156 resultados para skin electrode
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This article describes the highly sensitive and selective determination of epinephrine (EP) using self-assembled monomolecular film (SAMF) of 1,8,15,22-tetraamino-phthalocyanatonickel(II) (4α-NiIITAPc) on Au electrode. The 4α-NiIITAPc SAMF modified electrode was prepared by spontaneous adsorption of 4α-NiIITAPc from dimethylformamide solution. The modified electrode oxidizes EP at less over potential with enhanced current response in contrast to the bare Au electrode. The standard heterogeneous rate constant (k°) for the oxidation of EP at 4α-NiIITAPc SAMF modified electrode was found to be 1.94×10−2 cm s−1 which was much higher than that at the bare Au electrode. Further, it was found that 4α-NiIITAPc SAMF modified electrode separates the voltammetric signals of ascorbic acid (AA) and EP with a peak separation of 250 mV. Using amperometric method the lowest detection limit of 50 nM of EP was achieved at SAMF modified electrode. Simultaneous amperometric determination of AA and EP was also achieved at the SAMF modified electrode. Common physiological interferents such as uric acid, glucose, urea and NaCl do not interfere within the potential window of EP oxidation. The present 4α-NiIITAPc SAMF modified electrode was also successfully applied to determine the concentration of EP in commercially available injection.
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Electropolymerized films of teraaminometallophthalocyanines (MTAPc; M = Ni and Co) with amino groups at α- (4α-MTAPc) and β- (4β-MTAPc) positions were prepared on glassy carbon (GC) and indium tin oxide (ITO) electrodes. It was found that the electropolymerization growth rate of 4α-MTAPc was less than that of 4β-MTAPc prepared under identical conditions. Further, the surface coverage of the polymerized 4β-MTAPc film was greater than that of 4α-MTAPc polymerized film. Atomic force microscopy (AFM), X-ray diffraction (XRD) and UV–visible spectroscopic studies were carried out for the polymerized films of 4α-NiIITAPc (p-4α-NiIITAPc) and 4β-NiIITAPc (p-4β-NiIITAPc) alone because both Ni(II) and Co(II) polymerized films show similar trend in electropolymerization and surface coverage values. AFM images show that p-4α-NiIITAPc film contains islands and the thickness of this film was nearly three times less than that of p-4β-NiIITAPc. XRD patterns for the two polymerized films reveal that p-4β-NiIITAPc film was relatively more crystalline than p-4α-NiIITAPc film. Further, the compactness of these films was scrutinized from their barrier properties toward [Fe(CN)6]3−/4− redox couple. The differences in the polymerization growth rate of 4α-MTAPc and 4β-MTAPc, and the thicknesses of the resultant polymerized films suggest that unlike 4β-MTAPc one or two amino groups might have not involved in electropolymerization in the case of 4α-MTAPc. Further, the influence of surface coverage on the electrocatalytic properties of the polymerized films was studied by taking p-4β-CoIITAPc and p-4α-CoIITAPc films as examples. The electrocatalytic oxygen reduction current was almost same at both the electrodes suggesting that only the surface species were involved in the electrocatalytic reduction of oxygen.
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Electropolymerized film of 3,3′,3″,3‴-tetraaminophthalocyanatonickel(II) (p-NiIITAPc) on glassy carbon (GC) electrode was used for the selective and stable determination of 3,4-dihydroxy-l-phenylalanine (l-dopa) in acetate buffer (pH 4.0) solution. Bare GC electrode fails to determine the concentration of l-dopa accurately in acetate buffer solution due to the cyclization reaction of dopaquinone to cyclodopa in solution. On the other hand, p-NiIITAPc electrode successfully determines the concentration of l-dopa accurately because the cyclization reaction was prevented at this electrode. It was found that the electrochemical reaction of l-dopa at the modified electrode is faster than that at the bare GC electrode. This was confirmed from the higher heterogeneous electron transfer rate constant (k0) of l-dopa at p-NiIITAPc electrode (3.35 × 10−2 cm s−1) when compared to that at the bare GC electrode (5.18 × 10−3 cm s−1). Further, it was found that p-NiIITAPc electrode separates the signals of ascorbic acid (AA) and l-dopa in a mixture with a peak separation of 220 mV. Lowest detection limit of 100 nM was achieved at the modified electrode using amperometric method. Common physiological interferents like uric acid, glucose and urea does not show any interference within the potential window of l-dopa oxidation. The present electrode system was also successfully applied to estimate the concentration of l-dopa in the commercially available tablets.
