91,846 research outputs found
A sports headlight retrofitted on magnifying loupes: A simple and cheap method for daily use
Medical professionals such as doctors, nurses and paramedics often use headlight to examine or to perform surgical intervention in the patients. However, there are concerns related to its use such as comfort for the user, mobility and asepsis for the cable, availability in the departments plus cost effectiveness. The concept of a retrofitted 1-watt sports headlight (adjusted on magnifying loupes) would give quick access to a light source, be available and reliable at any place, save vital funds and would be environmentally friendly as the battery can be replaced. The same concept can be applied to pre-hospital emergency care and disaster medicine as well. BACKGROUND Headlights with fibre optic cables have being used for two decades as an adjunct to the operating theatre lighting. The cable-powered headlights pose, to our experience, some limitations for the operating team: Smooth personnel circulation around the operating field is hindered by repeated unplugging and re-plugging of the cable when surgeon and assistants change sides. Protocols for draping and asepsis have to accommodate the cumbersome cable and the light source and in addition are time consuming and arising issues of flexibility. The weight of the headlight and cable may cause health issues for the bearer (head ache, low back pain) [1]. Portable surgical headlights have also been available for the last decade for a not negligible cost. They are powered by a battery pack, attached to the torso/waist and connected to the headlight by a shorter cable. They are priced at hundreds of pounds. METHOD As an alternative to cumbersome cables and expensive ‘ad hoc’ designs, we use a retrofitted 1-watt sports headlight with a weight of 100 grams. We acquired that for $ 14.99 (approximately £10) from an outdoor specialist retailer (Petzl America, Clearfield, Utah, USA). The headlight is powered by three 1.5 Volt AAA batteries and provides 60 lumen of luminous flux (Fig.1). We have wrapped the elastic bands of the headlight around the corresponding horizontal (axial circumferential) and sagittal elements of the headband, where the magnifying loupes are mounted (Keeler Ltd., Clewer Hill Road, Windsor SL4 4AA). The headlight can be aimed by tilting the housing (Fig.1, 2). DISCUSSION The luminous flux from our headlight according to our experience in cardiothoracic surgery is adequate for a variety of procedures: femoral and axillary arterial access, harvesting internal thoracic (mammary) arteries, open pulmonary resections, valve surgery. Being fully portable without cable, light source or pouches, it is especially handy outside the operating suite (ITU, A&E, wards) for emergency re-explorations for bleeding, secondary wound closures, application of vacuum therapy dressings, trauma, for ECMO work etc. Finally, we have had no evidence of thermal injury, as has being reported from strong xenon beams [2]. This simple affordable headlight system can be easily adapted to the needs of the entire spectrum of surgical specialties, especially those using magnifying loupes. Therefore, can be part of basic life support kits for use in prehospital emergency care, disaster and military medicine [3]. The device has the following advantages: 1. ‘‘Two-in-one’’ function of Loupes and Torch. 2. Battery can be changed (so no need to throw away the item) and is environmentally friendly 3. No need for asepsis 4. Cost effective 5. Availability everywhere In conclusion, we believe this is a practical medical device
A Mechanism for Hadron Molecule Production in p pbar(p) Collisions
We propose a mechanism allowing the formation of loosely bound molecules of
charmed mesons in high energy proton-(anti)proton collisions.Comment: 4 pages, 3 figure
Translated Poisson approximation to equilibrium distributions of Markov population processes
The paper is concerned with the equilibrium distributions of continuous-time
density dependent Markov processes on the integers. These distributions are
known typically to be approximately normal, and the approximation error, as
measured in Kolmogorov distance, is of the smallest order that is compatible
with their having integer support. Here, an approximation in the much stronger
total variation norm is established, without any loss in the asymptotic order
of accuracy; the approximating distribution is a translated Poisson
distribution having the same variance and (almost) the same mean. Our arguments
are based on the Stein-Chen method and Dynkin's formula.Comment: 18 page
Long-term outcome after tricuspid valvectomy in a neonate with Candida endocarditis : a case report
Tricuspid valvectomy is a rare surgical intervention, and knowledge regarding long-term outcome in children is lacking. We report a favourable outcome 11 years after tricuspid valvectomy in early infancy without subsequent surgery or other cardiac interventions. Specific criteria for timing of re-intervention are lacking. Application of adult tricuspid and pulmonary regurgitation recommendations is helpful but has limitations
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An evaluation of DIADEM assisted online form completion
