2,831 research outputs found

    Inappropriate electrolyte repletion for patients undergoing endoscopic procedures

    Get PDF
    At Thomas Jefferson University Hospital (TJUH), there has been a perceived necessity among housestaff and fellows to routinely check and replete serum potassium and magnesium for inpatients prior to endoscopic procedures In addition, there was an unwritten policy that these electrolytes needed to be aggressively repleted, with a goal potassium above 4.0 and magnesium above 2.0 Contributing factors include absence of clear policy, fear of adverse outcomes during procedures, and fear of delay of procedures leading to increased hospital stay This practice has led to unwarranted lab draws, costs of lab tests and electrolyte riders, and possible delayed procedures Goals Clarify policies regarding electrolyte repletion Determine frequency of inappropriate electrolyte checking and repletion Determine monetary cost of this action Decrease frequency of inappropriate electrolyte lab check and repletionhttps://jdc.jefferson.edu/patientsafetyposters/1023/thumbnail.jp

    InGaN Microring Light-Emitting Diodes

    Get PDF
    The fabrication and performance of an InGaN light-emitting diode (LED) array based on a microring device geometry is reported. This design has been adopted in order to increase the surface area for light extraction and to minimize losses due to internal reflections and reabsorption. Electrical characteristics of these devices are similar to those of a conventional large-area LED, while the directed light extraction proves to be superior. In fact, these devices are found to be more efficient when operated at higher currents. This may be attributed to improved heat sinking due to the large surface area to volume ratio. The potential applications of these devices are also discussed.published_or_final_versio

    Recruiting and Retaining Individuals with Serious Mental Illness and Diabetes in Clinical Research: Lessons Learned from a Randomized, Controlled Trial.

    Full text link
    Abstract: Recruitment and retention of individuals with serious mental illness (SMI) and comorbid diabetes mellitus (DM) in research studies can be challenging with major impediments being difficulties reaching participants via telephone contact, logistic difficulties due to lack of transportation, ongoing psychiatric symptoms, and significant medical complications. Research staff directly involved in recruitment and retention processes of this study reviewed their experiences. The largest barriers at the macro, mediator, and micro levels identified in this study were inclement weather, transportation difficulties, and intermittent and inaccessible telephone contact. Barrier work-around practices included using the health system’s EHR to obtain current phone numbers, providing transportation assistance (bus passes or parking reimbursement), and flexible scheduling of appointments. Suggestions are intended to assist in planning for recruitment and retention strategies

    Ultra-Low Cost High-Density Two-Dimensional Visible-Light Optical Interconnects

    Get PDF
    © 2019 IEEE. Visible light communications have attracted considerable interest in recent years owing to the ability of low-cost light emitting diodes (LEDs) to act both as illumination sources and data transmitters with moderate data transmission rates. In this paper, we propose the formation of ultra-low cost visible-light integrated optical links by interfacing dense micro-pixelated LED arrays with matching multi-layered multimode polymer waveguide arrays. The combination of these two optical technologies can offer relatively high aggregate data densities ≥ 0.5 Tb/s/mm2 using very low cost components that can be directly interfaced with CMOS electronics and integrated onto standard printed circuit boards. Here, we present the basic system design and report the first proof-of-principle demonstration of such a visible light system employing 4×4 μLED arrays on a pitch matching four-layered waveguide array samples. Different interconnection topologies and light coupling schemes are investigated and their performance in terms of loss and crosstalk is compared. Data transmission of 2.5 Gb/s with a bit error rate within the forward-error correction threshold of 3.8×10-3 is achieved over a single μLED-waveguide channel using PAM-4 modulation and equalization. The results presented here demonstrate the potential of such ultra-low cost visible-light optical interconnects.UK EPSRC via the Ultra Parallel Visible Light Communications Project (EP/K00042X/1

    GaN micro-light-emitting diode arrays with monolithically integrated sapphire microlenses