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This paper describes the electrocatalytic oxidation of ascorbic acid (AA) in phosphate buffer solution by the immobilized citrate capped gold nanoparticles (AuNPs) on 1,6-hexanedithiol (HDT) modified Au electrode. X-ray photoelectron spectrum (XPS) of HDT suggests that it forms a monolayer on Au surface through one of the two single bondSH groups and the other single bondSH group is pointing away from the electrode surface. The free single bondSH groups of HDT were used to covalently attach colloidal AuNPs. The covalent attachment of AuNPs on HDT monolayer was confirmed from the observed characteristic carboxylate ion stretching modes of citrate attached with AuNPs in the infra-red reflection absorption spectrum (IRRAS) in addition to a higher reductive desorption charges obtained for AuNPs immobilized on HDT modified Au (Au/HDT/AuNPs) electrode in 0.1 M KOH when compared to HDT modified Au (Au/HDT) electrode. The electron transfer reaction of [Fe(CN)6]4−/3− was markedly hindered at the HDT modified Au (Au/HDT) electrode while it was restored with a peak separation of 74 mV after the immobilization of AuNPs on Au/HDT (Au/HDT/AuNPs) electrode indicating a good electronic communication between the immobilized AuNPs and the underlying bulk Au electrode through a HDT monolayer. The Cottrell slope obtained from the potential-step chronoamperometric measurements for the reduction of ferricyanide at Au/HDT/AuNPs was higher than that of bare Au electrode indicating the increased effective surface area of AuNPs modified electrode. The Au/HDT/AuNPs electrode exhibits excellent electrocatalytic activity towards the oxidation of ascorbic acid (AA) by enhancing the oxidation peak current to more than two times with a 210 mV negative shift in the oxidation potential when compared to a bare Au electrode. The standard heterogeneous electron transfer rate constant (ks) calculated for AA oxidation at Au/HDT/AuNPs electrode was 5.4 × 10−3 cm s−1. The oxidation peak of AA at Au/HDT/AuNPs electrode was highly stable upon repeated potential cycling. Linear calibration plot was obtained for AA over the concentration range of 1–110 μM with a correlation coefficient of 0.9950. The detection limit of AA was found to be 1 μM. The common physiological interferents such as glucose, oxalate ions and urea do not show any interference within the detection limit of AA. The selectivity of the AuNPs modified electrode was illustrated by the determination of AA in the presence of uric acid.
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BACKGROUND The incidence of skin cancer, both melanoma and keratinocyte cancers (KC) is rising throughout the world, specifically squamous cell carcinomas(SCC) and basal cell carcinoma(BCC), being the most common of all cancers. OBJECTIVE To determine trends in incidence of Melanoma, BCC and SCC among 1.7 million members of Maccabi Healthcare Services from 2006 to 2011. METHODS Data on newly diagnosed Melanoma, SCC and BCC cases was collected from the MHS Cancer Registry and based on histology reports from the centralized pathology lab. Age-specific and overall age-adjusted European standardized rates were computed. Trends were estimated by calculating Average Annual Percentage Change(AAPC). RESULTS During the six year study period, a total of 16,079 subjects were diagnosed with at least one BCC, 4,767 with SCC and 1,264 with invasive melanoma. Age-standardized incidence rates were 188, 58 and 17 per 100,000 person years for BCC, SCC and melanoma, respectively. All lesions were more common among males and primarily affected the elderly. BCC rates were stable throughout the study period(AAPC -0.7%, 95%CI -4.5% to 3.2%) while SCC incidence increased significantly(AAPC 15.5%, 95%CI: 2.6% to 30.0%). In contrast, melanoma rates continuously decreased with a significant AAPC of -3.0%, 95%CI (-4.5 to -0.1). CONCLUSIONS Previously unreported, the incidence of KC in Israel is high. The disparities in incidence trends between SCC, BCC and melanoma allude to their different etiologies. These findings underscore the importance of continuous monitoring, education and prevention programs in a growing high risk population.
