635 research outputs found

    Testing medical drills for noise emissions

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    Copyright @ 2007 TUT PressA comparative study of drills from a range of manufacturers was carried out in the laboratory. These tests were made under a variety of loading conditions to assess the characteristics of the noise likely in the dentist’s surgery. Details of the test setup are given, and some of the issues in analysing the results considered. Simultaneous Recordings were made of the noise on a minidisk recorder, a hand held sound meter, and a sound analyser. The results from these are considered. These are significant for dentist’s hearing, and the patient’s perception of visiting the dentists. The performance of different designs of pneumatic drill varies much with type and load

    Noise reduction of dental drill noise

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    Dental drills produce a characteristic noise that is uncomfortable for patients and is also known to be harmful to dentists under prolonged exposure. It is therefore desirable to protect the patient and dentist whilst allowing two-way communication, which will require a headphone - type system. Re-establishing good communication between the dentist and patient will be achieved through a combination of three noise cancellation technologies, namely, Passive Noise Control (PNC), Adaptive Filtering (AF) and Active Noise Control (ANC). This paper describes how far a test-rig has been developed to achieve sufficient noise reduction that the uncomfortable noise can no longer be heard

    Is heavy eccentric calf training superior to wait-and-see, sham rehabilitation, traditional physiotherapy and other exercise interventions for pain and function in mid-portion Achilles tendinopathy?

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    Background: Mid-portion Achilles tendinopathy (AT) is prevalent amongst athletic and non-athletic populations with pain, stiffness and impaired function typically reported. While different management options exist, loading protocols remain the best available intervention and have been shown to be effective in the management of AT. Trials investigating loading in AT have used a variety of different protocols, and recent narrative reviews suggest that no protocol is superior to another when comparing outcomes in pain and function. However, there has been no systematic review or meta-analysis completed to determine this. Furthermore, the narrative review did not consider wait-and-see or sham interventions, thus a systematic review and met-analysis which includes wait-and see or sham interventions is warranted. Methods: A systematic review and meta-analyses will be conducted as per the PRISMA guidelines. The databases PUBMED, CINAHL (Ovid) and CINAHL (EBSCO) will be searched for articles published from inception to 31 December 2017. Our search focuses on studies examining the improvement of pain and function when completing a loading program for mid-portion AT. Only randomised/ quasi-randomised trials will be included while case reports and case series will be excluded. The primary outcome assessing pain and function will be the Victorian Institute Sports Assessment - Achilles (VISA-A). Two reviewers will screen articles, extract data and assess the risk of bias independently with a third reviewer resolving any disagreements between the two reviewers. A meta-analysis will then be performed on the data (if appropriate) to determine if the traditional heavy load calf training protocol described by Alfredson is superior to wait-and-see, sham intervention, traditional physiotherapy, and other forms of exercise rehabilitation. Discussion: This systematic review and meta-analysis will allow us to investigate if there are difference in pain and function when comparing wait-and-see, sham interventions, traditional physiotherapy and different exercise interventions to the traditional heavy eccentric calf training protocol for mid-portion Achilles tendon pain. Systematic review registration: PROSPERO registration number CRD42018084493

    Emergent global patterns of ecosystem structure and function from a mechanistic general ecosystem model

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    Anthropogenic activities are causing widespread degradation of ecosystems worldwide, threatening the ecosystem services upon which all human life depends. Improved understanding of this degradation is urgently needed to improve avoidance and mitigation measures. One tool to assist these efforts is predictive models of ecosystem structure and function that are mechanistic: based on fundamental ecological principles. Here we present the first mechanistic General Ecosystem Model (GEM) of ecosystem structure and function that is both global and applies in all terrestrial and marine environments. Functional forms and parameter values were derived from the theoretical and empirical literature where possible. Simulations of the fate of all organisms with body masses between 10 µg and 150,000 kg (a range of 14 orders of magnitude) across the globe led to emergent properties at individual (e.g., growth rate), community (e.g., biomass turnover rates), ecosystem (e.g., trophic pyramids), and macroecological scales (e.g., global patterns of trophic structure) that are in general agreement with current data and theory. These properties emerged from our encoding of the biology of, and interactions among, individual organisms without any direct constraints on the properties themselves. Our results indicate that ecologists have gathered sufficient information to begin to build realistic, global, and mechanistic models of ecosystems, capable of predicting a diverse range of ecosystem properties and their response to human pressures