    Get PDF
    A microdisk light emitting diode (micro-LED) with a monolithically integrated microlens array was demonstrated. The capability of the lenses in concentrating light emitted from microdisk LEDs was also demonstrated. The focal lengths of the microlenses were determined to be around 44 νm. The emission pattern of the LED emitters was found to be altered by the optical properties of the microlenses. The light emitted by the hybrid device was also found to be less divergent than a broad-area device.published_or_final_versio

    InGaN nano-ring structures for high-efficiency light emitting diodes

    Get PDF
    A technique based on the Fresnel diffraction effect for the fabrication of nano-scale site-controlled ring structures in InGaN/GaN multi-quantum well structures has been demonstrated. The ring structures have an internal diameter of 500 nm and a wall width of 300 nm. A 1 cm-1 Raman shift has been measured, signifying substantial strain relaxation from the fabricated structure. The 9 nm blueshift observed in the cathodoluminescence spectra can be attributed to band filling and/or screening of the piezoelectric field. A light emitting diode based on this geometry has been demonstrated. © 2005 American Institute of Physics.published_or_final_versio

    μlED-Based Single-Wavelength Bi-directional POF Link with 10 Gb/s Aggregate Data Rate

    Get PDF
    We report record 10 Gb/s bi-directional data transmission over a single 10 m SI-POF, by employing blue micro-light-emitting diodes (μLEDs) at a single wavelength, APD receivers and a PAM-32 modulation scheme. The implementation of 10 Gb/s LED-POF links takes advantage of the bi-directional configuration, which doubles the overall channel capacity, and APDs which provide an enhanced link power budget owing to their improved sensitivity compared with conventional PIN photodiodes. Moreover, the high spectral efficiency of the PAM-32 modulation scheme employed, together with equalization techniques, enable the full utilization of the link bandwidth and the transmission of data rates higher than those obtained with conventional on-off-keying (OOK). Simulation and experimental results demonstrate the feasibility of such a bi-directional link and simultaneous 5 Gb/s data transmission is realized in each direction, achieving an aggregate data rate of 10 Gb/s with a BER<10-3. The crosstalk penalty between the two directions of the link is measured to be less than 0.5 dB.This is the final version of the article. It first appeared from IEEE via http://dx.doi.org/10.1109/JLT.2015.244398

    2 Gb/s μlED-APD based visible light communications using feed-forward pre-equalization and PAM-4 modulation

    Get PDF
    Feed-forward pre-equalization is investigated to extend the transmission capability of μLED-based links, providing better receiver sensitivities up to 5dB compared with post-equalization. Error-free 2Gb/s free-space VLC over 0.6m is demonstrated using a PAM-4 modulated blue μLED and an APD receiver.This work is supported by the UK EPSRC via the UPVLC Project.This is the author accepted manuscript. The final version is available from IEEE via http://dx.doi.org/10.1109/ECOC.2015.734188

    6.25 Gb/s POF link using GaN μLED arrays and optically generated pulse amplitude modulation

    Get PDF
    Optically-generated PAM schemes using μLED arrays are implemented for high-speed POF links for the first time. 6.25Gb/s PAM-16 transmission is demonstrated using 4 μLEDs, exhibiting 3.8dB greater power-margin than a link with a single μLED.This work is supported by the UK Engineering and Physical Sciences Research Council (EPSRC) via the Ultra Parallel Visible Light Communication (UP-VLC) Project.This is the accepted manuscript of a paper published in CLEO: 2015 (X. Li, N. Bamiedakis, J. Wei, J. Mckendry, E. Xie, R. Ferreira, E. Gu, M. Dawson, R. V. Penty, and I. H. White, "6.25 Gb/s POF Link Using GaN μLED Arrays and Optically Generated Pulse Amplitude Modulation," in CLEO: 2015, OSA Technical Digest (online) (Optical Society of America, 2015), paper STu4F.7.). The final version is available at http://dx.doi.org/10.1364/CLEO_SI.2015.STu4F.7 © 2015 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited
    corecore