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In traditional communication and information theory, noise is the demon Other, an unwelcome disruption in the passage of information. Noise is "anything that is added to the signal between its transmission and reception that is not intended by the source...anything that makes the intended signal harder to decode accurately". It is in Michel Serres' formulation, the "third man" in dialogue who is always assumed, and whom interlocutors continually struggle to exclude. Noise is simultaneously a condition and a by-product of the act of communication, it represents the ever present possibility of disruption, interruption, misunderstanding. In sonic or musical terms noise is cacophony, dissonance. For economists, noise is an arbitrary element, both a barrier to the pursuit of wealth and a basis for speculation. For Mick (Jeremy Sims) and his mate Kev (Ben Mendelsohn) in David Caesar's Idiot Box (1996), as for Hando (Russell Crowe) and his gang of skinheads in Geoffrey Wright's Romper Stomper (1992), or Dazey (Ben Mendelsohn) and Joe (Aden Young) in Wright's Metal Skin (1994) and all those like them starved of (useful) information and excluded from the circuit - the information poor - their only option, their only point of intervention in the loop, is to make noise, to disrupt, to discomfort, to become Serres' "third man", "the prosopopoeia of noise" (5).
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Objective. To test the impact of a theory-based, SMS (text message)-delivered behavioural intervention (Healthy Text) targeting sun protection or skin self-examination behaviours compared to attention-control. Method. Overall, 546 participants aged 18–42 years were randomised using a computer-generated number list to the skin self-examination (N = 176), sun protection (N = 187), or attention-control (N = 183) text messages group. Each group received 21 text messages about their assigned topic over 12 months (12 weekly messages for three months, then monthly messages for the next nine months). Data was collected via telephone survey at baseline, three-, and 12-months across Queensland from January 2012 to August 2013. Results. One year after baseline, the sun protection (mean change 0.12; P = 0.030) and skin self-examination groups (mean change 0.12; P = 0.035) had significantly greater improvement in their sun protection habits (SPH) index compared to the attention-control group (reference mean change 0.02). The increase in the proportion of participants who reported any skin self-examination from baseline to 12 months was significantly greater in the skin self-examination intervention group (103/163; 63%; P < 0.001) than the sun protection (83/173; 48%), or attention-control (65/165; 36%) groups. There was no significant effect of the intervention for participants who self-reported whole-body skin self-examination, sun tanning behaviour, or sunburn behaviours. Conclusion. The Healthy Text intervention was effective in inducing significant improvements in sun protection and any type of skin self-examination behaviours.
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We propose and mathematically examine a theory of calcium profile formation in unwounded mammalian epidermis based on: changes in keratinocyte proliferation, fluid and calcium exchange with the extracellular fluid during these cells' passage through the epidermal sublayers, and the barrier functions of both the stratum corneum and tight junctions localised in the stratum granulosum. Using this theory, we develop a mathematical model that predicts epidermal sublayer transit times, partitioning of the epidermal calcium gradient between intracellular and extracellular domains, and the permeability of the tight junction barrier to calcium ions. Comparison of our model's predictions of epidermal transit times with experimental data indicates that keratinocytes lose at least 87% of their volume during their disintegration to become corneocytes. Intracellular calcium is suggested as the main contributor to the epidermal calcium gradient, with its distribution actively regulated by a phenotypic switch in calcium exchange between keratinocytes and extracellular fluid present at the boundary between the stratum spinosum and the stratum granulosum. Formation of the extracellular calcium distribution, which rises in concentration through the stratum granulosum towards the skin surface, is attributed to a tight junction barrier in this sublayer possessing permeability to calcium ions that is less than 15 nm/s in human epidermis and less than 37 nm/s in murine epidermis. Future experimental work may refine the presented theory and reduce the mathematical uncertainty present in the model predictions.
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Evidence is needed for the acceptability and user preferences of receiving skin cancer-related text messages. We prepared 27 questions to evaluate attitudes, satisfaction with program characteristics such as timing and spacing, and overall satisfaction with the Healthy Text program in young adults. Within this randomised controlled trial (age 18-42 years), 546 participants were assigned to one of three Healthy Text message groups; sun protection, skin self-examination, or attention-control. Over a 12-month period, 21 behaviour-specific text messages were sent to each group. Participants’ preferences were compared between the two interventions and control group at the 12-month follow-up telephone interview. In all three groups, participants reported the messages were easy to understand (98%), provided good suggestions or ideas (88%), and were encouraging (86%) and informative (85%) with little difference between the groups. The timing of the texts was received positively (92%); however, some suggestions for frequency or time of day the messages were received from 8% of participants. Participants in the two intervention groups found their messages more informative, and triggering behaviour change compared to control. Text messages about skin cancer prevention and early detection are novel and acceptable to induce behaviour change in young adults.
