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No full textDecontamination is a combination of processes (including cleaning, disinfection and/or sterilization) used to render a reusable item safe for return to the operating theatre. Critical to this process are the prevention of drying and the implementation of an effective washer-disinfector process commonly utilizing enzymatic or alkaline detergents within an automated cycle. At this stage the choice of the main wash chemistry is crucial. A balance must be obtained between the vigorous removal of often dense contamination and the maintenance of surface integrity and instrument function. However, ineffective cleaning of surgical instruments may be a vector for the transmission of hospital acquired infections and assessment of cleaning efficacy is dependent on the minimal level of detection of the analytical method.Currently, following disinfection, instruments are subjected to visual evaluation often using magnifying/illuminated lenses to detect any evidence of residual soiling of damage whereby instruments are reprocessed or discarded. Although this method is clearly both rapid and simple to perform it undoubtedly suffers from serious issues of variability and sensitivity, in addition to being non-quantitative. Whilst this method readily detects the haem pigment in haemoglobin to levels as low as 10 ?g/cm2, bodily fluids without pigments are more difficult to visualise (REF?). Cerebral spinal fluid (CSF) is both colourless and odourless and has been shown to be a carrier of prion disease infection. Due to the realisation of these facts, European guidelines ISO EN15883 and the British Health Technical Memorandum (HTM) 2030 outline two techniques for the further assessment of instrument cleanliness: the Biuret and Ninhydrin test kits. Both require prior swabbing of an instrument surface to obtain a result and are based on colorimetric chemical changes although the methodologies behind these reactions differ. The Biuret technique utilises the reaction of copper ions with peptide bonds under alkaline conditions to form a complex which is then added to bicinchoninic acid (BCA) causing a purple colour change that can be readily visualised. The Ninhydrin test kit uses a reaction of amino acids, peptides and proteins with 1, 2, 3-indantrione monohydrate followed by a 30 min incubation at 110 ºC, although a Ninhydrin gel kit can also be used requiring incubation at only 57 ºC for 60 min. However, a recent study has shown that both the Biuret and Ninhydrin tests suffer from poor sensitivity, demonstrating a minimum level of detection by 75 % of volunteers of 6.7 ?g and 9.25 ?g of protein, respectively, on surgical grade stainless steel tokens1. The authors suggests that, as a result, large amounts of protein (up to 6.5 ?g) may remain undetected, therefore seriously underestimating levels of residual contamination. In practice, sensitivity is likely to be reduced further due to the difficulty in swabbing areas of surgical instruments such as teeth and box joints where contamination is likely to be harder to remove for analysis
Application of a fluorescent dual stain to assess decontamination of tissue protein and prion amyloid from surgical stainless steel during simulated washer-disinfector cycles
No full textCurrent World Health Organization guidelines pertaining to the reprocessing of surgical instruments in the face of potential iatrogenic transmission of Creutzfeldt-Jakob disease (iCJD) are incompatible for the vast majority of devices. This has led to the advent of a range of new decontamination measures. Even without the implementation of these new procedures, the incidence of proven iCJD through surgery remains low. In this study, existing decontamination processes in sterile service departments have been evaluated using simulated washer-disinfector cycles on surgical grade stainless steel wires inoculated with ME7 scrapie homogenate. The consequence of varying the soil drying times and choice of cycle pre-treatment on prion removal were evaluated. Assessment of residual contamination at each cycle phase was carried out with the application of a sensitive fluorescent staining procedure to identify both total protein and prion-associated amyloid. The study confirmed that immediate reprocessing following contamination was beneficial during the pre-treatment phase with either an enzymatic or pre-soak wetting agent. Final total protein levels at the end of the cycles, were not significantly different from those where the soil was allowed to dry. In addition, cycles involving a pre-treatment with either an enzymatic cleaner or pre-soak, whether the soil was allowed to dry or not, showed complete removal of detectable prion amyloid. The results suggest that current decontamination procedures, combined with immediate processing of surgical instruments, have the potential to be highly effective alone at reducing the risk of surgical transmission of CJ
