achieve sterilization temperatures within the time limit specified by the International standard (15 seconds equilibration time). The measurement point at the base of the handpiece failed in all test runs (n=9) to meet the standard. No failures were detected with the vacuum steam sterilization type B process with fractionated pre-vacuum and post-vacuum phases.
Conclusion:
Non-vacuum downward/gravity displacement, type-N steam sterilization processes are unreliable in achieving sterilization conditions inside dental handpieces and the base of the handpiece is the site most likely to fail
Ruthenium phthalocyanine and naphthalocyanine complexes: Synthesis, properties and applications
This article reviews the synthesis of ruthenium phthalocyanine and naphthalocyanine complexes highlighting important advances, and examines their physical properties and applications. © 2006 Elsevier B.V. All rights reserved
Aqueous pathways for the formation of zinc oxide nanoparticles
We examine the effect of reactant concentrations, temperatures and feeding methods on the morphology of ZnO formed when reacting solutions of ZnSO 4 and NaOH. The catalytic effect of hydroxide in excess relative to the stoichiometric ratio is considered. It is shown that, having fixed other reaction conditions, the end-products, particle structures and size strongly depend on the mole ratio of the precursors. The presence of zinc salt hydroxide species was confirmed at sub-stoichiometric ratios in slightly acidic conditions. At the stoichiometric ratio both zinc hydroxide and zinc oxide are formed, while only zinc oxide forms in an excess of hydroxide. The method of feeding the reactants into the reaction vessel also has a strong influence on the end-product properties, as does the reaction temperature. By control of these parameters the specific surface area could be varied from 10 to 33 m 2 g-1, the particle shape could be varied from equiaxed, through to star-like and needle-like, and the particle size may be varied from 50 to over 300 nm. © 2011 The Royal Society of Chemistry
Migrant and minority community organisations: funding, sustainability and ways forward
MODA (Migrant Organisations’ Development Agency) and Middlesex University have been working together on a research project about funding and resources available to migrant and minority organisations in London. This reports presents some of its key findings.
The aim of the project was to gather information about the role of minority and migrant organisations, including details about the services they provide, the community needs they address, the financial and organizational challenges they face and the creative ways they are
finding to cope. The research also aimed to explore the effects of the current economic and political climate on the sector and the role played by second tier organisations and other networks
On the formation of nanocrystalline active zinc oxide from zinc hydroxide carbonate
The decomposition of zinc hydroxide carbonate, Zn5(CO 3)2(OH)6 (ZHC), into the high surface area form of ZnO known as "active zinc oxide" is examined. In particular, the nucleation and evolution of the ZnO nanocrystals is of interest as the size of these particles controls the activity of the product. The decomposition process was studied using X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy and BET surface area measurements. At about 240°C ZHC decomposes to porous ZnO in a single step. The product material has a specific surface area in the range of 47-65 m 2 g-1 and initially has a crystallite size that is of the order of 10 nm. A further increase in temperature, however, causes the particles to coarsen to over 25 nm in diameter. In principle, the coarsening phenomenon may be interrupted to control the particle size. © Springer Science+Business Media 2014
X-ray-induced reduction of a surfactant/polyoxotungstate hybrid compound
© 2018 John Wiley & Sons, Ltd. We investigate the spontaneous reduction of a photochromic surfactant/polyoxotungstate hybrid during repeated X-ray photoelectron spectroscopy (XPS) scans and show how this effect may confound attempts to use soft X-rays to characterise materials of this nature. The W4f core-level spectra revealed a progressive increase of W5+ and W4+ species at the expense of W6+ as irradiation time increased. The samples developed a blue colour attributed to the presence of W4+ and/or W5+. The progressive photoreduction is also associated with a shift of the W6+ peak within the W4f spectrum to lower binding energies. This work highlights the need to consider inadvertent changes in oxidation state during X-ray photoelectron spectroscopy characterisation of samples containing photoreducible transition metals
Fouling and inactivation of titanium dioxide-based photocatalytic systems
Copyright © 2015 Taylor & Francis Group, LLC. Titanium dioxide is an effective photocatalyst for the breakdown of many environmental contaminants. The complex mixtures that can occur in water matrices can significantly affect the breakdown of the contaminants in water by titanium dioxide (TiO2). The authors discuss a wide variety of foulants and inhibitors of photocatalytic TiO2 systems and review different methods that can be effective for their fouling prevention. Approaches to regenerate a fouled or contaminated TiO2 catalysts are explored and the effect of substrates on immobilized titanium dioxide is also reviewed
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