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The dynamic nature of tissue temperature and the subcutaneous properties, such as blood flow, fatness, and metabolic rate, leads to variation in local skin temperature. Therefore, we investigated the effects of using multiple regions of interest when calculating weighted mean skin temperature from four local sites. Twenty-six healthy males completed a single trial in a thermonetural laboratory (mean ± SD): 24.0 (1.2) °C; 56 (8%) relative humidity; < 0.1 m/s air speed). Mean skin temperature was calculated from four local sites (neck, scapula, hand and shin) in accordance with International Standards using digital infrared thermography. A 50 x 50 mm square, defined by strips of aluminium tape, created six unique regions of interest, top left quadrant, top right quadrant, bottom left quadrant, bottom right quadrant, centre quadrant and the entire region of interest, at each of the local sites. The largest potential error in weighted mean skin temperature was calculated using a combination of a) the coolest and b) the warmest regions of interest at each of the local sites. Significant differences between the six regions interest were observed at the neck (P < 0.01), scapula (P < 0.001) and shin (P < 0.05); but not at the hand (P = 0.482). The largest difference (± SEM) at each site was as follows: neck 0.2 (0.1) °C; scapula 0.2 (0.0) °C; shin 0.1 (0.0) °C and hand 0.1 (0.1) °C. The largest potential error (mean ± SD) in weighted mean skin temperature was 0.4 (0.1) °C (P < 0.001) and the associated 95% limits of agreement for these differences was 0.2 to 0.5 °C. Although we observed differences in local and mean skin temperature based on the region of interest employed, these differences were minimal and are not considered physiologically meaningful.
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Purpose: Skin temperature assessment has historically been undertaken with conductive devices affixed to the skin. With the development of technology, infrared devices are increasingly utilised in the measurement of skin temperature. Therefore, our purpose was to evaluate the agreement between four skin temperature devices at rest, during exercise in the heat, and recovery. Methods: Mean skin temperature (T̅sk) was assessed in thirty healthy males during 30 min rest (24.0± 1.2°C, 56 ± 8%), 30 min cycle in the heat (38.0 ± 0.5°C, 41 ± 2%), and 45 min recovery(24.0 ± 1.3°C, 56 ± 9%). T̅sk was assessed at four sites using two conductive devices(thermistors, iButtons) and two infrared devices (infrared thermometer, infrared camera). Results: Bland–Altman plots demonstrated mean bias ± limits of agreement between the thermistors and iButtons as follows (rest, exercise, recovery): -0.01 ± 0.04, 0.26 ± 0.85, -0.37 ± 0.98°C; thermistors and infrared thermometer: 0.34 ± 0.44, -0.44 ± 1.23, -1.04 ± 1.75°C; thermistors and infrared camera (rest, recovery): 0.83 ± 0.77, 1.88 ± 1.87°C. Pairwise comparisons of T̅sk found significant differences (p < 0.05) between thermistors and both infrared devices during resting conditions, and significant differences between the thermistors and all other devices tested during exercise in the heat and recovery. Conclusions: These results indicate poor agreement between conductive and infrared devices at rest, during exercise in the heat, and subsequent recovery. Infrared devices may not be suitable for monitoring T̅sk in the presence of, or following, metabolic and environmental induced heat stress.