The DIADEM project aims to develop a web-based application in the form of an Expert System (ES) to assist cognitively impaired older-adult users in the task of interacting with and completing online transactions. Having recently developed the first experimental version of the application, this study reports on the preliminary findings of user trials carried out in three European countries top evaluate this early version of the application. Of the 94 users that took part in the trials, 77 were identified as users that were likely to present with some degree of mild cognitive impairment, and thus were included in the analysis stage. The key findings of the study indicate that users of DIADEM assisted form filling seemed report comparatively high-levels of satisfaction, particularly when considered against what is considered a typical level of satisfaction for this user group. Furthermore, as a result of a statistical analysis, the application appears to provide significantly increased levels of assistance for users presenting with higher levels of cognitive impairments, and therefore achieves its goal of catering for this particular target user group
Reply to a Commentary "Asking photons where they have been without telling them what to say"
Interesting objections to conclusions of our experiment with nested
interferometers raised by Salih in a recent Commentary are analysed and
refuted.Comment: Published version (Frontiers in Physics) to revised version of the
Commentar
High surface area, emulsion-templated carbon foams by activation of polyHIPEs derived from Pickering emulsions.
Carbon foams displaying hierarchical porosity and excellent surface areas of >1400 m2/g can be produced by the activation of macroporous poly(divinylbenzene). Poly(divinylbenzene) was synthesized from the polymerization of the continuous, but minority, phase of a simple high internal phase Pickering emulsion. By the addition of KOH, chemical activation of the materials is induced during carbonization, producing Pickering-emulsion templated carbon foams, or carboHIPEs, with tailorable macropore diameters and surface areas almost triple that of those previously reported. The retention of the customizable, macroporous open-cell structure of the poly(divinylbenzene) precursor and the production of a large degree of microporosity during activation leads to tailorable carboHIPEs with excellent surface areas
Quantum thermodynamics at critical points during melting and solidification processes
We systematically explore and show the existence of finite-temperature
continuous quantum phase transition (CTQPT) at a critical point, namely, during
solidification or melting such that the first-order thermal phase transition is
a special case within CTQPT. Infact, CTQPT is related to chemical reaction
where quantum fluctuation (due to wavefunction transformation) is caused by
thermal energy and it can occur maximally for temperatures much higher than
zero Kelvin. To extract the quantity related to CTQPT, we use the ionization
energy theory and the energy-level spacing renormalization group method to
derive the energy-level spacing entropy, renormalized Bose-Einstein
distribution and the time-dependent specific heat capacity. This work
unambiguously shows that the quantum phase transition applies for any finite
temperatures.Comment: To be published in Indian Journal of Physics (Kolkata
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Impacts of variable renewable energy on wholesale markets and generating assets in the United States: A review of expectations and evidence
We synthesize available literature, data, and analysis on the degree to which growth in variable renewable energy (VRE) has impacted or might in the future impact bulk power system assets, pricing, and costs in the United States. Most studies of future scenarios indicate that VRE reduces wholesale energy prices and capacity factors of thermal generators. Traditional baseload generators are more exposed to these changing market conditions than low-capital cost and more flexible intermediate and peak-load generators. From analysis of historical data we find that VRE is already influencing the bulk power market through changes in temporal and geographic patterns areas with higher levels of VRE. The most significant observed impacts have concentrated in areas with significant VRE and/or nuclear generation along with limited transmission, with negative pricing also often occurring during periods with lower system-wide load. So far, however, VRE, has had a relatively modest impact on historical average annual wholesale prices across entire market regions, at least in comparison to other drivers. The reduction of natural gas prices is the primary contributor to the decline in wholesale prices since 2008. Similarly, VRE impacts on thermal plant retirements have been limited and there is little relationship between the location of recent retirements and VRE penetration levels. Although impacts on wholesale prices have been modest so far, impacts of VRE on the electricity market will be more significant under higher VRE penetrations
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