    Epithelioma of Malherbe: new ultrasound patterns

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    <p>Abstract</p> <p>Backround</p> <p>Calcifying epithelioma of Malherbe, or Pilomatricoma, is considered an uncommon cutaneous neoplasia, normally occurring in children as a solitary, firm, asymptomatic, hard, subcutaneous, slowly growing nodule on the face, neck, or proximal upper extremity. In literature, two Pilomatricoma ultrasound patterns are described: the totally calcified nodule and the hypoechoic nodule with internal calcific foci. High frequency ultrasound has not yet been applied for routine diagnosis of Pilomatricoma. The aim of the study was to retrospectively identify specific ultrasound features.</p> <p>Methods</p> <p>We retrieved 124 histologically Pilomatricoma cases: 28 patients with 32 lesions were preoperatively evaluated with ultrasound.</p> <p>Results</p> <p>22/32 have shown a solid formation, hypoechoic, with a sharp outline. Of these 22, 10 lesions were completely calcifying and 12 partially calcified. In 3/32 lesions with uncertain diagnosis, ultrasounds showed a complex/mixed pattern with pseudo-fluid areas and microspots. 7/32 lesions with US different diagnosis included 3 complex lesions, 2 cystic lesions and 2 solid nodular lesions.</p> <p>Conclusion</p> <p>In addition to well-known ultrasound patterns (completely calcified and partially calcified) we identified three new, not yet described, patterns that constitute the 31% of the cases: complex, pseudocistyc and pseudotumoral.</p

    Impacts of climate change on plant diseases – opinions and trends

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    There has been a remarkable scientific output on the topic of how climate change is likely to affect plant diseases in the coming decades. This review addresses the need for review of this burgeoning literature by summarizing opinions of previous reviews and trends in recent studies on the impacts of climate change on plant health. Sudden Oak Death is used as an introductory case study: Californian forests could become even more susceptible to this emerging plant disease, if spring precipitations will be accompanied by warmer temperatures, although climate shifts may also affect the current synchronicity between host cambium activity and pathogen colonization rate. A summary of observed and predicted climate changes, as well as of direct effects of climate change on pathosystems, is provided. Prediction and management of climate change effects on plant health are complicated by indirect effects and the interactions with global change drivers. Uncertainty in models of plant disease development under climate change calls for a diversity of management strategies, from more participatory approaches to interdisciplinary science. Involvement of stakeholders and scientists from outside plant pathology shows the importance of trade-offs, for example in the land-sharing vs. sparing debate. Further research is needed on climate change and plant health in mountain, boreal, Mediterranean and tropical regions, with multiple climate change factors and scenarios (including our responses to it, e.g. the assisted migration of plants), in relation to endophytes, viruses and mycorrhiza, using long-term and large-scale datasets and considering various plant disease control methods

    Clinical and pathological features of BRCA1 associated carcinomas in a hospital-based sample of Dutch breast cancer patients

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    Thus far, studies investigating the differences in tumour characteristics between breast cancer in BRCA1-carriers and other patients, have focused on highly selected groups of patients, potentially limiting the conclusions that can be drawn. Previously, we had identified 10 patients with BRCA1 germline mutations in a hospital-based series of 642 breast cancer patients not selected for age or family history. The aim of this analysis is to investigate the clinical and pathological features of these BRCA1 associated carcinomas as compared to other breast cancers in this representative sample. Tumours from patients with BRCA1 germline mutations (n= 10) were compared to an age-matched sample of other patients (n= 50) from the same cohort. The following characteristics were considered: axillary nodal status and tumour size, histologic parameters (tumour type, histologic grade, mitotic rate, tubule formation, nuclear grade, CIS and lymphangio invasion) and expression of several proteins (oestrogen and progesterone receptors, cyclin D1, p53, HER2/neu, E-cadherin). In BRCA1associated tumours receptors for oestrogen and progesterone were expressed less frequently (respectively P= 0.001 and P= 0.002) than in controls, which is in line with findings from other studies. Other differences were also in accordance with findings from other studies, although not statistically significant. We conclude that the features of BRCA1 associated tumours detected in a hospital-based series of breast cancer patients not selected for family history of age at diagnosis are similar to tumours in cases selected for family history or age at diagnosis. © 2001 Cancer Research Campaign  http://www.bjcancer.co
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