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Overview The incidence of skin tears, pressure injuries and chronic wounds increases with age [1-4] and therefore is a serious issue for staff and residents in Residential Aged Care Facilities (RACFs). A pilot project funded in Round 2 of the Encouraging Best Practice in Residential Aged Care (EBPRAC) program by the then Australian Government Department of Health and Ageing found that a substantial proportion of residents in aged care facilities experienced pressure injuries, skin tears or chronic wounds. It also found the implementation of the evidence based Champions for Skin Integrity (CSI) model of wound care was successful in significantly decreasing the prevalence and severity of wounds in residents, improving staff skills and knowledge of evidence based wound management, increasing staff confidence with wound management, increasing implementation of evidence based wound management and prevention strategies, and increasing staff awareness of their roles in evidence based wound care at all levels [5]. Importantly, during the project, the project team developed a resource kit on evidence based wound management. Two critical recommendations resulting from the project were that: - The CSI model or a similar strategic approach should be implemented in RACFs to facilitate the uptake of evidence based wound management and prevention - The resource kit on evidence based wound management should be made available to all Residential Aged Care Facilities and interested parties A proposal to disseminate or rollout the CSI model of wound care to all RACFs across Australia was submitted to the department in 2012. The department approved funding from the Aged Care Services Improvement Healthy Ageing Grant (ACSIHAG) at the same time as the Round 3 of the Encouraging Better Practice in Aged Care (EBPAC) program. The dissemination involved two crucial elements: 1. The updating, refining and distribution of a Champions for Skin Integrity Resource Kit, more commonly known as a CSI Resource Kit and 2. The presentation of intensive one day Promoting Healthy Skin “Train the Trainer” workshops in all capital cities and major regional towns across Australia Due to demand, the department agreed to fund a second round of workshops focussing on regional centres and the completion date was extended to accommodate the workshops. Later, the department also decided to host a departmental website for a number of clinical domains, including wound management, so that staff from the residential aged care sector had easy access to a central repository of helpful clinical resource material that could be used for improving the health and wellbeing of their older adults, consumers and carers. CSI Resource Kit Upgrade and Distribution: At the start of the project, a full evidence review was carried out on the material produced during the EBPRAC-CSI Stage 1 project and the relevant evidence based changes were made to the documentation. At the same time participants in the EBPRAC-CSI Stage 1 project were interviewed for advice on how to improve the resource material. Following this the documentation, included in the kit, was sent to independent experts for peer review. When this process was finalised, a learning designer and QUT’s Visual Communications Services were engaged to completely refine and update the design of the resources, and combined resource kit with the goal of keeping the overall size of the kit suitable for bookshelf mounting and the cost at reasonable levels. Both goals were achieved in that the kit is about the same size as a 25 mm A4 binder and costs between $19.00 and $28.00 per kit depending on the size of the print run. The dissemination of the updated CSI resource kit was an outstanding success. Demand for the kits was so great that a second print run of 2,000 kits was arranged on top of the initial print run of 4,000 kits. All RACFs across Australia were issued with a kit, some 2,740 in total. Since the initial distribution another 1,100 requests for kits has been fulfilled as well as 1,619 kits being distributed to participants at the Promoting Healthy Skin workshops. As the project was winding up a final request email was sent to all workshop participants asking if they required additional kits or resources to distribute the remaining kits and resources. This has resulted in requests for 200 additional kits and resources. Feedback from the residential aged care sector and other clinical providers who have interest in wound care has been very positive regarding the utility of the kit, (see Appendix 4). Promoting Healthy Skin Workshops The workshops also exceeded the project team’s initial objective. Our goal of providing workshop training for staff from one in four facilities and 450 participants was exceeded, with overwhelming demand for workshop places resulting in the need to provide a second round of workshops across Australia. At the completion of the second round, 37 workshops had been given, with 1286 participants, representing 835 facilities. A number of strategies were used to promote the workshops ranging from invitations included in the kit, to postcard mail-outs, broadcast emailing to all facilities and aged care networks and to articles and paid advertising in aged care journals. The most effective method, by far, was directly phoning the facilities. This enabled the caller to contact the relevant staff member and enlist their support for the workshop. As this is a labour intensive exercise, it was only used where numbers needed bolstering, with one venue rising from 3 registrants before the calls to 53 registrants after. The workshops were aimed at staff who had the interest and the capability of implementing evidence-based wound management within their facility or organisation. This targeting was successful in that a large proportion (68%) of participants were Registered Nurses, Nurse Managers, Educators or Consultants. Twenty percent were Endorsed Enrolled Nurses with the remaining 12% being made up of Personal Care Workers or Allied Health Professionals. To facilitate long term sustainability, the workshop employed