Cold water cleaning of brain proteins, biofilm and bone - harnessing an ultrasonically activated stream
No full textIn the absence of sufficient cleaning of medical instruments, contamination and infection can result in serious consequences for the health sector and remains a significant unmet challenge. In this paper we describe a novel cleaning system reliant on cavitation action created in a free flowing fluid stream where ultrasonic transmission to a surface, through the stream, is achieved using careful design and control of the device architecture, sound field and the materials employed. Cleaning was achieved with purified water at room temperature, moderate fluid flow rates and without the need for chemical additives or the high power consumption associated with conventional strategies. This study illustrates the potential in harnessing an ultrasonically activated stream to remove biological contamination including brain tissue from surgical stainless steel substrates, S. epidermidis biofilms from glass, and fat/soft tissue matter from bone structures with considerable basic and clinical applications.</span
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Cold water cleaning of brain proteins, biofilm and bone - harnessing an ultrasonically activated stream
No full textIn the absence of sufficient cleaning of medical instruments, contamination and infection can result in serious consequences for the health sector and remains a significant unmet challenge. In this paper we describe a novel cleaning system reliant on cavitation action created in a free flowing fluid stream where ultrasonic transmission to a surface, through the stream, is achieved using careful design and control of the device architecture, sound field and the materials employed. Cleaning was achieved with purified water at room temperature, moderate fluid flow rates and without the need for chemical additives or the high power consumption associated with conventional strategies. This study illustrates the potential in harnessing an ultrasonically activated stream to remove biological contamination including brain tissue from surgical stainless steel substrates, S. epidermidis biofilms from glass, and fat/soft tissue matter from bone structures with considerable basic and clinical applications
Antimicrobial Activity of the Quinoline Derivative HT61 against Staphylococcus aureus Biofilms.
Full text linkStaphylococcus aureus biofilms are a significant problem in health care settings, partly due to the presence of a nondividing, antibiotic-tolerant subpopulation. Here we evaluated treatment of S. aureus UAMS-1 biofilms with HT61, a quinoline derivative shown to be effective against nondividing Staphylococcus spp. HT61 was effective at reducing biofilm viability and was associated with increased expression of cell wall stress and division proteins, confirming its potential as a treatment for S. aureus biofilm infections
Removal of dental biofilms with an ultrasonically-activated water stream
No full textAcidogenic bacteria within dental plaque biofilms are the causative agents of caries. Consequently, maintenance of a healthy oral environment with efficient biofilm removal strategies is important to limit caries, as well as halt progression to gingivitis and periodontitis. Recently, a novel cleaning device has been described using an ultrasonically activated stream (UAS) to generate a cavitation cloud of bubbles in a freely flowing water stream that has demonstrated the capacity to be effective at biofilm removal. In this study, UAS was evaluated for its ability to remove biofilms of the cariogenic pathogen Streptococcus mutans UA159, as well as Actinomyces naeslundii ATCC 12104 and Streptococcus oralis ATCC 9811, grown on machine-etched glass slides to generate a reproducible complex surface and artificial teeth from a typodont training model. Biofilm removal was assessed both visually and microscopically using high-speed videography, confocal scanning laser microscopy (CSLM), and scanning electron microscopy (SEM). Analysis by CSLM demonstrated a statistically significant 99.9% removal of S. mutans biofilms exposed to the UAS for 10 s, relative to both untreated control biofilms and biofilms exposed to the water stream alone without ultrasonic activation (P < 0.05). The water stream alone showed no statistically significant difference in removal compared with the untreated control (P = 0.24). High-speed videography demonstrated a rapid rate (151 mm2 in 1 s) of biofilm removal. The UAS was also highly effective at S. mutans, A. naeslundii, and S. oralis biofilm removal from machine-etched glass and S. mutans from typodont surfaces with complex topography. Consequently, UAS technology represents a potentially effective method for biofilm removal and improved oral hygiene
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