220 research outputs found

    Frequency of the Common MYH Mutations (G382D and Y165C) in MMR Mutation Positive and Negative HNPCC Patients

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    Recently mutations in the MYH gene have been associated with a milder form of adenomatous polyposis which is characterized by a variable level of colonic polyps ranging from a few to several hundred. In the context of HNPCC it is not unusual to identify patients with a smattering of polyps. The MYH gene product is involved in DNA repair and indeed the hMSH2/hMSH6 complex (both genes being essential elements of the DNA mismatch repair pathway) is required to stimulate MYH activity. We reasoned that because of the clinical similarity of a subset of HNPCC patients to those described with MYH mutations and the role of the hMSH2/hMSH6 complex in the activation of MYH protein that MYH mutations may account for a small proportion of HNPCC patients. In a study of 442 HNPCC patients we identified MYH mutations at the same frequency as that expected in the general population. Nevertheless, two HNPCC families were identified harbouring biallelic changes in MYH

    Critical thinking and diagnostic reasoning when advanced practitioners assess and treat skin conditions

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    Advanced clinical practitioner (ACP) roles require a broad range of knowledge of both medical and surgical medicine and the ability to work autonomously in a variety of settings. Despite around half of the UK adult population presenting with a skin condition requiring attention, this is something many ACPs feel unprepared to consult on. However, due to the complexity and large number of potential diagnoses, it is imperative that ACPs develop their confidence and knowledge to diagnosis, request investigations and initiate treatment for a patient with a skin complaint. In the first part of this clinical review the authors presented the key elements of history taking, consultation and assessment of the skin. This second clinical review discusses the main differential diagnoses, mimickers, common investigations and treatments. This article is designed to support novice ACPs from acute hospital settings to primary care to develop a foundation of understanding in the main diagnosis and treatment options that should be considered following a clinical assessment of patients’ skin out with the dermatology setting

    Translational trial outcomes for capsule endoscopy test devices

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    Current clinical standards in the endoscopic diagnosis of gastrointestinal diseases are primarily based on the use of optical systems. Ultrasound has established diagnostic credibility in the form of endoscopic ultrasound (EUS), however it is limited to examination of the upper gastrointestinal tract (oesophagus, stomach and upper (proximal) small bowel). Access to the remainder of the small bowel is currently limited to optical capsule endoscopes and a limited number of other modalities as these capsules are restricted to visual examination of the surface or mucosa of the gut wall. Ultrasound capsule endoscopy has been proposed to integrate microultrasound imaging capabilities into the existing capsule format and extend examination capabilities beyond the mucosa. To establish the ability of high frequency ultrasound to resolve the histological structure of the gastrointestinal tract, ex vivo scans of pig and human tissue were performed. This was done using 25 and 34 MHz single element, physically focused composite transducers mechanically scanned along the tissue. Tethered prototype devices were then developed with 30 MHz physically focused polyvinylidene fluoride (PVDF) single element transducers embedded for use in initial translational trials in the small bowel of porcine subjects. B-scan images from the ex vivo model validation and the in vivo trials are presented

    Refractive-index sensing with ultra-thin plasmonic nanotubes

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    We study the refractive-index sensing properties of plasmonic nanotubes with a dielectric core and ultra-thin metal shell. The few-nm thin metal shell is described by both the usual Drude model and the nonlocal hydrodynamic model to investigate the effects of nonlocality. We derive an analytical expression for the extinction cross section and show how sensing of the refractive index of the surrounding medium and the figure-of-merit are affected by the shape and size of the nanotubes. Comparison with other localized surface plasmon resonance sensors reveals that the nanotube exhibits superior sensitivity and comparable figure-of-merit

    In Vivo Characterization of a Wireless Telemetry Module for a Capsule Endoscopy System Utilizing a Conformal Antenna

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    This paper describes the design, fabrication, packaging, and performance characterization of a conformal helix antenna created on the outside of a 10 mm ×30 mm capsule endoscope designed to operate at a carrier frequency of 433 MHz within human tissue. Wireless data transfer was established between the integrated capsule system and an external receiver. The telemetry system was tested within a tissue phantom and in vivo porcine models. Two different types of transmission modes were tested. The first mode, replicating normal operating conditions, used data packets at a steady power level of 0 dBm, while the capsule was being withdrawn at a steady rate from the small intestine. The second mode, replicating the worst-case clinical scenario of capsule retention within the small bowel, sent data with stepwise increasing power levels of –10, 0, 6, and 10 dBm, with the capsule fixed in position. The temperature of the tissue surrounding the external antenna was monitored at all times using thermistors embedded within the capsule shell to observe potential safety issues. The recorded data showed, for both modes of operation, a low error transmission of 10−3 packet error rate and 10−5 bit error rate and no temperature increase of the tissue according to IEEE standards

    Hydrogeomorphology of the Hyporheic Zone: Stream Solute and Fine Particle Interactions With a Dynamic Streambed

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    Hyporheic flow in streams has typically been studied separately from geomorphic processes. We investigated interactions between bed mobility and dynamic hyporheic storage of solutes and fine particles in a sand-bed stream before, during, and after a flood. A conservatively transported solute tracer (bromide) and a fine particles tracer (5 μm latex particles), a surrogate for fine particulate organic matter, were co-injected during base flow. The tracers were differentially stored, with fine particles penetrating more shallowly in hyporheic flow and retained more efficiently due to the high rate of particle filtration in bed sediment compared to solute. Tracer injections lasted 3.5 h after which we released a small flood from an upstream dam one hour later. Due to shallower storage in the bed, fine particles were rapidly entrained during the rising limb of the flood hydrograph. Rather than being flushed by the flood, we observed that solutes were stored longer due to expansion of hyporheic flow paths beneath the temporarily enlarged bedforms. Three important timescales determined the fate of solutes and fine particles: (1) flood duration, (2) relaxation time of flood-enlarged bedforms back to base flow dimensions, and (3) resulting adjustments and lag times of hyporheic flow. Recurrent transitions between these timescales explain why we observed a peak accumulation of natural particulate organic matter between 2 and 4 cm deep in the bed, i.e., below the scour layer of mobile bedforms but above the maximum depth of particle filtration in hyporheic flow paths. Thus, physical interactions between bed mobility and hyporheic transport influence how organic matter is stored in the bed and how long it is retained, which affects decomposition rate and metabolism of this southeastern Coastal Plain stream. In summary we found that dynamic interactions between hyporheic flow, bed mobility, and flow variation had strong but differential influences on base flow retention and flood mobilization of solutes and fine particulates. These hydrogeomorphic relationships have implications for microbial respiration of organic matter, carbon and nutrient cycling, and fate of contaminants in streams

    Rebooting an Old Script by New Means: Teledildonics—The Technological Return to the ‘Coital Imperative’

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    Teledildonics, a form of digital-mediated sexual interaction, opens new possibilities for the understanding of sexual activity. At first glance, it disrupts conventional preconditions and assumptions about sexual interaction, by allowing the dimension of touch despite the physical distance between partners and, ultimately, promoting a sexual dimension definitely disconnected from the reproductive model of sexuality. However, by scrutinizing the design and functionality of the devices, as well as the discourses presented by three commercial companies—LovePalz, Lovense and Kiiroo—I suggest that this technology reinforces the ‘coital imperative’, by equating sexual interaction with penetration of the vagina by the penis. Although permitting other formulations, specifically for non-heterosexual couples, the penetrative act remains a presupposition. In spite of structurally disrupting the reproductive model of sex, teledildonics promotes its strongest corollary.info:eu-repo/semantics/publishedVersio
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