train-the-trainer strategies. Feedback from the EBPRAC-CSI Stage 1 interviews was used in the development of workshop content. In addition, feedback from the workshop conducted at the end of the EBPRAC-CSI Stage 1 project suggested that change management and leadership training should be included in the workshops. The program was trialled in the first workshop conducted in Brisbane and then rolled out across Australia. Participants were asked to complete pre and post workshop surveys at the beginning and end of the workshop to determine how knowledge and confidence improved over the day. Results from the pre and post surveys showed significant improvements in the level of confidence in attendees’ ability to implement evidence based wound management. The results also indicated a significant increase in the level of confidence in ability to implement change within their facility or organisation. This is an important indication that the inclusion of change management/leadership training with clinical instruction can increase staff capacity and confidence in translating evidence into practice. To encourage the transfer of the evidence based content of the workshop into practice, participants were asked to prepare an Action Plan to be followed by a simple one page progress report three months after the workshop. These reports ranged from simple (e.g. skin moisturising to prevent skin tears), to complex implementation plans for introducing the CSI model across the whole organisation. Outcomes described in the project reports included decreased prevalence of skin tears, pressure injuries and chronic wounds, along with increased staff and resident knowledge and resident comfort. As stated above, some organisations prepared large, complex plans to roll out the CSI model across their organisation. These plans included a review of the organisation’s wound care system, policies and procedures, the creation of new processes, the education of staff and clients, uploading education and resource material onto internal electronic platforms and setting up formal review and evaluation processes. The CSI Resources have been enthusiastically sought and incorporated into multiple health care settings, including aged care, acute care, Medicare Local intranets (e.g. Map of Medicine e-pathways), primary health care, community and home care organisations, education providers and New Zealand aged and community health providers. Recommendations: Recommendations for RACFs, aged care and health service providers and government Skin integrity and the evidence-practice gap in this area should be recognised as a major health issue for health service providers for older adults, with wounds experienced by up to 50% of residents in aged care settings (Edwards et al. 2010). Implementation of evidence based wound care through the Champions for Skin Integrity model in this and the pilot project has demonstrated the prevalence of wounds, wound healing times and wound infections can be halved. A national program and Centre for Evidence Based Wound Management should be established to: - expand the reach of the model to other aged care facilities and health service providers for older adults - sustain the uptake of models such as the Champions for Skin Integrity (CSI) model - ensure current resources, expertise and training are available for consumers and health care professionals to promote skin integrity for all older adults Evidence based resources for the CSI program and similar projects should be reviewed and updated every 3 – 4 years as per NH&MRC recommendations Leadership and change management training is fundamental to increasing staff capacity, at all levels, to promote within-organisation dissemination of skills and knowledge gained from projects providing evidence based training Recommendations for future national dissemination projects A formal program of opportunities for small groups of like projects to share information and resources, coordinate activities and synergise education programs interactively would benefit future national dissemination projects - Future workshop programs could explore an incentive program to optimise attendance and reduce ‘no shows’ - Future projects should build in the capacity and funding for increased follow-up with workshop attendees, to explore the reasons behind those who are unable to translate workshop learnings into the workplace and identify factors to address these barriers.
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Early diagnosis of melanoma leads to the best prognosis for patients and may be more likely achieved when those who are at high risk for melanoma undergo regular and systematic monitoring. However, many people rarely or never see a dermatologist. Risk prediction models (recently reviewed by Usher-Smith et al ) could assist to triage people into preventive care appropriate for their risk profile. Most risk prediction models contain measures of phenotype including skin, eye and hair colour as well as genetic mutations. Almost all also contain the number and size of naevi, as well as the presence of naevi with atypical features which are independently associated with melanoma risk. In the absence of formal population-based screening programs for melanoma in most countries worldwide, people with high risk phenotypes may need to consider regular monitoring or self-monitoring of their naevi , especially since the vast majority of melanomas are found by people themselves or their friend and relatives. Another group of patients that will require regular monitoring are patients who have been successfully treated for their first melanoma, whose risk to develop a second melanoma is greatly increased . In a US study of 89,515 melanoma survivors those with a previous diagnosis of melanoma had a 9-fold increased risk of developing subsequent melanoma compared with the general population, equating to a rate of 3.76 per 1000 person-years, while in an Australian study, risk of subsequent melanoma was 6 per 1000 person-years. Regular follow-up is therefore essential for melanoma survivors, especially during the first few years after initial melanoma diagnosis.